Low water consumption compressed air energy storage system

Abstract

The utility model relates to compressed air energy storage system technical field provides a kind of low water consumption compressed air energy storage system, including compression subsystem, turbine subsystem, heat storage system, cooling system and gas reservoir, and compression subsystem includes compressor unit, gas-water heat exchanger and gas-water cooler;Turbine subsystem includes turbine unit and gas-water heater;Heat storage system includes high-temperature water tank, low-temperature water tank, high-temperature pump and low-temperature pump, the air main pipeline of the gas reservoir to first heater is replaced by the air cooling sleeve pipe that can pass cooling water in the utility model, under the premise that not affecting system main gas pipeline flow efficiency, cooling system high-temperature water is introduced using pipeline interlayer and is cooled. Realize the independent cyclic utilization of system cold energy, reduce the dependence on external cold source, reduce plant water consumption, simultaneously optimize system energy flow by heat exchange, improve compressed air energy storage system overall efficiency, make energy more efficient conversion and utilization in "energy storage-energy release" cycle.

Description

Technical Field

[0001] This utility model relates to the technical field of compressed air energy storage systems, and in particular to a low-water-consumption compressed air energy storage system. Background Technology

[0002] Large-scale compressed air energy storage power stations, as an important energy storage technology, operate by using surplus electricity to drive compressor units to compress air during off-peak hours and storing the compressed air in underground caves, abandoned mines, and other spaces. During peak hours, the stored compressed air is released to drive turbine units (expanders) to generate electricity, thereby achieving efficient storage and flexible allocation of electrical energy and playing a key role in peak shaving and valley filling in the power system.

[0003] However, large-scale compressed air energy storage power plants currently face two prominent technical challenges during operation: On the one hand, the system operation generates a large amount of low- and medium-grade heat energy, which needs to be dissipated by closed-circuit cooling towers. When the return water temperature of the closed-circuit cooling tower exceeds the air-cooling limit, the spray pump must be activated to enhance heat dissipation by spraying water. This process directly leads to a significant increase in the power plant's water consumption. For water-scarce regions, the plant's water consumption quota has become a major bottleneck restricting the promotion and development of large-scale compressed air energy storage power plants in these areas.

[0004] On the other hand, during the turbine energy release process of a compressed air energy storage system, the storage tank continuously releases high-pressure air. This high-pressure air absorbs heat during expansion, causing the air temperature from the storage tank to the turbine inlet to gradually decrease, forming usable cold energy. Currently, this cold energy is typically extracted and utilized by adding heat exchangers to the air ducts. However, this method inevitably increases the pressure loss in the ducts, thus affecting the system's energy conversion efficiency and hindering the optimization of the overall system performance. Utility Model Content

[0005] The purpose of this invention is to provide a low-water-consumption compressed air energy storage system, which solves the above-mentioned problems by using this device.

[0006] To solve the above-mentioned technical problems, this utility model provides the following technical solution: a low-water-consumption compressed air energy storage system, including a compression subsystem, a turbine subsystem, a heat storage system, a cooling system and an air storage tank, wherein the compression subsystem includes a compressor unit, an air-water heat exchanger and an air-water cooler; The turbine subsystem includes the turbine unit and the gas-water heater; The thermal storage system includes a high-temperature water tank, a low-temperature water tank, a high-temperature pump, and a low-temperature pump; The cooling system includes a closed cooling tower, a cooling pump, cooling pipe sleeves, valve one, valve two, valve three, valve four and valve five. The components are connected by pipes to form a system loop.

[0007] Preferably, the cooling pipe sleeve is arranged in the piping system from the gas storage tank to the first-stage heat exchanger, and the number of cooling pipe sleeves is the same as the number of main gas pipes in the compressed air energy storage system.

[0008] Preferably, the diameter of the internal cooling water pipe is larger than the diameter of the air pipe.

[0009] Preferably, metal fins are arranged inside the internal cooling water pipe, and the metal fins are tightly integrated with the outside of the air pipe.

