Compressed air energy storage system capable of recycling condensate water and water supplementing method thereof

Abstract

The invention discloses a compressed air energy storage system capable of recycling condensate water and a water supplementing method of the compressed air energy storage system, and belongs to the technical field of energy storage systems.The compressed air energy storage system capable of recycling condensate water comprises an energy storage unit, an energy release unit, an air storage, a cooling tower and a liquid return pipeline; the energy storage unit comprises a compressor, a first heat exchanger, a second heat exchanger and a gas-liquid separator which are communicated in sequence, and the second heat exchanger is a gas-water heat exchanger; the cooling tower is communicated with the second heat exchanger and supplements cooling water to the second heat exchanger, one end of the liquid return pipeline is communicated with the gas-liquid separator, and the other end of the liquid return pipeline is communicated with the cooling tower. Therefore, in the energy storage process, condensed water can be separated out from air through the gas-liquid separator, and the condensed water is conveyed to the cooling tower through the liquid return pipeline so as to supplement water to the cooling tower and be used for heat exchange of the second heat exchanger, so that the condensed water separated out in the compression process can be fully recycled, the water resource utilization rate can be increased, and the problem of water resource shortage can be solved.

Description

Technical Field

[0001] The present application relates to the technical field of energy storage systems, and in particular to a compressed air energy storage system capable of recovering condensed water and a water replenishment method thereof. Background Art

[0002] Driven by the "dual carbon" strategy, my country's renewable energy sector has ushered in unprecedented development opportunities, especially new energy power generation technologies represented by wind power and photovoltaics have achieved rapid development. With the increasing penetration rate of new energy power generation, the "double high" characteristics of the new power system - a high proportion of renewable energy and a high proportion of power electronic equipment access - have become increasingly prominent, and the demand for new energy storage with long cycles and high safety has become more urgent. Among various energy storage technologies, compressed air energy storage is currently the main technology that can achieve hundreds of megawatts of application in addition to pumped storage. It has a stronger ability to support the stability of the power system, and has outstanding advantages such as long-term energy storage, short construction period, eco-friendly environment and high safety. It is an important carrier for building a new power system.

[0003] Among the related technologies, compressed air energy storage technology and applications are mostly focused on improving system efficiency and comprehensive utilization of waste heat, while ignoring the problem of compressed air water separation during the energy storage process, resulting in a large amount of water resource waste. Especially for areas with water shortages, the shortage of water resources has been seriously aggravated. At the same time, the condensed water separated from the compressed air comes into contact with the equipment in the system, which can easily cause damage to the equipment, affecting the performance and life of the equipment, thereby reducing the operating stability and reliability of the system. Summary of the invention

[0004] The present application aims to solve at least one of the technical problems existing in the related art. To this end, one purpose of the present application is to propose a compressed air energy storage system that can recycle condensed water. In the compressed air energy storage system that can recycle condensed water, during the energy storage process, air can precipitate condensed water through a gas-liquid separator, and the condensed water is sent to the cooling tower through a return liquid pipeline to replenish water to the cooling tower and used for heat exchange in the second heat exchanger, so that the condensed water precipitated during the compression process can be fully recycled and utilized, which can improve the utilization rate of water resources and optimize the problem of water resource shortage.

[0005] The present application also proposes a water replenishment method for an energy storage system.

[0006] According to the compressed air energy storage system with recyclable condensed water of the first aspect embodiment of the present application, the compressed air energy storage system with recyclable condensed water includes: an energy storage unit, an energy release unit, an air storage reservoir, a cooling tower and a liquid return pipeline, the energy storage unit includes: at least one energy storage unit, the energy storage unit includes a compressor, a first heat exchanger, a second heat exchanger and a gas-liquid separator connected in sequence, the second heat exchanger is constructed as an air-water heat exchanger; the air storage reservoir has an air-side pipeline, the air-side pipeline can be selectively connected to the energy storage unit for energy storage, or connected to the energy release unit for energy release; the cooling tower is connected to the second heat exchanger and replenishes cooling water to the second heat exchanger, one end of the liquid return pipeline is connected to the gas-liquid separator, and the other end is connected to the cooling tower to replenish water to the cooling tower.

[0007] According to the compressed air energy storage system with recyclable condensed water of the present application, the condensed water in the compressed air is separated out by a gas-liquid separator, and is transported to the cooling tower through a return liquid pipeline to replenish the cooling tower, so that the cooling tower can continuously provide cooling water to the second heat exchanger for heat exchange, thereby achieving full recycling of the condensed water separated out during the compression process, improving the utilization rate of water resources, and effectively alleviating the problem of water resource shortage. In addition, by separating and removing the moisture in the compressed air and improving the dryness of the air, it is also helpful to protect the compressor and other equipment from moisture damage, which is beneficial to improving the performance and life of the equipment, and improving the operating stability and reliability of the compressed air energy storage system with recyclable condensed water, while improving the exhaust air quality and environmental protection.

[0008] According to some embodiments of the present application, the second heat exchanger includes: a cooling water inlet and a cooling water outlet, the cooling water inlet is connected to the cooling tower outlet through a first pipeline, and the cooling water outlet is connected to the cooling tower inlet through a second pipeline.

[0009] Furthermore, the cooling tower is provided with a first water pump, which is arranged at the inlet of the cooling tower and / or the outlet of the cooling tower and is suitable for communicating with the first pipeline or the second pipeline.

[0010] In some embodiments, when there are multiple energy storage units, multiple first pipelines are connected in parallel, and multiple second pipelines are connected in parallel.

[0011] According to some embodiments of the present application, the liquid return pipeline includes a liquid return pipe and a second water pump, the liquid return pipe is connected to the second water pump, and the second water pump is used to replenish water to the cooling tower.

[0012] Furthermore, the liquid return pipe is constructed as an underground pipe.

[0013] In some embodiments, the liquid return pipeline further includes: a filter, which is disposed between the liquid return pipe and the cooling tower and is suitable for filtering water returning from the liquid return pipe.

[0014] According to some embodiments of the present application, the compressed air energy storage system with recyclable condensed water also includes: a liquid storage tank, and the return liquid pipeline also includes: a first branch and a second branch, one end of the first branch is connected to the filter, and the other end is connected to the cooling tower, one end of the second branch is connected to the filter, and the other end is connected to the liquid storage tank.

