Thermoelectric decoupling system for back pressure unit coupling compressed air energy storage and operation method

Abstract

The invention discloses a thermoelectricity decoupling system for back pressure unit coupling compressed air energy storage and an operation method, and belongs to the technical field of back pressure unit thermoelectricity decoupling. According to the system, a thermoelectricity unit and an air energy storage system are communicated, two heaters are arranged on the two sides of an air storage tank respectively, one heater heats heat supply network return water when heat is much and electricity is little, and the other heater heats heat supply network return water when heat is much and electricity is little; one heater heats air through steam when electricity is more and heat is less, and the energy of the air is converted into electric energy which is converged into a station service power system. When back pressure electromechanical and thermal load adjustment is carried out, on the basis that the back pressure unit preferentially meets the thermal load, electrical load adjustment is achieved by starting and stopping the compressed air energy storage system. Heat supply network return water absorbs compression heat in the compressed air process, waste heat recycling is achieved, the external heat supply load of the unit is increased, when the compressed air energy storage system releases energy, high-pressure air in the air storage tank is heated through unit steam extraction, the expansion power capability of the high-pressure air is improved, and the on-grid electricity of the unit is increased.

Description

Technical Field

[0001] The present invention belongs to the technical field of thermoelectric decoupling of back pressure units, and in particular relates to a thermoelectric decoupling system of a back pressure unit coupled with compressed air energy storage and an operating method thereof. Background Art

[0002] In recent years, with the transformation of the global energy structure and the improvement of environmental awareness, new energy power generation technologies such as wind energy and solar energy have developed rapidly, and their installed capacity has achieved rapid growth worldwide. These new energy sources, with their clean and renewable characteristics, have become an important substitute for traditional fossil energy, and are of great significance for promoting green energy transformation and reducing greenhouse gas emissions.

[0003] However, the rapid development of renewable energy power generation has also brought a series of challenges. In some areas, the installed capacity of renewable energy has far exceeded the absorption capacity of local power grids, leading to an imbalance in power supply and demand. At the same time, renewable energy such as wind energy and solar energy are intermittent and volatile, and their output power is affected by weather conditions, time changes and other factors, making it relatively difficult to regulate and control. When these renewable energy sources are connected to the grid on a large scale, they will pose a threat to the safe and stable operation of the power grid, increasing the complexity of grid dispatching and management.

[0004] In order to meet the challenges brought by renewable energy generation, the power grid has higher and higher requirements for peak load regulation on the power generation side. Peak load regulation refers to the flexible adjustment of the output power of the generator according to the changes in the power grid load to maintain the stable operation of the power grid. In this context, back pressure units, as an important form of cogeneration, have also been given new roles and missions. Many regions have begun to require back pressure units to have higher flexibility and participate in power peak load regulation and spot market transactions to adapt to the volatility and uncertainty of renewable energy generation.

[0005] However, at present, traditional back-pressure cogeneration units usually adopt the "heat-to-electricity" operation mode. In this mode, the unit's power generation is mainly limited by the heat load, and the heat supply flexibility is poor. When the heat load is stable, this operation mode can ensure the stable operation and efficient utilization of the unit; but when the heat load fluctuates greatly or the power generation needs to be flexibly adjusted, the limitations of this method are obvious. Therefore, traditional back-pressure units can only be used in application scenarios with stable heat loads, and it is difficult to meet the higher requirements for grid peak regulation and flexibility in the context of renewable energy power generation. Summary of the invention

