Compressed air energy storage and wet cooling tower coupled energy storage and water saving demisting device and method

Abstract

The invention discloses a compressed air energy storage and wet type cooling tower coupled energy storage and water saving demisting device and method. The device comprises a wet type cooling tower; the demisting heat exchanger is mounted at the upper part of the wet cooling tower; the compressed air energy storage system comprises a compressor unit, an expansion unit, a high-pressure air storage tank, a heat storage tank and a cold storage tank; an outlet of the compressor unit is connected with an inlet of the high-pressure gas storage tank, and an outlet of the high-pressure gas storage tank is connected with an inlet of the expansion unit. The heat storage tank is connected with the compressor unit to recover compression heat, and the cold storage tank is connected with the expansion unit to recover expansion cold; the water recovery system comprises a gas-water separator and a water-saving tank; wherein an air outlet of the wet cooling tower is connected with an inlet of the compressor unit; the gas-water separator is connected to a gas flow path between the compressor unit and the high-pressure gas storage tank, and a liquid outlet of the gas-water separator is connected with the water-saving tank; and a heat exchange fluid inlet of the demisting heat exchanger is selectively connected with an outlet of the heat storage tank or an outlet of the cold storage tank. The invention aims to realize low-energy-consumption water saving and demisting of the wet cooling tower while storing energy.

Description

Technical Field

[0001] This invention relates to the technical field of energy storage and industrial water conservation, and in particular to an energy storage, water-saving, and demisting device and method that couples compressed air energy storage with a wet cooling tower. Background Technology

[0002] Compressed air energy storage, as a large-scale physical energy storage technology, has been widely used in grid peak shaving and renewable energy consumption. Meanwhile, industrial wet cooling towers, as core equipment in circulating water systems of industries such as power, chemical, and metallurgy, directly affect the stability and economy of industrial production. Wet cooling towers use direct contact between water and air for heat exchange. During this process, evaporation occurs, cooling the working fluid. This heat exchange mechanism inevitably leads to a significant loss of water through evaporation, resulting in the continuous consumption of valuable freshwater resources. Furthermore, the air discharged from the cooling tower is usually at or near saturation. When this saturated, humid air encounters the relatively cool ambient air, the water vapor rapidly condenses into tiny droplets, appearing as a white plume. This plume phenomenon not only causes visual pollution but can also, in some cases, impact the surrounding microenvironment.

[0003] To address the water consumption problem in cooling towers, existing technologies mainly employ two types of solutions. One type involves installing mechanical water separators inside or at the outlet of the cooling tower to capture adhering water droplets through impact, centrifugation, or other methods. For example, patent application CN113720194A proposes adding a centrifugal fan and condensation pipe at the top of the tower to centrifuge and condense the exhaust gas for recovery; patent application CN222617649U uses a mechanical vibrating filter to achieve gas-water separation. These solutions can recover some liquid water, but their effectiveness in recovering gaseous water is limited, and the mechanical components suffer from wear and maintenance issues over long-term operation. The other type of solution uses active air-to-water extraction technology, extracting moisture from the air through cooling condensation, solid adsorption, or liquid absorption. However, these technologies generally suffer from high energy consumption. Literature research indicates that the unit water production energy consumption of mainstream active air-to-water extraction technologies is approximately 0.38–1.16 kWh / kg, making them economically unfeasible for large-scale industrial applications.

[0004] In cooling tower demisting, common technical approaches include cooling the exhaust air to remove moisture or heating the exhaust air to reduce relative humidity. Both methods require cooling or heating respectively, typically relying on external cold or heat sources, resulting in high energy consumption and system complexity. Some solutions attempt to utilize electric fans or semiconductor cooling, but these essentially still fall into the category of trading energy for environmental benefits.

[0005] On the other hand, research on compressed air energy storage systems mainly focuses on improving system efficiency and comprehensive utilization of thermal energy. During the energy storage (compression) phase, the air compression process generates a large amount of heat of compression; during the energy release (expansion) phase, the air expansion process generates significant cooling. Existing technologies typically balance the heat of compression and cooling within the system to improve the overall energy conversion efficiency of the energy storage system. Summary of the Invention

[0006] To address the problems existing in the prior art, the present invention provides an energy storage, water-saving, and demisting device and method that couples compressed air energy storage with a wet cooling tower. Its purpose is to achieve low-energy consumption, water saving, and demisting of the wet cooling tower while storing energy; and to effectively coordinate the compression heat and expansion cold generated during the operation of the compressed air energy storage system with the needs of the wet cooling tower, thereby coupling the compressed air energy storage system with the wet cooling tower.

[0007] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution: According to a first aspect of the present invention, an energy storage, water-saving, and demisting device coupled with compressed air energy storage and a wet cooling tower is provided, comprising: Wet cooling tower; A demisting heat exchanger is installed on the upper part of the wet cooling tower; A compressed air energy storage system includes a compressor unit, an expander unit, a high-pressure air storage tank, a heat storage tank, and a cold storage tank. The outlet of the compressor unit is connected to the inlet of the high-pressure air storage tank, and the outlet of the high-pressure air storage tank is connected to the inlet of the expander unit. The heat storage tank is connected to the compressor unit to recover compression heat, and the cold storage tank is connected to the expander unit to recover expansion cold. A water recycling system, comprising a gas-water separator and a water-saving tank; The air outlet of the wet cooling tower is connected to the inlet of the compressor unit; The gas-liquid separator is connected to the gas flow path between the compressor unit and the high-pressure gas storage tank, and the liquid outlet of the gas-liquid separator is connected to the water-saving tank. The heat exchange fluid inlet of the demister heat exchanger can be selectively connected to the outlet of the thermal storage tank or the outlet of the cold storage tank.

