Combined cooling and power system of compressed air energy storage and compression absorption refrigeration

Abstract

The application provides a combined cooling and power cogeneration system of compressed air energy storage and compression absorption refrigeration, which comprises an energy storage system and a cooling system; the energy storage system comprises an air compression cooling module, a gas storage device, a first heat storage device, a second heat storage device, an air heating module and a power generation module; the cooling system comprises a generator module, a regenerator module, an absorber module, a condensing device and an evaporating device; the air compression cooling module, the gas storage device, the air heating module and the power generation module are sequentially connected; the first heat storage device, the air compression cooling module, the second heat storage device and the air heating module are sequentially connected; the second heat storage device, the generator module, the condensing device, the evaporating device and the absorber module are sequentially connected; and the second heat storage device, the generator module, the regenerator module, the absorber module, the air heating module and the power generation module are sequentially connected. The combined cooling and power cogeneration system solves the defect of low energy utilization rate of the existing adiabatic compressed air energy storage system and improves the system energy utilization rate.

Description

Technical Field

[0001] This invention relates to the field of compressed air energy storage technology, and in particular to a combined cooling and power system that integrates compressed air energy storage and compression absorption refrigeration. Background Technology

[0002] Thermal compressed air energy storage technology is an emerging energy storage technology. Its principle is mainly to use off-peak electricity or clean energy such as wind power and photovoltaic power that cannot be consumed to drive an electric motor to compress air into high-pressure air after passing through a compressor and storing it in an air storage tank.

[0003] In existing technologies, adiabatic compressed air energy storage systems add interstage heat exchangers between compressors to store the heat of compression generated during the compression process. This heat is then used to heat the air during the expansion and release process. During peak electricity demand periods, high-pressure air exits the storage tank, passes through the interstage heat exchangers, and heats the low-temperature air before driving the expander to perform work and power a generator. Because of the addition of interstage heat exchangers to absorb the heat of compression, adiabatic compressed air energy storage technology reduces the combustion of natural gas during the expansion process, thus reducing secondary carbon emissions. However, the system has the following drawbacks:

[0004] During compression, a large amount of compression heat absorbed and stored by the heat storage medium is used to heat the air during expansion discharge. However, the stored compression heat cannot be fully absorbed and utilized by the expanding air. The stored compression heat will remain in the high-temperature heat storage tank. This remaining compression heat needs to be cooled externally to ensure the cooling effect in the next cycle.

[0005] During compression, the absorbed heat will cause the temperature of the high-temperature heat transfer medium to exceed 400K. This part of the heat is only used to heat the air for expansion and power generation in the compressed air energy storage system. The system cannot recover and utilize this part of the heat energy.

[0006] During the expansion discharge process, the air that has completed its work in the high-pressure stage expander is often at a low temperature. However, if the system directly passes this low-temperature air into the next stage heat exchanger for reheating, it will not only increase the system's energy consumption but also reduce the cooling capacity of that portion of the gas. Waste.

[0007] That is, the existing adiabatic compressed air energy storage system has low energy utilization during operation. Summary of the Invention

[0008] This invention provides a combined cooling and power system that integrates compressed air energy storage and compression absorption refrigeration, in order to solve the technical defects of low energy utilization in existing adiabatic compressed air energy storage systems and improve the system's energy utilization rate.

[0009] This invention provides a combined cooling and power system integrating compressed air energy storage and compression absorption refrigeration, comprising an energy storage system and a cooling system:

[0010] The energy storage system includes an air compression cooling module, an air storage device, a first thermal storage device, a second thermal storage device, an air heating module, and a power generation module.

[0011] The cooling system includes a generator module, a regenerator module, an absorber module, a condenser device, and an evaporator device;

[0012] The air compression cooling module, the air storage device, the air heating module, and the power generation module are connected in sequence; the first heat storage device, the air compression cooling module, the second heat storage device, and the air heating module are connected in sequence; the second heat storage device, the generator module, the condenser device, the evaporator device, and the absorber module are connected in sequence; the second heat storage device, the generator module, the regenerator module, the absorber module, the air heating module, and the power generation module are connected in sequence.

