Compressed air energy storage system coupled with extra-high temperature heat pump

Abstract

The invention relates to the technical field of compressed air energy storage power generation, in particular to a compressed air energy storage system coupled with an ultra-high temperature heat pump, which comprises a heat storage module, a heat pump module, a fused salt energy storage module and the like, the heat storage module is configured in the mode that a heat exchange working medium flowing out of the low-temperature storage tank absorbs heat of compressed air and flows into the high-temperature storage tank, and part of the heat exchange working medium flows out of the high-temperature storage tank to heat the compressed air entering the air expansion module and then flows back to the low-temperature storage tank. The heat pump module is configured as follows: part of the heat exchange working medium flows out from the high-temperature storage tank to heat air entering the heat pump compressor, and then flows back to the low-temperature storage tank; compressed air generated by the heat pump compressor exchanges heat energy to the fused salt, the fused salt is stored in the fused salt energy storage module, and then the fused salt flows into the heat pump expansion machine for power generation. The heat pump module is coupled, surplus heat energy is completely utilized, and after a high-temperature heat exchange working medium is used by the heat pump module, backflow parameters can meet the circulation conditions of heat storage and heat release of the heat storage module.

Description

Technical Field

[0001] This invention relates to the field of compressed air energy storage and power generation technology, and specifically to a compressed air energy storage system coupled with an ultra-high temperature heat pump. Background Technology

[0002] Compressed air energy storage has the advantages of large scale, low cost, and green environmental protection, and has great development potential. However, existing compressed air energy storage systems have certain problems.

[0003] Firstly, in the energy storage process of a compressed air energy storage system, air at normal temperature and pressure is compressed by a compressor to form high-temperature, high-pressure air. The heat energy of the air during compression is usually collected and stored (i.e., a thermal storage system) and used to heat the high-pressure air during the energy release phase, giving the air a higher work capacity. In compressed air energy storage systems, the heat energy collected during storage is often greater than the heat energy used during release, resulting in some heat energy waste within the system and reducing the electro-electric conversion efficiency of the compressed air energy storage system.

[0004] Secondly, air needs to be compressed through multiple stages to reach the storage pressure. The air temperature at the outlet of each stage compressor is relatively high (generally 180℃~195℃). After the high-temperature air absorbs heat from the heat storage system, its temperature decreases, but it still has a certain temperature (generally 65℃~70℃). A cooler is needed to further reduce the air temperature (generally 35℃~40℃). When the lower-temperature air is compressed by the next stage compressor, the power consumption of the compressor can be reduced. In this process, the cooler requires additional investment costs, and the heat dissipated by the air through the cooler also increases the system's energy loss and reduces the electro-electric conversion efficiency of the compressed air energy storage system.

[0005] Furthermore, thermal energy storage systems typically use pressurized water as the working fluid. The system incorporates hot and cold water tanks to achieve a cycle of heat storage and release. The temperature of the hot water tank (high temperature) depends on the air temperature at the compressor outlet, while the temperature of the cold water tank (low temperature) depends on the air temperature at the expander outlet. To increase the heat utilization during the energy release process, the expander outlet temperature needs to be lowered. However, a decrease in the expander outlet temperature will also lower the corresponding cold water tank temperature. During heat storage, a larger temperature difference between the hot and cold water tanks means more heat will be stored. Clearly, simply adjusting the structural parameters of the compressed air energy storage system itself is insufficient to fully utilize the generated heat energy, resulting in energy waste. Summary of the Invention

[0006] To address the shortcomings of existing compressed air energy storage systems, this invention provides a compressed air energy storage system coupled with an ultra-high temperature heat pump. By coupling the heat pump module, the use of the cooler in the original compressed air energy storage system can be reduced or even eliminated, and the surplus heat energy can be fully utilized. Furthermore, after the high-temperature heat exchange medium is used by the heat pump module, the return parameters can meet the heat storage and release cycle conditions of the heat storage module, thereby improving the overall system's electro-electric conversion efficiency.

