Description:

With full use of the generated electrical and thermal energy, high economic values ​​are achieved. system indicators, and high energy efficiency ensures, in turn, a reduction in the payback period for funds invested in equipment.

Co-production of heat and electricity

Co-production systems of heat and electricity: balancing the ratio of produced heat and power

A. Abedin, Fellow of the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE)

In the described cogeneration systems, primary fuel is spent on the simultaneous production of electrical or mechanical energy (power) and useful thermal energy. In this process, it is essential that the same fuel works “twice”, thereby achieving high energy efficiency of the systems.

With full use of the generated electrical and thermal energy, high economic indicators of the system are achieved, and high energy efficiency ensures, in turn, a reduction in the payback period for funds invested in equipment.

The configuration of the cogeneration (cogeneration) system of heat and electricity is determined by the extent to which the actual thermal and electrical loads correspond to the production of thermal and electrical power. If there is a market ready to consume excess heat or electricity, balancing the ratio of thermal and electrical power is not critical to the system.

For example, if electricity can be consumed (on acceptable terms), then the basis for the operation of the cogeneration system becomes the on-site heat demand (the system is designed to supply the heat load). Excess electricity can be sold, and shortfalls can be compensated for by purchases from other sources. The result is high energy efficiency, and the actual ratio of heat and power generation for the power plant matches the needs of the plant's site.

As an example of the effective relationship between thermal and electrical power, consider a steam boiler that produces 4,540 kg of steam per hour, supplied at a pressure of about 8 bar, and consumes 4,400 kW of flue gas energy for this (with an average boiler efficiency of 75%). With the same amount of fuel gas energy consumed, a standard 1.2 MW gas turbine can produce required amount steam using waste heat recovery. As a result, about 1,100 kW of electricity can be generated “without the cost” of fuel. This is an example of a very good heat-to-power ratio, which gives the system attractive economics.

Let us now imagine an absorption chiller serving an air conditioning system with the same steam requirements. During partial load operation, the same gas turbine produces electricity in an inefficient manner (usually). In such a system, waste heat is not completely used, unless there is some other consumer of this heat on site. Thus, if the system operates at part load for a long time, its economic performance is low.

The designer of a heat and power co-production system must solve difficult problems of ensuring the optimal ratio of thermal and electrical power, also taking into account daily and seasonal changes in this ratio. Typical methods for balancing the ratio of heat and electricity production are discussed below.

Method I: Use of Gas Turbines and Gas Engine Generators

Let's compare the configurations of a gas turbine power plant with a high ratio of thermal and electrical power and installations of gas internal combustion engines (gas engine) with a low ratio of thermal and electrical power. As will be shown below, depending on the energy loads of the facility, both gas turbine and gas engine installations may be appropriate.

Example A. Typically, in a building with a central air conditioning system, there is a high cooling demand at peak design conditions, which requires a large number of thermal energy if absorption chillers operate on jointly generated waste heat.

Let's say that at peak demand the building's cooling requirement is 1,760 kW and about 1,100 kW of electrical power.

A gas turbine plant can operate with high cogeneration efficiency as follows:

1. Gas turbine performance parameters at 35 °C: 1,200 kW of electrical power at 5,340 kW of flue gas energy consumption (electricity generation 22.5%), steam output 7 kg/s at a temperature of 540 °C.

2. Under the conditions of Example A, the waste heat recovery boiler provides approximately 2,990 kW of heat to a single-stage absorption chiller. With thermal energy losses of 7% (due to radiation and losses in pipes with hot water), to ensure the required refrigeration capacity of the absorption chiller, the boiler supplies it with hot water at a temperature of 121 ° C.

3. The ratio of thermal and electrical power (the amount of thermal energy in British units MBtu/h per 1 kW/h ) in example A is 8.5 (10,200 / 1,200).

Example B. For the same building as in example A, consuming only 750 kW of electricity and 616 kW of “cold” air conditioning when operating at part load, the ratio of thermal and electrical power is determined by the following factors:

1. Performance parameters of a gas engine power plant at 25 °C: 750 kW of electrical power with 2,000 kW of flue gas energy consumption (electricity generation 37.5%), recovery of waste heat from cooling water in the amount of 100 kW from the aftercooler circuit and recovery of exhaust gas heat engine in the amount of 500 kW.

2. A total of 959 kW of recovered heat allows the production of approximately 616 kW of cold using a single-stage absorption chiller when supplied to it hot water with a temperature of 90 °C.