[0013] According to the combined cooling and power system of compressed air energy storage and compression absorption refrigeration provided by the present invention, the generator module includes at least one generator, and when multiple generators are included, all generators are connected in sequence.

[0014] The regenerator module includes regenerators that correspond one-to-one with the number of generators, and the regenerators are connected to the generators in a one-to-one correspondence.

[0015] The absorber module includes at least one absorber, and when multiple absorbers are included, all absorbers are connected in sequence.

[0016] According to the combined cooling and power system of compressed air energy storage and compressed absorption refrigeration provided by the present invention, the absorber module is connected to each of the regenerators respectively; a booster pump is provided between the absorber module and each of the regenerators respectively.

[0017] According to the combined cooling and power system of compressed air energy storage and compression absorption refrigeration provided by the present invention, the air compression cooling module includes at least one stage of air compression cooling unit, and each stage of the air compression cooling unit includes an air compression device and an air cooling device connected in sequence.

[0018] When multiple stages of the air compression cooling unit are included, all the air compression cooling units are connected in sequence; the air storage device is connected to the air cooling device in the last stage of the air compression cooling unit; the first heat storage device is connected to the air cooling device in each stage of the air compression cooling unit, and the second heat storage device is connected to the air cooling device in each stage of the air compression cooling unit.

[0019] According to the combined cooling and power system of compressed air energy storage and compression absorption refrigeration provided by the present invention, the air compression cooling module further includes an electric motor for driving the air compression device.

[0020] According to the combined cooling and power system of compressed air energy storage and compressed absorption refrigeration provided by the present invention, the air heating module includes at least one air heating device. When multiple air heating devices are included, the second heat storage device is connected to each of the air heating devices respectively, and the absorber module is connected to each of the air heating devices respectively.

[0021] According to the combined cooling and power generation system of compressed air energy storage and compression absorption refrigeration provided by the present invention, the power generation module includes an expander and a power generation device. The expander is connected to the power generation device. The number of expanders and air heating devices are in one-to-one correspondence, and the expanders and air heating devices are connected in one-to-one correspondence.

[0022] According to the combined cooling and power system of compressed air energy storage and compressed absorption refrigeration provided by the present invention, a preheating device is provided between the power generation module and the absorber module.

[0023] According to the combined cooling and power system of compressed air energy storage and compressed absorption refrigeration provided by the present invention, a first throttling valve is provided between the regenerator module and the absorber module.

[0024] According to the combined cooling and power system of compressed air energy storage and compression absorption refrigeration provided by the present invention, a second throttling valve is provided between the condensing device and the evaporating device.

[0025] The present invention provides a combined cooling and power system integrating compressed air energy storage and compression absorption refrigeration. By coupling the energy storage system and the cooling system, the compressed air cooling module compresses and cools the air before sending it into the air storage device. The air is then heated by the flow of the heat storage medium between the second heat storage device and the air heating module. The heated air is then used to generate electricity via the power generation module. The cooling system allows the residual heat of compression in the heat storage device after expansion power generation to be used to provide heat for absorption refrigeration, solving the problem of residual heat of compression and eliminating the need to wait for the high-temperature heat transfer medium in the heat storage device to cool naturally, thus shortening the system's operating cycle and improving system efficiency. The low-temperature air generated during the expansion power generation process is used to provide cooling to users, thus increasing the system's cooling capacity. This allows for effective utilization and improves the system's energy efficiency.

[0026] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of an embodiment of the combined cooling and power system that integrates compressed air energy storage and compression absorption refrigeration provided by the present invention.

[0029] Figure label:

[0030] 1. Gas storage device; 2. First heat storage device; 3. Second heat storage device; 4. Condensation device; 5. Evaporation device; 6. Electric motor; 7. First air compression device; 8. First air cooling device; 9. Second air compression device; 10. Second air cooling device; 11. Third air compression device; 12. Third air cooling device; 13. First air heating device; 14. Second air heating device; 15. Third air heating device; 16. First expander; 17. Second expander; 18. Third expander; 19. Power generation device; 20. First generator; 21. Second generator; 22. First regenerator; 23. Second regenerator; 24. First absorber; 25. Second absorber; 26. First booster pump; 27. Second booster pump; 28. Preheating device; 29. ​​First throttle valve; 30. Second throttle valve; 31. Auxiliary compressor. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0032] The following is combined with Figure 1 The present invention describes a combined cooling and power system that integrates compressed air energy storage and compression absorption refrigeration.