[0007] The technical solution provided by this invention is: a compressed air energy storage system coupled with an ultra-high temperature heat pump, comprising an air compression module, an air storage section, an air expansion module, a first heat exchange module, a second heat exchange module, a heat storage module, a heat pump module, and a molten salt energy storage module; the air compression module is used to generate compressed air and store it in the air storage section; the air inlet of the air expansion module is connected to the outlet of the air storage section to generate electricity using compressed air; the heat storage module includes a high-temperature storage tank and a low-temperature storage tank, and the heat storage module is configured such that: the heat exchange medium flowing out of the low-temperature storage tank absorbs the heat of the compressed air through the first heat exchange module and flows into the high-temperature storage tank, and part of the heat exchange medium... The heat pump module includes a heat pump expander, a heat pump compressor, a first heat pump heat exchanger, and a second heat pump heat exchanger. The heat pump module is configured such that: part of the heat exchange medium flows out of the high-temperature storage tank to heat the air entering the heat pump compressor through the first heat pump heat exchanger, and then flows back to the low-temperature storage tank; at the same time, the compressed air generated by the heat pump compressor exchanges heat energy with molten salt through the second heat pump heat exchanger and stores the molten salt in the molten salt energy storage module; the compressed air that has passed through the second heat pump heat exchanger then flows into the heat pump expander to generate electricity.

[0008] Optionally, the first heat pump heat exchanger includes a first heat pump working fluid channel and a first heat pump gas channel for heat exchange; the inlet of the first heat pump working fluid channel is connected to the outlet of the high-temperature storage tank, and the outlet of the first heat pump working fluid channel is connected to the inlet of the low-temperature storage tank; the inlet of the first heat pump gas channel is connected to the outlet of the heat pump expander, and the outlet of the first heat pump gas channel is connected to the inlet of the heat pump compressor; the second heat pump heat exchanger includes a second heat pump working fluid channel and a second heat pump gas channel for heat exchange; the inlet and outlet of the second heat pump working fluid channel are connected to the molten salt energy storage module, the inlet of the second heat pump gas channel is connected to the outlet of the heat pump compressor, and the outlet of the second heat pump gas channel is connected to the inlet of the heat pump expander.

[0009] Optionally, it further includes a regenerator, which includes a first gas regenerator channel and a second gas regenerator channel for heat exchange; the outlet of the first heat pump gas channel is connected to the inlet of the heat pump compressor through the first gas regenerator channel; the outlet of the second heat pump gas channel is connected to the inlet of the heat pump expander through the second gas regenerator channel.

[0010] Optionally, the heat pump expander and the heat pump compressor are coaxially configured.

[0011] Optionally, the molten salt energy storage module includes a cold salt tank, a hot salt tank, and a molten salt heat exchanger. The outlet of the cold salt tank is connected to the inlet of the hot salt tank through the second heat pump heat exchanger, and the outlet of the hot salt tank is connected to the inlet of the cold salt tank through the molten salt heat exchanger. The molten salt energy storage module is configured such that: during heat storage, the low-temperature molten salt in the cold salt tank flows through the second heat pump heat exchanger to absorb heat and increase its temperature before flowing into the hot salt tank for storage; during energy release, the high-temperature molten salt in the hot salt tank flows through the molten salt heat exchanger to exchange heat with the outside and decrease its temperature before flowing into the cold salt tank for storage.

[0012] Optionally, it also includes a steam turbine generator set, the steam turbine generator set including a water vapor outlet and a steam inlet; the molten salt heat exchanger includes a molten salt channel and a steam channel for heat exchange, the outlet of the hot salt tank is connected to the inlet of the cold salt tank through the molten salt channel, and the water vapor outlet is connected to the steam inlet through the steam channel.

