Liquid air energy storage power generation system and method

Abstract

The application discloses a liquid air energy storage power generation system and method. The system comprises: a compression filtering heat storage unit for converting air into clean compressed air and recovering compression heat energy; an energy storage unit for liquefying clean compressed air through multi-stage cooling and storing liquid air; and a power generation unit for multi-stage heating of pressurized liquid air to obtain gaseous pressurized air while recovering cold energy, and heating the gaseous pressurized air by using the compression heat energy to generate power. The application stores surplus electric energy as liquid air and recovers compression heat energy in the energy storage stage, pressurizes the liquid air in the energy release stage, and then performs multi-stage heating and recovers cold energy. The compression heat energy recovered in the energy storage stage is used for heating again, and then power generation is performed, realizing energy conversion from electric energy to compression heat, improving electric energy utilization rate and system stability, making up for the intermittency and randomness of renewable energy power generation, and improving the utilization rate of cold energy.

Description

Technical Field

[0001] This invention belongs to the field of electrical energy storage, and more specifically, relates to a liquid air energy storage power generation system and method. Background Technology

[0002] With population growth and industrialization, the conflict between power supply capacity and electricity demand has become increasingly apparent. This is particularly true in China, where thermal power is the primary source of electricity, and the greenhouse gas emissions and environmental pollution caused by fossil fuel power generation are drawing growing public attention. While renewable energy generation can significantly reduce greenhouse gas emissions and environmental pollution, its uneven distribution, randomness, and intermittency can lead to unstable power generation and insufficient supply during peak demand periods. When the power grid fails, localized areas may experience power crises, causing problems related to safety, production, and people's livelihoods. A stable and reliable energy storage system can effectively compensate for the shortcomings of renewable energy, and the development of such systems has significant engineering implications.

[0003] Liquid air storage (LISS) is a technology for improving grid stability. During off-peak hours, surplus electricity is used to compress liquid air, storing the energy in liquid air form. During peak hours, the liquid air is vaporized, expanding to generate electricity and releasing the energy within, thus filling peak demand and mitigating the instability of renewable energy generation. Furthermore, liquid air is an environmentally friendly storage medium with no geographical limitations and high energy density. In summary, this energy storage and power generation method compensates for the randomness and intermittency of renewable energy generation, stabilizing fluctuations and smoothing out peak and valley loads. However, LISS technology is still in its early stages and is not yet mature; further exploration and improvement are needed. This invention provides a feasible, highly efficient, stable, and controllable LISS system with broad engineering prospects.

[0004] The information disclosed in the background section of this invention is intended only to enhance the understanding of the general background of this invention, and should not be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to propose a liquid air energy storage and power generation system and method, which realizes the storage of surplus electrical energy as liquid air, while recovering the compression heat energy generated during the compression process. In the energy release stage, the pressurized liquid air is cold-recovered, and the compression heat energy recovered in the energy storage stage is used to heat the cold-recovered gaseous pressurized air, thereby enabling the turbine unit to work and generate electricity, realizing the energy conversion from electrical energy to compression heat, and then back to electrical energy.

[0006] To achieve the above objectives, the present invention proposes a liquid air energy storage power generation system and method.

[0007] According to a first aspect of the present invention, a liquid air energy storage and power generation system is provided, comprising:

[0008] A compression-filtration heat storage unit is used to compress air to obtain compressed air, and exchange the compressed air with a heat storage medium to obtain the heat storage medium that absorbs heat; the compressed air that has completed the heat exchange is cooled and filtered to obtain clean compressed air, and the clean compressed air is compressed again to exchange heat with the heat storage medium again; the heat storage medium that absorbs heat stores the compressed heat energy in the compressed air or the clean compressed air; the clean compressed air that has completed the last heat exchange is cooled and then delivered to the energy storage unit.

[0009] An energy storage unit is used to liquefy the cooled clean compressed air through multi-stage cooling to obtain liquid air and store it.

[0010] The power generation unit is used to, during the energy release phase, pressurize the liquid air stored in the energy storage unit and input the liquid air into the power generation unit. The pressurized liquid air is then heated in multiple stages using a cooling medium recovered during the cooling process of the compression-filtration heat storage unit and the energy storage unit to obtain gaseous pressurized air. The gaseous pressurized air is then heated using the compressed heat energy stored in the heat storage medium, and the heated gaseous pressurized air is used to generate electricity. Cold energy is recovered during the multi-stage heating process using the cooling medium.

[0011] Optionally, the compression filtration heat storage unit includes:

[0012] Multiple compression heat exchange modules are connected in sequence. Each compression heat exchange module is used to compress the air or the compressed air output by the previous compression heat exchange module, and to exchange the compressed air generated by each compression heat exchange module with the heat storage medium.

[0013] A cooling and filtering module is disposed among the plurality of compression heat exchange modules. The cooling and filtering module is used to store a first cooling medium and to exchange heat between the compressed air output from the compression heat exchange module connected to the front stage of the cooling and filtering module and the first cooling medium to obtain the released first cooling medium, which is then stored. The compressed air that has completed the heat exchange is then filtered. The filtered compressed air is then delivered to the compression heat exchange module connected to the rear stage of the cooling and filtering module for further compression and heat exchange.

[0014] A final stage water-cooled module for compression, wherein the input end of the final stage water-cooled module is connected to the output end of the last compression heat exchange module, and is used to cool the clean compressed air output by the last compression heat exchange module by means of cooling water;

[0015] A heat storage medium module is used to store the heat storage medium and the heat-absorbing heat storage medium, and to store the compressed heat energy by storing the heat-absorbing heat storage medium.

[0016] Optionally, the energy storage unit includes:

[0017] The pre-cooling module is used to exchange heat between the clean compressed air output from the compression filtration heat storage unit and the second cooling medium and the third cooling medium output from the liquefaction cooling module, and to store the released second cooling medium; and to expand and cool a portion of the clean compressed air that has completed the heat exchange to obtain expanded air.

[0018] The liquefaction cooling module is used to exchange heat between the clean compressed air that has completed the heat exchange and the fourth cooling medium and the third cooling medium to obtain the liquid air, and to store the released fourth cooling medium; and to perform expansion and decompression cooling on the liquid air output by the liquefaction module.

[0019] A liquid air storage module is used to store the liquid air that has completed the expansion, decompression and cooling process; the expanded air and the evaporated gas generated by the liquid air that has completed the expansion, decompression and cooling process are combined to form the third cooling medium and are sequentially transported to the liquefaction cooling module and the pre-cooling refrigeration module to exchange heat with another part of the clean compressed air that has completed the heat exchange and the clean compressed air output from the compression filter heat storage unit.

[0020] The input terminal of the liquefaction cooling module is connected to the output terminal of the pre-cooling refrigeration module, the input terminal of the liquid air storage module is connected to the output terminal of the liquefaction cooling module, the low-temperature depressurized air input terminal of the liquid air storage module is connected to the low-temperature depressurized air output terminal of the pre-cooling refrigeration module, the third cooling medium output terminal of the liquid air storage module is connected to the third cooling medium input terminal of the liquefaction cooling module, and the third cooling medium output terminal of the liquefaction cooling module is connected to the third cooling medium input terminal of the pre-cooling refrigeration module.

[0021] Optionally, the power generation unit includes:

[0022] A pressurization module is used to pressurize the liquid air stored in the liquid air storage module and then deliver it to the first cold energy recovery module;

[0023] The first cold energy recovery module is used to exchange heat between the released fourth cooling medium and the pressurized liquid air, heat the liquid air to obtain gaseous pressurized air, and recover the cold energy in the liquid air through the released fourth cooling medium.

[0024] The second cold energy recovery module is used to exchange heat between the released second cooling medium and the gaseous pressurized air to heat the gaseous pressurized air, and to recover the cold energy in the gaseous pressurized air through the released second cooling medium.

[0025] The third cold energy recovery module is used to exchange heat again between the first cooling medium that has released cold and the gaseous pressurized air that has completed the heat exchange, to reheat the gaseous pressurized air, and to recover the cold energy in the gaseous pressurized air again through the first cooling medium that has released cold.

[0026] A plurality of expansion power generation modules, each of the expansion power generation modules including one air expansion preheating module and one power generation module, wherein the output end of the air expansion preheating module is connected to the input end of the power generation module, and all the expansion power generation modules are connected in sequence;

[0027] The air expansion preheating module is used to exchange heat between the heat storage medium that absorbs heat and the pressurized gaseous air that has completed the multi-stage heating.

[0028] The power generation module is used to generate electricity from the gaseous pressurized air that has undergone heat exchange in the air expansion and preheating module.

[0029] The input terminal of the pressurization module is connected to the output terminal of the liquid air storage module, the output terminal of the pressurization module is connected to the input terminal of the first cold energy recovery module, the output terminal of the first cold energy recovery module is connected to the input terminal of the second cold energy recovery module, the output terminal of the second cold energy recovery module is connected to the input terminal of the third cold energy recovery module, and the output terminal of the third cold energy recovery module is connected to the input terminal of the first air expansion preheating module.