3. The ratio of thermal and electrical powers (the amount of thermal energy in units of MBtu/h per 1 kW/h) in example B is 4.4 (3,300 / 750).

The ratio of thermal and electrical power changes from 8.5 (for a gas turbine installation) at peak loads to 4.4 for a gas engine installation in part-load mode. A rational choice of cogeneration system configuration allows you to achieve an optimal load ratio and ensure the highest efficiency of the joint production of heat and electricity.

Method 2: Using Hybrid Chillers

To balance the production of heat and electricity in cogeneration power plants that provide central air conditioning systems with recovered heat, a hybrid chiller is required.

During periods of relatively low electrical load (when there is little heat recovery available for the absorption chiller), the electric chiller helps balance this ratio by increasing the electrical load while increasing the amount of waste heat to improve cogeneration efficiency.

Method 3: using thermal energy storage

Thermal energy storage devices (accumulators) are used both in cooling systems, and in heat supply systems. The use of storage tanks using hot water (temperature from 85 to 90 ° C) can “save” the existing “waste” heat. The system can also be designed to use hot water with temperatures above 100 °C (at elevated pressure).

Since it is not economical to “store” electricity (especially for small cogeneration plants) to achieve high heat generation efficiency, in such plants excess thermal energy must be stored to meet electricity demand.

To fully utilize the heat from the flue gases to co-produce heat and power for central air conditioning systems, it is necessary that the heat-using chillers operate at maximum capacity and any excess refrigeration capacity is stored as chilled water stored in storage tanks.

For this purpose, existing water tanks (for example intended for a fire extinguishing system) or specially manufactured tanks can be used.

Thermal energy storage devices can be used to store hot water with a temperature in the range from 85 to 90 °C (water at this temperature is intensively used, for example, in textile factories). Since the cogeneration plant produces hot water continuously, the hot water can be stored in tanks for industrial use.

The figure shows a simplified diagram of a piping system for a hot water production and storage plant, part of a cogeneration power plant, which uses a generator driven by a 900 kW turbocharged gas engine at 1,000 rpm. The diagram does not show all the necessary control valves and instruments for safe and economical operation.

Method 4: Conditioning Inlet Air Using a Gas Turbine

Example A: Gas turbine inlet air conditioning is a technology that can be used in gas turbine generator installations to balance the thermal to electrical output ratio. This technology uses inlet air cooling to increase capacity at peak loads in the summer (using either thermal energy storage or in-line waste heat chillers) or inlet air heating to increase cogeneration efficiency at part load, especially in winter (more heat is generated). energy per 1 kW of electricity).

Cooling the inlet air increases the performance and efficiency of the gas turbine generator. It is widely used in cogeneration systems where waste heat is used to centrally supply chilled water.

Such systems may or may not have thermal energy storage. This design ensures that generators operate with gas turbines according to the required loads, since the increase in power generation, due to the cooling of the inlet air, also leads to an increase in waste heat supplied to the absorption chillers.

Under part-load conditions, the use of a gas turbine with cooling coils at the inlet is unprofitable, since the additional pressure drop across the cooling coil (now redundant) causes an increase in thermal power (increased fuel consumption). In CHP plants, part load efficiency can be improved, as shown in the table, by using a conventional gas turbine with a rated power of 1200 kW used in a CHP plant producing industrial pressurized steam. 3 bars.

When operating at 40% of maximum load, gas turbine inlet air preheating (limited by plant design) can be used to balance the heat to power ratio, as reduced gas turbine efficiency results in increased waste heat available and resulting in increased overall efficiency. cogeneration. It is stated that the efficiency of co-production of heat and electricity increases by more than 15% if, under part-load conditions, the inlet air is heated from 15 to 60 °C. Most gas turbine manufacturers can provide performance data at air temperatures down to 60°C. Before designing a system with this capability, the inlet air heating limitations must be reviewed with the gas turbine manufacturer.

Example B: To increase the generation of "waste" heat in the high temperature, oxygen-enriched exhaust gases of a gas turbine, additional afterburning is used in the waste heat stream. More heat means a higher heat to power ratio, improving the economics of the heat and power co-production process.

Conclusion

Cogeneration systems operate efficiently if all or most of the electrical and thermal energy is used.

In real conditions, the load varies, so most systems require balancing the ratio of thermal and electrical power produced to ensure efficient and economical operation of the cogeneration plant.

