An energy storage system and method for storing supercritical carbon dioxide

Abstract

This invention belongs to the field of heat exchange and energy storage technology, and discloses an energy storage system and method for storing supercritical carbon dioxide. The system includes a first heat exchange pipeline, comprising a supercritical carbon dioxide station, a gas chamber, and an energy storage heat exchange section, with the gas chamber as the starting point and the supercritical carbon dioxide station as the ending point. Both the gas chamber and the supercritical carbon dioxide station are connected to the energy storage heat exchange section. By setting up a first and a second heat exchange pipeline, heat exchange between the first and second heat exchange pipelines can be achieved through the first heat exchanger during the energy storage stage. After the compressor operates, energy can be stored in the hot water of the second heat exchange pipeline. During the energy release stage, the invention employs a second, third, and fourth heat exchanger, allowing carbon dioxide to continuously absorb heat from the hot water and external heat sources, ultimately performing work through the turbine. Furthermore, after performing work, the waste heat from the hot water can be further absorbed through the third heat exchanger, thus improving the system's heat utilization efficiency.

Description

Technical Field

[0001] This invention belongs to the field of heat exchange and energy storage technology, and specifically relates to an energy storage system and method for storing supercritical carbon dioxide. Background Technology

[0002] The development of the new energy power generation industry can increase the proportion of new energy consumption and supply, thereby optimizing the energy structure and reducing dependence on traditional fossil fuels. However, new energy power generation is characterized by intermittency, fluctuation, and anti-peak shaving, making it severely dependent on weather and sunshine conditions, resulting in unstable output, difficulties in grid dispatch, and frequent instances of wind and solar curtailment. The increasing proportion of intermittent energy generation capacity such as wind and solar power leads to a greater difference between peak and valley loads in the system. Therefore, thermal power units need to frequently enter a deep peak-shaving operating state. Existing measures to improve the flexibility of coal-fired power plants include bypass modifications, electrothermal conversion, and waste energy utilization. Frequent and large-scale adjustments reduce the lifespan of the units and lead to lower efficiency. In contrast, compressed gas energy storage technology can reduce the impact of uncertainties on the load side by reducing the impact of uncertainties on the source side, while achieving matching between the source and load sides without sacrificing system efficiency or reducing energy quality, and has the potential for efficient cross-temporal and spatial regulation.

[0003] Because supercritical carbon dioxide possesses both the low viscosity and high diffusion coefficient of gases and the high density of liquids, it has gradually attracted widespread attention in the petroleum industry in recent years. Extensive research has been conducted abroad on the application of supercritical carbon dioxide in the development of unconventional oil and gas reservoirs, and various technologies have been applied to field operations such as drilling, fracturing, and miscible flooding, achieving excellent results. Summary of the Invention

[0004] To address at least one of the problems in the background art, the present invention proposes an energy storage system and method for storing supercritical carbon dioxide.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] An energy storage system for storing supercritical carbon dioxide, comprising:

[0007] The first heat exchange pipeline is equipped with a supercritical carbon dioxide station, a gas chamber, and an energy storage heat exchange section, with the gas chamber as the starting point and the supercritical carbon dioxide station as the ending point. Both the gas chamber and the supercritical carbon dioxide station are connected to the energy storage heat exchange section.

[0008] The second heat exchange pipeline is equipped with a normal temperature water tank and a hot water tank, with the normal temperature water tank as the starting point and the hot water tank as the ending point. Both the normal temperature water tank and the hot water tank are connected to the energy storage heat exchange section.

[0009] The energy storage heat exchange section is used for heat exchange between the first heat exchange pipeline and the second heat exchange pipeline;

[0010] The third heat exchange pipeline starts from the hot water tank and ends at the room temperature water tank. It is used to release the heat energy of the hot water in the hot water tank and store the room temperature water in the room temperature water tank after cooling.

[0011] The fourth heat exchange pipeline starts from the supercritical carbon dioxide station and ends at the gas chamber. Between the supercritical carbon dioxide station and the gas chamber, there are gas-water heating section, heat replenishment section and preheating section.

[0012] The gas-water heating section is used to exchange heat with the third heat exchange pipeline to raise the temperature of carbon dioxide;

[0013] The reheating section is connected to the gas-water heating section and is used to reheat the carbon dioxide after it has been heated.