[0010] Preferably, the metal fins can be arranged longitudinally along the flow direction of the pipeline, or they can be arranged laterally along the flow direction of the pipeline.

[0011] Preferably, the cooling sleeve can cover the entire piping system from the gas storage tank to the first-stage heat exchanger, or it can be arranged in sections.

[0012] Preferably, expansion joints are provided on both sides of the cooling sleeve.

[0013] Compared with the prior art, the beneficial effects of this utility model are as follows: 1. This utility model provides a low-water-consumption compressed air energy storage system. The main air pipeline from the air storage tank to the primary heater is replaced with an air-cooled jacket that allows cooling water to flow through. Without affecting the flow efficiency of the main air pipeline (because the diameter of the air pipeline inside the jacket is the same as the original main air pipeline diameter, ensuring that the pressure loss of the main air pipeline remains unchanged), high-temperature water from the cooling system is introduced through the pipe jacket for cooling. This achieves autonomous recycling of the system's cold energy, reducing dependence on external cold sources and lowering plant water consumption. Simultaneously, it optimizes the system's energy flow through heat exchange, improving the overall efficiency of the compressed air energy storage system and allowing for more efficient energy conversion and utilization in the "energy storage-release" cycle.

[0014] 2. This utility model provides a low-water-consumption compressed air energy storage system that intelligently switches cooling modes (self-cooling mode and water-saving cooling mode) based on the output air temperature of the air storage tank, effectively improving the operating range of the closed-circuit cooling tower's air-cooling mode. When the output air temperature of the air storage tank is lower than the water-saving temperature, the system flexibly adjusts the return water valve of the cooling system in conjunction with the status of the closed-circuit cooling tower's spray pump, fully utilizing the air-cooling capacity of the closed-circuit cooling tower, reducing the frequency of water-cooling mode activation, and further reducing plant water consumption. Simultaneously, independent of the closed-circuit cooling tower's own cooling mode switching logic, it ensures the autonomy and stability of the system's cooling control, optimizes system operating efficiency, and helps the compressed air energy storage system achieve a balance between water conservation and high-efficiency operation. Attached Figure Description

[0015] Figure 1This is a schematic diagram of the compressed air energy storage system of this utility model; Figure 2 This is a schematic diagram of the cross-sectional structure of the air-cooled jacket of this utility model; Figure 3 This is a side view cross-sectional structural diagram of the air-cooled jacket of this utility model.

[0016] The following are the labels in the diagram: 1. Closed-loop cooling tower; 2. Cooling pump; 3. Turbine unit; 4. Gas-water heater; 5. Cooling pipe sleeve; 6. Gas storage tank; 61. Air duct; 62. Internal cooling water duct; 63. Metal fins; 7. Gas-water cooler; 8. High-temperature water tank; 9. High-temperature pump; 10. Low-temperature water tank; 11. Low-temperature pump; 12. Gas-water heat exchanger; 13. Compressor unit; 14. Valve 1; 15. Valve 2; 16. Valve 3; 17. Valve 4; 18. Valve 5. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0018] To further understand the content of this utility model, a detailed description of this utility model will be provided in conjunction with the accompanying drawings.

[0019] Combination Figures 1 to 3 As shown, the present invention provides a low-water-consumption compressed air energy storage system, which includes a compression subsystem, a turbine subsystem, a heat storage system, a cooling system, and an air storage tank 6. The compression subsystem includes a compressor unit 13, an air-water heat exchanger 12, and an air-water cooler 7. The turbine subsystem includes turbine unit 3 and gas-water heater 4; The thermal storage system includes a high-temperature water tank 8, a low-temperature water tank 10, a high-temperature pump 9, and a low-temperature pump 11; The cooling system includes a closed cooling tower 1, a cooling pump 2, a cooling pipe sleeve 5, valve 1 14, valve 2 15, valve 3 16, valve 4 17 and valve 5 18. The components are connected by pipes to form a system loop.

[0020] Cooling sleeve 5 is arranged in the piping system from gas storage 6 to the first-stage heat exchanger. The number of cooling sleeve 5 pipes is the same as the number of main gas pipes in the compressed air energy storage system.