[0030] Optionally, the compression heat exchange module includes:

[0031] A compression module is used to compress the air or to recompress the filtered clean compressed air;

[0032] A compression heat recovery module is used to exchange heat between the heat storage medium and the compressed air or the clean compressed air output by the compression module, and to recover the compressed heat energy through the heat storage medium.

[0033] The output end of the compression module is connected to the input end of the compression heat recovery module.

[0034] Optionally, the cooling filter module includes:

[0035] A pre-filter cooling module is used to exchange heat between the compressed air output from the compression heat exchange module connected to the pre-filter cooling module and the first cooling medium; the input end of the pre-filter cooling module is connected to the output end of the compression heat exchange module connected to the pre-filter.

[0036] A filtration module is used to filter the compressed air output from the pre-filtration cooling module to obtain clean compressed air, and to deliver the clean compressed air to the compression heat exchange module connected to the downstream stage of the filtration module for compression; the input end of the filtration module is connected to the output end of the pre-filtration cooling module, and the output end of the filtration module is connected to the input end of the compression heat exchange module connected to the downstream stage.

[0037] A first cooling medium storage module is used to store the first cooling medium;

[0038] A first cooling medium storage module for storing the released first cooling medium;

[0039] The cooling medium input terminal of the pre-filtration cooling module is connected to the output terminal of the cold first cooling medium storage module, the cooling medium output terminal of the pre-filtration cooling module is connected to the input terminal of the hot first cooling medium storage module, the cooling medium output terminal of the third cold energy recovery module is connected to the input terminal of the cold first cooling medium storage module, and the cooling medium input terminal of the third cold energy recovery module is connected to the output terminal of the hot first cooling medium storage module.

[0040] Optionally, the heat storage medium module includes:

[0041] A cold heat storage medium storage module is used to store the heat storage medium;

[0042] A thermal storage medium module for storing the heat-absorbing storage medium;

[0043] The input terminal of the heat storage medium of the compression heat recovery module is connected to the output terminal of the cold heat storage medium storage module, the output terminal of the heat storage medium of the compression heat recovery module is connected to the input terminal of the hot heat storage medium storage module, the input terminal of the cold heat storage medium storage module is connected to the output terminal of the heat storage medium of the air expansion preheating module, and the output terminal of the hot heat storage medium storage module is connected to the input terminal of the heat storage medium of the air expansion preheating module. Optionally, the pre-cooling module includes:

[0044] The pre-cooling module includes:

[0045] An air precooling module is used to exchange heat between the second cooling medium, the third cooling medium output from the liquefaction cooling module, and the clean compressed air output from the final stage water cooling module.

[0046] A second cooling medium storage module is used to store the second cooling medium;

[0047] A second cooling medium storage module for storing the released second cooling medium;

[0048] An air cooling expansion module is used to expand and cool a portion of the clean compressed air output from the air precooling module to obtain expanded air.

[0049] The input terminal of the air precooling module is connected to the output terminal of the final stage water-cooling module of the compressor. The second cooling medium input terminal of the air precooler is connected to the output terminal of the cold second cooling medium storage module. The second cooling medium output terminal of the air precooling module is connected to the input terminal of the hot second cooling medium storage module. The input terminal of the cold second cooling medium storage module is connected to the cooling medium output terminal of the second cold energy recovery module. The output terminal of the hot second cooling medium storage module is connected to the cooling medium input terminal of the second cold energy recovery module. The input terminal of the air refrigeration expansion module is connected to the second output terminal of the air precooling module. The output terminal of the air refrigeration expansion module is connected to the low-temperature depressurized air input terminal of the liquid air storage module.

[0050] Optionally, the liquefaction module shown includes...

[0051] An air liquefaction module is used to exchange heat between the fourth cooling medium, the third cooling medium output from the liquid air storage module, and the clean compressed air output from the first output terminal of the air precooling module to obtain the liquid air;

[0052] A fourth cooling medium storage module is used to store the fourth cooling medium;

[0053] A fourth cooling medium storage module for storing the released fourth cooling medium;

[0054] A liquid air expansion module is used to expand, depressurize, and cool the liquid air output from the air liquefaction module;

[0055] The input terminal of the air liquefaction module is connected to the first output terminal of the air precooling module; the cooling medium input terminal of the air liquefaction module is connected to the output terminal of the cold fourth cooling medium storage module; the cooling medium output terminal of the air liquefaction module is connected to the input terminal of the hot fourth cooling medium storage module; the input terminal of the cold fourth cooling medium storage module is connected to the cooling medium output terminal of the first cold energy recovery module; and the output terminal of the hot fourth cooling medium storage module is connected to the cooling medium input terminal of the first cold energy recovery unit. The input terminal of the liquid air expansion module is connected to the output terminal of the air liquefaction module, and the output terminal of the liquid air expansion module is connected to the liquid air storage module.

[0056] According to a second aspect of the present invention, a liquid air energy storage and power generation method is provided, applied to the liquid air energy storage system described in any one of the first aspects, comprising:

[0057] In the energy storage stage, compressed air is obtained by compressing air, and the compressed air is then exchanged with a heat storage medium to obtain a heat-absorbing heat storage medium. The compressed air that has completed the heat exchange is cooled and filtered to obtain clean compressed air, which is then compressed again and exchanged with the heat storage medium again. The heat energy of the compressed air or the clean compressed air is stored in the heat-absorbing heat storage medium. The clean compressed air that has completed the last heat exchange is cooled and then delivered to the energy storage unit.

[0058] The clean compressed air that has undergone cooling is liquefied through multi-stage cooling to obtain liquid air, which is then stored.

[0059] During the energy release phase, the liquid air stored in the energy storage unit is pressurized and input into the power generation unit. The pressurized liquid air is then heated in multiple stages using the cooling medium recovered during the cooling process of the compression filtration heat storage unit and the energy storage unit to obtain gaseous pressurized air. The gaseous pressurized air is then heated by the compressed heat energy stored in the heat storage medium, and power is generated from the heated gaseous pressurized air. Cold energy is recovered during the multi-stage heating process using the cooling medium.

[0060] The beneficial effects of this invention are as follows: In the energy storage stage, surplus electrical energy is stored as liquid air, while simultaneously recovering the heat energy generated during compression. In the energy release stage, the pressurized liquid air undergoes cold recovery, recovering cold energy and regenerating a low-temperature cooling medium. The heat energy recovered in the energy storage stage is used to heat the gaseous pressurized air that has undergone cold recovery, resulting in high-temperature gaseous pressurized air. This allows the power generation module to generate electricity using the high-temperature gaseous pressurized air, thus achieving energy conversion from electrical energy to heat energy and back to electrical energy. Furthermore, the energy storage and energy release stages of this invention can operate independently; the energy release stage can be performed without starting the compressor unit. In certain situations, the system independently generates electricity using a heat source (compressed heat energy), providing greater flexibility for the entire system. By connecting the energy storage power generation system of this invention in parallel with the power grid, it compensates for the intermittency and randomness of renewable energy power generation, allowing for smooth fluctuations, peak shaving, and valley filling. It provides the ability to intervene when the power grid fluctuates, enabling the grid to generate electricity stably, thus improving energy utilization and system stability. At the same time, liquid air is an environmentally friendly energy storage medium that is not limited by geographical conditions and has a high energy storage density. Compared with traditional battery energy storage technology, this invention has a higher storage density, higher energy storage efficiency, and does not pollute the environment.

[0061] The system of the present invention has other features and advantages that will be apparent from or will be set forth in detail in the accompanying drawings and following detailed description, which together serve to explain the particular principles of the invention. Attached Figure Description

[0062] The above and other objects, features and advantages of the present invention will become more apparent from the accompanying drawings, in which like reference numerals generally denote like parts.

[0063] Figure 1 A schematic diagram of a liquid air energy storage and power generation system according to the present invention is shown.

[0064] Figure 2 A schematic diagram of a liquid air energy storage and power generation system according to Embodiment 1 of the present invention is shown.

[0065] Figure 3 A schematic diagram of a liquid air energy storage and power generation system (including a liquid air separator) according to Embodiment 1 of the present invention is shown.

[0066] Figure 4 A flowchart illustrating the steps of a liquid air energy storage and power generation method according to Embodiment 2 of the present invention is shown.

[0067] Explanation of reference numerals in the attached figures:

[0068] 1. Compressor; 2. Compression heat recovery unit; 3. Compression terminal water cooler; 4. Molecular sieve precooler; 5. Molecular sieve; 6. Hot molecular sieve cooling medium storage tank; 7. Cold molecular sieve cooling medium storage tank; 8. Molecular sieve postheat exchanger; 9. Air precooler; 10. Air refrigeration expander; 11. Air liquefaction unit; 12. Liquid air expansion valve; 13. Liquid air separator; 14. Liquid air storage tank; 15. Hot shallow cold medium storage tank; 16. Cold shallow cold medium storage tank; 17. Hot deep cold medium storage tank; 18. Cold deep cold medium storage tank; 19. Hot heat storage medium storage module; 20. Cold heat storage medium storage module; 21. Deep cold recovery unit; 22. Shallow cold recovery unit; 23. Air expansion preheater; 24. Turbine generator set; 25. Booster pump. Detailed Implementation

[0069] The invention will now be described in more detail with reference to the accompanying drawings. While preferred embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0070] like Figure 1 As shown, a liquid air energy storage and power generation system according to the present invention includes...