[0013] Optionally, the first heat exchange module includes i first heat exchangers, each containing a first working fluid channel and a first gas channel for heat exchange; the outlet of the cryogenic storage tank is connected to the inlet of the high-temperature storage tank through the first working fluid channels of the i first heat exchangers; the air compression module includes i first compressors connected in series, the inlet of the first first compressor being connected to the external environment; for adjacent first compressors, the outlet of the preceding first compressor and the inlet of the following first compressor are connected through the first gas channel on the first heat exchanger located between them; the outlet of the i-th first compressor is connected to the gas storage unit through the first gas channel on the i-th first heat exchanger. The inlet of the first heat exchange module is connected to the second heat exchanger; the second heat exchanger includes j second heat exchangers, each containing a second working fluid channel and a second gas channel for heat exchange; the outlet of the high-temperature storage tank is connected to the inlet of the low-temperature storage tank through the second working fluid channels of the j second heat exchangers; the air expansion module includes j first expanders connected in series, the air inlet of the first expander is connected to the outlet of the gas storage unit through the second gas channel on the first second heat exchanger; for adjacent first expanders, the air outlet of the preceding first expander and the air inlet of the following first expander are connected through the second gas channel on the second heat exchanger located between them; where i and j are both integers greater than or equal to 2.

[0014] Optionally, i of the first compressors are coaxially configured.

[0015] Optionally, j of the first expanders are coaxially configured.

[0016] Optionally, a cooler is provided between the first gas passage on the i-th first heat exchanger and the inlet of the gas storage section.

[0017] Compared with the prior art, the technical solution provided by this invention has the following beneficial effects: In view of the defects of existing compressed air energy storage systems, this invention can reduce or even eliminate the use of the cooler in the original compressed air energy storage system by coupling a heat pump module, and make full use of the surplus heat energy. Moreover, after the high-temperature heat exchange medium is used by the heat pump module, the return parameters can meet the heat storage and heat release cycle conditions of the heat storage module, thereby improving the overall system's electro-electric conversion efficiency.

[0018] Furthermore, the number of stages in the air expansion module can be reduced, and the heat pump module can absorb excess heat energy, thereby lowering the temperature of the return cold water in the cold water tank. During the air compression process, the cold water at a lower temperature can cool the high-temperature, high-pressure air to a lower temperature, thus eliminating the need for a cooler and enabling the system to store more heat.

[0019] The excess heat energy generated by this system can be fully absorbed and utilized by the heat pump module to a large extent, increasing the overall electro-electric conversion efficiency to over 69%. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the compressed air energy storage system coupled with an ultra-high temperature heat pump proposed in an embodiment of the present invention. Detailed Implementation

[0021] To further understand the content of this invention, a detailed description of the invention will be provided in conjunction with the accompanying drawings and embodiments.

[0022] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings. The terms "first," "second," etc., used in this invention are for the convenience of describing the technical solutions of the invention and have no specific limiting effect; they are all general terms and do not constitute a limitation on the technical solutions of the invention. It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of this application can be combined with each other. In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, not to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. Multiple technical solutions in the same embodiment, as well as multiple technical solutions in different embodiments, can be arranged and combined to form new technical solutions that do not contradict or conflict, all of which are within the scope of protection claimed by this invention.

[0023] Example 1 Combined with appendix Figure 1This embodiment of a compressed air energy storage system coupled with an ultra-high temperature heat pump includes an air compression module 1, an air storage section 2, an air expansion module 3, a first heat exchange module 4, a second heat exchange module 5, a heat storage module 6, a heat pump module 7, and a molten salt energy storage module 8. Preferably, in this embodiment, the air storage section 2 is an artificial chamber.

[0024] The air compression module 1 generates compressed air and stores it in the air storage section 2. The air expansion module 3 has its inlet connected to the outlet of the air storage section 2 to generate electricity using the compressed air.

[0025] Preferably, the first heat exchange module 4 includes i first heat exchangers 40, each first heat exchanger 40 containing a first working fluid channel and a first gas channel for heat exchange; the outlet of the cryogenic storage tank 62 is connected to the inlet of the high-temperature storage tank 61 through the first working fluid channels of the i first heat exchangers 40.

