Baibakov S. A., engineer at JSC VTI

1. Current situation and problems.

Due to the peculiarities climatic conditions uninterrupted supply of thermal energy to the population and industry in Russia is a pressing social and economic problem. According to various sources, approximately 2020 million Gcal were produced for heat supply purposes in 2000. Over 45% of the total consumption of all types of fuel was spent on this, which is approximately 2 times more than fuel consumption for the needs of the electric power industry and corresponds to the fuel intensity of all other sectors of the economy.

Currently, heat supply to consumers in large settlements is mainly produced and will be produced in the future from sufficiently powerful centralized heating systems (DHS), which have large thermal power plants or district boiler houses as heat sources.

A significant part of the heat energy needs in our country, and especially in cities with a high concentration of heat loads, is traditionally met by large central heating systems based on steam turbine CHP plants with heating turbines of various capacities, i.e. There is a widespread use of district heating, the use of which objectively allows for significant savings in fossil fuels. Thus, the combined generation of thermal and electrical energy in Russia from various sources allows saving from 20 to 30% of fuel compared to separate generation.

IN modern conditions The development of district heating and heat supply systems based on it began to experience competition from decentralized schemes and separate generation of thermal and electrical energy, due to the following circumstances.

The efficiency of power plants with condensing turbines has increased significantly and reaches 40 - 43%. At the same time, it was possible to increase the efficiency of heating boiler houses, the value of which exceeds the efficiency of power boilers of thermal power plants, and the efficiency of using fuel from small boiler houses can practically reach 100%. All this leads to a decrease in relative fuel economy during district heating. In addition, the development of district heating requires significant initial costs, and the payback period for the creation of large thermal power plants is about ten years. In modern economic conditions, this situation, taking into account the mobility factor, objectively leads to a transition to heat supply from quick-payback, automated and highly economical boiler houses of various capacities, including rooftop and factory-ready house boiler plants, despite the fact that the specific capital costs for such boiler houses are much higher similar indicator for thermal power plants.

One of the main problems with the traditional DHS scheme is the factor of reliability of heat supply. As already noted, the accepted location of base and peak heat sources, the development of heat supply modes and the values ​​of network water parameters were determined without taking this factor into account. As a result, the following situation arose.

The concentration of thermal power and the radial-dead-end structure of heating networks have very limited capabilities for reserving the thermal power of heat sources. Emergency heat transfers can be carried out mainly through the end sections of heating networks that have low throughput. In accordance with this, emergency situations at the heat source or at the head sections of heating networks can lead to a significant and long-term reduction in heat supply to consumers.

To increase the reliability of heat supply at the heat source, it is possible to use backup heat-generating equipment (steam heat exchangers) with steam supplied from station steam collectors or from extractions with higher steam parameters and sectioning the collectors of cogeneration plants of thermal power plants.

In heating networks, increasing the reliability of heat supply is ensured by various methods of redundancy and duplication of pipelines, which leads to increased costs of heating networks and the complication of their circuits. With long main heating networks, increased reliability is ensured by sectioning main pipelines, laying several lines of pipelines with a smaller diameter and organizing jumpers between them. In addition, it is planned to connect consumers to jumper pipelines between adjacent mains, thereby providing the possibility of two-way heat supply.

Another factor that negatively affects the reliability of heating networks is the use of a fairly high temperature schedule of 150/70 o C. With this schedule, per 1 o C change in the outside air temperature there is approximately a 3.0 o C change in the temperature of the network water in the supply line. Accordingly, with possible relatively rapid intraday changes in weather conditions associated with an increase or decrease in air temperature during the heating period by 7-10 o C, a change in the temperature in the supply line by 21-30 o C is required. At the same time, changes in air temperature and, accordingly, water in pipelines are usually cyclic in nature.

In these conditions, operating experience as a measure to improve reliability involves the use of cutting the temperature curve to a maximum temperature of 120-130 o C, which leads to a lack of heat supply for heating. When installing load regulators (water temperature in the heating circuit) at heating points of consumers with an independent heating connection circuit, the use of cutting the temperature curve can lead to a significant increase in water consumption in the heating network and a significant change (complication) in the hydraulic regime of the heating networks.

A decrease in the attractiveness of obtaining heat from heat supply systems using district heating leads to the disconnection of consumers and their transition to other sources of thermal energy. At the same time, production volumes are falling and heat tariffs for other consumers are increasing.

In order to increase the attractiveness of heat supply based on district heating, it is necessary to take organizational and technical measures to increase the reliability and efficiency of heat production and transport, allowing for thoughtful and comprehensive solutions to existing problems, taking into account the expected increase in heat loads of existing systems and deterioration of main equipment, and especially those installed at thermal power plants peak boilers.

However, as follows from published materials on foreign experience heat supply organizations, currently in European countries(Denmark, Germany) the creation of large centralized heat supply systems based on the parallel connection to a common heating network of several sources of various capacities with combined production of heat and electricity (Mini-CHP, CCGT, GTU CHPP) has become widespread.

This approach is due to the significant fuel savings obtained when using district heating and the ability to most effectively solve ecological problems when burning organic fuel. At the same time, the regulation of heat supply in the systems under consideration is carried out in accordance with the schedule of quantitative and qualitative regulation at a maximum design temperature in the supply line at the level of 110 - 130 o C. Normal operation of heat supply systems in these conditions is possible only under the condition of complete automation of thermal energy consumers.

2. Analysis of existing proposals for the structure and schemes of the central heating system.

Modern central heating systems are a complex engineering complex of thermal energy sources (main and peak) and heat consumers, interconnected by heating networks for various purposes and balances, having characteristic thermal and hydraulic regimes with given coolant parameters. The magnitude of the parameters and the nature of their changes are determined by the technical capabilities of the main structural elements heat supply systems (sources, heat networks and consumers), economic feasibility and, to a large extent, accumulated experience in the creation and operation of such systems.

Recently, close attention has been paid to increasing the efficiency of combined heat generation and heat supply systems based on it. Many authors and organizations have developed various proposals on possible directions for changing the structural diagrams of such systems. Wherein we're talking about not about the use of new equipment, such as the use of steam-gas cycles for district heating, which in itself makes it possible to increase the efficiency of heat supply, but rather about the development of unconventional schemes for heat supply systems in general, in which the advantages of combined heat energy production are used to the greatest extent.

One of such proposals is the well-known proposal from the technical literature /1/ by Doctor of Technical Sciences. Andryushchenko A.I., the essence of which is the transition to a centralized supply of heat from thermal power plants only for hot water supply with its supply to heat consumption areas according to a single-pipe scheme. In this case, the heating load is provided by peak sources located directly in the areas of heat consumption with different compositions of heat-generating equipment and corresponding heating networks. The supply of water and heat from thermal power plants to two-pipe district heating networks is carried out in the form of their replenishment to compensate for direct water withdrawal for hot water supply in district networks, carried out according to an open scheme.

The use of such a central heating scheme makes it possible to increase the efficiency of combined generation by reducing the temperature of heat removal from the heating outputs of turbines with a stable annual load for heat supply.

However, heat supply systems with a similar structure can obviously be used in completely new construction, as well as in the reorganization of a heat supply scheme that involves the use of either a suburban CPP or a new CHPP with heat supplied to existing district heating networks, which use city block boiler houses as heat sources. Those. the use of the proposal under consideration requires a special organization of the system, characterized by the concentration of a significant load of hot water supply and the construction of heating networks for its transmission to areas of heat consumption.

The proposed scheme cannot be used for existing urban heat supply systems based on large thermal power plants based on the practical impossibility of transferring the hot water supply load to one of the sources. In addition, when using open hot water supply schemes, the need to create appropriate water treatment with high productivity and the availability of source water of a certain quality should be taken into account.

Several options for changing the connection schemes for peak sources in heat supply systems and the operating conditions of heating networks are given by the authors from the Ulyanovsk State Technical University in the monograph /2/.

Basically two proposals can be considered.

The first of them proposes to connect peak boiler houses at thermal power plants in parallel to network heaters and transfer the operation of heating networks to a lower temperature schedule using central quantitative or qualitative-quantitative regulation.

In this regard, it should be said that with modern automation schemes for heating points, a central change in water flow at the heat source is impossible, since water flow is determined by regulators at the heat consumer. In addition, the possibility of complying with restrictions on permissible water flows through turbine network heaters in the event of significant changes in flow rates in heating networks, which may require shutting down the heat supply turbines and operating them in a purely condensing mode, raises doubts.

In addition, for existing heat supply systems, a direct transition to a lower temperature schedule is also not possible, since with the same heat load, the significantly increased flow of network water cannot be passed through heating networks with the same pipeline diameters.

The second proposal considers the possibility of transitioning to complete decentralization of peak power installations of heat supply systems with its production directly from consumers. This proposal is also unlikely to be economically justified in terms of the total costs of the heat supply system, although, according to the authors, it allows for significant fuel savings.

So, it is proposed to use either electric heaters or house gas boilers as peak sources. All this together will obviously be much more expensive than the reconstruction of a peak water heating boiler house at a thermal power plant, since it will require relocation of either electrical networks or gas pipes. In addition, the use of electricity for heating purposes, as previous experience shows, allows one to obtain economic benefits only if there is an excess of cheap electricity produced, for example, by hydroelectric power plants.

The authors practically do not consider the operating modes of heating networks under the proposed schemes.

One of the latest proposals made by a group of authors from Belarus (Skoda A.N. et al.), which consists in switching heat supply from thermal power plants to three-pipe heating network schemes with separate heat supply for heating and hot water supply /3/. At the same time, at the thermal power plant, the hot water supply load is provided mainly through the use of the condenser heating bundle and the selection of the lower stage, and the heat supply for heating is produced from the upper heating extraction.

The proposed version of the heat supply system diagram has a number of advantages. The efficiency of the turbine increases due to the elimination of a purely ventilation passage and the generation of electricity from thermal consumption while reducing the parameters of heat removal from the cycle. At the same time, the operating modes of thermal heating networks are improved by stabilizing the hydraulic regime and making it possible to reduce the water temperature in the supply line at positive air temperatures in accordance with the heating schedule, due to the absence of the need to break the temperature schedule. The use of storage tanks for hot water supply, installed in areas of heat consumption, also makes it possible to have a stable hydraulic and thermal regime in the pipelines of the hot water supply system from thermal power plants.

For the above SCT scheme, it is necessary to install equipment for preparing water for hot water supply at the CHP plant, and in addition, the use of such a scheme in existing systems is practically impossible to implement, since almost all heating networks from the CHP plant require additional laying of pipelines for hot water supply networks. The proposed scheme can be considered as an option when creating new centralized heat supply systems.

The above works examine in detail mainly direct heat sources (cogeneration equipment of turbines and peak boiler houses) and increasing efficiency in heat production, but insufficient attention is paid to the conditions and operating modes of connected heating networks and heat consumers, as well as issues of creating integral systems based on the proposed options. This especially concerns the possibilities of using the above proposals for use in already established central heating systems with a traditional scheme.

However, the presence of the above problems with centralized heat supply and the possible increase in heat loads in cities will require raising the question of the feasibility of their reconstruction and modernization. At the same time, existing problems must be solved in a comprehensive manner, taking into account existing conditions and possible operating modes of heating networks and consumers.

3. Proposals for changing the schemes of existing central heating systems.

As the main directions for achieving the goals set above, one should first of all consider proposals that allow for the possible decentralization of heat sources and a reduction in the temperature schedule of heating networks.

For heat supply systems with a traditional structure, reducing the temperature schedule of heating networks is an expensive and difficult task. This is determined mainly by the possibilities of regulating the heat supply for heating at consumer heating points and the pipeline diameters adopted when designing heating networks.

Below we propose a possible option for changing the structure of currently operating central heating stations, the implementation of which will make it possible to ensure the fulfillment of the specified conditions at the lowest cost.

It is proposed to reconstruct the heat supply system, transferring peak heat sources from thermal power plants to areas of heat consumption. At the same time, the peak boilers at the thermal power plant that require reconstruction are dismantled, and new peak heat sources are equipped on the heating networks of all large outputs of the thermal power plant and are connected to existing mains at intermediate points. A schematic diagram of the heat supply system with such a transfer of peak sources is shown in Fig. 1, which also shows the initial diagram of the SCT (Fig. 1 a) with a traditional structure.

Hot water boilers can be used as peak sources, as well as various other types of heat generating equipment, including combined cycle power plants or gas turbine power plants. The choice of the type of peak source is generally determined based on the results of technical and economic calculations.

The transfer of peak sources to areas of heat consumption divides heating networks with connected consumers into two zones: the zone between the thermal power plant and the point of connection of the peak source (CHP zone); and the zone after the peak source (peak boiler zone). At the same time, different temperature (temperature curves) and corresponding hydraulic regimes can be maintained in both zones. As shown in Fig. 1, switching on peak sources via network water can be done either in series with the heating equipment of the CHP plant, or in parallel with the equipment of the CHP plant. Each connection scheme has its own advantages or disadvantages.

When connected in series, a large flow of water with a relatively high temperature in front of the source will pass through the peak source, which is important when using hot water boilers. This scheme provides for the supply of heat only to the peak source zone in the absence of the possibility of delivering thermal power to the CHP zone.

With a parallel connection, a reduced flow rate with the return temperature at the inlet passes through the peak source, but at the same time it is possible to supply water and heat to the heating networks of the CHP area, thereby providing the possibility of reserving the thermal power of the CHP. A mixing pump is installed at the peak source.

In real conditions, both parallel and series connection of peak sources can be used simultaneously. The choice of specific schemes is determined by the hydraulic characteristics of existing heating networks and the necessary backup conditions.

The proposed change in the structure of the heat supply system makes it possible to reduce the thermal power supplied directly from the thermal power plant to the power level of the heating equipment of the turbines. Under this condition, the existing water flow can be passed through existing pipelines without changing the diameter, which makes it possible to switch to a lower temperature schedule in the CHP area.

