Multi-energy storage system and method

Abstract

The invention provides a multi-energy storage system which comprises a temperature adjusting assembly, a compression network, a regenerator, a working medium gas preparation network and a switching loop. The cold side of the regenerator is connected with a natural gas pipeline and a working medium gas preparation network; the working medium gas preparation network outputs working medium gas through acting of the first turbine; and the switching loop shunts and mixes working medium gas output by the compression network and working medium gas output by the working medium gas preparation network through a fourth temperature adjusting device and a fifth temperature adjusting device, so that the compression network and the working medium gas preparation network form an annular loop for sufficient heat exchange. According to the invention, by designing the circulating connection loop among the multistage temperature adjusting devices, the working medium gas circularly flows between the cold side and the hot side of each stage of temperature adjusting device after being shunted and converged, so that on one hand, the heat exchange temperature difference of two fluids is reduced, and on the other hand, the flow of the fluids in a special area is increased; therefore, the pinch point problem is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of compressed gas energy storage, and in particular relates to a multi-energy storage system and method. Background Art

[0002] In the development of energy storage technology, compressed gas energy storage technology occupies an important position. At present, most compressed gas energy storage technologies use air as the working fluid. Due to the low density of air itself, the thermal parameters required for compressed air are higher, which leads to a larger equipment volume for the entire system, especially the gas storage device. This situation leads to a lower energy density for the entire system. Although there is liquefied compressed air energy storage technology, which can greatly reduce the volume of the gas storage device, the critical temperature of air is as low as -140.5℃. Such a low critical temperature causes a large loss of effective cooling energy in the system, which reduces the efficiency and performance of the overall system. At the same time, low temperature conditions pose severe challenges to energy storage materials.

[0003] Compared with air, carbon dioxide as a working fluid has easier critical conditions to reach, with a critical temperature of 30.98°C and a critical pressure of 7.38MPa. This characteristic makes carbon dioxide easier to liquefy. In addition, in the compressed carbon dioxide system, the working fluid is mostly in a transcritical or supercritical state, and the working fluid density is high at this time, which makes the equipment size of the compressed carbon dioxide system very compact and the energy density of the system can be greatly improved.

[0004] However, most of the current compressed carbon dioxide energy storage systems are adiabatic systems, without external heat sources to provide heat for them, which results in a low turbine inlet temperature and a low power output of the overall system. In addition, since the specific heat capacity of carbon dioxide changes drastically near the critical point, there is a large heat capacity difference between the high-pressure side and the low-pressure side working fluid in the compressed carbon dioxide energy storage system, which will cause a "pinch point" problem during the heat recovery process, which will deteriorate the heat transfer and thus limit the improvement of the cycle efficiency. Summary of the invention

[0005] In order to solve the problem of low turbine inlet temperature and pinch point during heat recovery of the compressed carbon dioxide energy storage system described in the background technology, the present invention proposes the following technical solution:

[0006] A multi-energy storage system comprises: a temperature regulating component, a compression network, a cold storage device, a working fluid gas preparation network and a switching circuit; the cold side of the first temperature regulating device is connected to the cold side of the fourth temperature regulating device, and flows back to the hot side of the first temperature regulating device through the cold side of the second temperature regulating device; the hot side of the second temperature regulating device is connected to the hot side of the first turbine and the fifth temperature regulating device; the third temperature regulating device is used to change the physical state of the working fluid in the compression network; the cold side of the fourth temperature regulating device is connected to the output end of the compression network, and the hot side of the fourth temperature regulating device is connected to the input end of the compression network through the hot side of the cold storage device; the cold side of the cold storage device is connected to the natural gas pipeline and the working fluid gas preparation network; the working fluid gas preparation network outputs working fluid gas through the first turbine doing work; the switching circuit divides and mixes the working fluid gas output from the compression network and the working fluid gas output from the working fluid gas preparation network through the fourth temperature regulating device and the fifth temperature regulating device, so that the compression network and the working fluid gas preparation network form a ring loop with sufficient heat exchange.