[0006] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide a thermoelectric decoupling system and operation method of a back-pressure unit coupled with compressed air energy storage, so as to solve the problem that the thermal power units in the prior art have poor heating flexibility and are difficult to adapt to the peak-shaving needs of the power grid. In order to achieve the above object, the present invention adopts the following technical solutions: A thermoelectric decoupling system of a back pressure unit coupled with compressed air energy storage, comprising a back pressure unit, a heat network condenser, a first heat exchanger, an air storage tank, a second heat exchanger, an air compressor and a turbine; The exhaust steam outlet of the back compressor is respectively connected to the hot end inlet of the heat network condenser and the hot end inlet of the second heat exchanger, and the hot end outlet of the heat network condenser and the hot end outlet of the second heat exchanger are both connected to the deaerator; The power output end of the back compressor is connected to a first generator, the first generator is connected to an air compressor, the air compressor is connected to a hot end inlet of a first heat exchanger, the hot end outlet of the first heat exchanger is connected to an inlet of an air storage tank; the outlet of the air storage tank is connected to a cold end inlet of a second heat exchanger, and the cold end outlet of the second heat exchanger is connected to a turbine; The return water of the heating network is connected to the cold end inlet of the heating network condenser and the cold end inlet of the first heat exchanger respectively. The cold end outlet of the heating network condenser is connected to the heating network water supply pipeline, and the cold end outlet of the first heat exchanger is connected to the heating network water supply pipeline.

[0007] A further improvement of the present invention is: Preferably, the first generator is connected via a high-voltage transformer and an air compressor.

[0008] Preferably, a branch is provided on the pipeline connecting the exhaust steam outlet of the back compressor and the hot end inlet of the second heat exchanger, and the branch is connected to the deaerator.

[0009] Preferably, the power output shaft of the turbine is connected to a second generator.

[0010] Preferably, the second generator is connected to the plant power system via a transformer.

[0011] Preferably, a fourth electric gate valve is provided on the connecting pipeline between the heat network return water and the cold end inlet of the heat network condenser, and a fifth electric gate valve is provided on the connecting pipeline between the heat network return water and the cold end inlet of the first heat exchanger.

[0012] Preferably, a third electric gate valve is provided between the cold end outlet of the heating network condenser and the heating network water supply pipeline, and a sixth electric gate valve is provided between the cold end outlet of the first heat exchanger and the heating network water supply pipeline.

[0013] Preferably, a seventh electric gate valve is provided between the first heat exchanger and the air storage tank, and an electric regulating valve is provided between the air storage tank and the second heat exchanger.

[0014] An operating method of the thermoelectric decoupling system of the back pressure unit coupled with compressed air energy storage, when the thermoelectric decoupling system is in a low-electricity and high-heat operating condition, the electric energy generated by the operation of the back pressure unit is used to drive the air compressor to compress air into a high-temperature and high-pressure state through the first generator, and the compressed air in the high-temperature and high-pressure state is transmitted to the first heat exchanger; The exhaust steam of the back pressure machine heats the return water of the heat network through the heat network condenser, and the first heat exchanger heats the return water of the heat network through the compressed air in a high temperature and high pressure state, and the cooled air enters the air storage tank.

[0015] An operating method for the above-mentioned thermoelectric decoupling system of the back pressure unit coupled with compressed air energy storage, when the thermoelectric decoupling system is in a condition of more electricity and less heat, the air in the air storage tank is heated by exhaust steam in the second heat exchanger, and the heated air expands in the turbine to do work; the exhaust steam of the back pressure machine heats the return water of the heat network through the heat network condenser.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The present invention discloses a thermoelectric decoupling system of a back-pressure unit coupled with compressed air energy storage, which connects a thermoelectric unit with an air energy storage and release system, and arranges two heaters on both sides of the air storage tank. One heater heats the return water of the heating network when there is more heat and less electricity, and the other heater heats the air through steam when there is more electricity and less heat, converts the energy of the air into electrical energy, and merges it into the plant power system. The present invention can realize a large-scale adjustment of the back-pressure electromechanical and thermal loads by adding a compressed air energy storage system, and realizes thermoelectric decoupling to the greatest extent. When adjusting the back-pressure electromechanical and thermal loads, the electrical load adjustment is realized by starting and stopping the compressed air energy storage system, all based on the priority of satisfying the thermal load of the back-pressure unit. The return water of the heating network absorbs the compression heat in the process of compressing the air, realizes the recycling of waste heat, and increases the external heating load of the unit. When the compressed air energy storage system releases energy, the high-pressure air in the air storage tank is heated by the steam extraction of the unit, so as to improve the expansion work capacity of the high-pressure air and increase the online power of the unit. In order to improve the heating flexibility of a back pressure cogeneration unit and realize thermal-electric decoupling to the greatest extent, the present invention proposes a thermal-electric decoupling system of a back pressure unit coupled with compressed air energy storage. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram of a thermoelectric decoupling system of a back pressure unit coupled with compressed air energy storage; In the figure: 1. back pressure machine; 2. heat network condenser; 3. condensate pump; 4. deaerator; 5. air compressor; 6. first heat exchanger; 7. air storage tank; 8. second heat exchanger; 9. turbine; 10. high-voltage power plant transformer; 11. transformer; 12. first electric gate valve; 13. second electric gate valve; 14. third electric gate valve; 15. fourth electric gate valve; 16. fifth electric gate valve; 17. sixth electric gate valve; 18. seventh electric gate valve; 19. electric regulating valve; 20. first generator; 21. second generator. DETAILED DESCRIPTION