[0071] The compression filtration heat storage unit is used to compress air to obtain compressed air, and then exchange heat between the compressed air and the heat storage medium to obtain a heat-absorbing heat storage medium; the compressed air that has completed the heat exchange is cooled and filtered to obtain clean compressed air, and the clean compressed air is compressed again and then exchanged heat with the heat storage medium again; the heat energy of the compressed air or clean compressed air is stored through the heat-absorbing heat storage medium; the clean compressed air that has completed the last heat exchange is cooled and then delivered to the energy storage unit.

[0072] The energy storage unit is used to liquefy cooled clean compressed air through multi-stage cooling to obtain liquid air for storage.

[0073] The power generation unit is used to pressurize the liquid air stored in the energy storage unit during the energy release phase, so that the liquid air is input into the power generation unit. The pressurized liquid air is then heated in multiple stages by the cooling medium recovered during the cooling process of the compression filtration heat storage unit and the energy storage unit to obtain gaseous pressurized air. The gaseous pressurized air is then heated by the compressed heat energy stored in the heat storage medium, and then the heated gaseous pressurized air is used to generate electricity. Cold energy is recovered by the cooling medium during the multi-stage heating process.

[0074] Specifically, the liquid air energy storage and power generation system of the present invention includes a compression filtration heat storage unit, an energy storage unit, and a power generation unit. During off-peak electricity demand, the compression filtration heat storage unit stores electrical energy as liquid air, which is the energy storage stage. The compression filtration heat storage unit first compresses the outside air using electrical energy to obtain high-temperature and high-pressure compressed air. After the pressure of the compressed air meets the inlet pressure requirements of the filtration equipment, the compressed air is filtered. The filtration removes excess water vapor and oil droplets, as well as solid impurities such as rust, sand, and pipe sealant from the compressed air coming from the air source. After filtration, compression continues until the pressure of the clean compressed air meets the process requirements. During the compression process, the heat energy generated by compression is stored through a heat storage medium and used to heat the compressed air during the energy release stage to make it expand and increase its temperature, thus saving energy by utilizing the heat energy of compression. The clean compressed air is then liquefied through multi-stage cooling by the energy storage unit to obtain liquid air. The temperature is very low, requiring cooling from approximately 60°C to -190°C. It's difficult to find a single cooling medium that can remain liquid throughout this temperature range. Therefore, multiple cooling media are used for multi-stage cooling, such as a two-stage cooling system. The first stage uses a liquid first cooling medium and lower-temperature flash air to pre-cool the clean compressed air output from the compressed air filter and heat storage unit. A portion of the pre-cooled clean compressed air is then separated, expanded, and cooled to supplement the third cooling medium (flash air), thus replenishing the cooling capacity for the clean compressed air. The second stage uses a liquid second cooling medium (lower than the first cooling medium) and the third cooling medium to further reduce the temperature of the compressed air, causing it to liquefy. After heat exchange in the second stage, the temperature of the third cooling medium is close to that of the first cooling medium, so it is input into the first stage to cool the compressed air together with the first cooling medium, fully utilizing the cold energy. Through multi-stage cooling, the clean compressed air can be liquefied more efficiently, improving the liquefaction rate of the compressed air and the utilization rate of cold energy.After liquefaction, the liquid air is stored in an energy storage unit for power generation during peak demand periods, filling the gap in electricity supply and ensuring stable grid power generation, thus improving energy utilization and system stability. In the energy release phase, the liquid air stored in the energy storage unit is pressurized by the power generation unit, increasing its pressure. Then, through multi-stage heating, the high-pressure liquid air is vaporized to obtain pressurized gaseous air. The cooling medium used in the multi-stage heating process includes the cooling medium released during the multi-stage cooling process in the energy storage unit and the cooling medium released after cooling the compressed air before filtration in the compression filtration heat storage unit. By recovering valuable cold energy and regenerating the cooling medium through the multi-stage heating process, the system achieves... The system achieves the recycling of cooling medium and cold energy; the compressed heat energy stored in the compression and filtration heat storage unit heats the gaseous pressurized air, further increasing its temperature to obtain high-temperature, high-pressure air, which in turn raises the temperature at the expander inlet, thereby improving expansion efficiency. Simultaneously, the released heat storage medium is recovered, achieving its recycling. Finally, the high-temperature, high-pressure air is used to generate electricity, which is used to fill peak electricity demand, improving energy utilization and system stability. In this system, a control module can also be set up to control the operation of each device during the energy storage and release phases, such as starting / stopping devices, controlling valves, and adjusting flow rate, pressure, and temperature.

[0075] In one example, the compressed filter thermal storage unit includes:

[0076] Multiple compression heat exchange modules are connected in sequence. Each compression heat exchange module is used to compress air or compressed air output from the previous compression heat exchange module, and to exchange heat between the compressed air generated by each compression heat exchange module and the heat storage medium.

[0077] A cooling and filtering module is located between multiple compression heat exchange modules. The cooling and filtering module stores the first cooling medium and exchanges heat with the compressed air output from the compression heat exchange module connected to the front of the cooling and filtering module to obtain the first cooling medium that has been released and stored. The compressed air that has completed the heat exchange is then filtered. The filtered compressed air is then delivered to the compression heat exchange module connected to the rear of the cooling and filtering module for compression heat exchange again.

[0078] The final stage water-cooled module is connected to the output of the last compression heat exchange module. It is used to cool the clean compressed air output by the last compression heat exchange module with cooling water.

[0079] The heat storage medium module is used to store heat storage medium and heat-absorbing heat storage medium, and to store compressed heat energy by storing heat-absorbing heat storage medium.

[0080] Specifically, the compression filtration heat storage unit includes multiple compression heat exchange modules, a cooling filtration module, a final-stage water-cooling module, and a heat storage medium module. Multiple compression heat exchange modules are connected sequentially, with the cooling filtration module placed between two compression heat exchange modules. The installation location of the cooling filtration module is selected based on the required inlet compressed air pressure of the filtration equipment. The number of compression heat exchange modules is selected based on process requirements and the performance of the compression heat exchange modules. Air is compressed stage by stage through multiple compression heat exchange modules until the compressed air pressure meets the process requirements. Then, the clean compressed air output from the last compression heat exchange module is cooled by the final-stage water-cooling module. Each compression module exchanges heat with the high-temperature compressed air it compresses through the heat storage medium to reduce the temperature of the compressed air. Simultaneously, the heat storage medium recovers the compression heat energy. The clean compressed air output from the last compression heat exchange module is cooled by the final stage water-cooling module, further reducing its temperature so that it can be more easily liquefied in the energy storage unit. Simultaneously, the heat energy generated during compression is recovered for use in the energy release phase. During compression, the compressed air output from the previous compression heat exchange module is cooled by the first cooling medium of the cooling filter module. The cooled compressed air is then filtered by a filtration device to remove excessive water vapor, oil droplets, and solid impurities, preventing contamination and damage to the power generation equipment. For example, molecular sieve equipment can be used for filtration. The resulting clean compressed air is then compressed further. The heated heat storage medium is stored in the heat storage module to store the heat energy generated during compression and use it in the energy release phase, thus reusing the compressed heat energy.

[0081] In one example, the energy storage unit includes:

[0082] The pre-cooling module is used to exchange heat between the clean compressed air output from the compression filtration heat storage unit and the second cooling medium and the third cooling medium output from the liquefaction cooling module, and to store the released second cooling medium; it also expands and cools a portion of the clean compressed air that has completed the heat exchange to obtain expanded air.

[0083] The liquefaction cooling module is used to exchange heat between another portion of the clean compressed air that has completed heat exchange and the fourth and third cooling media to obtain liquid air, and to store the released fourth cooling media; and to perform expansion, decompression and cooling on the liquid air output by the liquefaction module.

[0084] The liquid air storage module is used to store the liquid air that has completed expansion, decompression and cooling. The expanded air and the evaporated gas generated by the liquid air that has completed expansion, decompression and cooling are combined to form a third cooling medium, which is then sequentially transported to the liquefaction cooling module and the pre-cooling refrigeration module to exchange heat with another part of the clean compressed air that has completed heat exchange and the clean compressed air output from the compression filter heat storage unit.

[0085] The input terminal of the liquefaction cooling module is connected to the output terminal of the pre-cooling refrigeration module; the input terminal of the liquid air storage module is connected to the output terminal of the liquefaction cooling module; the low-temperature depressurized air input terminal of the liquid air storage module is connected to the low-temperature depressurized air output terminal of the pre-cooling refrigeration module; the third cooling medium output terminal of the liquid air storage module is connected to the third cooling medium input terminal of the liquefaction cooling module; and the third cooling medium output terminal of the liquefaction cooling module is connected to the third cooling medium input terminal of the pre-cooling refrigeration module.

