Carbon dioxide energy storage system, storage device thereof, and control method of storage device

Abstract

The present disclosure provides a carbon dioxide energy storage system, a storage device, and a control method for the storage device. These systems relate to the field of carbon dioxide energy storage technology. The storage device includes a liquid storage container, a spraying device, and a heat exchange unit located outside the liquid storage container. The internal cavity of the liquid storage container includes a condensation zone and a storage zone. The condensation zone has a gaseous carbon dioxide inlet, and the storage zone has a first liquid carbon dioxide outlet. The heat exchange unit includes a heat exchange structure, a first connecting pipe, and a second connecting pipe. The heat exchange structure has a first liquid carbon dioxide inlet, a second liquid carbon dioxide outlet, and a gaseous carbon dioxide outlet, and the first liquid carbon dioxide inlet is connected to the first liquid carbon dioxide outlet via a first connecting pipe. The spraying device is disposed in the condensation zone of the liquid storage container, and the second liquid carbon dioxide outlet is connected to the spraying device via a second connecting pipe. This storage device can reduce the number of devices and improve condensation efficiency and condensation conversion rate.

Description

Technical Field

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

[0002] The working process of the carbon dioxide energy storage system includes the energy storage stage and the energy release stage. In the energy storage stage, the condenser is used to condense and liquefy the gaseous carbon dioxide, so that the gaseous carbon dioxide changes into liquid carbon dioxide and is stored; in the energy release stage, the evaporator is used to heat the stored liquid carbon dioxide, so that the liquid carbon dioxide changes into gaseous carbon dioxide and is stored.

[0003] In the related art, the carbon dioxide energy storage system needs to be equipped with a condenser and an evaporator separately, resulting in high system costs.

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

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

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

[0007] A liquid storage container, wherein the internal cavity thereof comprises a condensation zone located at an upper portion and a storage zone located at a lower portion; the liquid storage container has a gaseous carbon dioxide inlet at the condensation zone and a first liquid carbon dioxide outlet at the storage zone;

[0008] a heat exchange unit located outside the liquid storage container; the heat exchange unit comprises a heat exchange structure, a first connecting pipe, and a second connecting pipe; the heat exchange structure has a first liquid carbon dioxide inlet, a second liquid carbon dioxide outlet, and a gaseous carbon dioxide outlet, the first liquid carbon dioxide inlet being connected to the first liquid carbon dioxide outlet via the first connecting pipe;

[0009] a spraying device, disposed in the condensation area of ​​the liquid storage container; the second liquid carbon dioxide outlet is connected to the spraying device through the second connecting pipe;

[0010] The heat exchange unit is configured to allow the liquid carbon dioxide in the liquid storage container to flow into the heat exchange structure during the energy storage stage, and to form liquid supercooled carbon dioxide after heat exchange with the refrigerant medium circulating in the heat exchange structure, and to be pumped into the spraying device; and is configured to allow the liquid carbon dioxide in the liquid storage container to flow into the heat exchange structure during the energy release stage, and to evaporate into gaseous carbon dioxide after heat exchange with the heating medium circulating in the heat exchange structure, and to be exported through the gaseous carbon dioxide outlet.

[0011] In the present disclosure, a new method for achieving condensation of gaseous carbon dioxide is proposed. Liquid carbon dioxide is first supercooled to form liquid supercooled carbon dioxide, and then the liquid supercooled carbon dioxide and gaseous carbon dioxide are directly contacted and mixed to achieve phase change of the gaseous carbon dioxide and condensation into liquid carbon dioxide. The liquid supercooled carbon dioxide still remains in a liquid state (the liquid supercooled carbon dioxide is converted into liquid carbon dioxide, or remains in a liquid supercooled carbon dioxide state). The liquid carbon dioxide formed by the phase change of the gaseous carbon dioxide can continuously participate in the condensation cycle process during the energy storage stage.

[0012] Compared with the existing technology, firstly, the present disclosure adopts a method of direct contact and mixing of liquid supercooled carbon dioxide and gaseous carbon dioxide, which can greatly improve the condensation efficiency; secondly, the present disclosure integrates the supercooling of liquid carbon dioxide and the evaporation of liquid carbon dioxide in a heat exchange unit, and uses a spraying device to spray liquid supercooled carbon dioxide, and integrates the condensation process and storage function in a liquid storage container, which reduces the number of equipment, reduces cost and power consumption; finally, the present disclosure arranges the heat exchange unit outside the liquid storage container, which can realize the flexible setting of the heat exchange unit and facilitate maintenance, and can make the inside of the liquid storage container have more space for the condensation of gaseous carbon dioxide and the storage of liquid carbon dioxide. Under this condition, smaller size or fewer number of liquid storage containers can be set according to demand, which is conducive to cost control.

[0013] In one embodiment of the present disclosure, the heat exchange structure is positioned lower than the liquid storage container. In the present disclosure, by positioning the heat exchange structure lower than the liquid storage container, at least during the energy release phase (evaporation of liquid carbon dioxide), the liquid carbon dioxide in the liquid storage container can be transferred to the heat exchange structure under the action of gravity, thereby saving power.

[0014] In one embodiment of the present disclosure, the first connecting pipe has a first sub-pipe and a second sub-pipe; the heat exchange unit further includes a first driving pump;

[0015] Both ends of the first sub-pipeline and both ends of the second sub-pipeline are connected to the first liquid carbon dioxide outlet and the first liquid carbon dioxide inlet respectively;

[0016] The first driving pump is arranged on the first sub-pipeline. In the present disclosure, an independent first sub-pipeline and a second sub-pipeline are arranged, and the first driving pump is arranged on the first sub-pipeline, which can realize the switching between the energy storage stage and the energy release stage by quickly switching the circulation path of the liquid carbon dioxide, thereby saving power consumption; in the energy storage stage, under the action of the first driving pump, the liquid carbon dioxide inside the liquid storage container is transferred to the heat exchange structure through the first sub-pipeline, and after heat exchange with the refrigerant medium circulating in the heat exchange structure, liquid supercooled carbon dioxide is formed. Under the continuous action of the first driving pump, the liquid supercooled carbon dioxide is transferred from the heat exchange structure through the second connecting pipe to the spraying device, and the spraying device sprays the liquid supercooled carbon dioxide to condense the gaseous carbon dioxide; in the energy release stage, the liquid carbon dioxide inside the liquid storage container is transferred to the heat exchange structure through the second sub-pipeline under the action of gravity, and after heat exchange with the heating medium circulating in the heat exchange structure, gaseous carbon dioxide is formed and flows out from the gaseous carbon dioxide outlet.

[0017] In one embodiment of the present disclosure, the heat exchange structure has a heat exchange medium inlet and a heat exchange medium outlet, the heat exchange medium inlet has a first sub-inlet and a second sub-inlet; the heat exchange medium outlet has a first sub-outlet and a second sub-outlet;

[0018] During the energy release phase, the heating medium flows in through the first sub-inlet and out through the first sub-outlet; during the energy storage phase, the cooling medium flows in through the second sub-inlet and out through the second sub-outlet. In the present disclosure, a second sub-inlet and a second sub-outlet are provided for the cooling medium, and a first sub-inlet and a first sub-outlet are provided for the heating medium. Rapid switching between the energy storage phase and the energy release phase can be achieved by rapidly controlling the opening and closing of the first sub-inlet, the first sub-outlet, the second sub-inlet, and the second sub-outlet.

[0019] In one embodiment of the present disclosure, the heat exchange medium inlet is located higher than the heat exchange medium outlet, thereby ensuring the refrigeration effect and evaporation effect of the liquid carbon dioxide.