[0033] like Figure 1 The diagram shown is a schematic representation of an embodiment of a combined cooling and power (CCHP) system integrating compressed air energy storage and compression absorption refrigeration provided by the present invention. This embodiment of the CCHP system includes an energy storage system and a cooling system.

[0034] The energy storage system includes an air compression cooling module, an air storage device 1, a first thermal storage device 2, a second thermal storage device 3, an air heating module, and a power generation module. The first thermal storage device 2 is used to store a low-temperature thermal storage medium, and the second thermal storage device 3 is used to store a high-temperature thermal storage medium. During the compression energy storage process, the low-temperature thermal storage medium in the first thermal storage device 2 is passed into the air cooling device in the air compression cooling module to exchange heat with the air, thereby cooling the air. During the expansion energy release process, the high-temperature thermal storage medium in the second thermal storage device is passed into the air heating module to exchange heat with the air, thereby heating the air.

[0035] The cooling system includes a generator module, a regenerator module, an absorber module, a condenser 4, and an evaporator 5;

[0036] An air compression cooling module, an air storage device 1, an air heating module, and a power generation module are connected in sequence; a first heat storage device 2, an air compression cooling module, a second heat storage device 3, and an air heating module are connected in sequence; a second heat storage device 3, a generator module, a condenser device 4, an evaporator device 5, and an absorber module are connected in sequence; a second heat storage device 3, a generator module, a regenerator module, an absorber module, an air heating module, and a power generation module are connected in sequence.

[0037] Specifically, in this embodiment, the connection relationships of the various components / devices are as follows:

[0038] The air compression cooling module includes a motor 6 and three air compression cooling units connected in sequence. Each air compression unit includes an air compressor and an air cooler connected in sequence. The motor 6 drives the air compressor, which consists of a first air compressor 7, a first air cooler 8, a second air compressor 9, a second air cooler 10, a third air compressor 11, and a third air cooler 12. These three units are connected in sequence to form a stepped air compression cooling module. The third air cooler 12 is connected to an air storage device 1. After three stages of compression and cooling, the air reaches a set temperature and pressure, allowing it to be stored in the air storage device 1. The air heating module includes a first air heater 13, a second air heater 14, and a third air heater 15. The power generation module includes a first expander 16, a second expander 17, a third expander 18, and a power generation device 19 connected to the first expander 16, the second expander 17, and the third expander 18.

[0039] The generator module includes a first generator 20 (high-pressure generator) and a second generator 21 (low-pressure generator) connected in sequence; the regenerator module includes a first regenerator 22 and a second regenerator 23; the absorber module includes a first absorber 24 and a second absorber 25. The second absorber 25 is connected to the first regenerator 22 and the second regenerator 23 respectively, and a first booster pump 26 and a second booster pump 27 are respectively installed on the pipelines connecting the second absorber 25 to the first regenerator 22 and the second regenerator 23. The second absorber 25 is connected to the first air heating device 13, the second air heating device 14 and the third air heating device 15 respectively. A preheating device 28 is provided between the second absorber 25 and the first expander 16. The outlet ends of the first regenerator 22 and the second regenerator 23 are interconnected and then connected to the first absorber 24, and a first throttling valve 29 is provided on the pipeline connecting the outlet ends of the first regenerator 22 and the second regenerator 23 to the first absorber 24. The second heat storage device 3, the first generator 20, the second generator 21, the condensing device 4, the evaporating device 5, the second absorber 25 and the first absorber 24 are connected in sequence, and a second throttle valve 30 is provided between the condensing device 4 and the evaporating device 5, and an auxiliary compressor 31 is provided between the evaporating device 5 and the second absorber 25.