[0086] Specifically, the energy storage unit includes a pre-cooling module, a liquefaction cooling module, and a liquid air storage module. Liquid air is obtained through two-stage cooling via the pre-cooling and liquefaction cooling modules and stored in the liquid air storage module. Specifically, the pre-cooling module exchanges heat between the clean compressed air output from the compressed air filtration and heat storage unit and the second and third cooling media output from the liquefaction cooling module to further cool the compressed air, thus completing the pre-cooling process. A portion of the pre-cooled clean compressed air undergoes expansion cooling, reducing its temperature and pressure to obtain low-temperature expanded air. This expanded air is then transported to the liquid air storage module to replenish the third cooling media used in the cooling process. The liquefaction cooling module exchanges heat between another portion of the pre-cooled clean compressed air and the low-temperature fourth and third cooling media, causing the clean compressed air to liquefy, depressurize, and expand before being transported to the liquid air storage module for storage. The lower the pressure of the liquid air... The higher the storage safety, the better. However, if the liquid air storage module cannot withstand high pressure, for example, if the liquid air storage module is an atmospheric pressure tank, then a liquid air separator should be added at the inlet of the atmospheric pressure tank. The low-temperature depressurized air generated by the pre-cooling refrigeration module and the liquid air generated by the liquefaction cooling module first enter the liquid air separator. The flash air formed by the low-temperature depressurized air and the liquid air is combined into the third cooling medium, which is transported from the air output end of the liquid air separator to the liquefaction cooling module. After heat exchange, it is then transported to the pre-cooling refrigeration module. The liquid air is transported from the liquid output end of the liquid air separator to the atmospheric pressure tank for storage. The third cooling medium completes heat exchange in the liquid air storage module and then enters the pre-cooling refrigeration module for heat exchange, thereby further recovering and utilizing the cold energy of the flash air and further improving the system's energy utilization efficiency. The third cooling medium that has completed heat exchange is transported to the inlet of the first compression heat exchange module for compression. Since the third cooling medium has been filtered, the consumption of filter material can be effectively reduced.

[0087] In one example, the power generation unit includes:

[0088] The pressurization module is used to pressurize the liquid air stored in the liquid air storage module and then deliver it to the first cold energy recovery module;

[0089] The first cold energy recovery module is used to exchange heat between the released fourth cooling medium and the pressurized liquid air, heat the liquid air to obtain gaseous pressurized air, and recover the cold energy in the liquid air through the released fourth cooling medium.

[0090] The second cold energy recovery module is used to exchange heat between the released second cooling medium and the gaseous pressurized air to heat the gaseous pressurized air, and to recover the cold energy in the gaseous pressurized air through the released second cooling medium.

[0091] The third cold energy recovery module is used to exchange heat again between the first cooling medium that has released cold and the gaseous pressurized air that has completed heat exchange, to reheat the gaseous pressurized air, and to recover the cold energy in the gaseous pressurized air again through the first cooling medium that has released cold.

[0092] Several expansion power generation modules, each expansion power generation module includes one air expansion preheating module and one power generation module, the output end of the air expansion preheating module is connected to the input end of the power generation module, and all expansion power generation modules are connected in sequence;

[0093] The air expansion preheating module is used to exchange heat between the heat-absorbing heat storage medium and the pressurized gaseous air that has completed multi-stage heating.

[0094] The power generation module is used to generate electricity by using pressurized gaseous air that has undergone heat exchange in the air expansion preheating module;

[0095] The input terminal of the pressurization module is connected to the output terminal of the liquid air storage module, the output terminal of the pressurization module is connected to the input terminal of the first cold energy recovery module, the output terminal of the first cold energy recovery module is connected to the input terminal of the second cold energy recovery module, the output terminal of the second cold energy recovery module is connected to the input terminal of the third cold energy recovery module, and the output terminal of the third cold energy recovery module is connected to the input terminal of the first air expansion preheating module.

[0096] Specifically, the power generation unit includes a pressurization module, a first cold energy recovery module, a second cold energy recovery module, a third cold energy recovery module, and several expansion power generation modules. During the energy release phase, the pressurization module pressurizes the liquid air stored in the liquid air storage module and sequentially inputs it into the first, second, and third cold energy recovery modules for three-stage heating, resulting in heated gaseous pressurized air. Simultaneously, it recovers the cold energy from the liquid air and regenerates the first, second, and fourth cooling media for use in the energy storage phase, enabling the first, second, and fourth cooling media and cold energy to be recycled. During the energy release phase, the pressurization module pressurizes the liquid air stored in the liquid air storage module and delivers it to the first, second, and third cold energy recovery modules for further heating. A cold energy recovery module is used. First, the liquid air is exchanged with a fourth cooling medium that has been cooled and heated after release, vaporizing the liquid pressurized air to obtain gaseous pressurized air and recovering the cold energy from it. Second, the gaseous pressurized air is exchanged with a second cooling medium that has been cooled and heated after release, recovering the cold energy from the gaseous pressurized air and simultaneously increasing its temperature. Third, the first cooling medium that has been cooled and heated after release is exchanged with the heated gaseous pressurized air output from the second cold energy recovery module, further recovering residual cold energy from the gaseous pressurized air. This provides the necessary cold energy to the cooling and filtration module and continues to increase the temperature of the gaseous pressurized air. The first expansion power generation module's air expansion preheating module exchanges heat with the heat storage medium (which has absorbed heat and then heated up) stored in the thermal storage medium storage module. This utilizes the compressed heat stored during the energy storage phase to heat the gaseous pressurized air, resulting in high-temperature, high-pressure gaseous air. This high-temperature, high-pressure gaseous air is then fed into the power generation module of the first expansion power generation module for power generation. The cooled and depressurized gaseous air, after power generation, then enters the second expansion power generation module's air expansion preheating module and exchanges heat with the heat storage medium (which has absorbed heat and then heated up) stored in the thermal storage medium storage module again, resulting in high-temperature, high-pressure gaseous air. This high-temperature, high-pressure gaseous air is then fed into the power generation module of the second expansion power generation module for power generation. This process continues until the last expansion power generation module completes its power generation. The air passing through the last expansion power generation module may still contain some heat energy that can be recovered and utilized. At this point, an air expansion preheating module can be added before the air expansion preheating module of the first expansion power generation module. Through this air expansion preheating module, the air containing some heat energy discharged from the last expansion power generation module is first exchanged with the gaseous pressurized air output from the third cold energy recovery module to increase its temperature and reduce the consumption of compression heat energy. This further recovers the remaining heat of the air discharged from the last expansion power generation module, thereby improving the overall energy utilization efficiency of the system. After the waste heat is recovered, the air discharged from the last expansion power generation module can be directly discharged into the atmosphere.

[0097] In one example, the compression heat exchange module includes:

[0098] A compression module is used to compress air or to recompress filtered clean compressed air;

[0099] The compression heat recovery module is used to exchange heat between the heat storage medium and the compressed air or clean compressed air output by the compression module, and to recover the compressed heat energy through the heat storage medium.

[0100] The output of the compression module is connected to the input of the compression heat recovery module.

[0101] Specifically, each compression heat exchange module includes a compression module and a compression heat recovery module. The output end of the compression module is connected to the input end of the compression heat recovery module. The first compression module compresses low-pressure air to obtain high-temperature, high-pressure compressed air, which is then sent to the first compression heat recovery module to exchange heat with the heat storage medium, reducing the temperature of the compressed air and recovering the heat of compression. It is then sent to the second compression module for further compression, and then to the second compression heat recovery module for heat exchange with the heat storage medium. After the heat exchange is completed, it is sent to the third compression module for further compression, and so on. The cooling filter module is installed in a suitable position according to the inlet pressure requirements of the filtration equipment, so that the pressure of the compressed air output from the previous compression heat exchange module meets the inlet pressure requirements of the filtration equipment. After compression by all compression modules, the compressed air is sent to the end-compression water-cooling module for cooling, reducing the temperature of the clean compressed air so as to achieve more efficient liquefaction. The number of compression heat exchange modules is selected according to the process requirements.

[0102] In one example, the cooling filter module includes:

[0103] The pre-filter cooling module is used to exchange heat between the compressed air output from the compression heat exchange module connected to the front stage of the pre-filter cooling module and the first cooling medium; the input end of the pre-filter cooling module is connected to the output end of the compression heat exchange module connected to the front stage.

[0104] The filter module is used to filter the compressed air output from the pre-filter cooling module to obtain clean compressed air, and then deliver the clean compressed air to the compression heat exchange module connected to the downstream stage of the filter module for compression. The input end of the filter module is connected to the output end of the pre-filter cooling module, and the output end of the filter module is connected to the input end of the downstream compression heat exchange module.

[0105] A cold first cooling medium storage module is used to store the first cooling medium;

[0106] A first cooling medium storage module for storing the released first cooling medium;

[0107] The cooling medium input terminal of the pre-filtration cooling module is connected to the output terminal of the cold first cooling medium storage module, the cooling medium output terminal of the pre-filtration cooling module is connected to the input terminal of the hot first cooling medium storage module, the cooling medium output terminal of the third cold energy recovery module is connected to the input terminal of the cold first cooling medium storage module, and the cooling medium input terminal of the third cold energy recovery module is connected to the output terminal of the hot first cooling medium storage module.