[0026] The air compression module 1 includes i first compressors 10 connected in series. The air inlet of the first first compressor 10 is connected to the external environment. For adjacent first compressors 10, the air outlet of the preceding first compressor 10 and the air inlet of the following first compressor 10 are connected through a first gas passage on a first heat exchanger 40 located between them. The air outlet of the i-th first compressor 10 is connected to the inlet of the air storage unit 2 through the first gas passage on the i-th first heat exchanger 40. Here, i is an integer greater than or equal to 2. The value of i can be adjusted according to actual conditions; in this embodiment, i is taken as 4.

[0027] In this embodiment, the air compression module 1 is used to generate high-temperature and high-pressure air. In a further embodiment, the plurality of first compressors 10 in the air compression module 1 can be coaxially configured, thereby improving the efficiency of producing high-temperature and high-pressure air.

[0028] The second heat exchange module 5 includes j second heat exchangers 50, each containing a second working fluid channel and a second gas channel for heat exchange; the outlet of the high-temperature storage tank 61 is connected to the inlet of the low-temperature storage tank 62 through the second working fluid channels of the j second heat exchangers 50.

[0029] The air expansion module 3 includes j first expanders 30 connected in series. The air inlet of the first expander is connected to the outlet of the air storage section 2 through a second gas channel on the first second heat exchanger 50. For adjacent first expanders 30, the air outlet of the preceding first expander 30 and the air inlet of the following first expander 30 are connected through a second gas channel on the second heat exchanger 50 located between them. Here, j is an integer greater than or equal to 2. The value of j can be adjusted according to actual conditions; in this embodiment, j is taken as 4.

[0030] In this embodiment, the output of the air expansion module 3 is generally connected to the generator set to generate electricity by using compressed air. The multiple first expanders 30 in the air expansion module 3 can be coaxially configured, thereby improving the power generation efficiency.

[0031] The heat storage module 6 includes a high-temperature storage tank 61 and a low-temperature storage tank 62. The heat storage module 6 is configured such that the heat exchange medium flowing out of the low-temperature storage tank 62 absorbs heat from the compressed air through the first heat exchange module 4 and flows into the high-temperature storage tank 61. Part of the heat exchange medium flows out of the high-temperature storage tank 61 to heat the compressed air entering the air expansion module 3 through the second heat exchange module 5, and then flows back to the low-temperature storage tank 62. Generally, the heat exchange medium is water; the high-temperature storage tank 61 stores relatively hot water at a relatively high temperature, and the low-temperature storage tank 62 stores relatively cold water at a relatively low temperature.

[0032] The heat pump module 7 includes a heat pump expander 73, a heat pump compressor 74, a first heat pump heat exchanger 71, and a second heat pump heat exchanger 72. The heat pump module 7 is configured such that: a portion of the heat exchange working fluid flows out from the high-temperature storage tank 61 to heat the air entering the heat pump compressor 74 via the first heat pump heat exchanger 71, and then flows back to the low-temperature storage tank 62; simultaneously, the compressed air generated by the heat pump compressor 74 exchanges heat energy with molten salt via the second heat pump heat exchanger 72 and stores the molten salt in the molten salt energy storage module 8; the compressed air passing through the second heat pump heat exchanger 72 then flows back into the heat pump expander 73 to generate electricity. In this embodiment, the heat pump module 7 constitutes an ultra-high temperature heat pump. In this art, ultra-high temperature refers to the compressor outlet working fluid temperature reaching 550℃~610℃, which corresponds to the outlet working fluid temperature of the heat pump compressor 74 in this embodiment reaching 550℃~610℃.

[0033] The compressed air energy storage system of the coupled ultra-high temperature heat pump in this embodiment includes an energy storage process and an energy release process.

