A compressed air energy storage system

Abstract

The present invention belongs to the field of energy storage technology and discloses a compressed air energy storage system. The energy storage unit includes an energy storage unit, an air storage tank, an energy release unit, a storage unit, and a temperature control unit. The energy storage unit includes an air input pipe, a compressor unit, and an energy storage heat exchanger, with the compressor unit connected to the energy storage heat exchanger. The air storage tank is provided with an air inlet and an air outlet. The energy release unit includes a turbine unit, an energy release heat exchanger, and an air output pipe, with the turbine unit connected to the energy release heat exchanger. The storage unit includes a hot water tank and a cold water tank. The temperature control unit includes a temperature control inlet main pipe, a temperature control outlet main pipe, and a heat exchange pipe. The temperature control inlet main pipe is connected to both the hot water tank and the cold water tank, the temperature control inlet main pipe is connected to the heat exchange pipe, and the temperature control outlet main pipe is connected to the heat exchange pipe. The heat exchange pipe is at least partially located inside the air storage tank. In this way, the temperature inside the air storage tank can be controlled by utilizing the heat in the hot water tank and the cold water tank as well as the system cooling water.

Description

Technical Field

[0001] The present invention relates to the field of energy storage technology, and in particular to a compressed air energy storage system. Background Art

[0002] To ensure the safe and stable operation of the power system, energy storage technology is needed to balance supply and demand. Compressed air energy storage is a common physical energy storage method.

[0003] Compressed air energy storage systems usually require pipeline steel or pressure vessels to store gas. During periods of low electricity consumption, the air is compressed and stored through a compressor, and during periods of peak electricity consumption, the compressed air is released into a turbine to generate electricity.

[0004] However, when the pressure variation range in the pressure vessel is large, the temperature in the pressure vessel will fluctuate violently. The temperature in the pressure vessel will rise during the gas storage process, making it difficult for the pressure vessel to store enough air. The temperature in the pressure vessel will drop during the gas discharge process, making it difficult for the pressure vessel to discharge enough air. The changes in air density and pressure caused by temperature fluctuations will make it difficult to maintain a constant temperature in the pressure vessel. Moreover, when compressed air is stored in the pressure vessel, the temperature in the pressure vessel may change with the ambient temperature. Under extremely low temperature gas discharge conditions, the temperature in the pressure vessel will further drop, and may even be lower than the lower limit of the operating temperature of the pressure vessel material, posing a safety hazard. Summary of the Invention

[0005] The object of the present invention is to provide a compressed air energy storage system to solve the problem that the temperature in the pressure vessel is easily affected by the external environment and the air storage and release process and thus fluctuates.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] A compressed air energy storage system, comprising: an energy storage unit, the energy storage unit comprising an air input pipe, a compressor unit and an energy storage heat exchanger, the air input pipe being connected to the input end of the compressor unit, and the compressor unit being connected to the energy storage heat exchanger for heat exchange; an air storage tank, the air storage tank being provided with an air inlet and an air outlet, and the output end of the compressor unit being connected to the air inlet; an energy release unit, the energy release unit comprising a turbine unit, an energy release heat exchanger and an air output pipe, the input end of the turbine unit being connected to the air outlet of the air storage tank, the output end of the turbine unit being connected to the air output pipe, and the turbine unit being connected to the energy release heat exchanger for heat exchange; a storage unit, the storage unit comprising a hot water tank and a cold water tank, the output end of the energy storage heat exchanger being connected to the output end of the The inlet end is connected to the output end of the cold water tank, the output end of the energy storage heat exchanger is connected to the input end of the hot water tank, the input end of the energy release heat exchanger is connected to the output end of the hot water tank, and the output end of the energy release heat exchanger is connected to the input end of the cold water tank; a temperature control unit, the temperature control unit includes a temperature control inlet main pipe, a temperature control outlet main pipe and a heat exchange tube, the input end of the temperature control inlet main pipe is connected to the hot water tank and the cold water tank, the output end of the temperature control inlet main pipe is connected to the input end of the heat exchange tube, the input end of the temperature control outlet main pipe is connected to the output end of the heat exchange tube, and the output end of the temperature control outlet main pipe is connected to the cold water tank, and the heat exchange tube is at least partially located inside the gas storage tank to adjust the temperature inside the gas storage tank.

[0008] Preferably, the input end of the heat exchange tube and the air outlet of the gas tank are arranged on the same side of the gas tank, and the output end of the heat exchange tube and the air inlet are arranged on the same side of the gas tank.

[0009] Preferably, the heat exchange pipe includes a heat exchange main pipe, a first heat exchange branch pipe and a second heat exchange branch pipe. Two heat exchange main pipes are correspondingly provided for one gas storage tank. The two heat exchange main pipes are respectively connected to the temperature control inlet main pipe and the temperature control outlet main pipe. The first heat exchange branch pipe and the second heat exchange branch pipe are both provided between the two heat exchange main pipes and communicate with the two heat exchange main pipes. The first heat exchange branch pipe and the second heat exchange branch pipe are both provided in the gas storage tank.

[0010] Preferably, the temperature-regulating inlet main pipe is connected to a first heating tube, a second heating tube and a third heating tube, the input end of the first heating tube is connected to the energy-releasing heat exchanger, the input end of the second heating tube is connected to the output end of the hot water tank, the input end of the third heating tube is connected to the output end of the cold water tank, and the output ends of the first heating tube, the second heating tube and the third heating tube are all connected to the input end of the temperature-regulating inlet main pipe.

