A near-isothermal gas compression device and compression system using the same

Abstract

The application discloses a near-isothermal compression device and a compression system using the same. The near-isothermal compression device comprises a compression cylinder, an air-water separator, and a water supplement tank. The compression cylinder is connected with a low-pressure gas storage tank through an air inlet. The air-water separator is connected with the compression cylinder through an air outlet of the compression cylinder, and is used for separating air and water of the compression cylinder. The air-water separator is connected with a high-pressure gas storage through an air outlet. The water supplement tank is connected with the air outlet of the compression cylinder, and is connected with the air-water separator through a water inlet. A radiator is connected with the water outlet of the compression cylinder and the water outlet of the water supplement tank through inlets, and is used for radiating water in the radiator. The near-isothermal compression device ensures that the last stage of the compression process is close to a near-isothermal process. The compression system has less heat surplus and total power consumption, and the compression power consumption is significantly reduced, so that the overall efficiency of the system is further improved.

Description

Technical Field

[0001] This application relates to the field of compressed air energy storage technology, and in particular to a near-isothermal air compressor and a compression system using the same. Background Technology

[0002] Compressed air energy storage is a large-scale energy storage technology that converts electrical energy into air pressure potential energy and thermal energy of a heat storage medium for storage, and then converts it back into electrical energy during peak electricity demand periods. It mainly consists of a compression energy storage process and an expansion energy release process. The compression energy storage process mainly utilizes excess electrical energy from the power grid, compresses air using a compressor to store electrical energy, and then transports the compressed air to rock caves, abandoned salt caves, abandoned mines, or other pressure vessels.

[0003] In thermodynamics, compression processes are classified into adiabatic, isothermal, and polytropic processes. In adiabatic compression, the gas is compressed without the addition of external heat or the release of internal heat, and the work consumed in adiabatic compression is the greatest. In isothermal compression, the gas is compressed while exchanging heat with the surroundings to maintain a constant temperature, and the work consumed is the least, but this is difficult to achieve. Polytropic processes are a state change process that a real gas undergoes. It is neither completely adiabatic nor completely isothermal, but rather a state change process in between. It allows the system to exchange some heat with the surroundings, and its work consumption is between that of adiabatic and isothermal processes. It is currently the most widely used compression method.

[0004] Currently, the compression process of compressed air energy storage systems faces the following problems in practical applications: 1) The traditional compression process generates a lot of excess heat, resulting in serious energy waste; 2) The compression power consumption is relatively high, which affects the overall electrical efficiency of the system; 3) The pressure change range of the final compression process is narrow, the required gas storage volume is large, the energy storage density is low, and the construction cost of the gas storage is high. Summary of the Invention

[0005] The purpose of this application is to provide a near-isothermal compressed gas device, including: The air cylinder has its air inlet connected to a low-pressure air tank. A gas-water separator, the air inlet of which is connected to the exhaust port of the compressor cylinder, is used to separate the gas and water in the gas discharged from the compressor cylinder. The exhaust port of the gas-water separator is connected to a high-pressure gas storage tank. A water supply tank is connected to the exhaust port of the compressed air cylinder, and the water inlet of the water supply tank is connected to the drain port of the air-water separator. The radiator has its inlet connected to the drain outlet of the air compressor and the drain outlet of the water tank, respectively, for dissipating heat from the water entering the radiator. The water injection piston has its inlet connected to the outlet of the radiator, and its outlet connected to the inlet of the air compressor. The water injection piston draws water to reduce the pressure inside the compressed air cylinder, allowing gas from the low-pressure gas storage tank to be injected into the compressed air cylinder. The water injection piston pressurizes the low-pressure gas in the compressed air cylinder, and the injected water absorbs the heat generated by compression, so that the compressed air is sent to the high-pressure gas storage tank through the gas-water separator.

[0006] As an optional embodiment, a first shut-off valve is provided between the low-pressure gas storage tank and the air inlet of the pressure cylinder, the air outlet of the pressure cylinder is connected to one end of a second shut-off valve, and the other end of the second shut-off valve is connected to the gas-water separator and the water replenishment tank respectively.

[0007] As an optional embodiment, a check valve is provided between the gas-water separator and the high-pressure gas storage tank.