[0040] The following is a detailed description of the operation process of the combined compressed air energy storage and compression absorption refrigeration cogeneration system in this embodiment. Please refer to the appendix. Figure 1 .

[0041] During the compression and energy storage process, motor 6 drives the first air compressor 7, the second air compressor 9, and the third air compressor 11 to operate respectively. Normal temperature and pressure air enters the first air compressor 7 and is compressed into high-temperature, high-pressure compressed air. This high-temperature, high-pressure air is then cooled into low-temperature air after passing through the first air cooling device 8. The cooled low-temperature air then passes through the second air compressor 9, the second air cooling device 10, the third air compressor 11, and the third air cooling device 12 in sequence, repeating the above compression and cooling process. During this process, the heat storage medium in the first heat storage device 2 can enter the first air cooling device 8, the second air cooling device 10, and the third air cooling device 12 respectively to cool the compressed high-temperature, high-pressure air. The cooled high-pressure air is then passed into the air storage device 1 for storage, while the heat storage medium after heat exchange with the air is passed into the second heat storage device 3. It should be noted that the number of stages in the air compression and cooling unit can be adjusted according to actual conditions; it can be a single stage or multiple stages.

[0042] During the expansion and energy release process, the air in the gas storage device 1 is first introduced into the first air heating device 13. The heat storage medium in the second heat storage device 3 enters the first air heating device 13 to exchange heat with the air, raising the air temperature. After the temperature reaches the target, the high-temperature, high-pressure air is first introduced into the first expander 16 to expand and do work, driving the power generation device 19 to generate electricity. The heat storage medium, whose temperature has decreased after exchanging heat with the air, enters the first heat storage device 2. The air that has completed its expansion and work first passes through the preheating device 28 and exchanges heat with the cooling water therein, thereby lowering the temperature of the cooling water to achieve the desired effect. The air undergoes both cooling and preheating. After preheating, the air enters the first absorber 24 for further heat exchange to increase its temperature. The heated air then enters the second air heating device 14 for heating. After heating, the air enters the second expander 17 to expand and perform work, driving the generator 19 to generate electricity. The air, having completed its work in the second expander 17, returns to the first absorber 24 for heat exchange to further increase its temperature. The heated air then enters the third expander 18 to expand and perform work, again driving the generator 19 to generate electricity. During this process, the air pressure gradually decreases as it enters the first expander 16, second expander 17, and third expander 18, specifically from high pressure to medium pressure to low pressure. In each stage of the air heating device, the air exchanges heat with the heat storage medium in the second heat storage device 3, thus heating the air. The heat storage medium, after heat exchange, enters the first heat storage device 2 for storage, cooling the high-temperature air generated during the compression energy storage process.

[0043] In this embodiment, the combined cooling and power system integrating compressed air energy storage and compression absorption refrigeration generates two types of working fluid circulation during operation: a refrigerant working fluid circulation and a solution working fluid circulation.

[0044] In the refrigerant working fluid cycle, the first generator 20 and the second generator 21 are heated by the high-temperature heat storage medium that is not used in the second heat storage device 3, so that the refrigerant in the two generators evaporates into gas through heating. The gaseous refrigerant enters the condensing device 4 for condensation and heat release, and then becomes liquid again. The refrigerant passes through the second throttle valve 30 and enters the evaporating device 5 after cooling and depressurization. In the evaporating device 5, the refrigerant exchanges heat with the cooling water through the principle of evaporation and heat absorption to achieve the effect of cooling and evaporating the refrigerant into gas again. The gaseous refrigerant passes through the auxiliary compression device into the first absorber 24 and the second absorber 25, where the gaseous refrigerant is absorbed by the high-concentration absorbent at low temperature.