[0021] The diameter of the air pipe 61 inside the cooling pipe sleeve 5 is consistent with the diameter of the original system's main air pipe. The diameter of the internal cooling water pipe 62 is larger than that of the air pipe 61. The diameter of the internal cooling water pipe 62 is 110% to 130% of the diameter of the air pipe 61, so as to ensure that the design flow rate of the internal cooling water pipe 62 meets the rated flow rate of the cooling system.

[0022] Metal fins 63 are arranged inside the internal cooling water pipe 62. The metal fins 63 are tightly connected to the outside of the air pipe 61. The metal fins 63 can be arranged longitudinally or laterally along the flow direction of the pipe to improve the heat exchange efficiency of the casing. The water flow direction of the internal cooling water pipe 62 is counter-current to the flow direction of the air pipe 61.

[0023] The metal fins 63 can be arranged longitudinally along the flow direction of the pipeline, or they can be arranged laterally along the flow direction of the pipeline.

[0024] The cooling pipe sleeve 5 can cover the entire piping system from the gas storage tank 6 to the primary heat exchanger, or it can be arranged in sections.

[0025] Expansion joints are provided on both sides of the cooling sleeve 5. The elastic deformation of the expansion joints absorbs the thermal expansion and contraction stress caused by the alternating heating and cooling of the air duct 61, and can also help prevent deformation caused by uneven heating and cooling of the air duct 61. Furthermore, the cooling sleeves 5 can be connected in parallel to improve heat exchange efficiency and reduce the length of the sleeves.

[0026] Specifically, the cooling pipe sleeve 5 can cover the entire piping system from the gas storage tank 6 to the primary heat exchanger, or it can be arranged in sections; the length of the cooling pipe sleeve 5 can be calculated according to a specific formula.

[0027] The specific method for calculating the sleeve length is as follows: The sleeve length L (m) can be obtained by solving the following system of equations simultaneously:

[0028] q w Rated flow rate of internal cooling water (kg / s); q α The rated flow rate for the air duct is 61 kg / s; C p.α The specific heat capacity of air is J / kg·℃; C p.w The specific heat capacity of the internal cooling water is J / kg·℃; T w.in , T w.out The input and output temperatures of the internal cooling water are in °C. T α.in , T w.out The air input and output temperatures are in °C. d For air ducts with a diameter of 61 m; α The overall heat transfer coefficient is expressed in units of 1000 ppm. W / (m 2 ·℃） .

[0029] Working principle: Phase A, Compressed Energy Storage Phase: When the system enters compression energy storage mode, the cooling system executes self-cooling mode: Close the return water main valve 14 and open the valve 2 15. Use the cooling pump 2 to drive the cooling medium, such as cold water, through the air-water cooler 7, air-water heater 4 and other components to cool the high-temperature compressed air generated by the compressor unit 13, so as to prevent the air from expanding and evaporating excessively due to high temperature and ensure that the compressed air is stored in a stable state. If turbine unit 3 is in the turning gear state (equipment start-up and shutdown transition), valve 316 needs to be opened to allow the cooling medium to flow through turbine unit 3, carry away the frictional heat during the turning gear process, and maintain the low-temperature standby environment of turbine unit 3.

[0030] Phase B, High-Pressure Gas Storage Phase: During the high-pressure gas storage phase, the cooling system maintains self-cooling mode: Relying on the counter-current heat exchange of the cooling pipe sleeve 5 (internal cooling water and air flow in opposite directions, combined with the enhanced heat exchange of metal fins 63), the air temperature inside the gas storage 6 is continuously regulated to suppress air evaporation and pressure abnormalities caused by fluctuations in ambient temperature. The high-temperature water tank 8, low-temperature water tank 10, and high-temperature pump 9 and low-temperature pump 11 of the heat storage system work together to store the waste heat from the compression stage, preparing for subsequent recycling and reuse, and realizing the cascade utilization of energy.