The length of heating networks after the peak source is comparatively less than the total length of the network of the original system, which allows for large pressure (pressure) losses, provided that the same available pressure is ensured at the most distant consumers. In accordance with this, in networks after the peak source it is also possible to switch to a reduced schedule with increased flow rates of network water.

The proposed structural diagram of the central heating system leads to the decentralization of heat sources with the possibility of their mutual redundancy and at the same time makes it possible to switch to a lower temperature schedule in heating networks, which should ensure increased reliability of heat supply. The transition to the proposed structural scheme of the central heating system will only require bringing the automation of consumer heating points to the required level.

In addition to these advantages, the proposed scheme allows you to increase the connected load and power of the heat supply system in certain areas of the heating network by increasing the power of peak sources, without changing the diameters of the pipelines of the rest of the network and the characteristics of other heat sources included in the central heating system.

It should be noted that the hydraulic and thermal conditions of heating networks and heat sources, among other conditions, also depend on the location of the connection of the peak source to the heating network, i.e. from removing the connected peak source from the thermal power plant.

As an example of determining the indicators of the modes and assessing the main conditions for the reconstruction of the central heating system, the required parameters and operating modes were considered when changing the layout of the centralized heat supply system with a conditional design heat load of consumers of 1 Gcal/h.

The initial heating network is connected to consumers only with a heating load at a design temperature in the premises of +18 o C. Under these conditions and the temperature schedule of the traditional scheme of 150/70 o C, the water consumption in the network is constant and equal to 12.5 t/h.

It was assumed that the heating coefficient for the original traditional scheme is 0.5, i.e. half of the design load of the system is covered from the turbine heating outputs. The other half is provided by the peak boiler room. The graph for covering the thermal load of the heating supply system depending on the outside air temperature (relative heating load), adopted based on the condition of the maximum heat load of the heating turbines of the CHP plant, is shown in Fig. 2

Rice. 2 Schedule for covering the thermal load of the heating system.

For preliminary analysis, we will assume that the connection of the heat load is distributed evenly over the heating network, which is one dead-end main line of varying diameter along the length of the network. The total relative length of the network is 1.

Schemes of the initial heat supply system and the system after transferring the peak source (peak boiler house) to the heat consumption area are shown in Fig. 3. In the same fig. The symbols used in the following are given for the main parameters of the SCT modes.

A. Initial (traditional) SCT scheme

b. Transformed SCT circuit

Rice. 3 SCT conversion diagram and symbols.

Legend:

1 - Cogeneration equipment of CHP

2 - Peak source (peak boiler room)

To assess changes in the hydraulic regimes of the heat supply system, it was assumed that in the heating network with a traditional scheme there is a linear change in pressure along the length of the pipelines. In this case, the relative available pressure at the thermal power plant under the traditional scheme is equal to 1, and the stability of the network (the ratio of the available pressure at the subscriber input to the available pressure at the thermal power plant) is 0.2, i.e. the available pressure at the last consumer is equal to 20% of the developed pressure at the thermal power plant.

Based on the results of the calculations, the technical feasibility of implementing the transfer of the peak source to the heat consumption area and the recommended operating modes of the heat supply system will be shown. It should also be taken into account that the choice of basic parameters and solutions (power ratio, location of the peak source, accepted temperature schedules, etc.) is obviously determined not only by purely technical, but also by technical and economic conditions. The proposed material does not consider technical and economic conditions.

For the new heat supply system, the same schedule for covering the total thermal load of the system was adopted as for the original network, which is shown in Fig. 2, i.e., the peak source provides half the load under design conditions and the heating coefficient for the central district heating system as a whole remains equal to 0.5.

We will assume that for consumers connected to the network after the transferred peak source (PC zone), a heating temperature schedule of 130/70 o C is accepted. For consumers in the CHP zone, the calculated temperature schedule is accepted lower based on the possibility of turbine heat extraction and equal to 120/70 o WITH.

Provided that consumer heating points are automated, the temperature in the return line of the network will not change during reconstruction and will remain equal to this temperature for the original heating network.

The possible point of connection of the peak source to the heating networks under the accepted conditions is determined by the hydraulic mode of the original system and the conditions of the resulting hydraulic modes when transferring the peak source, for which the requirement of ensuring the previous available pressures at the connected consumers must be met.

As shown by the calculations of the thermal-hydraulic modes of the transformed heat supply system, the point of connection of the peak source closest to the thermal power plant, provided that the specified available pressures are provided at the connected consumers, is 60% of the total length of the original heating network, i.e., it is removed by 0.6 relative units of the total length of the network from the thermal power plant. At the same time, the estimated heat load of consumers in the CHP zone will be 0.6 Gcal/h, and in the peak boiler zone 0.4 Gcal/h.

For the central heating system, after reconstruction, the original schedule for covering the total thermal loads of the system is preserved. However, the load coverage graphs for the CHP and peak boiler zones for the conditions of Fig. 2 are more complex.

The graph for covering the thermal loads of consumers in the CHP zone depending on the relative heating load is shown in Fig. 4, graph of coverage of thermal loads of consumers in the peak boiler zone - in Fig. 5

In Fig. Figure 4 shows graphs of changes in the load of consumers in the CHP zone and heat supply from the CHP. A graph of heat supply from the thermal power plant to the peak source zone (to the PC zone) is also given. The latter, at relative loads greater than 0.83 (at low outside temperatures), has negative values, which indicates the need to supply heat to the CHP zone from a peak source.

Figure 5 shows graphs of the load of consumers in the PC zone and the heat supply from the peak source. In the same fig. a graph of heat supply to the PC zone from the thermal power plant is also shown, which at relative loads greater than 0.83 has negative values, indicating, as already noted, that heat is supplied from the peak source to the thermal power plant zone.

Temperature graphs of the central heating system for the CHP zone and the peak boiler room are shown in Fig. 6, which also shows the temperature graph of the original MCT for comparison.

As follows from Fig. 6, the temperature graph from the CHP of the converted heat supply system has a complex dependence on the outside air temperature. The maximum temperature under design conditions corresponds, as indicated earlier, to 120 o C, and the minimum temperature of network water from the thermal power plant at the start (end) of the heating period is taken to be 70 o C. The graph under consideration has a break point at a relative load equal to 0.5, corresponding to the peak switching point boiler room The temperature at this point determines the highest water flow in the pipelines of the CHP zone, transmitted to the PC zone, which determines the most intense hydraulic regime of the CHP zone and the heat supply system as a whole. The temperature at the break point was determined based on the conditions for ensuring the necessary hydraulic conditions for the connected consumers at the accepted connection point of the portable peak source.

It should be noted that the temperature level in the supply line from the heating part of the thermal power plant determines the efficiency of the combined generation of thermal and electrical energy, and the lower it is, the higher the specific combined production.

Corresponding to the above data on temperatures in various parts of the heating system circuit at the accepted point of transfer of the peak source, graphs of water consumption depending on the relative heating load (outside air temperature) in various sections of the heating system circuit are shown in Fig. 7. For comparison, the figure shows the required flow rate of network water from the thermal power plant for the original heat supply system at a temperature curve of 150/70 o C.

As follows from Fig. 7, the water consumption from the thermal power plant in the reconstructed heat supply system is significantly lower than the initial value of 12.5 t/h and increases as the outside air temperature decreases from 6.5 to 10.0 t/h. The water flow through the peak source with a decrease in air temperature first decreases from 4.1 to 3.6 t/h and then increases to a maximum value under design conditions equal to 8.7 t/h.

Just as during heat supply, in the reconstructed central heating system there are water flows between the CHP zone and the PC zone. Water consumption by zones is shown in Fig. 8 and 9.

Figure 8 shows a graph of the total water consumption for consumers in the CHP zone, a graph of water consumption from the CHP and a graph of water supply to the CHP zone from the peak source. The latter has negative values ​​for relative loads less than 0.83 and shows that at these relative loads there is a supply of water from the pipelines of the CHP area (from the CHP) to the peak source.

In Fig. Figure 9 shows graphs of water consumption in the peak source zone, as well as graphs of water consumption for consumers in the PC zone, water consumption through the peak source and water consumption from the thermal power plant to the PC zone. In this case, the maximum value of water flow supplied from the thermal power plant to the peak source is noted at a relative load equal to 0.5 and corresponding to the switching point of the peak boiler house. The value of this flow rate is 3.3 t/h.

Based on the above data on the calculated hydraulic mode of the original network and the conditions for connecting the thermal load, calculations of hydraulic modes were carried out and piezometric graphs of the reconstructed network were constructed for characteristic relative loads (outside air temperatures), shown in Fig. 10.

In Fig. piezometric graphs are shown at the design temperature of the outside air, at the most intense hydraulic mode corresponding to the relative load at the point at which the peak source starts operating and, for comparison, a piezometric graph of the heating network of the original heat supply system. As follows from Fig. 10 requirements for hydraulic modes for the converted central heating system (requirements for available pressures of connected consumers) are met in all modes.

The obtained calculation results show the possibility of technical implementation of the proposed change in the central heating system scheme, while the results are presented for one of possible options. For the accepted conditions of changing the scheme, the costs of pumping coolant increase and the indicators of specific combined heat energy production deteriorate, since heat is released from the heating equipment of the CHP plant at higher temperatures in the supply line of the heating network of the CHP zone than for the original SCT circuit. However, for the modified design of the heat supply system, the level of maximum temperatures in the supply line will decrease, which, together with the decentralization of heat sources, will increase the reliability of heat supply with a slight decrease in its efficiency.

The technical and economic indicators of the above-considered option for reconstructing the central heating system for given design temperature schedules are determined by the accepted point of connection of the peak heat source to the heating network. Thus, removing the connection point of the peak source from the thermal power plant leads to an improvement in the performance of hydraulic modes, namely, to an increase in the available pressures in the heating network. This circumstance makes it possible to either increase the water flow from the thermal power plant when the temperature in the supply line of the thermal power plant zone decreases, thereby improving the performance of the combined production of thermal and electrical energy, or to reduce the available pressures at the thermal power plant and the peak source, reducing the additional energy consumption for pumping the coolant. In this case, one should also take into account the change in heat losses in heating networks associated with changes in the temperature regime of heating networks

The choice of the main parameters of the variable SCT scheme is the result of technical and economic optimization calculations and is not considered in the proposed material.

4. Conclusions.

1. Existing developed centralized heat supply systems based on large urban thermal power plants with a traditional layout require reconstruction, both in terms of the equipment used and in the structural diagrams. Such reconstruction should lead, first of all, to increasing the reliability of heat supply and providing opportunities to increase the connected load.

2. The proposals for changing the schemes of heat supply systems given in modern technical literature give rise to a number of comments. Most of these proposals make it possible to increase the efficiency of using combined generation, but are practically of little use for existing central district heating systems due to the significant costs of their implementation, associated mainly with heating networks. Other proposals require a comprehensive analysis and additional calculations for heat supply modes and coolant parameters at various points in the circuits with determination of the total costs of creating and operating such systems.

3. The scheme proposed in the article for the reconstruction of traditional heat supply systems, associated with the transfer of peak sources to the area of ​​heat consumption and their connection to existing heating mains, is technically feasible and makes it possible to increase the reliability of heat supply by improving backup conditions and switching to lower temperature schedules. In this case, there is no need to re-wire heating networks, but only to bring the automation of consumer heat load connection circuits to the modern level.

Bibliography

1. Andryushchenko A. I. Combined systems heat supply. // “Thermal power engineering”. 1997. No. 5. pp. 2-6.

2. Sharapov V.I., Orlov M.E. Technologies for ensuring peak load of heat supply systems. M.: Publishing House “Heat Supply News”, 2006.-208 p.; ill.

3. Skoda A. N., Skoda V. N., Kukharchik V. M. Improvement of combined heat supply technologies. "Electric stations". 2008. No. 10. From 16-17.

Energy saving in heat supply systems

Completed by: students of group T-23

Salazhenkov M.Yu

Krasnov D.

Introduction

Today, energy saving policy is a priority direction in the development of energy and heat supply systems. In fact, at every state enterprise, plans for energy saving and increasing the energy efficiency of enterprises, workshops, etc. are drawn up, approved and implemented.

The country's heat supply system is no exception. It is quite large and cumbersome, consumes colossal amounts of energy and at the same time there are no less colossal losses of heat and energy.

Let's consider what the heat supply system is, where the greatest losses occur, and what sets of energy-saving measures can be applied to increase the “efficiency” of this system.

Heating systems

Heat supply – supply of heat to residential, public and industrial buildings (structures) to meet the domestic (heating, ventilation, hot water supply) and technological needs of consumers.

In most cases, heating is the creation of a comfortable indoor environment - at home, at work or in public place. Heat supply also includes heating tap water and water in swimming pools, heating greenhouses, etc.

The distance over which heat is transported in modern district heating systems reaches several tens of km. The development of heat supply systems is characterized by an increase in the power of the heat source and the unit capacity of installed equipment. The thermal capacity of modern thermal power plants reaches 2-4 Tcal/h, district boiler houses 300-500 Gcal/h. In some heat supply systems, several heat sources work together on common heating networks, which increases the reliability, maneuverability and cost-effectiveness of heat supply.

Water heated in the boiler room can circulate directly in the heating system. Hot water is heated in the heat exchanger of the hot water supply system (DHW) to a lower temperature, about 50–60 °C. Return water temperature can be an important factor in boiler protection. The heat exchanger not only transfers heat from one circuit to another, but also effectively copes with the pressure difference that exists between the first and second circuits.

The required floor heating temperature (30 °C) can be obtained by adjusting the temperature of the circulating hot water. A temperature difference can also be achieved by using a three-way valve that mixes hot water with return water in the system.