[0018] The present invention is further described in detail below in conjunction with the accompanying drawings: Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0019] As mentioned in the background technology, the installed capacity of new energy power generation such as wind energy and solar energy has grown rapidly. The installed capacity of new energy in some regions far exceeds the absorption capacity of other regions. At the same time, due to the intermittent and volatile characteristics of wind energy and solar energy, it is difficult to regulate and control. Large-scale grid connection will affect the safe operation of the power grid. Therefore, the peak-shaving requirements on the power generation side of the power grid are getting higher and higher. Many regions have also put forward corresponding flexibility requirements for backpressure units, and backpressure units also participate in power peak-shaving and spot market transactions. However, at present, backpressure cogeneration units usually operate in a "heat-based electricity" mode, which will cause backpressure cogeneration units to face two extreme working conditions: 1) less electricity and more heat; 2) more electricity and less heat. Most backpressure units receive industrial steam supply and residential heating steam supply at the same time, which often leads to the inability to meet the needs of steam supply and residential heating steam at the same time under certain extreme working conditions.

[0020] In order to make the back pressure machine cogeneration unit better adapt to these two working conditions and realize thermoelectric decoupling to the greatest extent, the present invention discloses a thermoelectric decoupling system of a back pressure unit coupled with compressed air energy storage, which mainly includes a back pressure machine cogeneration system and a compressed air energy storage system.

[0021] The back pressure cogeneration system includes a back pressure machine 1, a heat network condenser 2, a condensate pump 3, a deaerator 4, a first heat exchanger 6 and a second heat exchanger 8. The compressed air energy storage system includes an air compressor 5, an air storage tank 7, a turbine 9 and a transformer 11.

[0022] The return water from the heating network is divided into two branches, one leading to the heating network condenser 2, and the other leading to the first heat exchanger 6. After being heated in these two devices, the return water from the heating network is combined and returned to the heating network supply water.

[0023] There are three exhaust steam outlets of the back compressor 1, namely the industrial steam supply pipeline, the pipeline to the heat network condenser 2, and the pipeline to the hot end inlet of the second heat exchanger 8. The power output end of the back compressor 1 is connected to the first generator 20, and the first generator 20 is connected to the booster station. The first generator 20 is also connected as the air compressor 5 in the power and air energy storage system.

[0024] The hot end inlet of the heat network condenser 2 is connected to the exhaust steam outlet of the back pressure machine 1, the hot end outlet is connected to the deaerator 4 through the condensate pump 3, the cold end inlet of the heat network condenser 2 is connected to the heat network return water, and the cold end outlet is connected to the heat network supply water.

[0025] The inlet of the deaerator 4 is simultaneously connected to the exhaust steam outlet of the back pressure machine 1 , the heat source outlet of the heat network condenser 2 , and the hot end outlet of the second heat exchanger 8 .

