Compressed air energy storage system

Abstract

The invention belongs to the technical field of energy storage, and discloses a compressed air energy storage system, an energy storage unit comprises an energy storage unit, an air storage tank, an energy release unit, a storage unit and a temperature adjusting unit, the energy storage unit comprises an air input pipe, a compressor unit and an energy storage heat exchanger, and the compressor unit is connected with the energy storage heat exchanger; the air storage tank is provided with an air inlet and an air outlet; the energy release unit comprises a turbine unit, an energy release heat exchanger and an air output pipe, and the turbine unit is connected with the energy release heat exchanger; the storage unit comprises a hot water tank and a cold water tank; the temperature adjusting unit comprises a temperature adjusting inlet mother pipe, a temperature adjusting outlet mother pipe and a heat exchange pipe, the temperature adjusting inlet mother pipe is connected with the hot water tank and the cold water tank, the temperature adjusting inlet mother pipe is connected with the heat exchange pipe, the temperature adjusting outlet mother pipe is connected with the heat exchange pipe, and at least part of the heat exchange pipe is located in the air storage tank. In this way, heat in the hot water tank and the cold water tank and system cooling water can be used for adjusting the temperature in the air storage tank.

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] In order to ensure the safe and stable operation of the power system, energy storage technology is needed to balance the 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 the compressed air is released during peak periods of electricity consumption to enter the 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 increase during the gas storage process, making it difficult for the pressure vessel to store enough air. The temperature in the pressure vessel will decrease during the gas release process, making it difficult for the pressure vessel to release 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 a pressure vessel, the temperature in the pressure vessel may change with the ambient temperature. Under extremely low temperature gas release conditions, the temperature in the pressure vessel will further decrease, and may even be lower than the lower limit of the use 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 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; an air storage tank, 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; 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 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; 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 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 mother pipe, a temperature control outlet mother pipe and a heat exchange tube, the input end of the temperature control inlet mother pipe is connected to the hot water tank and the cold water tank, the output end of the temperature control inlet mother pipe is connected to the input end of the heat exchange tube, the input end of the temperature control outlet mother pipe is connected to the output end of the heat exchange tube, the output end of the temperature control outlet mother 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 arranged corresponding to one gas storage tank. The two heat exchange main pipes are respectively connected to the temperature control inlet mother pipe and the temperature control outlet mother pipe. The first heat exchange branch pipe and the second heat exchange branch pipe are both arranged 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 arranged 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 input pipe and a cooling water output pipe, both of which are connected to the energy storage unit and are used to cool the air in the compressor unit, the temperature regulating inlet main pipe is connected to a cooling pipe, the output end of the cooling water input 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 regulating inlet main pipe, and the temperature regulating outlet main pipe is connected to the cooling water output pipe.

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

[0013] Preferably, the energy release unit further comprises 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-adjusting 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-adjusting inlet main pipe and the temperature-adjusting 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 comprises an energy storage unit, an air storage tank, an energy release unit, a storage unit and a temperature control unit. The energy storage unit comprises 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 comprises 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, and 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 comprises 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 mother pipe, a temperature control outlet mother pipe and a heat exchange tube, the input end of the temperature control inlet mother pipe is connected to both the hot water tank and the cold water tank, the output end of the temperature control inlet mother pipe is connected to the input end of the heat exchange tube, the input end of the temperature control outlet mother pipe is connected to the output end of the heat exchange tube, and the output end of the temperature control outlet mother 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-control 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-control outlet main pipe can collect the cooled or heated medium and return it to the system, so as to maintain a constant temperature environment in the gas tank, thereby improving the gas storage stability and safety of the gas tank. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

[0023] In the figure:

[0024] 1. Energy storage unit; 11. Air input 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 output 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 in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0026] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

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

[0028] In the description of this embodiment, the terms "upper", "lower", "right", etc., directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0029] See also 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 by 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 both ends of the air storage tank 2, and the output end of the compressor unit is connected to the air inlet 21.

[0030] See also 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 a plurality of 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 arranged 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 load 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 load 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, thereby heating the compressed air 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 set 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 also 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 tube 53. The input end of the temperature control inlet main pipe 51 is connected to both 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 tube 53. The input end of the temperature control outlet main pipe 52 is connected to the output end of the heat exchange tube 53. The output end of the temperature control outlet main pipe 52 is connected to the cold water tank 42. The heat exchange tube 53 is at least partially located inside the gas storage tank 2 to adjust 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 mother pipe 51 can accept different cold source and heat source media in the system, the temperature control outlet mother pipe 52 can collect the cooled or heated medium and return it to the system, and the medium with higher temperature in the hot water tank 41 can enter the heat exchange tube 53 through the temperature control inlet mother pipe 51. Since the heat exchange tube 53 is at least partially located in the gas storage tank 2, the heat exchange tube 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 deflation process, so as to maintain a constant temperature environment in the gas storage tank 2, thereby maintaining a stable gas storage capacity and improving the safety performance of the gas storage tank 2.