[0007] Among them, the compression network includes: a low-pressure working fluid gas storage tank, a booster pump, a first compressor and a high-pressure working fluid gas storage tank; the output end of the low-pressure working fluid gas storage tank outputs liquid working fluid to the cold side of the third temperature control device through the booster pump; the third temperature control device is used to heat and evaporate the liquid working fluid, and output the working fluid gas to the first compressor; the first compressor is used to pressurize the working fluid gas and store it in the high-pressure working fluid gas storage tank after passing through the cold side of the third temperature control device, so as to provide high-pressure working fluid gas for the switching circuit.

[0008] Furthermore, the switching circuit includes: a first condenser, a separator and a second compressor; one end of the cold side of the fourth temperature control device is connected to the output end of the high-pressure working fluid gas storage tank through a first three-way joint A, and the other end of the cold side of the fourth temperature control device is connected to the cold side of the first temperature control device through a second three-way joint B, and then connected to the second turbine through the cold side of the second temperature control device; the second compressor and the hot side of the first temperature control device are connected to the hot side of the fourth temperature control device through a third three-way joint C; the first condenser receives the working fluid gas input from the hot side of the second temperature control device through the hot side of the fifth temperature control device to condense the working fluid gas output from the working fluid gas preparation network; the separator is used to separate the working fluid gas and liquid water condensed by the first condenser; the second compressor is used to compress the working fluid gas output by the separator, and output it to one end of the hot side of the fourth temperature control device through the third three-way joint C.

[0009] Furthermore, the working gas preparation network includes: an electrolyzer, an oxygen storage tank, a hydrogen storage tank and a combustion chamber; the electrolyzer is used to electrolyze water and store the generated oxygen and hydrogen in the oxygen storage tank and the hydrogen storage tank respectively, and the combustion chamber is used to connect the oxygen storage tank and the natural gas pipeline to output the generated working gas to the first turbine by burning natural gas.

[0010] Furthermore, the multi-energy storage system also includes a methanol preparation loop, and the temperature control component also includes a sixth temperature control device; the methanol preparation loop includes: a methanol synthesizer, a methanol separator, a mixer and a third compressor; the methanol synthesizer is connected to the cold side of the sixth temperature control device and the hot side of the sixth temperature control device to output the synthesis product to the methanol separator; the methanol synthesizer and the mixer are connected through the sixth temperature control device; one side of the mixer is connected to the third compressor and receives the working fluid gas output by the fourth temperature control device through a fourth three-way joint D to output the mixed gas to the cold side of the sixth temperature control device; the third compressor is used to compress the hydrogen output by the hydrogen storage tank to output high-pressure hydrogen to the mixer.

[0011] Furthermore, the output end of the natural gas pipeline supplies gas to the combustion chamber and the end user respectively after passing through the third turbine and the cold side of the cold storage device.

[0012] Furthermore, the cold-side output flow rate of the first temperature regulating device is equal to the hot-side output flow rate of the fourth temperature regulating device.

[0013] Furthermore, the pressure of the working gas output by the second compressor is equal to the pressure of the working gas output by the first temperature regulating device.

[0014] Another object of the present invention is to propose a multi-energy storage method applied to the above-mentioned multi-energy storage system, comprising: connecting the compression network, the cold storage device, the working fluid gas preparation network and the switching circuit through the temperature control component to form a heat exchange circuit; when the working fluid circulates in the heat exchange circuit, the working fluid gas output by the working fluid gas preparation network energizes the heat exchange circuit through the first turbine; the natural gas pipeline is coupled to the heat exchange circuit through the cold storage device, and the natural gas output by the natural gas pipeline energizes the heat exchange circuit after the combustion reaction; the cold storage device absorbs energy from the heat exchange circuit and changes the physical state of the working fluid flowing into the compression network, and the compression network changes the physical state of the working fluid and stores the energy transferred from the low-pressure side of the heat exchange circuit; the switching circuit diverts and mixes the working fluid gas output from the high-pressure side of the heat exchange circuit and the working fluid gas output from the low-pressure side of the heat exchange circuit, thereby reducing the temperature difference between the hot side and the cold side in each of the temperature control components during the heat recovery process.

[0015] Furthermore, the low-pressure working fluid gas flowing out of the switching circuit enters the compression network and the methanol preparation network respectively, thereby storing the energy transferred by the low-pressure side of the heat exchange.