Heat-power balancing systems should be adopted in cogeneration plants from the outset to ensure optimal utilization of electrical and thermal power output and thereby reduce fuel costs, as well as improve the economics of the system.

Translated with abbreviations from the ASHRAE journal.

Translation from English L. I. Baranova.

Heat value
Heat sources
Heat production and heat supply
Use of heat
New heat supply technologies

Heat value

Heat is one of the sources of life on Earth. Thanks to fire, the origin and development of human society became possible. From ancient times to this day, heat sources have served us faithfully. Despite the unprecedented level of technological development, man, like many thousands of years ago, still needs warmth. With population growth globe, the need for heat increases.

Heat is one of the most important resources of the human environment. A person needs it to maintain his own life. Heat is also required for technologies, without which modern man cannot imagine his existence.

Heat sources

The most ancient source of heat is the Sun. Later, fire was at man's disposal. On its basis, man created a technology for producing heat from organic fuel.

Relatively recently, nuclear technologies began to be used to produce heat. However, burning fossil fuels still remains the main method of heat production.

Heat production and heat supply

By developing technology, man has learned to produce heat in large volumes and transfer it over fairly long distances. Heat for large cities is produced at large thermal power plants. On the other hand, there are still many consumers who are supplied with heat by small and medium-sized boiler houses. In rural areas, households are heated by domestic boilers and stoves.

Heat production technologies make a significant contribution to environmental pollution. When burning fuel, a person emits a large amount of harmful substances into the surrounding air.

Use of heat

In general, a person produces much more heat than he uses for his own benefit. We simply dissipate a lot of heat into the surrounding air.

Heat is lost
due to imperfect heat production technologies,
when transporting heat through heat pipes,
due to imperfection heating systems,
due to the imperfection of housing,
due to imperfect ventilation of buildings,
when removing “excess” heat in various technological processes,
when burned production waste,
with exhaust gases from vehicles powered by internal combustion engines.

To describe the state of affairs in the production and consumption of heat by humans, the word wastefulness is well suited. An example, I would say, of blatant wastefulness is the flaring of associated gas in oil fields.

New heat supply technologies

Human society spends a lot of effort and money to obtain heat:
extracts fuel deep underground;
transports fuel from fields to enterprises and homes;
builds installations for heat generation;
builds heating networks for heat distribution.

Probably, we should think: is everything reasonable here, is everything justified?

So-called technical and economic advantages modern systems Heat supply is inherently momentary. They are associated with significant environmental pollution and unreasonable use of resources.

There is heat that does not need to be extracted. This is the heat of the Sun. It needs to be used.

One of the ultimate goals of heating technology is the production and delivery of hot water. Have you ever used an outdoor shower? A container with a tap installed in an open place under the rays of the Sun. Very simple and affordable way supply of warm (even hot) water. What's stopping you from using it?

With the help of heat pumps, people use the heat of the Earth. A heat pump does not require fuel, nor does it require a long heating pipeline with its heat losses. The amount of electricity required to operate a heat pump is relatively small.

The benefits of the most modern and advanced technology will be negated if its fruits are used stupidly. Why produce heat away from consumers, transport it, then distribute it among homes, heating the Earth and the surrounding air along the way?

It is necessary to develop distributed heat production as close as possible to the places of consumption, or even combined with them. A method of heat production called cogeneration has long been known. Cogeneration plants produce electricity, heat and cold. For the fruitful use of this technology, it is necessary to develop the human environment as a unified system of resources and technologies.

It seems that in order to create new heat supply technologies it is necessary
review existing technologies,
try to get away from their shortcomings,
assemble on a single basis for interaction and addition each other,
take full advantage of their advantages.
This implies understanding

Field of activity (technology) to which the described invention relates

The invention relates to thermal power engineering and can be used in the combined production of heat, cold and electricity using thermal power plants.

DETAILED DESCRIPTION OF THE INVENTION

There is a known method of operation of a mobile installation for the combined production of electricity, heat and cold, in which a generator converts the mechanical energy of a rotating engine shaft into electricity, the exhaust gases passing through a heat exchanger give off heat to a coolant liquid for heat supply during the heating season or to the refrigerant of an absorption refrigeration machine for cooling in the summer period .

The disadvantages of this method of operation of the installation include low efficiency associated with the release of a significant part of unused thermal energy into the atmosphere through the air cooling devices of the internal combustion engine and the refrigeration machine, the low degree of use of the refrigerating power of the absorption refrigeration machine in the summer during periods of low ambient temperature.