[0034] The energy storage process is as follows: First, ambient air is compressed by the air compression module 1, and the resulting heat energy (temperature approximately 193°C) is absorbed by relatively cool water flowing out of the low-temperature storage tank 62 in the heat storage module 6. The cool water is heated to a relatively high temperature, becoming hot water. The hot water then flows back to the high-temperature storage tank 61, thus storing the heat energy in the high-temperature storage tank 61. Meanwhile, the high-pressure air compressed by the compression module is stored in the air storage section 2 (i.e., the artificial chamber).

[0035] Then, a portion of water (the surplus after satisfying the heat energy required by the air expansion module 3) is extracted from the high-temperature storage tank 61 of the heat storage module 6 and supplied to the heat pump module 7 as a low-temperature heat source (temperature about 193°C). The heat pump module 7 absorbs the heat energy from the low-temperature heat source (and, in conjunction with the input of additional electrical energy) to produce high-temperature heat energy (temperature about 565°C) and stores the heat energy in the molten salt energy storage module 8.

[0036] In heat pump module 7, the heat pump working fluid (generally air) absorbs heat from a low-temperature heat source (in this embodiment, the low-temperature heat source is hot water in the high-temperature storage tank 61 of the heat storage module 6) through the first heat pump heat exchanger 71. It then enters the heat pump compressor 74, where it is compressed and raised to a higher temperature. The heat energy of the working fluid is then transferred to the molten salt through the second heat pump heat exchanger 72. The low-temperature molten salt in the molten salt energy storage module 8 is thus heated to a high temperature and stored. After releasing heat energy in the second heat pump heat exchanger 72, the working fluid's temperature decreases. It then enters the heat pump expander 73 to release the pressure energy of the working fluid, transforming it into a low-temperature, low-pressure fluid, thus forming a cycle.

[0037] Subsequently, the hot water drawn from the high-temperature storage tank 61 is cooled after passing through the heat pump module 7, and then the cold water flows into the low-temperature storage tank 62.

[0038] Specifically, for heat pump module 7, its preferred structural form is as follows: The first heat pump heat exchanger 71 includes a first heat pump working fluid channel and a first heat pump gas channel for heat exchange. The inlet of the first heat pump working fluid channel is connected to the outlet of the high-temperature storage tank 61, and the outlet of the first heat pump working fluid channel is connected to the inlet of the low-temperature storage tank 62. The inlet of the first heat pump gas channel is connected to the outlet of the heat pump expander 73, and the outlet of the first heat pump gas channel is connected to the inlet of the heat pump compressor 74. The second heat pump heat exchanger 72 includes a second heat pump working fluid channel and a second heat pump gas channel for heat exchange. The inlet and outlet of the second heat pump working fluid channel are connected to the molten salt energy storage module 8, the inlet of the second heat pump gas channel is connected to the outlet of the heat pump compressor 74, and the outlet of the second heat pump gas channel is connected to the inlet of the heat pump expander 73. Based on this structural form of heat pump module 7, the aforementioned energy storage process can be realized.

[0039] Furthermore, in a preferred embodiment, the heat pump expander 73 and the heat pump compressor 74 are coaxially configured, thereby the work done by the pressure energy of the heat pump working fluid after entering the heat pump expander 73 can compensate for the power consumption of the coaxial heat pump compressor 74.

[0040] In another preferred embodiment, a regenerator 91 may be provided, comprising a first gas regenerator channel and a second gas regenerator channel for heat exchange. The outlet of the first heat pump gas channel is connected to the inlet of the heat pump compressor 74 via the first gas regenerator channel; the outlet of the second heat pump gas channel is connected to the inlet of the heat pump expander 73 via the second gas regenerator channel. Based on the regenerator 91, for the heat pump module 7, after the heat pump working fluid releases heat energy in the second heat pump heat exchanger 72, it can pass through the regenerator 91, and the regenerator 91 can recover and utilize the waste heat. That is, when air with waste heat flows through the second gas regenerator channel, it can heat the heat pump working fluid flowing through the first gas regenerator channel, further increasing the temperature of the heat pump working fluid entering the heat pump compressor 74, thereby raising the temperature of the heat pump working fluid after compression by the heat pump compressor 74.