[0015] Furthermore, the liquid return pipeline also includes: a third branch, one end of the third branch is connected to the liquid storage tank, and the other end is connected to the cooling tower. The third branch is provided with a third water pump for the liquid storage tank to replenish water to the cooling tower.

[0016] In some embodiments, a first valve is disposed on the first branch, and a second valve is disposed on the second branch.

[0017] Furthermore, a liquid level sensor is also provided on the cooling tower. The liquid level sensor is electrically connected to the first valve and the second valve and is suitable for controlling the first valve and the second valve to selectively open and close.

[0018] According to some embodiments of the present application, the energy release machine group includes: at least one energy release unit, and the energy release unit includes an expander and a heater connected in sequence.

[0019] According to some embodiments of the present application, the compressed air energy storage system with recoverable condensed water further includes: a low-temperature heat storage device and a high-temperature heat storage device, and both the low-temperature heat storage device and the high-temperature heat storage device are connected to the heater and the first heat exchanger.

[0020] The water replenishment method for an energy storage system according to an embodiment of the second aspect of the present application is applicable to a compressed air energy storage system with recyclable condensed water according to any one of the above embodiments, and the water replenishment method for the energy storage system comprises: obtaining the liquid level of a cooling tower; when the liquid level reaches a first threshold, opening a first valve and closing a second valve to replenish water to the cooling tower; when the liquid level reaches a second threshold, opening the second valve and closing the first valve to supply water to a liquid storage tank; wherein the first threshold is lower than the second threshold.

[0021] Furthermore, the water replenishment method of the energy storage system also includes: when the liquid level reaches the first threshold, if the energy storage unit stops storing energy, the liquid storage tank replenishes water to the cooling tower until the liquid level reaches the second threshold.

[0022] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0024] Figure 1 is a schematic diagram of a compressed air energy storage system capable of recovering condensed water according to some embodiments of the present application;

[0025] Figure 2 It is a flow chart of a water replenishment method for an energy storage system according to some embodiments of the present application.

[0026] Reference numerals:

[0027] 100. Compressed air energy storage system with recyclable condensed water;

[0028] 11. compressor; 12. first heat exchanger; 13. second heat exchanger; 14. gas-liquid separator;

[0029] 21. expander; 22. heater;

[0030] 30. Gas storage;

[0031] 40. Cooling tower; 41. First pipeline; 42. Second pipeline; 43. First water pump; 44. Liquid level sensor;

[0032] 51. liquid return pipe; 52. second water pump; 53. filter; 54. first branch; 55. second branch; 56. third branch; 57. third water pump; 58. first valve; 59. second valve;

[0033] 60. Liquid storage tank;

[0034] 70. Low temperature heat storage device;

[0035] 80. High temperature heat storage device;

[0036] 91. Motor; 92. Generator. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0038] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by technicians in the technical field of this application; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned drawings and any variations thereof are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship.

[0039] Reference to "embodiment" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments.

[0040] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "attached" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0041] The term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the associated objects before and after are in an "or" relationship.

[0042] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device are only exemplary descriptions and should not constitute any limitation to the present application.

[0043] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0044] In the description of the present application, a first feature being “on” or “under” a second feature may include that the first and second features are directly in contact with each other, or may include that the first and second features are not in direct contact with each other but are in contact with each other via another feature therebetween.

[0045] In the description of the present application, “above”, “over” and “above” a first feature to a second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is horizontally higher than the second feature.

[0046] The term "plurality" used in the present application refers to two or more (including two).

[0047] Reference below Figure 1 and Figure 2 A compressed air energy storage system 100 capable of recovering condensed water and a water replenishment method for the energy storage system according to an embodiment of the present application are described.

[0048] like Figure 1 As shown, according to the compressed air energy storage system 100 with recyclable condensed water of the first aspect embodiment of the present application, the compressed air energy storage system 100 with recyclable condensed water includes: an energy storage unit, an energy release unit, an air storage reservoir 30, a cooling tower 40 and a liquid return pipeline.

[0049] Among them, the energy storage unit includes: at least one energy storage unit, the energy storage unit includes a compressor 11, a first heat exchanger 12, a second heat exchanger 13 and a gas-liquid separator 14 connected in sequence, the second heat exchanger 13 is constructed as a gas-water heat exchanger; the gas storage reservoir 30 has an air-side pipeline, the air-side pipeline can be selectively connected to the energy storage unit to store energy, or connected to the energy release unit to release energy; the cooling tower 40 is connected to the second heat exchanger 13, and cooling water is added to the second heat exchanger 13, one end of the return liquid pipeline is connected to the gas-liquid separator 14, and the other end is connected to the cooling tower 40 to replenish water to the cooling tower 40.

[0050] Specifically, the gas storage reservoir 30 can be selectively connected to the energy storage unit or the energy release unit through the gas side pipeline to respectively realize the energy storage and energy release of the compressed air energy storage system 100 with recoverable condensed water. Among them, the energy storage unit can include one or more energy storage units, each of which includes a compressor 11, a first heat exchanger 12, a second heat exchanger 13 and a gas-liquid separator 14 connected in sequence, and the second heat exchanger 13 is configured as an air-water heat exchanger. During the energy storage process, the air first enters the compressor 11. The compressor 11 compresses the air to a high pressure to store the excess power of the motor 91 and other equipment when the load is low. A large amount of heat is generated during the compression process. This heat is recovered and stored through the first heat exchanger 12 for subsequent use. Then, the high-pressure air enters the second heat exchanger 13, i.e., the air-to-water heat exchanger. The air-to-water heat exchanger uses cooling water to lower the air temperature and heats the cooling water at the same time to achieve energy transfer. The cooled air enters the gas-liquid separator 14, where the water and liquid substances are separated, and the dry high-pressure gas is stored in the gas storage reservoir 30 for energy storage. When energy needs to be released, the high-pressure air in the gas storage reservoir 30 enters the energy release unit through the gas side pipeline. In the energy release unit, the compression heat stored in the first heat exchanger 12 during the energy storage process can be used to heat the air to improve the energy storage efficiency. The high-pressure air is converted into electrical energy or other forms of energy through heating and expansion to operate the generator 92 and other equipment, thereby realizing the reuse of the stored energy.