The method of operation of a cogeneration system is also known: the first internal combustion engine produces useful energy, which is converted into electrical energy With the help of an electric generator, the second internal combustion engine is used to drive the compressor of the refrigeration machine, which produces cold in the summer; heat recovered from the engine jacket and exhaust gases is used to supply heat to consumers in the winter.

The disadvantage of the method of operation of this installation is the low efficiency of use waste heat internal combustion engines, significant energy costs for operating the compressor of a refrigeration machine.

There is a known method of operation of a trigeneration system that simultaneously provides heat/cooling and electricity, in which heat supply in the cold period is carried out by recycling the heat of exhaust gases and coolant of an internal combustion engine, the mechanical energy of the rotating shaft of the engine is converted into electricity, the cold is generated in the summer in compression refrigeration machine.

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The disadvantages of the method of operation of this installation include low efficiency due to insufficient use of waste heat from the internal combustion engine and significant energy costs for operating the compressor of the refrigeration machine.

The closest technical solution (prototype) is a method of injecting cooled air into a gas turbine, in which one is used to convert the heat of combustion products into mechanical energy, followed by converting it into electrical energy in an electric generator. The second heat engine is used as a source of thermal energy converted into cold energy in an absorption refrigeration machine. The cold produced in the absorption refrigeration machine is used for cooling atmospheric air before compression. When the load on the refrigeration system decreases, the pressure of the gas supplied to the heat engine is reduced.

The disadvantage of the method of operation of this installation is that during the period of incomplete loading of the absorption refrigeration machine, as a result of a decrease in the pressure of the gas used by the heat engine, the temperature of the water supplied from the absorption refrigeration machine to the air-water heat exchanger increases, which leads to a decrease in the degree of cooling of the atmospheric air, supplied to the compressor, and accordingly to a decrease in the electrical power of the installation.

The objective of the invention is to increase the efficiency and electrical power of the installation by increasing the degree of utilization of the absorption refrigeration machine.

The task is achieved as follows.

Compressed atmospheric air and/or fuel is burned in a combustion chamber and the heat of combustion products is converted into mechanical energy using a heat engine. Mechanical energy is converted into electrical energy in an electric generator. The thermal energy removed from the heat engine is used to supply heat to consumers and to be converted into cold energy in an absorption refrigeration machine to supply refrigeration to consumers. During periods of incomplete loading of the refrigeration machine, excess refrigeration capacity is used to cool the atmospheric air before compression.

The drawing shows a diagram of one of the possible installations with which the described method can be implemented.

Contains the following elements: 1 - air compressor, 2 - combustion chamber, 3 - gas turbine, 4 - heat exchanger for cooling turbine disks and blades, 5 - heat exchanger for the turbine lubrication system, 6 - flue gas heat exchanger, 7 - heat exchanger for the consumer heat supply system, 8 - air-water heat exchanger, 9 - pump cooling circuit, 10 - pump, 11 - absorption refrigeration machine, 12 - heat consumer, 13 - electric generator, 14 - cold consumer, 15 - hot water pipeline, 16 - chilled water pipeline, 17 - cooling tower of the refrigeration machine, 18 - return water supply pump (cooling) refrigerator, 19 - room, 20 - dry cooling tower of the trigeneration plant.

The method of operation of the combined production of electricity, heat and cold is carried out as follows

In compressor 1, the process of compressing atmospheric air occurs. From compressor 1, air enters combustion chamber 2, where sprayed fuel is continuously supplied under pressure through nozzles. From combustion chamber 2, combustion products are sent to turbine 3, in which the energy of combustion products is converted into mechanical energy of shaft rotation. In the electrical generator 13 this mechanical energy is converted into electrical energy. The thermal energy removed from the gas turbine through the heat exchangers of the lubrication system 5, the cooling system of the disks and blades 4 and from the exhaust gases 6 is transferred through the pipeline 15 to the heat exchanger 7 to supply consumers 12 with heat during the cold season. During the warm period, part of the thermal energy is used to supply heat to consumers, and the other part of the energy is transferred to the absorption refrigerator 11, which converts thermal energy into cold energy used to supply consumers with cold 14. Water cooled in the heat exchanger 7 is transferred by pump 9 for heating to heat exchangers 4 , 5, 6. In the absence of a need for thermal energy, excess heat is removed through dry coolers 20 into the atmosphere. During operation of the refrigeration machine 11, thermal energy is supplied to the generator and to the evaporator, while heat is removed in the absorber and condenser. To remove heat into the atmosphere, a circulating water supply circuit is used, which includes a cooling tower 17 and a pump 18. During the period of incomplete loading of the absorption refrigerator 11, the cooled water is transferred through the pipeline 16 to the air-water heat exchanger 8, located outside the room 19, for pre-cooling of the atmospheric air, supplied to compressor 1 to compress atmospheric air and supply it to combustion chamber 2, and water heated in heat exchanger 8 is transferred by pump 10 to 11 for cooling.