[0008] In one possible implementation of the first aspect, the compressed air energy storage system further includes multiple compressor-stage post-heat exchangers and an ambient temperature tank; The compressor unit includes a multi-stage compressor, and the outlet of each compressor stage is connected to the air-side inlet of the corresponding heat exchanger after the compressor stage. The air-side outlet of the compressor stage heat exchanger is connected to the inlet of the next stage compressor or the high-pressure gas storage tank. The heat exchange fluid inlet of the compressor stage post-heat exchanger is connected to the ambient temperature tank, and the heat exchange fluid outlet of the compressor stage post-heat exchanger is connected to the heat storage tank.

[0009] In one possible implementation of the first aspect, the gas-water separator is connected between the air-side outlet of the heat exchanger after the compressor stage and the inlet of the next stage compressor.

[0010] In one possible implementation of the first aspect, the compressed air energy storage system further includes multiple expander-stage preheat exchangers, multiple expander-stage postheat exchangers, and an ambient temperature tank; The expander unit includes a multi-stage expander, with the inlet of each expander stage connected to the air-side outlet of the corresponding pre-expander heat exchanger and the outlet of each expander stage connected to the air-side inlet of the corresponding post-expander heat exchanger. The heat exchange fluid inlet of the expander stage preheater is connected to the heat storage tank, and the heat exchange fluid outlet of the expander stage preheater is connected to the ambient temperature tank. The heat exchange fluid inlet of the heat exchanger after the expander stage is connected to the ambient temperature tank, and the heat exchange fluid outlet of the heat exchanger after the expander stage is connected to the cold storage tank.

[0011] In one possible implementation of the first aspect, a valve is provided between the heat exchange fluid inlet of the demister heat exchanger and the outlet of the heat storage tank, and a valve is provided between the heat exchange fluid inlet of the demister heat exchanger and the outlet of the cold storage tank.

[0012] In one possible implementation of the first aspect, the heat exchange fluid outlet of the demister heat exchanger is connected to the inlet of the thermal storage tank or the inlet of the cold storage tank.

[0013] According to a second aspect of the present invention, a method for energy storage, water saving, and demisting based on compressed air energy storage coupled with a wet cooling tower is provided, comprising: Detect the operating status of the compressed air energy storage system; When the compressor unit is in operation, the hot and humid air discharged from the wet cooling tower is introduced into the compressor unit; The introduced hot and humid air is compressed and cooled, causing the water vapor in the air to condense. Condensate is separated by an air-water separator and stored in a water-saving tank, while the separated compressed air is stored in a high-pressure air tank. Recover the heat of compression and store it in a heat storage tank; and When the compressor unit stops working and the wet cooling tower is running, the hot water in the heat storage tank or the cold water in the cold storage tank is passed into the demisting heat exchanger to treat the hot and humid air discharged from the wet cooling tower to eliminate white mist.

[0014] In one possible implementation of the second aspect, the compression and cooling of the introduced hot and humid air includes: The hot, humid air is compressed in multiple stages, and then cooled after each stage of compression.

[0015] In one possible implementation of the second aspect, the hot water in the heat storage tank is passed into a demisting heat exchanger to heat the humid air.

[0016] In one possible implementation of the second aspect, the cold water in the cold storage tank is passed into a demisting heat exchanger to cool the hot and humid air.

[0017] Compared with the prior art, the present invention has at least the following beneficial effects: This invention couples a compressed air energy storage system with a wet cooling tower. The hot, humid air discharged from the wet cooling tower is introduced into the compressor unit. During the staged compression and cooling process, the water vapor in the air reaches saturation and condenses. This condensate is recovered through an air-water separator and stored in a water-saving tank. Compared to conventional active air-to-water extraction technology, the condensation process in this solution is not an additional step for water extraction, but rather a byproduct of the compressed air energy storage system's normal operation during the charging phase. This means that the additional energy consumption for water extraction is only reflected in the small power consumption of auxiliary equipment such as cooling water circulation pumps, far lower than that of mechanical refrigeration water extraction methods. Taking a 1MW cooling tower in a specific embodiment as an example, the unit water production energy consumption during the compression water extraction stage is approximately 0.07 kWh / kg water, significantly lower than the energy consumption level of existing active air-to-water extraction technologies.

[0018] The demisting heat exchanger is installed at the top of the wet cooling tower, and its heat exchange fluid inlet can be selectively connected to the outlet of either the thermal storage tank or the cold storage tank. When the compressor unit stops operating but the cooling tower still needs to work, hot water stored in the thermal storage tank can be introduced into the demisting heat exchanger to heat the humid air discharged from the cooling tower. The relative humidity of the heated air is significantly reduced, and it no longer forms white mist when mixed with ambient air after being discharged from the tower. This heat comes from the heat of compression recovered during the compression process, which was originally a byproduct of the energy storage system, but now it is used for demisting without consuming additional electricity or fuel. Taking heating the humid air to 60°C as an example, effective demisting can be achieved simply by introducing hot water from the thermal storage tank into the demisting heat exchanger, and the operating cost of the entire process is almost zero.