[0045] In the solution circulation, the solutions in the first generator 20 and the second generator 21, after being heated by the high-temperature heat storage medium in the second heat storage device 3, pass through the first regenerator 22 and the second regenerator 23 respectively to complete the heat exchange of the solution. The solutions cooled in the two regenerators will merge and pass through the first throttle valve 29 to cool down and then enter the first absorber 24 and the second absorber 25 in sequence to absorb the refrigerant. The mixed solution that has completed the absorption of refrigerant in the second absorber 25 will pass through the first booster pump 26 and the second booster pump 27 respectively to be heated in the first regenerator 22 and the second regenerator 23 and then stored again in the first generator 20 and the second generator 21.

[0046] In this way, the refrigerant cycle and solution cycle in the refrigeration system are completed.

[0047] As can be seen from the above description of the embodiments, the combined cooling and power system of the present invention, which combines compressed air energy storage and compression absorption refrigeration, has the following advantages:

[0048] This invention couples a compressed air energy storage system with an absorption refrigeration system. It utilizes the residual heat of compression in the second thermal storage device after expansion power generation to provide heat for the absorption refrigeration, enabling its normal operation. This system solves the problem of residual heat of compression, eliminating the need to wait for the high-temperature thermal storage medium in the second thermal storage device to cool naturally, thus saving significant time and shortening the system's operating cycle. Furthermore, the low-temperature air generated during expansion power generation is used to provide cooling to users, thus increasing the system's cooling capacity. This allows for effective utilization, thereby improving the system's energy efficiency and overall efficiency.

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A combined cooling and power system integrating compressed air energy storage and compression absorption refrigeration, characterized in that, Including energy storage systems and cooling systems: The energy storage system includes an air compression cooling module, an air storage device, a first thermal storage device, a second thermal storage device, an air heating module, and a power generation module. The cooling system includes a generator module, a regenerator module, an absorber module, a condenser device, and an evaporator device; The air compression cooling module, the air storage device, the air heating module, and the power generation module are connected in sequence; the first heat storage device, the air compression cooling module, the second heat storage device, and the air heating module are connected in sequence; the second heat storage device, the generator module, the condenser device, the evaporator device, and the absorber module are connected in sequence; the second heat storage device, the generator module, the regenerator module, the absorber module, the air heating module, and the power generation module are connected in sequence. The generator module includes at least one generator, and when multiple generators are included, all the generators are connected in sequence. The regenerator module includes regenerators that correspond one-to-one with the number of generators, and the regenerators are connected to the generators in a one-to-one correspondence. The absorber module includes at least one absorber, and when it includes multiple absorbers, all the absorbers are connected in sequence. The air compression cooling module includes at least one stage of air compression cooling unit, and each stage of the air compression cooling unit includes an air compression device and an air cooling device connected in sequence. When multiple stages of the air compression cooling unit are included, all the air compression cooling units are connected in sequence; the air storage device is connected to the air cooling device in the last stage of the air compression cooling unit; the first heat storage device is connected to the air cooling device in each stage of the air compression cooling unit, and the second heat storage device is connected to the air cooling device in each stage of the air compression cooling unit. A first throttling valve is provided between the regenerator module and the absorber module, and a second throttling valve is provided between the condenser device and the evaporator device.

2. The combined cooling and power system of compressed air energy storage and compression absorption refrigeration according to claim 1, characterized in that, The absorber module is connected to each of the regenerators; a booster pump is provided between the absorber module and each of the regenerators.

3. The combined cooling and power system of compressed air energy storage and compression absorption refrigeration according to claim 1, characterized in that, The air compression cooling module also includes an electric motor for driving the air compression device.

4. The combined cooling and power system of compressed air energy storage and compression absorption refrigeration according to claim 1, characterized in that, The air heating module includes at least one air heating device. When multiple air heating devices are included, the second heat storage device is connected to each air heating device, and the absorber module is connected to each air heating device.

5. The combined cooling and power system of compressed air energy storage and compression absorption refrigeration according to claim 4, characterized in that, The power generation module includes an expander and a power generation device. The expander is connected to the power generation device. The number of expanders and air heating devices are in one-to-one correspondence, and the expanders and air heating devices are connected in one-to-one correspondence.

6. The combined cooling and power system of compressed air energy storage and compression absorption refrigeration according to any one of claims 1-5, characterized in that, A preheating device is provided between the power generation module and the absorber module.

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