[0016] Beneficial effects: The present invention designs a circulating connection loop between multiple levels of temperature control devices, so that the working gas circulates between the cold side and the hot side of each level of temperature control device after diversion and confluence, thereby reducing the temperature difference between the two fluids on the one hand, and increasing the flow rate of the fluid in a specific area on the other hand, thereby solving the pinch point problem. In addition, the present invention provides an external heat source for the compressed carbon dioxide energy storage system through the working gas preparation network, thereby increasing the inlet temperature of the turbine of the compressed carbon dioxide energy storage system to increase the power output of the system, and the carbon dioxide gas generated by combustion can be recycled. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the structure of a multi-energy storage system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solution and advantages of the present application clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0019] It should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing this patent and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this patent.

[0020] Figure 1 Schematic diagram of the structure of a multi-energy storage system according to an embodiment of the present invention.

[0021] Reference Figure 1, a multi-energy storage system according to an embodiment of the present invention includes: a temperature regulating component 1, a compression network 2, a cold storage device 3, a working fluid gas preparation network 4 and a switching circuit 5. The cold side of the first temperature regulating device 11 is connected to the cold side of the fourth temperature regulating device 14, and flows back to the hot side of the first temperature regulating device 11 through the cold side of the second temperature regulating device 12. The hot side of the second temperature regulating device 12 is connected to the hot side of the first turbine 6 and the fifth temperature regulating device 15. The third temperature regulating device 13 is used to change the physical state of the working fluid in the compression network 2. The cold side of the fourth temperature regulating device 14 is connected to the output end of the compression network 2, and the hot side of the fourth temperature regulating device 14 is connected to the input end of the compression network 2 through the hot side of the cold storage device 3. The cold side of the cold storage device 3 is connected to the natural gas pipeline 7 and the working fluid gas preparation network 4. The working fluid gas preparation network 4 outputs the working fluid gas through the first turbine 6 doing work. The switching circuit 5 divides and mixes the working gas output from the compression network 2 and the working gas output from the working gas preparation network 4 through the fourth temperature regulating device 14 and the fifth temperature regulating device 15, so that the compression network 2 and the working gas preparation network 4 form a ring circuit for sufficient heat exchange. Furthermore, the flow rate output from the cold side of the first temperature regulating device 11 is equal to the output flow rate from the hot side of the fourth temperature regulating device 14.

[0022] Specifically, the compression network 2 includes a low-pressure working fluid gas storage tank 21, a booster pump 22, a first compressor 23 and a high-pressure working fluid gas storage tank 24. The input end of the low-pressure working fluid gas storage tank 21 is connected to the hot side of the cold storage device 3, and the output end of the low-pressure working fluid gas storage tank 21 outputs liquid working fluid to the cold side of the third temperature regulating device 13 through the booster pump 22. Inside the third temperature regulating device 13, the liquid working fluid absorbs heat from the hot side of the third temperature regulating device 13, thereby vaporizing to form a low-pressure working fluid gas. The two ends of the first compressor 23 are respectively connected to the cold side of the third temperature regulating device 13 and the hot side of the third temperature regulating device 13, thereby converting the low-pressure working fluid gas into a high-pressure working fluid gas and storing it in the high-pressure gas storage tank 24. Furthermore, before the low-pressure working fluid gas enters the high-pressure gas storage tank 24, it needs to be cooled by the cooling device 25, which, on the one hand, increases the capacity of the high-pressure gas storage tank 24, and on the other hand, prevents the working fluid gas from entering the high-pressure gas storage tank 24 due to excessive temperature and causing safety accidents.

[0023] Specifically, the switching circuit 5 includes: a first condenser 51, a separator 52, and a second compressor 53. Among them, one end of the cold side of the fourth temperature control device 14 is connected to the output end of the high-pressure working fluid gas storage tank 24 through the first three-way joint A, and the other end of the cold side of the fourth temperature control device 14 is connected to the cold side of the first temperature control device 11 and the cold side of the fifth temperature control device 15 through the second three-way joint B. The hot side of the fourth temperature control device 14 is connected to the second compressor 53 and the hot side of the second temperature control device 12. The separator 52 is used to divert the liquid water and working fluid gas condensed by the first condenser 51, so as to purify the working fluid gas. The second compressor 53 compresses the working fluid gas output by the separator 52, and after the compression is completed, it is output from one end of the hot side of the fourth temperature control device 14 to the cold storage device 3 through the third three-way joint C.