[0008] As an optional embodiment, a sixth shut-off valve is provided between the drain outlet of the gas-water separator and the inlet of the water supply tank, and a third shut-off valve is provided between the outlet of the water supply tank and the inlet of the radiator.

[0009] As an optional embodiment, one end of the water injection piston is provided with a driving structure, a fourth shut-off valve is provided between the drain port of the water injection piston and the water inlet of the air compressor, and a nozzle communicating with the fourth shut-off valve is provided inside the air compressor, the nozzle being used to atomize the cold water entering the air compressor.

[0010] As an optional embodiment, a fifth shut-off valve is provided between the outlet of the radiator and the inlet of the water injection piston.

[0011] The purpose of this application embodiment is also to provide a near-isothermal compression system, including the aforementioned near-isothermal compressor device, and further including: A multi-stage compressor, each stage connected to a corresponding electric motor; A multi-stage heat exchanger is provided between two adjacent compressors; A multi-stage air separator, which is connected to the outlet of the corresponding heat exchanger; The low-pressure gas storage tank has its inlet connected to the final stage air separator and its outlet connected to the inlet of the near-isothermal compressor. The high-pressure gas storage tank has its inlet connected to the outlet of the near-isothermal gas compressor.

[0012] As an optional embodiment, the near-isothermal compression system further includes: A cold water tank is connected to the inlet of the multi-stage heat exchangers via a cold water pump. The high-temperature water tank is connected to the drain outlet of each of the multiple heat exchangers.

[0013] The beneficial effects of the embodiments of this application are as follows: The structural design of this application is reasonable. The near-isothermal compressor device ensures that the final compression process is close to a near-isothermal process. The compression system has little heat surplus and low total power consumption, which significantly reduces compression power consumption and further improves the overall system efficiency.

[0014] The compression system of this application adopts a constant-variable separation scheme, with the pressure ratio of the first-stage and second-stage compressors remaining constant, ensuring that the first two compressors are always operating at high efficiency. This compression system has a wide pressure ratio variation range, compared to the narrow pressure ratio variation of traditional compressors, enabling it to adapt to significant pressure fluctuations in the gas storage facility.

[0015] The compression system described in this application adapts to significant pressure fluctuations, reducing the required gas storage capacity. Throughout the compression process, as the gas storage pressure gradually increases, the final compression system continuously pumps air into the storage facility, maintaining stable operation. Furthermore, it increases energy storage density, reduces storage capacity and construction costs, significantly lowering the overall cost of gas storage facility construction. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the near-isothermal gas compressor device according to an embodiment of this application; Figure 2 This is a schematic diagram of the near-isothermal compression system according to an embodiment of this application.

[0017] in, 1. Primary compressor; 2. Secondary compressor; 3. Low-pressure air tank; 4. High-pressure air storage tank; 5. Primary heat exchanger; 6. Secondary heat exchanger; 7. Primary air separator; 8. Secondary air separator; 9. Near-isothermal air compressor; 10. High-temperature water tank; 11. Cold water tank; 12. Cold water pump; 13. Air compressor cylinder; 14. Water injection piston; 15. Air-water separator; 16. Make-up water tank; 17. Radiator; 18. First shut-off valve; 19. Second shut-off valve; 20. Third shut-off valve; 21. Sixth shut-off valve; 22. Fourth shut-off valve; 23. Fifth shut-off valve; 24. Crankshaft; 25. Nozzle; 26. Check valve. Detailed Implementation

[0018] Various embodiments and features of this application are described herein with reference to the accompanying drawings.

[0019] It should be understood that various modifications can be made to the embodiments described herein. Therefore, the above description should not be considered as limiting, but merely as an example of embodiments. Other modifications within the scope and spirit of this application will be apparent to those skilled in the art.

[0020] The accompanying drawings, which are included in and form part of this specification, illustrate embodiments of the present application and, together with the general description of the present application given above and the detailed description of the embodiments given below, serve to explain the principles of the present application.

[0021] These and other features of this application will become apparent from the following description of preferred forms of embodiments given as non-limiting examples, with reference to the accompanying drawings.

[0022] It should also be understood that although this application has been described with reference to some specific examples, those skilled in the art can certainly implement many other equivalent forms of this application.