[0019] By monitoring the operating status of the compressed air energy storage system, the system can switch operating modes at different stages. When the compressor unit is operating, the system focuses on recovering moisture and storing heat; when the compressor unit is shut down and the cooling tower is running, the system utilizes the stored heat or cold energy to treat the cooling tower exhaust air. Based on the adaptive switching of operating states, the two types of systems complement each other in the time dimension: the energy storage system's charging phase corresponds to the cooling tower's water production phase, and the energy storage system's quiescent phase corresponds to the cooling tower's demisting phase. The two do not interfere with each other but support each other, simultaneously achieving water conservation and demisting while fulfilling the energy storage peak-shaving function.

[0020] The thermal storage tank is connected to the compressor unit to recover the heat of compression generated during compression; the cold storage tank is connected to the expander unit to recover the cold of expansion generated during expansion. The heat and cold energy, originally balanced within the energy storage system, are demisted in this invention using a demisting heat exchanger for cooling tower demisting. Heating demisting utilizes the heat of compression, while cooling demisting utilizes the cold of expansion, allowing for more efficient utilization of the heat and cold energy generated during the operation of the energy storage system. The cooling demisting mode also recovers additional condensate, further improving the system's water-saving efficiency. The water-saving efficiency is 84.84% when using heating demisting alone, but the overall water-saving efficiency increases to 147% after adding the cooling demisting mode. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the specific embodiments of the present invention, the drawings used in the description of the specific embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of an energy storage, water-saving, and demisting device coupled with a wet cooling tower according to an embodiment of the present invention. Figure 2 In an embodiment of the present invention, a water-saving demisting device coupling compressed air energy storage and a wet cooling tower utilizes the stored hot water for demisting in a sub-circulation. Figure 3 In an embodiment of the present invention, a water-saving demisting device coupling compressed air energy storage and a wet cooling tower utilizes the demisting sub-circulation of stored cold water in the wet cooling tower. Figure 4 The graph shows the variation of water production capacity and energy charging / releasing power of the energy storage water-saving and demisting device coupled with the cooling tower with the air-water ratio, when all the exhaust air from the cooling tower enters the compressed air energy storage system under the condition of fixed heat dissipation capacity (1MW). Figure 5The graph shows the variation of water production capacity and energy charging / releasing power of the energy storage water-saving and demisting device coupled with the compressed air energy storage system, with a fixed wet cooling tower heat dissipation capacity (1MW) and a fixed wet cooling tower water-air ratio of 0.8. The diagram illustrates the variation of the air volume entering the compressed air energy storage system with the energy storage water-saving and demisting device coupled with the wet cooling tower.

[0023] In the diagram: 1. Wet cooling tower; 2. Demisting heat exchanger; 3. High-pressure gas storage tank; 4. Heat storage tank; 5. Cold storage tank; 6. Gas-water separator; 7. Water-saving tank; 8. Heat exchanger after compressor stage; 9. Ambient temperature tank; 10. Compressor; 11. Heat exchanger before expander stage; 12. Heat exchanger after expander stage; 13. Expander; 14. Electric motor; 15. Generator. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] like Figure 1 As shown, the present invention provides an energy storage, water-saving, and demisting device coupled with compressed air energy storage and a wet cooling tower, which mainly includes a wet cooling tower 1, a demisting heat exchanger 2, a compressed air energy storage system, and a water recovery system.

[0026] The wet cooling tower 1 adopts a conventional industrial wet cooling tower structure, which draws in ambient air at the bottom and is equipped with a spray device and heat exchange packing inside. The demister heat exchanger 2 is installed at the upper outlet of the wet cooling tower 1 to perform heat exchange treatment on the exhaust air of the cooling tower.

[0027] The compressed air energy storage system includes a compressor unit, an expander unit, a high-pressure air storage tank 3, a heat storage tank 4, and a cold storage tank 5. The outlet of the compressor unit is connected to the inlet of the high-pressure air storage tank 3 via a pipeline, and the outlet of the high-pressure air storage tank 3 is connected to the inlet of the expander unit via a pipeline. The heat storage tank 4 is connected to the compressor unit to recover the heat generated during compression; the cold storage tank 5 is connected to the expander unit to recover the cold generated during expansion.

[0028] The water recovery system includes a gas-water separator 6 and a water-saving tank 7. The gas-water separator 6 is connected to the gas flow path between the compressor unit and the high-pressure gas storage tank 3, and the liquid outlet of the gas-water separator 6 is connected to the water-saving tank 7 through a pipeline.

[0029] The air outlet of the wet cooling tower 1 is directly connected to the inlet of the compressor unit via a pipeline. The air-water separator 6 is installed in the pipeline between the compressor unit and the high-pressure air storage tank 3. The heat exchange fluid inlet of the demisting heat exchanger 2 is connected to the outlet of the heat storage tank 4 and the outlet of the cold storage tank 5 via pipelines, and can be selectively connected to one of them by switching via valves.

[0030] The working process of this embodiment is as follows: When the compressor unit is running, the hot and humid air discharged from the wet cooling tower 1 is introduced into the compressor unit. Before entering the high-pressure air storage tank 3, the compressed air is separated into condensate by the air-water separator 6, and the condensate is stored in the water-saving tank 7. The separated dry air continues to enter the high-pressure air storage tank 3 for storage. The heat of compression generated during the compression process is recovered through heat exchange and stored in the heat storage tank 4, and the expansion heat generated during the expansion process is recovered and stored in the cold storage tank 5. When the compressor unit stops running but the wet cooling tower 1 still needs to run, the hot water in the heat storage tank 4 or the cold water in the cold storage tank 5 can be introduced into the demisting heat exchanger 2 to treat the hot and humid air discharged from the cooling tower.