[0037] It can be understood that the temperature-regulating inlet mother pipe 51, the gas storage tank 2, and the temperature-regulating outlet mother pipe 52 are all connected by pipes. Similarly, the hot water tank 41 and the temperature-regulating inlet mother pipe 51, the cold water tank 42 and the temperature-regulating inlet mother pipe 51, and the cold water tank 42 and the temperature-regulating outlet mother pipe 52 can be connected by pipes, and valves can be correspondingly arranged on the pipes to control the flow of the medium. The settings of the pipes and valves are prior arts 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 of 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 0.2Mpa more than the saturated pressure at the hot water temperature of the corresponding hot water tank, the maximum pressure inside the gas tank 2 is 20Mpa, preferably, the internal pressure of the gas tank 2 is 10Mpa, and the temperature inside the gas tank 2 is preferably controlled at the local air 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 also 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 arranged 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 arranged 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, starting from the gas outlet 22 of the gas tank 2, the temperature can be adjusted so that the gas at the gas outlet 22 of the gas tank 2 can gradually flow and exchange with the gas at other positions, so that the temperature distribution of the gas in the gas tank 2 is more uniform, avoiding local overheating or overcooling, and facilitating the control of the temperature inside the gas tank 2 to keep it at 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 respectively set on the side wall adjacent to the air inlet 21. The specific setting position can be adjusted according to actual needs, which will not be elaborated here.

[0042] See also 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 arranged for one gas storage tank 2. The two heat exchange main pipes 531 are respectively connected to the temperature control inlet mother pipe 51 and the temperature control outlet mother pipe 52. The first heat exchange branch pipe 532 and the second heat exchange branch pipe 533 are both arranged 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 arranged 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 the 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 in 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 the bottom of the gas storage tank 2, which can enable the air in the gas storage tank 2 to generate convective heat exchange under the action of temperature difference, thereby avoiding temperature fluctuations inside the gas storage tank 2 caused by the external environment or gas storage 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 the present 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 as to achieve temperature regulation inside the gas storage tank 2 through metal heat conduction.

[0046] See also Figure 1In some embodiments, the thermostatic inlet mother pipe 51 is connected to the first heating tube 511, the second heating tube 512 and the third heating tube 513, the input end of the first heating tube 511 is connected to the energy release 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 mother 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 tank 2 through the first heating tube 511 and the temperature-adjusting inlet mother tube 51 and heat the temperature inside the gas 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 tank 2 through the second heating tube 512 and the temperature-adjusting inlet mother tube 51. If the temperature inside the gas 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 tank 2 through the third heating tube 513 and the temperature-adjusting inlet mother tube 51, thereby heating the air inside the gas tank 2, effectively utilizing the thermal energy under various working conditions, avoiding heat loss, and facilitating the gas tank 2 to maintain a constant temperature. When the external ambient temperature is too low, the internal temperature of the gas tank 2 can be prevented from being lower than the lower limit of the use temperature of the gas tank 2 material, thereby improving the safety performance of the gas tank 2.

[0048] See also Figure 1 In some embodiments, the compressed air energy storage system also 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 input pipe 61 and then transports it to the outside through the cooling water output 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 can be understood 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 also Figure 1 In some embodiments, the energy storage unit 1 further includes a first heat exchanger 14, which is connected to the cooling water input pipe 61, the compressor unit, and the cooling water output pipe 62. In this embodiment, three first heat exchangers 14 are provided, two of which are correspondingly 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, that is, the number of the first heat exchangers 14 is the same as the number of the 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 transported by the cooling water inlet pipe 61 to further cool the compressed air for further compression, thereby improving the compression efficiency and storing the compression heat energy for use in adjusting the temperature inside the gas storage tank 2, so that the inside of the gas storage tank 2 can be kept 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 also Figure 1 In some embodiments, the energy release unit 3 further includes a second heat exchanger 34 , an input end of the second heat exchanger 34 is connected to an output end of the energy release heat exchanger 32 , and a cooling water input pipe 61 and a 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 release heat exchanger 32 located upstream of the turbine 31, and the corresponding output end is connected to the cold water tank 42, so that the medium output by the energy release 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 heated in the 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 also Figure 1In some embodiments, the output end of the temperature control outlet main pipe 52 is connected to a cooling return pipe 521 and a 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 lower temperature to the gas storage tank 2 through the cooling pipe 514 and the temperature adjustment inlet main pipe 51 and adjusts the air temperature in the gas storage tank 2. The medium after compressed air cooling is discharged to the outside through the temperature adjustment 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 deflation and causing temperature fluctuations; and the output end of the second heat exchanger 34 and the output end of the cooling return pipe 521 are connected to the cooling water output pipe 62 after merging, so that the pipeline is further simplified.