[0051] It should be pointed out that the compressed air energy storage system 100 capable of recovering condensed water in the present application has a cooling tower 40 and a liquid return pipeline, wherein the cooling tower 40 is suitable for replenishing cooling water to the second heat exchanger 13 in the energy storage unit to exchange heat with the compressed air. One end of the liquid return pipeline is connected to the gas-liquid separator 14 in the energy storage unit, and the other end is connected to the cooling tower 40. The liquid return pipeline can deliver the water and liquid substances separated from the gas-liquid separator 14 to the cooling tower 40 to replenish the cooling tower 40 for use as circulating cooling water, thereby realizing the recovery and utilization of the condensed water precipitated during the compression process in the energy storage process.

[0052] According to the compressed air energy storage system 100 with recyclable condensed water of the present application, the condensed water in the compressed air is precipitated by the gas-liquid separator 14, and is transported to the cooling tower 40 through the return liquid pipeline to replenish water to the cooling tower 40, so that the cooling tower 40 can continue to provide cooling water for the second heat exchanger 13 for heat exchange, thereby achieving full recycling of the condensed water precipitated during the compression process, improving the utilization rate of water resources, and effectively alleviating the problem of water resource shortage. In addition, by separating and removing moisture from the compressed air and improving air dryness, it is also helpful to protect the compressor 11 and other equipment from moisture damage, which is beneficial to improving equipment performance and life, and improving the operating stability and reliability of the compressed air energy storage system 100 with recyclable condensed water, while improving the exhaust air quality and environmental protection.

[0053] like Figure 1 As shown, according to some embodiments of the present application, the second heat exchanger 13 includes: a cooling water inlet and a cooling water outlet, the cooling water inlet is connected to the cooling tower outlet through a first pipeline 41, and the cooling water outlet is connected to the cooling tower inlet through a second pipeline 42.

[0054] Specifically, the cooling water inlet of the second heat exchanger 13 in each energy storage unit is connected to the cooling tower outlet through the first pipeline 41. The cooling water after evaporation and cooling in the cooling tower 40 enters the cooling water inlet of the second heat exchanger 13 through the first pipeline 41. Inside the heat exchanger, the cooling water exchanges heat with the compressed hot air, absorbs the heat in the air, thereby reducing the air temperature, and at the same time, the temperature of the cooling water itself increases. The cooling water outlet of the second heat exchanger 13 is connected to the cooling tower inlet through the second pipeline 42, so that the cooling water heated after heat exchange with the air can flow out from the cooling water outlet of the second heat exchanger 13 and return to the cooling tower 40 through the second pipeline 42. In the cooling tower 40, the cooling water is cooled by evaporation to prepare for the next round of heat exchange process. The second heat exchanger 13 is connected to the cooling tower 40 through the first pipeline 41 and the second pipeline 42, which ensures the continuous circulation of cooling water in the compressed air energy storage system 100 with recyclable condensed water, and fully utilizes the evaporation cooling effect of the cooling tower 40 and the heat exchange capacity of the second heat exchanger 13, thereby achieving effective cooling of the compressed air and improving the energy utilization efficiency of the entire system.

[0055] In addition, in some specific embodiments of the present application, the temperature of the cooling tower inlet and the cooling tower outlet is controlled in the range of about 30°C to 35°C. When the temperature of the cooling tower inlet and the cooling tower outlet is much lower than 30°C, such as 20°C, 15°C or 10°C, the temperature of the cooling tower inlet and the cooling tower outlet is too low. When the working condition of the first heat exchanger 12 remains unchanged, in order to achieve the too low temperature of the cooling tower inlet and the cooling tower outlet, the cooling tower 40 may increase energy consumption, but reduce the operating efficiency of the entire compressed air energy storage system 100 for recovering condensed water; when the temperature of the cooling tower inlet and the cooling tower outlet is much higher than 35°C, such as 45°C, 50°C or 55°C, the temperature of the cooling tower inlet and the cooling tower outlet is too high, which will cause the cooling effect of the cooling water on the compressed air to be poor, or even unable to be cooled, thereby reducing the thermal efficiency and energy storage density of the compressed air energy storage system 100 for recovering condensed water. By setting the temperature of the cooling tower inlet and the cooling tower outlet to the above range, such as 30°C, 32°C or 35°C, the temperature of the cooling tower inlet and the cooling tower outlet is controlled within an appropriate range, which helps to ensure that the cooling water can effectively release heat when passing through the cooling tower 40, and ensures that the cooling tower 40 can effectively dissipate heat and maintain a suitable operating temperature, which is beneficial to optimizing the operating efficiency and stability of the compressed air energy storage system 100 with recoverable condensed water.

[0056] like Figure 1 As shown, according to some embodiments of the present application, a first water pump 43 is provided on the cooling tower 40 , and the first water pump 43 is arranged at the cooling tower inlet and / or the cooling tower outlet, and is suitable for communicating with the first pipeline 41 or the second pipeline 42 .

[0057] Specifically, the cooling tower 40 may be provided with a first water pump 43, and the arrangement of the first water pump 43 may be configured such that only the cooling tower inlet is provided with the first water pump 43, while the cooling tower outlet is not provided with the first water pump 43, the arrangement of the first water pump 43 may also be configured such that only the cooling tower outlet is provided with the first water pump 43, while the cooling tower inlet is not provided with the first water pump 43, and the arrangement of the first water pump 43 may also be configured such that both the cooling tower inlet and the cooling tower outlet are provided with the first water pump 43. The first water pump 43 may provide power for the flow of cooling water, so as to ensure that the cooling water flows smoothly from the cooling tower outlet to the cooling water inlet of the second heat exchanger 13, and ensure that the cooling water after heat exchange flows from the cooling water outlet of the second heat exchanger 13 to the cooling tower inlet, thereby ensuring the circulation of cooling water between the cooling tower 40 and the second heat exchanger 13.

[0058] In addition, in some embodiments, the first water pump 43 can also play a role in regulating the flow rate. For example, by adjusting the speed or opening degree of the first water pump 43, the flow rate of cooling water can be accurately controlled. In this way, the cooling water regulation ability of the compressed air energy storage system 100 with recyclable condensed water for different working conditions can be enhanced, and the flexibility of the compressed air energy storage system 100 with recyclable condensed water can be improved. It can meet the cooling requirements under different working conditions, which helps to ensure that the compressed air energy storage system 100 with recyclable condensed water can maintain the best operating state under various conditions, thereby improving the efficiency of the compressed air energy storage system 100 with recyclable condensed water. For example, in high temperature weather in summer, the circulation speed and cooling effect of cooling water can be increased by increasing the speed of the first water pump 43; while in low temperature weather in winter, the speed of the first water pump 43 can be reduced to save energy and avoid overcooling.