[0031] The device described in this embodiment achieves physical coupling between the compressed air energy storage system and the wet cooling tower. By introducing the cooling tower exhaust air into the compressor unit and utilizing the compression process to extract water, low-energy water production is achieved. By connecting the heat storage tank 4 and the cold storage tank 5 to the demisting heat exchanger 2, a heat or cold source with zero marginal cost is provided for demisting the cooling tower.

[0032] In one possible implementation, such as Figure 1 As shown, the compressed air energy storage system also includes multiple compressor-stage post-heat exchangers 8 and an ambient temperature tank 9. The compressor unit consists of multi-stage compressors 10, with the outlet of each compressor 10 connected to the air-side inlet of the corresponding compressor-stage post-heat exchanger 8. The air-side outlet of the compressor-stage post-heat exchanger 8 is connected to the inlet of the next stage compressor 10, and the air-side outlet of the last compressor-stage post-heat exchanger 8 is connected to the high-pressure air storage tank 3. The heat exchange fluid inlet of the compressor-stage post-heat exchanger 8 is connected to the ambient temperature tank 9, and the heat exchange fluid outlet of the compressor-stage post-heat exchanger 8 is connected to the heat storage tank 4.

[0033] In this embodiment, a three-stage compression is used as an example. The outlet of the first-stage compressor 10 is connected to the heat exchanger 8 after the first-stage compressor stage. The air-side outlet of the first-stage compressor stage heat exchanger 8 is connected to the inlet of the second-stage compressor 10. The outlet of the second-stage compressor 10 is connected to the heat exchanger 8 after the second-stage compressor stage, and so on. The heat exchange fluid channels of each compressor stage heat exchanger 8 are connected in parallel or in series to the heat storage tank 4. The specific connection method can be determined according to the actual heat exchange requirements. Water in the ambient temperature tank 9 enters each compressor stage heat exchanger 8 through pipelines, absorbs the heat of compression, and is heated up. After collection, it enters the heat storage tank 4 for storage.

[0034] This embodiment, by setting up multi-stage compression and inter-stage cooling, can ensure that the temperature rise of the air after each stage of compression is not too high, and can adjust the temperature of the hot water stored in the heat storage tank 4 to meet the heating temperature requirements during demisting.

[0035] In one possible implementation, such as Figure 1 As shown, the gas-liquid separator 6 is connected between the air-side outlet of the heat exchanger 8 after the compressor stage and the inlet of the next stage compressor 10. That is, a gas-liquid separator 6 is installed after each stage of compression and cooling.

[0036] Taking a three-stage compression system as an example, driven by the electric motor 14, the air compressed by the first-stage compressor 10 enters the first-stage compressor stage heat exchanger 8 for cooling, and then enters the first-stage air-water separator 6 to separate condensate. The separated dry air then enters the second-stage compressor 10 for further compression. Similarly, after compression and cooling in the second stage, air-water separation occurs again, and after compression and cooling in the third stage, a final air-water separation occurs. The liquid water separated by each stage of the air-water separator 6 enters its corresponding water-saving tank 7 for centralized storage through pipelines.

[0037] This embodiment employs a staged air-water separation method, effectively preventing the moisture separated in the earlier stages from re-evaporating during subsequent compression or impacting the compressor. Staged separation also ensures good dehumidification at each stage, resulting in higher dryness of the air entering the high-pressure air tank 3, which helps protect the tank and expander unit. Furthermore, this arrangement ensures stable quality of the condensate separated at each stage, allowing for direct reuse in cooling tower makeup or other industrial water applications.

[0038] In one possible implementation, such as Figure 1 As shown, the compressed air energy storage system also includes multiple pre-expander stage heat exchangers 11, multiple post-expander stage heat exchangers 12, and an ambient temperature tank 9. The expander unit consists of multi-stage expanders 13. The inlet of each expander 13 is connected to the air-side outlet of the corresponding pre-expander stage heat exchanger 11, and the outlet of each expander 13 is connected to the air-side inlet of the corresponding post-expander stage heat exchanger 12. The heat exchange fluid inlet of the pre-expander stage heat exchanger 11 is connected to the heat storage tank 4, and the heat exchange fluid outlet of the post-expander stage heat exchanger 12 is connected to the ambient temperature tank 9. The heat exchange fluid inlet of the post-expander stage heat exchanger 12 is connected to the ambient temperature tank 9, and the heat exchange fluid outlet of the post-expander stage heat exchanger 12 is connected to the cold storage tank 5.

[0039] This embodiment uses a three-stage expansion as an example. High-pressure air from the high-pressure storage tank 3 first enters the first-stage expander pre-stage heat exchanger 11, where it exchanges heat with hot water from the heat storage tank 4 to increase its temperature. Then, it enters the first-stage expander 13 to expand and perform work. The air exiting the first-stage expander 13 enters the first-stage expander post-stage heat exchanger 12, where it exchanges heat with cold water from the ambient temperature tank 9 to cool down, recovering the expansion coolant. Subsequently, the air enters the second-stage expander pre-stage heat exchanger 11 for reheating, and so on, finally driving the generator 15 to generate electricity. The coolant recovered by each stage of the expander post-stage heat exchanger 12 is carried into the cold storage tank 5 for storage via the heat exchange medium.