[0020] In one embodiment of the present disclosure, the storage device further includes a storage unit for storing liquid carbon dioxide, connected to the storage area of ​​the liquid storage container. The provision of the storage unit in the present disclosure can increase the storage space for liquid carbon dioxide, balance the pressure within the liquid storage container, and reduce power consumption.

[0021] In one embodiment of the present disclosure, the storage unit is connected to the storage area of ​​the liquid storage container via a transfer pipe;

[0022] The transfer pipe is provided with a second drive pump, and the second drive pump is at least configured to transfer at least part of the liquid carbon dioxide in the storage unit to the liquid storage container. In the present disclosure, the second drive pump is provided to realize the mutual transfer of liquid carbon dioxide between the storage unit and the liquid storage container. In this way, during the energy storage stage, liquid carbon dioxide for condensation may not be retained inside the liquid storage container, or when the liquid carbon dioxide retained inside the liquid storage container is insufficient to support the condensation cycle, the liquid carbon dioxide in the storage unit can be directly transferred to the liquid storage container through the second drive pump. In this way, the space of the condensation zone can be increased to the greatest extent.

[0023] In one embodiment of the present disclosure, the upper end of the storage unit is connected to the second connecting pipe and the gaseous carbon dioxide inlet. In the present disclosure, connecting the upper end of the storage unit, the second connecting pipe, and the gaseous carbon dioxide inlet can balance the pressure of the entire storage device, reduce power consumption, and ensure stable operation of the storage device.

[0024] According to another aspect of the present disclosure, a carbon dioxide energy storage system is provided, comprising the storage device of the carbon dioxide energy storage system.

[0025] According to another aspect of the present disclosure, a method for controlling a storage device of a carbon dioxide energy storage system is provided, comprising:

[0026] Energy storage stage:

[0027] The liquid carbon dioxide in the liquid storage container flows into the heat exchange structure and forms liquid supercooled carbon dioxide after heat exchange with the refrigerant flowing in the heat exchange structure. The liquid supercooled carbon dioxide is then pumped into the spraying device. The spraying device sprays the liquid supercooled carbon dioxide in the condensation area. The liquid supercooled carbon dioxide directly mixes and contacts with the gaseous carbon dioxide entering the liquid storage container, thereby completing the condensation of the gaseous carbon dioxide.

[0028] Energy release stage:

[0029] Liquid carbon dioxide in the liquid storage container flows into the heat exchange structure and, after heat exchange with the heat supply medium flowing through the heat exchange structure, evaporates into gaseous carbon dioxide and exits through the gaseous carbon dioxide outlet. This disclosure provides a new method for condensing gaseous carbon dioxide. Compared to existing technologies, this method utilizes direct contact mixing of liquid supercooled carbon dioxide and gaseous carbon dioxide, significantly improving condensation efficiency and reducing power consumption.

[0030] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the specification, are used to explain the principles of the present disclosure. Obviously, the drawings described below are only some embodiments of the present disclosure, and those skilled in the art can derive other drawings based on these drawings without inventive effort.

[0032] Figure 1 This is a schematic diagram of a carbon dioxide energy storage system in one embodiment of the present disclosure.

[0033] Figure 2 This is a schematic diagram of a carbon dioxide energy storage system in one embodiment of the present disclosure.

[0034] Figure 3 This is a schematic diagram of a carbon dioxide energy storage system in one embodiment of the present disclosure.

[0035] Figure 4 This is a schematic diagram of a storage device in one embodiment of the present disclosure.

[0036] Figure 5 This is a schematic diagram of a carbon dioxide energy storage system in one embodiment of the present disclosure.

[0037] Figure 6 This is a schematic diagram of a storage device in one embodiment of the present disclosure.

[0038] Figure 7 This is a schematic diagram of a carbon dioxide energy storage system in one embodiment of the present disclosure. DETAILED DESCRIPTION

[0039] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in many 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 concepts of the example embodiments to those skilled in the art. Like reference numerals in the figures represent identical or similar structures, and thus their detailed descriptions will be omitted. Furthermore, the figures are merely 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 relationship of one illustrated component to another, these terms are used herein for convenience only, such as in accordance with the orientation of the illustrations in the accompanying drawings. It will be understood that if the illustrated device were flipped upside down, the component described as "upper" would become the component "lower." When a structure is referred to as "on" another structure, this may mean that the structure is integrally formed with the other structure, that the structure is "directly" disposed on the other structure, or that the structure is "indirectly" disposed on the other structure via the other structure.

[0041] The terms "a", "an", "the", and "said" are used to indicate the presence of one element / component / etc.; the terms "including" and "having" are used to express open-ended inclusion and mean that additional elements / components / etc. may exist in addition to the listed elements / components / etc.; the terms "first", "second", and "third" etc. are used only as labels and are not intended to limit the quantity of their objects.

[0042] The present disclosure provides a carbon dioxide energy storage system. Figure 1 The carbon dioxide energy storage system includes a gas storage device 100, and a sequentially connected energy storage assembly 200, a storage device 300, and an energy release assembly 400. The gas storage device 100 is connected to the inlet of the energy storage assembly 200, the outlet of the energy storage assembly 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 assembly 400, and the outlet of the energy release assembly 400 is connected to the gas storage device 100. The gas storage device 100 can store gaseous carbon dioxide, for example, low-temperature, low-pressure gaseous carbon dioxide; the storage device 300 can condense gaseous carbon dioxide, store, and evaporate liquid carbon dioxide. The energy storage assembly 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 the compressed gaseous carbon dioxide, for example, cooling the compressed gaseous carbon dioxide until it condenses into liquid carbon dioxide for storage, or allowing the cooled gaseous carbon dioxide to enter the storage device 300 to be condensed into liquid carbon dioxide for storage. The storage device 300 can also heat the stored liquid carbon dioxide, for example, by evaporating the liquid carbon dioxide stored in the storage device 300 into gaseous carbon dioxide and then sending it to the energy release component 400. The energy release component 400 heats the gaseous carbon dioxide and causes the heated gaseous carbon dioxide to expand and generate electricity.

[0043] For example, during the energy storage phase, the energy storage assembly 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, thereby converting the gaseous carbon dioxide into liquid carbon dioxide and storing it in the storage device 300. During the energy release phase, the storage device 300 can evaporate the liquid carbon dioxide stored therein into gaseous carbon dioxide, and the energy release assembly 400 can expand the gaseous carbon dioxide from the storage device 300 to generate electricity, thereby storing the expanded gaseous carbon dioxide in the gas storage device 100.

[0044] In one embodiment of the present disclosure, the gas storage device 100 may be a gas storage tank. In the present disclosure, the inlet and outlet of the gas storage device 100 may be shared. In one example, the gas storage device 100 may have an interface that can be connected to a T-shaped pipe, with control valves provided at the other ends of the T-shaped pipe, respectively, serving as the inlet and outlet.

[0045] In one embodiment of the present disclosure, see Figure 2 The energy storage assembly 200 includes at least one compressed energy storage unit 201; the compressed energy storage unit 201 includes a compressor 21 and an energy storage heat exchanger 22. Each compressed energy storage unit 201 is connected to the gas storage device 100 and the storage device 300. Specifically, the inlet of each compressed energy storage unit 201 is connected to the gas storage device 100, and the outlet of each compressed energy storage unit 201 is connected to the storage device 300. The compressor 21 can be driven by electricity to compress the gaseous carbon dioxide from the gas storage device 100, compressing the low-temperature and low-pressure gaseous carbon dioxide into high-temperature and high-pressure gaseous carbon dioxide. The compressed carbon dioxide can be heat exchanged and cooled in the energy storage heat exchanger 22. After heat exchange and cooling in the energy storage heat exchanger 22, the high-temperature and high-pressure gaseous carbon dioxide forms a low-temperature and high-pressure gaseous carbon dioxide.