Regulation of heat supply in heat supply systems (daily, seasonal) is carried out both in the heat source and in heat-consuming installations. In water heating systems, the so-called central quality control of heat supply is usually carried out according to the main type of heat load - heating or a combination of two types of load - heating and hot water supply. It consists of changing the temperature of the coolant supplied from the heat supply source to the heating network in accordance with the accepted temperature schedule (that is, the dependence of the required water temperature in the network on the outside air temperature). Central qualitative regulation is complemented by local quantitative regulation at heating points; the latter is most common for hot water supply and is usually carried out automatically. In steam heat supply systems, local quantitative regulation is mainly carried out; The steam pressure in the heat supply source is maintained constant, the steam flow is regulated by consumers.

1.1 Composition of the heating system

The heat supply system consists of the following functional parts:

1) source of thermal energy production (boiler house, thermal power plant, solar collector, devices for recycling industrial thermal waste, installations for using heat from geothermal sources);

2) transporting devices of thermal energy to premises (heating networks);

3) heat-consuming devices that transfer thermal energy to the consumer (heating radiators, air heaters).

1.2 Classification of heat supply systems

Based on the location of heat generation, heat supply systems are divided into:

1) centralized (the source of thermal energy production works to supply heat to a group of buildings and is connected by transport devices to heat consumption devices);

2) local (the consumer and the heat supply source are in the same room or in close proximity).

The main advantages of centralized heat supply over local heat supply are a significant reduction in fuel consumption and operating costs (for example, due to the automation of boiler plants and increasing their efficiency); possibility of using low-grade fuel; reducing air pollution and improving the sanitary condition of populated areas. In local heat supply systems, heat sources include stoves, hot water boilers, water heaters (including solar), etc.

Based on the type of coolant, heat supply systems are divided into:

1) water (with temperatures up to 150 °C);

2) steam (under pressure 7-16 at).

Water serves mainly to cover municipal and household loads, and steam - technological loads. The choice of temperature and pressure in heat supply systems is determined by consumer requirements and economic considerations. With an increase in the distance of heat transportation, an economically justified increase in coolant parameters increases.

According to the method of connecting the heating system to the heat supply system, the latter are divided into:

1) dependent (coolant heated in a heat generator and transported through heating networks goes directly to heat-consuming devices);

2) independent (the coolant circulating through the heating networks in the heat exchanger heats the coolant circulating in the heating system). (Fig.1)

In independent systems, consumer installations are hydraulically isolated from the heating network. Such systems are used mainly in large cities - in order to increase the reliability of heat supply, as well as in cases where the pressure regime in the heating network is unacceptable for heat-consuming installations due to the conditions of their strength, or when the static pressure created by the latter is unacceptable for the heating network ( such as, for example, heating systems of high-rise buildings).

Figure 1 – Schematic diagrams of heat supply systems according to the method of connecting heating systems to them

According to the method of connecting the hot water supply system to the heating system:

1) closed;

2) open.

In closed systems, the hot water supply is supplied with water from the water supply system, heated to the required temperature by water from the heating network in heat exchangers installed at heating points. IN open systems water is supplied directly from the heating network (direct water supply). Water leakage due to leaks in the system, as well as its consumption for water collection, are compensated by additional supply of the corresponding amount of water to the heating network. To prevent corrosion and scale formation on the inner surface of the pipeline, water supplied to the heating network undergoes water treatment and deaeration. In open systems, the water must also meet drinking water requirements. The choice of system is determined mainly by the availability of a sufficient amount of potable water, its corrosive and scale-forming properties. Both types of systems have become widespread in Ukraine.

Based on the number of pipelines used to transfer coolant, heat supply systems are distinguished:

single-pipe;

two-pipe;

multi-pipe.

Single-pipe systems are used in cases where the coolant is completely used by consumers and is not returned (for example, in steam systems without condensate return and in open water systems, where all the water coming from the source is disassembled for hot water supply to consumers).

In two-pipe systems, the coolant is completely or partially returned to the heat source, where it is heated and replenished.

Multi-pipe systems are suitable when it is necessary to allocate certain types of heat load (for example, hot water supply), which simplifies the regulation of heat supply, operating mode and methods of connecting consumers to heating networks. In Russia, two-pipe heat supply systems have become prevalent.

1.3 Types of heat consumers

Heat consumers of the heating supply system are:

1) heat-using sanitary systems of buildings (heating, ventilation, air conditioning, hot water supply systems);

2) technological installations.

Using heated water for space heating is quite common. In this case, a variety of methods of transferring water energy are used to create a comfortable indoor environment. One of the most common is the use of heating radiators.

An alternative to heating radiators is underfloor heating, where the heating circuits are located under the floor. The floor heating circuit is usually connected to the radiator circuit.

Ventilation - a fan coil unit that supplies hot air to a room, usually used in public buildings. Often a combination of heating devices is used, for example, heating and floor heating radiators or heating and ventilation radiators.

Hot tap water has become part of everyday life and daily needs. Therefore, the hot water installation must be reliable, hygienic and economical.

Based on heat consumption patterns throughout the year, two groups of consumers are distinguished:

1) seasonal, requiring heat only during the cold season (for example, heating systems);

2) year-round, requiring heat all year round (hot water supply systems).

Depending on the ratio and modes of individual types of heat consumption, three characteristic groups of consumers are distinguished:

1) residential buildings (characterized by seasonal heat consumption for heating and ventilation and year-round heat consumption for hot water supply);

2) public buildings (seasonal heat consumption for heating, ventilation and air conditioning);

3) industrial buildings and structures, including agricultural complexes (all types of heat consumption, the quantitative relationship between which is determined by the type of production).

2 District heating

District heating is an environmentally friendly and reliable way to provide heat. District heating systems distribute hot water, or in some cases steam, from a central boiler room among numerous buildings. There is a very wide range of sources used to produce heat, including burning oil and natural gas or using geothermal waters. The use of heat from low-temperature sources, such as geothermal heat, is possible through the use of heat exchangers and heat pumps. The possibility of using non-recovered heat from industrial enterprises, excess heat from waste processing, industrial processes and sewerage, target heating plants or thermal power plants in district heating, allows for the optimal choice of heat source in terms of energy efficiency. This way you optimize costs and protect the environment.

Hot water from the boiler room is supplied to a heat exchanger that separates the production site from the distribution pipes of the district heating network. The heat is then distributed among end users and supplied to the relevant buildings through substations. Each of these substations usually includes one heat exchanger for space heating and hot water supply.

There are several reasons for installing heat exchangers to separate the heating plant and the district heating network. Where there are significant differences in pressure and temperature that can cause serious damage to equipment and property, a heat exchanger can keep sensitive heating and ventilation equipment from being exposed to contaminated or corrosive fluids. Another important reason for separating the boiler plant, distribution network and end users is to clearly define the functions of each system component.

In a combined heat and power plant (CHP), heat and electricity are produced simultaneously, with heat as a by-product. The heat is typically used in district heating systems, leading to increased energy efficiency and cost savings. The degree of use of energy obtained from fuel combustion will be 85–90%. Efficiency will be 35–40% higher than in the case of separate production of heat and electricity.

In a thermal power plant, burning fuel heats up water, which turns into steam. high pressure and high temperature. The steam drives a turbine connected to a generator that produces electricity. After the turbine, the steam condenses in a heat exchanger. The heat generated by this process is then fed into district heating pipes and distributed to end users.

For the end consumer, centralized heat supply means uninterrupted energy supply. A district heating system is more convenient and efficient than small individual home heating systems. Modern technologies combustion of fuel and purification of emissions reduce the negative impact on the environment.

In apartment buildings or other buildings heated by central heating units, the main requirement is heating, hot water supply, ventilation and underfloor heating for a large number of consumers with minimal energy consumption. Using high-quality equipment in the heating system, you can reduce overall costs.

Another very important task of heat exchangers in district heating is to ensure safety internal system by separating end consumers from the distribution network. This is necessary due to the significant difference in temperature and pressure. In the event of an accident, the risk of flooding can also be minimized.

In central heating points, a two-stage scheme for connecting heat exchangers is often found (Fig. 2, A). This connection means maximum heat utilization and low return water temperature when using a hot water system. It is particularly advantageous in combined heat and power (CHP) applications where low return water temperatures are desired. This type of substation can easily supply heat to up to 500 apartments, and sometimes more.

A) Two-stage connection B) Parallel connection

Figure 2 – Heat exchanger connection diagram

Parallel connection of a DHW heat exchanger (Fig. 2, B) is less complicated than a two-stage connection and can be used for any installation size that does not require low return water temperatures. This connection is usually used for small and medium-sized heating points with a load of up to approximately 120 kW. Connection diagram for hot water supply water heaters in accordance with SP 41-101-95.

Most district heating systems place high demands on the installed equipment. The equipment must be reliable and flexible, providing the necessary security. In some systems it must also meet very high hygiene standards. Another important factor in most systems is low operating costs.

However, in our country the centralized heating system is in a deplorable state:

the technical equipment and level of technological solutions in the construction of heating networks correspond to the state of the 1960s, while the radii of heat supply have sharply increased and there has been a transition to new standard sizes of pipe diameters;

the quality of metal of heat pipes, thermal insulation, shut-off and control valves, designs and laying of heat pipes is significantly inferior to foreign analogues, which leads to large losses of thermal energy in networks;

poor conditions for thermal and waterproofing of heating pipelines and heating network channels contributed to increased damage to underground heating pipelines, which led to serious problems in replacing heating network equipment;

domestic equipment of large CHPPs corresponds to the average foreign level of the 1980s, and currently steam turbine CHPPs are characterized by a high accident rate, since almost half of the installed turbine capacity has reached its design life;

at existing coal-fired thermal power plants there are no systems for cleaning flue gases from NOx and SOx, and the efficiency of collecting solid particles often does not reach the required values;

competitiveness of the central heating system modern stage can only be ensured by introducing specially new technical solutions, both in the structure of systems and in diagrams and equipment of energy sources and heating networks.

2.2 Efficiency of district heating systems

One of the most important conditions for the normal operation of the heat supply system is the creation of a hydraulic mode that ensures pressure in the heating network sufficient to create network water flows in heat-consuming installations in accordance with the given heat load. The normal operation of heat consumption systems is the provision of consumers with thermal energy of appropriate quality, and for the energy supplying organization it is to maintain the parameters of the heat supply regime at the level regulated by the Rules Technical Operation(PTE) of power plants and networks of the Russian Federation, PTE of thermal power plants. The hydraulic mode is determined by the characteristics of the main elements of the heating system.

During operation in the existing centralized heat supply system, due to changes in the nature of the heat load, connection of new heat consumers, increase in the roughness of pipelines, adjustment of the design temperature for heating, changes in the temperature schedule for the release of thermal energy (TE) from the TE source, as a rule, uneven heat supply occurs consumers, overestimation of network water costs and reduction in pipeline capacity.

In addition to this, there are usually problems in heat consumption systems. Such as misregulation of heat consumption modes, understaffing of elevator units, unauthorized violation by consumers of connection schemes (established by projects, technical conditions and contracts). These problems of heat consumption systems manifest themselves, first of all, in the misalignment of the entire system, characterized by increased coolant costs. As a consequence, there are insufficient (due to increased pressure losses) available coolant pressures at the inlets, which in turn leads to the desire of subscribers to provide the necessary drop by draining network water from the return pipelines to create at least minimal circulation in heating devices (violations of connection diagrams and etc.), which leads to an additional increase in flow rate and, consequently, to additional pressure losses, and to the emergence of new subscribers with reduced pressure drops, etc. A “chain reaction” occurs in the direction of a total misalignment of the system.

All this has Negative influence on the entire heat supply system and on the activities of the energy supply organization: inability to comply with the temperature schedule; increased replenishment of the heat supply system, and if the water treatment capacity is exhausted, forced replenishment raw water(consequence – internal corrosion, premature failure of pipelines and equipment); forced increase in heat supply to reduce the number of complaints from the population; increase in operating costs in the system of transport and distribution of thermal energy.

It is necessary to point out that in a heat supply system there is always a relationship between established thermal and hydraulic regimes. A change in flow distribution (its absolute value inclusive) always changes the condition of heat exchange, both directly in heating installations and in heat consumption systems. The result of abnormal operation of the heating system is, as a rule, a high temperature of the return network water.

It should be noted that the temperature of the return network water at the source of thermal energy is one of the main operating characteristics intended to analyze the condition of the equipment of heating networks and operating modes of the heat supply system, as well as to assess the effectiveness of measures taken by organizations operating heating networks in order to increase the level operation of the heating system. As a rule, in the event of misadjustment of the heat supply system, the actual value of this temperature differs significantly from its standard, calculated value for a given heat supply system.

Thus, when the heat supply system is deregulated, the temperature of the network water, as one of the main indicators of the mode of supply and consumption of thermal energy in the heat supply system, turns out to be: in the supply pipeline in almost all intervals of the heating season is characterized by reduced values; the temperature of the return network water, despite this, is characterized by increased values; the temperature difference in the supply and return pipelines, namely this indicator (along with the specific consumption of network water per connected heat load) characterizes the level of quality of thermal energy consumption, is underestimated compared to the required values.

One more aspect should be noted, related to the increase relative to the calculated value of the flow of network water for the thermal regime of heat consumption systems (heating, ventilation). For direct analysis, it is advisable to use the dependence, which determines, in case of deviation of the actual parameters and structural elements of the heat supply system from the calculated ones, the ratio of the actual consumption of thermal energy in heat consumption systems to its calculated value.

where Q is the consumption of thermal energy in heat consumption systems;

g- flow of network water;

tп and to - temperature in the supply and return pipelines.

This dependence (*) is shown in Fig. 3. The ordinate axis shows the ratio of the actual consumption of thermal energy to its calculated value, and the abscissa axis shows the ratio of the actual consumption of network water to its calculated value.

Figure 3 – Graph of the dependence of thermal energy consumption by systems

heat consumption from network water consumption.