[0059] like Figure 1 As shown, according to some embodiments of the present application, when there are multiple energy storage units, multiple first pipelines 41 are connected in parallel, and multiple second pipelines 42 are connected in parallel.

[0060] Specifically, the number of energy storage units can be configured to be multiple, so that the air reaches a higher pressure by compressing the air multiple times, thereby storing more energy. When the number of energy storage units is configured to be multiple, the first pipelines 41 of the multiple energy storage units are connected in parallel, and the second pipelines 42 of the multiple energy storage units are connected in parallel. For example, if the number of energy storage units is two, then the corresponding two first pipelines 41 are connected in parallel and the two second pipelines 42 are connected in parallel. If the number of energy storage units is three, then the corresponding three first pipelines 41 are connected in parallel and the three second pipelines 42 are connected in parallel. By arranging multiple first pipelines 41 in parallel, so that the cooling water inlet of the second heat exchanger 13 of each energy storage unit is connected to the cooling tower outlet, it can be ensured that the second heat exchanger 13 of each energy storage unit can obtain cooling water from the cooling tower 40. By arranging multiple second pipelines 42 in parallel so that the cooling water outlet of the second heat exchanger 13 of each energy storage unit is connected to the inlet of the cooling tower, it can be ensured that the cooling water after heat exchange in the second heat exchanger 13 of each energy storage unit can flow smoothly back to the cooling tower 40 for cooling, so as to prepare for the next round of cooling of the second heat exchanger 13. Therefore, by connecting multiple first pipelines 41 in parallel and multiple second pipelines 42 in parallel, the cooling needs of each energy storage unit can be fully met, and the thermal efficiency of the entire compressed air energy storage system 100 with recoverable condensed water can be effectively improved.

[0061] In addition, the parallel arrangement of multiple first pipelines 41 and multiple second pipelines 42 can also improve the flexibility and scalability of the compressed air energy storage system 100 with recoverable condensed water. When a new energy storage unit needs to be added, only the corresponding first pipeline 41, second pipeline 42 and connectors need to be added, without the need for large-scale modification of the existing compressed air energy storage system 100 with recoverable condensed water.

[0062] like Figure 1 As shown, according to some embodiments of the present application, the liquid return pipeline includes a liquid return pipe 51 and a second water pump 52 . The liquid return pipe 51 is connected to the second water pump 52 , and the second water pump 52 is used to replenish water to the cooling tower 40 .

[0063] Specifically, the two ends of the liquid return pipe 51 are respectively connected to the gas-liquid separator 14 and the cooling tower 40 to provide a circulation channel for the liquid separated by the gas-liquid separator 14. The second water pump 52 is connected to the liquid return pipe 51 to provide power for the liquid in the liquid return pipe 51 to ensure that the liquid can be quickly and effectively transported to the cooling tower 40 when needed. For example, when the cooling water in the cooling tower 40 is reduced due to evaporation, leakage or other reasons, the second water pump 52 can timely pump the liquid flowing into the liquid return pipe 51 from the gas-liquid separator 14 to the cooling tower 40 to replenish the cooling tower 40 with water, thereby maintaining a normal amount of cooling water in the cooling tower 40 to ensure a good cooling effect of the second heat exchanger 13.

[0064] Similarly, in some embodiments, the second water pump 52 can also play a role in regulating flow. By adjusting the rotation speed or opening degree of the second water pump 52, the liquid flow in the return liquid pipeline can be accurately controlled to meet the cooling requirements under different working conditions, thereby improving the flexibility and adaptability of the compressed air energy storage system 100 with recoverable condensed water.

[0065] like Figure 1 As shown, according to some embodiments of the present application, the liquid return pipe 51 is constructed as an underground pipe.

[0066] Specifically, the liquid return pipe 51 can be constructed as an underground pipe, which refers to a pipe installed underground, which can use the natural heat capacity of underground soil or rock for heat exchange to achieve heat dissipation or heat absorption of the liquid in the pipe. In the heat dissipation mode, when the liquid separated by the gas-liquid separator 14 flows into the underground pipe, the underground pipe can transfer the heat of the liquid in the pipe to the soil, so that the liquid is cooled down; in the heat absorption mode, the underground pipe absorbs heat from the soil, heats the liquid in the pipe, and heats the liquid. By constructing the return liquid pipe 51 as an underground pipe, on the one hand, since the natural heat capacity of soil or rock is relatively large, the liquid can quickly absorb or release heat by exchanging heat with the underground soil through the underground pipe, thereby achieving efficient heat exchange; on the second hand, the underground pipe utilizes the heat capacity of the natural environment such as soil or rock, and does not require additional energy input, so it can effectively save energy consumption. At the same time, since the underground pipe is buried underground, the impact on the surface landscape and ecological environment is relatively small, which is in line with the green and environmentally friendly sustainable development concept; on the third hand, compared with the surface temperature, the underground temperature is more stable. Therefore, in the climate with different temperatures in the four seasons, the soil can provide stable temperature control for the buried pipe, thereby helping to improve the temperature stability of the liquid flowing from the buried pipe into the cooling tower 40, which is beneficial to improving the thermal efficiency and operation stability of the compressed air energy storage system 100 with recoverable condensed water.

[0067] In addition, in some specific embodiments of the present application, the material structure of the buried pipe is steel, high-density polyethylene or polyvinyl chloride. Steel, high-density polyethylene and polyvinyl chloride have the advantages of good corrosion resistance, high strength, good thermal conductivity, etc., which are beneficial to improving the heat exchange performance and life of the buried pipe during long-term use.

[0068] like Figure 1 As shown, according to some embodiments of the present application, the liquid return pipeline further includes: a filter 53 , which is disposed between the liquid return pipe 51 and the cooling tower 40 and is suitable for filtering the water returning from the liquid return pipe 51 .