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The technical result that can be obtained by implementing the invention is to increase the degree of utilization of the absorption refrigeration machine due to cooling during the period of incomplete loading of atmospheric air before its compression. Pre-cooling of atmospheric air by reducing the compression work allows reducing fuel consumption in a heat engine, increasing the efficiency and electrical power of the installation.

List of sources used

1. Patent 2815486 (France), publ. 04/19/2002, IPC F01N 5/02-F02B 63/04; F02G 5/02; F25B 27/00; F25B 30/04; F01N 5/00; F02B 63/00; F02G 5/00; F25B 27/00; F25B 30/00; (IPC 1-7): H02K 7/18; F01N 5/02; F02B 63/04; F02G 5/02; F25B 27/02.

2. Patent 2005331147 (Japan), publ. 02.12.2005, MPK F25B 27/00; F25B 25/02; F25B 27/02; F25B 27/00; F25B 25/00; F25B 27/02; (GRS1-7): F25B 27/00; F25B 25/02; F25B 27/02.

3. Patent 20040061773 (Korea), publ. 07/07/2004, manual gearbox F02G 5/00; F02G 5/00; (IPC 1-7): F02G 5/00.

4. Patent 8246899 (Japan), publ. 09.24.1996, IPC F02C 3/22; F01K 23/10; F02C 6/00; F02C 7/143; F25B 15/00; F02C 3/20; F01K 23/10; F02C 6/00; F02C 7/12; F25B 15/00; (IPC1-7): F02C 7/143; F02C 3/22; F02C 6/00; F25B 15/00.

Claim

A method for the combined production of electricity, heat and cold, including compression of atmospheric air and/or fuel with their subsequent combustion in a combustion chamber and conversion of the heat of combustion products into mechanical energy using a heat engine, conversion of mechanical energy into electrical energy in an electric generator, transfer of part of the thermal energy, removed from the heat engine, for conversion in an absorption refrigeration machine into cold energy, used at least to cool the atmospheric air before its compression, characterized in that part of the thermal energy removed from the heat engine is used to supply heat to consumers, and converted into In an absorption refrigeration machine, thermal energy into cold energy is used to supply cold to consumers, and if excess cold energy occurs during periods of incomplete loading of the absorption refrigeration machine, it is used to cool the atmospheric air before compression.

Inventor's name: Bazhenov Alexander Ivanovich (RU), Mikheeva Elena Vladimirovna (RU), Khlebalin Yuri Maksimovich (RU)
Patent owner's name: State educational institution higher vocational education Saratov State Technical University(GOU VPO SSTU)
Postal address for correspondence: 410054, Saratov, st. Politekhnicheskaya, 77, SSTU (patent and licensing department)
Patent start date: 14.05.2009

Trigeneration is the combined production of electricity, heat and cold. The cold is produced by an absorption refrigeration machine that consumes thermal energy rather than electrical energy. Trigeneration is beneficial because it makes it possible to effectively use recycled heat not only in winter for heating, but also in summer for air conditioning or for technological needs. This approach allows the generating plant to be used all year round.

Trigeneration and industry

In the economy, in particular in the food industry, there is a need for cold water with a temperature of 8-14 ° C, used in technological processes. At the same time, in the summer, the temperature of the river water is at the level of 18-22 ° C (breweries, for example, use cold water to cool and store the finished product; on livestock farms, water is used to cool milk). Frozen food producers operate in temperatures ranging from -18°C to -30°C year-round. Applying trigeneration, cold can be used in various air conditioning systems.