[0014] The preheating section is used to preheat the carbon dioxide entering the gas-water heating section;

[0015] The fifth heat exchange pipeline is used to introduce hot water into the supplementary heating section for heat exchange.

[0016] Preferably, the energy storage heat exchange section includes n compressors and n first heat exchangers, where n≥3;

[0017] The inlet of the i-th compressor is connected to the hot end outlet of the (i-1)-th first heat exchanger;

[0018] The outlet of the i-th compressor is connected to the hot end inlet of the (i+1)-th first heat exchanger, where n > i > 1;

[0019] The inlet of the first compressor is connected to the outlet of the gas chamber via a pipeline;

[0020] The hot end outlet of the nth heat exchanger is connected to the inlet of the supercritical carbon dioxide station via a pipeline.

[0021] Preferably, a first valve is installed on the pipeline connecting the first compressor to the gas chamber, and a second valve is installed on the pipeline connecting the nth first heat exchanger to the supercritical carbon dioxide station.

[0022] Preferably, in the second heat exchange pipeline, each of the n cold end inlets of the first heat exchangers is connected to a first circulation pump, and each of the n cold end outlets of the first heat exchangers is connected to the inlet of the hot water tank.

[0023] The end of the first circulating pump furthest from the first heat exchanger is connected to the outlet of the ambient temperature water tank.

[0024] Preferably, z second heat exchangers are provided in the third heat exchange pipeline, where z ≥ 4;

[0025] The hot end inlets of the first to z-1 second heat exchangers are all connected to the outlet of the second circulation pump, and the inlet of the second circulation pump is connected to the outlet of the hot water tank.

[0026] The hot end outlets of the first to m second heat exchangers are connected to the hot end inlet of the z-th second heat exchanger, where m ≥ 2;

[0027] The hot end outlet of the z-th second heat exchanger is connected to a cooling tower;

[0028] The hot end outlet of the m+1 to z-1th second heat exchangers is connected to the cooling tower;

[0029] The cooling tower is also connected to a normal temperature water tank;

[0030] The cold end inlet and cold end outlet of the first to z-1 second heat exchangers are used to be installed in the fourth heat exchange pipeline for heat exchange.

[0031] Preferably, in the fourth heat exchange pipeline, a third heat exchanger is provided in the preheating section;

[0032] The cold end inlet of the third heat exchanger is connected to the third valve, and the third valve is connected to the outlet of the supercritical carbon dioxide station; the cold end outlet of the third heat exchanger is connected to the inlet of the gas-water heating section.

[0033] The hot end outlet of the third heat exchanger is connected to a fourth valve, which is connected to the inlet of the gas chamber; the hot end inlet of the third heat exchanger is connected to the outlet of the reheating section.

[0034] Preferably, in the fourth heat exchange pipeline, the gas-water heating section includes z second heat exchangers, and the supplementary heating section includes k fourth heat exchangers and k turbines, where k≥3, z≥4, and z=k+1;

[0035] Wherein, the cold end inlet of the j-th second heat exchanger is connected to the outlet of the (j+1)-th turbine, the cold end outlet of the j-th second heat exchanger is connected to the cold end inlet of the j-th fourth heat exchanger, and the cold end outlet of the j-th fourth heat exchanger is connected to the inlet of the j-th turbine, z-1≥j≥1;

[0036] The outlet of the first turbine is connected to the hot end inlet of the third heat exchanger;

[0037] The cold end inlet of the z-th second heat exchanger is connected to the cold end outlet of the third heat exchanger, and the cold end outlet of the z-th second heat exchanger is connected to the cold end inlet of the k-th fourth heat exchanger.

[0038] Preferably, the k turbines are connected in sequence, wherein the first turbine is connected to a generator.

[0039] Preferably, the fifth heat exchange pipeline is provided with an inlet water pipeline and a return water pipeline;

[0040] Among them, the hot end inlets of k of the fourth heat exchangers are all connected to the water inlet pipe;

[0041] The hot end outlets of each of the k fourth heat exchangers are connected to the return water pipeline;

[0042] The inlet pipe is used to supply hot water.

[0043] Preferably, each of the compressors is connected to an electric motor.