[0023] The above and other aspects, features and advantages of this application will become more apparent when taken in conjunction with the accompanying drawings and in view of the following detailed description.

[0024] Specific embodiments of this application are described thereafter with reference to the accompanying drawings; however, it should be understood that the claimed embodiments are merely examples of this application, which can be implemented in various ways. Well-known and / or repeated functions and structures are not described in detail to avoid unnecessary or redundant details that could obscure the application. Therefore, the specific structural and functional details claimed herein are not intended to be limiting, but merely serve as the basis and representative basis for the claims to teach those skilled in the art to use this application in a variety of substantially any suitable detailed structures.

[0025] This specification may use the phrases “in one embodiment,” “in another embodiment,” “in yet another embodiment,” or “in other embodiments,” all of which may refer to one or more of the same or different embodiments according to this application.

[0026] An embodiment of this application provides a near-isothermal gas compressor, such as... Figure 1 As shown, it includes a compressor cylinder 13, an air-water separator 15, a water tank 16, a radiator 17, and a water injection piston 14. The near-isothermal compressor 9 can adapt to large fluctuations in exhaust pressure, with an exhaust pressure fluctuation range of 4 MPa to 13 MPa.

[0027] The air inlet of the compressor cylinder 13 is connected to the low-pressure gas storage tank 3. The compressor cylinder 13 is a component used to compress gas, and its air inlet is connected to the low-pressure gas storage tank 3 to receive low-pressure gas and compress it.

[0028] The air inlet of the gas-water separator 15 is connected to the exhaust port of the compressor cylinder 13, and is used to separate the gas and water in the gas discharged from the compressor cylinder 13. The exhaust port of the gas-water separator 15 is connected to the high-pressure gas storage tank 4. The gas-water separator 15 is a device that separates the water and gas in the gas discharged from the compressor cylinder 13. The separated gas enters the high-pressure gas storage tank 4, and the separated water is further processed.

[0029] The water supply tank 16 is connected to the exhaust port of the air compressor 13, and the water inlet of the water supply tank 16 is connected to the drain port of the air-water separator 15. The water supply tank 16 is a container for storing water, connected to the exhaust port of the air compressor 13, and receives water discharged from the air-water separator 15 to replenish the water in the device.

[0030] The inlet of the radiator 17 is connected to the drain outlet of the air compressor 13 and the drain outlet of the water tank 16, respectively, for dissipating heat from the water entering the radiator 17. The radiator 17 is a device for dissipating heat from the water entering it, reducing the water temperature for recycling.

[0031] The inlet of the water-injecting piston 14 is connected to the outlet of the radiator 17, and the outlet of the water-injecting piston 14 is connected to the inlet of the air compressor 13. The water-injecting piston 14 is a component that realizes the intake and compression of gas in the air compressor 13 through water intake and water injection operations.

[0032] The water injection piston 14 draws water to reduce the pressure inside the compression cylinder 13, so that the gas in the low-pressure gas storage tank 3 is injected into the compression cylinder 13. The water injection piston 14 injects water to pressurize the low-pressure gas in the compression cylinder 13, and the injected water can absorb the heat generated by compression, so that the compressed air is sent into the high-pressure gas storage tank 4 through the gas-water separator 15.

[0033] In this embodiment, the near-isothermal gas compression device 9 is a device that enables the gas compression process to be close to an isothermal state (i.e., with small temperature changes). Through a special structure and working method, it reduces the large temperature rise caused by the heat generated during gas compression.

[0034] In this application, when the water injection piston 14 draws in water, a low pressure is formed in the compression cylinder 13. Gas from the low-pressure storage tank 3 is injected into the compression cylinder 13 under the pressure difference. Then, water is injected by the water injection piston 14, pressurizing the low-pressure gas in the compression cylinder 13. The injected water absorbs the heat generated by compression. The compressed air, containing moisture, enters the air-water separator 15 for air-water separation. The separated gas enters the high-pressure storage tank 4, and the separated water enters the water replenishment tank 16. Excess water in the compression cylinder 13 also enters the water replenishment tank 16 directly through a bypass pipe. During the next water injection piston 14 draws in water, the water in the water replenishment tank 16 enters the radiator 17 for cooling through the drain port of the water replenishment tank 16. The cooled water then returns to the compression cylinder 13 through the water injection piston 14.