As general trends, it is necessary to indicate that, firstly, an increase in the consumption of network water by n times does not cause an increase in thermal energy consumption corresponding to this number, that is, the coefficient of heat consumption lags behind the coefficient of consumption of network water. Secondly, when the flow of network water decreases, the heat supply to the local heat consumption system decreases the faster, the lower the actual consumption of network water is compared to the calculated one.

Thus, heating and ventilation systems react very poorly to excessive consumption of network water. Thus, an increase in the flow of network water for these systems relative to the calculated value by 50% causes an increase in heat consumption by only 10%.

The point in Fig. 3 with coordinates (1;1) displays the calculated, actually achievable operating mode of the heat supply system after commissioning activities. By actually achievable operating mode is meant a mode that is characterized by the existing position of the structural elements of the heat supply system, heat losses by buildings and structures, and the determined total flow of network water at the terminals of the thermal energy source necessary to provide a given heat load under the existing schedule of thermal energy supply.

It should also be noted that the increased consumption of network water, due to the limited throughput of heating networks, leads to a decrease in the available pressure values ​​at the consumer inputs necessary for the normal operation of heat-consuming equipment. It should be noted that pressure losses through the heating network are determined by a quadratic dependence on the flow of network water:

That is, with an increase in the actual flow rate of network water GF by 2 times relative to the calculated value GP, pressure losses through the heating network increase 4 times, which can lead to unacceptably low available pressures at the thermal nodes of consumers and, consequently, to insufficient heat supply to these consumers, which may cause unauthorized drainage of network water to create circulation (unauthorized violation by consumers of connection diagrams, etc.)

Further development of such a heat supply system along the path of increasing coolant flow, firstly, will require replacing the head sections of heat pipelines, additional installation of network pumping units, increasing water treatment productivity, etc., and secondly, leads to an even greater increase in additional costs - expenses for compensation for electricity, make-up water, thermal energy losses.

Thus, it seems technically and economically more feasible to develop such a system by improving its quality indicators - increasing the temperature of the coolant, pressure drops, increasing the temperature difference (heat removal), which is impossible without a drastic reduction in coolant costs (circulation and make-up) in heat consumption systems and , respectively, throughout the entire heat supply system.

Thus, the main measure that can be proposed to optimize such a heat supply system is the adjustment of the hydraulic and thermal conditions of the heat supply system. The technical essence of this event is to establish flow distribution in the heat supply system based on the calculated (i.e. corresponding to the connected heat load and the selected temperature schedule) network water flow rates for each heat consumption system. This is achieved by installing appropriate throttling devices (auto-regulators, throttling washers, elevator nozzles) at the inputs to heat consumption systems, which are calculated based on the calculated pressure drop at each input, which is calculated based on the hydraulic and thermal calculations of the entire heat supply system.

It should be noted that the creation of a normal mode of operation of such a heat supply system is not limited only to carrying out adjustment activities; it is also necessary to carry out work to optimize the hydraulic mode of the heat supply system.

Regime adjustment covers the main parts of the centralized heat supply system: water heating installation of the heat source, central heating points (if any), heating network, control and distribution points (if available), individual heating points and local heat consumption systems.

The setup begins with an inspection of the centralized heating system. The collection and analysis of initial data on the actual operating modes of the transport and distribution of thermal energy system, information on technical condition heating networks, the degree of equipment of the heat source, heating networks and subscribers with commercial and technological means measurements. The applied heat supply modes are analyzed, possible design and installation defects are identified, and information is selected to analyze the characteristics of the system. An analysis of operational (statistical) information (records of coolant parameters, modes of supply and energy consumption, actual hydraulic and thermal modes of heating networks) is carried out at various values ​​of outdoor air temperature in base periods, obtained from the readings of standard measuring instruments, and an analysis of reports from specialized organizations is also carried out. .

In parallel, a design diagram of heating networks is being developed. A mathematical model of the heat supply system is being created on the basis of the ZuluThermo calculation complex, developed by Politerm (St. Petersburg), capable of simulating the actual thermal and hydraulic operating conditions of the heat supply system.

It is necessary to point out that there is a fairly common approach, which consists in minimizing the financial costs associated with the development of measures for setting up and optimizing the heat supply system, namely, costs are limited to the acquisition of a specialized software package.

The pitfall with this approach is the reliability of the source data. A mathematical model of a heat supply system, created on the basis of unreliable initial data on the characteristics of the main elements of the heat supply system, turns out, as a rule, to be inadequate to reality.

2.3 Energy saving in district heating systems

Recently, there have been criticisms about centralized heat supply based on district heating - the joint production of thermal and electrical energy. The main disadvantages include large heat losses in pipelines during heat transport, and a decrease in the quality of heat supply due to non-compliance with the temperature schedule and required pressures at consumers. It is proposed to switch to decentralized, autonomous heat supply from automated boiler houses, including those located on the roofs of buildings, justifying this by lower cost and the absence of the need to lay heat pipelines. But at the same time, as a rule, it is not taken into account that connecting the heat load to the boiler room makes it impossible to generate cheap electricity from heat consumption. Therefore, this part of ungenerated electricity must be replaced by its production through the condensation cycle, the efficiency of which is 2-2.5 times lower than that of the cogeneration cycle. Consequently, the cost of electricity consumed by a building, the heat supply of which is provided from the boiler house, should be higher than that of a building connected to a district heating system, and this will cause a sharp increase in operating costs.

S. A. Chistovich at the anniversary conference “75 years of district heating in Russia”, held in Moscow in November 1999, proposed that house boiler houses complement centralized heat supply, acting as peak heat sources, where the lack of network capacity does not allow for high-quality supply heat of consumers. At the same time, district heating is preserved and the quality of heat supply is improved, but this decision reeks of stagnation and hopelessness. It is necessary that the centralized heating supply fully fulfill its functions. After all, district heating has its own powerful peak boiler houses, and it is obvious that one such boiler house will be more economical than hundreds of small ones, and if the network capacity is insufficient, then it is necessary to shift the networks or cut off this load from the networks so that it does not disturb the quality of heat supply to other consumers.

Denmark has achieved great success in district heating; despite the low concentration of heat load per 1 m2 of surface area, it is ahead of us in district heating coverage per capita. In Denmark, a special government policy is being pursued to prefer connecting new heat consumers to centralized heat supply. In Western Germany, for example in the city of Mannheim, district heating based on district heating is developing rapidly. IN Eastern lands, where, focusing on our country, district heating was also widely used, despite the abandonment of panel housing construction, central heating stations in residential neighborhoods, which turned out to be ineffective in a market economy and Western way of life, the area of ​​centralized heating based on district heating continues to develop as the most environmentally friendly and economically beneficial.

All of the above indicates that at the new stage we must not lose our leading position in the field of district heating, and for this it is necessary to modernize the centralized heating system in order to increase its attractiveness and efficiency.

All the advantages of the joint production of heat and electrical energy were attributed to the electricity side; centralized heat supply was financed on a residual basis - sometimes a thermal power plant had already been built, but the heating networks had not yet been connected. As a result, low-quality heat pipelines were created with poor insulation and ineffective drainage; heat consumers were connected to heating networks without automatic regulation load, at best using hydraulic regulators for stabilizing coolant flow of very low quality.

This forced heat supply from the source using the method of central quality control (by changing the temperature of the coolant depending on outside temperature according to a single schedule for all consumers with constant circulation in the networks), which led to a significant overconsumption of heat by consumers due to differences in their operating modes and the impossibility of several heat sources working together on a single network to implement mutual backup. The absence or ineffectiveness of control devices at the points where consumers are connected to heating networks also caused excessive consumption of the coolant volume. This led to an increase in the temperature of the return water to such an extent that there was a danger of failure of the station circulation pumps and this forced a reduction in heat supply at the source, violating the temperature schedule even under conditions of sufficient power.

Unlike us, in Denmark, for example, all the benefits of district heating in the first 12 years are transferred to the thermal energy side, and then divided in half with electrical energy. As a result, Denmark was the first country to produce pre-insulated ductless pipes with a sealed cover layer and an automatic leak detection system, which dramatically reduced heat loss during transport. In Denmark, silent, supportless “wet running” circulation pumps, heat metering devices and effective automatic heat load control systems were invented for the first time, which made it possible to construct automated individual heating points (IHP) directly in consumers’ buildings with automatic regulation of heat supply and metering in places where it is used. use.

Complete automation of all heat consumers made it possible to: abandon the high-quality method of central regulation at the heat source, which causes unwanted temperature fluctuations in the pipelines of the heating network; reduce the maximum water temperature parameters to 110-1200C; to ensure the ability to operate several heat sources, including waste incineration plants, on a single network with the most efficient use of each.

The water temperature in the supply pipeline of heating networks changes depending on the level of the established outside air temperature in three steps: 120-100-80°C or 100-85-70°C (there is a tendency for this temperature to decrease even more). And inside each stage, depending on the change in load or deviation in the outside temperature, the flow rate of the coolant circulating in the heating networks changes according to the signal of the fixed value of the pressure difference between the supply and return pipelines - if the pressure difference drops below a predetermined value, then subsequent heat generating and pumping stations are turned on at the stations installations. Heat supply companies guarantee each consumer a specified minimum level of pressure drop in the supply networks.

Consumers are connected through heat exchangers, and, in our opinion, an excessive number of connection stages are used, which is apparently caused by property boundaries. Thus, the following connection scheme was demonstrated: to the main networks with design parameters of 125°C, which are managed by the energy producer, through a heat exchanger, after which the water temperature in the supply pipeline is reduced to 120°C, distribution networks that are in municipal ownership are connected.

The level of maintaining this temperature is set by an electronic regulator acting on a valve installed on the return pipeline of the primary circuit. In the secondary circuit, coolant circulation is carried out by pumps. Connection of local heating and hot water supply systems of individual buildings to these distribution networks is carried out through independent heat exchangers installed in the basements of these buildings with a full set of heat regulation and metering devices. Moreover, the temperature of the water circulating in the local heating system is regulated according to a schedule depending on changes in the outside air temperature. Under design conditions, the maximum water temperature reaches 95°C, recently there has been a tendency to reduce it to 75-70°C, the maximum return water temperature is 70 and 50°C, respectively.

Connection of heating points of individual buildings is carried out according to standard schemes with parallel connection of a hot water supply tank water heater or according to a two-stage scheme using the potential of the coolant from the return pipeline after the heating water heater using high-speed hot water supply heat exchangers, while it is possible to use a pressure hot water storage tank with a pump for charging the tank. In the heating circuit, pressure membrane tanks are used to collect water as it expands from heating; in our country, atmospheric expansion tanks installed at the top point of the system are more commonly used.

To stabilize the operation of control valves, a hydraulic constant pressure differential regulator is usually installed at the inlet to the heating point. And to bring heating systems with pump circulation to optimal operating mode and facilitate the distribution of the coolant along the risers of the system - a “partner valve” in the form of a balance valve, which allows you to set the correct flow rate of the circulating coolant based on the pressure loss measured on it.

In Denmark, they do not pay much attention to the increase in the calculated coolant flow to the heating point when water heating is turned on for domestic needs. In Germany, it is legally prohibited to take into account the load on the hot water supply when selecting heat power, and when automating heating points, it is accepted that when the hot water supply water heater is turned on and when the storage tank is filled, the pumps that provide circulation in the heating system are turned off, i.e., the heat supply to the heating system is stopped. heating.

Our country also attaches great importance to preventing an increase in the power of the heat source and the calculated flow rate of the coolant circulating in the heating network during the hours of maximum hot water supply. But the solution adopted in Germany for this purpose cannot be applied in our conditions, since we have a much higher ratio of hot water supply and heating loads, due to the large absolute value of domestic water consumption and higher population density.

Therefore, when automating consumer heating points, a limitation is applied to the maximum water flow from the heating network when a set value is exceeded, determined based on the average hourly DHW load. When supplying heat to residential neighborhoods, this is done by closing the valve of the heat supply regulator for heating during hours of maximum water consumption. By setting the heating regulator to slightly overestimate the maintained coolant temperature schedule, the underheating in the heating system that occurs when the maximum watershed is passed is compensated for during periods of water withdrawal below average (within the limits of a given water flow from the heating network - related regulation).

The water flow sensor, which is a signal for limitation, is a water flow meter included in the heat meter kit installed at the heating network input to the central heating substation or ITP. The inlet pressure differential regulator cannot serve as a flow limiter, since it provides a given pressure differential under conditions of full opening of the heating and hot water supply regulator valves installed in parallel.

In order to increase the efficiency of the joint production of thermal and electrical energy and level out the maximum energy consumption, thermal accumulators that are installed at the source have been widely used in Denmark. The lower part of the battery is connected to the return pipeline of the heating network, the upper part is connected to the supply pipeline through a movable diffuser. When the circulation in the heating distribution networks decreases, the tank is charged. As circulation increases, excess coolant flow from the return pipeline enters the tank, and hot water is squeezed out of it. The need for heat accumulators increases in thermal power plants with back-pressure turbines, in which the ratio of generated electrical and thermal energy is fixed.

If the design temperature of the water circulating in the heating networks is below 100°C, then atmospheric storage tanks are used; at a higher design temperature, pressure is created in the tanks to ensure that hot water does not boil.

However, installing thermostats together with heat flow meters on each heating device leads to an almost double increase in the cost of the heating system, and in a single-pipe scheme, in addition, the required heating surface of the devices increases by up to 15% and there is a significant residual heat transfer of the devices in the closed position of the thermostat, which reduces the efficiency of autoregulation. Therefore, an alternative to such systems, especially in low-cost municipal construction, are facade automatic heating control systems - for extended buildings and central ones with correction of the temperature curve according to the deviation of the air temperature in the prefabricated ducts exhaust ventilation from apartment kitchens - for single-family buildings or buildings with complex configurations.

However, it must be borne in mind that when reconstructing existing residential buildings, in order to install thermostats, it is necessary to enter each apartment with welding. At the same time, when organizing façade-by-facade automatic regulation, it is enough to insert jumpers between the facade branches of sectional heating systems in the basement and attic, and for 9-story attic-free buildings of mass construction of the 60-70s - only in the basement.