[0108] Specifically, the cooling and filtration module includes a pre-filtration cooling module, a filtration module, a cold first cooling medium storage module, and a hot first cooling medium storage module. The input end of the pre-filtration cooling module is connected to the output end of its preceding compression heat exchange module, specifically to the output end of its compression heat recovery module. The input end of the filtration module is connected to the output end of the pre-filtration cooling module, and the output end of the filtration module is connected to the input end of its subsequent compression heat exchange module. This means that the compressed air output from the preceding compression heat recovery module undergoes heat exchange in the pre-filtration cooling module before entering the filtration module for filtration. The clean compressed air obtained after filtration then enters the compression module of the subsequent compression heat exchange module for compression. The cooling medium input end of the pre-filtration cooling module is connected to the output end of its cold first cooling medium storage module, and the cooling medium output end of its pre-filtration cooling module is connected to the output end of its hot first cooling medium storage module. The input end of the medium storage module is connected to the first cooling medium storage module, and the output end of the cooling medium of the third cold energy recovery module is connected to the input end of the first cold cooling medium storage module. The input end of the cooling medium of the third cold energy recovery module is connected to the output end of the first hot cooling medium storage module. In the energy storage stage, the first cooling medium stored in the first cold cooling medium storage module is sent to the pre-filtration cooling module to exchange heat with the compressed air output from the previous compression heat recovery module, cooling the compressed air. The heated first cooling medium after heat exchange is sent to the first hot cooling medium storage module for storage. In the energy release stage, the heated first cooling medium stored in the first hot cooling medium storage module is sent to the third cold energy recovery module to exchange heat with the gaseous pressurized air output from the second cold energy recovery module. The cooled first cooling medium after heat exchange is sent to the first cold cooling medium storage module for storage, ready for use in the energy storage stage.

[0109] In one example, the thermal storage medium module includes:

[0110] Cold thermal storage medium storage module, used to store thermal storage medium;

[0111] Thermal storage medium module, used to store heat-absorbing storage medium;

[0112] The heat storage medium input end of the compression heat energy recovery module is connected to the output end of the cold heat storage medium storage module, the heat storage medium output end of the compression heat energy recovery module is connected to the input end of the hot heat storage medium storage module, the input end of the cold heat storage medium storage module is connected to the heat storage medium output end of the air expansion preheating module, and the output end of the hot heat storage medium storage module is connected to the heat storage medium input end of the air expansion preheating module.

[0113] Specifically, the heat storage medium module includes a cold heat storage medium storage module and a hot heat storage medium storage module. The heat storage medium input end of the compression heat recovery module is connected to the output end of the cold heat storage medium storage module, and the heat storage medium output end of the compression heat recovery module is connected to the input end of the hot heat storage medium storage module. The input end of the cold heat storage medium storage module is connected to the heat storage medium output end of the air expansion preheating module, and the output end of the hot heat storage medium storage module is connected to the heat storage medium input end of the air expansion preheating module. During the energy storage phase, the heat storage medium stored in the cold heat storage medium storage module is transported to the compression module corresponding to the compression heat recovery module in all the compression heat recovery modules. The generated compressed air undergoes heat exchange, and the compressed heat energy in the compressed air is stored through a heat storage medium. The heated heat storage medium obtained after the heat exchange is transported to the hot heat storage medium storage module for storage. During the energy release phase, the heated heat storage medium stored in the hot heat storage medium storage module is transported to the air expansion preheater of all expansion power generation modules to exchange heat with the gaseous pressurized air transported by the third cold energy recovery module or the gaseous pressurized air output by the power generation module of the expansion power generation module above the air expansion preheater module. The compressed heat energy generated by the compression module is effectively utilized, and the low-temperature heat storage medium that has completed the heat exchange is transported to the cold heat storage medium storage module for storage, to be used in the energy storage phase.

[0114] In one example, the pre-cooling module includes:

[0115] The air precooling module is used to exchange heat between the second cooling medium, the third cooling medium output from the liquefaction cooling module, and the clean compressed air output from the final stage water cooling module.

[0116] A second cooling medium storage module is used to store the second cooling medium;

[0117] A second cooling medium storage module for storing the released second cooling medium;

[0118] The air cooling expansion module is used to expand and cool a portion of the clean compressed air output from the air precooling module to obtain expanded air.

[0119] The input terminal of the air precooling module is connected to the output terminal of the final stage water-cooling module of the compressor. The second cooling medium input terminal of the air precooler is connected to the output terminal of the cold second cooling medium storage module. The second cooling medium output terminal of the air precooling module is connected to the input terminal of the hot second cooling medium storage module. The input terminal of the cold second cooling medium storage module is connected to the cooling medium output terminal of the second cold energy recovery module. The output terminal of the hot second cooling medium storage module is connected to the cooling medium input terminal of the second cold energy recovery module. The input terminal of the air refrigeration expansion module is connected to the second output terminal of the air precooling module. The output terminal of the air refrigeration expansion module is connected to the low-temperature depressurized air input terminal of the liquid air storage module.

[0120] Specifically, the pre-cooling module includes an air pre-cooling module, a cold second cooling medium storage module, and a hot second cooling medium storage module. The input end of the air pre-cooling module is connected to the output end of the final stage water-cooling module of the compressor. The cooling medium input end of the air pre-cooling module is connected to the output end of the cold second cooling medium storage module. The cooling medium output end of the air pre-cooling module is connected to the input end of the hot second cooling medium storage module. The input end of the cold second cooling medium storage module is connected to the cooling medium output end of the second cold energy recovery module. The output end of the hot second cooling medium storage module is connected to the cooling medium input end of the second cold energy recovery module. The input end of the air refrigeration expansion module is connected to the first output end of the air pre-cooling module. The output end of the air refrigeration expansion module is connected to the low-temperature depressurized air input end of the liquid air storage module. During the energy storage stage, the second cooling medium stored in the cold second cooling medium storage module is input into the air pre-cooling module to exchange heat with the clean compressed air output from the final stage water-cooling module of the compressor, reducing the temperature of the clean compressed air. The heated second cooling medium obtained after the heat exchange is input into the hot second cooling medium storage module for storage. A portion of the pre-cooled clean compressed air output from the cold module is fed into the air refrigeration expansion module for expansion and refrigeration. The resulting expanded air is then fed into the liquid air storage module, where it combines with the flash air generated by the liquefaction module and the evaporated liquid air in the liquid air storage module to form a third cooling medium. This third cooling medium is then transported to the liquefaction cooling module, where it exchanges heat with another portion of the pre-cooled clean compressed air output from the air pre-cooling module. It is then sent back to the air pre-cooling module, where it, along with the second cooling medium, cools the clean compressed air output from the final stage water-cooling module. This process, combined with the third cooling medium which has undergone further heat exchange, further cools the air. The mass is delivered to the inlet of the first compression heat exchange module to provide clean air, thereby reducing the consumption of filter materials. During the energy release phase, the heated second cooling medium stored in the hot second cooling medium storage module is delivered to the second cold energy recovery module to exchange heat with the gaseous pressurized air output from the first cold energy recovery module, thereby increasing the temperature of the gaseous pressurized air. The cooled second cooling medium obtained after the heat exchange is input into the cold second cooling medium storage module for storage, recovering the cold energy in the second cooling medium and the gaseous pressurized air for use in the energy storage phase, thus realizing the recycling of cold energy and the second cooling medium.

[0121] In one example, the liquefaction module includes:

[0122] The air liquefaction module is used to exchange heat between the fourth cooling medium, the third cooling medium output from the liquid air storage module, and the clean compressed air output from the first output terminal of the air precooling module to obtain liquid air.

[0123] A fourth cooling medium storage module is used to store the fourth cooling medium;

[0124] A fourth cooling medium storage module for storing the released fourth cooling medium;

[0125] The liquid air expansion module is used to expand, depressurize, and cool the liquid air output from the air liquefaction module.

[0126] The input terminal of the air liquefaction module is connected to the first output terminal of the air precooling module; the cooling medium input terminal of the air liquefaction module is connected to the output terminal of the cold fourth cooling medium storage module; the cooling medium output terminal of the air liquefaction module is connected to the input terminal of the hot fourth cooling medium storage module; the input terminal of the cold fourth cooling medium storage module is connected to the cooling medium output terminal of the first cold energy recovery module; and the output terminal of the hot fourth cooling medium storage module is connected to the cooling medium input terminal of the first cold energy recovery unit. The input terminal of the liquid air expansion module is connected to the output terminal of the air liquefaction module, and the output terminal of the liquid air expansion module is connected to the liquid air storage module.