[0035] Specifically, in some industrial scenarios that require high-pressure compressed air, such as mining and the operation of pneumatic equipment in large factories, the near-isothermal air compressor 9 is used to compress the low-pressure air collected from the low-pressure air storage tank 3 to provide high-pressure air that meets the requirements.

[0036] This application achieves near-isothermal compression, reducing the temperature rise caused by compression, improving compression efficiency, and reducing energy consumption; air-water separation and water recycling save water resources, while ensuring the quality of compressed air and meeting the safe and reliable operation conditions of the equipment.

[0037] In one embodiment, such as Figure 1 As shown, a first shut-off valve 18 is provided between the low-pressure gas storage tank 3 and the air inlet of the air compressor 13. The air outlet of the air compressor 13 is connected to one end of a second shut-off valve 19. The other end of the second shut-off valve 19 is connected to the gas-water separator 15 and the water replenishment tank 16, respectively.

[0038] In this embodiment, the first shut-off valve 18 is a valve installed between the low-pressure gas storage tank 3 and the air inlet of the compressor cylinder 13, used to control the gas supply from the low-pressure gas storage tank 3 to the compressor cylinder 13, and can be opened or closed.

[0039] The second shut-off valve 19 is a valve that connects one end to the air outlet of the compressor cylinder 13 and the other end to the air-water separator 15 and the water supply tank 16. It is used to control the gas from the compressor cylinder 13 to enter the air-water separator 15 and the excess water to enter the water supply tank 16.

[0040] In this application, by controlling the opening and closing of the first shut-off valve 18, the low-pressure gas storage tank 3 can be controlled to supply gas to the compressor cylinder 13; by controlling the second shut-off valve 19, the gas from the compressor cylinder 13 can be controlled to enter the gas-water separator 15 and the excess water can enter the water replenishment tank 16.

[0041] This application facilitates flexible control over the gas supply and discharge direction of the compressor cylinder 13, improving the ease of operation and reliability of the device.

[0042] In one embodiment, such as Figure 1 As shown, a check valve 26 is provided between the gas-water separator 15 and the high-pressure gas storage tank 4.

[0043] In this embodiment, the check valve 26 is a valve installed between the gas-water separator 15 and the high-pressure gas storage tank 4, which only allows gas to flow from the gas-water separator 15 to the high-pressure gas storage tank 4, preventing gas in the high-pressure gas storage tank 4 from flowing back to the gas-water separator 15.

[0044] When this application is used, the gas separated by the gas-water separator 15 enters the high-pressure gas storage tank 4 through the check valve 26 under pressure. Due to the one-way conduction characteristic of the check valve 26, the gas in the high-pressure gas storage tank 4 will not flow back to the gas-water separator 15.

[0045] Specifically, when the pressure fluctuates within the high-pressure gas storage tank 4, the check valve 26 effectively prevents gas backflow, ensuring the normal operation of the gas-water separator 15 and the correct gas flow direction. This application prevents gas backflow, protects the gas-water separator 15 and other components, and ensures stable system operation.

[0046] In one embodiment, such as Figure 1 As shown, a sixth shut-off valve 21 is provided between the drain outlet of the gas-water separator 15 and the inlet of the water supply tank 16, and a third shut-off valve 20 is provided between the outlet of the water supply tank 16 and the inlet of the radiator 17.

[0047] In this embodiment, the sixth shut-off valve 21 is a valve installed between the drain outlet of the gas-water separator 15 and the inlet of the water supply tank 16, used to control the water discharged from the gas-water separator 15 to enter the water supply tank 16.

[0048] The third shut-off valve 20 is a valve installed between the outlet of the water supply tank 16 and the inlet of the radiator 17, used to control the water in the water supply tank 16 to enter the radiator 17.

[0049] In this application, by controlling the opening and closing of the sixth shut-off valve 21, it is possible to control whether the water discharged from the air-water separator 15 enters the water supply tank 16; by controlling the third shut-off valve 20, it is possible to control whether the water in the water supply tank 16 enters the radiator 17 for heat dissipation.

