Carbon dioxide energy storage system, its storage device, and working method of the storage device

Abstract

The present disclosure provides a carbon dioxide energy storage system, its storage device, and a working method of the storage device; it relates to the technical field of carbon dioxide energy storage; the storage device includes a liquid storage container, a heat exchange module, and a spraying structure. The internal cavity of the liquid storage container includes a spraying area located in the upper part and a liquid storage area located in the lower part; the liquid storage container has at least one gaseous carbon dioxide interface in the spraying area; the heat exchange module is located in the liquid storage area; both the inlet and the outlet of the heat exchange module extend outside the liquid storage container; the heat exchange module is at least used to flow in a heat supply medium to evaporate liquid carbon dioxide during the energy release stage; the spraying structure includes a spraying head; the spraying head is used to spray liquid supercooled carbon dioxide into the spraying area during the energy storage stage, and the liquid supercooled carbon dioxide is liquid carbon dioxide with a temperature lower than the dew point of the gaseous carbon dioxide in the spraying area. This storage device can reduce the number of devices, and improve the condensation efficiency and the condensation conversion rate.

Description

Technical Field

[0001] The present disclosure relates to the technical field of carbon dioxide energy storage, and particularly relates to a carbon dioxide energy storage system, a storage device thereof, and a working method of the storage device. Background Art

[0002] The working process of a carbon dioxide gas-liquid phase change energy storage system includes an energy storage stage and an energy release stage. The specific operation method is to add a condenser on the energy storage side, complete the liquefaction process in the condenser, further cool the high-pressure gaseous carbon dioxide at the outlet of the compressor and condense it into a liquid state for storage in a liquid storage tank. On the energy release side, an evaporator is added at the outlet of the liquid storage tank, and the vaporization process is completed in the evaporator so that the carbon dioxide at the inlet of the expander reaches a gaseous state.

[0003] In the related art, a carbon dioxide gas-liquid phase change energy storage system needs to separately set a condenser, a liquid storage tank and an evaporator, and the process pipelines for the liquefaction process and the vaporization process are relatively long, the equipment basic investment is large, the system process is complex, and the operation difficulty is high.

[0004] It should be noted that the information disclosed in the above background art is only used to strengthen the understanding of the background of the present disclosure, and therefore may include information that does not constitute the prior art known to those of ordinary skill in the art. Summary of the Invention

[0005] The purpose of the present disclosure is to overcome the above-mentioned deficiencies of the prior art, and provide a carbon dioxide energy storage system, a storage device thereof, and a working method of the storage device, which can reduce the number of devices, improve the condensation efficiency and the condensation conversion rate.

[0006] According to one aspect of the present disclosure, a storage device of a carbon dioxide energy storage system is provided, including:

[0007] A liquid storage container, the internal cavity of the liquid storage container includes a spraying area located in the upper part and a liquid storage area located in the lower part; the liquid storage container has at least one gaseous carbon dioxide interface in the spraying area;

[0008] A heat exchange module, located in the liquid storage area; the inlet and outlet of the heat exchange module both extend outside the liquid storage container; the heat exchange module is at least used to flow in a heat supply medium to evaporate liquid carbon dioxide in the energy release stage;

[0009] A spraying structure, including a spraying head; the spraying head is used to spray liquid subcooled carbon dioxide into the spraying area in the energy storage stage, and the liquid subcooled carbon dioxide is liquid carbon dioxide with a temperature lower than the dew point of the gaseous carbon dioxide in the spraying area.

[0010] In an embodiment of the present disclosure, the spraying structure further includes a spraying pipe, a spraying liquid pump and a subcooler;

[0011] The liquid storage area of the liquid storage container is communicated with the spray head through the spray pipe. The spray liquid pump and the subcooler are both arranged on the spray pipe, and the subcooler is configured to reduce the temperature of the liquid carbon dioxide flowing through it.

[0012] In an embodiment of the present disclosure, the heat exchange module is further configured to allow an endothermic medium to flow in during the energy storage stage to cool the liquid carbon dioxide.

[0013] The spray structure further includes a spray pipe and a spray liquid pump.

[0014] The liquid storage area of the liquid storage container is communicated with the spray head through the spray pipe, and the spray liquid pump is arranged on the spray pipe.

[0015] In an embodiment of the present disclosure, the storage device further includes a liquid replenishing tank; the liquid replenishing tank is communicated with the liquid storage container through a liquid replenishing pipe.

[0016] The liquid replenishing tank is used to replenish liquid carbon dioxide to the liquid storage container.

[0017] In an embodiment of the present disclosure, the position of the liquid replenishing tank is higher than the position of the liquid storage container, and one end of the liquid replenishing pipe connected to the liquid replenishing tank is not lower than one end of the liquid replenishing pipe connected to the liquid storage container.

[0018] In an embodiment of the present disclosure, a driving pump is arranged on the liquid replenishing pipe.

[0019] The driving pump is at least configured to be able to transfer at least part of the liquid carbon dioxide in the liquid storage container into the liquid replenishing tank.

[0020] In an embodiment of the present disclosure, the storage device further includes an auxiliary liquid storage structure.

[0021] The auxiliary liquid storage structure includes an auxiliary liquid storage tank; the inlet of the auxiliary liquid storage tank is communicated with the liquid outlet of the liquid storage container through a first liquid storage pipe, and the outlet of the auxiliary liquid storage tank is communicated with the liquid inlet of the liquid storage container through a second liquid storage pipe. At least one of the first liquid storage pipe and the second liquid storage pipe is provided with a liquid storage pump.

[0022] In an embodiment of the present disclosure, the heat exchange module is a heat exchange pipe.

[0023] According to another aspect provided by the present disclosure, there is provided a carbon dioxide energy storage system including the above storage device.

[0024] According to another aspect provided by the present disclosure, there is provided a working method of a storage device, including:

[0025] During the energy storage stage, liquid supercooled carbon dioxide is sprayed to condense gaseous carbon dioxide;

[0026] During the energy release stage, a heat supply medium flows in to evaporate the liquid carbon dioxide.

[0027] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present disclosure. Brief Description of the Drawings

[0028] The drawings herein are incorporated into the specification and form a part of the specification, showing embodiments consistent with the present disclosure, and are used together with the specification to explain the principles of the present disclosure. Obviously, the drawings in the following description are only some embodiments of the present disclosure, and those of ordinary skill in the art can obtain other drawings based on these drawings without creative efforts.

[0029] Figure 1 In one embodiment of the present disclosure, it is a schematic diagram of a carbon dioxide energy storage system.

[0030] Figure 2 In one embodiment of the present disclosure, it is a schematic diagram of a carbon dioxide energy storage system.

[0031] Figure 3 In one embodiment of the present disclosure, it is a schematic diagram of a carbon dioxide energy storage system.

[0032] Figure 4 In one embodiment of the present disclosure, it is a schematic diagram of a storage device.

[0033] Figure 5 In one embodiment of the present disclosure, it is a schematic diagram of a storage device.

[0034] Figure 6 In one embodiment of the present disclosure, it is a schematic diagram of a carbon dioxide energy storage system.

[0035] Figure 7 In one embodiment of the present disclosure, it is a schematic diagram of a carbon dioxide energy storage system.

[0036] Figure 8 In one embodiment of the present disclosure, it is a schematic diagram of a carbon dioxide energy storage system.

[0037] Figure 9 In one embodiment of the present disclosure, it is a schematic diagram of a carbon dioxide energy storage system.

[0038] Figure 10 In one embodiment of the present disclosure, it is a schematic diagram of a carbon dioxide energy storage system. Detailed Description of the Embodiments

[0039] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in various forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the example embodiments to those skilled in the art. Like reference numerals in the figures denote like or similar structures and thus their detailed description will be omitted. In addition, the drawings are only schematic illustrations of the present disclosure and are not necessarily drawn to scale.