[0024] Specifically, the working gas preparation network 4 includes: an electrolyzer 41, an oxygen storage tank 42, a hydrogen storage tank 43 and a combustion chamber 44. The electrolyzer 41 is connected to an external water source and power source, and the hydrogen and oxygen generated by electrolysis provide corresponding supplies for the hydrogen storage tank 43 and the oxygen storage tank 42. The oxygen storage tank 42 is connected to the combustion chamber 44. When the natural gas transported by the natural gas pipeline 7 enters the combustion chamber 44 for combustion reaction, the output working gas expands through the first turbine 6 to do work to form a corresponding high-temperature working gas, which is then input into the hot side of the second temperature control device 12, thereby supplying heat to the cold side of the second temperature control device 12.

[0025] Specifically, the natural gas pipeline 7 is connected to the cold side of the cold storage device 3 through the third turbine 71. The cold side of the cold storage device 3 is output to the terminal customer at one end through the fifth three-way joint E, and the other end is output to the combustion chamber 44. The cold side of the cold storage device 3 absorbs the cold energy provided by the expansion and cooling of the natural gas. The hot side of the cold storage device 3 is connected to the temperature regulating component 1, so that the cold energy carried by the natural gas combustion is coupled into the circular loop of the heat exchange, and then the working gas is cooled to a liquid state to be transported to the low-pressure working gas storage tank 21.

[0026] In order to further improve the economy and energy utilization efficiency of the whole system, in this embodiment, the multi-energy storage system further includes: a methanol preparation loop 9, and the temperature control component 1 includes a sixth temperature control device 16. Among them, the methanol preparation loop 9 includes: a methanol synthesizer 91, a methanol separator 92, a mixer 93 and a third compressor 94. Among them, the cold side of the sixth temperature control device 16 is connected to the output end of the mixer 93 and the input end of the methanol synthesizer 91, and the hot side of the sixth temperature control device 16 is connected to the output end of the methanol synthesizer 91 and the input end of the methanol separator 92. One end of the input end of the mixer 93 is connected to the hot side of the fourth temperature control device 14 through a fourth three-way connector D, and the other end of the input end of the mixer 93 is connected to the third compressor 94.

[0027] In this embodiment, in the energy storage stage, the compression network 2 is connected to the cold side of the third temperature regulating device 13 and the hot side of the third temperature regulating device 13 through the first compressor 23, so as to convert the liquid working fluid into high-pressure working fluid gas and store it in the high-pressure working fluid gas storage tank 24. The working fluid gas preparation network 4 generates corresponding oxygen and hydrogen through electrolysis reaction, and stores them in the oxygen storage tank 42 and the hydrogen storage tank 43 respectively. The external natural gas supply pipeline is expanded and works through the third turbine 71 and then output to the user through the cold side of the cold storage device 3.

[0028] During the energy release stage, the high-pressure working gas stored in the high-pressure working gas storage tank 24 is split after passing through the first three-way joint A, and a part of it flows through the cold side of the fourth temperature regulating device 14 to absorb the heat of the hot side of the fourth temperature regulating device 14 and output it to the second three-way joint B; the other part of it flows into the cold side of the fifth temperature regulating device 15 to absorb the heat of the hot side of the fifth temperature regulating device 15 and then output it to the second three-way joint B. The second three-way joint B converges and mixes the working gas output from the cold side of the fifth temperature regulating device 15 and the working gas output from the cold side of the fourth temperature regulating device 14, and the mixed working gas is input to the cold side of the second temperature regulating device 12 through the cold side of the first temperature regulating device 11 to gradually absorb heat and heat up, and then input into the second turbine 8 to expand and do work.