[0040] This embodiment, by setting up multi-stage expansion and inter-stage heat exchange, can fully utilize the heat in the heat storage tank 4 to preheat the air before expansion, thereby improving the work capacity of the expander; at the same time, the expansion cold is recovered through the post-stage heat exchanger, storing the cold energy that might otherwise be wasted in the cold storage tank 5. The cold water in the cold storage tank 5 can be used for cooling and dehumidification mode during the demisting process of the cooling tower, realizing the cascade utilization of cold energy.

[0041] In one possible implementation, a valve is installed between the heat exchange fluid inlet of the demister heat exchanger 2 and the outlet of the heat storage tank 4, and a valve is also installed between the heat exchange fluid inlet of the demister heat exchanger 2 and the outlet of the cold storage tank 5. It should be understood that these two valves can be electric or pneumatic valves, and switching control is achieved through a control system.

[0042] In practice, a first valve is installed on the pipeline connecting the outlet of the heat storage tank 4 to the inlet of the demisting heat exchanger 2, and a second valve is installed on the pipeline connecting the outlet of the cold storage tank 5 to the inlet of the demisting heat exchanger 2. When demisting by heating is required, the first valve is opened and the second valve is closed, allowing hot water from the heat storage tank 4 to enter the demisting heat exchanger 2; when demisting by cooling is required, the second valve is opened and the first valve is closed, allowing cold water from the cold storage tank 5 to enter the demisting heat exchanger 2.

[0043] In one possible implementation, such as Figure 2 and Figure 3 As shown, the heat exchange fluid outlet of the demisting heat exchanger 2 is connected to the inlet of the heat storage tank 4 or the inlet of the cold storage tank 5. That is, when hot water is taken from the heat storage tank 4 for heating and demisting, the return water after heat exchange can be returned to the heat storage tank 4; when cold water is taken from the cold storage tank 5 for cooling and demisting, the return water after heat exchange can be returned to the cold storage tank 5.

[0044] Taking the heating mode as an example, the hot water in the heat storage tank 4 enters the demisting heat exchanger 2, and its temperature decreases after exchanging heat with the exhaust air of the cooling tower. The cooled water returns to the inlet of the heat storage tank 4 through the pipeline.

[0045] More preferably, the thermal storage tank 4 is equipped with a stratified water distributor, which allows return water to enter the corresponding temperature layer and maintain the temperature stratification within the thermal storage tank 4.

[0046] Taking the cooling mode as an example, the cold water in the cold storage tank 5 enters the demisting heat exchanger 2, absorbs the heat from the exhaust air, and its temperature rises. The heated water then returns to the inlet of the cold storage tank 5.

[0047] More preferably, the cold storage tank 5 also maintains the temperature distribution inside the tank through a stratified water distributor.

[0048] This embodiment achieves the recycling of heat and cold by connecting the heat exchange fluid outlet of the demister heat exchanger 2 back to the heat storage / cold tank. In heating mode, although the hot water returns to the storage tank after cooling, it still retains a certain temperature and can be used again in subsequent expansion preheating or other heat-using processes. In cooling mode, the cold water returns to the cold storage tank after heating, and its cooling capacity is not completely exhausted, allowing it to be reused in scenarios requiring lower temperature cooling. This arrangement helps improve the overall energy efficiency of the system.

[0049] As another implementation, the heat exchange fluid outlet of the demisting heat exchanger 2 can also be connected to other water interfaces, such as for direct industrial water supply or discharge into the drainage system.

[0050] In one possible implementation, the high-pressure gas storage tank 3 is any one of salt rock caves, hard rock caves, aquifers, abandoned mines, artificial caves, metal gas storage tanks, composite material gas storage tanks, or underwater airbags, and includes a single gas storage device or multiple gas storage devices connected in parallel.

[0051] It should be understood that for large-scale energy storage projects, salt rock caves can be used as gas storage spaces, as these caves have the characteristics of good sealing and large volume; in areas with suitable geological conditions, hard rock caves or aquifer structures can also be used. For small and medium-sized energy storage systems, artificial caves, surface metal gas tanks, composite material gas tanks, or underwater airbags can be used.

[0052] In one possible implementation, the heat exchange medium for the compressor-stage post-heat exchanger 8, the expander-stage pre-heat exchanger 11, and the expander-stage post-heat exchanger 12 is water, mineral oil, or other liquid medium.

[0053] Specifically, when water is used as the heat exchange medium, the system is simpler and less expensive, making it suitable for applications where the heat exchange temperature requirements are not high. When mineral oil is used as the heat exchange medium, it is suitable for heat exchange applications with higher temperatures.

[0054] Indirect heat exchangers can be used at all levels, and their specific type is not limited, as long as they meet the heat exchange requirements.

[0055] This invention provides a method for energy storage, water saving, and demisting by coupling compressed air energy storage with a wet cooling tower based on the device described in any of the above embodiments, specifically including the following steps: Step S1: Detect the operating status of the compressed air energy storage system. The control system monitors the operating status of the compressor unit and expander unit in real time to determine whether the system is currently in the charging (compression) stage, the releasing (expansion) stage, or the stationary stage.

[0056] Step S2: When the compressor unit is in operation, the hot and humid air discharged from the wet cooling tower 1 is introduced into the compressor unit. By switching the pipeline valves, the direct exhaust channel of the cooling tower is closed, and the channel leading to the compressor unit inlet is opened, allowing all or part of the hot and humid air from the cooling tower outlet to enter the compressor unit. The electrical energy consumed by the compressor unit can be provided by off-peak electricity from the power grid, wind power, photovoltaic power, and other renewable energy sources, thereby achieving the storage and efficient utilization of clean energy.