[0069] Specifically, the filter 53 is disposed between the liquid return pipe 51 and the cooling tower 40, that is, the liquid flows from the gas-liquid separator 14 into the liquid return pipe 51 and enters the cooling tower 40 through the liquid return pipe 51. When the liquid flows from the liquid return pipe 51 into the filter 53, impurities and pollutants in the liquid can be intercepted by the filter screen or filter material inside the filter 53, while the purified water after filtration continues to flow and enters the cooling tower 40 for the next cooling process. By arranging a filter 53 between the return pipe 51 and the cooling tower 40, it is ensured that the liquid has been filtered before entering the cooling tower 40, thereby improving the purity of the liquid entering the cooling tower 40. In this way, on the one hand, it is conducive to ensuring good fluidity and stability of the cooling water, thereby improving the stability and reliability of the entire compressed air energy storage system 100 with recoverable condensed water; on the other hand, it can also avoid clogging and damage to the cooling tower 40 and the second heat exchanger 13 caused by impurities and pollutants in the liquid before filtration, thereby helping to ensure the performance and service life of the cooling tower 40 and the second heat exchanger 13, etc., and ensuring the stable operation and high efficiency of the compressed air energy storage system 100 with recoverable condensed water.

[0070] In some embodiments, the filter 53 can be constructed in multiple ways, and each of them can be constructed in different ways. For example, at least one of the multiple filters 53 can be constructed as a mechanical filter to remove suspended matter, particulate matter, etc. in the liquid; at least one of the multiple filters 53 can be constructed as an activated carbon filter to remove organic matter, residual chlorine and other chemical pollutants in the liquid; at least one of the multiple filters 53 can be constructed as a precision filter to further remove tiny particles and bacteria. By cooperating with different types of filters 53, the filtering effect can be further enhanced, and the cleanliness of the liquid in the return pipe 51 can be further improved.

[0071] like Figure 1 As shown, according to some embodiments of the present application, the compressed air energy storage system 100 with recyclable condensed water also includes: a liquid storage tank 60, and the return liquid pipeline also includes: a first branch 54 and a second branch 55, one end of the first branch 54 is connected to the filter 53, and the other end is connected to the cooling tower 40, one end of the second branch 55 is connected to the filter 53, and the other end is connected to the liquid storage tank 60.

[0072] Specifically, the two ends of the first branch 54 in the liquid return pipeline are respectively connected to the filter 53 and the cooling tower 40, and the first branch 54 is used to transport the liquid in the liquid return pipe 51 to the cooling tower 40 after filtering; the two ends of the second branch 55 in the liquid return pipeline are respectively connected to the filter 53 and the liquid storage tank 60, and the second branch 55 is used to transport the filtered liquid to the liquid storage tank 60 for storage and standby. In the energy storage stage, the gas-liquid separator 14 in the energy storage unit separates the moisture in the compressed air, and enters the filter 53 through the liquid return pipe 51 for filtration. The filtered moisture can have two flow paths: the first path is to enter the cooling tower 40 through the first branch 54, so as to be used for the cooling tower 40 to circulate water to the second heat exchanger 13, and the second path is to flow into the liquid storage tank 60 through the second branch 55 for storage and standby. The specific flow path of the filtered water can be determined according to the amount of water in the cooling tower 40. Specifically, the condensed water precipitated and filtered during the compression process can first flow into the cooling tower 40 along the first path to replenish the cooling tower 40. When the amount of water in the cooling tower 40 reaches the preset upper limit, the return pipe 51 completes the replenishment of water to the cooling tower 40. At this time, if the compression process has not yet ended, the excess condensed water precipitated and filtered during the compression process will enter the liquid storage tank 60 along the second path for storage and be used as a backup water source for the compressed air energy storage system 100 with recyclable condensed water. Through the multi-branch setting of the first branch 54 and the second branch 55, flexible scheduling of the recovered condensed water can be achieved, the utilization of water resources can be further optimized, and it is helpful to improve the cooling efficiency and stability of the compressed air energy storage system 100 with recyclable condensed water.

[0073] like Figure 1 As shown, according to some embodiments of the present application, the liquid return pipeline also includes: a third branch 56, one end of the third branch 56 is connected to the liquid storage tank 60, and the other end is connected to the cooling tower 40, and the third branch 56 is provided with a third water pump 57 for the liquid storage tank 60 to replenish water to the cooling tower 40.

[0074] Specifically, the two ends of the third branch 56 in the return liquid pipeline are connected to the liquid storage tank 60 and the cooling tower 40 respectively, and the third branch 56 is provided with a third water pump 57, so that under the drive of the third water pump 57, the water source stored in the liquid storage tank 60 can be directly pumped to the cooling tower 40 through the third branch 56, so as to realize timely water replenishment to the cooling tower 40, thereby maintaining sufficient water volume in the cooling tower 40.

[0075] It is understandable that, in the energy storage stage, the cooling tower 40 can first use the circulating cooling water flowing through the second heat exchanger 13 and the water separated by the gas-liquid separator 14 to replenish and ensure the water volume in the cooling tower 40. The third branch 56 is used as a backup water replenishment path to replenish water to the cooling tower 40, and it is not limited to the energy storage stage or the non-energy storage stage. For example, in the energy storage stage, if the cooling tower 40 replenishes water by recovering the water separated by the gas-liquid separator 14 at a relatively slow speed, the water source stored in the liquid storage tank 60 can be appropriately introduced into the cooling tower 40 to speed up the water replenishment speed of the cooling tower 40; after the energy storage is completed, that is, in the non-energy storage stage, when the water volume in the cooling tower 40 is less due to the short compression time and the amount of condensed water recovered is small, or due to evaporation and other reasons, it is lower than the preset upper limit value, then the water source stored in the liquid storage tank 60 can also be replenished into the cooling tower 40, and the water volume in the cooling tower 40 reaches the preset upper limit value,

[0076] By utilizing the liquid storage tank 60 to store the excess water released during the compression process as an effective guarantee for backup water replenishment of the cooling tower 40, it is possible to ensure that the cooling tower 40 always has sufficient water to ensure the overall thermal efficiency and operational reliability of the compressed air energy storage system 100 that can recover condensed water, while achieving full utilization and optimal configuration of the condensed water released during the compression process.

[0077] like Figure 1 As shown, according to some embodiments of the present application, a first valve 58 is provided on the first branch 54 , and a second valve 59 is provided on the second branch 55 .