[0029] During the energy release process, the working gas absorbs part of the heat from the hot side each time it passes through the temperature regulating component 1. The working gas that has expanded and done work through the second turbine 8 flows back to the hot side of the first temperature regulating device 11, and after flowing through the hot side of the fourth temperature regulating device 14, part of it flows into the low-pressure working gas storage tank 21 through the hot side of the cold storage device 3 to form a closed loop. In the switching circuit 5, the hot side of the fifth temperature regulating device 15 receives the high-temperature working gas generated after the expansion and work of the first turbine 6 through the hot side of the second temperature regulating device 12, thereby providing heat for the cold side of the fifth temperature regulating device 15. The working gas that flows through the hot side of the fifth temperature regulating device 15 is mixed with the working gas that flows out of the hot side of the first temperature regulating device 11 after being cooled, dehumidified and pressurized, and is output to the low-pressure working gas storage tank 21 through the hot side of the cold storage device 3. In addition, the external natural gas pipeline 7 is expanded and works through the third turbine 71, and then output through the cold side combustion chamber 44 of the cold storage device 3. The exhaust gas generated by the combustion of the natural gas is used for heat transfer to the transfer circuit 5 on the one hand, and flows into the methanol synthesizer 91 for methanol preparation on the other hand, so that the reactants of each process can be fully utilized.

[0030] Another object of the present invention is to propose a multi-energy storage method for the above-mentioned multi-energy storage system, comprising: connecting the compression network 2, the cold storage device 3, the working gas preparation network 4 and the switching circuit 5 respectively through the temperature control component 1 to construct a heat exchange circuit. When the working fluid circulates in the heat exchange circuit, the working gas output by the working gas preparation network 4 energizes the heat exchange circuit through the first turbine 6. The natural gas pipeline 7 is coupled to the heat exchange circuit through the cold storage device 3. The natural gas output by the natural gas pipeline 7 energizes the heat exchange circuit after the combustion reaction.

[0031] After the natural gas in the natural gas pipeline 7 is expanded and cooled by the third turbine 71, the cold energy generated is absorbed by the cold storage device 3. At the same time, the cold storage device 3 converts the working fluid input into the compression network 2 from gas to liquid, and stores it in the low-pressure working fluid gas storage tank 21. The working fluid in the compression network 2 will be reduced to gas by absorbing heat and evaporating from the liquid during use, and after being pressurized, it will output high-pressure working fluid gas to the transfer circuit 5. The transfer circuit 5 diverts and mixes the working fluid gas output from the high-pressure side of the heat exchange circuit and the working fluid gas from the low-pressure side of the heat exchange circuit, thereby reducing the temperature difference between the cold side and the hot side of each temperature control component 1 during the heat recovery process. The specific structures of the compression network 2, the working fluid gas preparation network 4, the transfer circuit 5, and the methanol preparation circuit 8 have been introduced in detail above and will not be repeated here.

[0032] During the energy release process, the natural gas output from the natural gas pipeline 7 and the oxygen output from the working gas preparation network 4 are mixed and burned in the combustion chamber 44, thereby generating a large amount of high-temperature working gas, which is used to supply energy to the high-pressure side of the heat exchange circuit (i.e., the compression network 2 side). In addition, before the natural gas enters the combustion chamber 44, it can also be used to perform work through the third turbine 71 to further improve the power generation efficiency of the system and increase the energy coupled into the heat exchange circuit. The working gas flowing out of the working gas preparation network 4 is still a high-temperature working gas after the first turbine 6 performs work. The working gas output from the compression network 2 is a high-pressure working gas with a lower temperature. The above two fluids are first diverted and then mixed in the transfer circuit 5, and the multi-stage temperature control 1 is designed to reduce the temperature difference between the fluids participating in the heat exchange in the temperature control component 14, thereby alleviating the internal "pinch point" problem.

[0033] Furthermore, in order to further improve the energy efficiency. In other embodiments, a portion of the low-pressure working fluid gas flowing out of the transfer circuit flows into the compression network 2 after passing through the fourth three-way connector D, and the other portion is mixed with the by-product hydrogen flowing out of the working fluid gas preparation network 4 and flows into the methanol preparation circuit 9 together, thereby converting the carbon dioxide and by-product hydrogen generated by the combustion of natural gas into high-value-added methanol products for storage.