It should be noted that new construction per year does not exceed 1-2% of the existing housing stock. This indicates how important the reconstruction of existing buildings is becoming in order to reduce heat costs for heating. However, it is impossible to automate all buildings at once, and in conditions when several buildings are automated, real savings are not achieved, since the coolant saved on automated objects is redistributed among non-automated ones. The above once again confirms that it is necessary to build PSCs on existing heating networks at an accelerated pace, since it is much easier to simultaneously automate all buildings powered by one PSC than from a thermal power plant, and other already created PSCs will not allow excess coolant into their distribution networks.

All of the above does not exclude the possibility of connecting individual buildings to boiler houses with an appropriate feasibility study with an increase in the tariff for consumed electricity (for example, when laying or relaying a large number of networks is necessary). But in the conditions of the existing system of centralized heat supply from thermal power plants, this should be local in nature. The possibility of using heat pumps and transferring part of the load to CCGTs and GTUs cannot be ruled out, but given the current price environment for fuel and energy resources, this is not always cost-effective.

Heat supply to residential buildings and neighborhoods in our country, as a rule, is carried out through group heating points (CHS), after which individual buildings are supplied through independent pipelines with hot water for heating and for domestic needs with tap water heated in heat exchangers installed in the CHS. Sometimes up to 8 heat pipelines leave the central heating station (with a 2-zone hot water supply system and the presence of a significant ventilation load), and although galvanized hot water supply pipelines are used, due to the lack of chemical water treatment they are subject to intense corrosion and after 3-5 years of operation on them fistulas appear.

Currently, due to the privatization of housing and service enterprises, as well as the rising cost of energy resources, the transition from group heating points to individual ones (IHP) located in a heated building is relevant. This makes it possible to use a more efficient façade-by-facade automatic heating control system for extended buildings or a central one with correction for internal air temperature in single-point buildings; it allows one to abandon hot water supply distribution networks, reducing heat losses during transportation and energy consumption for pumping domestic hot water. Moreover, it is advisable to do this not only in new construction, but also during the reconstruction of existing buildings. Such experience exists in the Eastern lands of Germany, where, just like ours, central heating stations were built, but now they are left only as pumping water supply stations (if necessary), and heat exchange equipment, along with circulation pumps, control and metering units, are transferred to the ITP of buildings . Intra-block networks are not laid, hot water supply pipelines are left in the ground, and heating pipelines, as they are more durable, are used to supply superheated water to buildings.

To improve the controllability of heat networks, to which a large number of ITPs will be connected, and to ensure the possibility of automatic backup, one should return to the construction of control and distribution points (CDP) at the points where distribution networks are connected to the main ones. Each distribution point is connected to the main line on both sides of sectional valves and serves consumers with a heat load of 50-100 MW. The control panel is equipped with switching electric valves at the inlet, pressure regulators, circulation and mixing pumps, a temperature controller, a safety valve, heat and coolant flow metering devices, control and telemechanics devices.

The automation circuit of the control valve ensures that the pressure is maintained at a constant minimum level in the return line; maintaining a constant specified pressure drop in the distribution network; reducing and maintaining the water temperature in the supply pipeline of the distribution network according to a given schedule. As a result, in backup mode, it is possible to supply a reduced amount of circulating water with an increased temperature through the mains from the thermal power plant without disturbing the temperature and hydraulic conditions in the distribution networks.

PSCs should be located in ground pavilions, they can be interlocked with water pumping stations (this will, in most cases, eliminate the installation of high-pressure and therefore noisier pumps in buildings), and can serve as the boundary of the balance sheet between the heat-distributing organization and the heat-distributing one (the next boundary between the heat-distributing and the heat-using organizations will be the wall of the building). Moreover, the distribution centers must be under the jurisdiction of the heat distributing organization, since they serve to manage and back up the main networks and provide the ability to operate several heat sources on these networks, taking into account the maintenance of the coolant parameters specified by the heat distribution organization at the exit from the distribution center.

Proper Use coolant on the heat consumer side is ensured by using efficient systems control automation. Nowadays there are a large number of computer systems that can perform control tasks of any complexity, but technological tasks and circuit solutions for connecting heat consumption systems remain decisive.

Recently, they have begun to build water heating systems with thermostats that carry out individual automatic regulation of the heat transfer of heating devices based on the air temperature in the room where the device is installed. Such systems are widely used abroad with the addition of mandatory measurement of the amount of heat used by the device as a proportion of the total heat consumption of the building's heating system.

In our country, in mass construction, such systems began to be used for elevator connection to heating networks. But the elevator is designed in such a way that, with a constant nozzle diameter and the same available pressure, it passes a constant flow of coolant through the nozzle, regardless of changes in the flow of water circulating in the heating system. As a result, in 2-pipe heating systems, in which the thermostats, when closed, lead to a reduction in the flow of coolant circulating in the system, with an elevator connection the water temperature in the supply pipeline will increase, and then in the return pipeline, which will lead to an increase in heat transfer from the unregulated part of the system (risers) and to underutilization of coolant.

In a single-pipe heating system with constantly operating closing sections, when the thermostats are closed, hot water is discharged into the riser without cooling, which also leads to an increase in the temperature of the water in the return pipeline and, due to the constancy of the mixing coefficient in the elevator, to a rise in the temperature of the water in the supply pipeline, and therefore to the same consequences as in a 2-pipe system. Therefore, in such systems it is mandatory to automatically regulate the water temperature in the supply pipeline according to a schedule depending on changes in the outside air temperature. Such regulation is possible by changing the circuit solution for connecting the heating system to the heating network: replacing a conventional elevator with an adjustable one, by using pump mixing with a control valve, or by connecting through a heat exchanger with pump circulation and a control valve on network water in front of the heat exchanger. [

3 DECENTRALIZED HEAT SUPPLY

3.1 Prospects for the development of decentralized heat supply

Previously made decisions to close small boiler houses (under the pretext of their low efficiency, technical and environmental dangers) today have turned into over-centralization of heat supply, when hot water travels 25-30 km from the thermal power plant to the consumer, when the heat source is turned off due to non-payment or emergency situation leads to freezing of cities with a million people.

Most industrialized countries followed a different path: they improved heat-generating equipment, increasing the level of its safety and automation, the efficiency of gas burners, sanitary, environmental, ergonomic and aesthetic indicators; created a comprehensive system for accounting for energy resources by all consumers; brought the regulatory and technical framework into line with the requirements of expediency and consumer convenience; optimized the level of centralization of heat supply; switched to the widespread introduction of alternative sources of thermal energy. The result of this work was real energy saving in all areas of the economy, including housing and communal services.

A gradual increase in the share of decentralized heat supply, bringing the heat source as close as possible to the consumer, and accounting by the consumer of all types of energy resources will not only create more comfortable conditions for the consumer, but also ensure real savings in gas fuel.

A modern decentralized heat supply system is a complex set of functionally interconnected equipment, including an autonomous heat generating unit and building engineering systems (hot water supply, heating and ventilation systems). The main elements of an apartment heating system, which is a type of decentralized heat supply in which each apartment in an apartment building is equipped with an autonomous system for providing heat and hot water, are a heating boiler, heating devices, air supply and combustion product removal systems. The wiring is carried out using a steel pipe or modern heat-conducting systems - plastic or metal-plastic.

The system of centralized heat supply, traditional for our country, through thermal power plants and main heat pipelines, is well known and has a number of advantages. But in the conditions of transition to new economic mechanisms, known economic instability and weakness of interregional, interdepartmental relations, many of the advantages of the centralized heat supply system turn into disadvantages.

The main one is the length of heating mains. The average percentage of wear is estimated at 60-70%. The specific damage rate of heating pipelines has currently increased to 200 registered damages per year per 100 km of heating networks. According to emergency estimates, at least 15% of heating networks require immediate replacement. In addition to this, over the past 10 years, as a result of underfinancing, the industry's fixed assets have practically not been updated. As a result, heat energy losses during production, transportation and consumption reached 70%, which led to poor quality of heat supply at high costs.

Organizational structure interaction between consumers and heat supply companies does not stimulate the latter to save energy resources. The system of tariffs and subsidies does not reflect the real costs of heat supply.

In general, the critical situation in which the industry finds itself suggests the emergence of a large-scale crisis in the heat supply sector in the near future, the resolution of which will require colossal financial investments.

The pressing issue is reasonable decentralization of heat supply, apartment-by-apartment heat supply. Decentralization of heat supply (DH) is the most radical, effective and cheapest way to eliminate many shortcomings. Justified use of DT in combination with energy saving measures during the construction and reconstruction of buildings will provide great savings in energy resources in Ukraine. In the current difficult conditions, the only way out is the creation and development of a diesel fuel system through the use of autonomous heat sources.

Apartment heating is the autonomous provision of heat and hot water to an individual house or a separate apartment in a multi-storey building. The main elements of such autonomous systems is: heat generators - heating devices, heating and hot water supply pipelines, fuel supply, air and smoke removal systems.

The objective prerequisites for the implementation of autonomous (decentralized) heat supply systems are:

the absence in some cases of free capacity at centralized sources;

densification of urban areas with housing facilities;

in addition, a significant part of the development is located in areas with undeveloped engineering infrastructure;

lower capital investments and the ability to gradually cover thermal loads;

the ability to maintain comfortable conditions in the apartment at your own request, which in turn is more attractive compared to apartments with centralized heat supply, the temperature in which depends on the directive decision on the beginning and end of the heating period;

the appearance on the market of a large number of different modifications of domestic and imported (foreign) low-power heat generators.

Today, modular boiler units designed for organizing autonomous diesel fuel have been developed and are being mass-produced. The block-modular construction principle makes it possible to simply build a boiler house of the required power. The absence of the need to lay heating mains and construct a boiler house building reduces the cost of communications and makes it possible to significantly increase the pace of new construction. In addition, this makes it possible to use such boiler houses for prompt provision of heat supply in emergency and emergency situations during the heating season.

Block boiler rooms are a fully functionally complete product, equipped with all the necessary automation and safety devices. Automation level provides uninterrupted operation of all equipment without the constant presence of an operator.

Automation monitors the facility’s need for heat depending on weather conditions and independently regulates the operation of all systems to ensure the specified modes. This achieves better compliance with the thermal schedule and additional fuel savings. In case of emergency situations, gas leaks, the security system automatically stops the gas supply and prevents the possibility of accidents.

Many enterprises, having adjusted to today's conditions and having calculated the economic benefits, are moving away from centralized heating supply and from remote and energy-intensive boiler houses.

The advantages of decentralized heat supply are:

no need for land allocation for heating networks and boiler houses;

reduction of heat losses due to the lack of external heating networks, reduction of network water losses, reduction of water treatment costs;

significant reduction in costs for equipment repair and maintenance;

full automation of consumption modes.

If we take into account the lack of autonomous heating from small boiler houses and relatively low chimneys and the resulting environmental damage, then a significant reduction in gas consumption associated with the dismantling of the old boiler house also reduces emissions by 7 times!

Despite all the advantages, decentralized heat supply also has negative sides. In small boiler houses, including “roof” ones, the height of the chimneys, as a rule, is much lower than in large ones, due to the sharply worsening dispersion conditions. In addition, small boiler houses are usually located near residential areas.

The introduction of programs for decentralization of heat sources makes it possible to halve the need for natural gas and several times reduce the cost of heat supply to end consumers. The principles of energy saving embedded in the current heat supply system of Ukrainian cities stimulate the emergence of new technologies and approaches that can solve this problem fully, and the economic efficiency of diesel fuel makes this area very attractive for investment.

The use of apartment-by-apartment heat supply systems for multi-storey residential buildings makes it possible to completely eliminate heat losses in heating networks and during distribution between consumers, and to significantly reduce losses at the source. Allows you to organize individual accounting and regulation of heat consumption depending on economic capabilities and physiological needs. Apartment-by-apartment heat supply will lead to a reduction in one-time capital investments and operating costs, and also allows saving energy and raw materials for the production of thermal energy and, as a consequence, leads to a reduction in the load on the environmental situation.

An apartment-by-apartment heat supply system is an economically, energetically and environmentally effective solution to the issue of heat supply for multi-storey buildings. And yet, it is necessary to conduct a comprehensive analysis of the effectiveness of using a particular heat supply system, taking into account many factors.

Thus, analysis of the components of losses during autonomous heat supply allows:

1) for the existing housing stock, increase the energy efficiency coefficient of heat supply to 0.67 versus 0.3 for centralized heat supply;

2) for new construction, only by increasing the thermal resistance of enclosing structures, increase the energy efficiency coefficient of heat supply to 0.77 versus 0.45 for centralized heat supply;

3) when using the entire complex of energy-saving technologies, increase the coefficient to 0.85 versus 0.66 with centralized heat supply.

3.2 Energy efficient solutions for diesel fuel

With autonomous heat supply, it is possible to use new technical and technological solutions that make it possible to completely eliminate or significantly reduce all unproductive losses in the chain of heat generation, transportation, distribution and consumption, and not just by building a mini-boiler house, but by using new energy-saving and efficient technologies, such How:

1) transition to a fundamentally new system of quantitative regulation of heat production and supply at the source;

2) effective use of variable frequency electric drives on all pumping units;

3) reducing the length of circulation heating networks and reducing their diameter;

4) refusal to build central heating points;

5) transition to a fundamentally new scheme of individual heating points with quantitative and qualitative regulation depending on the current outside air temperature using multi-speed mixing pumps and three-way regulator valves;

6) installation of a “floating” hydraulic mode of the heating network and complete rejection of hydraulic linkage of consumers connected to the network;

7) installation of control thermostats on apartment heating devices;

8) apartment-by-apartment wiring of heating systems with the installation of individual heat consumption meters;

9) automatic maintenance of constant pressure on hot water supply devices for consumers.