[0046] exist Figure 2 In the example, the energy storage assembly 200 includes three compressed energy storage units 201. It is understood that in other embodiments of the present disclosure, the number of compressed energy storage units 201 in the energy storage assembly 200 is not limited to three, and can be, for example, one, or a plurality of other numbers (e.g., two, four, five, or six).

[0047] In one embodiment of the present disclosure, the compression energy storage section 201 includes a compression energy storage unit or a plurality of compression energy storage units cascaded in sequence. A compression energy storage unit may include a compressor 21 and an 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 and cooling. When the compression energy storage section 201 includes a plurality of compression energy storage units cascaded in sequence, between two adjacent compression energy storage units, the carbon dioxide outlet of the energy storage heat exchanger 22 of the upper-stage compression energy storage unit is connected to the inlet of the compressor 21 of the lower-stage compression energy storage unit. Figure 2 In the example of FIG, the compressed energy storage unit 201 includes two compressed energy storage units. It is understandable that, as needed, the compressed energy storage unit in the compressed energy storage unit 201 can be one, two, or more than two.

[0048] exist Figure 2 In the example, solid arrows indicate the flow direction of carbon dioxide in the compressed energy storage unit 201, and dashed arrows indicate the flow direction of the cooling medium through the energy storage heat exchanger 22. In the energy storage heat exchanger 22, the compressed carbon dioxide, which has a higher temperature, exchanges heat with the cooling medium, which has a lower temperature. This cools the carbon dioxide, facilitating its condensation into liquid carbon dioxide. The cooling medium absorbs heat and increases its temperature, recovering the heat generated during the compression of the carbon dioxide.

[0049] In one 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 is understood that when the compression energy storage unit 201 has only one compression energy storage unit, the inlet of the compressor 21 of the compression energy storage unit 201 is connected to the gas storage device 100. For further information, see Figure 5 and Figure 7 A second valve 11 may be provided between the inlet of the first stage compressor 21 and the gas storage device 100. The second valve 11 is used to adjust and control the flow of gaseous carbon dioxide passing therethrough. Figure 5 and Figure 7 In the illustrated carbon dioxide energy storage system, only the first-stage compressor 21 of the compression energy storage unit 201 is shown. Each compressor 21 represents a corresponding compression energy storage unit 201 in the carbon dioxide energy storage system.

[0050] In one embodiment of the present disclosure, see Figure 3The energy release assembly 400 includes at least one expansion energy release unit 401. This expansion energy release unit 401 includes a turbine 41 and an energy release heat exchanger 42. 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. Carbon dioxide from the storage device 300 absorbs heat in the energy release heat exchanger 42 before entering the turbine 41, thereby driving the generator G to generate electricity.

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

[0052] In one embodiment of the present disclosure, the expansion energy release section 401 includes one expansion energy release unit or multiple expansion energy release units cascaded in sequence. One expansion energy release unit may include a turbine 41 and an 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 carbon dioxide absorbs heat in the energy release heat exchanger 42, it flows into the turbine 41 to expand and generate electricity. When the expansion energy release section 401 includes multiple expansion energy release units cascaded in sequence, 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. Figure 3 In the example of FIG, the expansion energy release portion 401 includes two expansion energy release units. It is understandable that, as needed, the number of expansion energy release units in the expansion energy release portion 401 can be one, two, or more than two.

[0053] exist Figure 3 In the example, solid arrows indicate the flow direction of carbon dioxide in the expansion and energy release section 401, and dashed arrows indicate the flow direction of the heating medium through the energy release heat exchanger 42. In the energy release heat exchanger 42, the carbon dioxide that has expanded and cooled after flowing out of the storage device 300 exchanges heat with the higher-temperature heating medium, thereby heating the carbon dioxide and recovering the cold energy generated by the expansion of the gaseous carbon dioxide.

[0054] In one embodiment of the present disclosure, the outlet of the last stage turbine 41 of the expansion energy release part 401 is connected to the gas storage device 100. It is understood that when the expansion energy release part 401 has only one expansion energy release unit, the outlet of the turbine 41 of the expansion energy release part 401 is connected to the gas storage device 100. Optionally, see Figure 5 and Figure 7A sixth valve 15 is provided between the outlet of the last stage turbine 41 of the expansion energy release part 401 and the gas storage device 100, wherein the sixth valve 15 acts as a switch valve, which is closed in the energy storage stage and opened in the energy release stage. Figure 5 and Figure 7 In the illustrated carbon dioxide energy storage system, only the last stage turbine 41 of the expansion energy release part 401 is shown, and each turbine 41 represents the existence of a corresponding expansion energy release part 401 .

[0055] It is 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, see Figure 5 and Figure 7 The CO2 energy storage system can also be equipped with a heat recovery assembly, which includes a heat storage tank 24 and a cold storage tank 23. During the energy storage phase, 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). This reduces the temperature of the CO2 in the energy storage heat exchanger 22, heating the low-temperature medium to a high-temperature medium before storing it in the heat storage tank 24. During the energy release phase, 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). This increases the temperature of the CO2 in the energy release heat exchanger 42, cooling the high-temperature medium to a low-temperature medium before storing it 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 temperatures are different.

[0056] In one embodiment of the present disclosure, the compression energy storage unit 201 includes a compression energy storage unit, and the expansion energy release unit 401 includes an expansion energy release unit. Figure 5 and Figure 7 The inlet of the compressor 21 is connected to the outlet of the gas storage device 100 via the third pipe 8, the inlet of the energy storage heat exchanger 22 is connected to the outlet of the compressor 21 via the fourth pipe 9, and the outlet of the energy storage heat exchanger 22 is connected to the storage device 300 via the fifth pipe 20. In this example, the second valve 11 is provided on the third pipe 8.

[0057] In one embodiment of the present disclosure, see Figure 5 and Figure 7The energy storage heat exchanger 22 has a gaseous carbon dioxide outlet and a gaseous carbon dioxide inlet. The outlet of the compressor 21 is connected to the gaseous carbon dioxide inlet of the energy storage heat exchanger 22 via a fourth pipe 9, and the gaseous carbon dioxide outlet of the energy storage heat exchanger 22 is connected to the storage device 300 via a fifth pipe 20. The energy storage heat exchanger 22 also has a first medium inlet and a first medium outlet. The cold storage tank 23 is connected to the first medium inlet via a first pipe 6, and the first medium outlet is connected to the heat storage tank 24 via a second pipe 7. A first circulation pump 25 is provided on the first pipe 6, and a first valve 10 is provided between the first circulation pump 25 and the first medium inlet. In this example, the heat storage tank 24 is used to store high-temperature medium after absorbing heat from the gaseous carbon dioxide, while the cold storage tank 23 is used to store low-temperature medium after releasing heat from 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 regulate and control the flow of the low-temperature medium from the cold storage tank 23 into the energy storage heat exchanger 22.

[0058] In one embodiment of the present disclosure, the low-temperature medium and the high-temperature medium may be water, thermal 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 one embodiment of the present disclosure, the inlet of the energy-releasing heat exchanger 42 is connected to the storage device 300 via a sixth pipeline 1. The outlet of the energy-releasing heat exchanger 42 is connected to the inlet of the turbine 41 via a seventh pipeline 2. The turbine 41 is equipped with a generator G, which is used to convert the mechanical energy generated by the expansion of high-temperature and high-pressure gaseous carbon dioxide within the turbine 41 into electrical energy. The outlet of the turbine 41 is connected to the inlet of the gas storage device 100 via an eighth pipeline 3. The sixth valve 15 is provided on the eighth pipeline 3.