[0034] In summary, the present invention designs a circulating connection loop between multiple stages of temperature control devices, so that the working fluid gas circulates between the cold side and the hot side of each stage of temperature control devices after diversion and convergence, thereby reducing the temperature difference between the two fluids on the one hand, and increasing the flow rate of the fluid in a specific area on the other hand, thereby solving the pinch point problem. In addition, the present invention provides an external heat source for the compressed carbon dioxide energy storage system by coupling the natural gas supply system and the water electrolysis hydrogen production system, thereby increasing the inlet temperature of the turbine of the compressed carbon dioxide energy storage system to increase the power output of the system; the carbon dioxide gas produced by combustion can be recycled and utilized, on the one hand as the working fluid of the compressed carbon dioxide energy storage system, and on the other hand to prepare methanol products with high added value, while achieving zero carbon emissions of the system, improving the efficiency and economy of the system.

[0035] The foregoing describes certain embodiments of the invention. Other embodiments are within the scope of the following claims.

[0036] The terms "exemplary," "example," and the like used throughout this specification mean "used as an example, instance, or illustration" and do not mean "preferred" or "advantageous" over other embodiments. The detailed description includes specific details for the purpose of providing an understanding of the described techniques. However, these techniques can be implemented without these specific details. In some instances, in order to avoid obscuring the concepts of the described embodiments, well-known structures and devices are shown in block diagram form.

[0037] The optional implementation modes of the embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the embodiments of the present invention are not limited to the specific details in the above implementation modes. Within the technical concept of the embodiments of the present invention, various simple modifications can be made to the technical solutions of the embodiments of the present invention, and these simple modifications all belong to the protection scope of the embodiments of the present invention.

[0038] The above description of the contents of this specification is provided to enable any person of ordinary skill in the art to implement or use the contents of this specification. Various modifications to the contents of this specification will be apparent to those of ordinary skill in the art, and the general principles defined herein may be applied to other variations without departing from the scope of protection of the contents of this specification. Therefore, the contents of this specification are not limited to the examples and designs described herein, but are consistent with the widest range of principles and novel features disclosed herein.

Claims

1. A multi-energy storage system, characterized in that: include: A temperature control component (1), a compression network (2), a cold storage device (3), a working fluid gas preparation network (4) and a switching circuit (5); the cold side of the first temperature control device (11) is connected to the cold side of the fourth temperature control device (14), and flows back to the hot side of the first temperature control device (11) through the cold side of the second temperature control device (12); the hot side of the second temperature control device (12) is connected to the hot side of the first turbine (6) and the fifth temperature control device (15); the third temperature control device (13) is used to change the physical state of the working fluid in the compression network (2); the cold side of the fourth temperature control device (14) is connected to the output end of the compression network (2), and the fourth temperature control device (14) is connected to the output end of the compression network (2). The hot side of the device (14) is connected to the input end of the compression network (2) through the hot side of the cold storage device (3); the cold side of the cold storage device (3) is connected to the natural gas pipeline (7) and the working gas preparation network (4); the working gas preparation network (4) outputs working gas through the first turbine (6) performing work; the switching circuit (5) divides and mixes the working gas output from the compression network (2) and the working gas output from the working gas preparation network (4) through the fourth temperature control device (14) and the fifth temperature control device (15), so that the compression network (2) and the working gas preparation network (4) form a ring circuit for sufficient heat exchange.

2. A multi-energy storage system according to claim 1, characterized in that: The compression network (2) comprises: a low-pressure working fluid gas storage tank (21), a booster pump (22), a first compressor (23) and a high-pressure working fluid gas storage tank (24); the output end of the low-pressure working fluid gas storage tank (21) outputs liquid working fluid to the cold side of the third temperature control device (13) through the booster pump (22); the third temperature control device (13) is used to heat and evaporate the liquid working fluid and output the working fluid gas to the first compressor (23); the first compressor (23) is used to pressurize the working fluid gas and store it in the high-pressure working fluid gas storage tank (24) after passing through the cold side of the third temperature control device (13), so as to provide high-pressure working fluid gas for the switching circuit (5).