[0011] Preferably, the compressed air energy storage system also includes a cooling unit, which includes a cooling water inlet pipe and a cooling water output pipe. The cooling water inlet pipe and the cooling water output pipe are both connected to the energy storage unit and are used to cool the air in the compressor unit. The temperature control inlet main pipe is connected to a cooling pipe, the output end of the cooling water inlet pipe is connected to the input end of the cooling pipe, the output end of the cooling pipe is connected to the input end of the temperature control inlet main pipe, and the temperature control outlet main pipe is connected to the cooling water output pipe.

[0012] Preferably, the energy storage unit further includes a first heat exchanger, which is connected to the cooling water inlet pipe, the compressor unit, and the cooling water outlet pipe.

[0013] Preferably, the energy release unit further includes a second heat exchanger, the input end of the second heat exchanger is connected to the output end of the energy release heat exchanger, and the cooling water input pipe and the cooling water output pipe are both connected to the second heat exchanger for heat exchange.

[0014] Preferably, the output end of the temperature-regulating outlet main pipe is connected to a cooling return pipe and a heating return pipe, the output end of the cooling return pipe is connected to the second heat exchanger and the cooling water output pipe, and the output end of the heating return pipe is connected to the input end of the cold water tank.

[0015] Preferably, a plurality of the gas storage tanks are arranged in parallel, and the plurality of gas storage tanks are all connected to the temperature-regulating inlet main pipe and the temperature-regulating outlet main pipe.

[0016] Preferably, the gas tank is connected to a temperature measuring device for testing the internal temperature of the gas tank; and / or, the gas tank is connected to a pressure measuring device for testing the internal pressure of the gas tank.

[0017] Beneficial effects of the present invention:

[0018] A compressed air energy storage system includes an energy storage unit, an air storage tank, an energy release unit, a storage unit and a temperature control unit. The energy storage unit includes an air input pipe, a compressor unit and an energy storage heat exchanger. The air input pipe is connected to the input end of the compressor unit, and the compressor unit is connected to the energy storage heat exchanger for heat exchange; the air storage tank is provided with an air inlet and an air outlet, and the output end of the compressor unit is connected to the air inlet; the energy release unit includes a turbine unit, an energy release heat exchanger and an air output pipe. The input end of the turbine unit is connected to the air outlet of the air storage tank, the output end of the turbine unit is connected to the air output pipe, and the turbine unit is connected to the energy release heat exchanger for heat exchange; the storage unit includes a hot water tank and a cold water tank. The input end of the energy heat exchanger is connected to the output end of the cold water tank, the output end of the energy storage heat exchanger is connected to the input end of the hot water tank, the input end of the energy release heat exchanger is connected to the output end of the hot water tank, and the output end of the energy release heat exchanger is connected to the input end of the cold water tank; the temperature control unit includes a temperature control inlet main pipe, a temperature control outlet main pipe and a heat exchange tube, the input end of the temperature control inlet main pipe is connected to both the hot water tank and the cold water tank, the output end of the temperature control inlet main pipe is connected to the input end of the heat exchange tube, the input end of the temperature control outlet main pipe is connected to the output end of the heat exchange tube, and the output end of the temperature control outlet main pipe is connected to the cold water tank, and the heat exchange tube is at least partially located inside the gas storage tank to adjust the temperature inside the gas storage tank.

[0019] In this way, the compressor unit can not only compress the air to store energy, but also store the compressed heat energy in the hot water tank through the medium. The temperature-controlled inlet main pipe can accept media of different temperatures in the system and adjust the temperature inside the gas tank through the heat exchange pipe. The temperature-controlled outlet main pipe can collect the cooled or heated medium and return it to the system, so that the gas tank maintains a constant temperature environment, thereby improving the gas storage stability and safety of the gas tank. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a structural diagram of a compressed air energy storage system according to one embodiment of the present invention;

[0021] Figure 2 This is a schematic diagram of the partial structure of the air inlet and the air outlet of the air storage tank in one embodiment of the present invention;

[0022] Figure 3 This is a partial structural diagram showing the connection between the heat exchange main pipe and the gas storage tank in one embodiment of the present invention.

[0023] In the picture:

[0024] 1. Energy storage unit; 11. Air inlet pipe; 12. Compressor; 13. Energy storage heat exchanger; 14. First heat exchanger; 2. Air storage tank; 21. Air inlet; 22. Air outlet; 23. Temperature measuring element; 24. Pressure measuring element; 3. Energy release unit; 31. Turbine; 32. Energy release heat exchanger; 33. Air outlet pipe; 34. Second heat exchanger; 4. Storage unit; 41. Hot water tank; 411. Hot water pump; 42. Cold water tank; 421. Cold water pump; 5 , temperature control unit; 51, temperature control inlet main pipe; 511, first heating pipe; 512, second heating pipe; 513, third heating pipe; 514, cooling pipe; 52, temperature control outlet main pipe; 521, cooling return pipe; 522, heating return pipe; 53, heat exchange pipe; 531, heat exchange main pipe; 532, first heat exchange branch pipe; 533, second heat exchange branch pipe; 6, cooling unit; 61, cooling water inlet pipe; 62, cooling water outlet pipe; 63, cooling water pump. DETAILED DESCRIPTION

[0025] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It will be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all structures.