[0050] Specifically, when the water injection piston 14 draws in water, the sixth shut-off valve 21 can be opened to allow water in the air-water separator 15 to flow into the water supply tank 16, and the third shut-off valve 20 can be opened to allow water in the water supply tank 16 to enter the radiator 17. When the water injection piston 14 injects water, the sixth shut-off valve 21 and the third shut-off valve 20 can be closed to prevent backflow. This application facilitates the control of water flow direction and volume, enabling the rational utilization and circulation of water.

[0051] In one embodiment, such as Figure 1 As shown, one end of the water injection piston 14 is provided with a driving structure, and a fourth shut-off valve 22 is provided between the drain port of the water injection piston 14 and the water inlet of the air compressor 13. The air compressor 13 is provided with a nozzle 25 that communicates with the fourth shut-off valve 22. The nozzle 25 is used to atomize the cold water entering the air compressor 13.

[0052] In this embodiment, a drive structure is installed at one end of the water injection piston 14 and is used to drive the water injection piston 14 to perform water intake and water injection operations. For example, it is driven by electric, hydraulic or pneumatic methods.

[0053] Specifically, the water injection piston 14 is fixed on the crankshaft 24 and, driven by the drive device, can perform reciprocating motion in the horizontal direction. When moving horizontally to the left, it injects water, and when moving horizontally to the right, it pumps water. The volume of the water injection piston 14 is slightly larger than the volume of the air pressure cylinder 13 by 1% to 5%, ensuring that the air in the air pressure cylinder 13 can be completely discharged.

[0054] The fourth shut-off valve 22 is a valve installed between the drain port of the water injection piston 14 and the inlet of the air compressor 13, used to control the water injection operation of the water injection piston 14 into the air compressor 13.

[0055] The nozzle 25 is installed inside the compressor cylinder 13 and communicates with the fourth shut-off valve 22. It is used to atomize the cold water entering the compressor cylinder 13, so that it can fully exchange heat with the compressed air, making the compression process in the cylinder tend to be a near-isothermal process, and minimizing the power consumption of compression.

[0056] When this application is used, the drive structure drives the water injection piston 14 to perform water intake and water injection operations. When water is drawn in, a low-pressure intake gas is formed in the pressure cylinder 13. When water is injected, water is injected into the pressure cylinder 13 through the fourth shut-off valve 22. After the water is atomized through the nozzle 25, it comes into full contact with the gas and absorbs the heat generated by compression, thus ensuring the effect of near-isothermal compression.

[0057] This application atomizes water through nozzle 25, which improves the efficiency of water heat absorption and further ensures the effect of near-isothermal compression. At the same time, the setting of the drive structure and the shut-off valve facilitates precise control of the water injection operation.

[0058] In one embodiment, such as Figure 1 As shown, a fifth shut-off valve 23 is provided between the outlet of the radiator 17 and the inlet of the water injection piston 14.

[0059] In this embodiment, the fifth shut-off valve 23 is a valve installed between the outlet of the radiator 17 and the inlet of the water injection piston 14, used to control the water after the radiator 17 dissipates heat to enter the water injection piston 14.

[0060] In this application, by controlling the opening and closing of the fifth shut-off valve 23, it is possible to control whether the water after the radiator 17 has dissipated heat enters the water injection piston 14, thereby controlling the water circulation.

[0061] Specifically, when the water injection piston 14 injects water into the pressure cylinder 13, the fifth shut-off valve 23 can be closed to prevent water from entering the water injection piston 14; when the water injection piston 14 draws water, the fifth shut-off valve 23 is opened to allow the cooled water to enter the water injection piston 14 for circulation. This application facilitates the control of water circulation, improving the operational convenience and reliability of the system.

[0062] In summary, the working process of the near-isothermal gas compressor 9 of this application includes a gas injection process and a gas compression process, which are carried out alternately. The gas injection process of the gas cylinder 13 is as follows: First, operate the valves: open the first stop valve 18, the fifth stop valve 23, the third stop valve 20, and the sixth stop valve 21, and close the second stop valve 19 and the fourth stop valve 22.

[0063] Next, the water injection piston 14 begins to move, and the piston rod of the water injection piston 14 moves horizontally to the right under the drive of the crankshaft 24. During this process, water from the air separator 15 enters the water supply tank 16, and the water in the water supply tank 16 is drawn into the radiator 17, where it needs to be cooled down before entering the water injection piston 14.