[0044] A method for storing supercritical carbon dioxide, used in the aforementioned supercritical carbon dioxide storage system, includes the following energy storage steps:

[0045] The first and second heat exchange pipelines are opened, and the carbon dioxide in the gas chamber is introduced into the energy storage heat exchange section to heat up and release heat, and the temperature drops. Then the cooled carbon dioxide is stored in the supercritical carbon dioxide station.

[0046] Meanwhile, room temperature water in the ambient temperature tank enters the energy storage heat exchange section to absorb the heat released by carbon dioxide and obtain hot water, which is then stored in the hot water tank.

[0047] Preferably, it further includes an energy release step:

[0048] Open the third, fourth, and fifth heat exchange pipelines;

[0049] In the third pipeline, the hot water tank passes hot water into the gas-water heating section to release heat, and finally the hot water is cooled and stored in the room temperature water tank.

[0050] Meanwhile, in the fourth pipeline, the carbon dioxide in the supercritical carbon dioxide station enters the preheating section for preheating, then enters the gas-water heating section for heating, then enters the reheating section for heating again, and then enters the turbine to do turbine work, which reduces the temperature of the carbon dioxide. The cooled carbon dioxide then enters the preheating section to release heat again, and finally is stored in the gas chamber.

[0051] Meanwhile, in the fifth pipeline, hot water enters the heat replenishment section and releases heat.

[0052] The beneficial effects of this invention are:

[0053] 1. By setting up a first heat exchange pipeline and a second heat exchange pipeline, the present invention can realize heat exchange between the first heat exchange pipeline and the second heat exchange pipeline through the first heat exchanger during the energy storage stage. After the compressor starts working, the energy can be stored in the hot water of the second heat exchange pipeline to prepare for the energy release stage.

[0054] 2. This invention uses a second, third, and fourth heat exchanger during the energy release stage, which allows carbon dioxide to continuously absorb heat from hot water and external heat sources, and finally perform work through a turbine. After performing work, the waste heat from the hot water can be further absorbed through the third heat exchanger, thereby improving the heat utilization efficiency of the system.

[0055] 3. This invention utilizes existing supercritical carbon dioxide pipelines in oil and gas extraction facilities to store high-pressure working fluid, eliminating the need for separate high-pressure storage tanks and reducing construction costs; this invention uses external heat sources such as waste heat from power plants to heat the main gas, improving the main gas's work capacity and thus enhancing system efficiency.

[0056] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description and the drawings. Attached Figure Description

[0057] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0058] Figure 1 A schematic diagram of the structure of an energy storage system for storing supercritical carbon dioxide according to the present invention is shown;

[0059] Figure 2 The structural diagram of the first and second heat exchange pipelines of the energy storage system is shown.

[0060] Figure 3 The diagram shows the structure of the third heat exchange pipeline in the energy storage system;

[0061] Figure 4 The structural diagrams of the fourth and fifth heat exchange pipelines of the energy storage system are shown.

[0062] In the diagram: 1. Compressor; 2. First heat exchanger; 3. Supercritical carbon dioxide station; 4. First valve; 5. Gas chamber; 6. Second valve; 7. Ambient temperature water tank; 8. First circulating pump; 9. Hot water tank; 10. Second circulating pump; 11. Second heat exchanger; 12. Cooling tower; 13. Third valve; 14. Third heat exchanger; 15. Fourth heat exchanger; 16. Turbine; 17. Generator; 18. External heat source; 19. Fourth valve; 20. Electric motor. Detailed Implementation

[0063] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0064] An energy storage system for storing supercritical carbon dioxide, such as Figure 1 As shown, it includes an energy storage system and an energy release system. The energy storage system consists of a first heat exchange pipeline and a second heat exchange pipeline, and the energy release system consists of a third heat exchange pipeline, a fourth heat exchange pipeline, and a fifth heat exchange pipeline.

[0065] like Figure 2 As shown, the first heat exchange pipeline includes a supercritical carbon dioxide station 3, a gas chamber 5, and an energy storage heat exchange section, with gas chamber 5 as the starting point and supercritical carbon dioxide station 3 as the ending point. Both gas chamber 5 and supercritical carbon dioxide station 3 are connected to the energy storage heat exchange section. The energy storage heat exchange section includes n compressors 1 and n first heat exchangers 2, where n ≥ 3. Figure 2 Taking n=3 as an example, the inlet of the i-th compressor 1 is connected to the hot end outlet of the (i-1)-th first heat exchanger 2; the outlet of the i-th compressor 1 is connected to the hot end inlet of the (i+1)-th first heat exchanger 2, where n>i>1; the inlet of the first compressor 1 is connected to the outlet of the gas chamber 5 via a pipeline; and the hot end outlet of the n-th first heat exchanger 2 is connected to the inlet of the supercritical carbon dioxide station 3 via a pipeline. Furthermore, a first valve 4 is installed on the pipeline connecting the first compressor 1 to the gas chamber 5, and a second valve 6 is installed on the pipeline connecting the n-th first heat exchanger 2 to the supercritical carbon dioxide station 3.