[0060] In one embodiment of the present disclosure, the turbine 41 is used to expand the high-temperature and high-pressure gaseous carbon dioxide to convert it into low-temperature and low-pressure gaseous carbon dioxide, and the generator G is used to convert the mechanical energy generated by the high-temperature and high-pressure gaseous carbon dioxide expanding in the turbine into electrical energy.

[0061] In one embodiment of the present disclosure, see 5 and Figure 7The 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 connected to the gaseous carbon dioxide inlet of the energy-releasing heat exchanger 42 via a sixth pipe 1. The gaseous carbon dioxide outlet of the energy-releasing heat exchanger 42 is connected to the turbine 41 via a seventh pipe 2. The energy-releasing heat exchanger 42 also has a second medium inlet and a second medium outlet. The heat storage tank 24 is connected to the second medium inlet via a ninth pipe 4. The second medium outlet is connected to the cold storage tank 23 via a tenth pipe 5. A second circulation pump 13 is provided on the ninth pipe 4, and a fourth valve 14 is provided between the second circulation pump 13 and the second medium inlet. In this example, second circulating pump 13 is used to transport high-temperature medium to energy-releasing heat exchanger 42; fourth valve 14 is used to regulate and control the flow of high-temperature medium from heat storage tank 24 into energy-releasing heat exchanger 42. Energy-releasing heat exchanger 42 is used to transfer heat from the high-temperature medium in heat storage tank 24 to low-temperature, high-pressure gaseous carbon dioxide, converting it into high-temperature, high-pressure gaseous carbon dioxide. After the high-temperature medium releases heat, its temperature drops to form low-temperature medium, which is stored in cold storage tank 23. In the present disclosure, the same set of cold storage tank 23 and heat storage tank 24 is used to achieve heat recycling between energy storage heat exchanger 22 and energy-releasing heat exchanger 42, which not only improves energy utilization, but also reduces the amount of equipment, simplifies processes and operating methods, and reduces costs.

[0062] exist Figure 4-Figure 7 In the example, there is one storage device 300. It is understood that in the embodiments of the present disclosure, there may be multiple storage devices 300. When there are multiple storage devices 300, these storage devices 300 may be connected in series, in parallel, or in a combination of series and parallel.

[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 and heat exchange structure 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 release unit and the liquid storage container. In other words, the carbon dioxide inlet of the first-stage energy release 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 release heat exchanger.

[0064] In the related art, the condenser and the evaporator in the storage device are independently provided, which makes the cost of the carbon dioxide energy storage system relatively high.

[0065] To solve the above problems, see Figure 4-Figure 7 The present disclosure provides a storage device 300. The storage device 300 realizes an integrated setting of condensation function and evaporation function, etc., which can reduce the number of devices, reduce energy consumption, and reduce costs.

[0066] In one example, see Figure 4-Figure 7 The storage device 300 includes a liquid storage container 33, a heat exchange unit and a spraying device 50.

[0067] In this example, see Figure 4-Figure 7 The liquid storage container 33 has a cavity, which provides space for the condensation phase transition and storage of carbon dioxide, as well as space for the spraying device 50. The cavity is divided from top to bottom into a condensation region RP and a storage region RC (in other words, the cavity includes the condensation region RP located at the top and the storage region RC located at the bottom). In this example, the condensation region RP and the storage region RC can be dynamically adjusted based on the inventory of liquid carbon dioxide in the liquid storage container 33.

[0068] Optionally, a gaseous carbon dioxide inlet is provided on the liquid storage container 33, and the gaseous carbon dioxide inlet is located in the condensation region RP. In other words, see Figure 4-Figure 7 The liquid storage container 33 has a third connecting pipe 37 in the condensation area RP. The end of the third connecting pipe 37 away from the liquid storage container 33 serves as the inlet of gaseous carbon dioxide and is connected to the outlet of the last-stage energy storage heat exchanger 22. A third valve 32 is provided on the third connecting pipe 37, and the opening and closing of the third valve 32 can be used to control the entry of gaseous carbon dioxide into the liquid storage container 33.

[0069] In one embodiment of the present disclosure, see Figure 4-Figure 7 The liquid storage container 33 also has a first liquid carbon dioxide outlet. The first liquid carbon dioxide outlet is located in the storage area RC and at the lower end of the liquid storage container 33.

[0070] In one embodiment of the present disclosure, the heat exchange unit includes a heat exchange structure 34, a first connecting pipe, a second connecting pipe 31, and a first driving pump 51. The heat exchange unit is configured such that, during the energy storage phase, the liquid carbon dioxide in the liquid storage container 33 flows into the heat exchange structure 34, and after heat exchange with the refrigerant medium circulating in the heat exchange structure 34, the liquid supercooled carbon dioxide is formed and pumped into the spraying device 50; and the heat exchange unit is configured such that, during the energy release phase, the liquid carbon dioxide in the liquid storage container 33 flows into the heat exchange structure 34, and after heat exchange with the heating medium circulating in the heat exchange structure 34, the liquid carbon dioxide evaporates into gaseous carbon dioxide and flows out through the gaseous carbon dioxide outlet.

[0071] The heat exchange structure 34 is located outside the liquid storage container 33 and is in communication with the storage area RC of the liquid storage container 33. Liquid carbon dioxide within the liquid storage container 33 can be transferred into the heat exchange structure 34. The heat exchange structure 34 is configured to allow a refrigerant medium to flow into it during the energy storage phase, causing the incoming liquid carbon dioxide to form liquid supercooled carbon dioxide. It is also configured to allow a heating medium to flow into it during the energy release phase, causing the incoming liquid carbon dioxide to evaporate and transform into gaseous carbon dioxide.

[0072] Optionally, the lower end of the heat exchange structure 34 has a first liquid carbon dioxide inlet.

[0073] In one example, there is one first liquid carbon dioxide outlet (not shown), which is connected to the first liquid carbon dioxide inlet via a first connecting pipe. A first drive pump 51 is provided on the first connecting pipe, configured to transfer at least a portion of the liquid carbon dioxide within the liquid storage container 33 to the heat exchange structure 34. In other words, under the action of the first drive pump 51, the liquid carbon dioxide within the liquid storage container 33 can enter the heat exchange structure 34 through the first connecting pipe, exchanging heat with the heating medium or refrigerant flowing into the heat exchange structure 34. In this case, the first liquid carbon dioxide outlet serves as both an outlet for liquid carbon dioxide during the energy release phase and an outlet for liquid carbon dioxide during the energy storage phase. The first connecting pipe serves as a circulation conduit for liquid carbon dioxide during both the energy release phase and the energy storage phase, corresponding to the number of first liquid carbon dioxide inlets being one.

[0074] In another example, participating Figure 4-Figure 7 , the position of the heat exchange structure 34 is lower than that of the liquid storage container 33. When the heat exchange structure 34 is lower than that of the liquid storage container 33, during the energy release phase, the liquid carbon dioxide in the liquid storage container 33 can enter the heat exchange structure 34 under the action of gravity to exchange heat, so that the liquid carbon dioxide continuously evaporates and changes into gaseous carbon dioxide.