The implementation of these technologies allows, first of all, to minimize all losses and creates conditions for the coincidence in time of the regimes of the amount of generated and consumed heat.

3.3 Benefits of decentralized heating

If we trace the entire chain: source-transport-distribution-consumer, we can note the following:

1 Heat source - land allocation is significantly reduced, the construction part is cheaper (no foundations are required for equipment). The installed power of the source can be chosen to be almost equal to the consumed one, while it is possible not to take into account the load of hot water supply, since during peak hours it is compensated by the storage capacity of the consumer’s building. Today it is a reserve. The regulation scheme is simplified and made cheaper. Heat losses are eliminated due to the discrepancy between production and consumption modes, the correspondence of which is established automatically. In practice, only losses associated with the efficiency of the boiler unit remain. Thus, it is possible to reduce losses at the source by more than 3 times.

2 Heating networks - the length is reduced, the diameters are reduced, the network becomes more maintainable. Constant temperature regime increases the corrosion resistance of pipe materials. The amount of circulating water and its losses through leaks are reduced. There is no need to construct a complex water treatment scheme. There is no need to maintain a guaranteed pressure drop before connecting the consumer, and therefore there is no need to take measures for hydraulic linking of the heating network, since these parameters are set automatically. Experts imagine what a difficult problem it is to annually carry out hydraulic calculations and carry out work on hydraulic connection of an extensive heating network. Thus, losses in heating networks are reduced by almost an order of magnitude, and in the case of installing a rooftop boiler room for one consumer, these losses are absent at all.

3 Distribution systems central heating and heating substations. Required

Ministry of Education and Science

State Educational Institution of Higher Professional Education "Brotherly" State University»

Faculty of Energy and Automation

Department of Industrial Thermal Power Engineering

Abstract on the discipline

"Heat and ventilation"

Modern heating systems

Development prospects

Performed:

ST group TGV-08

ON THE. Snegireva

Supervisor:

Professor, Ph.D., Department of PTE

S.A. Semenov

Bratsk 2010

Introduction

1. Types of central heating systems and principles of their operation

4.2 Gas heating

4.3 Air heating

4.4 Electric heating

4.5 Pipelines

4.6 Boiler equipment

5. Prospects for the development of heat supply in Russia

Conclusion

List of used literature

Introduction

Living in temperate latitudes, where most of the year is cold, it is necessary to ensure heat supply to buildings: residential buildings, offices and other premises. Heat supply is provided comfortable accommodation, if it’s an apartment or a house, productive work if it’s an office or warehouse.

First, let’s figure out what is meant by the term “Heat supply”. Heat supply is the supply of hot water or steam to the heating systems of a building. The usual sources of heat supply are thermal power plants and boiler houses. There are two types of heat supply to buildings: centralized and local. With centralized supply, individual areas (industrial or residential) are supplied. For efficient work centralized heating network, it is built by dividing it into levels, the work of each element is to perform one task. With each level, the element's task decreases. Local heat supply is the supply of heat to one or more houses. Centralized heating networks have a number of advantages: reduction of fuel consumption and cost reduction, use of low-grade fuel, improvement of the sanitary condition of residential areas. The centralized heat supply system includes a source of thermal energy (CHP), a heating network and heat-consuming units. CHP plants combine to produce heat and energy. Sources of local heat supply are stoves, boilers, water heaters.

Heat supply systems differ in different temperatures and water pressure. This depends on customer requirements and economic considerations. As the distance over which heat must be “transferred” increases, economic costs increase. Currently, heat transfer distances are measured in tens of kilometers. Heat supply systems are divided according to the volume of heat loads. Heating systems are classified as seasonal, and hot water supply systems are classified as permanent.

1. Types of central heating systems and principles of their operation

District heating consists of three interconnected and sequential stages: preparation, transportation and use of the coolant. In accordance with these stages, each system consists of three main links: a heat source (for example, a combined heat and power plant or boiler house), heat networks (heat pipelines) and heat consumers.

In decentralized heat supply systems, each consumer has its own heat source.

Coolants in central heating systems can be water, steam and air; the corresponding systems are called water, steam or air heating systems. Each of them has its own advantages and disadvantages. heat supply central heating

The advantages of a steam heating system are its significantly lower cost and metal consumption compared to other systems: when 1 kg of steam condenses, approximately 535 kcal are released, which is 15-20 times more than the amount of heat released when 1 kg of water cools in heating devices, and therefore steam pipelines have a significantly smaller diameter than pipelines for a water heating system. In steam heating systems, the surface area of ​​the heating devices is smaller. In rooms where people stay periodically (industrial and public buildings), a steam heating system will make it possible to produce heating intermittently and without the risk of freezing of the coolant with subsequent rupture of pipelines.

The disadvantages of the steam heating system are its low hygienic qualities: dust in the air burns on heating devices heated to 100°C or more; it is impossible to regulate the heat transfer of these devices and for most of the heating period the system must operate intermittently; the presence of the latter leads to significant fluctuations in air temperature in heated rooms. Therefore, steam heating systems are installed only in those buildings where people stay periodically - in bathhouses, laundries, shower pavilions, train stations and clubs.

Air heating systems consume little metal, and they can simultaneously ventilate the room while heating it. However, the cost of an air heating system for residential buildings is higher than other systems.

Water heating systems are more expensive and metal intensive compared to steam heating, but they have high sanitary and hygienic qualities, which ensure their widespread use. They are installed in all residential buildings more than two floors high, in public buildings and in most industrial buildings. Centralized regulation of the heat transfer of devices in this system is achieved by changing the temperature of the water entering them.

Water heating systems are distinguished by the method of moving water and design solutions.

Based on the method of moving water, systems with natural and mechanical (pumping) stimulation are distinguished. Water heating systems with natural impulse. The schematic diagram of such a system consists of a boiler (heat generator), a supply pipeline, heating devices, a return pipeline and an expansion vessel. The water heated in the boiler enters the heating devices, transfers part of its heat to them to compensate for heat losses through the external enclosures of the heated building, then returns to the boiler and then the water circulation is repeated. Its movement occurs under the influence of a natural impulse that arises in the system when heating water in the boiler.

The circulation pressure created during the operation of the system is spent on overcoming the resistance to the movement of water through the pipes (from friction of water against the walls of the pipes) and on local resistance (in bends, taps, valves, heating devices, boilers, tees, crosses, etc.) .

The higher the speed of water movement in the pipes, the greater the magnitude of these resistances (if the speed doubles, then the resistance quadruples, i.e., in a quadratic relationship). In systems with natural impulse in buildings of small number of floors, the magnitude of the effective pressure is small, and therefore high speeds of water movement in the pipes cannot be allowed in them; therefore, the pipe diameters must be large. The system may not be economically viable. Therefore, the use of natural circulation systems is allowed only for small buildings. The range of such systems should not exceed 30 m, and the value of k should be at least 3 m.

As the water in the system heats up, its volume increases. To accommodate this additional volume of water in heating systems, an expansion vessel 3 is provided; in systems with overhead wiring and natural impulse, it simultaneously serves to remove from them the air released from the water when it is heated in boilers.

Pump driven water heating systems. The heating system is always filled with water and the task of the pumps is to create the pressure necessary only to overcome the resistance to the movement of water. In such systems, natural and pumping drives operate simultaneously; total pressure for two-pipe systems with overhead distribution, kgf/m2 (Pa)

For economic reasons, it is usually taken in the amount of 5-10 kgf/m2 per 1 m (49-98 Pa/m).

The advantages of systems with pumping stimulation are reduced costs for pipelines (their diameter is smaller than in systems with natural stimulation) and the ability to supply heat to a number of buildings from one boiler room.

The devices of the described system, located on different floors of the building, operate under different conditions. The pressure p2, which ensures water circulation through the device on the second floor, is approximately twice as high as the pressure p1 for the device on the ground floor. At the same time, the total resistance of the pipeline ring passing through the boiler and the second floor appliance is approximately equal to the resistance of the ring passing through the boiler and the first floor appliance. Therefore, the first ring will operate with excess pressure, more water will enter the device on the second floor than is needed according to calculation, and the amount of water passing through the device on the first floor will accordingly decrease.

As a result, overheating will occur in the room heated by this device on the second floor, and underheating in the room on the first floor. To eliminate this phenomenon, special methods for calculating heating systems are used, and they also use double adjustment taps installed on the hot supply to the devices. If you close these taps at the appliances on the second floor, you can completely extinguish the excess pressure and thereby regulate the water flow for all appliances located on the same riser. However, uneven distribution of water in the system is also possible in individual risers. This is explained by the fact that the length of the rings and, consequently, their total resistance in such a system is not the same for all risers: the ring passing through the riser (closest to the main riser) has the least resistance; The longest ring passing through the riser has the greatest resistance.

Water can be distributed over individual risers by appropriately adjusting the plug (pass-through) taps installed on each riser. To circulate water, two pumps are installed - one working, the second - spare. Near the pumps, a closed bypass line with a valve is usually made. In the event of a power outage and the pump stops, the valve opens and the heating system operates with natural circulation.

In a pump driven system, the expansion tank is connected to the system before the pumps and therefore accumulated air cannot be removed through it. To remove air in previously installed systems, the ends of the supply risers were continued with air pipes on which valves were installed (to shut off the riser for repairs). The air line at the point of connection to the air collector is made in the form of a loop that prevents the circulation of water through the air line. Currently, instead of this solution, air valves are used, screwed into the top plugs of radiators installed on the top floor of the building.

Heating systems with bottom wiring are more convenient to use than systems with top wiring. So much heat is not lost through the supply line and water leaks from it can be detected and eliminated in a timely manner. The higher the heating device is placed in systems with lower wiring, the greater the pressure available in the ring. The longer the ring, the greater its total resistance; therefore, in a system with lower wiring, the excess pressures of devices on the upper floors are much less than in systems with upper wiring and, therefore, their adjustment is simpler. In systems with bottom wiring, the magnitude of the natural impulse is reduced due to the fact that, due to cooling in the supply risers, a braking movement from top to bottom occurs, therefore the total pressure acting in such systems is

Currently, single-pipe systems in which radiators are connected by both connections to one riser have become widespread; Such systems are easier to install and provide more uniform heating of all heating devices. The most common is a single-pipe system with bottom wiring and vertical risers.

The riser of such a system consists of a lifting and lowering part. Three-way valves can pass a calculated amount or part of the water into the devices; in the latter case, the remaining amount passes, bypassing the device, through the closing sections. The connection between the rising and falling parts of the riser is made by a connecting pipe laid under the windows of the upper floor. Air valves are installed in the upper plugs of devices located on the top floor, through which the mechanic removes air from the system during startup of the system or when it is abundantly refilled with water. In single-pipe systems, water flows through all fixtures in sequence, and therefore they must be carefully adjusted. If necessary, adjustment of the heat transfer of individual devices is carried out using three-way valves, and the water flow through individual risers is carried out using pass-through (plug) valves or by installing throttling washers in them. If an excessively large amount of water flows into the riser, then the first heating devices in the riser along the flow of water will give off more heat than is necessary according to the calculation.

As is known, the circulation of water in the system, in addition to the pressure created by the pump and natural impulse, is also obtained from the additional pressure Ap resulting from the cooling of water when moving through the pipelines of the system. The presence of this pressure made it possible to create apartment water heating systems, the boiler of which is not buried, but is usually installed on the kitchen floor. In such cases, the distance, therefore, the system works only due to the additional pressure resulting from cooling the water in the pipelines. The calculation of such systems differs from the calculation of building heating systems.

Apartment water heating systems are currently widely used instead of stove heating in one- and two-story buildings in gasified cities: in such cases, automatic gas water heaters (AGW) are installed instead of boilers, providing not only heating, but also hot water supply.

2. Comparison of modern heat supply systems of a thermal hydrodynamic pump type TC1 and a classic heat pump

After installing hydrodynamic heat pumps, the boiler room will look more like a pumping station than a boiler room. There will be no need for a chimney pipe. There will be no soot and dirt, the need for maintenance personnel will be significantly reduced, the automation and control system will completely take over the processes of managing heat production. Your boiler room will become more economical and high-tech.

Schematic diagrams:

Unlike a heat pump, which can provide a maximum coolant temperature of up to +65 °C, a hydrodynamic heat pump can heat the coolant to +95 °C, which means it can be quite easily integrated into an existing heating system of a building.

In terms of capital costs for the heat supply system, a hydrodynamic heat pump is several times cheaper than a heat pump, because does not require a circuit low-grade heat. Heat pumps and thermal hydrodynamic pumps, similar in name, but different in the principle of converting electrical energy into heat.

Like a classic heat pump, a hydrodynamic heat pump has a number of advantages:

· Economical (a hydrodynamic heat pump is 1.5-2 times more economical than electric boilers, 5-10 times more economical than diesel boilers).

· Absolutely environmentally friendly (possibility of using a hydrodynamic heat pump in places with limited maximum permissible limits).

· Complete fire and explosion safety.

· Does not require water treatment. During operation, as a result of the processes taking place in the heat generator of a hydrodynamic heat pump, degassing of the coolant occurs, which has a beneficial effect on the equipment and devices of the heat supply system.

· Quick installation. If there is supplied electrical power, installation of an individual heating point using a hydrodynamic heat pump can be produced in 36-48 hours.

· Payback period from 6 to 18 months, due to the possibility of installation in an existing heat supply system.

· Time until major repairs is 10-12 years. The high reliability of a hydrodynamic heat pump is built into the design and is confirmed by many years of trouble-free operation of hydrodynamic heat pumps in Russia and abroad.

3. Autonomous heat supply systems

Autonomous heat supply systems are designed for heating and hot water supply of single-family and semi-detached residential buildings. An autonomous heating and hot water supply system includes: a heat supply source (boiler) and a pipeline network with heating devices and water fittings.