[0066] It should be noted that, in Figure 2 In this system, each compressor 1 is connected to an electric motor 20, which supplies power to the compressor 1.

[0067] like Figure 2 As shown, the second heat exchange pipeline includes a room temperature water tank 7 and a hot water tank 9, with room temperature water tank 7 as the starting point and hot water tank 9 as the ending point. Both the room temperature water tank 7 and hot water tank 9 are connected to the energy storage heat exchange section. The energy storage heat exchange section is used for heat exchange between the first and second heat exchange pipelines. Specifically, in the second heat exchange pipeline, the cold end inlets of each of the n first heat exchangers 2 are connected to a first circulation pump 8, and the cold end outlets of each of the n first heat exchangers 2 are connected to the inlet of the hot water tank 9. Furthermore, the end of the first circulation pump 8 furthest from the first heat exchanger 2 is connected to the outlet of the room temperature water tank 7.

[0068] It should be noted that, with Figure 2Taking n=3 as an example, the three compressors 1 in the first heat exchange pipeline sequentially perform work on the carbon dioxide flowing out of the gas chamber 5. Each time the carbon dioxide is heated, it releases heat energy in the first heat exchanger 2, eventually forming supercritical carbon dioxide and storing it in the supercritical carbon dioxide station 3. At the same time, the heat energy released by the carbon dioxide is absorbed by room temperature water in the first heat exchanger 2, and then the room temperature water is heated to become hot water and stored in the hot water tank 9.

[0069] like Figure 3 As shown, the third heat exchange pipeline starts at hot water tank 9 and ends at room temperature water tank 7. It is used to release the heat energy of the hot water in hot water tank 9 and store the cooled water in room temperature water tank 7. Specifically, the third heat exchange pipeline is equipped with z second heat exchangers 11, where z ≥ 4. Figure 3 Taking z=4 as an example, the hot end inlets of the first to third second heat exchangers 11 are all connected to the outlet of the second circulation pump 10, and the inlet of the second circulation pump 10 is connected to the outlet of the hot water tank 9; the hot end outlets of the first to m second heat exchangers 11 are connected to the hot end inlet of the z-th second heat exchanger 11, where m≥2. Figure 3 In the middle, m=2; in addition, the hot end outlet of the fourth second heat exchanger 11 is connected to the cooling tower 12; the hot end outlet of the third second heat exchanger 11 is connected to the cooling tower 12; and the cooling tower 12 is also connected to the ambient temperature water tank 7; in addition, the cold end inlet and cold end outlet of the first to third second heat exchangers 11 are used to install in the fourth heat exchange pipeline for heat exchange.

[0070] like Figure 4 As shown, the fourth heat exchange pipeline starts at the supercritical carbon dioxide station 3 and ends at the gas chamber 5. Between the supercritical carbon dioxide station 3 and the gas chamber 5, there are a gas-water heating section, a reheating section, and a preheating section. The gas-water heating section is used to exchange heat with the third heat exchange pipeline to raise the temperature of the carbon dioxide. The reheating section is connected to the gas-water heating section and is used to reheat the carbon dioxide after it has been heated. Specifically, the gas-water heating section includes z second heat exchangers 11, and the supplementary heating section includes k fourth heat exchangers 15 and k turbines 16, where k≥3, z≥4, and z=k+1; wherein, the cold end inlet of the j-th second heat exchanger 11 is connected to the outlet of the (j+1)-th turbine 16, the cold end outlet of the j-th second heat exchanger 11 is connected to the cold end inlet of the j-th fourth heat exchanger 15, the cold end outlet of the j-th fourth heat exchanger 15 is connected to the inlet of the j-th turbine 16, and z-1≥j≥1; the outlet of the first turbine 16 is connected to the hot end inlet of the third heat exchanger 14; the cold end inlet of the z-th second heat exchanger 11 is connected to the cold end outlet of the third heat exchanger 14, and the cold end outlet of the z-th second heat exchanger 11 is connected to the cold end inlet of the k-th fourth heat exchanger 15.