[0075] In this example, there are two first liquid carbon dioxide outlets. As will be appreciated, the lower end of the liquid storage container 33 is connected to a main pipe 35. The end of the main pipe 35 remote from the liquid storage container 33 is connected to a fourth connecting pipe 17 and a fifth connecting pipe 18 via a three-way valve. The end of the fourth connecting pipe 17 remote from the main pipe 35 and the end of the fifth connecting pipe 18 remote from the main pipe 35 serve as the two first liquid carbon dioxide outlets. A fifth valve 48 is provided on the fourth connecting pipe 17, and a seventh valve 49 is provided on the fifth connecting pipe 18. By alternately opening and closing the fifth and seventh valves 48 and 49, the flow direction of the liquid carbon dioxide can be controlled.

[0076] In this example, see Figure 4-Figure 7 The first connecting pipe includes a first sub-pipeline 12 and a second sub-pipeline 16. One end of the first sub-pipeline 12 is connected to the fourth connecting pipe 17, and the other end is connected to the first liquid carbon dioxide inlet. One end of the second sub-pipeline 16 is connected to the fifth connecting pipe 18, and the other end is connected to the first liquid carbon dioxide inlet. In one example, a first driving pump 51 is arranged on the first sub-pipeline 12, and is used to transfer liquid carbon dioxide during the energy storage stage (so that the liquid carbon dioxide in the liquid storage container 33 is transferred to the heat exchange structure 34).

[0077] In this example, the first connecting pipe is divided into two sub-pipes (a first sub-pipe 12 and a second sub-pipe 16). During the energy storage phase, the first drive pump 51 can be used to allow the liquid carbon dioxide in the liquid storage container 33 to enter the heat exchange structure 34 through the fourth connecting pipe 17 and the first sub-pipe 12 for heat exchange. During the energy release phase, because the heat exchange structure 34 is located below the liquid storage container 33, the liquid carbon dioxide in the liquid storage container 33 can be transferred to the heat exchange structure 34 under the action of gravity through the fifth connecting pipe 18 and the second sub-pipe 16 for heat exchange. In other words, during the energy release phase, the first drive pump 51 does not perform work, which can reduce power consumption and save costs.

[0078] In one example, the first sub-pipeline 12 and the second sub-pipeline 16 are both connected to the same first liquid carbon dioxide inlet of the heat exchange structure 34. In another example, the first sub-pipeline 12 and the second sub-pipeline 16 can be connected to two first liquid carbon dioxide inlets of the heat exchange structure 34 respectively.

[0079] In one embodiment of the present disclosure, during the energy storage phase, a refrigerant medium flows through the heat exchange structure 34, and during the energy release phase, a heating medium flows through the heat exchange structure 34. In this embodiment, the heat exchange structure 34 has a heat exchange medium inlet and a heat exchange medium outlet.

[0080] In one example, there is only one heat exchange medium inlet and one heat exchange medium outlet. In this example, during the energy release phase, heating medium flows into the heat exchange medium inlet and flows out of the heat exchange medium outlet. During the energy storage phase, cooling medium flows into the heat exchange medium inlet and flows out of the heat exchange medium outlet. In other words, during the energy release and energy storage phases, heating medium and cooling medium flow alternately into the heat exchange medium inlet.

[0081] In another example, see Figure 4-Figure 7The heating medium and the refrigerant medium flow into and out of the heat exchange structure 34 through separate connecting pipes. It is understood that the heat exchange medium inlet has a first sub-inlet and a second sub-inlet, and the heat exchange medium outlet has a first sub-outlet and a second sub-outlet. In this example, a sixth connecting pipe 52 is provided on the circumference of the heat exchange structure 34. The sixth connecting pipe 52 is connected to the seventh connecting pipe 27 and the eighth connecting pipe 28 via a three-way valve. The end of the seventh connecting pipe 27 away from the sixth connecting pipe 52 serves as the first sub-inlet, and the end of the eighth connecting pipe 28 away from the sixth connecting pipe 52 serves as the second sub-inlet. The seventh connecting pipe 27 is provided with an eighth valve 44, and the eighth connecting pipe 28 is provided with a ninth valve 45.

[0082] The heat exchange structure 34 also has a ninth connecting pipe 53 on its circumference. This pipe is connected to the tenth and eleventh connecting pipes 29 and 30 via a three-way valve. The end of the tenth connecting pipe 29, distal from the ninth connecting pipe 53, serves as the first sub-outlet, while the end of the eleventh connecting pipe 30, distal from the ninth connecting pipe 53, serves as the second sub-outlet. A tenth valve 46 is provided on the tenth connecting pipe 29, and an eleventh valve 47 is provided on the eleventh connecting pipe 30. In this example, during the energy discharging phase, heating medium flows in through the first sub-inlet (the seventh connecting pipe 27) and out through the first sub-outlet (the tenth connecting pipe 29). During the energy storage phase, refrigerant medium flows in through the second sub-inlet (the eighth connecting pipe 28) and out through the second sub-outlet (the eleventh connecting pipe 30). This allows the heat exchange structure 34 to rapidly switch between the flow of heating medium during the energy discharging phase and the flow of refrigerant during the energy storage phase simply by controlling the eleventh valve 47, the tenth valve 46, the ninth valve 45, and the eighth valve 44.

[0083] In one embodiment of the present disclosure, the position of the heat exchange medium inlet is higher than the position of the heat exchange medium outlet, so that the heat exchange effect of supercooling or evaporation can be further guaranteed (as the heat exchange continues, the temperature of the refrigerant medium will gradually increase. If the position of the heat exchange medium inlet is lower than the position of the heat exchange medium outlet, then at the heat exchange medium outlet, the refrigerant medium temperature is higher and may exchange heat again with the liquid supercooled carbon dioxide formed through heat exchange at the heat exchange medium inlet, thereby reducing the supercooling of the liquid carbon dioxide and reducing the condensation efficiency. The same applies to the evaporation process of the liquid carbon dioxide).

[0084] In one embodiment of the present disclosure, the heat exchange structure 34 may include at least one heat exchange module, with its ends connected to the ninth connecting pipe 53 and the sixth connecting pipe 52, respectively. A heating medium or a cooling medium circulates within the heat exchange module, exchanging heat with the carbon dioxide within the heat exchange structure 34 through a partitioned heat exchange mechanism. In one example, the heat exchange module is a heat exchange tube, with its inlet communicating with the medium inlet (the sixth connecting pipe 52) and its outlet communicating with the medium outlet (the ninth connecting pipe 53). In other examples, the heat exchange module may be a heat exchange plate. Of course, in other examples, the heat exchange module may also have other structures not shown.

[0085] In one embodiment of the present disclosure, a plurality of heat exchange teeth may be provided on the circumference of the heat exchange module, so as to accelerate the transfer of heat.

[0086] In one embodiment of the present disclosure, the number of heat exchange modules may be one. In other embodiments, the number of heat exchange modules may be multiple, for example, two, four, or five. This can both increase the contact area between carbon dioxide and the heat exchange module, thereby accelerating the phase change conversion efficiency of carbon dioxide, and increase the total flow rate of the heating medium or refrigerant medium entering the heat exchange module, thereby accelerating the phase change conversion efficiency of carbon dioxide.

[0087] In one embodiment of the present disclosure, taking the heat exchange module as an example, the heat exchange tubes can be arranged sequentially along a first direction. This increases the contact area between the carbon dioxide and the heat exchange tubes, thereby accelerating the carbon dioxide conversion efficiency. In another embodiment, the heat exchange tubes can be arranged sequentially along a second direction. This achieves both cross-flow heat exchange (cross-flow heat exchange in this disclosure refers to the direction of carbon dioxide transfer within the heat exchange structure 34 intersecting with the flow direction of the heating medium or refrigerant within the heat exchange tubes) and increases the contact area between the carbon dioxide and the heat exchange tubes, thereby accelerating the carbon dioxide conversion efficiency. In another embodiment, the heat exchange tubes can be arranged simultaneously along the first and second directions. This creates a multi-layered structure, further increasing the contact area between the carbon dioxide and the heat exchange tubes and accelerating the carbon dioxide conversion efficiency. The first direction intersects the second direction. In one example, the first direction refers to the vertical direction of the heat exchange structure 34 (i.e., the direction of carbon dioxide transfer within the heat exchange structure 34), and the first direction is perpendicular to the second direction.