[0064] At this time, because the water in the pressure cylinder 13 is sucked away by the water injection piston 14, a low-pressure area is formed inside the cylinder. The air pressure in the low-pressure storage tank 3 is higher than the pressure in the pressure cylinder 13. Since the first shut-off valve 18 connects the low-pressure storage tank 3 and the pressure cylinder 13, the gas in the low-pressure storage tank 3 will be injected into the pressure cylinder 13.

[0065] When the piston rod of the water injection piston 14 moves horizontally to the rightmost end, the air in the air cylinder 13 is filled. At this time, the air injection in the air cylinder 13 ends, and the previously opened first shut-off valve 18, fifth shut-off valve 23, third shut-off valve 20 and sixth shut-off valve 21 are closed.

[0066] The air compression process of the air compressor 13 is as follows: First, operate the valves: open the second stop valve 19 and the fourth stop valve 22, and close the first stop valve 18, the fifth stop valve 23, the third stop valve 20, and the sixth stop valve 21.

[0067] Next, the water injection piston 14 begins to move. Driven by the crankshaft 24, the piston rod of the water injection piston 14 moves to the left, forcing the cold water in the water injection piston 14 into the pressure cylinder 13.

[0068] At this time, cold water enters the compressor cylinder 13 and is atomized and sprayed through the nozzle 25. The water falls evenly from the top of the compressor cylinder 13 to the bottom. The water pressurizes the air inside the compressor cylinder 13 and absorbs the heat generated by compression, making the entire compression process nearly isothermal.

[0069] When the air pressure in the compressor cylinder 13 is higher than the pressure in the high-pressure air storage tank 4, the air in the compressor cylinder 13 will enter the high-pressure air storage tank 4 through the air-water separator 15 and the check valve 26 in sequence.

[0070] When the piston rod of the water injection piston 14 reaches the leftmost end, the water in the water injection piston 14 is just completely drained, the water in the air compressor cylinder 13 is full, and the excess water directly enters the water supply tank 16 through the bypass pipe. At this time, the air compressor cylinder 13 finishes compressing, and the previously opened second shut-off valve 19 and fourth shut-off valve 22 are closed.

[0071] With the rapid rotation of crankshaft 24, the air in low-pressure gas tank 3 is continuously compressed into high-pressure gas storage tank 4 through compressor cylinder 13, completing the continuous compression process of gas.

[0072] An embodiment of this application provides a near-isothermal compression system, such as... Figure 2 As shown, the device includes the aforementioned near-isothermal compressor 9, as well as a multi-stage compressor, a multi-stage heat exchanger, a multi-stage air separator, a low-pressure gas storage tank 3, and a high-pressure gas storage chamber 4.

[0073] The multi-stage compressors are each connected to their corresponding electric motors. The multi-stage heat exchangers are each located between two adjacent compressors. The multi-stage air separator is connected to the outlet of its corresponding heat exchanger. The inlet of the low-pressure gas storage tank 3 is connected to the final stage air separator, and its outlet is connected to the inlet of the near-isothermal compressor 9. The inlet of the high-pressure gas storage tank 4 is connected to the outlet of the near-isothermal compressor 9.

[0074] In this embodiment, the multi-stage compressor consists of multiple compressors connected in sequence. Each compressor gradually increases the gas pressure and is connected to a corresponding electric motor, which drives the compression operation.

[0075] A multistage heat exchanger consists of multiple heat exchangers connected in sequence. Any heat exchanger is installed between two adjacent compressors to cool the compressed gas and reduce its temperature.

[0076] A multi-stage air separator consists of multiple air separators connected in sequence. Each air separator is connected to the outlet of a corresponding heat exchanger and is used to separate moisture and impurities from the cooled gas.

[0077] The low-pressure gas storage tank 3 is a container for storing low-pressure gas after multi-stage compression and processing. Its inlet is connected to the final air separator, and its outlet is connected to the inlet of the near-isothermal gas compressor 9.

[0078] The high-pressure gas storage tank 4 is a container for storing high-pressure gas after being compressed by the near-isothermal gas compressor 9, and its inlet is connected to the outlet of the near-isothermal gas compressor 9.