[0057] Step S3: The introduced hot and humid air is compressed and cooled, causing the water vapor in the air to condense. After being compressed by the compressor, the pressure and temperature of the hot and humid air increase. It then enters the heat exchanger for cooling, at which point the water vapor reaches saturation and condenses into liquid water.

[0058] Step S4: The condensate is separated by the air-water separator 6 and stored in the water-saving tank 7, while the separated compressed air is stored in the high-pressure air storage tank 3. The air-water separator 6 captures droplets in the air and discharges them into the water-saving tank 7 through the liquid outlet; the dried compressed air continues to enter the next stage of compression or is directly sent to the high-pressure air storage tank 3.

[0059] Step S5: The heat generated during compression is transferred to the heat exchange medium through the heat exchanger 8. The heated medium is stored in the heat storage tank 4 for use in expansion preheating or demisting heating.

[0060] Step S6: When the compressor unit stops working and the wet cooling tower 1 is running, the hot water in the heat storage tank 4 or the cold water in the cold storage tank 5 is introduced into the demisting heat exchanger 2 to treat the hot and humid air discharged from the wet cooling tower 1 to eliminate white mist. Whether hot or cold water is used depends on the operating conditions and the treatment objective.

[0061] Let's illustrate this with a specific engineering case. A power plant's wet cooling tower has a cooling capacity of 1MW, a cooling water inlet temperature of 37℃, an outlet temperature of 32℃, and an exhaust volume of approximately 38.28kg / s. The matched compressed air energy storage system has a power of approximately 23.87MW (charging) / 14.21MW (releasing), operating under typical daily conditions: 8 hours of charging, 8 hours of rest, and 8 hours of releasing energy.

[0062] In this case, the key design parameters are set as follows: the air-to-water ratio (the ratio of air mass flow rate to cooling water mass flow rate) of wet cooling tower 1 is set to 0.8, and the relative humidity of the inlet air is 60%. The outlet pressure of the third-stage compressor is set to 10 MPa, and the pressure ratios of each stage compressor are equal. The expander unit consists of three stages, with the inlet pressure of the first-stage expander being 4.5 MPa, and the expansion ratios of each stage expander being equal. The atmospheric pressure is 101.3 kPa, the atmospheric temperature is 300 K, and the relative humidity is 0.6. The design calculations neglect the flow pressure loss of air in the heat exchanger and the temperature change of the air in the high-pressure air storage tank 3. The heat exchange between the cooling water and the spray water outside the pipes in wet cooling tower 1 accounts for 80% of the total heat exchange, while the heat exchange with the air outside the pipes accounts for 20% of the total heat exchange.

[0063] During the 8-hour charging phase of the compressor unit, the system saves approximately 0.84 kg / s of water, and the additional power consumption per unit of water produced is approximately 0.07 kWh / kg of water. During the resting period, the heat in the thermal storage tank 4 can be used for heating and demisting. At this time, the energy storage system's cycle efficiency is approximately 59.53%, and the water-saving efficiency (the ratio of the total water produced by the system to the total water evaporated by the wet cooling tower) is approximately 84.84%.

[0064] The method in this embodiment achieves coordinated operation of the compressed air energy storage system and the wet cooling tower by detecting the system status and automatically switching the working mode. During the compression phase, moisture and heat are recovered; during the resting phase, the stored heat or cold energy is used to treat the cooling tower exhaust air. This allows the entire system to simultaneously achieve water conservation and demisting while fulfilling its energy storage and peak-shaving functions, significantly improving energy utilization efficiency.

[0065] In one possible implementation, in step S6, hot water from the heat storage tank 4 is introduced into the demisting heat exchanger 2 to heat the humid air.

[0066] like Figure 2 As shown, in the heating and demisting mode, the saturated humid air discharged from the wet cooling tower 1 flows through the demisting heat exchanger 2 and exchanges heat with the hot water from the heat storage tank 4. The temperature of the hot water entering the demisting heat exchanger 2 depends on the heat grade stored in the heat storage tank 4 and the demisting requirements. For example, the hot water in the heat storage tank 4 heats the saturated humid air, raising its temperature to approximately 333K (60°C), significantly reducing the relative humidity. This heated air, after being discharged from the cooling tower, rapidly mixes and dilutes with the ambient air, resulting in a lower overall relative humidity and eliminating the appearance of white mist.

[0067] After heat exchange, the hot water temperature decreases and can be returned to ambient temperature tank 9 or directly to heat storage tank 4.

[0068] This embodiment uses a heating method for demisting, utilizing the heat recovered during compression. This heat, typically used to preheat compressed air entering the expander in conventional compressed air energy storage systems, is now being used for cooling tower demisting. The operating cost of the heating demisting mode is extremely low, offering significant economic advantages compared to traditional electric or steam heating methods.

[0069] In one possible implementation, in step S6, cold water from the cold storage tank 5 is passed into the demisting heat exchanger 2 to cool the hot and humid air.

[0070] like Figure 3 As shown, in the cooling and demisting mode, the saturated humid air discharged from the wet cooling tower 1 flows through the demisting heat exchanger 2 and exchanges heat with the cold water from the cold storage tank 5. The air is cooled to below the dew point temperature, and the water vapor in it condenses and precipitates out, achieving the dual effects of dehumidification and demisting.