[0088] In one embodiment of the present disclosure, the upper end of the heat exchange structure 34 has a second liquid carbon dioxide outlet and a gaseous carbon dioxide outlet, wherein the gaseous carbon dioxide outlet is connected to the inlet of the energy-releasing heat exchanger 42 in the first stage. During the energy-releasing stage, the liquid carbon dioxide entering the heat exchange structure 34 exchanges heat with the heat supply medium, so that the liquid carbon dioxide evaporates and changes into gaseous carbon dioxide, and flows out of the gaseous carbon dioxide outlet to the energy-releasing heat exchanger 42. The second liquid carbon dioxide outlet is connected to the spraying device 50. During the energy-storing stage, the liquid carbon dioxide entering the heat exchange structure 34 exchanges heat with the refrigerant medium, so that the liquid carbon dioxide is converted into liquid supercooled carbon dioxide, and flows out of the second liquid carbon dioxide outlet to the spraying device 50.

[0089] Optionally, a twelfth connecting pipe 36 is provided at the upper end of the heat exchange structure 34. The twelfth connecting pipe 36 is connected to the thirteenth connecting pipe 26 and the fourteenth connecting pipe 19 via a three-way valve. The end of the thirteenth connecting pipe 26 remote from the twelfth connecting pipe 36 serves as a gaseous carbon dioxide outlet, and the end of the fourteenth connecting pipe 19 remote from the twelfth connecting pipe 36 serves as a second liquid carbon dioxide outlet. A twelfth valve 43 is provided on the thirteenth connecting pipe 26, and a thirteenth valve 55 is provided on the fourteenth connecting pipe 19. The thirteenth connecting pipe 26 is connected to the first-stage energy-releasing heat exchanger 42 via the sixth pipeline 1, and the fourteenth connecting pipe 19 is connected to the spraying device 50 via the second connecting pipe 31. In the energy storage stage, after the liquid carbon dioxide exchanges heat with the refrigerant medium in the heat exchange structure 34, the formed liquid supercooled carbon dioxide passes through the twelfth connecting pipe 36, the fourteenth connecting pipe 19, and the second connecting pipe 31 in sequence and then enters the spraying device 50; in the energy release stage, after the liquid carbon dioxide exchanges heat with the heating medium in the heat exchange structure 34, the formed gaseous carbon dioxide passes through the twelfth connecting pipe 36 and the thirteenth connecting pipe 26 in sequence and then enters the energy release heat exchanger 42.

[0090] In one embodiment of the present disclosure, there may be two twelfth connecting pipes 36 , which are connected to the thirteenth connecting pipe 26 and the fourteenth connecting pipe 19 respectively.

[0091] In one embodiment of the present disclosure, see Figure 4-Figure 7The spraying device 50 is configured to spray the liquid supercooled carbon dioxide flowing into the condensation zone RP. The spraying device 50 includes a spray head (only a schematic structure is shown in the figure). The spray head is located in the condensation zone RP of the liquid storage container 33 and can spray the liquid supercooled carbon dioxide flowing therein. In the present disclosure, the condensation of the gaseous carbon dioxide is achieved by directly mixing and contacting the liquid supercooled carbon dioxide with the gaseous carbon dioxide. (The liquid supercooled carbon dioxide has a relatively low temperature and a certain degree of subcooling compared to its saturation temperature. Therefore, during the heat exchange process, the gaseous carbon dioxide entering the liquid storage container 33 can be condensed while maintaining its liquid phase. In other words, the gaseous carbon dioxide and the liquid supercooled carbon dioxide directly mix and contact, exchanging heat, causing the gaseous carbon dioxide to condense and transform into liquid carbon dioxide. The liquid supercooled carbon dioxide then forms liquid carbon dioxide or remains in the liquid supercooled carbon dioxide state.) In other words, the liquid supercooled carbon dioxide directly contacts and mixes with the low-temperature, high-pressure gaseous carbon dioxide continuously entering the liquid storage container 33, achieving a rapid phase transition from gaseous carbon dioxide to liquid carbon dioxide, thereby completing the carbon dioxide condensation process. The condensation efficiency of this condensation method is much higher than that of the existing partition wall condensation process. In which, the liquid supercooled carbon dioxide is liquid carbon dioxide with a temperature lower than the dew point of the gaseous carbon dioxide in the condensation zone RP.

[0092] In one embodiment, the spray head is located at the upper end of the liquid storage container 33, and the gaseous carbon dioxide inlet is located at the upper end of the liquid storage container 33. In this way, the time for direct mixing and contact between the gaseous carbon dioxide and the liquid supercooled carbon dioxide can be extended, so that the gaseous carbon dioxide and the liquid supercooled carbon dioxide can fully contact each other, thereby improving the condensation efficiency of the gaseous carbon dioxide.

[0093] The present disclosure does not limit the structure of the spraying device 50. Figure 4-Figure 7 In the figure, only the structure of the spraying device 50 is illustrated. The spraying device 50 may have a plurality of spraying heads so that the spraying device 50 uniformly sprays the liquid supercooled carbon dioxide in the condensation region RP.

[0094] In one embodiment of the present disclosure, the heating medium may be heating water, and the cooling medium may be chilled water.

[0095] Based on the storage device provided in the present disclosure, the present disclosure also provides a method for controlling the storage device, including:

[0096] Energy storage stage:

[0097] The liquid carbon dioxide in the liquid storage container 33 flows into the heat exchange structure 34 and forms liquid supercooled carbon dioxide after heat exchange with the refrigerant flowing in the heat exchange structure 34. The carbon dioxide is then pumped into the spraying device 50. The spraying device 50 sprays the liquid supercooled carbon dioxide in the condensation area RP. The liquid supercooled carbon dioxide directly mixes with the gaseous carbon dioxide entering the liquid storage container 33, thereby completing the condensation of the gaseous carbon dioxide.

[0098] Specifically, the third valve 32, the fifth valve 48, the ninth valve 45, the eleventh valve 47, and the thirteenth valve 55 are opened, and the twelfth valve 43, the eighth valve 44, the tenth valve 46, and the seventh valve 49 are closed. The first driving pump 51 is started, and low-temperature, high-pressure gaseous carbon dioxide enters the liquid storage container 33. The first driving pump 51 transfers liquid carbon dioxide in the liquid storage container 33 (which may be liquid carbon dioxide pre-stored in the liquid storage container 33) into the heat exchange structure 34. A refrigerant is introduced into the heat exchange structure 34. The refrigerant exchanges heat with the liquid carbon dioxide entering the heat exchange structure 34, causing the liquid carbon dioxide to form liquid supercooled carbon dioxide. Under the continuous operation of the first driving pump 51, the liquid supercooled carbon dioxide overcomes gravity and resistance along the pipeline and is transferred to the spraying device 50. The spray head sprays the supercooled carbon dioxide into the condensation area RP of the liquid storage container 33. The gaseous carbon dioxide entering the liquid storage container 33 directly mixes and contacts with the liquid supercooled carbon dioxide, causing the low-temperature, high-pressure gaseous carbon dioxide to condense into low-temperature, high-pressure liquid carbon dioxide, which is stored in the liquid storage container 33.