[0026] In the air energy storage system, the inlet of the air compressor 5 is air, and the power source of the air compressor 5 is an electric motor, which is connected to the high-voltage transformer 10, and the high-voltage transformer 10 is connected to the first generator 20. The high-voltage transformer is a transformer connected to the generator outlet for the power supply of the power plant. It is a special transformer for the high-voltage system of the power plant to convert the low-voltage system to the power supply of the power plant. When the heating network needs more heat for water supply, the high-voltage transformer 10 can convert the heat provided by the back pressure machine 1 into electric energy that can be used by the air compressor 5, and convert this part of the energy into high-temperature and high-pressure steam.

[0027] The air is compressed into high-temperature and high-pressure steam in the air compressor 5 and connected to the hot end inlet of the first heat exchanger 6. The hot end outlet of the first heat exchanger 6 is connected to the air storage tank 7. The outlet of the air storage tank 7 is connected to the cold end inlet of the second heat exchanger 8. The cold end outlet of the second heat exchanger 8 is connected to the turbine 9. The power output end of the turbine 9 is connected to the second generator 21. The second generator 21 is connected to the plant power system through the transformer 11.

[0028] The cold end inlet of the first heat exchanger 6 is connected to the return water of the heating network, and the cold end outlet is connected to the water supply of the heating network. The hot end inlet of the second heat exchanger 8 is connected to the exhaust steam outlet of the back pressure machine 1, and the hot end outlet is connected to the inlet of the deaerator 4.

[0029] A fourth electric gate valve 15 is provided on the connecting pipeline between the heat network return water and the cold end inlet of the heat network condenser 2, a fifth electric gate valve 16 is provided on the connecting pipeline between the heat network return water and the cold end inlet of the first heat exchanger 6, a third electric gate valve 14 is provided between the cold end outlet of the heat network condenser 2 and the heat network water supply pipeline, and a sixth electric gate valve 17 is provided between the cold end outlet of the first heat exchanger 6 and the heat network water supply pipeline. The arrangement of this part of the structure enables the heat network return water to provide different heat sources according to different heat supply requirements. When more heat is needed, it is heated by air energy and unit heat, and the power source of the air energy also comes from the thermal power unit; when the heat network return water does not need too much heat, the heat network return water is only heated by exhaust steam, and the excess heat of the thermal power unit is transferred to compressed air through the second heat exchanger, and electric energy is generated by compressed air and fed into the power grid.

[0030] Furthermore, a second electric gate valve 13 is provided on the pipeline connecting the exhaust steam outlet of the back pressure machine 1 and the hot end inlet of the second heat exchanger 8, and a first electric gate valve 12 is provided on the branch of the pipeline connecting the exhaust steam outlet of the back pressure machine 1 and the hot end inlet of the second heat exchanger 8. Both electric gate valves are located downstream of the branch end, so that the two branches can be controlled separately. This structural setting enables the exhaust steam to directly enter the deaerator 4 and return to the boiler when there is less electricity and more heat, and this part of the air can be heated through the second heat exchanger 8 when there is more electricity and less heat.

[0031] Furthermore, a seventh electric gate valve 18 is provided between the first heat exchanger 6 and the air storage tank 7, and an electric regulating valve 19 is provided between the air storage tank 7 and the second heat exchanger 8, corresponding to the energy storage and energy release processes of the air respectively.

[0032] The operation process of the above system is: Case 1: Less electricity and more heat: Under this condition, priority is given to external heat supply. Since the back pressure unit operates in a "heat-based electricity" mode, the electricity load is also high under high heat load conditions. In order to cope with the peak load of electricity and spot market transactions, the compressed air energy storage system is started, and the generator outlet bus in the back pressure power generation system is connected to the transformer to supply power to the air compressor, reducing the online power of the back pressure power generation system and increasing the deep regulation amplitude; at the same time, the air compressor compresses the air to a high pressure and high temperature state, and the high pressure and high temperature air enters the first heat exchanger to heat the circulating water of the heat network, further increasing the external heat supply load. The cooled high pressure air is stored in the air storage tank, and the energy storage process of the compressed air energy storage system is completed.