[0040] Although relative terms such as "upper" and "lower" are used in this specification to describe the relative relationship of one component of an icon to another component, these terms are used in this specification only for convenience, for example, according to the directions of the examples described in the drawings. It can be understood that if the device of the icon is turned upside down, the component described as "upper" will become the component "lower". When a structure is "on" another structure, it may mean that a structure is integrally formed on another structure, or that a structure is "directly" disposed on another structure, or that a structure is "indirectly" disposed on another structure through another structure.

[0041] The terms "a", "an", "the", and "said" are used to denote the presence of one element / component / etc.; the terms "comprising" and "having" are used to mean an open inclusion and mean that there may be additional elements / components / etc. in addition to the listed elements / components / etc.; the terms "first", "second", and "third", etc. are used only as labels and are not a limitation on the quantity of their objects.

[0042] The embodiments of the present disclosure provide a carbon dioxide energy storage system. Refer to Figure 1, the carbon dioxide energy storage system includes a gas storage device 100, and an energy storage component 200, a storage device 300, and an energy release component 400 that are connected in sequence. Among them, the gas storage device 100 is connected to the inlet of the energy storage component 200, the outlet of the energy storage component 200 is connected to the inlet of the storage device 300, the outlet of the storage device 300 is connected to the inlet of the energy release component 400, and the outlet of the energy release component 400 is connected to the gas storage device 100. Among them, the gas storage device 100 can store gaseous carbon dioxide, for example, store gaseous carbon dioxide at low temperature and low pressure; the storage device 300 can condense gaseous carbon dioxide, store, and evaporate liquid carbon dioxide. Among them, the energy storage component 200 can use electricity to compress the gaseous carbon dioxide from the gas storage device 100 to achieve energy storage; the storage device 300 can cool down the compressed gaseous carbon dioxide, for example, cool the compressed gaseous carbon dioxide until it condenses into liquid carbon dioxide and stores it, or make the cooled gaseous carbon dioxide enter the storage device 300 and be condensed into liquid carbon dioxide and stored. The storage device 300 can also heat the stored liquid carbon dioxide, for example, evaporate the liquid carbon dioxide stored in the storage device 300 into gaseous carbon dioxide and send it to the energy release component 400, and the energy release component 400 heats up the gaseous carbon dioxide and makes the heated gaseous carbon dioxide expand to generate electricity.

[0043] For example, in the energy storage stage, the energy storage component 200 can compress the gaseous carbon dioxide from the gas storage device 100, and the storage device 300 can condense the compressed gaseous carbon dioxide, so that the gaseous carbon dioxide changes phase into liquid carbon dioxide and is stored in the storage device 300. In the energy release stage, the storage device 300 can evaporate the liquid carbon dioxide stored therein into gaseous carbon dioxide, and the energy release component 400 can expand and generate electricity for the gaseous carbon dioxide from the storage device 300, so that the gaseous carbon dioxide that has completed the expansion power generation is stored in the gas storage device 100.

[0044] In an embodiment of the present disclosure, the gas storage device 100 can be a gas storage bin.

[0045] In an embodiment of the present disclosure, refer to Figure 2, the energy storage component 200 includes at least one compressed energy storage part 201; the compressed energy storage part 201 includes a compressor 21 and an energy storage heat exchanger 22, and each compressed energy storage part 201 is connected to the gas storage device 100 and the storage device 300. Specifically, the inlet of each compressed energy storage part 201 is connected to the gas storage device 100, and the outlet of each compressed energy storage part 201 is connected to the storage device 300. The compressor 21 can compress the gaseous carbon dioxide from the gas storage device 100 under electric drive, compress the low-temperature and low-pressure gaseous carbon dioxide into high-temperature and high-pressure gaseous carbon dioxide, and the compressed carbon dioxide can be cooled by heat exchange in the energy storage heat exchanger 22. After the high-temperature and high-pressure gaseous carbon dioxide is cooled by heat exchange in the energy storage heat exchanger 22, it forms low-temperature and high-pressure gaseous carbon dioxide.

[0046] In Figure 2 's example, the energy storage component 200 includes three compressed energy storage parts 201. It can be understood that in other embodiments of the present disclosure, the number of compressed energy storage parts 201 in the energy storage component 200 is not limited to 3, for example, it can be 1, or multiple of other numbers (such as 2, 4, 5, or 6).

[0047] In an embodiment of the present disclosure, the compressed energy storage part 201 includes one compressed energy storage unit or multiple compressed energy storage units cascaded in sequence. One compressed energy storage unit can include one compressor 21 and one energy storage heat exchanger 22; the outlet of the compressor 21 is connected to the carbon dioxide inlet of the energy storage heat exchanger 22; in this way, after the gaseous carbon dioxide is compressed in the compressor 21, it flows into the energy storage heat exchanger 22 for heat exchange cooling. When the compressed energy storage part 201 includes multiple compressed energy storage units cascaded in sequence, between two adjacent compressed energy storage units, the carbon dioxide outlet of the energy storage heat exchanger 22 of the upper-level compressed energy storage unit is connected to the inlet of the compressor 21 of the lower-level compressed energy storage unit. In Figure 2 's example, the compressed energy storage part 201 includes two compressed energy storage units. It can be understood that according to needs, the number of compressed energy storage units in the compressed energy storage part 201 can be one, or 2 or more.

[0048] In Figure 2 's example, the solid arrows indicate the flow direction of carbon dioxide in the compressed energy storage part 201, and the dashed arrows indicate the flow direction of the cooling medium flowing through the energy storage heat exchanger 22. In the energy storage heat exchanger 22, the compressed carbon dioxide with a higher temperature exchanges heat with the cooling medium with a lower temperature, so that the carbon dioxide is cooled and thus is conducive to being condensed into liquid carbon dioxide, and the cooling medium absorbs heat and warms up to recover the heat generated during the carbon dioxide compression process.

[0049] In an embodiment of the present disclosure, the inlet of the first-stage compressor 21 of the compression energy storage unit 201 is connected to the gas storage device 100. It can be understood that when there is only one compression energy storage unit in the compression energy storage unit 201, the inlet of the compressor 21 of the compression energy storage unit 201 is connected to the gas storage device 100. Further, a second valve 11 may be provided between the inlet of the first-stage compressor 21 and the gas storage device 100, and the second valve 11 is used to adjust and control the flow rate of the gaseous carbon dioxide flowing through it. In Figures 6 to 10 In the exemplified carbon dioxide energy storage system, only the first-stage compressor 21 of the compression energy storage unit 201 is shown, and each compressor 21 represents that there is a corresponding compression energy storage unit 201 in the carbon dioxide energy storage system.

[0050] In an embodiment of the present disclosure, referring to Figure 3 , the energy release component 400 includes at least one expansion energy release unit 401; the expansion energy release unit 401 includes a turbine 41 and an energy release heat exchanger 42, and each expansion energy release unit 401 is connected to the gas storage device 100 and the storage device 300. Specifically, the inlet of each expansion energy release unit 401 is connected to the storage device 300, and the outlet of each expansion energy release unit 401 is connected to the gas storage device 100. The carbon dioxide from the storage device 300 can absorb heat in the energy release heat exchanger 42 and then enter the turbine 41, thereby driving the generator G to generate electricity.

[0051] In Figure 3 's example, the energy release component 400 includes three expansion energy release units 401. It can be understood that in other embodiments of the present disclosure, the number of expansion energy release units 401 in the energy release component 400 is not limited to 3, for example, it can be 1, or multiple of other numbers (such as 2, 4, 5, or 6).