[0078] Specifically, the first valve 58 is arranged on the first branch 54, and the first valve 58 can be used for the conduction, closing and flow control of the first branch 54; similarly, the second valve 59 is arranged on the second branch 55, and the second valve 59 can be used for the conduction, closing and flow control of the second branch 55. When the first valve 58 is opened and the second valve 59 is closed, the corresponding filter 53 and the cooling tower 40 are connected, and the filter 53 and the liquid storage tank 60 are closed, then the liquid in the return pipe 51 is filtered by the filter 53 and flows to the cooling tower 40 to replenish the cooling tower 40. When the second valve 59 is opened and the first valve 58 is closed, the corresponding filter 53 and the liquid storage tank 60 are connected, and the filter 53 and the cooling tower 40 are closed, then the liquid in the return pipe 51 is filtered by the filter 53 and flows to the liquid storage tank 60 for storage and standby. Therefore, by switching the opening and closing states of the first valve 58 and the second valve 59, the return liquid pipe 51 can be flexibly switched between replenishing water to the cooling tower 40 and providing storage water to the liquid storage tank 60, which can effectively improve the working flexibility and reliability of the compressed air energy storage system 100 that can recover condensed water.

[0079] In addition, by adjusting the first valve 58, the flow rate of the first branch 54 can be accurately controlled, and by controlling the opening of the second valve 59, the flow rate of the second branch 55 can be accurately controlled, thereby controlling the speed of the return pipe 51 replenishing water to the cooling tower 40 and the liquid storage tank 60. For example, when the water precipitated during the compression process of the energy storage unit is relatively large, and the flow rate in the return pipe 51 is large, and the amount of water in the cooling tower 40 tends to approach the preset upper limit value, the opening of the first valve 58 can be appropriately reduced to slow down the flow rate and speed of the liquid flowing to the cooling tower 40, so as to improve the control accuracy of replenishing the water in the cooling tower 40 to the preset upper limit value. By adjusting the opening of the first valve 58 and the second valve 59, the flow path and flow rate of the condensed water recovered in the energy storage stage can be further flexibly dispatched, and the cooling effect and resource utilization can be further optimized.

[0080] like Figure 1 As shown, according to some embodiments of the present application, a liquid level sensor 44 is further provided on the cooling tower 40. The liquid level sensor 44 is electrically connected to the first valve 58 and the second valve 59, and is suitable for controlling the first valve 58 and the second valve 59 to selectively open and close.

[0081] Specifically, a liquid level sensor 44 is provided on the cooling tower 40, and the liquid level sensor 44 can monitor the liquid level of the cooling water in the cooling tower 40 in real time, and the liquid level sensor 44 is electrically connected to the first valve 58 and the second valve 59, and the liquid level sensor 44 can convert the detected liquid level in the cooling tower 40 into an electrical signal and send it to the control system, and the control system automatically adjusts the opening of the first valve 58 and the second valve 59 according to the preset logic algorithm to achieve timely replenishment and reasonable distribution of cooling water. Exemplarily, when the liquid level sensor 44 detects that the liquid level in the cooling tower 40 is lower than the preset upper limit value, the first valve 58 can be controlled to open, and the second valve 59 can be controlled to close, so that the condensed water precipitated during the compression process flows only into the cooling tower 40 after filtering, so as to ensure that the cooling tower 40 is quickly replenished with water; when the liquid level sensor 44 detects that the liquid level in the cooling tower 40 reaches the preset upper limit value, the first valve 58 can be controlled to close, and the second valve 59 can be controlled to open, so that the condensed water precipitated during the compression process flows to the liquid storage tank 60 after filtering, and is stored in the liquid storage tank 60 as a backup water source.

[0082] By setting up a liquid level sensor 44, the liquid level of the cooling tower 40 is monitored in real time and the opening and closing state of the valve is automatically adjusted, so that precise control and automatic management of the flow of cooling water can be achieved, which helps to improve the overall reliability of the system and can ensure that the cooling tower 40 can obtain sufficient cooling medium at any time, which helps to improve the cooling efficiency and ensure that the energy storage unit can continue to operate efficiently. At the same time, it is also conducive to fully utilizing the cooling water.

[0083] like Figure 1As shown, according to some embodiments of the present application, the energy release unit includes: at least one energy release unit, and the energy release unit includes an expander 21 and a heater 22 connected in sequence.

[0084] Specifically, the energy release unit may include one or more energy release units, each of which includes an expander 21 and a heater 22, and the heater 22 is connected to the expander 21 in sequence (such as through a pipe or a connecting device) to ensure that the air can flow smoothly between the two. In the energy release stage, the air compressed in the energy storage stage can be heated by the heater 22 and expanded by the expander 21, thereby releasing energy and converting it into mechanical energy or electrical energy. Finally, the energy output by the compressed air energy storage system 100 that can recover condensed water can be supplied to the power grid, drive mechanical equipment or be used for other purposes to achieve the reuse of the stored energy.

[0085] It should be pointed out that the heat used by the above-mentioned heater 22 to heat the air can come from the compression heat recovered and stored by the first heat exchanger 12 during the energy storage stage, thereby achieving full utilization of the compression heat and effectively improving the thermal efficiency of the compressed air energy storage system 100 with recoverable condensed water.

[0086] In addition, in some specific embodiments of the present application, the energy storage unit includes two energy storage units connected in series, namely the first energy storage unit and the second energy storage unit, and the first energy storage unit and the second energy storage unit both include a compressor 11, a first heat exchanger 12, a second heat exchanger 13 and a gas-liquid separator 14 connected in series; the energy release unit includes two energy release units connected in series, namely the first energy release unit and the second energy release unit, and the first energy release unit and the second energy release unit both include an expander 21 and a heater 22 connected in series. In the energy storage stage, the air is compressed, heat exchanged, cooled and separated from gas and water twice by the first energy storage unit and the second energy storage unit, so that the gas can reach a higher pressure and store more energy. In the energy release stage, the gas is heated and expanded twice by the first energy release unit and the second energy release unit, so that the expansion process of the gas can release more energy, thereby increasing the energy output in the form of electrical energy or mechanical energy.

[0087] like Figure 1 As shown, according to some embodiments of the present application, the compressed air energy storage system 100 capable of recovering condensed water further includes: a low-temperature heat storage device 70 and a high-temperature heat storage device 80 .