[0041] In a preferred embodiment, the molten salt energy storage module 8 of this example has the following structure: it includes a cold salt tank 81, a hot salt tank 82, and a molten salt heat exchanger 83. The outlet of the cold salt tank 81 is connected to the inlet of the hot salt tank 82 via a second heat pump heat exchanger 72, and the outlet of the hot salt tank 82 is connected to the inlet of the cold salt tank 81 via the molten salt heat exchanger 83. The molten salt energy storage module 8 is configured such that during heat storage, the low-temperature molten salt in the cold salt tank 81 flows through the second heat pump heat exchanger 72 to absorb heat and increase its temperature before flowing into the hot salt tank 82 for storage; during energy release, the high-temperature molten salt in the hot salt tank 82 flows through the molten salt heat exchanger 83 to exchange heat with the outside and decrease its temperature before flowing into the cold salt tank 81 for storage. Based on this structural form of the molten salt energy storage module 8, the aforementioned energy storage process can be realized.

[0042] For the compressed air energy storage system of the coupled ultra-high temperature heat pump in this embodiment, another working process is the energy release process, which is described in detail below: High-pressure air expands in air expansion module 3 to generate electricity. Before entering air expansion module 3, the high-pressure air exchanges heat with hot water flowing out of high-temperature storage tank 61 in heat storage module 6. After absorbing heat energy, the air heats up (to about 183°C), thereby improving the air's work capacity. At the same time, the hot water becomes cold water (temperature about 35°C) after heat exchange and is stored in low-temperature storage tank 62.

[0043] Because of the presence of the heat pump module 7, a portion of the thermal energy in the heat storage module 6 can be stored and utilized. Therefore, the number of first expanders 30 in the air expansion module 3 can be relatively small. Under the condition that the total expansion ratio remains unchanged, the pressure drop borne by each first expander 30 can be increased. As a result, the outlet temperature of the first expander 30 is reduced (to about 20°C), which makes the temperature of the cold water after the hot water heat exchange even lower, that is, the temperature of the low-temperature storage tank 62 is reduced.

[0044] Therefore, after the temperature of the low-temperature storage tank 62 in the thermal storage module 6 decreases, the thermal storage module 6 can cool the high-temperature and high-pressure air to a lower temperature (about 50°C) during the air compression process. Thus, compared with the traditional compressed air energy storage system, most of the coolers 93 can be eliminated.

[0045] Furthermore, it may also include a steam turbine generator set 92, which includes a steam outlet and a steam inlet; a molten salt heat exchanger 83 includes a molten salt channel and a steam channel for heat exchange, the outlet of the hot salt tank 82 is connected to the inlet of the cold salt tank 81 through the molten salt channel, and the steam outlet is connected to the steam inlet through the steam channel. Thus, the molten salt energy storage module 8 heats the feedwater into steam through the molten salt heat exchanger 83, and the steam generates electricity by passing through the steam turbine generator set 92.

[0046] Furthermore, in a preferred embodiment, a cooler 93 is provided between the first gas passage on the i-th first heat exchanger 40 (i.e., the first heat exchanger 40 directly adjacent to the gas storage section 2) and the inlet of the gas storage section 2. This cooler 93 reduces the air temperature output from the air compression module 1 to the gas storage section 2, ensuring that the air temperature entering the gas storage section 2 remains below a threshold, thus providing a certain degree of protection.

[0047] In summary, compared to existing compressed air energy storage systems, the compressed air energy storage system coupled with an ultra-high temperature heat pump in this embodiment can eliminate the need for a cooler in the original compressed air energy storage system by using the coupled heat pump module 7, and fully utilize the surplus heat energy. Furthermore, after the high-temperature heat exchange medium is used by the heat pump module 7, the return parameters can meet the cycle conditions for heat storage and release of the heat storage module 6, thereby improving the overall system's electro-electric conversion efficiency.