[0052] In an embodiment of the present disclosure, the expansion energy release unit 401 includes one expansion energy release unit or multiple expansion energy release units connected in series. One expansion energy release unit may include one turbine 41 and one energy release heat exchanger 42; the carbon dioxide outlet of the energy release heat exchanger 42 is connected to the inlet of the turbine 41; in this way, after the carbon dioxide absorbs heat in the energy release heat exchanger 42, it flows into the turbine 41 for expansion power generation. When the expansion energy release unit 401 includes multiple expansion energy release units connected in series, between two adjacent expansion energy release units, the outlet of the turbine 41 of the upper-stage expansion energy release unit is connected to the carbon dioxide inlet of the energy release heat exchanger 42 of the lower-stage expansion energy release unit. In Figure 3 's example, the expansion energy release unit 401 includes two expansion energy release units. It can be understood that according to needs, the number of expansion energy release units in the expansion energy release unit 401 can be one, or 2 or more.

[0053] In Figure 3In the example, the solid arrow indicates the flow direction of carbon dioxide in the expansion energy release section 401, and the dashed arrow indicates the flow direction of the heating medium flowing through the energy release heat exchanger 42. In the energy release heat exchanger 42, the carbon dioxide that flows out of the storage device 300 and expands and cools exchanges heat with the heating medium at a higher temperature, thereby heating and raising the temperature of the carbon dioxide. This can recover the cold energy generated by the expansion of gaseous carbon dioxide.

[0054] In an embodiment of the present disclosure, the outlet of the last-stage turbine 41 of the expansion energy release section 401 is connected to the gas storage device 100. It can be understood that when the expansion energy release section 401 has only one expansion energy release unit, the outlet of the turbine 41 of the expansion energy release section 401 is connected to the gas storage device 100. Optionally, a sixth valve 15 is provided between the outlet of the last-stage turbine 41 of the expansion energy release section 401 and the gas storage device 100. Among them, the sixth valve 15 serves as a switching valve, which is closed during the energy storage stage and opened during the energy release stage. In Figures 6 to 10 In the illustrated carbon dioxide energy storage system, only the last-stage turbine 41 of the expansion energy release section 401 is shown, and each turbine 41 represents the existence of a corresponding expansion energy release section 401.

[0055] It can be understood that in other embodiments of the present disclosure, the carbon dioxide energy storage system may also be provided with other components. In one example, the carbon dioxide energy storage system may also be provided with a heat energy recovery component, which includes a heat storage tank 24 and a cold storage tank 23. During the energy storage stage, the energy storage heat exchanger 22 can exchange heat with the low-temperature medium from the cold storage tank 23 (i.e., the cooling medium flowing into the energy storage heat exchanger 22), which causes the carbon dioxide in the energy storage heat exchanger 22 to be cooled, and the low-temperature medium is heated to a high-temperature medium and stored in the heat storage tank 24. During the energy release stage, the energy release heat exchanger 42 can exchange heat with the high-temperature medium from the heat storage tank 24 (i.e., the heating medium flowing into the energy release heat exchanger 42), which causes the carbon dioxide in the energy release heat exchanger 42 to be heated, and the high-temperature medium is cooled to a low-temperature medium and stored in the cold storage tank 23. In this example, the heating medium and the cooling medium are heat exchange media circulating between the heat storage tank 24 and the cold storage tank 23, and their temperature states are different.

[0056] In an embodiment of the present disclosure, taking the compression energy storage section 201 including one compression energy storage unit and the expansion energy release section 401 including one expansion energy release unit as an example, see Figures 6 - 10 , the inlet of the compressor 21 is communicated with the outlet of the gas storage device 100 through the third pipeline 8, the inlet of the energy storage heat exchanger 22 is communicated with the outlet of the compressor 21 through the fourth pipeline 9, and the outlet of the energy storage heat exchanger 22 is communicated with the storage device 300 through the fifth pipeline 20. In this example, the second valve 11 is provided on the third pipeline 8.

[0057] In an embodiment of the present disclosure, referring to Figures 6 - 10 , the energy storage heat exchanger 22 has a gaseous carbon dioxide outlet and a gaseous carbon dioxide inlet. The outlet of the compressor 21 is communicated with the gaseous carbon dioxide inlet of the energy storage heat exchanger 22 through the fourth pipeline 9, and the gaseous carbon dioxide outlet of the energy storage heat exchanger 22 is communicated with the storage device 300 through the fifth pipeline 20. The energy storage heat exchanger 22 also has a first medium inlet and a first medium outlet. The cold storage tank 23 is communicated with the first medium inlet through the first pipeline 6, and the first medium outlet is communicated with the heat storage tank 24 through the second pipeline 7. A first circulation pump 25 is provided on the first pipeline 6, and a first valve 10 is provided on the first pipeline 6 between the first circulation pump 25 and the first medium inlet. In this example, the heat storage tank 24 is used to store the high-temperature medium after absorbing the heat of the gaseous carbon dioxide, the cold storage tank 23 is used to store the low-temperature medium after releasing the heat of the carbon dioxide, the first circulation pump 25 is used to transport the low-temperature medium to the energy storage heat exchanger 22; the first valve 10 is used to adjust and control the flow rate of the low-temperature medium in the cold storage tank 23 entering the energy storage heat exchanger 22.

[0058] In an embodiment of the present disclosure, the low-temperature medium and the high-temperature medium may be water, heat-conducting oil, molten salt, etc. Of course, in other examples, the low-temperature medium and the high-temperature medium may also be other components not shown.

[0059] In an embodiment of the present disclosure, the inlet of the energy release heat exchanger 42 is communicated with the storage device 300 through the sixth pipeline 1. The outlet of the energy release heat exchanger 42 is communicated with the inlet of the turbine 41 through the seventh pipeline 2. The turbine 41 is configured with a generator G, and the generator G is used to convert the mechanical energy of the high-temperature and high-pressure gaseous carbon dioxide expanding and doing work in the turbine 41 into electrical energy. The outlet of the turbine 41 is communicated with the inlet of the gas storage device 100 through the eighth pipeline 3, and a sixth valve 15 is provided on the eighth pipeline 3.

[0060] In an embodiment of the present disclosure, the turbine 41 is used to expand and do work on the high-temperature and high-pressure gaseous carbon dioxide to become low-temperature and low-pressure gaseous carbon dioxide, and the generator G is used to convert the mechanical energy of the high-temperature and high-pressure gaseous carbon dioxide expanding and doing work in the turbine into electrical energy.

[0061] In an embodiment of the present disclosure, referring to Figures 6 - 10, the energy-releasing heat exchanger 42 has a gaseous carbon dioxide outlet and a gaseous carbon dioxide inlet. The outlet of the storage device 300 is communicated with the gaseous carbon dioxide inlet of the energy-releasing heat exchanger 42 through the sixth pipeline 1, and the gaseous carbon dioxide outlet of the energy-releasing heat exchanger 42 is communicated with the turbine 41 through the seventh pipeline 2. The energy-releasing heat exchanger 42 also has a second medium inlet and a second medium outlet. The heat storage tank 24 is communicated with the second medium inlet through the ninth pipeline 4, and the second medium outlet is communicated with the cold storage tank 23 through the tenth pipeline 5. A second circulation pump 13 is provided on the ninth pipeline 4, and a fourth valve 14 is provided on the ninth pipeline 4 between the second circulation pump 13 and the second medium inlet. In this example, the second circulation pump 13 is used to transport the high-temperature medium to the energy-releasing heat exchanger 42; the fourth valve 14 is used to adjust and control the flow rate of the high-temperature medium in the heat storage tank 24 entering the energy-releasing heat exchanger 42. The energy-releasing heat exchanger 42 is used to transfer the heat of the high-temperature medium in the heat storage tank 24 to the low-temperature and high-pressure gaseous carbon dioxide, making it become high-temperature and high-pressure gaseous carbon dioxide. After the high-temperature medium releases heat, its temperature decreases and forms a low-temperature medium stored in the cold storage tank 23. In the present disclosure, the same set of cold storage tank 23 and heat storage tank 24 are used to realize the recycling of heat between the energy storage heat exchanger 22 and the energy-releasing heat exchanger 42, which not only improves the energy utilization rate, but also reduces the number of devices, simplifies the process and operation method, and reduces the cost.