[0071] The above 1MW cooling tower case study is used for calculation and analysis. When operating in cooling and demisting mode, the condensate water intake is approximately 0.62 kg / s. After 8 hours of operation, the water consumption of the wet cooling tower can be reduced from 0.33 kg / s to 0.13 kg / s, a decrease of approximately 62.16%. Considering the water production of the compressor unit (0.84 kg / s × 8 hours), the overall water-saving efficiency of the compressed air coupled wet cooling tower device is increased to approximately 147%. In other words, the water recovered by the system can not only meet the spray water replenishment needs of the wet cooling tower itself, but also provide additional water for external use.

[0072] It should be noted that the cooling demisting mode leads to a decrease in the cycle efficiency of the compressed air energy storage system. In this case, the cycle efficiency of the energy storage system dropped to approximately 45.45% when the cooling demisting mode was used, and the energy consumption per unit of water produced in the condensation demisting stage was relatively high, approximately 1.51 kWh / kg of water. Therefore, in practical applications, the optimal choice between heating and cooling demisting modes should be made by comprehensively considering factors such as water scarcity, electricity prices, and ambient temperature.

[0073] In one possible implementation, in step S3, the hot and humid air is compressed in multiple stages, and cooled after each stage of compression.

[0074] In practice, the compressor unit adopts a three-stage compression configuration. After the first stage compression, the high-temperature and high-pressure air enters the first-stage compressor stage heat exchanger 8 for cooling and condensation. After gas-water separation, it enters the second-stage compressor for further compression. After the second stage compression, it is cooled and separated again. After the third stage compression, it is cooled and separated again, and finally enters the high-pressure air storage tank 3.

[0075] Let's continue with the 1MW cooling tower case study. Through three-stage compression and interstage cooling, the pressure ratio of each compressor stage is equal, and the outlet pressure of the third-stage compressor is set to 10MPa. The cooling effect of the heat exchanger 8 after each compressor stage ensures sufficient condensation of water vapor in the air, increasing water production. Simultaneously, the compression heat recovered by each heat exchanger is stored in the heat storage tank 4 in stages. The heat from the high-temperature stage can be used for expansion preheating, and the heat from the medium- and low-temperature stages can be used for demisting heating, achieving cascaded utilization of heat.

[0076] Figure 4 This graph illustrates the variation of water production capacity and energy charging / releasing power of the energy storage and water-saving demisting device coupled with the cooling tower, assuming a fixed cooling tower heat dissipation capacity (1MW) and all exhaust air from the cooling tower enters the compressed air energy storage system. The graph shows the relationship between the air-to-water ratio of the cooling tower and the available compressed air energy storage coupled with the wet cooling tower. Figure 4 It is evident that, with the heat dissipation capacity of the wet cooling tower remaining constant at 1MW, and under a fixed structural scenario, the heat exchange area of ​​the wet cooling tower is constant. However, as the air-to-water ratio increases (i.e., the processing air volume increases relatively), the required scale (charging / releasing power) of the compressed air energy storage system expands almost linearly. Simultaneously, the system's water production capacity also shows a continuous increasing trend with the expansion of the energy storage system scale. This provides a design basis for customizing compressed air energy storage devices for wet cooling towers of fixed scale under different air-to-water ratios.

[0077] Figure 5 This graph illustrates the variation of water production capacity and energy charging / releasing power of a water-saving and demisting device coupled with the wet cooling tower, assuming a fixed cooling tower heat dissipation capacity (1MW) and a fixed water-to-air ratio of 0.8. A portion of the total exhaust air from the cooling tower enters the compressed air energy storage system. The graph shows the relationship between the air volume entering the compressed air energy storage system and the water-saving and demisting device coupled with the wet cooling tower. Figure 5 It is evident that, with the heat dissipation capacity of the wet cooling tower remaining constant at 1MW and the air-to-water ratio maintained at a fixed 0.8, the required scale (charging / releasing power) of the compressed air energy storage system increases linearly with the increase in the air volume entering the compressed air energy storage system. Similarly, the system's water production capacity also shows a continuous increasing trend with the expansion of the energy storage system's scale.

[0078] Compared to traditional wet cooling tower water-saving and demisting technologies (such as mechanical dehumidifiers and solution dehumidification), this invention achieves significantly lower energy consumption per unit of water produced during the compression water intake stage (approximately 0.07 kWh / kg water) compared to most active air-to-water extraction technologies. The heating and demisting process during the static stage fully utilizes the system's recovered compression waste heat, eliminating the need for additional high-quality energy. It organically integrates multiple functions, including large-scale energy storage, water resource recovery, waste heat / cooling utilization, and visual pollution control, solving the problems of traditional technologies such as limited functionality, high energy consumption, and potential secondary pollution.

[0079] The energy storage system can still store energy by compressing air during off-peak hours and release that energy to generate electricity during peak hours. The introduction of cooling tower exhaust does not affect the main function of the compressed air energy storage system; it merely adds the value of moisture recovery and energy storage during operation. This allows the device of this invention to provide water-saving and demisting benefits while still possessing the core capability of large-scale energy storage.

[0080] In the description of this invention, it should be understood that the terms "upper", "lower", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0081] In this invention, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0082] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0083] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0084] Finally, it should be noted that the above-described embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit them. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the scope of the technology disclosed in the present invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered within the scope of protection of the present invention.