[0026] In the description of the present invention, unless otherwise expressly specified or limited, the terms "connected," "connected," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention in specific circumstances.

[0027] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0028] In the description of this embodiment, the terms "upper," "lower," "right," and other orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely for ease of description and simplified operation. They do not indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used solely for descriptive purposes and have no special meanings.

[0029] See Figure 1 and Figure 2 The present invention provides a compressed air energy storage system, comprising an energy storage unit 1, an air storage tank 2, an energy release unit 3, a storage unit 4 and a temperature control unit 5. The energy storage unit 1 comprises an air input pipe 11, a compressor unit (not shown in the figure) and an energy storage heat exchanger 13. The air input pipe 11 is connected to the input end of the compressor unit, and the compressor unit is connected to the energy storage heat exchanger 13 for heat exchange. The compressor unit comprises a plurality of compressors 12. In this embodiment, three compressors 12 are provided and two energy storage heat exchangers 13 are provided. The three compressors 12 are arranged in series to form a three-stage compressed energy storage. The two energy storage heat exchangers 13 are respectively arranged between two adjacent compressors 12, so that the air input from the air input pipe 11 is compressed by the three compressors 12 in sequence and then transported to the air storage tank 2. The air storage tank 2 is provided with an air inlet 21 and an air outlet 22. The air inlet 21 and the air outlet 22 are respectively arranged at the two ends of the air storage tank 2, and the output end of the compressor unit is connected to the air inlet 21.

[0030] See Figure 1 The energy release unit 3 includes a turbine unit (not shown in the figure), an energy release heat exchanger 32 and an air output pipe 33. The input end of the turbine unit is connected to the air outlet 22 of the gas storage tank 2, and the output end of the turbine unit is connected to the air output pipe 33. The turbine unit is connected to the energy release heat exchanger 32 for heat exchange. The turbine unit includes multiple turbines 31. In this embodiment, two turbines 31 are provided, and two energy release heat exchangers 32 are provided. The two energy release heat exchangers 32 are respectively connected to the input ends of the two turbines 31 through pipelines, and the two energy release heat exchangers 32 are respectively provided upstream of the two turbines 31, so that the gas output from the air outlet 22 of the gas storage tank 2 is heated and then enters the turbine 31 to generate electricity.

[0031] The storage unit 4 includes a hot water tank 41 and a cold water tank 42. The input end of the energy storage heat exchanger 13 is connected to the output end of the cold water tank 42, the output end of the energy storage heat exchanger 13 is connected to the input end of the hot water tank 41, the input end of the energy release heat exchanger 32 is connected to the output end of the hot water tank 41, and the output end of the energy release heat exchanger 32 is connected to the input end of the cold water tank 42.

[0032] Furthermore, a hot water pump 141 and a cold water pump 331 are respectively provided at the output end of the hot water tank 41 and the output end of the cold water tank 42 to achieve directional flow of the medium.

[0033] It should be noted that when the power grid needs peak regulation or is in a period of low electricity prices, the air enters the compressor unit through the air input pipe 11 and undergoes multi-stage compression to form compressed gas, which is then transported to the gas storage tank 2 for storage. The cold water pump 331 is started to allow the medium with a lower temperature in the cold water tank 42 to enter the energy storage heat exchanger 13. The energy storage heat exchanger 13 can transfer the absorbed compressed heat energy to the hot water tank 41 through the medium, thereby improving energy utilization. When the power grid needs peak regulation or is in a period of peak electricity prices, the compressed gas in the gas storage tank 2 is discharged into the turbine unit, and the hot water pump 141 is started to allow the medium with a higher temperature in the hot water tank 41 to enter the energy release heat exchanger 32, so that the compressed air is heated before entering the turbine 31, thereby improving the power generation efficiency of the turbine 31. The air after energy release is discharged to the outside of the system through the air output pipe 33.

[0034] It can be understood that the number of compressors 12, the number of energy storage heat exchangers 13, the number of turbines 31, and the number of energy release heat exchangers 32 can all be flexibly adjusted, and the number of compressors 12 can also be equal to the number of energy storage heat exchangers 13. In this embodiment, no energy storage heat exchanger 13 is provided at the output end of the last-stage compressor 12 because the last-stage compressor 12 mainly plays the role of regulating pressure, and the compressed air it outputs contains less compression heat and no longer stores heat.

[0035] See Figure 1 The temperature control unit 5 includes a temperature control inlet main pipe 51, a temperature control outlet main pipe 52 and a heat exchange pipe 53. The input end of the temperature control inlet main pipe 51 is connected to the hot water tank 41 and the cold water tank 42. The output end of the temperature control inlet main pipe 51 is connected to the input end of the heat exchange pipe 53. The input end of the temperature control outlet main pipe 52 is connected to the output end of the heat exchange pipe 53. The output end of the temperature control outlet main pipe 52 is connected to the cold water tank 42. The heat exchange pipe 53 is at least partially located inside the gas storage tank 2 to regulate the temperature inside the gas storage tank 2.