The advantages of autonomous heat supply systems are as follows:

· lack of expensive external heating networks;

· the ability to quickly install and put into operation heating and hot water supply systems;

· low initial costs;

· simplification of solving all issues related to construction, since they are concentrated in the hands of the owner;

· reduction of fuel consumption due to local regulation of heat supply and absence of losses in heating networks.

Such heating systems, according to the principle of accepted schemes, are divided into schemes with natural coolant circulation and schemes with artificial coolant circulation. In turn, schemes with natural and artificial coolant circulation can be divided into single- and double-pipe. According to the principle of coolant movement, circuits can be dead-end, associated or mixed.

For systems with a natural flow of coolant, we recommend schemes with overhead wiring, with one or two (depending on the load and design features of the house) main risers, with an expansion tank installed on the main riser.

A boiler for single-pipe systems with natural circulation can be located on the same level as the lower heating devices, but it is better if it is buried, at least to the level of a concrete slab, in a pit or installed in the basement.

The boiler for two-pipe heating systems with natural circulation must be buried in relation to the lower heating device. The depth of burial is specified by calculation, but not less than 1.5-2 m. Systems with artificial (pump) stimulation of the coolant have a wider range of applications. It is possible to design circuits with upper, lower and horizontal coolant distributions.

Heating systems are:

· water;

· air;

· electric, including those with a heating electric cable laid in the floor of heated rooms, and battery-powered heat stoves (designed with permission from the energy supply organization).

Water heating systems are designed vertically with heating devices installed under window openings and with heating pipelines embedded in the floor structure. If there are heated surfaces, up to 30% of the heating load should be provided by heating devices installed under window openings.

Apartment air heating systems combined with ventilation should allow operation in full circulation mode (no people present) only on external ventilation (intensive household processes) or on a mixture of external and internal ventilation in any desired ratios.

The supply air undergoes the following treatment:

· taken from outside (to the extent sanitary standards per person 30 m3/h) mixed with recirculated air;

· cleaned in filters;

· heated in heaters;

· supplied to the serviced premises through a network of air ducts made of metal or embedded in building structures.

Depending on the external conditions, the system must ensure operation of the installation in 3 modes:

· outdoors;

· on full recycling;

· on a mixture of external air recirculation.

4. Modern heating and hot water supply systems in Russia

Heating devices are an element of the heating system designed to transfer heat from the coolant to the air to the enclosing structures of the serviced premises.

A number of requirements are usually put forward for heating devices, on the basis of which one can judge the degree of their perfection and make comparisons.

· Sanitary and hygienic. Heating devices should, if possible, have a lower body temperature, have the smallest horizontal surface area to reduce dust deposits, and allow dust to be easily removed from the body and the enclosing surfaces of the room around them.

· Economic. Heating devices must have the lowest reduced costs for their manufacture, installation, operation, and also have the lowest metal consumption.

· Architectural and construction. The appearance of the heating device must correspond to the interior of the room, and the volume they occupy must be the smallest, i.e. their volume per unit heat flow should be minimal.

· Production and installation. Maximum mechanization of work during the production and installation of heating devices must be ensured. Heating appliances. Heating devices must have sufficient mechanical strength.

· Operational. Heating devices must ensure controllability of their heat transfer and provide heat resistance and water resistance at the maximum permissible hydrostatic pressure inside the device under operating conditions.

· Thermal engineering. Heating devices must provide the highest density of specific heat flux per unit area (W/m).

4.1 Water heating systems

The most common heating system in Russia is water. In this case, heat is transferred to the premises by hot water contained in heating devices. The most common method is water heating with natural circulation of water. The principle is simple: water moves due to differences in temperature and density. Lighter hot water rises upward from the heating boiler. Gradually cooling down in the pipeline and heating devices, it becomes heavier and tends downward, back to the boiler. The main advantage of such a system is independence from power supply and fairly simple installation. Many Russian craftsmen cope with its installation on their own. In addition, the low circulation pressure makes it safe. But for the system to operate, pipes of increased diameter are required. At the same time, reduced heat transfer, limited range and a large amount of time required to start make it imperfect and suitable only for small houses.

Heating schemes with forced circulation are more modern and reliable. Here water is set in motion by work circulation pump. It is installed on the pipeline supplying water to the heat generator and sets the flow rate.

Quick start-up of the system and, as a result, quick heating of the premises is the advantage of the pumping system. The disadvantages are that it does not work when the power is turned off. And this can lead to freezing and depressurization of the system. The heart of a water heating system is the heat supply source, the heat generator. It is he who creates the energy that provides heat. Such a heart is boilers using different types of fuel. The most popular are gas boilers. Another option is a diesel fuel boiler. Electric boilers are distinguished by the absence of open flames and combustion products. Solid fuel boilers are not convenient to use due to the need for frequent firing. To do this, you need to have tens of cubic meters of fuel and storage space. And add here the labor costs for loading and preparation! In addition, the heat transfer mode of a solid fuel boiler is cyclical, and the air temperature in heated rooms fluctuates noticeably throughout the day. A place to store fuel reserves is also necessary for liquid fuel boilers.

Aluminum, bimetallic and steel radiators

Before choosing any heating device, you need to pay attention to the indicators that the device must meet: high heat transfer, low weight, modern design, low capacity, low weight. The most main characteristic heating device - heat transfer, that is, the amount of heat that should be in 1 hour per 1 square meter of heating surface. The best device is considered to be the one with the higher this indicator. Heat transfer depends on many factors: heat transfer medium, design of the heating device, installation method, paint color, speed of water movement, speed of air washing the device. All devices of the water heating system are divided by design into panel, sectional, convectors and columnar aluminum or steel radiators.

Panel heating devices

Manufactured from high-quality cold-rolled steel. They consist of one, two or three flat panels, inside of which there is a coolant, they also have ribbed surfaces that are heated by the panels. Heating of the room occurs faster than when using sectional radiators. The above panel water heating radiators come with side or bottom connections. The side connection is used when replacing an old radiator with a side connection or if the slightly unaesthetic appearance of the radiator does not interfere with the interior of the room.

Sectional water heating devices

Made from steel, cast iron or aluminum. They use the convective method of heating a room, meaning they give off heat by circulating air through them. The air passes through the convector from top to bottom and is heated by a large number of warm surfaces.

Convectors

They provide air circulation in the room, when warm air rises, and cold air, on the contrary, falls down and, passing through the convector, is heated back up.

Steel water heating radiator It can be either sectional or panel type. Steel is most often subject to corrosion and therefore these radiators are most suitable for enclosed spaces. Two types of radiators are produced: with horizontal channels and with vertical channels.

Aluminum radiators

Aluminum water heating radiators are lightweight and have good heat dissipation, are aesthetically pleasing, but are expensive. Often they cannot withstand high pressure in the system. Their advantage is that they heat the room much faster than cast iron radiators.

Bimetallic radiators

Bimetallic water heating radiators consist of an aluminum body and steel pipes through which the coolant moves. Their main advantage over other radiators is durability. Their operating pressure reaches up to 40 atm, while aluminum water heating radiators operate at a pressure of 16 atm. Unfortunately, on this moment On the European market it is very rare to find these bimetallic water heating radiators on sale.

Column-type cast iron radiators are practically the most common type of radiator. They are durable and practical to use. Cast iron radiators are produced in two-column sections. These heating devices can be operated at the highest operating pressure. Their disadvantage is their heavy weight and inconsistency with the design of the room. The above radiators are used in systems with poor coolant preparation. They are quite inexpensive in price.

4.2 Gas heating

The next most frequently used type of heating for a country house in Russia is gas. In this case, heating devices adapted for burning gas are installed directly in the heated rooms.

Gas furnaces are economical and have high thermal performance. A distinctive feature of such furnaces is uniform heating outer surface. Gas fireplaces are used as additional heat sources, which also add special comfort to the interior.

The advantage of gas heating lies, first of all, in the relatively low cost of natural gas. Its use allows you to automate the fuel combustion process, significantly increases the efficiency of heating equipment, and reduces operating costs. But it is explosive and unacceptable for self-production and installation.

4.3 Air heating

Air heating systems are distinguished depending on the method of creating air circulation: gravity and fan. Gravitational air system heating is based on the difference in air density at different temperatures. During the heating process, natural air circulation occurs in the system. A fan system uses an electric fan to increase air pressure and distribute it throughout ducts and rooms (forced mechanical circulation).

The air is heated in air heaters heated from the inside by water, steam, electricity or hot gases. The heater is placed either in a separate fan chamber (central heating system) or directly in the room that is heated (local system).

The absence of freezing coolant makes this type of heating suitable for houses with intermittent use. Air heating will quickly warm up the house, and automatic regulators will maintain the temperature you set. The disadvantages of such heating include the danger of the spread of harmful substances by moving air.

4.4 Electric heating

Direct stationary electric heating systems are very reliable, environmentally friendly and safe. Up to 70% of low-rise buildings in Scandinavia and Finland are heated with electricity. Electric heating equipment can be divided into 4 groups: - wall-mounted electric convectors; - ceiling heaters; - cable and film systems for floor and ceiling heating; - control thermostats and programmable devices.

Thanks to such diversity, it is easy to choose the appropriate option for each specific room. The costs of equipment and operation of electrical systems are very low. Systems can automatically turn on and off to maintain the temperature at a set level. Let's say, lower it to a minimum during your absence. This feature significantly saves energy costs. Rising prices for different kinds fuels make electric heating very attractive for owners of private houses. The disadvantage of electric heating systems is that you have to install optional equipment to provide the home with hot water. In addition, we still experience long power outages, and owners of such a system should consider an additional source of heating - just in case.

4.5 Pipelines

Pipelines for supplying coolant to heating devices can be made of steel water and gas pipes, copper pipes and polymer materials (metal-plastic pipes, polypropylene pipes and cross-linked polypropylene pipes). Mains made of steel pipes are not suitable for hidden connections to radiators. All other pipes can be “hidden” under finishing materials in compliance with certain system installation technologies. It should also be noted that installation of a heating system made of copper pipes is not allowed if aluminum sectional radiators are selected as heating devices.

4.6 Boiler equipment

As a rule, heating of urban housing is provided from centralized boiler houses and city heating networks, while heating country houses mainly carried out from its own (autonomous) heat sources and only occasionally from a boiler house operating for a group of buildings.

The boiler equipment market in Russia is quite saturated. Almost all leading Western companies producing boiler equipment have their representative offices with us. Although Russian boilers are widely represented on the market, they still cannot withstand competition with imported models in terms of consumer qualities. At the same time, almost all Western manufacturers develop and supply boilers adapted to our conditions to the Russian market:

· multi-fuel boilers;

· gas boilers operating without electricity.

Multi-fuel boilers

Almost all companies produce boilers that run on liquid fuel and gas, and some companies add a solid fuel option. It should be noted that multi-fuel boilers, due to the design of the burner, are quite noisy.

Gas boilers working without electricity

Nowadays, the bulk of boilers are designed to operate in heating systems with forced circulation of coolant, and in a typical Russian case of a power outage, the boiler simply stops and does not work until there is no electricity.

Boiler room control systems

The boiler equipment control system, depending on the purpose of the boiler room (only heating of one building, heating and hot water supply, the presence of underfloor heating circuits, heating and hot water supply of several buildings), can vary from the simplest, made on thermostatic regulators, to complex with microprocessor control.

5. Prospects for the development of heat supply in Russia

The main factors determining the prospects for the development of heat supply in Russia include:

1. A course towards restructuring the unified energy system with the formation of a 3-tier system of enterprises: heat producers, heating networks and energy sellers. The restructuring will be accompanied by a redistribution of ownership in the energy complex in favor of private enterprise. It is expected to attract large investments, including from abroad. In this case, the restructuring will affect the “big” energy sector.

2. Housing and communal reform related to the reduction and removal of subsidies to the population in paying for utility services, including thermal energy.

3. Stable economic growth in the construction sector.

4. Integration of advanced heat and power technologies from Western countries into the country's economy.

5. Revision of the regulatory framework for the thermal power industry, taking into account the interests of large investors.

6. Bringing domestic prices for fuel and energy resources closer to world prices. The formation of a “deficit” of fuel resources for export potential in the domestic market, primarily natural gas and oil. Increasing the share of coal and peat in the country's fuel balance.

7. Formation of a balance of municipal and market mechanisms for organizing and managing regional heat supply.

8. Formation of modern accounting and billing systems in the market for the production, supply and consumption of thermal energy.

Conclusion

Russia is one of the countries with a high level of centralized heat supply. The energy, environmental and technical advantages of centralized heat supply over autonomous heat supply under conditions of state ownership monopoly were considered a priori. Autonomous and individual heat supply to individual houses was taken out of the scope of the energy sector and developed according to the residual principle.

In the centralized heat supply system, CHP plants - enterprises for the combined production of electricity and heat - have become widespread. Technologically, CHP plants are focused on the priority of power supply; the associated heat is in greater demand in the cold season, and discharged into the environment in the warm season. It is not always possible to harmonize the modes of production of thermal and electrical energy with the modes of their consumption. However, the high level of large-scale energy has predetermined “technological independence” and even a certain export potential of the country, which cannot be said about small-scale thermal energy. Low prices for fuel resources and the economically unreasonable price of thermal energy did not contribute to the development of “small” boiler building technologies.

Heat supply is an important sector in our lives. It brings warmth to our home, provides coziness and comfort, as well as hot water supply, which is necessary every day in the modern world.

Modern heat supply systems significantly save resources, are more convenient to use, meet sanitary and hygienic requirements, are smaller in size and look more aesthetically pleasing.

Bibliography

1. http://www.rosteplo.ru

2. http://dom.ustanovi.ru

3. http://www.boatanchors.ru

4. http://whttp://www.ecoteplo.ru

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Arranging numerous communications in a private building is a very labor-intensive task, since this work requires increased attention from the owners, and sometimes very specific construction skills. At the same time, as a rule, special importance is attached to it, since the comfort of living in the house will depend on its quality.