[0033] The specific operation is to close the electric gate valve 13 and the electric regulating valve 19, open the first electric gate valve 12, the third electric gate valve 14, the fourth electric gate valve 15, the fifth electric gate valve 16, the sixth electric gate valve 17 and the seventh electric gate valve 18, and the energy release part of the compressed air energy storage system does not work. Under this working condition, priority is given to external heat supply. The exhaust steam of the back pressure machine 1 enters the heat network condenser 2 to heat the heat network circulating water return water, condenses into drainage, and enters the deaerator 4 through the condensate pump 3. The heat network circulating water return water is divided into two streams, one enters the heat network condenser 2 to be heated; the other enters the first heat exchanger 6 in the compressed air energy storage system, exchanges heat with the high-pressure and high-temperature air, and then merges with the heat network circulating water at the outlet of the heat network condenser 2, and is sent to the user side for heating. In the back pressure generator power generation system, the generator outlet bus is connected to the transformer 10 to supply power to the air compressor 5, driving the air compressor 5 to compress the air to a high temperature and high pressure state. The high temperature and high pressure air enters the first heat exchanger 6 to heat the circulating water return water of the heat network. After cooling, the high pressure air is stored in the air storage tank 7, and the energy storage process of the compressed air energy storage system is completed.

[0034] Case 2: more electricity and less heat. Under this condition, priority is given to external heat supply. Since the back-pressure unit operates in a "heat-to-electricity" mode, the electricity load is also low under low heat load conditions. In order to cope with the high electricity load during the evening peak period, the compressed air energy storage system is started. The high-pressure air from the air storage tank enters the second heat exchanger, which is heated by the extraction steam from the unit. The extraction steam is condensed into drain and returned to the deaerator. The heated high-pressure and high-temperature air enters the turbine to expand and do work, driving the generator to generate electricity. The generator outlet bus is connected to the plant power system through a transformer, replacing part of the plant power, which can further increase the amount of power online.

[0035] The specific operation is to close the third electric gate valve 14, the fourth electric gate valve 15, the fifth electric gate valve 16, the sixth electric gate valve 17 and the seventh electric gate valve 18, open the electric gate valve 13 and the electric regulating valve 19, and the energy storage part of the compressed air energy storage system does not work. Under this working condition, priority is given to external heat supply. The exhaust steam of the back pressure machine 1 enters the heat network condenser 2 to heat the heat network circulating water return water, condenses into drainage, and enters the deaerator 4 through the condensate pump 3. Start the compressed air energy storage system. The high-pressure air from the air storage tank 7 enters the second heat exchanger 8, and the second heat exchanger 8 is heated by the extraction steam from the unit. The extraction steam is condensed into drainage and returned to the deaerator 4. The heated high-pressure and high-temperature air enters the turbine 9 to expand and work, driving the generator to generate electricity. The generator outlet bus is connected to the plant power system through the transformer 11, receiving part of the plant power, which can further increase the amount of power on the grid.

[0036] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more. In the description of the present invention, the first feature "above" or "below" the second feature may include the first and second features being in direct contact, or the first and second features not being in direct contact but being in contact through another feature between them.

[0037] In the description of the present invention, “on”, “over” and “above” a first feature from a second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is horizontally higher than the second feature.