[0079] In application, this application uses a multi-stage compressor to progressively compress air in a large-scale air compression and storage system. After being cooled by a multi-stage heat exchanger and separated by a multi-stage air separator, the low-pressure air is stored in a low-pressure storage tank 3 and then compressed into a high-pressure storage tank 4 by a near-isothermal compressor 9 for subsequent use.

[0080] This application improves compression efficiency and reduces compression power consumption through multi-stage compression, cooling and separation. The near-isothermal compressor 9 further ensures the isothermal nature of the compression process, improving the performance and reliability of the entire system.

[0081] In one embodiment, such as Figure 2 As shown, the near-isothermal compression system further includes a cold water tank 11 and a high-temperature water tank 10. The cold water tank 11 is connected to the inlet of the multi-stage heat exchanger via a cold water pump 12. The high-temperature water tank 10 is connected to the outlet of the multi-stage heat exchanger.

[0082] The cold water tank 11 is a container for storing cold water, and is connected to the inlet of the multi-stage heat exchanger via the cold water pump 12 to provide cooling water for the heat exchanger. The high-temperature water tank 10 is a container for storing water that has been heated after heat exchange in the multi-stage heat exchanger, and is connected to the drain outlet of the multi-stage heat exchanger.

[0083] In the application of this application, in the above-mentioned air compression and storage system, the cold water tank 11 provides cooling water for the multi-stage heat exchanger to cool the high-temperature compressed air, and the heated water flows into the high-temperature water tank 10 for subsequent heat recovery or other treatment.

[0084] This application achieves the recycling of cooling water by setting up a cold water tank 11 and a high-temperature water tank 10, while facilitating the management and treatment of cooling water and improving the energy utilization efficiency of the system.

[0085] In summary, when two compressors, two heat exchangers, and two air separators are installed, the outlet of the first-stage compressor 1 is connected to the air-side inlet of the first-stage heat exchanger 5, the air-side outlet of the first-stage heat exchanger 5 is connected to the inlet of the first-stage air separator 7, the outlet of the first-stage air separator 7 is connected to the inlet of the second-stage compressor 2, the outlet of the second-stage compressor 2 is connected to the air-side inlet of the second-stage heat exchanger 6, the air-side outlet of the second-stage heat exchanger 6 is connected to the inlet of the second-stage gas-water separator 8, and the outlet of the second-stage gas-water separator 8 is sequentially connected to the low-pressure gas storage tank 3, the near-isothermal gas compressor 9, and the high-pressure gas storage tank 4.

[0086] The cold water tank 11 is connected to the inlet of the cold water pump 12. The outlet of the cold water pump 12 is connected to the water-side inlet of the primary heat exchanger 5 and the water-side inlet of the secondary heat exchanger 6. The water-side outlet of the primary heat exchanger 5 is connected to the high-temperature water tank 10, and the water-side outlet of the secondary heat exchanger 6 is connected to the high-temperature water tank 10.

[0087] The primary compressor 1 draws air from the atmosphere at the local atmospheric pressure, with an intake temperature of -10℃ to 30℃ and an exhaust temperature of 100℃ to 200℃. The secondary compressor 2 has an intake temperature of 30℃ to 50℃ and an exhaust temperature of 100℃ to 200℃. The exhaust pressures of both the primary compressor 1 and the secondary compressor 2 are constant.

[0088] The primary heat exchanger 5 and the secondary heat exchanger 6 exchange heat through water and compressed gas in the gas path. The water is stored in a high-temperature water tank 10 and a cold water tank 11. The temperature range of the water in the high-temperature water tank 10 is 180℃ to 200℃, and the temperature range of the water in the cold water tank 11 is 20℃ to 50℃.

[0089] The working process of a near-isothermal compression system is as follows: The first-stage compressor 1 compresses atmospheric air to obtain compressed gas, which then enters the second-stage compressor 2 after passing through the first-stage gas-water heat exchanger 5 and the first-stage air separator 7. In the first-stage air separator 7, the internal moisture is separated out, and the dry air enters the second-stage compressor 2, thus protecting it.