[0071] It should be noted that, in Figure 4 In the given information, z = 4 and k = 3.

[0072] like Figure 4 As shown, the preheating section is used to preheat the carbon dioxide entering the gas-water heating section. Specifically, in the fourth heat exchange pipeline, the preheating section is equipped with a third heat exchanger 14; the cold end inlet of the third heat exchanger 14 is connected to a third valve 13, which is connected to the outlet of the supercritical carbon dioxide station 3; the cold end outlet of the third heat exchanger 14 is connected to the inlet of the gas-water heating section; the hot end outlet of the third heat exchanger 14 is connected to a fourth valve 19, which is connected to the inlet of the gas chamber 5; and the hot end inlet of the third heat exchanger 14 is connected to the outlet of the reheating section. Additionally, k turbines 16 are connected sequentially, with the first turbine 16 connected to a generator 17.

[0073] like Figure 4 As shown, the fifth heat exchange pipeline is used to introduce hot water into the heat exchange section for heat exchange, and is specifically equipped with an inlet pipeline and a return pipeline; wherein, the hot end inlets of k fourth heat exchangers 15 are all connected to the inlet pipeline; the hot end outlets of k fourth heat exchangers 15 are all connected to the return pipeline; in addition, both the inlet pipeline and the return pipeline are connected to an external heat source 18 (generally waste heat from a power plant). The external heat source 18 can introduce hot water into the inlet pipeline, where the hot water undergoes heat exchange in the fourth heat exchangers 15, and then returns to the external heat source 18 through the return pipeline.

[0074] by Figures 1-4 Taking the energy storage system mentioned above as an example, this paper introduces an energy storage method for storing supercritical carbon dioxide, which includes an energy storage step and an energy release step.

[0075] The energy storage process involves the following steps: First heat exchange pipelines 4 and 6 are opened, while third valve 13 and fourth valve 19 are closed. Motor 20 is started, driving compressor 1 and starting the first circulation pump 8. Then, ambient temperature and pressure carbon dioxide from gas chamber 5 is sequentially introduced into the three compressors 1, compressing it to high pressure. The carbon dioxide is then heated between two compressors 1 via the first heat exchanger 2, releasing heat to obtain supercritical carbon dioxide. This supercritical carbon dioxide gas is then stored in the supercritical carbon dioxide station 3 via a supercritical carbon dioxide pipeline. Simultaneously, ambient temperature water from ambient temperature water tank 7 enters the first heat exchanger 2 to absorb the heat released by the carbon dioxide, obtaining hot water, which is then stored in hot water tank 9.

[0076] Energy release steps: Open the third valve 13 and the fourth valve 19 to open the third, fourth, and fifth heat exchange pipelines, while simultaneously closing the first valve 4 and the second valve 6. In the third pipeline, hot water tank 9 releases heat after passing hot water into the gas-water heating section. The hot water is then cooled in the cooling tower 12 and stored in the ambient temperature water tank 7. Simultaneously, in the fourth pipeline, carbon dioxide from the supercritical carbon dioxide station 3 enters the preheating section for preheating, then enters the gas-water heating section for heating, and then enters the reheating section for further heating. Afterward, the carbon dioxide enters the turbine 16 to perform turbine work, causing the carbon dioxide temperature to decrease. The cooled carbon dioxide then enters the preheating section again to release heat and is finally stored in the gas chamber 5. Simultaneously, in the fifth pipeline, hot water enters the reheating section and releases heat.