[0127] Specifically, the liquefaction cooling module includes an air liquefaction module, a cold fourth cooling medium storage module, a hot fourth cooling medium storage module, and an air cooling expansion module. The input end of the air liquefaction module is connected to the second output end of the air precooling module, the output end of the air liquefaction module is connected to the input end of the liquid air expansion module, the cooling medium input end of the air liquefaction module is connected to the output end of the cold fourth cooling medium storage module, the cooling medium output end of the air liquefaction module is connected to the input end of the hot fourth cooling medium storage module, the input end of the cold fourth cooling medium storage module is connected to the cooling medium output end of the first cooling recovery module, and the output end of the hot fourth cooling medium storage module is connected to the cooling medium input end of the first cooling recovery module. During the energy storage stage, the fourth cooling medium stored in the cold fourth cooling medium storage module is input to the air liquefaction module to exchange heat with the clean compressed air output from the air precooling module, liquefying the clean compressed air to obtain liquid air, which is then input into the liquid air storage module for storage. The heated fourth cooling medium obtained after the heat exchange is input into the hot fourth cooling medium storage module. The cooling medium is stored in four modules. When the liquid air storage module contains liquid air, the evaporated gas generated by the liquid air and the flash air generated after passing through the liquid air expansion module, along with the expanded air generated by the air cooling expansion module, form the third cooling medium in the liquid air storage module. This third cooling medium is then input into the air liquefaction module and, together with the fourth cooling medium, cools the clean compressed air output from the air precooling module. The third cooling medium, after heat exchange, is then sent to the air precooling module and, together with the second cooling medium, cools the clean compressed air output from the final stage water cooling module. During the energy release phase, the heated fourth cooling medium is input into the first cold energy recovery module and exchanges heat with the pressurized liquid air output from the liquid air storage module, causing the pressurized liquid air to vaporize and obtain gaseous pressurized air. Simultaneously, the fourth cooling medium obtained after heat exchange is sent to the cold fourth cooling medium module for storage. The fourth cooling medium and the cold energy recovered from the liquid air through the released fourth cooling medium are then recycled for use in the energy storage phase, realizing the recycling of cold energy and the fourth cooling medium.

[0128] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the invention. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of the present invention can be combined with each other.

[0129] Example 1

[0130] like Figure 2 As shown, a liquid air energy storage and power generation system according to the present invention includes:

[0131] Two compressors 1 and two compression heat recovery units 2, with the output of each compressor 1 connected to the input of the corresponding compression heat recovery unit 2; a compression end water cooler 3, with its input connected to the output of the second compression heat recovery unit 2; a molecular sieve precooler 4, with its input connected to the output of the first compression heat recovery unit 2; a molecular sieve 5, with its input connected to the output of the molecular sieve precooler 4 and its output connected to the input of the second compressor 1; a hot molecular sieve cooling medium storage tank 6, with its input connected to the cooling medium output of the molecular sieve precooler 4; and a cold molecular sieve cooling medium storage tank 7, with its output connected to the cooling medium input of the molecular sieve precooler 4. Connections include: a molecular sieve heat exchanger 8, whose cooling medium input end is connected to the output end of the hot molecular sieve cooling medium storage tank 6, and whose cooling medium output end is connected to the input end of the cold molecular sieve cooling medium storage tank 7; an air precooler 9, whose input end is connected to the output end of the compression terminal water cooler 3; an air refrigeration expander 10, whose input end is connected to the first output end of the air precooler 9; an air liquefaction unit 11, whose input end is connected to the second output end of the air precooler 9, and whose flash air output end is connected to the flash air input end of the air precooler 9; a liquid air expansion valve 12, whose input end is connected to the output end of the air liquefaction unit 11; and a liquid air storage tank 14, whose first input end is connected to the air refrigeration unit 7. The output end of the cold expander 10 is connected to the cold air expansion valve 12, and its second input end is connected to the output end of the liquid air expansion valve 12. Its flash air output end is connected to the flash air input end of the air liquefier 11. The hot shallow cold medium storage tank 15 has its input end connected to the shallow cold medium output end of the air precooler 9. The cold shallow cold medium storage tank 16 has its output end connected to the shallow cold medium input end of the air precooler 9. The hot deep cold medium storage tank 17 has its input end connected to the deep cold medium output end of the air liquefier 11. The cold deep cold medium storage tank 18 has its output end connected to the deep cold medium input end of the air liquefier 11. The hot heat storage medium storage module 19 has its input end connected to the heat storage of all the compression heat recovery units 2. The output ends of the media are connected; the cold heat storage medium storage module 20 has its output end connected to the heat storage medium input end of all the compression heat recovery units 2; the pressurization pump 25 has its input end connected to the output end of the liquid air storage tank 14; the cryogenic recovery unit 21 has its input end connected to the output end of the pressurization pump 25, its cryogenic medium input end is connected to the output end of the hot cryogenic medium storage tank 17, and its cryogenic medium output end is connected to the input end of the cold cryogenic medium storage tank 18; the shallow cryogenic recovery unit 22 has its input end connected to the output end of the cryogenic recovery unit 21, its shallow cryogenic medium input end is connected to the output end of the hot shallow cryogenic medium storage tank 15, and its shallow cryogenic medium output end is connected to the input end of the cold shallow cryogenic medium storage tank 16.The molecular sieve post-heat exchanger 8 has its input end connected to the output end of the shallow cooling recovery unit 22, its cooling medium input end connected to the output end of the hot molecular sieve cooling medium storage tank 6, and its cooling medium output end connected to the cold molecular sieve cooling medium storage tank 7. Two air expansion preheaters 23 and two turbine generator sets 24 are also included. The output end of each air expansion preheater 23 is connected to the input end of a corresponding turbine generator set 24. The output end of the first turbine generator set 24 is connected to the input end of the second air expansion preheater 23. The heat storage medium input end of each air expansion preheater 23 is connected to the output end of the hot heat storage medium storage module 19, and the heat storage medium output end of each air expansion preheater 23 is connected to the input end of the cold heat storage medium storage module 20. The input end of the first air expansion preheater 23 is connected to the output end of the molecular sieve post-heat exchanger 8. The second turbine generator set 24... The output of unit 24 is introduced into the atmosphere, or a third air expansion preheater 23 is added between the first air expansion preheater 23 and the molecular sieve post-heat exchanger 8. The output of the second turbine generator unit 24 is connected to the heat storage medium input of the third air expansion preheater 23, and the heat storage medium output of the third air expansion preheater 23 is connected to the atmosphere. The residual heat energy of the air output from the second turbine generator unit 24 is used to heat the gaseous and liquid air input to the third air expansion preheater 23, further recovering the residual heat in the air discharged from the second turbine generator unit 24, thereby improving the overall energy utilization efficiency of the system. After waste heat recovery, the air discharged from the last expansion power generation module can be directly discharged into the atmosphere. The heat storage medium, cryogenic medium, shallow cryogenic medium, and molecular sieve cooling medium are all liquid, and the output of their respective storage tanks are equipped with pumps for transporting each medium.

[0132] During the energy storage phase, i.e., the off-peak electricity consumption phase, the first compressor 1 compresses the outside air into high-temperature, high-pressure compressed air. The second compression heat recovery unit 2 exchanges heat between the high-temperature, high-pressure compressed air and the low-temperature heat storage medium output from the cold heat storage medium storage module 20, lowering the temperature of the compressed air. The compressed heat energy generated by the first compressor 1 is stored in the heat storage medium, resulting in a heated heat storage medium, which is then stored in the hot heat storage medium storage module 19, thus storing the compressed heat energy generated by the first compressor 1. The cooled compressed air is then fed into the molecular sieve precooler 4 and the output from the cold molecular sieve cooling medium storage tank 7. The compressed air undergoes heat exchange with a low-temperature molecular sieve cooling medium to further reduce its temperature, while simultaneously obtaining a heated molecular sieve cooling medium, which is stored in a hot molecular sieve cooling medium storage tank 6. The further cooled compressed air is then fed into a molecular sieve 5 for filtration to obtain clean compressed air. This clean compressed air is then fed into a second compressor 1 for recompression. The clean compressed air is then exchanged with a low-temperature heat storage medium output from a cold heat storage medium storage module 20 in a second heat recovery unit 2 to further reduce its temperature. The heat energy generated by the second compressor 1 is stored in the heat storage medium. The heated heat storage medium is stored in the heat storage medium storage module 19, thereby storing the compressed heat energy generated by the second compressor 1; the clean compressed air output from the second heat recovery unit 2 is input to the compression terminal water cooler 3 for cooling, and after the temperature of the clean compressed air is reduced, it is input to the air precooler 9 to exchange heat with the low-temperature shallow cold medium output from the cold shallow cold medium storage tank 16, further reducing the temperature of the compressed air, resulting in heated shallow cold medium and cooled clean compressed air; when the air liquefaction unit 11 can output low-temperature flash air to the air precooler 9, the low-temperature flash air is then used to exchange heat with the low-temperature cold medium. The warm, shallow-cooled medium together cools the clean compressed air output from the water cooler 3 at the end of the compression process, resulting in heated shallow-cooled medium, cooled clean compressed air, and heated flash air. The heated shallow-cooled medium is stored in the hot shallow-cooled medium storage tank 15, and the heated flash air is fed into the first compressor 1 for compression or directly discharged into the atmosphere. The compressed air is fed into the air refrigeration expander 10 through the first output end of the air precooler 9 for expansion and refrigeration. The expanded low-temperature depressurized air enters the liquid air storage tank 14 and combines with the flash air generated by the liquid air expansion valve to form low-temperature flash air.Clean compressed air is input into the air liquefaction unit 11 through the second output terminal of the air precooler 9. This air exchanges heat with the low-temperature cryogenic medium output from the cryogenic medium storage tank 18, resulting in liquid air and a heated cryogenic medium. When the liquid air storage tank 14 can output low-temperature flash air to the air liquefaction unit 11, the low-temperature flash air and the low-temperature cryogenic medium together cool the clean compressed air output from the air precooler 9, resulting in liquid air, a heated cryogenic medium, and heated flash air. The heated flash air is fed into the air precooler 9 for heat exchange, and the heated cryogenic medium is fed into the hot cryogenic medium storage tank 17 for storage. Liquid air is fed into the liquid air expansion valve 12 to reduce its pressure, and then the reduced-pressure liquid air is fed into the liquid air storage tank 14 for storage. As the liquid air is depressurized, it will also cool down due to the generation of flash air. The generated flash air is fed into the liquid air storage tank 14 and together with the low-temperature depressurized air output from the air refrigeration expander 10 to the liquid air storage tank 14, it replenishes the cooling capacity of the flash air.