Energy supply concept - trigeneration

During construction shopping center in the Moscow region, with a total area of ​​95,000 m², it was decided to install a cogeneration plant. The project was implemented in the late 90s. Energy supply shopping complex are carried out by four gas piston engines with an electrical power of 1.5 MW and a thermal power of 1.8 MW. Gas piston units operate on natural gas. The coolant is water heated to 110 °C. Hot water is used both directly for heating and for heating air coming from outside. Gas piston engines are equipped with mufflers and CO 2 neutralizers.

The energy supply concept uses the principle trigeneration. Electricity, heat and cold are produced together. During the warm season, the heat produced by the cogeneration unit can be utilized by an absorption refrigeration machine to cool the indoor air. Thus, the cogeneration plant produces heat or cold, depending on the time of year, maintaining the temperature in the rooms constant. This is especially important for storing furniture.

Trigeneration is provided by two bromine-lithium absorption refrigeration machines, each with a power of 1.5 MW. The cost of fuel consumed by the installations in 2002 was several times less than the cost of purchasing heat and electricity from the monopoly state company. In addition, the cost of connecting to city networks is in many cases comparable to the cost of the installations themselves and is equal to ~$1,000/kW.

Trigeneration - specifics

A special feature of an absorption refrigeration unit is the use of a thermochemical compressor rather than a mechanical one to compress refrigerant vapors. As a working fluid for absorption plants, a solution of two working fluids is used, in which one working fluid is refrigerant, and the other - absorbent. One of the working fluids, acting as a refrigerant, must have low temperature boiling and dissolve or be absorbed by the working fluid, which can be either liquid or solid. The second substance that absorbs (absorbs) the refrigerant is called an absorbent.

The independent energy company “New Generation” is ready, at its own expense, to install a 6.4 MW gas piston cogenerator power plant at your enterprise within 5–6 months, produced by MAN B&W Diesel AG.

The invention relates to thermal power engineering. The method for the combined production of electricity, heat and cold includes the conversion of the heat of combustion products into mechanical energy using a heat engine, the conversion of mechanical energy into electrical energy in an electric generator, the transfer of coolant heated in the cooling circuit of the heat engine and exhaust gases using heat exchangers of at least two heating stages, for heating, hot water supply and ventilation and for obtaining cold in an absorption refrigeration machine. Part of the coolant is diverted for the purposes of hot water supply, heating and ventilation before the heat exchangers of the second and/or subsequent heating stages, depending on the required temperature of the coolant in the hot water supply, heating and ventilation systems. The remaining part of the coolant is supplied after the heat exchanger of the last heating stage into the absorption refrigeration machine. The proposed method allows you to increase the refrigeration coefficient and the production of AHM cold. 2 ill.

Drawings for RF patent 2457352

The invention relates to thermal power engineering and can be used in the combined production of heat, cold and electricity.

There is a known method of operation of a mobile unit for the combined production of electricity, heat and cold, in which a generator converts the mechanical energy of a rotating engine shaft into electricity, the exhaust gases passing through a heat exchanger give off heat to a coolant fluid for heat supply during the heating season or are used in an absorption refrigeration machine for cold supply in summer period.

The disadvantages of this method of operation of the installation include low efficiency associated with the release of a significant part of unused thermal energy into the atmosphere.

There is also a known method of operation of an installation in which an internal combustion engine produces useful energy, converted into electrical energy using an electric generator; a second internal combustion engine is used to drive a compressor of a refrigeration machine that produces cold during the warm season. Heat recovered from the engine jacket and exhaust gases is used to supply heat to consumers during the cold season.

The disadvantages of the method of operation of this installation are the incomplete use of waste heat from internal combustion engines, additional fuel costs for operating the second internal combustion engine used to drive the compressor of the refrigeration machine.

There is a known method of operation of an installation that simultaneously supplies heat/cold and electricity, in which heat supply in the cold period is carried out by recycling the heat of exhaust gases and coolant of an internal combustion engine, the mechanical energy of the rotating shaft of the engine is converted into electricity, cold is generated in the warm period of the year in compression refrigeration machine.

The disadvantages of the method of operation of this installation include low efficiency due to insufficient use of waste heat from the internal combustion engine, and significant energy costs for operating the compressor of the refrigeration machine.

The closest technical solution (prototype) is the method of operation of an installation for generating electricity, heat and cold, in which a heat engine produces mechanical work that is converted into electrical energy using an electric generator. The waste heat of lubricating oil, coolant and exhaust gases removed through the heat exchangers of the first, second and third heating stages from the heat engine is utilized to supply heat to consumers. During the warm season, the recovered heat is partially used to provide consumers with hot water, and partially supplied to an absorption refrigeration machine to provide cold air conditioning systems.