[0077] It should be noted that in the energy release step, the supercritical carbon dioxide from the supercritical carbon dioxide station 3 absorbs the waste heat of the exhaust gas through the third heat exchanger 14; the supercritical carbon dioxide from the third heat exchanger 14 absorbs the heat of the hot water through the second heat exchanger 11; the supercritical carbon dioxide from the second heat exchanger 11 absorbs the heat provided by the external heat source 18 through the fourth heat exchanger 15; the supercritical carbon dioxide from the fourth heat exchanger 15 enters the turbine 16 to do work; the carbon dioxide from the turbine 16 absorbs heat through the second heat exchanger 11 and the fourth heat exchanger 15 in sequence; then the supercritical carbon dioxide from the fourth heat exchanger 15 enters the turbine 16 to do work; then the carbon dioxide from the turbine 16 absorbs heat through the second heat exchanger 11 and the fourth heat exchanger 15 in sequence; then the supercritical carbon dioxide from the fourth heat exchanger 15 enters the turbine 16 to do work; then the carbon dioxide exhaust gas from the turbine 16 enters the third heat exchanger 14 to release heat and is cooled at the same time; the carbon dioxide gas from the third heat exchanger 14 enters the gas chamber 5 for storage. Meanwhile, the hot water from the second heat exchanger 11 enters the cooling tower 12 and is cooled to room temperature; the room temperature water from the cooling tower 12 enters the room temperature water tank 7 for storage.

[0078] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An energy storage system for storing supercritical carbon dioxide, characterized in that, include: The first heat exchange pipeline is equipped with a supercritical carbon dioxide station (3), a gas chamber (5) and an energy storage heat exchange section, with the gas chamber (5) as the starting point and the supercritical carbon dioxide station (3) as the ending point. Both the gas chamber (5) and the supercritical carbon dioxide station (3) are connected to the energy storage heat exchange section. The second heat exchange pipeline is equipped with a normal temperature water tank (7) and a hot water tank (9), with the normal temperature water tank (7) as the starting point and the hot water tank (9) as the ending point. Both the normal temperature water tank (7) and the hot water tank (9) are connected to the energy storage heat exchange section. The energy storage heat exchange section is used for heat exchange between the first heat exchange pipeline and the second heat exchange pipeline; The third heat exchange pipeline starts from the hot water tank (9) and ends at the room temperature water tank (7). It is used to release the heat energy of the hot water in the hot water tank (9) and store the room temperature water in the room temperature water tank (7) after cooling. The fourth heat exchange pipeline starts from the supercritical carbon dioxide station (3) and ends at the gas chamber (5). Between the supercritical carbon dioxide station (3) and the gas chamber (5), there are gas-water heating section, heat replenishment section and preheating section. The gas-water heating section is used to exchange heat with the third heat exchange pipeline to raise the temperature of carbon dioxide; The reheating section is connected to the gas-water heating section and is used to reheat the carbon dioxide after it has been heated. The preheating section is used to preheat the carbon dioxide entering the gas-water heating section; The fifth heat exchange pipeline is used to introduce hot water into the heat exchange section for heat exchange; The energy storage heat exchange section includes n compressors (1) and n first heat exchangers (2), where n≥3; The inlet of the i-th compressor (1) is connected to the hot end outlet of the (i-1)-th first heat exchanger (2); The outlet of the i-th compressor (1) is connected to the hot end inlet of the (i+1)-th first heat exchanger (2), where n > i > 1; The inlet of the first compressor (1) is connected to the outlet of the gas chamber (5) via a pipeline; The hot end outlet of the nth first heat exchanger (2) is connected to the inlet of the supercritical carbon dioxide station (3) via a pipeline; In the second heat exchange pipeline, the cold end inlets of n first heat exchangers (2) are all connected to a first circulation pump (8), and the cold end outlets of n first heat exchangers (2) are all connected to the inlet of a hot water tank (9); The end of the first circulating pump (8) away from the first heat exchanger (2) is connected to the outlet of the ambient temperature water tank (7).

2. The energy storage system for storing supercritical carbon dioxide according to claim 1, characterized in that, A first valve (4) is installed on the pipeline connecting the first compressor (1) and the gas chamber (5), and a second valve (6) is installed on the pipeline connecting the nth first heat exchanger (2) and the supercritical carbon dioxide station (3).

3. The energy storage system for storing supercritical carbon dioxide according to claim 1, characterized in that, In the third heat exchange pipeline, there are z second heat exchangers (11), z≥4; The hot end inlets of the first to z-1 second heat exchangers (11) are all connected to the outlet of the second circulation pump (10), and the inlet of the second circulation pump (10) is connected to the outlet of the hot water tank (9); The hot end outlets of the first to m second heat exchangers (11) are connected to the hot end inlet of the z-th second heat exchanger (11), where m ≥ 2; The hot end outlet of the z-th second heat exchanger (11) is connected to a cooling tower (12). The hot end outlet of the m+1 to z-1th second heat exchanger (11) is connected to the cooling tower (12); The cooling tower (12) is also connected to a normal temperature water tank (7); The cold end inlet and cold end outlet of the first to z-1 second heat exchangers (11) are used to be installed in the fourth heat exchange pipeline for heat exchange.