[0048] Furthermore, the number of stages in the air expansion module 3 can be reduced, and the heat pump module 7 can absorb excess heat energy, thereby lowering the temperature of the return cold water in the cold water tank. During the air compression process, the cold water at a lower temperature can cool the high-temperature, high-pressure air to a lower temperature, thus eliminating the need for the cooler 93 and enabling the system to store more heat.

[0049] The excess heat generated by this system can be fully absorbed and utilized by the heat pump module 7 to a great extent. After the excess heat is supplied to the heat pump module 7, the heat storage module 6 can form a cycle, and the overall electro-electric conversion efficiency is increased to more than 69%.

[0050] The present invention and its embodiments have been described above illustratively. This description is not restrictive, and the figures shown are only one embodiment of the present invention; the actual structure is not limited thereto. Therefore, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the invention, such designs should fall within the protection scope of the present invention.

Claims

1. A compressed air energy storage system coupled with an ultra-high temperature heat pump, characterized in that, It includes an air compression module (1), an air storage unit (2), an air expansion module (3), a first heat exchange module (4), a second heat exchange module (5), a heat storage module (6), a heat pump module (7), and a molten salt energy storage module (8); The air compression module (1) is used to generate compressed air and store the compressed air in the air storage unit (2); The air inlet of the air expansion module (3) is connected to the outlet of the air storage unit (2) to generate electricity using compressed air; The heat storage module (6) includes a high-temperature storage tank (61) and a low-temperature storage tank (62). The heat storage module (6) is configured such that: the heat exchange medium flowing out of the low-temperature storage tank (62) absorbs the heat of the compressed air through the first heat exchange module (4) and flows into the high-temperature storage tank (61); part of the heat exchange medium flows out of the high-temperature storage tank (61) to heat the compressed air entering the air expansion module (3) through the second heat exchange module (5) and then flows back to the low-temperature storage tank (62); The heat pump module (7) includes a heat pump expander (73), a heat pump compressor (74), a first heat pump heat exchanger (71), and a second heat pump heat exchanger (72). The heat pump module (7) is configured such that: part of the heat exchange working fluid flows out from the high-temperature storage tank (61) to heat the air entering the heat pump compressor (74) through the first heat pump heat exchanger (71), and then flows back to the low-temperature storage tank (62); at the same time, the compressed air generated by the heat pump compressor (74) exchanges heat energy with molten salt through the second heat pump heat exchanger (72) and stores the molten salt in the molten salt energy storage module (8); the compressed air passing through the second heat pump heat exchanger (72) then flows into the heat pump expander (73) to generate electricity.

2. The compressed air energy storage system coupled with an ultra-high temperature heat pump according to claim 1, characterized in that, The first heat pump heat exchanger (71) includes a first heat pump working fluid channel and a first heat pump gas channel for heat exchange; the inlet of the first heat pump working fluid channel is connected to the outlet of the high-temperature storage tank (61), and the outlet of the first heat pump working fluid channel is connected to the inlet of the low-temperature storage tank (62); the inlet of the first heat pump gas channel is connected to the outlet of the heat pump expander (73), and the outlet of the first heat pump gas channel is connected to the inlet of the heat pump compressor (74). The second heat pump heat exchanger (72) includes a second heat pump working fluid channel and a second heat pump gas channel for heat exchange; the inlet and outlet of the second heat pump working fluid channel are connected to the molten salt energy storage module (8), the inlet of the second heat pump gas channel is connected to the outlet of the heat pump compressor (74), and the outlet of the second heat pump gas channel is connected to the inlet of the heat pump expander (73).