[0062] In Figures 1 to 10 the example, the number of the storage devices 300 is one. It can be understood that in the embodiments of the present disclosure, the number of the storage devices 300 can also be multiple. When the number of the storage devices 300 is multiple, these storage devices 300 can be connected in series with each other, or in parallel with each other, or can be connected to each other in a series-parallel hybrid manner.

[0063] In the related art, the storage device includes a condenser, a liquid storage container, and an evaporator. The condenser is arranged between the last-stage compression energy storage unit and the liquid storage container. In other words, the carbon dioxide outlet of the last-stage energy storage heat exchanger can be connected to the carbon dioxide inlet of the condenser, and the carbon dioxide outlet of the condenser can be connected to the inlet of the liquid storage container. The condenser can condense the gaseous carbon dioxide from the compression energy storage unit, so that the low-temperature and high-pressure gaseous carbon dioxide from the compression energy storage unit is condensed into low-temperature and high-pressure liquid carbon dioxide and stored in the liquid storage container. The evaporator is arranged between the first-stage expansion energy-releasing unit and the liquid storage container. In other words, the carbon dioxide inlet of the first-stage energy-releasing heat exchanger can be connected to the carbon dioxide outlet of the evaporator, and the carbon dioxide inlet of the evaporator can be connected to the outlet of the liquid storage container. The evaporator can heat the low-temperature and high-pressure liquid carbon dioxide from the liquid storage container, so that the low-temperature and high-pressure liquid carbon dioxide from the liquid storage container evaporates into low-temperature and high-pressure gaseous carbon dioxide and flows into the energy-releasing heat exchanger.

[0064] In the related art, the condenser, the liquid storage container, and the evaporator in the storage device are independently arranged, resulting in relatively long process pipelines for the liquefaction process and the vaporization process, a relatively large equipment capital investment, a complex system process, and great operation difficulty.

[0065] To solve the above problems, refer to Figures 4 - 10 , the present disclosure provides a storage device 300. This storage device 300 realizes the integration of condensation, storage, and evaporation, reduces the process pipelines for the liquefaction process and the vaporization process, reduces costs, and is simple to operate.

[0066] In one example, refer to Figures 4 - 10 , the storage device 300 includes a liquid storage container 31, a heat exchange module 32, and a spraying structure.

[0067] In this example, refer to Figures 4 - 10 , the liquid storage container 31 has a cavity. The inside of the cavity is used to provide a space for the condensation phase change and evaporation phase change of carbon dioxide, a space for storing liquid carbon dioxide, and a space for arranging the heat exchange module 32 and the spraying structure. The cavity is divided into a spraying area RP and a liquid storage area RC from top to bottom (in other words, the cavity includes a spraying area RP located in the upper part and a liquid storage area RC located in the lower part). At least one gaseous carbon dioxide interface VO is arranged on the liquid storage container 31. In one example, the spraying area RP and the liquid storage area RC can be dynamically adjusted based on the stock of liquid carbon dioxide in the liquid storage container 31.

[0068] In one example of the present disclosure, refer to Figure 4 , one gaseous carbon dioxide interface VO is arranged on the liquid storage container 31. At this time, this gaseous carbon dioxide interface VO serves as both a gaseous carbon dioxide outlet and a gaseous carbon dioxide inlet, and a T-shaped pipe is connected to this gaseous carbon dioxide interface VO. In one example, refer to Figure 4 , the first end of the T-shaped pipe is connected to the gaseous carbon dioxide interface VO, the second end of the T-shaped pipe is used to connect to the fifth pipe 20, the third end of the T-shaped pipe is used to connect to the sixth pipe 1, and a third valve 12 is arranged at the second end of the T-shaped pipe. The third valve 12 serves as a switching valve and is configured to be opened during the energy storage stage and closed during the energy release stage. A fifth valve 16 is arranged at the third end of the T-shaped pipe. Among them, the fifth valve 16 is used to adjust and control the flow rate of the gaseous carbon dioxide outlet in the storage device 300. In another example, the T-shaped pipe can be formed by connecting three pipes through a three-way valve. The third valve 12 and the fifth valve 16 can control the flow direction of gaseous carbon dioxide (for example, when the third valve 12 is closed and the fifth valve 16 is opened, gaseous carbon dioxide flows out from the sixth pipe 1, and conversely, when the third valve 12 is opened and the fifth valve 16 is closed, gaseous carbon dioxide flows into the liquid storage container 31 from the fifth pipe 20).

[0069] In another example of the present disclosure, referring to Figures 5 - 10 , two gaseous carbon dioxide interfaces VO are provided on the liquid storage container 31. One of the gaseous carbon dioxide interfaces VO is a gaseous carbon dioxide outlet, and the other gaseous carbon dioxide interface VO is a gaseous carbon dioxide inlet. An outlet pipe 17 is connected to the gaseous carbon dioxide outlet, and a fifth valve 16 is provided on the outlet pipe 17. An inlet pipe 18 is connected to the gaseous carbon dioxide inlet, and a third valve 12 is provided on the inlet pipe 18. In this example, the fifth pipe 20 communicates with the inlet pipe 18, and the sixth pipe 1 communicates with the outlet pipe 17. In one example, the gaseous carbon dioxide inlet and the gaseous carbon dioxide outlet may be located at the same height of the liquid storage container 31. In other examples, the gaseous carbon dioxide inlet and the gaseous carbon dioxide outlet may be staggered along the vertical direction of the liquid storage container 31 (i.e., the gaseous carbon dioxide inlet and the gaseous carbon dioxide outlet are not at the same height). For example, the height of the gaseous carbon dioxide inlet on the liquid storage container 31 is higher than the height of the gaseous carbon dioxide outlet on the liquid storage container 31.

[0070] In one implementation method of the present disclosure, the gaseous carbon dioxide interface VO on the liquid storage container 31 may be located in the spraying area RP. In this way, the direct mixing contact time of the gaseous carbon dioxide and the liquid subcooled carbon dioxide can be extended, so that the gaseous carbon dioxide and the liquid subcooled carbon dioxide can be fully contacted, and the condensation efficiency of the gaseous carbon dioxide can be improved. In one example, the gaseous carbon dioxide inlet is higher than the gaseous carbon dioxide outlet, and similarly, the contact time of the low-temperature and high-pressure gaseous carbon dioxide entering the liquid storage container 31 and the liquid subcooled carbon dioxide can be extended, and the condensation efficiency of the gaseous carbon dioxide can be improved.

[0071] In one implementation manner of the present disclosure, referring to Figures 4 - 10 , a heat exchange medium flows in the heat exchange module 32 for heat exchange with carbon dioxide, so as to cause the phase change of carbon dioxide. In this example, the heat exchange module 32 is arranged in a cavity and is located in the liquid storage area RC. The inlet and outlet of the heat exchange module 32 both extend outside the liquid storage container 31. It can be understood that the heat exchange module 32 has a first end and a second end. Among them, the first end can be used as the inlet of the heat exchange module 32, and the second end can be used as the outlet of the heat exchange module 32. After the inlet and outlet of the heat exchange module 32 penetrate through the liquid storage container 31, they are placed outside the liquid storage container 31.

[0072] In one implementation manner of the present disclosure, the heat exchange module 32 may be a heat exchange tube. In other examples, the heat exchange module 32 may be a heat exchange fin. Of course, it can be understood that the heat exchange module 32 may also be other structures not shown.

[0073] In an embodiment of the present disclosure, a plurality of heat exchange teeth may be provided on the peripheral side of the heat exchange module 32, so that the heat transfer can be accelerated.

[0074] In an embodiment of the present disclosure, the number of the heat exchange modules 32 may be one. In other embodiments, the number of the heat exchange modules 32 may be multiple. In this way, the phase change conversion efficiency of carbon dioxide can be accelerated by increasing the contact area between carbon dioxide and the heat exchange module 32; and the phase change conversion efficiency of carbon dioxide can also be accelerated by increasing the total flow rate of the heat exchange medium entering the liquid storage area RC.