Claims

1. A water-saving and demisting energy storage device coupled with compressed air energy storage and a wet cooling tower, characterized in that, include: Wet cooling tower (1); Demisting heat exchanger (2), which is installed on the upper part of the wet cooling tower (1); A compressed air energy storage system includes a compressor unit, an expander unit, a high-pressure air storage tank (3), a heat storage tank (4), and a cold storage tank (5); the outlet of the compressor unit is connected to the inlet of the high-pressure air storage tank (3), and the outlet of the high-pressure air storage tank (3) is connected to the inlet of the expander unit; the heat storage tank (4) is connected to the compressor unit to recover compression heat, and the cold storage tank (5) is connected to the expander unit to recover expansion cold; A water recycling system, the water recycling system comprising a gas-water separator (6) and a water-saving tank (7); The air outlet of the wet cooling tower (1) is connected to the inlet of the compressor unit; The gas-water separator (6) is connected to the gas flow path between the compressor unit and the high-pressure gas storage tank (3), and the liquid outlet of the gas-water separator (6) is connected to the water-saving tank (7). The heat exchange fluid inlet of the demisting heat exchanger (2) may be selectively connected to the outlet of the heat storage tank (4) or the outlet of the cold storage tank (5).

2. The energy storage, water-saving, and demisting device coupled with compressed air energy storage and a wet cooling tower according to claim 1, characterized in that, The compressed air energy storage system also includes multiple compressor-stage post-heat exchangers (8) and an ambient temperature tank (9). The compressor unit includes a multi-stage compressor (10), and the outlet of each stage compressor (10) is connected to the air-side inlet of the corresponding compressor stage heat exchanger (8). The air-side outlet of the compressor stage heat exchanger (8) is connected to the inlet of the next stage compressor (10) or the high-pressure gas storage tank (3). The heat exchange fluid inlet of the compressor stage post-heat exchanger (8) is connected to the ambient temperature tank (9), and the heat exchange fluid outlet of the compressor stage post-heat exchanger (8) is connected to the heat storage tank (4).

3. The energy storage, water-saving, and demisting device coupled with compressed air energy storage and a wet cooling tower according to claim 2, characterized in that, The gas-water separator (6) is connected between the air-side outlet of the heat exchanger (8) after the compressor stage and the inlet of the next stage compressor (10).

4. The energy storage, water-saving, and demisting device coupled with compressed air energy storage and a wet cooling tower according to claim 1, characterized in that, The compressed air energy storage system also includes multiple expander-stage preheater heat exchangers (11), multiple expander-stage postheater heat exchangers (12), and an ambient temperature tank (9). The expander unit includes a multi-stage expander (13), the inlet of each expander (13) is connected to the air-side outlet of the corresponding expander stage preheater (11), and the outlet of each expander (13) is connected to the air-side inlet of the corresponding expander stage postheater (12). The heat exchange fluid inlet of the expander stage preheater (11) is connected to the heat storage tank (4), and the heat exchange fluid outlet of the expander stage preheater (11) is connected to the ambient temperature tank (9). The heat exchange fluid inlet of the expander stage heat exchanger (12) is connected to the ambient temperature tank (9), and the heat exchange fluid outlet of the expander stage heat exchanger (12) is connected to the cold storage tank (5).

5. The energy storage, water-saving, and demisting device coupled with compressed air energy storage and a wet cooling tower according to claim 1, characterized in that, A valve is provided between the heat exchange fluid inlet of the demister heat exchanger (2) and the outlet of the heat storage tank (4), and a valve is provided between the heat exchange fluid inlet of the demister heat exchanger (2) and the outlet of the cold storage tank (5).

6. The energy storage, water-saving, and demisting device coupled with compressed air energy storage and a wet cooling tower according to claim 1, characterized in that, The heat exchange fluid outlet of the demisting heat exchanger (2) is connected to the inlet of the heat storage tank (4) or the inlet of the cold storage tank (5).

7. A method for energy storage, water saving, and demisting based on compressed air energy storage coupled with a wet cooling tower according to any one of claims 1 to 6, characterized in that, include: Detect the operating status of the compressed air energy storage system; When the compressor unit is in operation, the hot and humid air discharged from the wet cooling tower (1) is introduced into the compressor unit; The introduced hot and humid air is compressed and cooled, causing the water vapor in the air to condense. Condensate is separated by a gas-water separator (6) and stored in a water-saving tank (7), while the separated compressed air is stored in a high-pressure air tank (3). The heat of compression is recovered and stored in a heat storage tank (4); and When the compressor unit stops working and the wet cooling tower (1) is running, the hot water in the heat storage tank (4) or the cold water in the cold storage tank (5) is introduced into the demisting heat exchanger (2) to treat the hot and humid air discharged from the wet cooling tower (1) to eliminate white mist.

8. The energy storage, water-saving, and demisting method coupled with compressed air energy storage and a wet cooling tower according to claim 7, characterized in that, The compression and cooling of the introduced hot and humid air includes: The hot, humid air is compressed in multiple stages, and then cooled after each stage of compression.

9. The energy storage, water-saving, and demisting method according to claim 7, characterized in that, Hot water in the heat storage tank (4) is passed into the demisting heat exchanger (2) to heat the humid air.

10. The energy storage, water-saving, and demisting method according to claim 7, characterized in that, The cold water in the cold storage tank (5) is passed into the demisting heat exchanger (2) to cool the hot and humid air.

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