3. The compressed air energy storage system coupled with an ultra-high temperature heat pump according to claim 2, characterized in that, It also includes a regenerator (91), which includes a first gas regenerator channel and a second gas regenerator channel for heat exchange; the outlet of the first heat pump gas channel is connected to the inlet of the heat pump compressor (74) through the first gas regenerator channel; the outlet of the second heat pump gas channel is connected to the inlet of the heat pump expander (73) through the second gas regenerator channel.

4. A compressed air energy storage system coupled with an ultra-high temperature heat pump according to any one of claims 1-3, characterized in that, The heat pump expander (73) and the heat pump compressor (74) are coaxially configured.

5. The compressed air energy storage system coupled with an ultra-high temperature heat pump according to claim 1, characterized in that, The molten salt energy storage module (8) includes a cold salt tank (81), a hot salt tank (82), and a molten salt heat exchanger (83). The outlet of the cold salt tank (81) is connected to the inlet of the hot salt tank (82) through the second heat pump heat exchanger (72), and the outlet of the hot salt tank (82) is connected to the inlet of the cold salt tank (81) through the molten salt heat exchanger (83). The molten salt energy storage module (8) is configured such that: during heat storage, the low-temperature molten salt in the cold salt tank (81) flows through the second heat pump heat exchanger (72) to absorb heat and increase its temperature before flowing into the hot salt tank (82) for storage; during energy release, the high-temperature molten salt in the hot salt tank (82) flows through the molten salt heat exchanger (83) to exchange heat with the outside and decrease its temperature before flowing into the cold salt tank (81) for storage.

6. The compressed air energy storage system coupled with an ultra-high temperature heat pump according to claim 5, characterized in that, It also includes a steam turbine generator set (92), which includes a steam outlet and a steam inlet; the molten salt heat exchanger (83) includes a molten salt channel and a steam channel for heat exchange, the outlet of the hot salt tank (82) is connected to the inlet of the cold salt tank (81) through the molten salt channel, and the steam outlet is connected to the steam inlet through the steam channel.

7. The compressed air energy storage system coupled with an ultra-high temperature heat pump according to claim 1, characterized in that, The first heat exchange module (4) includes i first heat exchangers (40), each of which contains a first working fluid channel and a first gas channel for heat exchange; the outlet of the low-temperature storage tank (62) is connected to the inlet of the high-temperature storage tank (61) through the first working fluid channels of the i first heat exchangers (40); The air compression module (1) includes i first compressors (10) connected in series. The air inlet of the first first compressor (10) is connected to the external environment. For adjacent first compressors (10), the air outlet of the previous first compressor (10) and the air inlet of the next first compressor (10) are connected through the first gas passage on the first heat exchanger (40) located between them. The air outlet of the i-th first compressor (10) is connected to the inlet of the gas storage unit (2) through the first gas passage on the i-th first heat exchanger (40). The second heat exchange module (5) includes j second heat exchangers (50), each second heat exchanger (50) containing a second working fluid channel and a second gas channel for heat exchange; the outlet of the high-temperature storage tank (61) is connected to the inlet of the low-temperature storage tank (62) through the second working fluid channels of the j second heat exchangers (50); The air expansion module (3) includes j first expanders (30) connected in series. The air inlet of the first expander is connected to the outlet of the gas storage unit (2) through the second gas channel on the first second heat exchanger (50). For adjacent first expanders (30), the air outlet of the previous first expander (30) and the air inlet of the next first expander (30) are connected through the second gas channel on the second heat exchanger (50) located between them. Where i and j are both integers greater than or equal to 2.

8. The compressed air energy storage system coupled with an ultra-high temperature heat pump according to claim 7, characterized in that, i of the first compressors (10) are coaxially configured.

9. A compressed air energy storage system coupled with an ultra-high temperature heat pump according to claim 7, characterized in that, j of the first expanders (30) are coaxially configured.

10. A compressed air energy storage system coupled with an ultra-high temperature heat pump according to claim 7, characterized in that, A cooler (93) is provided between the first gas passage on the i-th first heat exchanger (40) and the inlet of the gas storage section (2).

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