[0031] Stage C, Turbine Energy Release Stage: When the turbine releases energy, the system switches the cooling mode according to the output air temperature of gas storage tank 6: Scenario a: Continuing the self-cooling mode, valve 14 is closed and valve 2 is opened. The cooling medium passes through the cooling pipe sleeve 5, the gas-water heat exchanger 12, etc., to cool the high-temperature air released from the gas storage tank 6, ensuring the stable intake temperature of the turbine unit 3 and improving the energy conversion efficiency. Scenario b, temperature below the water-saving temperature: Switch to water-saving cooling mode and monitor the status of the cooling tower spray pump in real time (although the closed cooling tower 1 mode is controlled by its own water temperature, this system needs to switch valves according to its status): If the spray pump is turned on (low external cooling demand / suitable ambient temperature), open valve 14 and close valve 25 to use the natural cooling capacity of the closed cooling tower 1 to assist in cooling and reduce the energy consumption of cooling pump 2; once the water-saving mode is entered and the valve switching is completed, the spray pump operating status will no longer be judged repeatedly, and low-temperature air will be continuously and stably provided for turbine energy release until the energy release ends.

[0032] Phase D, low-pressure gas storage phase, the cooling system operates in self-cooling mode: Similar to the high-pressure gas storage stage logic, relying on the counter-current heat exchange of the cooling pipe sleeve 5 and the synergy of the heat storage system, the air temperature and pressure inside the gas storage tank 6 are kept stable, air evaporation is suppressed, and preparation is made for the next cycle.

[0033] The system intelligently switches between cooling modes (self-cooling / water-saving cooling) and utilizes efficient heat exchange in the air-cooled jacket (counter-flow + finned reinforcement) to precisely regulate the temperature and pressure of compressed air throughout the entire "energy storage-release" process, suppressing air evaporation losses. Simultaneously, it is decoupled from the control logic of the closed-circuit cooling tower 1's cooling mode (air-cooled / water-cooled), allowing each to operate independently. By relying on the thermal storage system to recover residual energy, it achieves the dual goals of energy saving and efficient energy conversion, making the compressed air energy storage process more stable and offering greater energy efficiency advantages.

[0034] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0035] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A low water consumption compressed air energy storage system, characterized in that, It includes a compression subsystem, a turbine subsystem, a heat storage system, a cooling system and a gas storage tank (6), wherein the compression subsystem includes a compressor unit (13), a gas-water heat exchanger (12) and a gas-water cooler (7); The turbine subsystem includes a turbine unit (3) and a gas-water heater (4). The thermal storage system includes a high-temperature water tank (8), a low-temperature water tank (10), a high-temperature pump (9), and a low-temperature pump (11). The cooling system includes a closed cooling tower (1), a cooling pump (2), a cooling pipe sleeve (5), valve one (14), valve two (15), valve three (16), valve four (17) and valve five (18), and the components are connected by pipes to form a system loop.

2. The low-water-consumption compressed air energy storage system according to claim 1, characterized in that: The cooling sleeve (5) is arranged in the pipeline system from the gas storage tank (6) to the first heat exchanger. The number of cooling sleeve (5) pipes is the same as the number of main gas pipes of the compressed air energy storage system.

3. The low-water-consumption compressed air energy storage system according to claim 1, characterized in that: The diameter of the internal cooling water pipe (62) is larger than that of the air pipe (61).

4. The low-water-consumption compressed air energy storage system according to claim 3, characterized in that: Metal fins (63) are arranged inside the internal cooling water pipe (62), and the metal fins (63) are tightly connected to the outside of the air pipe (61).

5. The low-water-consumption compressed air energy storage system according to claim 4, characterized in that: The metal fins (63) can be arranged longitudinally along the flow direction of the pipeline, or they can be arranged laterally along the flow direction of the pipeline.

6. The low-water-consumption compressed air energy storage system according to claim 1, characterized in that: The cooling sleeve (5) can cover the entire pipeline system from the gas storage tank (6) to the primary heat exchanger, or it can be arranged in sections.

7. The low-water-consumption compressed air energy storage system according to claim 1, characterized in that: Expansion joints are provided on both sides of the cooling sleeve (5).

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