Today, it is not enough to simply install and connect all the elements of the heating circuit; it is also important to ensure that the entire system functions not only stably, but also as economically as possible. The constant increase in electricity tariffs, rising prices on the fuel market and other unpleasant factors oblige consumers to equip modern heating for a private home according to the principle of lowest energy consumption. What kind of modern heating systems are found, as well as the features of their design from the point of view of their efficiency, will be discussed further.

Traditional heating elements at the present stage

Innovative materials for the arrangement of heat supply have become firmly established in modern life, however, sometimes their use is completely optional, since it is possible to equip heating in a private house using traditional and familiar elements, manufactured, however, in accordance with the latest developments.

Heating boilers

Modern heating of a country house requires a powerful heating boiler.

Among the new products in this category that have appeared on the construction market, the following samples can be noted:

• induction type boilers operating from electrical network. These structures are a pipe consisting of a dielectric with a metal core placed inside. They got their name due to the presence of an induction coil wound on top of the pipe. It is this part of the boiler that is the source of energy currents. As a result, the device heats up and transfers thermal energy to the coolant, which, as a rule, is ordinary water. Among the advantages of this model is high productivity, despite its very small size. In addition, the design of the induction boiler does not have components prone to wear, which is also important;
• boiler, called an electrode boiler. Its shape is also extremely convenient due to its small size. Heating of the coolant is achieved by placing two electrodes inside it, as a result of which the water, which is an electrolyte, is heated.

  The peculiarity of this boiler model is that it is completely safe for operation, since if even a minimal leak occurs, the mechanism will immediately stop working due to the principle of its design.

  However, due to the fact that the functioning of such a boiler directly depends on electricity, its operation can hardly be called economical, since electricity costs will be very significant, despite the assurances of many sellers of this equipment;

• boilers called condensing boilers. These mechanisms are heating elements that run on gas, or more precisely, on the energy obtained from its combustion. This means that all combustion products condense on a specially designated heat exchange element, due to which it is heated.

  What makes such boilers notable is that their performance is very high (the efficiency can reach 100% or even more, provided that the total volume of thermal energy released is taken as 100%).

  The operating principle of such a boiler is based on a process called pyrolysis. Firewood, which serves as the main fuel, burns in two stages. Initially, combustion takes place in conditions of a small amount of oxygen, resulting in the appearance of ash and gas, which subsequently burns in a separate chamber. Thanks to this operating principle, it becomes possible to control the operation of the boiler and distribute heating throughout the entire home as conveniently as possible.

Modern heating batteries

Modern heating systems for a private home usually cannot do without radiators, among which special attention should be paid to the following models:

• The best choice for installing a heat supply system in a private building is batteries made of aluminum. These products have excellent technical characteristics, and also, no less important, quite affordable cost;
• There are also convectors made of copper-aluminum alloy, which belong to bimetal devices, that is, those for the production of which two metals were used. These devices take the form of a copper pipe equipped with special aluminum fins.

Installation of modern radiators can be done in three ways:

• on the floor surface;
• on the wall, when the device is fixed to its surface using brackets;
• inside the floor (in this case, installing a weak, low-power fan near the battery can help increase thermal energy transfer rates).

Types of heating pipes

Modern heating systems for private houses often have one of the two most common pipe options in their designs:

1. Pipes made of polypropylene. Their strengthening is achieved through reinforcement with aluminum-based foil or, alternatively, fiberglass. Such products are characterized by high strength, they are convenient to use and easy to install. The strength of the connections of polypropylene pipes is explained by special welding using low temperature technology.
2. Pipes made of such innovative material as cross-linked polyethylene. As a rule, such models are used exclusively for the installation of a modern structure called a “warm floor”. These products are distinguished by their high strength and at the same time quite unexpected flexibility, which makes them possible to install with a bend.

As an alternative, some experts recommend using pipes made using corrugated stainless steel. In this case, the fastening elements of the structural parts of such pipes should be special fittings, the operation of which is based on the use of silicone treated at high temperatures.

But the option with stainless steel pipes is still more suitable for a city apartment than for a private house, since their installation in a city will require significantly lower costs than in a private building.

Innovative heating materials

Having mentioned traditional methods of installing heating systems, one cannot fail to note those heat supply options that have become popular relatively recently, but at the same time have managed to gain wide popularity. As a rule, most of these products operate on the principle of maximum energy conservation, while such properties as environmental friendliness are also taken into account.

Heated floor system

You can resort to a technology called heated floors for the reason that the use of standard radiators implies uneven distribution of heat in the room. A large number of The air heated by the batteries escapes through the roof of the house.

In order to significantly reduce heat loss, it is worth considering installing a heat source under the floor surface. In this case, the temperature parameter in the home will level out and will be almost the same both under the ceiling and in the floor area.

To date, three options for installing heated floors have been developed, which include the following:

1. Water-based heated floor. In this case, it is necessary to lay a solid pipe made of metal-plastic or cross-linked polyethylene into the screed. The maximum possible heating of the coolant in such a system should reach 40 °C.
2. A cable operating from the electrical network. This option is a good alternative to a water system, provided that the main source of energy for heating is electricity. There are also samples in the form of heating mats.
3. Warm floor of film type. This system looks like a thin mat equipped with small tracks along which current flows. It is very convenient to install such a warm floor, since its installation does not require any serious preparatory measures, and the installation of electric film can be done on any surface (tiles, linoleum, laminate).

Modern heating with infrared heaters

To modern equipment designed to heat a private house, also include heaters that operate using infrared radiation. Today you can find two examples of these devices: mechanisms equipped with a quartz tube with a spiral inside and operating at high temperature, as well as panels whose operating temperature is low.

The second version of the heaters can also be equipped with a spiral, heated, however, to no more than 90 °C. But usually the design of such a model includes a ceramic panel, behind which the main heating part in the form of a film is located.

An interesting fact is that such equipment can be installed by hand, and its maintenance is extremely simple: the structure is suspended from the surface of the ceiling or wall, and then connected to the electrical network.

Obvious savings in this case are achieved due to two main factors:

1. The heat distribution in this case is almost identical to that observed in a heated floor system - the heated air is distributed evenly over the entire area of ​​the room, leaving no cold areas and preventing heat loss.
2. Thanks to physical properties Infrared radiation, the comfortable temperature obtained with the help of such heating can be significantly lower than usual and amount to about 16 - 18 °C, which has a positive effect on the consumption of thermal energy and allows you to save money.

Use of thermal accumulators

As is known, in many utility organizations, electricity tariffs at night differ significantly downwards compared to daytime electricity supply. Therefore, in order to coordinate the process of heating a residential building throughout the whole day, you can use a device called a thermal accumulator, which is a capacious tank equipped with thermal insulation. It's not difficult to do at all.

Thus, with the help of a heat accumulator, you can configure the system so that the water in the heating circuit will be heated exclusively at night, when electricity charges are lower, and during the day the coolant will be gradually transferred to the radiators.

Its installation in conjunction with a heating boiler operating on solid raw materials will help improve its performance properties. The power of such equipment is quite enough to accumulate heat with just one load of fuel per day.

Operating principle of solar collectors

Despite the seemingly archaic nature of such a device at first glance, a solar collector, the operating principle of which is based on using sunlight as the main source of energy, is capable of heating a private building to the required extent. They work on the same principle, which are very practical.

Externally, this device is a dark-colored tank with glass on top. Thanks to the black tint, which attracts heat faster than the light one, the tank heats up, and heat loss is minimal thanks to the convection provided by the glass structure.

Of course, such equipment is relevant only during daylight hours, and at night and in cloudy weather, as it becomes clear, such a convector will not be of much use.

However, its use can help reduce home heating costs, especially in hot climates.

Heat pump - a modern heating device

A mechanism that is used in many private buildings today is a heat pump. Heating systems equipped with this device are highly economical, even in comparison with the above-described infrared devices and heated floor designs. This is explained by the fact that the electricity consumed by the pump is not used to create thermal energy, but to transfer it to heating devices from a completely different source.

According to the principle of operation, such a pump is in many ways reminiscent of a standard refrigerator, with the only difference being that its operation is aimed at reverse side, but it is not for cooling, but for heating.

Thus, we can say with confidence that the use of modern heating devices in private homes can significantly reduce energy consumption and save a significant portion of financial resources. It is only important to pay attention to the high-quality installation of these products, therefore, if difficulties arise with their connection and operation, you can always contact qualified specialists who have various photos of heating devices and detailed videos that simplify all installation work.

The heating season in Russia lasts about seven months. For owners of private houses and those who are just planning to become one, the issue of efficient heating of the premises becomes a difficult task that is not so easy to solve. Let's try to figure out what modern heating systems in a private home are.

Most often, water or various antifreeze liquids that circulate through pipes are used for heating. The liquid is heated using gas boilers, which can operate on liquid, solid and gas fuels. Recently, electrode and induction boilers have been used as heating elements.

Water heating is popular due to the availability and efficiency of the coolant among owners of cottages and other suburban housing. The water system is easy to install yourself. The positive thing is that the volume of water in the system remains constant.

The disadvantages of water heating are the long time it takes to warm up the room, possible leaks and pipe ruptures. Cannot be disabled water system in winter, as the water will freeze and burst the pipes.

Progressive heating systems

The design of modern heating systems for private houses is fundamentally different from traditional heating methods. Heating technology is developing rapidly every year. The equipment is being improved and becomes more efficient.

New energy sources are emerging that meet the requirements for protecting the natural environment and the general comfort of equipment operation.

An innovative development of Russian scientists is the PLEN infrared heating system. It consists of the thinnest polymer film and a resistive heating element made of carbon filaments.

PLEN emits the thermal component of sunlight, which is absorbed by the floor, ceiling, furniture and creates a comfortable room temperature.

Characteristics

The maximum surface temperature of this structure is 60°C, but to create the most comfortable conditions in the house, 30° - 40°C is sufficient.

PLEN can be laid over the entire surface of the base of the room, covering it with laminate or any other type of covering. If you mount the system on the ceiling, you will get a feeling of warmth and comfort like from the sun. It is also possible to attach the structure to the walls, but its effectiveness will suffer.

One of the advantages of a film heater is the absence of liquid coolant. This eliminates the need to install complex systems, leaks, and freezing of liquids. In addition, film heating systems have a number of other advantages:

• do not dry the air;
• there are no intense heat flows;
• do not create convective currents;
• fireproof;
• easy to install;
• completely safe for humans and the environment.

Another argument in favor of PLEN for a country house is many years of research by scientists. They proved that long-wave infrared radiation at moderate power has a beneficial effect on the human body.

The main disadvantage of an infrared heating system is its high cost. To install a heating system for the entire house, you will have to make serious financial investments, which will not pay off very soon.

Geothermal systems

An innovation in heating a private home is the extraction of heat from the ground, which is located in the local area. For this, a geothermal installation is used. Its design consists of a heat pump operating on the principle of a refrigerator, only for heating.

A shaft is created near the house where it is necessary to place a heat exchanger. Through it, groundwater will flow into the heat pump and release heat, which will be used to heat the building.
When heating a country house, antifreeze is used as a coolant. For this purpose, a special tank is installed in the mine.

It is very easy to use thermal energy, the source of which is sunlight. Latest systems heating of a country house, powered by solar energy, represent a collector and a reservoir.

The structure of the tubes that make up the collector reduces heat loss to a minimum. Based on their design features, solar collectors can be vacuum, flat and air.

They must be placed as high as possible.

Nuances

This type of heating is suitable only for warm regions of the country where the bright sun shines at least 20-25 days a year. Otherwise, additional heating systems must be installed. Another disadvantage of solar panels is the high cost and short service life of the batteries needed to store electricity.

Hydrothermal systems

If your country house is located next to an ice-free body of water, then the necessary heat energy can be obtained from the water.

To do this, a heat exchanger probe is placed at the bottom of the reservoir, and a heat pump is installed in the house. How larger size probe, the more efficient the hydrothermal installation.

Air systems

In warm climates, an air-to-air system can be used. The simplest types of such heat pumps are inverter air conditioners. They are installed like regular air conditioners. The efficiency of their work decreases at sub-zero temperatures, and at -30°C and below it is reduced to zero.

Wind energy has long been used to generate electricity. But it can also be used to heat suburban housing. Scientists have created a gearless wind power generator that is mounted on a vertical axis of rotation on the roof of a house. To reduce noise during operation of the structure, the axle must be equipped with a vibration isolator. An electric water heater and a heat accumulator are placed in the basement.

This device is quite difficult to manufacture, has a large size and weight. It is long and difficult to install. To obtain maximum wind energy, it is necessary to build a high enough tower.

Advantages and disadvantages

The undoubted advantage of this type of heating is its environmental friendliness. Extracting energy from wind does not cause any damage to the environment. In addition, this energy is absolutely free, and the costs of manufacturing and installing the equipment are relatively low.

Despite its undoubted advantages, this method of heating country houses is not popular, due to the variability of wind strength and speed.

Electrical space heating refers rather to traditional heating methods that have been modernized in recent decades. Electrical appliances are easy to use, convenient and reliable. They have long been used for local heating.

To evenly heat the entire area of ​​a room using electricity, heated floors are used. This system is convenient for use in a country private house.

Warm floor system

Underfloor heating technology is a convenient and economical system for heating a room. Modern installations use advanced materials. Lightweight and durable polymer materials are used for the manufacture of pipelines.

The basis of a warm electric floor is a heating cable. The main thing in this type of heating is the quality of the cable, on which the efficiency of the system and its service life depend.
Warm floors using water do not emit harmful substances or electromagnetic radiation. Water is a cheap and heat-intensive coolant. A pipeline network through which the liquid flows is installed between the base and the floor covering. Compared to the electric "warm floor" system, this type of heating is much cheaper.

Energy supply policy pursued in last years, involves a transition to renewable energy sources. Increasingly, not gas and coal are used to produce electricity, but sun, wind, and water energy. These are environmentally friendly energy sources that do not pollute the environment with emissions and discharges.