[0099] Energy release stage:

[0100] The liquid carbon dioxide in the liquid storage container 33 flows into the heat exchange structure 34 and evaporates into gaseous carbon dioxide after heat exchange with the heat supply medium flowing in the heat exchange structure 34 and passes through the gaseous carbon dioxide outlet;

[0101] Specifically, the third valve 32, the fifth valve 48, the ninth valve 45, the eleventh valve 47, and the thirteenth valve 55 are closed, and the twelfth valve 43, the eighth valve 44, the tenth valve 46, and the seventh valve 49 are opened; the first drive pump 51 is closed, and the liquid carbon dioxide in the liquid storage container 33 is transferred to the heat exchange structure 34 under the action of gravity, and a heating medium is injected into the heat exchange structure 34. The low-temperature and high-pressure liquid carbon dioxide entering the heat exchange structure 34 exchanges heat with the heating medium in the heat exchange structure 34, and the heat of the heating medium in the heat exchange structure 34 is transferred to the low-temperature and high-pressure liquid carbon dioxide, completing the evaporation process of the liquid carbon dioxide and turning into low-temperature and high-pressure gaseous carbon dioxide and flowing out.

[0102] The present disclosure provides a new method for condensing gaseous carbon dioxide. Compared with the existing technology, the present disclosure adopts a method of direct contact and mixing of liquid supercooled carbon dioxide and gaseous carbon dioxide, which can greatly improve the condensation efficiency and reduce power consumption.

[0103] Based on the control method of the storage device, the present disclosure provides a control method for a carbon dioxide energy storage system, including:

[0104] In the first working mode (energy storage stage):

[0105] The second valve 11, the first valve 10, the third valve 32, the fifth valve 48, the ninth valve 45, the eleventh valve 47, and the thirteenth valve 55 are opened, and the twelfth valve 43, the eighth valve 44, the tenth valve 46, the seventh valve 49, the fourth valve 14, and the sixth valve 15 are closed; the first driving pump 51 is started, and 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 and 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, and 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, so that the high-temperature and high-pressure gaseous carbon dioxide is converted into low-temperature and high-pressure gaseous carbon dioxide, and the low-temperature medium in the cold storage tank 23 is converted into a high-temperature medium and stored in the heat storage tank 24. Low-temperature, high-pressure gaseous carbon dioxide enters the liquid storage container 33. The first drive pump 51 transfers the liquid carbon dioxide in the liquid storage container 33 (which may be pre-stored there) into the heat exchange structure 34. A refrigerant is introduced into the heat exchange structure 34, where it exchanges heat with the liquid carbon dioxide entering the heat exchange structure 34, transforming the liquid carbon dioxide into supercooled liquid carbon dioxide. With the continued operation of the first drive pump 51, the supercooled carbon dioxide is transferred to the spraying device 50, overcoming gravity and resistance along the pipeline. The spray head sprays the supercooled carbon dioxide into the condensation area RP of the liquid storage container 33. The gaseous carbon dioxide entering the liquid storage container 33 directly mixes and contacts with the liquid supercooled carbon dioxide, condensing the low-temperature, high-pressure gaseous carbon dioxide into low-temperature, high-pressure liquid carbon dioxide, which is then stored in the liquid storage container 33. During power outages, the carbon dioxide energy storage system can operate in the first operating mode, utilizing surplus power to compress the gaseous carbon dioxide, condensing it into liquid carbon dioxide for storage, and simultaneously storing the heat energy generated during the compression process.

[0106] In the second working mode (energy release stage):

[0107] Close the second valve 11, the first valve 10, the third valve 32, the fifth valve 48, the ninth valve 45, and the eleventh valve 47, and open the twelfth valve 43, the eighth valve 44, the tenth valve 46, the seventh valve 49, the fourth valve 14, and the sixth valve 15; close the first driving pump 51, and the liquid carbon dioxide in the liquid storage container 33 is transferred to the heat exchange structure 34 under the action of gravity, and the heat supply medium is injected into the heat exchange structure 34. The low-temperature and high-pressure liquid carbon dioxide entering the heat exchange structure 34 exchanges heat with the heat supply medium in the heat exchange structure 34, and the heat of the heat supply medium in the heat exchange structure 34 is transferred to the low-temperature and high-pressure liquid carbon dioxide. The carbon dioxide completes the evaporation process of the liquid carbon dioxide, transforming into low-temperature, high-pressure gaseous carbon dioxide. It then enters the energy-release heat exchanger 42, exchanging heat with the high-temperature medium in the heat storage tank 24. The heat from the high-temperature medium is transferred to the low-temperature, high-pressure gaseous carbon dioxide, turning the high-temperature medium in the heat storage tank 24 into a low-temperature medium that is stored in the cold storage tank 23. The low-temperature, high-pressure gaseous carbon dioxide absorbs the heat, transforming into high-temperature, high-pressure gaseous carbon dioxide, which then enters the turbine 41 to expand and produce work. Generator G converts the mechanical energy generated by the turbine 41 into electrical energy. The low-temperature, low-pressure gaseous carbon dioxide, after expansion, is returned to the gas storage device 100 for storage, completing the energy-release phase. This mode is designed for operation during peak electricity demand periods, utilizing low-grade heat to vaporize the liquid carbon dioxide. The thermal energy stored in the first operating mode promotes the expansion of the gaseous carbon dioxide, driving turbine 41 to generate electricity. The expanded low-temperature, low-pressure gaseous carbon dioxide is then stored in the gas storage device 100 for the next cycle.

[0108] In the second working state, the thirteenth valve 55 can also be opened to balance the pressure of the storage device, so that the energy release stage can be completed with lower power consumption.

[0109] In the present disclosure, different connecting pipes and valves are set for the energy storage stage and the energy release stage, and the energy storage stage and the energy release stage can be quickly converted only by switching between the valves, thereby improving efficiency.

[0110] In the present disclosure, a storage device 300 with integrated condensation and evaporation is provided, and a spraying device 50 is used to spray liquid supercooled carbon dioxide to directly contact and mix it with the gaseous carbon dioxide entering the liquid storage container 33, so that the gaseous carbon dioxide is condensed and phase-changed into liquid carbon dioxide (or liquid supercooled carbon dioxide), and the cycle of carbon dioxide phase change is realized (the liquid carbon dioxide formed by the condensation of gaseous carbon dioxide can be supercooled to form liquid supercooled carbon dioxide and then continue to be used for the condensation of gaseous carbon dioxide). The heating medium circulating in the heat exchange structure 34 is used to make the liquid carbon dioxide (liquid supercooled carbon dioxide) phase-changed into gaseous carbon dioxide, realizing the integration of functions such as condensation and evaporation, which can reduce the number of equipment in the carbon dioxide energy storage system, reduce energy consumption, and reduce costs.

[0111] This disclosure provides a novel method for the condensation phase transition of gaseous carbon dioxide (using a condensation process in which liquid supercooled carbon dioxide directly contacts gaseous carbon dioxide to achieve condensation). This method boasts higher heat transfer efficiency and enables faster condensation. Compared to the partition-type condensation method used in related technologies, this highly efficient hybrid condensation method significantly improves the heat transfer coefficient, making the condensation process faster and more efficient.

[0112] Furthermore, in the present disclosure, the heat exchange structure 34 is arranged outside the liquid storage container 33, which is convenient for maintenance, can reduce costs, and is convenient for replacing the heat exchange structure 34 according to efficiency requirements, and the arrangement is flexible to meet needs.