[0036] In this way, while the compressor unit compresses the air to store energy, the energy storage heat exchanger 13 can store the compressed heat energy in the hot water tank 41 through the medium. The temperature control inlet main pipe 51 can accept different cold source and heat source media in the system. The temperature control outlet main pipe 52 can collect the cooled or heated medium and return it to the system. The medium with higher temperature in the hot water tank 41 can enter the heat exchange pipe 53 through the temperature control inlet main pipe 51. Since the heat exchange pipe 53 is at least partially located in the gas storage tank 2, the heat exchange pipe 53 can exchange heat with the compressed air in the gas storage tank 2 and increase the temperature in the gas storage tank 2, thereby avoiding temperature fluctuations in the gas storage tank 2 due to the influence of the external environment or the gas storage and degassing process, maintaining a constant temperature environment in the gas storage tank 2, and thus maintaining a stable gas storage capacity, thereby improving the safety performance of the gas storage tank 2.

[0037] It can be understood that the temperature control inlet main pipe 51, the gas storage tank 2, and the temperature control outlet main pipe 52 are all connected by pipes. Similarly, the hot water tank 41 and the temperature control inlet main pipe 51, the cold water tank 42 and the temperature control inlet main pipe 51, and the cold water tank 42 and the temperature control outlet main pipe 52 can be connected by pipes, and valves can be set accordingly on the pipes to control the flow of the medium. The settings of the pipes and valves are existing technologies and are not listed in detail here. The type of medium can be adjusted according to actual needs. In this embodiment, the medium is pressurized water.

[0038] Furthermore, the maximum temperature of the medium in the hot water tank 41 is 200°C, the medium temperature range in the cold water tank 42 is 35°C-55°C, the pressure in the hot water tank 41 and the cold water tank 42 is 0.2 MPa higher than the saturation pressure at the hot water temperature of the hot water tank. The maximum pressure inside the gas storage tank 2 is 20 MPa. Preferably, the internal pressure of the gas storage tank 2 is 10 MPa. The temperature inside the gas storage tank 2 is preferably controlled at the local temperature of the compressed air energy storage system. The temperature range of the medium after being output from the hot water tank 41 and heating the turbine unit is 35°C-100°C.

[0039] See Figure 2 In some embodiments, the input end of the heat exchange tube 53 and the gas outlet 22 of the gas tank 2 are disposed on the same side of the gas tank 2, and the output end of the heat exchange tube 53 and the gas inlet 21 are disposed on the same side of the gas tank 2. That is, the flow direction of the compressed gas in the gas tank 2 is opposite to the flow direction of the medium in the heat exchanger.

[0040] In this way, by starting to adjust the temperature from the gas outlet 22 of the gas storage tank 2, the gas at the gas outlet 22 of the gas storage tank 2 can gradually flow and exchange with the gas at other positions, so that the temperature distribution of the gas in the gas storage tank 2 is more uniform, avoiding local overheating or overcooling, and facilitating the control of the temperature inside the gas storage tank 2 to maintain a constant temperature.

[0041] It can be understood that the input end of the heat exchange tube 53 can also be set on the same side as the air inlet 21 of the air storage tank 2, and the output end of the heat exchange tube 53 can be set on the same side as the air outlet 22 of the air storage tank 2. The input end and output end of the heat exchange tube 53 can also be set on the side wall adjacent to the air inlet 21 respectively. The specific setting position can be adjusted according to actual needs and will not be elaborated here.

[0042] See Figure 2 and Figure 3In some embodiments, the heat exchange pipe 53 includes a heat exchange main pipe 531, a first heat exchange branch pipe 532, and a second heat exchange branch pipe 533. Two heat exchange main pipes 531 are correspondingly provided for one gas storage tank 2. The two heat exchange main pipes 531 are respectively connected to the temperature control inlet main pipe 51 and the temperature control outlet main pipe 52. The first heat exchange branch pipe 532 and the second heat exchange branch pipe 533 are both provided between the two heat exchange main pipes 531 and communicate with the two heat exchange main pipes 531. The first heat exchange branch pipe 532 and the second heat exchange branch pipe 533 are both provided in the gas storage tank 2.

[0043] In this embodiment, the length directions of the first heat exchange branch pipe 532 and the second heat exchange branch pipe 533 are parallel to the length direction of the heat exchange pipe 53, and the first heat exchange branch pipe 532 and the second heat exchange branch pipe 533 are respectively arranged at the top and bottom of the gas storage tank 2. The heat exchange main pipe 531 passes through the gas storage tank 2 and is fixedly connected by plug-in welding. Both ends of the first heat exchange branch pipe 532 and the second heat exchange branch pipe 533 are bent and connected to the two heat exchange main pipes 531 and are integrally formed with the heat exchange main pipe 531.

[0044] In this way, the medium can enter the first heat exchange branch pipe 532 and the second heat exchange branch pipe 533 through the heat exchange main pipe 531, so that the first heat exchange branch pipe 532 and the second heat exchange branch pipe 533 evenly heat or cool the air in the gas storage tank 2, and the bending parts of the first heat exchange branch pipe 532 and the second heat exchange branch pipe 533 can absorb the stress during the heating and cooling process, thereby improving the temperature control effect; the first heat exchange branch pipe 532 and the second heat exchange branch pipe 533 are respectively arranged at the top and bottom of the gas storage tank 2, which can enable the air in the gas storage tank 2 to produce convective heat exchange under the action of the temperature difference, thereby avoiding temperature fluctuations inside the gas storage tank 2 caused by the external environment or gas degassing, thereby improving the gas storage stability and safety of the gas storage tank 2.