[0075] In an embodiment of the present disclosure, taking the heat exchange module 32 as a heat exchange tube as an example, the heat exchange tubes may be sequentially wound along the first direction, so that the contact area between carbon dioxide and the heat exchange tubes can be increased, and the conversion efficiency of carbon dioxide can be accelerated. In another embodiment, the heat exchange tubes may be sequentially wound along the second direction, so that the contact area between carbon dioxide and the heat exchange tubes can be increased, and the conversion efficiency of carbon dioxide can be accelerated. In another embodiment, the heat exchange tubes may be wound along the first direction and the second direction at the same time. In this way, the heat exchange tubes form a multi-layer structure, which can further increase the contact area between carbon dioxide and the heat exchange tubes, and accelerate the conversion efficiency of carbon dioxide. Wherein, the first direction intersects with the second direction. In one example, the second direction refers to the arrangement direction of the spray area RP and the liquid storage area RC, and the first direction is perpendicular to the second direction.

[0076] In this example, the inlet and outlet of the heat exchange module 32 are used to connect the medium conveying device. The medium conveying device can flow the heat exchange medium through the inlet of the heat exchange module 32 and flow out through the outlet, so that the liquid carbon dioxide in the liquid storage area RC can transfer heat with the heat exchange medium, realizing the function of evaporating the liquid carbon dioxide into gaseous carbon dioxide.

[0077] In an embodiment of the present disclosure, refer to Figures 6 - 10 , the spray structure includes a spray pipe 33, a spray liquid pump 34 and a spray head 35; wherein, the first end of the spray pipe 33 is communicated with the liquid storage area RC of the liquid storage container 31 (in other words, the liquid storage container 31 has a liquid carbon dioxide spray outlet in the liquid storage area RC, and the liquid carbon dioxide spray outlet is located at the bottom of the liquid storage container 31, and the first end of the spray pipe 33 is communicated with the liquid carbon dioxide spray outlet), the second end of the spray pipe 33 is communicated with the inlet of the spray head 35 (in this example, the first end of the spray pipe 33 is used as the inlet of the spray pipe 33, and the second end of the spray pipe 33 is used as the outlet of the spray pipe 33), the spraying end of the spray head 35 is located in the spray area RP inside the liquid storage container 31, and the spray liquid pump 34 is arranged on the spray pipe 33.

[0078] In the first embodiment of the present disclosure, refer to Figure 6, during the energy release stage, the heat exchange medium is the heat supply medium. In other words, the heat exchange module 32 is used to flow in the heat supply medium during the energy release stage to evaporate the liquid carbon dioxide. During the energy storage stage, the heat exchange medium is the heat absorption medium. In other words, the heat exchange module 32 is used to flow in the heat absorption medium during the energy release stage to condense the gaseous carbon dioxide, so that the gaseous carbon dioxide changes phase into liquid subcooled carbon dioxide. It can be understood that the heat exchange module 32 can not only condense the gaseous carbon dioxide into liquid carbon dioxide during the energy storage stage, but also further convert the liquid carbon dioxide into liquid subcooled carbon dioxide.

[0079] In this example, during the energy storage stage, the heat absorption medium is injected into the heat exchange module 32. The low-temperature and high-pressure gaseous carbon dioxide entering the liquid storage container 31 condenses into liquid carbon dioxide under the action of the heat absorption medium. During the continuous heat exchange with the heat absorption medium, the liquid carbon dioxide changes into liquid subcooled carbon dioxide. The spray liquid pump 34 of the spray structure extracts the liquid subcooled carbon dioxide and sprays it in the spray area RP through the spray head 35. The liquid subcooled carbon dioxide directly contacts and mixes with the low-temperature and high-pressure gaseous carbon dioxide continuously entering the liquid storage container 31, realizing the rapid phase change of gaseous carbon dioxide into liquid carbon dioxide, that is, completing the condensation process of carbon dioxide (it can be understood that the condensation process of carbon dioxide is through the direct contact between the liquid subcooled carbon dioxide sprayed by the spray structure and the gaseous carbon dioxide at the gaseous carbon dioxide inlet in the cavity of the liquid storage container 31, condensing the gaseous carbon dioxide into liquid carbon dioxide and storing it in the liquid storage area RC of the liquid storage container 31). The condensation efficiency of this condensation method is much higher than that of the existing wall-type condensation process. Or, on the premise that there is liquid carbon dioxide in the liquid storage container 31, the liquid carbon dioxide directly changes into liquid subcooled carbon dioxide during the heat exchange with the heat absorption medium. The spray structure extracts the liquid subcooled carbon dioxide and sprays it in the spray area RP, directly contacting and mixing with the low-temperature and high-pressure gaseous carbon dioxide entering the liquid storage container 31, realizing the rapid conversion of gaseous carbon dioxide into liquid carbon dioxide, that is, completing the condensation process of carbon dioxide.

[0080] In this embodiment, the present disclosure provides a method for using a carbon dioxide energy storage system, including:

[0081] In the first working mode (energy storage stage):

[0082] Open the second valve 11, the first valve 10, the third valve 12 and the seventh valve 19, and close the fifth valve 16, the fourth valve 14 and the sixth valve 15; The low-temperature and low-pressure gaseous carbon dioxide in the gas storage device 100 is compressed by the compressor 21 and becomes high-temperature and high-pressure gaseous carbon dioxide, which then enters the energy storage heat exchanger 22. The energy storage heat exchanger 22 exchanges heat with the low-temperature medium in the cold storage tank 23, transferring the heat of the high-temperature and high-pressure gaseous carbon dioxide in the energy storage heat exchanger 22 to the low-temperature medium, converting the high-temperature and high-pressure gaseous carbon dioxide into low-temperature and high-pressure gaseous carbon dioxide, and converting the low-temperature medium in the cold storage tank 23 into a high-temperature medium and storing it in the heat storage tank 24. The low-temperature and high-pressure gaseous carbon dioxide enters the liquid storage container 31, and an endothermic medium is introduced into the heat exchange module 32. The endothermic medium exchanges heat with the liquid carbon dioxide in the liquid storage container 31, causing the liquid carbon dioxide to form supercooled liquid carbon dioxide (or the endothermic medium exchanges heat with the gaseous carbon dioxide entering the liquid storage container 31, causing the gaseous carbon dioxide to condense into liquid carbon dioxide, and the liquid carbon dioxide continues to exchange heat with the endothermic medium, causing the liquid carbon dioxide to form supercooled liquid carbon dioxide). The spray liquid pump 34 extracts the supercooled liquid carbon dioxide from the liquid storage container 31 and sprays it through the spray head 35 in the spray area RP of the liquid storage container 31. The gaseous carbon dioxide entering the liquid storage container 31 directly mixes and contacts with the supercooled liquid carbon dioxide, causing the low-temperature and high-pressure gaseous carbon dioxide to condense into low-temperature and high-pressure liquid carbon dioxide and be stored in the liquid storage container 31. During the off-peak power period, the carbon dioxide energy storage system can operate in the first working mode, using surplus power to drive the compression of gaseous carbon dioxide, condensing it into liquid carbon dioxide for storage, and simultaneously storing the thermal energy generated during the compression process.