3. A multi-energy storage system according to claim 2, characterized in that: The switching circuit (5) comprises: a first condenser (51), a separator (52) and a second compressor (53); one end of the cold side of the fourth temperature control device (14) is connected to the output end of the high-pressure working medium gas storage tank (24) through a first three-way joint A, and the other end of the cold side of the fourth temperature control device (14) is connected to the cold side of the first temperature control device (11) through a second three-way joint B, and further connected to the second turbine (8) through the cold side of the second temperature control device (12); the second compressor (53) and the hot side of the first temperature control device (11) are connected through a third three-way joint. The connector C is connected to the hot side of the fourth temperature control device (14); the first condenser (51) receives the working gas input from the hot side of the second temperature control device (12) through the hot side of the fifth temperature control device (15) to condense the working gas output from the working gas preparation network (4); the separator (52) is used to separate the working gas and liquid water condensed by the first condenser (51); the second compressor (53) is used to compress the working gas output from the separator (52) and output it to one end of the hot side of the fourth temperature control device (14) through the third three-way connector C.

4. A multi-energy storage system according to claim 3, characterized in that: The working gas preparation network (4) comprises: an electrolyzer (41), an oxygen storage tank (42), a hydrogen storage tank (43) and a combustion chamber (44); the electrolyzer (41) is used for electrolyzing water and storing the generated oxygen and hydrogen in the oxygen storage tank (42) and the hydrogen storage tank (43) respectively; the combustion chamber (44) is used for connecting the oxygen storage tank (42) and the natural gas pipeline (7) to output the generated working gas to the first turbine (6) by burning the natural gas.

5. A multi-energy storage system according to claim 4, characterized in that: The multi-energy storage system further comprises a methanol preparation loop (9), and the temperature control component (1) further comprises a sixth temperature control device (16); the methanol preparation loop (9) comprises: a methanol synthesizer (91), a methanol separator (92), a mixer (93) and a third compressor (94); the methanol synthesizer (91) is connected to the cold side of the sixth temperature control device (16) and the hot side of the sixth temperature control device (16) to output a synthesized product to the methanol separator (92); the methanol synthesizer (91) and the mixer (93) are connected via the sixth temperature control device (16); one side of the mixer (93) is connected to the third compressor (94) and receives part of the working fluid gas output by the fourth temperature control device (14) via a fourth three-way connector D to output a mixed gas to the cold side of the sixth temperature control device (16); the third compressor (94) is used to compress the hydrogen output by the hydrogen storage tank (43) to output high-pressure hydrogen to the mixer (93).

6. A multi-energy storage system according to claim 4, characterized in that: The output end of the natural gas pipeline (7) passes through the third turbine (71) and then through the cold side of the cold storage device (3) to supply gas to the combustion chamber (44) and the terminal user respectively.

7. A multi-energy storage system according to claim 4, characterized in that: The cold side output flow rate of the first temperature regulating device (11) is equal to the hot side output flow rate of the fourth temperature regulating device (14).

8. A multi-energy storage system according to claim 7, characterized in that: The pressure of the working gas output by the second compressor (53) is equal to the pressure of the working gas output by the first temperature regulating device (11).

9. A multi-energy storage method, applied to a multi-energy storage system as claimed in any one of claims 1 to 8, characterized in that: The compression network (2), the cold storage device (3), the working fluid gas preparation network (4) and the switching circuit (5) are connected through the temperature control component (1) to form a heat exchange circuit; when the working fluid circulates in the heat exchange circuit, the working fluid gas output from the working fluid gas preparation network (4) performs work through the first turbine (6) and energizes the heat exchange circuit; the natural gas pipeline (7) is coupled to the heat exchange circuit through the cold storage device (3), and the natural gas output from the natural gas pipeline (7) is energized after passing through the first turbine (6). After the combustion reaction, the heat exchange circuit is energized; the cold storage device (3) absorbs energy from the heat exchange circuit and changes the physical state of the working fluid flowing into the compression network (2); the compression network (2) changes the physical state of the working fluid and stores the energy transmitted from the low-pressure side of the heat exchange circuit; the switching circuit (5) diverts and mixes the working fluid gas output from the high-pressure side of the heat exchange circuit and the working fluid gas output from the low-pressure side of the heat exchange circuit, thereby reducing the temperature difference between the hot side and the cold side of each of the temperature control components (1) during the heat recovery process.

10. A multi-energy storage method according to claim 9, characterized in that: The low-pressure working fluid gas flowing out of the switching circuit enters the compression network (2) and the methanol preparation network (8) respectively, thereby storing the energy transferred by the low-pressure side of the heat exchange.

Images