[0045] It can be understood that the specific structure of the heat exchange tube 53 can be flexibly adjusted according to actual needs. The heat exchange tube 53 can be a plain tube or a finned tube. In this embodiment, the heat exchange tube 53 is a finned tube. The finned tube can be a low-fin tube with a height of 0.3mm-1.2mm or a high-fin tube with a height of 3-25mm. No further examples are given here. In addition, the heat exchange main pipe 531, the first heat exchange branch pipe 532 and the second heat exchange branch pipe 533 can also be arranged outside the gas storage tank 2 and close to the gas storage tank 2, so that the temperature inside the gas storage tank 2 can be regulated by metal heat conduction.

[0046] See Figure 1In some embodiments, the thermostatic inlet main pipe 51 is connected to a first heating tube 511, a second heating tube 512 and a third heating tube 513. The input end of the first heating tube 511 is connected to the energy-releasing heat exchanger 32, the input end of the second heating tube 512 is connected to the output end of the hot water tank 41, the input end of the third heating tube 513 is connected to the output end of the cold water tank 42, and the output ends of the first heating tube 511, the second heating tube 512 and the third heating tube 513 are all connected to the input end of the thermostatic inlet main pipe 51.

[0047] In this way, the medium after the air input into the turbine 31 is heated by the energy-releasing heat exchanger 32 can continue to enter the gas storage tank 2 through the first heating tube 511 and the temperature-regulating inlet main tube 51 and heat the temperature inside the gas storage tank 2, thereby further utilizing the thermal energy. The medium with a higher temperature in the hot water tank 41 can also directly enter the gas storage tank 2 through the second heating tube 512 and the temperature-regulating inlet main tube 51. If the temperature inside the gas storage tank 2 is lower than the temperature inside the cold water tank 42, the medium in the cold water tank 42 can also enter the gas storage tank 2 through the third heating tube 513 and the temperature-regulating inlet main tube 51, thereby heating the air inside the gas storage tank 2, effectively utilizing the thermal energy under various working conditions, avoiding heat loss, and facilitating maintaining a constant temperature inside the gas storage tank 2. When the external ambient temperature is too low, the internal temperature of the gas storage tank 2 can be prevented from falling below the lower limit of the use temperature of the gas storage tank 2 material, thereby improving the safety performance of the gas storage tank 2.

[0048] See Figure 1 In some embodiments, the compressed air energy storage system further includes a cooling unit 6, which includes a cooling water input pipe 61 and a cooling water output pipe 62. The cooling water input pipe 61 and the cooling water output pipe 62 are both connected to the energy storage unit 1 and are used to cool the air in the compressor unit. The temperature control inlet main pipe 51 is connected to the cooling pipe 514. The output end of the cooling water input pipe 61 is connected to the input end of the cooling pipe 514. The output end of the cooling pipe 514 is connected to the input end of the temperature control inlet main pipe 51. The temperature control outlet main pipe 52 is connected to the cooling water output pipe 62.

[0049] In this embodiment, a cooling water inlet pipe 61 is provided for cooling the air temperature output by the compressor 12; a cooling water pump 63 is provided between the cooling water inlet pipe 61 and the compressor unit for directional flow of the medium.

[0050] In this way, the medium cools the compressor unit through the cooling water inlet pipe 61 and then is transported to the outside through the cooling water outlet pipe 62, which can further reduce the temperature of the compressed air entering the air storage tank 2, avoid the compressed air in the air storage tank 2 being too high and causing the air storage tank 2 to be unable to store sufficient air, and reduce the impact of the air storage process on the air storage tank 2.

[0051] It is understandable that the temperature of the cooling water can be flexibly adjusted according to actual needs. In this embodiment, the temperature range of the cooling water input by the cooling water input pipe 61 is 15°C-30°C.

[0052] See Figure 1 In some embodiments, the energy storage unit 1 further includes a first heat exchanger 14, which is connected to the cooling water inlet pipe 61, the compressor unit, and the cooling water outlet pipe 62. In this embodiment, three first heat exchangers 14 are provided, two of which are respectively provided downstream of the two energy storage heat exchangers 13, and the third first heat exchanger 14 is provided downstream of the last-stage compressor 12. In other words, the number of first heat exchangers 14 is the same as the number of compressors 12.

[0053] In this way, after the two energy storage heat exchangers 13 have respectively absorbed part of the compression heat energy generated by the first two stages of the compressor 12, the first heat exchanger 14 can allow the medium with a lower temperature delivered by the cooling water inlet pipe 61 to further cool the compressed air to facilitate further compression, thereby improving the compression efficiency and storing the compression heat energy for use in regulating the temperature inside the gas storage tank 2, so that the inside of the gas storage tank 2 can be maintained at a constant temperature.

[0054] It is understandable that the number of the first heat exchangers 14 may be different from the number of the compressors 12 , and the number and location of the first heat exchangers 14 may be adjusted according to actual working conditions, which is not limited in this embodiment.