[0083] In the second working mode (energy release stage):

[0084] Open the fifth valve 16, the fourth valve 14, and the sixth valve 15, close the second valve 11, the first valve 10, the third valve 12, and the seventh valve 19, and inject the heat supply medium into the heat exchange module 32. The low-temperature and high-pressure liquid carbon dioxide stored in the liquid storage container 31 exchanges heat with the heat supply medium in the heat exchange module 32, transfers the heat of the heat supply medium in the heat exchange module 32 to the low-temperature and high-pressure liquid carbon dioxide, completes the evaporation process of the liquid carbon dioxide, and becomes low-temperature and high-pressure gaseous carbon dioxide and enters the energy release heat exchanger 42, where it exchanges heat with the high-temperature medium in the heat storage tank 24, transfers the heat of the high-temperature medium to the low-temperature and high-pressure gaseous carbon dioxide, causes the high-temperature medium in the heat storage tank 24 to become a low-temperature medium and stores it in the cold storage tank 23. The low-temperature and high-pressure gaseous carbon dioxide absorbs heat and becomes high-temperature and high-pressure gaseous carbon dioxide and enters the turbine 41 to expand and do work. The generator G converts the mechanical energy of the expansion work of the turbine 41 into electrical energy. The low-temperature and low-pressure gaseous carbon dioxide after expansion work returns to the gas storage device 100 for storage, completing the energy release stage. This mode is used to work during the peak electricity consumption period, vaporize liquid carbon dioxide using low-grade heat, promote the expansion of gaseous carbon dioxide through the thermal energy stored in the first working mode, drive the turbine 41 to generate electricity, store the expanded low-temperature and low-pressure gaseous carbon dioxide in the gas storage device 100, and perform the next cycle.

[0085] In the present disclosure, through the provided integrated storage device 300 for condensation, storage, and evaporation, the sprayed liquid subcooled carbon dioxide is directly contacted and mixed with the gaseous carbon dioxide entering the liquid storage container 31 by means of the spraying structure, realizing the condensation phase change of gaseous carbon dioxide into liquid carbon dioxide (liquid subcooled carbon dioxide), and realizing the cycle of carbon dioxide phase change (the liquid carbon dioxide formed by the condensation of gaseous carbon dioxide can be subcooled to form liquid subcooled carbon dioxide and then continue to be used for the condensation of gaseous carbon dioxide). The heat supply medium flowing in the heat exchange module 32 causes the liquid carbon dioxide (liquid subcooled carbon dioxide) to phase change into gaseous carbon dioxide, realizing the integration of condensation, storage, and evaporation functions, which can reduce the number of devices and the pipeline design and construction volume in the carbon dioxide energy storage system. And due to the reduction of the number of devices in the carbon dioxide energy storage system (such as reducing the number of liquid pumps), the loss of pressure energy is reduced, the energy consumption of the carbon dioxide energy storage system is reduced, the equipment investment of the carbon dioxide energy storage system is reduced, the risk of equipment corrosion is reduced, the maintenance and repair cost is reduced, and the operation process is optimized.

[0086] A new method for condensing and phase-changing gaseous carbon dioxide is provided in the present disclosure (a condensation process that directly contacts liquid subcooled carbon dioxide with gaseous carbon dioxide to complete the condensation of gaseous carbon dioxide), which has a higher heat transfer efficiency and can condense more quickly. Under the same heat load, the internal components required in the equipment are simpler, which can significantly reduce the equipment investment. Compared with the indirect wall condensation in the related technology, this highly efficient mixed condensation method can significantly increase the heat transfer coefficient, making the condensation process faster and more efficient. In addition, the present disclosure optimizes the operation process during the operation of the carbon dioxide energy storage system, which can improve the reliability of the operation of the carbon dioxide energy storage system, as well as increase the efficiency of the energy storage system and the energy utilization rate; it can also reduce the floor area of the equipment, lower the equipment cost of the entire energy storage system, and facilitate the popularization and use of the gas-liquid phase change carbon dioxide energy storage system.

[0087] In the second embodiment of the present disclosure, refer to Figure 8 , the heat exchange medium is a heat supply medium. In other words, the heat exchange module 32 is only used to flow into the heat supply medium during the energy release stage to evaporate the liquid carbon dioxide.

[0088] In this example, the spraying structure further includes a subcooler 44. The subcooler 44 is arranged on the spraying pipe 33, and the subcooler 44 is located between the spraying liquid pump 34 and the liquid outlet of the liquid storage container 31. The subcooler 44 is configured to lower the temperature of the liquid carbon dioxide flowing through it. In other words, the subcooler 44 is configured to convert the liquid carbon dioxide flowing through it into liquid subcooled carbon dioxide. The spraying liquid pump 34 is configured to transport the liquid subcooled carbon dioxide to the inlet of the spraying head 35 through the spraying pipe 33 (of course, in other examples, the subcooler 44 can also be located between the spraying liquid pump 34 and the spraying head 35, and the spraying liquid pump 34 is configured to transport the liquid carbon dioxide to the inlet of the spraying head 35 through the spraying pipe 33, and then the subcooler 44 subcools the liquid carbon dioxide). A seventh valve 19 is arranged between the spraying liquid pump 34 and the subcooler 44 on the spraying pipe 33, and the seventh valve 19 is used to adjust and control the flow rate of the carbon dioxide flowing through it. Among them, the liquid subcooled carbon dioxide is the liquid carbon dioxide whose temperature is lower than the dew point of the gaseous carbon dioxide in the spraying area RP.

[0089] In this embodiment, the present disclosure provides a method for using a carbon dioxide energy storage system, including:

[0090] In the first working mode (energy storage stage):

[0091] Open the second valve 11, the first valve 10, the third valve 12 and the seventh valve 19, and close the fifth valve 16, the fourth valve 14, and the sixth valve 15. The low-temperature and low-pressure gaseous carbon dioxide in the gas storage device 100 is compressed by the compressor 21 and becomes high-temperature and high-pressure gaseous carbon dioxide, which then enters the energy storage heat exchanger 22. In the energy storage heat exchanger 22, the high-temperature and high-pressure gaseous carbon dioxide exchanges heat with the low-temperature medium in the cold storage tank 23, transferring the heat of the high-temperature and high-pressure gaseous carbon dioxide in the energy storage heat exchanger 22 to the low-temperature medium, causing the low-temperature medium in the cold storage tank 23 to become a high-temperature medium and be stored in the heat storage tank 24. The high-temperature and high-pressure gaseous carbon dioxide is transformed into low-temperature and high-pressure gaseous carbon dioxide and enters the liquid storage container 31. The spray liquid pump 34 extracts the liquid carbon dioxide in the liquid storage container 31 (the liquid carbon dioxide in the liquid storage container 31 can be the liquid carbon dioxide pre-retained in the liquid storage container 31). This liquid carbon dioxide is subcooled by the subcooler 44 and then sprayed in the spray area RP of the liquid storage container 31 using the spray head 35. The gaseous carbon dioxide entering the liquid storage container 31 directly mixes and contacts the liquid subcooled carbon dioxide, causing the low-temperature and high-pressure gaseous carbon dioxide to condense into low-temperature and high-pressure liquid carbon dioxide and be stored in the liquid storage container 31.

[0092] In the second working mode (energy release stage):

[0093] Open the fifth valve 16, the fourth valve 14, and the sixth valve 15, and close the second valve 11, the first valve 10, the third valve 12, and the seventh valve 19, and inject the heat supply medium into the heat exchange module 32. The low-temperature and high-pressure liquid carbon dioxide stored in the liquid storage container 31 exchanges heat with the heat supply medium in the heat exchange module 32, transferring the heat of the heat supply medium in the heat exchange module 32 to the low-temperature and high-pressure liquid carbon dioxide, completing the evaporation process of the liquid carbon dioxide and becoming low-temperature and high-pressure gaseous carbon dioxide, which enters the energy release heat exchanger 42 and exchanges heat with the high-temperature medium in the heat storage tank 24, transferring the heat of the high-temperature medium to the low-temperature and high-pressure gaseous carbon dioxide, causing the high-temperature medium in the heat storage tank 24 to become a low-temperature medium and be stored in the cold storage tank 23. The low-temperature and high-pressure gaseous carbon dioxide absorbs heat and becomes high-temperature and high-pressure gaseous carbon dioxide, which enters the turbine 41 to expand and do work. The generator G converts the mechanical energy of the turbine 41 expanding and doing work into electrical energy. The low-temperature and low-pressure gaseous carbon dioxide after expanding and doing work returns to the gas storage device 100 for storage, completing the energy release stage.