4. The energy storage system for storing supercritical carbon dioxide according to claim 3, characterized in that, In the fourth heat exchange pipeline, a third heat exchanger (14) is provided in the preheating section. The cold end inlet of the third heat exchanger (14) is connected to the third valve (13), and the third valve (13) is connected to the outlet of the supercritical carbon dioxide station (3); the cold end outlet of the third heat exchanger (14) is connected to the inlet of the gas-water heating section. The hot end outlet of the third heat exchanger (14) is connected to a fourth valve (19), which is connected to the inlet of the gas chamber (5); the hot end inlet of the third heat exchanger (14) is connected to the outlet of the supplementary heating section.

5. The energy storage system for storing supercritical carbon dioxide according to claim 4, characterized in that, In the fourth heat exchange pipeline, the gas-water heating section includes z second heat exchangers (11), and the supplementary heating section includes k fourth heat exchangers (15) and k turbines (16), where k≥3, z≥4, and z=k+1; Wherein, the cold end inlet of the j-th second heat exchanger (11) is connected to the outlet of the (j+1)-th turbine (16), the cold end outlet of the j-th second heat exchanger (11) is connected to the cold end inlet of the j-th fourth heat exchanger (15), the cold end outlet of the j-th fourth heat exchanger (15) is connected to the inlet of the j-th turbine (16), and z-1≥j≥1; The outlet of the first turbine (16) is connected to the hot end inlet of the third heat exchanger (14); The cold end inlet of the z-th second heat exchanger (11) is connected to the cold end outlet of the third heat exchanger (14), and the cold end outlet of the z-th second heat exchanger (11) is connected to the cold end inlet of the k-th fourth heat exchanger (15).

6. The energy storage system for storing supercritical carbon dioxide according to claim 5, characterized in that, k turbines (16) are connected in sequence, wherein the first turbine (16) is connected to a generator (17).

7. The energy storage system for storing supercritical carbon dioxide according to claim 6, characterized in that, The fifth heat exchange pipeline is equipped with an inlet water pipeline and a return water pipeline; Among them, the hot end inlets of k of the fourth heat exchangers (15) are all connected to the water inlet pipe; The hot end outlets of all k fourth heat exchangers (15) are connected to the return water pipeline; The inlet pipe is used to supply hot water.

8. An energy storage system for storing supercritical carbon dioxide according to any one of claims 1-7, characterized in that, Each of the compressors (1) is connected to an electric motor (20).

9. A method for storing supercritical carbon dioxide, characterized in that, An energy storage system for storing supercritical carbon dioxide as described in any one of claims 1-8, comprising the energy storage step: Open the first heat exchange pipeline and the second heat exchange pipeline, and pass the carbon dioxide in the gas chamber (5) into the energy storage heat exchange section to heat up and release heat. The temperature drops, and then the cooled carbon dioxide is stored in the supercritical carbon dioxide station (3). Meanwhile, the room temperature water in the room temperature water tank (7) enters the energy storage heat exchange section to absorb the heat released by carbon dioxide and obtain hot water, and then the hot water is stored in the hot water tank (9).

10. The energy storage method for storing supercritical carbon dioxide according to claim 9, characterized in that, It also includes the energy release step: Open the third, fourth, and fifth heat exchange pipelines; In the third pipeline, the hot water tank (9) releases heat after passing hot water into the gas-water heating section, and finally the hot water is cooled and stored in the room temperature water tank (7); Meanwhile, in the fourth pipeline, the carbon dioxide in the supercritical carbon dioxide station (3) enters the preheating section for preheating, then enters the gas-water heating section for heating, and then enters the supplementary heating section for heating again. After that, the carbon dioxide enters the turbine (16) to perform turbine work, which reduces the temperature of the carbon dioxide. Then the carbon dioxide with reduced temperature enters the preheating section to release heat again, and finally is stored in the gas chamber (5). Meanwhile, in the fifth pipeline, hot water enters the heat replenishment section and releases heat.

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