[0055] See Figure 1 In some embodiments, the energy release unit 3 further includes a second heat exchanger 34 , the input end of the second heat exchanger 34 is connected to the output end of the energy release heat exchanger 32 , and the cooling water input pipe 61 and the cooling water output pipe 62 are both connected to the second heat exchanger 34 for heat exchange.

[0056] Among them, the second heat exchanger 34 is arranged downstream of the turbine 31, and the input end of the second heat exchanger 34 is connected to the output end of the energy-releasing heat exchanger 32 located upstream of the turbine 31, and its corresponding output end is connected to the cold water tank 42, so that the medium output by the energy-releasing heat exchanger 32 is cooled by the second heat exchanger 34 and then returned to the cold water tank 42 for storage. The other side of the second heat exchanger 34 is respectively connected to the cooling water input pipe 61 and the cooling water output pipe 62.

[0057] In this way, the cooling water inlet pipe 61 can not only cool the air in the compressor unit, but also cool the heat storage medium in the heated turbine unit, thereby improving the cooling efficiency and making the temperature of the medium and air in the entire system moderate, so as to facilitate stable energy storage and release.

[0058] See Figure 1In some embodiments, the output end of the temperature control outlet main pipe 52 is connected to the cooling return pipe 521 and the heating return pipe 522. The output end of the cooling return pipe 521 is connected to the second heat exchanger 34 and the cooling water output pipe 62. The output end of the heating return pipe 522 is connected to the input end of the cold water tank 42.

[0059] In this embodiment, the cooling water input pipe 61 transports the medium with a lower temperature into the gas storage tank 2 through the cooling pipe 514 and the temperature-regulating inlet main pipe 51 and adjusts the air temperature in the gas storage tank 2. The medium after the compressed air is cooled is discharged to the outside through the temperature-regulating outlet main pipe 52, the cooling return pipe 521, and the cooling water output pipe 62, thereby completing the cooling of the inside of the gas storage tank 2 and preventing the gas storage tank 2 from being affected by the external environment or the process of gas storage and degassing, thereby causing temperature fluctuations. In addition, the output end of the second heat exchanger 34 and the output end of the cooling return pipe 521 are merged and connected to the cooling water output pipe 62, thereby further simplifying the pipeline.

[0060] It is understandable that valves may be provided at the output end of the cooling return pipe 521, the output end of the heating return pipe 522, the input end of the first heating pipe 511, the input end of the second heating pipe 512, and the input end of the third heating pipe 513, which will not be elaborated here.

[0061] See Figure 1 and Figure 2 In some embodiments, multiple gas storage tanks 2 are arranged in parallel, and each of the multiple gas storage tanks 2 is connected to the temperature control inlet main pipe 51 and the temperature control outlet main pipe 52. In this embodiment, each gas storage tank 2 is provided with a corresponding heat exchange tube 53. Furthermore, the heat exchange tube 53 may also be provided with a valve to achieve temperature control for one or more of the gas storage tanks 2.

[0062] In this way, multiple gas storage tanks 2 can achieve temperature adjustment through heat exchange with the medium after the energy-releasing heat exchanger 32, the medium of the hot water tank 41, the medium of the cold water tank 42, and the medium input by the cooling water input pipe 61, so that the interior of the gas storage tank 2 can maintain a constant temperature, reduce the impact of the external environment and the gas storage and degassing process on the internal temperature of the gas storage tank 2, improve the gas storage stability of the gas storage tank 2, and can improve heat utilization and reduce heat loss.

[0063] It is understandable that the number of gas storage tanks 2 can be flexibly adjusted according to actual needs, and one gas storage tank 2 can also be provided; in this embodiment, three gas storage tanks 2 are provided.

[0064] See Figure 2 In some embodiments, the gas storage tank 2 is connected to a temperature measuring component 23 for testing the internal temperature of the gas storage tank 2 , and the gas storage tank 2 is connected to a pressure measuring component 24 for testing the internal pressure of the gas storage tank 2 .

[0065] In this way, the temperature measuring element 23 and the pressure measuring element 24 can facilitate the staff to select the temperature and flow rate of the medium entering the gas storage tank 2 through the temperature-regulating inlet main pipe 51 according to the temperature and pressure in the gas storage tank 2, thereby adjusting the temperature of the compressed gas in the gas storage tank 2 to maintain it within an appropriate range, avoiding affecting the gas storage capacity and gas discharge capacity of the gas storage tank 2 due to excessively high or low temperature of the compressed air.

[0066] It can be understood that one gas storage tank 2 can be connected to one temperature measuring component 23 and one pressure measuring component 24, or multiple temperature measuring components 23 and multiple pressure measuring components 24 can be set at different positions. The specific number and setting positions of the temperature measuring components 23 and the pressure measuring components 24 can be adjusted according to actual needs, and the specific structures of the temperature measuring components 23 and the pressure measuring components 24 can also be flexibly adjusted. In this embodiment, the temperature measuring component 23 is a thermocouple temperature sensor, and the pressure measuring component 24 is a pressure transmitter. The compressed air energy storage system may also include a control module (not shown in the figure), which is connected to the temperature measuring component 23, the pressure measuring component 24, and the valve to adjust the medium temperature and water volume delivered to the temperature regulating inlet main pipe 51 according to the temperature and pressure inside the gas storage tank 2, so as to maintain a moderate temperature inside the gas storage tank 2.