[0094] In the present disclosure, through the integrated storage device 300 provided, the liquid subcooled carbon dioxide is sprayed by the spraying structure and directly contacts and mixes with the gaseous carbon dioxide entering the liquid storage container 31, so as to realize the condensation phase change of gaseous carbon dioxide into liquid carbon dioxide (liquid subcooled carbon dioxide), and realize the cycle of carbon dioxide phase change (the sprinkler head 35 sprays liquid subcooled carbon dioxide in the spraying area RP), and the heat supply medium flowing in the heat exchange module 32 is used to make the liquid carbon dioxide (liquid subcooled carbon dioxide) phase change into gaseous carbon dioxide, realizing the integration of condensation, storage and evaporation functions, and can reduce the number of devices and the pipeline design and construction volume in the carbon dioxide energy storage system. Since the number of devices in the energy storage system is reduced (for example, the number of liquid pumps is reduced), the loss of pressure energy is reduced, the energy consumption of the carbon dioxide energy storage system is reduced, the equipment investment of the carbon dioxide energy storage system is reduced, the equipment corrosion risk is reduced, the maintenance cost is reduced, and the operation process is optimized.

[0095] In the present disclosure, a new method for the condensation phase change of gaseous carbon dioxide is provided (adopting a condensation process in which liquid subcooled carbon dioxide directly contacts gaseous carbon dioxide to complete the condensation of gaseous carbon dioxide), and has a higher heat transfer efficiency and can condense more quickly. Under the same heat load, the internal components of the required equipment are simpler, and the equipment investment can be significantly reduced. Compared with the indirect wall condensation in the related technology, this efficient mixing condensation method can significantly increase the heat transfer coefficient and make the condensation process more rapid and efficient. In addition, the present disclosure optimizes the operation process during the operation of the carbon dioxide energy storage system, can improve the reliability of the operation of the carbon dioxide energy storage system, and improve the efficiency and energy utilization rate of the energy storage system; it can also reduce the floor area of the equipment, reduce the equipment cost of the entire energy storage system, and facilitate the popularization and use of the gas-liquid phase change carbon dioxide energy storage system.

[0096] In the third embodiment of the present disclosure, refer to Figure 10 , in the energy release stage, the heat exchange medium is the heat supply medium. In other words, the heat exchange module 32 is used to flow in the heat supply medium to evaporate the liquid carbon dioxide in the energy release stage. In the energy storage stage, the heat exchange medium is the heat absorption medium. In other words, the heat exchange module 32 is used to flow in the heat absorption medium to condense the gaseous carbon dioxide in the energy release stage, so that the gaseous carbon dioxide phase changes into liquid subcooled carbon dioxide. It can be understood that the heat exchange module 32 can not only make the gaseous carbon dioxide condense into liquid subcooled carbon dioxide in the energy storage stage, but also make the liquid carbon dioxide further transform into liquid subcooled carbon dioxide.

[0097] In this example, the spraying structure further includes a subcooler 44. The subcooler 44 is disposed on the spraying pipe 33, and the subcooler 44 is located between the spraying liquid pump 34 and the liquid outlet of the liquid storage container 31 (of course, in other examples, the subcooler 44 can also be located between the spraying liquid pump 34 and the spraying head 35). The subcooler 44 is configured to further reduce the temperature of the liquid subcooled carbon dioxide flowing through it. In other words, the subcooler 44 is configured to subcool the liquid subcooled carbon dioxide flowing through it further. The spraying liquid pump 34 is configured to convey the liquid subcooled carbon dioxide to the inlet of the spraying head 35 through the spraying pipe 33. A seventh valve 19 is provided between the spraying liquid pump 34 and the subcooler 44 on the spraying pipe 33, and the seventh valve 19 is used to adjust and control the flow rate of the liquid subcooled carbon dioxide flowing through it. Wherein, the liquid subcooled carbon dioxide is liquid carbon dioxide whose temperature is lower than the dew point of the gaseous carbon dioxide in the spraying area RP.

[0098] In this embodiment, during the energy storage stage of the carbon dioxide energy storage system in the present disclosure, the liquid subcooled carbon dioxide flowing through the spraying pipe 33 is secondarily subcooled by the subcooler, further reducing the temperature of the liquid subcooled carbon dioxide and further improving the condensation efficiency.

[0099] In this embodiment, in the method of using the carbon dioxide energy storage system in the present disclosure, the process during the energy storage stage is as follows:

[0100] Open the second valve 11, the first valve 10, the third valve 12, and the seventh valve 19, and close the fifth valve 16, the fourth valve 14, and the sixth valve 15; the low-temperature and low-pressure gaseous carbon dioxide in the gas storage device 100 is compressed by the compressor 21 and becomes high-temperature and high-pressure gaseous carbon dioxide, then enters the energy storage heat exchanger 22. The energy storage heat exchanger 22 exchanges heat with the low-temperature medium in the cold storage tank 23, transfers the heat of the high-temperature and high-pressure gaseous carbon dioxide in the energy storage heat exchanger 22 to the low-temperature medium, converts the high-temperature and high-pressure gaseous carbon dioxide into low-temperature and high-pressure gaseous carbon dioxide, and makes the low-temperature medium in the cold storage tank 23 become a high-temperature medium and store it in the heat storage tank 24. The low-temperature and high-pressure gaseous carbon dioxide enters the liquid storage container 31, and an endothermic medium is introduced into the heat exchange module 32. The endothermic medium exchanges heat with the liquid carbon dioxide in the liquid storage container 31, so that the liquid carbon dioxide forms liquid subcooled carbon dioxide (or the endothermic medium exchanges heat with the gaseous carbon dioxide entering the liquid storage container 31, so that the gaseous carbon dioxide condenses into liquid carbon dioxide, and the liquid carbon dioxide continues to exchange heat with the endothermic medium, so that the liquid carbon dioxide forms liquid subcooled carbon dioxide). The spray liquid pump 34 extracts the liquid subcooled carbon dioxide in the liquid storage container 31, and after being subcooled again by the subcooler 44, sprays it through the spray head 35 in the spray area RP of the liquid storage container 31. The gaseous carbon dioxide entering the liquid storage container 31 directly mixes and contacts with the liquid subcooled carbon dioxide, so that the low-temperature and high-pressure gaseous carbon dioxide condenses into low-temperature and high-pressure liquid carbon dioxide and is stored in the liquid storage container 31.

[0101] Based on the above three embodiments, refer to Figures 7 - 10 , the storage device 300 further includes a liquid replenishing tank 36, and the liquid replenishing tank 36 stores liquid carbon dioxide (the liquid carbon dioxide stored in the liquid replenishing tank 36 can be injected through other devices, and a valve is provided at the injection port). In one example, the liquid replenishing tank 36 is connected to the liquid storage container 31, and the liquid replenishing tank 36 is used to replenish liquid carbon dioxide into the liquid storage container 31 during the energy storage stage. In one example, the liquid replenishing tank 36 is communicated with the liquid storage container 31 through a liquid replenishing pipe 37, and liquid carbon dioxide can be replenished into the liquid storage container 31 through the liquid replenishing pipe 37. In this way, by pre-supplementing liquid carbon dioxide into the liquid storage container 31 for subcooled spraying, the conversion efficiency of gaseous carbon dioxide is improved (at this time, there is no need to retain liquid carbon dioxide in the liquid storage container 31, which can increase the storage space of subsequent liquid carbon dioxide). In this example, the liquid replenishing pipe 37 is communicated with the lower end of the liquid storage container 31, and liquid carbon dioxide is replenished into the liquid storage container 31 from bottom to top, which can reduce the influence caused by vibration.