[0133] like Figure 3 As shown, a liquid-air separator 13 can be added between the liquid-air expansion valve 12 and the liquid-air storage tank 14 according to actual conditions. Its output end is connected to the input end of the liquid-air storage tank 14, its first input end is connected to the output end of the air refrigeration expander 10, and its second input end is connected to the output end of the liquid-air expansion valve 12. After liquid-air separation of the liquid air output from the liquid-air expansion valve 12, the flash air and the low-temperature depressurized air output from the air refrigeration expander 10 are combined into the low-temperature evaporated gas in the liquid-air storage tank 14 through the first output end of the liquid-air separator 13 to form low-temperature flash air. The low-temperature flash air is sent back to the air liquefier 11 as a cold source supplement. The liquid air is input into the liquid-air storage tank 14 for storage through the second output end of the liquid-air separator 13.

[0134] During the energy release phase, i.e., the peak electricity consumption phase, the liquid air stored in the liquid air storage tank 14 is transported to the cryogenic recovery unit 21 by the pressurization pump 25 to exchange heat with the heated cryogenic medium output from the hot cryogenic medium storage tank 17, causing it to vaporize. The low-temperature cryogenic medium after heat exchange is then transported to the cold cryogenic medium storage tank 18 for storage, recovering the cold energy from the liquid air and regenerating the low-temperature cryogenic medium. The gaseous pressurized air output from the cryogenic recovery unit 21 is input into the shallow cryogenic recovery unit 22 to exchange heat with the heated shallow cryogenic medium output from the hot shallow cryogenic medium storage tank 15, raising the temperature of the gaseous pressurized air. The low-temperature shallow cryogenic medium after heat exchange is then transported to the cold shallow cryogenic medium storage tank 16 for storage, recovering the gaseous air. The cold energy in the pressurized air is recovered and regenerated into a low-temperature shallow-cooled medium. The gaseous pressurized air output from the shallow-cooled medium recovery unit 22 is fed into the molecular sieve post-heat exchanger 8 to exchange heat with the heated molecular sieve cooling medium output from the hot molecular sieve cooling medium storage tank 6, further increasing the temperature of the gaseous pressurized air. The low-temperature molecular sieve cooling medium after heat exchange is then transported to the cold molecular sieve cooling medium storage tank 7 for storage. The cold energy in the gaseous pressurized air is recovered and the low-temperature molecular sieve cooling medium is regenerated. At this point, the cold energy in the liquid air has been recovered and utilized three times, and the energy recovery is basically maximized. The gaseous pressurized air output from the molecular sieve post-heat exchanger 8 is fed into the first air expansion preheater 23 to exchange heat with the heated molecular sieve cooling medium output from the hot molecular sieve cooling medium storage tank 6. The heated heat storage medium output from the heat storage medium storage module 19 undergoes heat exchange, utilizing the compressed heat energy stored during the energy storage stage to reheat the gaseous pressurized air, increasing the inlet temperature of the first turbine generator set 24 and thus improving expansion efficiency to ensure the working efficiency of the first turbine generator set 24. The high-temperature gaseous pressurized air output from the first air expansion preheater 23 is input into the first turbine generator set 24 for power generation. The cooled, sub-high-pressure air after power generation is input into the second air expansion preheater 23 to exchange heat again with the heated heat storage medium output from the heat storage medium storage module 19. The high-temperature gaseous pressurized air output from the second air expansion preheater 23... Compressed air is input into the second turbine generator set 24 to generate electricity, supplementing power demand and playing a role in stabilizing the power grid and peak shaving. The thermal storage medium, cryogenic medium, and shallow cryogenic medium are all in liquid state. The description of the low temperature and temperature rise of the thermal storage medium, cryogenic medium, and shallow cryogenic medium is not limited to only two levels of thermal storage medium gradient. Two or more gradient levels can be flexibly defined according to the temperature change range of the energy storage working fluid throughout the entire process and the boiling points of the thermal storage medium, cryogenic medium, and shallow cryogenic medium. In this system, a control module can also be set up to control the operation of each device in the energy storage stage and the energy release stage, such as starting / stopping each device, and adjusting flow rate, pressure, and temperature.

[0135] Example 2

[0136] like Figure 4As shown, this embodiment provides a liquid air energy storage and power generation method, applied to the liquid air energy storage and power generation system described in Embodiment 1, including:

[0137] In the energy storage stage, compressed air is obtained by compressing air, and the compressed air is exchanged with the heat storage medium to obtain the heat storage medium that absorbs heat.

[0138] The compressed air that has completed heat exchange is cooled and filtered to obtain clean compressed air, which is then compressed again and exchanged with the heat storage medium again. The compressed heat energy in the compressed air or clean compressed air is stored through the heat storage medium that absorbs heat. The clean compressed air that has completed the last heat exchange is cooled and then delivered to the energy storage unit.

[0139] The cooled clean compressed air is liquefied through multi-stage cooling to obtain liquid air for storage.

[0140] During the energy release phase, the liquid air stored in the energy storage unit is pressurized and input into the power generation unit. The pressurized liquid air is then heated in multiple stages by the cooling medium recovered during the cooling process of the compression and filtration heat storage unit and the energy storage unit to obtain gaseous pressurized air. The gaseous pressurized air is then heated by the compressed heat energy stored in the heat storage medium, and the heated gaseous pressurized air is used to generate electricity. Cold energy is recovered during the multi-stage heating process by the cooling medium.

[0141] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A liquid air energy storage and power generation system, characterized in that, include: A compression filtration heat storage unit is used to compress air to obtain compressed air, and to exchange the compressed air with a heat storage medium to obtain the heat storage medium that absorbs heat. The compressed air that has completed heat exchange is cooled and filtered to obtain clean compressed air, and the clean compressed air is compressed again to exchange heat with the heat storage medium again. The compressed heat energy in the compressed air or the clean compressed air is stored by the heat storage medium that absorbs heat. The clean compressed air, after completing the final heat exchange, is cooled and then delivered to the energy storage unit; An energy storage unit is used to liquefy the cooled clean compressed air through multi-stage cooling to obtain liquid air and store it. The power generation unit, during the energy release phase, pressurizes the liquid air stored in the energy storage unit and inputs it into the power generation unit. It then uses a cooling medium recovered during the cooling process of the compression-filtration heat storage unit and the energy storage unit to perform multi-stage heating on the pressurized liquid air, obtaining gaseous pressurized air. The gaseous pressurized air is then heated by the compressed heat energy stored in the heat storage medium, and power is generated from the heated gaseous pressurized air. Cold energy is recovered during the multi-stage heating process using the cooling medium. The compression filtration heat storage unit includes: Multiple compression heat exchange modules are connected in sequence. Each compression heat exchange module is used to compress the air or the compressed air output by the previous compression heat exchange module, and to exchange the compressed air generated by each compression heat exchange module with the heat storage medium. A cooling and filtering module is disposed among the plurality of compression heat exchange modules. The cooling and filtering module is used to store a first cooling medium and to exchange heat between the compressed air output from the compression heat exchange module connected to the front end of the cooling and filtering module and the first cooling medium to obtain the released first cooling medium, which is then stored. The compressed air that has completed the heat exchange is then filtered. The filtered compressed air is then delivered to the compression heat exchange module connected to the rear end of the cooling and filtering module for compression heat exchange again. A final stage water-cooled module for compression, wherein the input end of the final stage water-cooled module is connected to the output end of the last compression heat exchange module, and is used to cool the clean compressed air output by the last compression heat exchange module by means of cooling water; A heat storage medium module is used to store the heat storage medium and the heat storage medium that absorbs heat, and to store the compressed heat energy by storing the heat storage medium that absorbs heat. The energy storage unit includes: The pre-cooling module is used to exchange heat between the clean compressed air output from the compression filtration heat storage unit and the second cooling medium and the third cooling medium output from the liquefaction cooling module, and to store the released second cooling medium; and to expand and cool a portion of the clean compressed air that has completed the heat exchange to obtain expanded air. The liquefaction cooling module is used to exchange heat between the clean compressed air that has completed the heat exchange and the fourth cooling medium and the third cooling medium to obtain the liquid air, and to store the released fourth cooling medium; and to perform expansion and decompression cooling on the liquid air. A liquid air storage module is used to store the liquid air that has completed the expansion, decompression and cooling process; the expanded air and the evaporated gas generated by the liquid air that has completed the expansion, decompression and cooling process are combined to form the third cooling medium and are sequentially transported to the liquefaction cooling module and the pre-cooling refrigeration module to exchange heat with another part of the clean compressed air that has completed the heat exchange and the clean compressed air output from the compression filter heat storage unit. The input terminal of the liquefaction cooling module is connected to the output terminal of the pre-cooling refrigeration module, the input terminal of the liquid air storage module is connected to the output terminal of the liquefaction cooling module, the low-temperature depressurized air input terminal of the liquid air storage module is connected to the low-temperature depressurized air output terminal of the pre-cooling refrigeration module, the third cooling medium output terminal of the liquid air storage module is connected to the third cooling medium input terminal of the liquefaction cooling module, and the third cooling medium output terminal of the liquefaction cooling module is connected to the third cooling medium input terminal of the pre-cooling refrigeration module.