[0067] Furthermore, the operating principle of the compressed air energy storage system is as follows:

[0068] In energy storage mode, compressor 12 consumes electrical energy and compresses air delivered by air inlet pipe 11. The compressed air is then delivered to air storage tank 2 for storage. Cooling water pump 63 is activated, allowing the cooling medium to cool each stage of compressor 12 through cooling water inlet pipe 61 and first heat exchanger 14, ensuring that the air temperature at the input of each stage of compressor 12 and within air storage tank 2 meets the design requirements. During the energy storage process, temperature and pressure within air storage tank 2 are monitored by temperature measuring element 23 and pressure measuring element 24. When the temperature exceeds system requirements, the flow rate of cooling water pump 63 is increased, and the valve at the input end of cooling pipe 514 and the valve at the output end of cooling return pipe 521 are opened, allowing the cooling medium to cool the compressed air within air storage tank 2. At this point, the medium within first heat exchange branch pipe 532 within air storage tank 2 exchanges heat with the compressed air, causing the cooler air to sink while the warmer air to rise, achieving natural convection and ultimately cooling the air. After cooling is completed, the cooling medium returns to the system through the temperature-regulating outlet main pipe 52 and the cooling return pipe 521. If the gas storage capacity of the gas storage tank 2 needs to be further increased near the end of energy storage, the temperature inside the gas storage tank 2 can be further reduced, and the pressure inside the gas storage tank 2 can be reduced, thereby increasing the gas storage capacity.

[0069] In the energy release mode, the compressed air is released from the gas tank 2, and after being heated by the energy release heat exchanger 32, it expands in the turbine 31, driving the generator to generate electricity. The hot water pump 141 and the cooling water pump 63 are started, so that the medium with a higher temperature pumped out of the hot water tank 41 enters the energy release heat exchanger 32 and then enters the second heat exchanger 34 and exchanges heat with the cooling medium input by the cooling water input pipe 61, so that the medium that has heated the air in the turbine 31 is cooled by the cooling medium and then returns to the cold water tank 42; as the compressed gas is released, the pressure and temperature in the gas tank 2 are reduced. In order to ensure the amount of air released, the valve at the first heating pipe 511 can be opened to allow the heat storage medium with a higher temperature to enter the gas storage tank 2 through the first heating pipe 511 and the temperature-regulating inlet main pipe 51, and heat the compressed air in the gas storage tank 2 to maintain a constant temperature in the gas storage tank 2. After heating, the medium in the gas storage tank 2 is returned to the cold water tank 42 through the temperature-regulating outlet main pipe 52 and the heating return pipe 522. Since part of the heat energy in the medium is used to heat the compressed air, the water volume of the cooling water pump 63 can be reduced, so that the stored heat can be fully utilized. The medium in the second heat exchange branch 533 of the gas storage tank 2 exchanges heat with the compressed air, which can cause the heated air to rise and the cooler air at the top to descend, thereby forming convection. In an extremely low-temperature environment, if energy release and power generation are required, in order to prevent the temperature in the gas storage tank 2 from dropping below the operating temperature of the material of the gas storage tank 2, the second heating tube 512 and the third heating tube 513 can be further opened to utilize more stored heat and ensure the safe operation of the gas storage tank 2. Under normal ambient temperature, the first heating tube 511, the second heating tube 512 and the third heating tube 513 can also be opened simultaneously to increase the gas storage capacity of the gas storage tank 2, thereby improving the gas storage efficiency.

[0070] In the static mode, the compressor 12, the turbine 31 and the related pumps and valves do not work, and the compressed air energy storage system is in a static state. At this time, the internal temperature of the air tank 2 is greatly affected by the external environment. Under extremely high temperatures or direct sunlight, the temperature and pressure in the air tank 2 gradually rise. The cooling water pump 63 is turned on, and the cooling medium can cool the compressed air in the air tank 2; when the ambient temperature is low, the valves of the cold water pump 331 and the third heating pipe 513 can be opened, and the medium in the cold water tank 42 can be used to heat the air in the air tank 2. The cooled medium is returned to the cold water tank 42 through the heating circuit. Under extremely low temperatures, the cold water pump 331, the hot water pump 141, the first heating pipe 511, and the third heating pipe 513 can also be turned on at the same time, and the heat in the cold water tank 42 and the hot water tank 41 can be used to heat the air in the air tank 2 to ensure safe and stable operation of the system.