[0090] Compressed air, after being pressurized by a two-stage compressor 2, passes sequentially through a two-stage gas-water heat exchanger 6 and a two-stage air separator 8 before entering a low-pressure storage tank 3. After being pressurized by a near-isothermal compressor 9, it is finally stored in a high-pressure storage tank 4. The pressurized gas has a higher pressure than the air inside the high-pressure storage tank 4, facilitating its flow into the tank. Without the near-isothermal compressor 9, compressed air cannot enter the high-pressure storage tank because its pressure after compression must always be higher than the tank's pressure to enter.

[0091] The water in the cold water tank 11 is pressurized by the cold water pump 12 and then enters the first-stage gas-water heat exchanger 5 and the second-stage gas-water heat exchanger 6, respectively. After exchanging heat with the compressed air from the outlets of the first-stage compressor 1 and the second-stage compressor 2, the water enters the high-temperature water tank 10.

[0092] The above embodiments are merely exemplary embodiments of this application and are not intended to limit this application. The scope of protection of this application is defined by the claims. Those skilled in the art can make various modifications or equivalent substitutions to this application within its substance and scope of protection, and such modifications or equivalent substitutions should also be considered to fall within the scope of protection of this application.

Claims

1. A near-isothermal gas compression device, characterized by, include: The air cylinder has its air inlet connected to a low-pressure air tank. A gas-water separator, the air inlet of which is connected to the exhaust port of the compressor cylinder, is used to separate the gas and water in the gas discharged from the compressor cylinder. The exhaust port of the gas-water separator is connected to a high-pressure gas storage tank. A water supply tank is connected to the exhaust port of the compressed air cylinder, and the water inlet of the water supply tank is connected to the drain port of the air-water separator. The radiator has its inlet connected to the drain outlet of the air compressor and the drain outlet of the water tank, respectively, for dissipating heat from the water entering the radiator. The water injection piston has its inlet connected to the outlet of the radiator, and its outlet connected to the inlet of the air compressor. The water injection piston draws water to reduce the pressure inside the compressed air cylinder, allowing gas from the low-pressure gas storage tank to be injected into the compressed air cylinder. The water injection piston pressurizes the low-pressure gas in the compressed air cylinder, and the injected water absorbs the heat generated by compression, so that the compressed air is sent to the high-pressure gas storage tank through the gas-water separator.

2. The near-isothermal gas compression device of claim 1, wherein, A first shut-off valve is provided between the low-pressure gas storage tank and the air inlet of the air compressor. The air outlet of the air compressor is connected to one end of a second shut-off valve, and the other end of the second shut-off valve is connected to the gas-water separator and the water replenishment tank, respectively.

3. The near-isothermal gas compression device of claim 1, wherein, A check valve is provided between the gas-water separator and the high-pressure gas storage tank.

4. The near-isothermal gas compression device of claim 1, wherein, A sixth shut-off valve is provided between the drain outlet of the gas-water separator and the inlet of the water supply tank, and a third shut-off valve is provided between the outlet of the water supply tank and the inlet of the radiator.

5. The near-isothermal gas compression apparatus of claim 1, wherein, The water injection piston has a driving structure at one end, and a fourth shut-off valve is provided between the drain port of the water injection piston and the water inlet of the air compressor. The air compressor is provided with a nozzle that communicates with the fourth shut-off valve. The nozzle is used to atomize the cold water entering the air compressor.

6. The near-isothermal gas compression device of claim 1, wherein, A fifth shut-off valve is provided between the outlet of the radiator and the inlet of the water injection piston.

7. A near-isothermal compression system characterized by, The near-isothermal compressor device as described in any one of claims 1-6 further includes: A multi-stage compressor, each stage connected to a corresponding electric motor; A multi-stage heat exchanger is provided between two adjacent compressors; A multi-stage air separator, which is connected to the outlet of the corresponding heat exchanger; The low-pressure gas storage tank has its inlet connected to the final stage air separator and its outlet connected to the inlet of the near-isothermal compressor. The high-pressure gas storage tank has its inlet connected to the outlet of the near-isothermal gas compressor.

8. The near-isothermal compression system of claim 7, wherein, The near-isothermal compression system also includes: A cold water tank is connected to the inlet of the multi-stage heat exchangers via a cold water pump. The high-temperature water tank is connected to the drain outlet of each of the multiple heat exchangers.

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