[0088] The low-temperature heat storage device 70 and the high-temperature heat storage device 80 are both connected to the heater 22 and the first heat exchanger 12 .

[0089] Specifically, in the embodiment of the present application, the high-temperature heat storage 80 can be used to store high-temperature heat storage medium, and the low-temperature heat storage 70 can be used to store low-temperature heat storage medium. Both the low-temperature heat storage 70 and the high-temperature heat storage 80 are connected to the heater 22 and the first heat exchanger 12, so that the low-temperature heat storage 70 and the high-temperature heat storage 80 are connected through the first heat exchanger 12 and the heater 22. The high-temperature heat storage 80, the low-temperature heat storage 70, the first heat exchanger 12 and the heater 22 work together to achieve an efficient heat cycle of the compressed air energy storage system 100 with recoverable condensed water. Its working principle is: in the energy storage stage, a large amount of heat is generated during the compressed air process, and the low-temperature heat storage medium in the low-temperature heat storage 70 flows through the first heat exchanger 12 to exchange heat with the air, and becomes a high-temperature heat storage medium and is stored in the high-temperature heat storage 80. In the energy release stage, the high-temperature heat storage medium in the high-temperature heat storage 80 passes through the heater 22 and heats the gas, and at the same time becomes a low-temperature heat storage medium, and flows into the low-temperature heat storage 70 to be used in the next energy storage stage.

[0090] In some specific embodiments of the present application, the heat storage medium material in the high temperature heat storage 80 and the low temperature heat storage 70 is constructed as pressurized water or thermal oil. Pressurized water and thermal oil have the advantages of high heat capacity, good thermal conductivity and relatively low cost. By constructing the heat storage medium material in the high temperature heat storage 80 and the low temperature heat storage 70 as pressurized water or thermal oil, it is beneficial to ensure the stability and effect of storing heat energy in the high temperature heat storage 80 and the low temperature heat storage 70, and save costs, thereby improving the overall performance, safety and economy of the compressed air energy storage system 100 with recoverable condensed water.

[0091] According to the compressed air energy storage system 100 with recyclable condensed water of the present application, the overall working principle is as follows: during the compression process, after the air enters the first compressor 11 and is compressed into high-pressure and high-temperature air, it enters the first first heat exchanger 12 to exchange heat with the low-temperature heat storage medium from the low-temperature heat storage tank, and the high-pressure and high-temperature air is cooled to about 50°C and then cooled by the first second heat exchanger 13, and then separated into dry air and condensed water by the first gas-liquid separator 14. Similarly, the separated high-pressure air is compressed and heat-exchanged by the second compressor 11, the second first heat exchanger 12, and the second second heat exchanger 13 in turn, and the condensed water is precipitated by the second gas-liquid separator 14. That is, the air is compressed, heat-exchanged, cooled, and gas-liquid separated twice before entering the gas storage reservoir 30 for storage. When energy release is required, the dry air enters the first heater 22, the first expander 21, the second heater 22, and the second expander 21 in turn for heating and expansion to generate electricity.

[0092] According to the compressed air energy storage system 100 with recyclable condensed water of the present application, there are three functional paths. The first functional path is the air path, based on the fact that the outside air is compressed by the energy storage unit and then flows into the gas storage reservoir 30 for storage through the gas side pipeline. The gas stored in the gas storage reservoir 30 then flows to the energy release unit through the gas side pipeline to realize the energy storage and energy release of the compressed air energy storage system 100 with recyclable condensed water; the second functional path is the water replenishment path, based on the cooling tower 40 to replenish cooling water to the second heat exchanger 13, and connected with the gas-liquid separator 14 through the return liquid pipeline to recover the condensed water precipitated from the compressed air, and the return liquid The pipeline can be selectively connected to the cooling tower 40 and the liquid storage tank 60 to reasonably distribute the recovered condensed water to the cooling tower 40 for water replenishment or to the liquid storage tank 60 for storage and standby, thereby realizing the full reuse of water resources in the compressed air energy storage system 100 with recoverable condensed water; the third functional path is the heat storage medium path, based on the heat storage medium stored in the high-temperature heat storage device 80 and the low-temperature heat storage device 70, and flowing through the first heat exchanger 12 and the heater 22 according to the different stages of the compressed air energy storage system 100 with recoverable condensed water, thereby realizing the efficient thermal cycle of the compressed air energy storage system 100 with recoverable condensed water.

[0093] like Figure 2 As shown, the water replenishment method of the energy storage system according to the second aspect of the embodiment of the present application is applicable to the energy storage system 100 described in any one of the above embodiments, and the water replenishment method of the energy storage system includes: obtaining the liquid level of the cooling tower 40; when the liquid level reaches a first threshold, opening the first valve 58 and closing the second valve 59 to replenish water to the cooling tower 40; when the liquid level reaches a second threshold, opening the second valve 59 and closing the first valve 58 to supply water to the liquid storage tank 60; wherein the first threshold is lower than the second threshold.

[0094] Specifically, according to the water replenishment method of the energy storage system of the second aspect of the embodiment of the present application, whether the liquid level of the cooling tower 40 reaches the first threshold and the second threshold can be used as a criterion for opening and closing the first valve 58 and the second valve 59, wherein the first threshold is lower than the second threshold, the first threshold can be understood as the preset lower limit of the water amount in the cooling tower 40, and the second threshold can be understood as the preset upper limit of the water amount in the cooling tower 40. When the liquid level reaches the first threshold, it means that the amount of water in the cooling tower 40 is reduced to the preset lower limit, then the first valve 58 is opened, the second valve 59 is closed, the corresponding first branch 54 is connected, and the second branch 55 is closed, the condensed water precipitated from the gas-liquid separator 14 flows into the cooling tower 40 to replenish the water volume of the cooling tower 40, so as to ensure that there is always enough water in the cooling tower 40, thereby ensuring the cooling effect and reliability of the second heat exchanger 13; when the liquid level reaches the second threshold, it means that the amount of water in the cooling tower 40 reaches the preset upper limit, and there is enough water in the cooling tower 40, then the second valve 59 is opened, and the first valve 58 is closed, the corresponding second branch 55 is connected, and the first branch 54 is closed, the condensed water precipitated from the gas-liquid separator 14 flows into the liquid storage tank 60 to be stored and used as a backup water source for the cooling tower 40, thereby achieving multiple guarantees for the water volume of the cooling tower 40 and optimizing the utilization of water resources.