[0071] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention and are not intended to limit the embodiments of the present invention. A person skilled in the art would be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A compressed air energy storage system, characterized in that: include: An energy storage unit (1), the energy storage unit (1) comprising an air input pipe (11), a compressor unit, and an energy storage heat exchanger (13), the air input pipe (11) being connected to an input end of the compressor unit, and the compressor unit being connected to the energy storage heat exchanger (13) for heat exchange; An air storage tank (2), the air storage tank (2) being provided with an air inlet (21) and an air outlet (22), and the output end of the compressor unit being connected to the air inlet (21); An energy release unit (3), the energy release unit (3) comprising a turbine unit, an energy release heat exchanger (32) and an air output pipe (33), the input end of the turbine unit being connected to the air outlet (22) of the air storage tank (2), the output end of the turbine unit being connected to the air output pipe (33), and the turbine unit being connected to the energy release heat exchanger (32) for heat exchange; A storage unit (4), the storage unit (4) comprising a hot water tank (41) and a cold water tank (42), the input end of the energy storage heat exchanger (13) being connected to the output end of the cold water tank (42), the output end of the energy storage heat exchanger (13) being connected to the input end of the hot water tank (41), the input end of the energy release heat exchanger (32) being connected to the output end of the hot water tank (41), and the output end of the energy release heat exchanger (32) being connected to the input end of the cold water tank (42); A temperature adjustment unit (5), the temperature adjustment unit (5) comprising a temperature adjustment inlet main pipe (51), a temperature adjustment outlet main pipe (52) and a heat exchange pipe (53), the input end of the temperature adjustment inlet main pipe (51) being connected to both the hot water tank (41) and the cold water tank (42), the output end of the temperature adjustment inlet main pipe (51) being connected to the input end of the heat exchange pipe (53), the input end of the temperature adjustment outlet main pipe (52) being connected to the output end of the heat exchange pipe (53), the output end of the temperature adjustment outlet main pipe (52) being connected to the cold water tank (42), and the heat exchange pipe (53) being at least partially located inside the gas storage tank (2) to adjust the temperature inside the gas storage tank (2); The thermostatic inlet main pipe (51) is connected to a first heating pipe (511), a second heating pipe (512) and a third heating pipe (513); the input end of the first heating pipe (511) is connected to the energy-releasing heat exchanger (32); the input end of the second heating pipe (512) is connected to the output end of the hot water tank (41); the input end of the third heating pipe (513) is connected to the output end of the cold water tank (42); the output ends of the first heating pipe (511), the second heating pipe (512) and the third heating pipe (513) are all connected to the input end of the thermostatic inlet main pipe (51); The output end of the temperature-adjusting outlet main pipe (52) is connected to a heating return pipe (522), and the output end of the heating return pipe (522) is connected to the input end of the cold water tank (42); When the temperature in the gas storage tank (2) is lower than the temperature in the cold water tank (42), the medium in the cold water tank (42) enters the gas storage tank (2) through the third heating pipe (513) and the temperature-regulating inlet main pipe (51), thereby heating the air inside the gas storage tank (2).

2. The compressed air energy storage system according to claim 1, characterized in that: The input end of the heat exchange tube (53) and the air outlet (22) of the air storage tank (2) are arranged on the same side of the air storage tank (2), and the output end of the heat exchange tube (53) and the air inlet (21) are arranged on the same side of the air storage tank (2).

3. The compressed air energy storage system according to claim 1, characterized in that: The heat exchange pipe (53) comprises a heat exchange main pipe (531), a first heat exchange branch pipe (532), and a second heat exchange branch pipe (533). Two heat exchange main pipes (531) are correspondingly provided for one gas storage tank (2). The two heat exchange main pipes (531) are respectively connected to the temperature control inlet main pipe (51) and the temperature control outlet main pipe (52). The first heat exchange branch pipe (532) and the second heat exchange branch pipe (533) are both provided between the two heat exchange main pipes (531) and communicate with the two heat exchange main pipes (531). The first heat exchange branch pipe (532) and the second heat exchange branch pipe (533) are both provided in the gas storage tank (2).

4. The compressed air energy storage system according to claim 1, characterized in that: The compressed air energy storage system further comprises a cooling unit (6), the cooling unit (6) comprising a cooling water input pipe (61) and a cooling water output pipe (62), the cooling water input pipe (61) and the cooling water output pipe (62) both being connected to the energy storage unit (1) and being used to cool the air in the compressor unit, the temperature-regulating inlet main pipe (51) being connected to a cooling pipe (514), the output end of the cooling water input pipe (61) being connected to the input end of the cooling pipe (514), the output end of the cooling pipe (514) being connected to the input end of the temperature-regulating inlet main pipe (51), and the temperature-regulating outlet main pipe (52) being connected to the cooling water output pipe (62).

5. The compressed air energy storage system according to claim 4, characterized in that: The energy storage unit (1) further comprises a first heat exchanger (14), wherein the first heat exchanger (14) is connected to the cooling water input pipe (61), the compressor unit, and the cooling water output pipe (62).

6. The compressed air energy storage system according to claim 4, characterized in that: The energy release unit (3) further comprises a second heat exchanger (34), the input end of the second heat exchanger (34) being connected to the output end of the energy release heat exchanger (32), and the cooling water input pipe (61) and the cooling water output pipe (62) being both connected to the second heat exchanger (34) for heat exchange.

7. The compressed air energy storage system according to claim 6, characterized in that: The output end of the temperature-adjusting outlet main pipe (52) is connected to a cooling return pipe (521), and the output end of the cooling return pipe (521) is connected to both the second heat exchanger (34) and the cooling water output pipe (62).

8. The compressed air energy storage system according to any one of claims 1 to 7, characterized in that: A plurality of the gas storage tanks (2) are arranged in parallel, and the plurality of gas storage tanks (2) are all connected to the temperature-regulating inlet main pipe (51) and the temperature-regulating outlet main pipe (52).

9. The compressed air energy storage system according to any one of claims 1 to 7, characterized in that: The gas storage tank (2) is connected to a temperature measuring element (23) for testing the internal temperature of the gas storage tank (2); and / or the gas storage tank (2) is connected to a pressure measuring element (24) for testing the internal pressure of the gas storage tank (2).

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