[0102] In this example, the position of the liquid replenishing tank 36 can be higher than that of the liquid storage container 31. In this way, it is convenient for the liquid carbon dioxide in the liquid replenishing tank 36 to enter the liquid storage container 31 under the action of gravity. In this example, the end of the liquid replenishing pipe 37 communicating with the liquid replenishing tank 36 is not lower than the end of the liquid replenishing pipe 37 communicating with the liquid storage container 31. An eighth valve 26 is provided on the liquid replenishing pipe 37 (the eighth valve 26 is used to adjust and control the flow rate of the liquid carbon dioxide entering the liquid storage container 31 from the liquid replenishing tank 36). In this way, without setting a liquid pump, the liquid carbon dioxide in the liquid replenishing tank 36 can flow into the liquid storage container 31 under the action of gravity. In one example, the end of the liquid replenishing pipe 37 communicating with the liquid replenishing tank 36 is higher than the end of the liquid replenishing pipe 37 communicating with the liquid storage container 31.

[0103] In one example, a driving pump (not shown in the figure) can also be provided on the liquid replenishing pipe 37, and the driving pump can be used to transfer the liquid carbon dioxide (for example, transfer the liquid carbon dioxide in the liquid replenishing tank 36 to the liquid storage container 31. Another example is to transfer the liquid carbon dioxide in the liquid storage container 31 to the liquid replenishing tank 36). In this way, the liquid replenishing tank 36 can be reused as a liquid storage tank to store the liquid carbon dioxide and increase the storage space of the liquid carbon dioxide.

[0104] Based on the provided liquid replenishing tank 36 and liquid replenishing pipe 37, in the first working mode (energy storage stage), the eighth valve 26 is opened, and the liquid carbon dioxide in the liquid replenishing tank 36 first enters the liquid storage container 31 for subcooling of the liquid carbon dioxide.

[0105] In another example, the liquid replenishing tank 36 can also be directly connected to the spray pipe 33 (not shown in the figure) to provide the liquid carbon dioxide required by the subcooler 44 of the spray structure.

[0106] Based on the above embodiments, refer to Figure 9 And Figure 10, the storage device 300 further includes an auxiliary liquid storage structure; the auxiliary liquid storage structure includes an auxiliary liquid storage tank 38, a first liquid storage pipe 39, a second liquid storage pipe 40, and a liquid storage pump 43. In one example, the first end of the first liquid storage pipe 39 communicates with the liquid storage area RC of the liquid storage container 31, the second end of the first liquid storage pipe 39 communicates with the auxiliary liquid storage tank 38, a ninth valve 27 is provided on the first liquid storage pipe 39, the first end of the second liquid storage pipe 40 communicates with the auxiliary liquid storage tank 38, the second end of the second liquid storage pipe 40 communicates with the liquid storage container 31 (forming a closed-loop structure), the liquid storage pump 43 is provided on the second liquid storage pipe 40, and a tenth valve 28 is provided on the second liquid storage pipe 40 between the liquid storage pump 43 and the auxiliary liquid storage tank 38. In this example, the position of the auxiliary liquid storage tank 38 is lower than the position of the liquid storage container 31 (setting the position of the auxiliary liquid storage tank 38 lower than the position of the liquid storage container 31 can eliminate the need to provide a liquid pump on the first liquid storage pipe 39, and only utilize gravity to transfer liquid carbon dioxide from the liquid storage container 31 into the auxiliary liquid storage tank 38). In this example, the first end of the first liquid storage pipe 39 is lower than the heat exchange module 32. In the present disclosure, providing the auxiliary liquid storage tank 38 can increase the storage capacity (increase the storage space for liquid carbon dioxide). When more liquid carbon dioxide is formed during the energy storage stage, the ninth valve 27 can be opened to transfer the liquid carbon dioxide in the liquid storage container 31 into the auxiliary liquid storage tank 38 for storage. During the energy release stage, the tenth valve 28 is opened, and the liquid storage pump 43 is used to pump the liquid carbon dioxide in the auxiliary liquid storage tank 38 into the liquid storage container 31. Of course, in other examples, the liquid storage container 31 may not store liquid carbon dioxide, and only the auxiliary liquid storage tank 38 stores liquid carbon dioxide (liquid carbon dioxide enters the auxiliary liquid storage tank 38 through the liquid storage container 31 for storage). In another example, the liquid storage pump 43 may also be provided on the first liquid storage pipe 39.

[0107] In one embodiment of the present disclosure, the heat supply medium may be heated water, and the heat absorption medium may be chilled water.

[0108] Those skilled in the art will readily conceive of other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include known common knowledge or conventional technical means in the technical field not disclosed in the present disclosure. The specification and examples are only to be considered as exemplary, and the true scope and spirit of the present disclosure are pointed out by the appended claims.

Claims

1. A storage device for a carbon dioxide energy storage system, characterized in that, Comprising: A liquid storage container, the internal cavity of the liquid storage container includes a spraying area located in the upper part and a liquid storage area located in the lower part; the liquid storage container has at least one gaseous carbon dioxide interface in the spraying area; A heat exchange module, located in the liquid storage area; the inlet and outlet of the heat exchange module both extend outside the liquid storage container; the heat exchange module is at least used to flow in a heat supply medium to evaporate liquid carbon dioxide during the energy release stage; A spraying structure, including a spraying pipe and a spraying head; one end of the spraying pipe is communicated with the liquid storage area of the liquid storage container, and the other end is communicated with the spraying head; the spraying head is used to spray liquid supercooled carbon dioxide into the spraying area during the energy storage stage, and the liquid supercooled carbon dioxide is liquid carbon dioxide with a temperature lower than the dew point of the gaseous carbon dioxide in the spraying area.

2. The storage device of the carbon dioxide energy storage system according to claim 1, characterized in that, The spraying structure further includes a spraying liquid pump and a subcooler; The spraying liquid pump and the subcooler are both arranged on the spraying pipe, and the subcooler is configured to reduce the temperature of the liquid carbon dioxide flowing through it.

3. The storage device of the carbon dioxide energy storage system according to claim 1, wherein The heat exchange module is further used to flow in a heat absorption medium to cool liquid carbon dioxide during the energy storage stage; The spraying structure further includes a spraying liquid pump; the spraying liquid pump is arranged on the spraying pipe.

4. The storage device of the carbon dioxide energy storage system according to claim 1, characterized in that, The storage device further includes a liquid replenishing tank; the liquid replenishing tank is communicated with the liquid storage container through a liquid replenishing pipe; The liquid replenishing tank is used to replenish liquid carbon dioxide to the liquid storage container.

5. The storage device of the carbon dioxide energy storage system according to claim 4, characterized in that, The position of the liquid replenishing tank is higher than the position of the liquid storage container, and one end of the liquid replenishing pipe connected to the liquid replenishing tank is not lower than one end of the liquid replenishing pipe connected to the liquid storage container.

6. The storage device of the carbon dioxide energy storage system according to claim 4, characterized in that, A driving pump is arranged on the liquid replenishing pipe; The driving pump is at least configured to be able to transfer at least part of the liquid carbon dioxide in the liquid storage container into the liquid replenishing tank.

7. The storage device of the carbon dioxide energy storage system according to any one of claims 1-6, characterized in that, The storage device further includes an auxiliary liquid storage structure; The auxiliary liquid storage structure includes an auxiliary liquid storage tank; the inlet of the auxiliary liquid storage tank is communicated with the liquid outlet of the liquid storage container through a first liquid storage pipe, and the outlet of the auxiliary liquid storage tank is communicated with the liquid inlet of the liquid storage container through a second liquid storage pipe, and at least one of the first liquid storage pipe and the second liquid storage pipe is provided with a liquid storage pump.

8. The storage device of the carbon dioxide energy storage system according to claim 1, characterized in that, The heat exchange module is a heat exchange pipe.

9. A carbon dioxide energy storage system, characterized in that, Including the storage device according to any one of claims 1-8.

10. A working method of the storage device according to any one of claims 1-8, characterized in that, Including: During the energy storage stage, spraying liquid supercooled carbon dioxide to condense gaseous carbon dioxide; During the energy release stage, flowing in a heat supply medium to evaporate liquid carbon dioxide.

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