2. The liquid air energy storage and power generation system according to claim 1, characterized in that, The power generation unit includes: The pressurization module is used to pressurize the liquid air stored in the liquid air storage module and then deliver it to the first cold energy recovery module; The first cold energy recovery module is used to exchange heat between the released fourth cooling medium and the pressurized liquid air, heat the liquid air to obtain gaseous pressurized air, and recover the cold energy in the liquid air through the released fourth cooling medium. The second cold energy recovery module is used to exchange heat between the released second cooling medium and the gaseous pressurized air to heat the gaseous pressurized air, and to recover the cold energy in the gaseous pressurized air through the released second cooling medium. The third cold energy recovery module is used to exchange heat again between the first cooling medium that has released cold and the gaseous pressurized air that has completed the heat exchange, to reheat the gaseous pressurized air, and to recover the cold energy in the gaseous pressurized air again through the first cooling medium that has released cold. A plurality of expansion power generation modules, each of the expansion power generation modules including one air expansion preheating module and one power generation module, wherein the output end of the air expansion preheating module is connected to the input end of the power generation module, and all the expansion power generation modules are connected in sequence; The air expansion preheating module is used to exchange heat between the heat storage medium that absorbs heat and the pressurized gaseous air that has completed the multi-stage heating. The power generation module is used to generate electricity from the gaseous pressurized air that has undergone heat exchange in the air expansion and preheating module. The input terminal of the pressurization module is connected to the output terminal of the liquid air storage module, the output terminal of the pressurization module is connected to the input terminal of the first cold energy recovery module, the output terminal of the first cold energy recovery module is connected to the input terminal of the second cold energy recovery module, the output terminal of the second cold energy recovery module is connected to the input terminal of the third cold energy recovery module, and the output terminal of the third cold energy recovery module is connected to the input terminal of the first air expansion preheating module.

3. The liquid air energy storage and power generation system according to claim 2, characterized in that, The compression heat exchange module includes: A compression module is used to compress the air or to recompress the filtered clean compressed air; A compression heat recovery module is used to exchange heat between the heat storage medium and the compressed air or the clean compressed air output by the compression module, and to recover the compressed heat energy through the heat storage medium. The output end of the compression module is connected to the input end of the compression heat recovery module.

4. The liquid air energy storage and power generation system according to claim 3, characterized in that, The cooling and filtration module includes: A pre-filter cooling module is used to exchange heat between the compressed air output from the compression heat exchange module connected to the pre-filter cooling module and the first cooling medium; the input end of the pre-filter cooling module is connected to the output end of the compression heat exchange module connected to the pre-filter. A filtration module is used to filter the compressed air output from the pre-filtration cooling module to obtain clean compressed air, and to deliver the clean compressed air to the compression heat exchange module connected to the downstream stage of the filtration module for compression; the input end of the filtration module is connected to the output end of the pre-filtration cooling module, and the output end of the filtration module is connected to the input end of the compression heat exchange module connected to the downstream stage. A first cooling medium storage module is used to store the first cooling medium; A first cooling medium storage module for storing the released first cooling medium; The cooling medium input terminal of the pre-filtration cooling module is connected to the output terminal of the cold first cooling medium storage module, the cooling medium output terminal of the pre-filtration cooling module is connected to the input terminal of the hot first cooling medium storage module, the cooling medium output terminal of the third cold energy recovery module is connected to the input terminal of the cold first cooling medium storage module, and the cooling medium input terminal of the third cold energy recovery module is connected to the output terminal of the hot first cooling medium storage module.

5. The liquid air energy storage and power generation system according to claim 4, characterized in that, The heat storage medium module includes: A cold heat storage medium storage module is used to store the heat storage medium; A thermal storage medium module for storing the heat-absorbing storage medium; The input end of the heat storage medium of the compression heat recovery module is connected to the output end of the cold heat storage medium module, the output end of the heat storage medium of the compression heat recovery module is connected to the input end of the hot heat storage medium module, the input end of the cold heat storage medium module is connected to the output end of the heat storage medium of the air expansion preheating module, and the output end of the hot heat storage medium module is connected to the input end of the heat storage medium of the air expansion preheating module.

6. The liquid air energy storage and power generation system according to claim 5, characterized in that, The pre-cooling module includes: An air precooling module is used to exchange heat between the second cooling medium, the third cooling medium output from the liquefaction cooling module, and the clean compressed air output from the final stage water cooling module. A second cooling medium storage module is used to store the second cooling medium; A second cooling medium storage module for storing the released second cooling medium; An air cooling expansion module is used to expand and cool a portion of the clean compressed air output from the air precooling module to obtain expanded air. The input terminal of the air precooling module is connected to the output terminal of the final stage water-cooling module of the compressor. The second cooling medium input terminal of the air precooling module is connected to the output terminal of the cold second cooling medium storage module. The second cooling medium output terminal of the air precooling module is connected to the input terminal of the hot second cooling medium storage module. The input terminal of the cold second cooling medium storage module is connected to the cooling medium output terminal of the second cold energy recovery module. The output terminal of the hot second cooling medium storage module is connected to the cooling medium input terminal of the second cold energy recovery module. The input terminal of the air refrigeration expansion module is connected to the second output terminal of the air precooling module. The output terminal of the air refrigeration expansion module is connected to the low-temperature depressurized air input terminal of the liquid air storage module.

7. The liquid air energy storage and power generation system according to claim 6, characterized in that, The liquefaction cooling module includes: An air liquefaction module is used to exchange heat between the fourth cooling medium, the third cooling medium output from the liquid air storage module, and the clean compressed air output from the first output terminal of the air precooling module to obtain the liquid air; A fourth cooling medium storage module is used to store the fourth cooling medium; A fourth cooling medium storage module for storing the released fourth cooling medium; A liquid air expansion module is used to expand, depressurize, and cool the liquid air output from the air liquefaction module; The input terminal of the air liquefaction module is connected to the first output terminal of the air precooling module; the cooling medium input terminal of the air liquefaction module is connected to the output terminal of the cold fourth cooling medium storage module; the cooling medium output terminal of the air liquefaction module is connected to the input terminal of the hot fourth cooling medium storage module; the input terminal of the cold fourth cooling medium storage module is connected to the cooling medium output terminal of the first cold energy recovery module; and the output terminal of the hot fourth cooling medium storage module is connected to the cooling medium input terminal of the first cold energy recovery module. The input terminal of the liquid air expansion module is connected to the output terminal of the air liquefaction module, and the output terminal of the liquid air expansion module is connected to the liquid air storage module.

8. A liquid air energy storage and power generation method, applied to the liquid air energy storage system according to any one of claims 1-7, characterized in that, include: In the energy storage stage, compressed air is obtained by compressing air, and the compressed air is exchanged with the heat storage medium to obtain the heat storage medium that absorbs heat. The compressed air that has completed heat exchange is cooled and filtered to obtain clean compressed air, and the clean compressed air is compressed again to exchange heat with the heat storage medium again. The compressed heat energy in the compressed air or the clean compressed air is stored by the heat storage medium that absorbs heat. The clean compressed air, after completing the final heat exchange, is cooled and then delivered to the energy storage unit; The clean compressed air that has undergone cooling is liquefied through multi-stage cooling to obtain liquid air, which is then stored. During the energy release phase, the liquid air stored in the energy storage unit is pressurized and input into the power generation unit. The pressurized liquid air is then heated in multiple stages using the cooling medium recovered during the cooling process of the compression filtration heat storage unit and the energy storage unit to obtain gaseous pressurized air. The gaseous pressurized air is then heated by the compressed heat energy stored in the heat storage medium, and power is generated from the heated gaseous pressurized air. Cold energy is recovered during the multi-stage heating process using the cooling medium.

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