However, this technical solution characterized by a relatively low temperature of the coolant (80°C) supplied from the heat engine, which leads to a decrease in the coefficient of performance and refrigerating power of the absorption refrigeration machine.

The objective of the invention is to increase the coefficient of performance and refrigeration capacity by increasing the temperature of the coolant supplied to the absorption refrigeration machine.

The task is achieved as follows.

In a method for the combined production of electricity, heat and cold, including converting the heat of combustion products into mechanical energy using a heat engine, converting mechanical energy into electrical energy in an electric generator, transferring coolant heated in the cooling circuit of a heat engine and exhaust gases using heat exchangers, at least two stages of heating, for heating, hot water supply and ventilation and for obtaining cold in an absorption refrigeration machine, part of the coolant is allocated for the purposes of hot water supply, heating and ventilation before the heat exchangers of the second and/or subsequent heating stages, depending on the required temperature of the coolant in hot water supply systems , heating and ventilation, the remaining part of the coolant is supplied after the heat exchanger of the last heating stage into the absorption refrigeration machine.

Due to the removal of part of the coolant for the needs of hot water supply, heating and ventilation, the mass flow rate of the heated coolant supplied to the heat exchangers of subsequent heating stages will decrease, which means, other things being equal, without increasing the heating surface area, the temperature of the heated coolant leaving these heat exchangers increases. Increasing the temperature of the coolant discharged into the absorption refrigeration machine makes it possible to increase its refrigeration coefficient and, accordingly, its cooling capacity.

The proposed method for the combined production of electricity, heat and cold is illustrated in Figs. 1 and 2.

Figure 1 shows a diagram of one of the possible power plants with which the described method can be implemented.

Figure 2 shows the dependence of the relative cooling capacity of an absorption refrigeration machine on the temperatures of the cooled, cooling and heating water.

The power plant contains the following elements: 1 - air compressor, 2 - combustion chamber, 3 - gas turbine, 4 - heat exchanger for the turbine lubrication system (first heating stage), 5 - heat exchanger for cooling turbine disks and blades (second heating stage), 6 - heat exchanger exhaust (exhaust) gases (third stage of heating), 7 - heat exchanger of the heat supply system (heating, ventilation of consumers), 8 - absorption refrigeration machine, 9 - heat consumer (heating and ventilation), 10 - cold consumer, 11 - hot water consumer, 12 - dry cooling tower of the power plant, 13 - cooling tower of the refrigeration machine, 14 - pump of the circulating water supply circuit of the refrigerator, 15 - pump of the cold supply circuit of consumers, 16 - pump of the hot water supply circuit of consumers, 17 - pump of the heat supply circuit (heating and ventilation), 18 - pump cooling circuit of the heat engine, 19 - electric generator, 20 - heat exchanger of the hot water supply system for consumers, 21, 22, 23 - pipelines for supplying the heating fluid to the heat exchanger of the hot water supply system (20), 24, 25, 26 - pipelines for supplying the heating fluid to the heat exchanger (7 ) heat supply systems (heating and ventilation), 27 - supply pipeline of the heating coolant of the absorption refrigeration machine, 28 - cooling circuit of the heat engine.

The installation method is as follows.

In compressor 1, the process of compressing atmospheric air occurs. From compressor 1, air enters combustion chamber 2, where sprayed fuel is continuously supplied under pressure through nozzles. From combustion chamber 2, combustion products are sent to gas turbine 3, in which the energy of combustion products is converted into mechanical energy of shaft rotation. In the electrical generator 19 this mechanical energy is converted into electrical energy. Depending on the heat load, the installation operates in one of three modes:

Mode I - with heat release for heating, ventilation and hot water supply;

Mode II - with heat supplied to hot water supply and absorption refrigerator;

III mode - with heat supply for heating, ventilation and hot water supply and for absorption refrigerator;

In mode I (during the cold season), the coolant is heated in the heat exchanger of the lubrication system 4 (first heating stage), the heat exchanger of the disk and blade cooling system 5 (second heating stage) and the flue gas heat exchanger 6 (third heating stage) through a pipeline 26 is supplied to the heat exchanger 7 for heating and ventilation of consumers 9 and through pipelines 21, and/or 22, and/or 23 to the hot water supply heat exchanger 20.