[0095] like Figure 2 As shown, according to some embodiments of the present application, the water replenishment method of the energy storage system also includes: when the liquid level reaches a first threshold, if the energy storage unit stops storing energy, the liquid storage tank 60 replenishes water to the cooling tower 40 until the liquid level reaches a second threshold.

[0096] Specifically, when the obtained liquid level of the cooling tower 40 reaches the first threshold value, the water volume in the cooling tower 40 is reduced to the preset lower limit value. At this time, if the energy storage unit stops storing energy and the gas-liquid separator 14 stops extracting water, although the first valve 58 is opened, the cooling tower 40 cannot continue to obtain water from the first branch 54. The liquid storage tank 60 can replenish water to the cooling tower 40 through the third branch 56 and the third water pump 57 until the liquid level of the cooling tower 40 reaches the second threshold value, the water volume in the cooling tower 40 increases to the preset upper limit value, and the liquid storage tank 60 stops replenishing water. The remaining water source in the liquid storage tank 60 can be used as the next backup water replenishment, thereby realizing the full and effective utilization of water resources in the compressed air energy storage system 100 with recyclable condensed water.

[0097] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0098] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A compressed air energy storage system capable of recovering condensed water, characterized in that: include: An energy storage unit, the energy storage unit comprising: at least one energy storage unit, the energy storage unit comprising a compressor (11), a first heat exchanger (12), a second heat exchanger (13) and a gas-liquid separator (14) which are connected in sequence, the second heat exchanger (13) being configured as a gas-water heat exchanger; Energy release unit; A gas storage reservoir (30), the gas storage reservoir (30) having a gas side pipeline, the gas side pipeline can be selectively connected to the energy storage unit to store energy, or connected to the energy release unit to release energy; A cooling tower (40) and a liquid return pipeline, wherein the cooling tower (40) is connected to the second heat exchanger (13) and supplies cooling water to the second heat exchanger (13); one end of the liquid return pipeline is connected to the gas-liquid separator (14), and the other end is connected to the cooling tower (40) to supply water to the cooling tower (40).

2. The compressed air energy storage system capable of recovering condensed water according to claim 1, characterized in that: The second heat exchanger (13) comprises: a cooling water inlet and a cooling water outlet, the cooling water inlet is connected to the cooling tower outlet via a first pipeline (41), and the cooling water outlet is connected to the cooling tower inlet via a second pipeline (42).

3. The compressed air energy storage system capable of recovering condensed water according to claim 2, characterized in that: The cooling tower (40) is provided with a first water pump (43), which is arranged at the inlet of the cooling tower and / or the outlet of the cooling tower and is suitable for being connected with the first pipeline (41) or the second pipeline (42).

4. The compressed air energy storage system capable of recovering condensed water according to claim 2 or 3, characterized in that: When there are multiple energy storage units, multiple first pipelines (41) are connected in parallel, and multiple second pipelines (42) are connected in parallel.

5. The compressed air energy storage system capable of recovering condensed water according to claim 1, characterized in that: The liquid return pipeline comprises a liquid return pipe (51) and a second water pump (52); the liquid return pipe (51) is in communication with the second water pump (52); and the second water pump (52) is used to replenish water to the cooling tower (40).

6. The compressed air energy storage system capable of recovering condensed water according to claim 5, characterized in that: The liquid return pipe (51) is constructed as an underground pipe.

7. The compressed air energy storage system capable of recovering condensed water according to claim 5, characterized in that: The liquid return pipeline further comprises: a filter (53), wherein the filter (53) is arranged between the liquid return pipe (51) and the cooling tower (40) and is suitable for filtering water returning from the liquid return pipe (51).

8. The compressed air energy storage system capable of recovering condensed water according to claim 7, characterized in that: Also includes: The liquid storage tank (60) further comprises a first branch (54) and a second branch (55), wherein one end of the first branch (54) is connected to the filter (53) and the other end is connected to the cooling tower (40), and one end of the second branch (55) is connected to the filter (53) and the other end is connected to the liquid storage tank (60).

9. The compressed air energy storage system capable of recovering condensed water according to claim 8, characterized in that: The liquid return pipeline also includes: a third branch (56), one end of the third branch (56) is connected to the liquid storage tank (60), and the other end is connected to the cooling tower (40), and the third branch (56) is provided with a third water pump (57) for replenishing water from the liquid storage tank (60) to the cooling tower (40).

10. The compressed air energy storage system capable of recovering condensed water according to claim 8, characterized in that: The first branch (54) is provided with a first valve (58), and the second branch (55) is provided with a second valve (59).

11. The compressed air energy storage system capable of recovering condensed water according to claim 10, characterized in that: The cooling tower (40) is also provided with a liquid level sensor (44), which is electrically connected to the first valve (58) and the second valve (59) and is suitable for controlling the first valve (58) and the second valve (59) to selectively open and close.

12. The compressed air energy storage system capable of recovering condensed water according to claim 1, characterized in that: The energy release unit comprises: at least one energy release unit, and the energy release unit comprises an expander (21) and a heater (22) which are connected in sequence.

13. The compressed air energy storage system capable of recovering condensed water according to claim 12, characterized in that: Also includes: A low-temperature heat storage (70) and a high-temperature heat storage (80), wherein the low-temperature heat storage (70) and the high-temperature heat storage (80) are both connected to the heater (22) and the first heat exchanger (12).

14. A water replenishment method for an energy storage system, applicable to the compressed air energy storage system capable of recovering condensed water according to any one of claims 1 to 13, characterized in that: include: Obtaining the liquid level of the cooling tower (40); When the liquid level reaches a first threshold, the first valve (58) is opened and the second valve (59) is closed to replenish water to the cooling tower (40); When the liquid level reaches a second threshold, the second valve (59) is opened, and the first valve (58) is closed to supply water to the liquid storage tank (60); The first threshold is lower than the second threshold.

15. The water replenishment method for the energy storage system according to claim 14, characterized in that: Also includes: When the liquid level reaches the first threshold, if the energy storage unit stops storing energy, the liquid storage tank (60) replenishes water to the cooling tower (40) until the liquid level reaches the second threshold.

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