[0038] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0040] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

[0041] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A thermoelectric decoupling system of a back pressure unit coupled with compressed air energy storage, characterized in that: It comprises a back pressure machine (1), a heat network condenser (2), a first heat exchanger (6), an air storage tank (7), a second heat exchanger (8), an air compressor (5) and a turbine (9); The exhaust steam outlet of the back compressor (1) is respectively connected to the hot end inlet of the heat network condenser (2) and the hot end inlet of the second heat exchanger (8), and the hot end outlet of the heat network condenser (2) and the hot end outlet of the second heat exchanger (8) are both connected to the deaerator (4); The power output end of the back compressor (1) is connected to a first generator (20), the first generator (20) is connected to an air compressor (5), the air compressor (5) is connected to a hot end inlet of a first heat exchanger (6), the hot end outlet of the first heat exchanger (6) is connected to an inlet of an air storage tank (7); the outlet of the air storage tank (7) is connected to a cold end inlet of a second heat exchanger (8), and the cold end outlet of the second heat exchanger (8) is connected to a turbine (9); The heat network return water is respectively connected to the cold end inlet of the heat network condenser (2) and the cold end inlet of the first heat exchanger (6); the cold end outlet of the heat network condenser (2) is connected to the heat network water supply pipeline; and the cold end outlet of the first heat exchanger (6) is connected to the heat network water supply pipeline.

2. A thermoelectric decoupling system of a back pressure unit coupled with compressed air energy storage according to claim 1, characterized in that: The first generator (20) is connected to the air compressor (5) via a high-voltage transformer (10).

3. A thermoelectric decoupling system of a back pressure unit coupled with compressed air energy storage according to claim 1, characterized in that: A branch is provided on a pipeline connecting the exhaust steam outlet of the back compressor (1) and the hot end inlet of the second heat exchanger (8), and the branch is connected to the deaerator (4).

4. A thermoelectric decoupling system of a back pressure unit coupled with compressed air energy storage according to claim 1, characterized in that: The power output shaft of the turbine (9) is connected to a second generator (21).

5. A thermoelectric decoupling system of a back pressure unit coupled with compressed air energy storage according to claim 4, characterized in that: The second generator (21) is connected to the factory power system via a transformer (11).

6. A thermoelectric decoupling system of a back pressure unit coupled with compressed air energy storage according to claim 1, characterized in that: A fourth electric gate valve (15) is provided on a pipeline connecting the return water of the heating network and the cold end inlet of the heating network condenser (2), and a fifth electric gate valve (16) is provided on a pipeline connecting the return water of the heating network and the cold end inlet of the first heat exchanger (6).

7. A thermoelectric decoupling system of a back pressure unit coupled with compressed air energy storage according to claim 1, characterized in that: A third electric gate valve (14) is provided between the cold end outlet of the heating network condenser (2) and the heating network water supply pipeline, and a sixth electric gate valve (17) is provided between the cold end outlet of the first heat exchanger (6) and the heating network water supply pipeline.

8. The thermoelectric decoupling system of a back pressure unit coupled with compressed air energy storage according to claim 1, characterized in that: A seventh electric gate valve (18) is provided between the first heat exchanger (6) and the air storage tank (7), and an electric regulating valve (19) is provided between the air storage tank (7) and the second heat exchanger (8).

9. An operating method of the thermoelectric decoupling system of the back pressure unit coupled with compressed air energy storage according to claim 1, characterized in that: When the thermoelectric decoupling system is in a low-electricity and high-heat operating state, the electric energy generated by the operation of the back compressor (1) is used to drive the air compressor (5) through the first generator (20) to compress air into a high-temperature and high-pressure state, and the high-temperature and high-pressure compressed air is transmitted to the first heat exchanger (6); The exhaust steam of the back pressure machine (1) heats the return water of the heat network through the heat network condenser (2), and the first heat exchanger (6) heats the return water of the heat network through the compressed air in a high-temperature and high-pressure state, and the cooled air enters the air storage tank (7).

10. An operating method of the thermoelectric decoupling system of the back pressure unit coupled with compressed air energy storage according to claim 1, characterized in that: When the thermoelectric decoupling system is in a condition where there is more electricity and less heat, the air in the air storage tank (7) is heated by exhaust steam in the second heat exchanger (8), and the heated air expands in the turbine (9) to perform work; the exhaust steam from the back compressor (1) heats the return water of the heat network through the heat network condenser (2).

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