[0113] In one embodiment of the present disclosure, see Figure 6 and Figure 7 The storage device also includes a storage unit 38 connected to the lower end of the liquid storage container 33. In other words, the lower end of the liquid storage container 33 has a third liquid carbon dioxide outlet. The storage unit 38 and the third liquid carbon dioxide outlet are connected via a transfer pipe 39, ensuring equalization of the liquid levels between the liquid storage container 33 and the storage unit 38, thereby balancing the pressure and storing the liquid carbon dioxide. A fourteenth valve 40 is provided on the transfer pipe 39. In one example, the storage unit 38 may include a single storage tank. In another example, the storage unit 38 may include at least two storage tanks, for example, two, three, or five storage tanks, each of which is independently controlled. The storage pipes may be connected in parallel and connected to the third liquid carbon dioxide outlet via the transfer pipe 39. In this example, the storage unit 38 is positioned lower than the liquid storage container 33. (This placement eliminates the need for a second drive pump on the transfer pipe 39, allowing the transfer of liquid carbon dioxide from the liquid storage container 33 to the storage unit 38 to be achieved solely by gravity.)

[0114] In another example, a second drive pump (not shown) can be provided to transfer liquid carbon dioxide between the storage unit 38 and the liquid storage container 33. In other words, the second drive pump is configured to transfer at least a portion of the liquid carbon dioxide in the storage unit 38 to the liquid storage container 33. Alternatively, the second drive pump can be configured to transfer at least a portion of the liquid carbon dioxide in the liquid storage container 33 to the storage unit 38. This allows for pre-replenishment of liquid carbon dioxide to the liquid storage container 33 (eliminating the need to retain liquid carbon dioxide in the liquid storage container 33, thereby increasing storage space for subsequent liquid carbon dioxide additions). In this example, the storage unit 38 can be positioned higher than the liquid storage container 33. During the energy storage phase, surplus power can be used to drive the second drive pump to transfer liquid carbon dioxide from the liquid storage container 33 to the storage unit 38. During the energy release phase, gravity can be used to transfer liquid carbon dioxide from the storage unit 38 to the storage unit 38, reducing power consumption and achieving energy release and storage.

[0115] In the present disclosure, the provision of storage unit 38 can increase storage capacity (increase the storage space for liquid carbon dioxide) and balance system pressure. In one embodiment, when a large amount of liquid carbon dioxide is formed during the energy storage phase, the fourteenth valve 40 can be opened to transfer the liquid carbon dioxide in the liquid storage container 33 to the storage unit 38 for storage. During the energy release phase, the fourteenth valve 40 is opened, and the second drive pump is used to pump the liquid carbon dioxide in the storage unit 38 into the liquid storage container 33. Simultaneously, the storage unit 38 can balance the pressure in the liquid storage container 33, thereby ensuring condensation efficiency. In another embodiment, the fourteenth valve 40 can be opened throughout the energy storage and release phases to balance system pressure.

[0116] In one embodiment of the present disclosure, the upper end of the storage unit 38 is connected to the second connecting pipe 31 and the third connecting pipe 37 via a balancing pipe 54. This further balances the system pressure (from the perspective of the gas (gaseous carbon dioxide)). In this example, during the energy storage and release phases, the thirteenth valve 55 can be opened to achieve the purpose of balancing the gas pressure using the balancing pipe 54.

[0117] Those skilled in the art will readily appreciate 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 common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, with the true scope and spirit of the present disclosure being indicated by the appended claims.

Claims

1. A storage device for a carbon dioxide energy storage system, characterized in that: include: A liquid storage container, wherein the internal cavity thereof comprises a condensation zone located at an upper portion and a storage zone located at a lower portion; the liquid storage container has a gaseous carbon dioxide inlet at the condensation zone and a first liquid carbon dioxide outlet at the storage zone; a heat exchange unit located outside the liquid storage container; the heat exchange unit comprises a heat exchange structure, a first connecting pipe, and a second connecting pipe; the heat exchange structure has a first liquid carbon dioxide inlet, a second liquid carbon dioxide outlet, and a gaseous carbon dioxide outlet, the first liquid carbon dioxide inlet being connected to the first liquid carbon dioxide outlet via the first connecting pipe; a spraying device, disposed in the condensation area of ​​the liquid storage container; the second liquid carbon dioxide outlet is connected to the spraying device through the second connecting pipe; The heat exchange unit is configured to allow the liquid carbon dioxide in the liquid storage container to flow into the heat exchange structure during the energy storage phase, and to form liquid supercooled carbon dioxide after heat exchange with the refrigerant flowing in the heat exchange structure, and to be pumped into the spraying device; and configured to allow the liquid carbon dioxide in the liquid storage container to flow into the heat exchange structure during the energy release phase, and evaporate into gaseous carbon dioxide after exchanging heat with the heat supply medium flowing in the heat exchange structure, and then pass through the gaseous carbon dioxide outlet; The heat exchange structure has a heat exchange medium inlet and a heat exchange medium outlet, wherein the heat exchange medium inlet has a first sub-inlet and a second sub-inlet; the heat exchange medium outlet has a first sub-outlet and a second sub-outlet; an eighth valve is provided at the first sub-inlet, and a tenth valve is provided at the first sub-outlet; a ninth valve is provided at the second sub-inlet, and an eleventh valve is provided at the second sub-outlet; in the energy release stage, the heating medium flows in from the first sub-inlet and flows out from the first sub-outlet; in the energy storage stage, the refrigerant medium flows in from the second sub-inlet and flows out from the second sub-outlet; The position of the heat exchange structure is lower than that of the liquid storage container; the first connecting pipe has a first sub-pipe and a second sub-pipe; the heat exchange unit further includes a first driving pump; Both ends of the first sub-pipeline and both ends of the second sub-pipeline are connected to the first liquid carbon dioxide outlet and the first liquid carbon dioxide inlet respectively; The first driving pump is arranged on the first sub-pipeline; The position of the heat exchange medium inlet is higher than the position of the heat exchange medium outlet.

2. The storage device of the carbon dioxide energy storage system according to claim 1, characterized in that: The storage device further comprises a storage unit; the storage unit is used to store liquid carbon dioxide; the storage unit is connected to the storage area of ​​the liquid storage container.

3. The storage device of the carbon dioxide energy storage system according to claim 2, characterized in that: The storage unit is connected to the storage area of ​​the liquid storage container via a transfer pipe; The transfer pipe is provided with a second driving pump, and the second driving pump is at least configured to transfer at least part of the liquid carbon dioxide in the storage unit to the liquid storage container.

4. The storage device of the carbon dioxide energy storage system according to claim 2, characterized in that: The upper end of the storage unit is communicated with the second communicating pipe and the gaseous carbon dioxide inlet.

5. A carbon dioxide energy storage system, characterized in that: A storage device having the carbon dioxide energy storage system according to any one of claims 1 to 4.

6. A method for controlling a storage device of a carbon dioxide energy storage system according to any one of claims 1 to 4, characterized in that: include: Energy storage stage: The liquid carbon dioxide in the liquid storage container flows into the heat exchange structure and forms liquid supercooled carbon dioxide after heat exchange with the refrigerant flowing in the heat exchange structure. The liquid supercooled carbon dioxide is then pumped into the spraying device. The spraying device sprays the liquid supercooled carbon dioxide in the condensation area. The liquid supercooled carbon dioxide directly mixes and contacts with the gaseous carbon dioxide entering the liquid storage container, thereby completing the condensation of the gaseous carbon dioxide. Energy release stage: The liquid carbon dioxide in the liquid storage container flows into the heat exchange structure, and evaporates into gaseous carbon dioxide after heat exchange with the heat supply medium flowing in the heat exchange structure, and passes through the gaseous carbon dioxide outlet.

Images