[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 also Figure 1 and Figure 2 In some embodiments, multiple gas storage tanks 2 are arranged in parallel, and the multiple gas storage tanks 2 are connected to the temperature adjustment inlet main pipe 51 and the temperature adjustment outlet main pipe 52. In this embodiment, each gas storage tank 2 is correspondingly provided with a heat exchange pipe 53, and further, a valve may also be provided on the heat exchange pipe 53 to achieve temperature adjustment of 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 behind 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 inside of the gas storage tank 2 can maintain a constant temperature, reduce the impact of the external environment and the gas storage and deflation 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 the heat utilization rate and reduce heat loss.

[0063] It can be understood that the number of the 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 also 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 component 23 and the pressure measuring component 24 can facilitate the staff to select the temperature and flow rate of the medium entering the gas storage tank 2 through the temperature-adjusting 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 keep it within a suitable range, avoiding the impact of the gas storage capacity and gas discharge capacity of the gas storage tank 2 due to the compressed air temperature being too high or too low.

[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, and 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 temperature and water volume of the medium 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 the energy storage mode, the compressor 12 consumes electric energy and compresses the air delivered by the air input pipe 11. The compressed air is delivered to the air storage tank 2 for storage. The cooling water pump 63 is started to cool the compressors 12 at each level through the cooling water input pipe 61 and the first heat exchanger 14, so that the air temperature at the input end of each level of the compressor 12 and inside the air storage tank 2 meets the design requirements. During the energy storage process, the temperature and air pressure inside the air storage tank 2 are detected by the temperature measuring component 23 and the pressure measuring component 24. When the temperature exceeds the system requirements, the flow rate of the cooling water pump 63 is increased, and the valve set at the input end of the cooling pipe 514 and the valve set at the output end of the cooling return pipe 521 are opened, so that the cooling medium cools the compressed gas in the air storage tank 2. At this time, after the medium in the first heat exchange branch pipe 532 in the air storage tank 2 exchanges heat with the compressed air, the air with a lower temperature sinks and the air with a higher temperature rises, so as to achieve natural convection and finally complete the cooling of 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 when the energy storage is close to the end, the temperature in 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 storage tank 2, and is heated by the energy release heat exchanger 32 and then 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 storage tank 2 In order to ensure the amount of deflated air, 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 tank 2 through the first heating pipe 511 and the temperature-adjusting inlet main pipe 51, and heat the compressed air in the gas tank 2 to keep the gas tank 2 at a constant temperature. After heating the medium in the gas tank 2, it is returned to the cold water tank 42 through the temperature-adjusting 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 amount of water in the cooling water pump 63 can be reduced to make full use of the stored heat. The medium in the second heat exchange branch 533 in the gas tank 2 exchanges heat with the compressed air, which can make the heated air rise and the colder air in the upper part fall, and form convection; in an extremely low temperature environment, if energy release and power generation are required, in order to prevent the temperature in the gas tank 2 from dropping below the operating temperature of the material of the gas tank 2, the second heating tube 512 and the third heating tube 513 can be further opened to make more stored heat available to ensure the safe operation of the gas 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 at the same time to increase the gas storage capacity of the gas 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 gas tank 2 is greatly affected by the external environment. Under extremely high temperatures or direct sunlight, the temperature in the gas tank 2 gradually rises, and the pressure also gradually rises. The cooling water pump 63 is turned on, and the cooling medium can cool the compressed air in the gas 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 gas 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 gas tank 2 to ensure safe and stable operation of the system.

[0071] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention shall be included in the protection scope 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 control unit (5), the temperature control unit (5) comprising 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 both 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 control the temperature 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 main heat exchange pipe (531), a first heat exchange branch pipe (532) and a second heat exchange branch pipe (533). Two main heat exchange pipes (531) are provided for one gas storage tank (2). The two main heat exchange pipes (531) are respectively connected to the temperature control inlet mother pipe (51) and the temperature control outlet mother pipe (52). The first heat exchange branch pipe (532) and the second heat exchange branch pipe (533) are both provided between the two main heat exchange pipes (531) and communicate with the two main heat exchange 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 temperature-adjusting inlet mother 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 temperature-adjusting inlet mother pipe (51).

5. 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), wherein the cooling unit (6) comprises a cooling water input pipe (61) and a cooling water output pipe (62), wherein 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, wherein the temperature regulating inlet main pipe (51) is connected to a cooling pipe (514), wherein the output end of the cooling water input pipe (61) is connected to the input end of the cooling pipe (514), wherein the output end of the cooling pipe (514) is connected to the input end of the temperature regulating inlet main pipe (51), and wherein the temperature regulating outlet main pipe (52) is connected to the cooling water output pipe (62).

6. The compressed air energy storage system according to claim 5, 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).

7. The compressed air energy storage system according to claim 5, 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.

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

9. The compressed air energy storage system according to any one of claims 1 to 8, 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-adjusting inlet main pipe (51) and the temperature-adjusting outlet main pipe (52).

10. The compressed air energy storage system according to any one of claims 1 to 8, characterized in that: 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 / or the gas storage tank (2) is connected to a pressure measuring component (24) for testing the internal pressure of the gas storage tank (2).

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