In mode II (during the warm period of the year), depending on the required temperature in the hot water supply system, part of the coolant is removed after the heat exchanger of the lubrication system 4 (the first heating stage) and/or the heat exchanger of the disk and blade cooling system 5 (the second heating stage) and/or the heat exchanger exhaust (exhaust) gases 6 (third stage of heating) through pipelines 21, and/or 22, and/or 23 to the hot water supply heat exchanger 20, and the remaining coolant through pipeline 27 is supplied to the absorption refrigeration machine 8 to produce cold used for cooling consumers 10.

In mode III (in the autumn-spring period), depending on the required temperatures in the hot water supply, heating and ventilation systems, part of the coolant is removed after the heat exchanger of the lubrication system 4 (first stage of heating), and/or the heat exchanger of the cooling system of disks and blades 5 (second stage heating), and/or heat exchanger of flue (exhaust) gases 6 (third stage of heating) through pipelines 21, and/or 22, and/or 23 to hot water heat exchanger 20, part of the coolant after the heat exchanger of lubrication system 4 (first stage of heating), heat exchanger of the cooling system of disks and blades 5 (second stage of heating) and/or heat exchanger of flue gases 6 (third stage of heating) through pipelines 24, and/or 25, and/or 26 is supplied to heat exchanger 7 for heating and ventilation of consumers 9 , the part of the coolant remaining in the cooling circuit of the heat engine 28 is supplied through pipeline 27 to the absorption refrigeration machine 8 to obtain cold used for cooling consumers 10. The coolant cooled in heat exchangers 7, 8 and 20 is transferred by pump 18 for heating to heat exchangers 4, 5 , 6. If there is no need for thermal energy, excess heat is removed through dry cooling towers 12 into the atmosphere.

For example, when the installation is operating in mode II, in the case of coolant selection for hot water supply after the heat exchanger of the third heating stage, coolant with a temperature of 103.14°C is supplied to the absorption refrigeration machine through pipeline 27.

In the case of selecting 30% of the coolant for the purpose of hot water supply, after the second stage heat exchanger, coolant with a temperature of 112.26 ° C is supplied to the absorption refrigeration machine, which increases the cooling capacity (according to Fig. 2) by 22%.

In the case of selecting 30% of the coolant for the purpose of hot water supply, after the first stage heat exchanger, coolant with a temperature of 115.41 ° C is supplied to the absorption refrigeration machine, which increases the cooling capacity (according to Fig. 2) by 30%.

The technical result that can be obtained by implementing the invention is to increase the coefficient of performance and refrigeration power of an absorption refrigeration machine by increasing the temperature of the coolant removed from the engine cooling circuit. The use of a coolant with higher parameters, obtained as a result of reducing its average flow rate in the cooling circuit of a heat engine due to the removal of part of the coolant when it reaches the required temperature for heat supply needs, makes it possible to increase the refrigerating capacity of an absorption refrigeration machine.

Information sources

1. Patent No. 2815486 (France), publ. 04/19/2002, IPC F01N 5/02-F02B 63/04; F02G 5/02; F25B 27/00; F25B 30/04; F01N 5/00; F02B 63/00; F02G 5/00; F25B 27/00; F25B 30/00.

2. Patent No. 2005331147 (Japan), publ. 02.12.2005, MPK F25B 27/00; F25B 25/02; F25B 27/02; F25B 27/00; F25B 25/00; F25B 27/02.

3. Patent No. 20040061773 (Korea), publ. 07/07/2004, manual gearbox F02G 5/00; F02G 5/00.

4. Patent No. 20020112850 (USA), publ. 08/22/2002, IPC F01K 23/06; F02G 5/04; F24F 5/00; F01K 23/06; F02G 5/00; F24F 5/00.

CLAIM

A method for the combined production of electricity, heat and cold, including the conversion of the heat of combustion products into mechanical energy using a heat engine, the conversion of mechanical energy into electrical energy in an electric generator, the transfer of coolant heated in the cooling circuit of a heat engine, and exhaust gases using heat exchangers of at least two heating stages, for heating, hot water supply and ventilation and for obtaining cold in an absorption refrigeration machine, characterized in that part of the coolant is allocated for the purposes of hot water supply, heating and ventilation before the heat exchangers of the second and/or subsequent heating stages, depending on the required coolant temperature in hot water supply, heating and ventilation systems, the remaining part of the coolant is supplied after the heat exchanger of the last heating stage into the absorption refrigeration machine.