Solid carbon dioxide energy storage and release integrated device and control method thereof

Abstract

The invention discloses a solid carbon dioxide energy storage and release integrated device and a control method thereof. One or more uniformly distributed injection expansion valves are arranged on the side wall of the closed high-pressure storage tank, and liquid carbon dioxide is expanded and converted into solid carbon dioxide in the energy storage stage and stored in the closed high-pressure storage tank; in the energy release stage, the solid carbon dioxide is converted into high-pressure gaseous carbon dioxide to drive a gaseous driving generator to generate power, and high-density storage and high-efficiency release of energy are completed; the carbon dioxide is re-liquefied through compression and cooling after energy release and returns to the liquid storage tank, closed-loop circulation is formed among the liquid state, the solid state and the gas state, and solid carbon dioxide storage is achieved; the whole circulation process is efficient in design, safe and environmentally friendly, carbon dioxide leakage or waste is reduced, and an innovative solution meeting the energy storage requirement in the future is embodied.

Description

Technical Field

[0001] The present invention relates to energy storage technology, and particularly to a solid carbon dioxide energy storage and energy release integrated device and its control method. Background Art

[0002] Currently, the new energy industry has an increasing demand for large-scale and long-term energy storage systems. Traditional energy storage methods such as battery energy storage, pumped hydro energy storage, and compressed air energy storage have problems such as low energy density, large space requirements, or high construction costs. In addition, the research on carbon dioxide energy storage mainly focuses on the compression and expansion of gaseous or liquid CO2, while the research on solid CO2 (dry ice) energy storage is less.

[0003] Existing solid carbon dioxide energy storage devices generally have a structural form in which the energy storage unit and the energy release unit are separately arranged. In the actual application process, after the solid carbon dioxide is stored, it needs to be transferred to an independent energy release device through an intermediate transmission link for sublimation and gasification, so as to release energy. Due to problems such as temperature gradient difference, environmental heat loss, gas leakage, and poor thermal coupling at the interfaces between devices in this process, a large amount of irreversible energy loss often occurs during the energy transfer and conversion process, seriously affecting the overall energy storage efficiency and energy release response speed of the system, and it is difficult to meet the requirements of efficient, safe, and integrated energy management. Summary of the Invention

[0004] In view of the above problems existing in the prior art, the present invention proposes a solid carbon dioxide energy storage and energy release integrated device and its control method. Solid carbon dioxide is formed by the rapid injection and expansion of liquid CO2 and stored in a high-pressure and low-temperature tank body to achieve high-energy-density storage; in the energy release stage, liquid CO2 is injected into the energy storage tank and mixed with solid carbon dioxide to generate high-pressure gaseous CO2 for driving a turbine to generate electricity, completing an efficient energy release cycle.

[0005] An object of the present invention is to propose a solid carbon dioxide energy storage and energy release integrated device.

[0006] The integrated solid carbon dioxide energy storage and release device of the present invention includes: a closed high-pressure storage tank, an energy storage stage inlet, an injection expansion valve, an energy storage stage inlet switching valve, an energy storage stage hydraulic pump, an energy storage stage outlet, a first switching valve, an energy release stage inlet, an energy release stage inlet switching valve, an energy release stage hydraulic pump, an energy storage stage outlet, a second switching valve, an energy storage stage pipeline, and an energy release stage pipeline; wherein, the closed high-pressure storage tank is a closed cylindrical shell with a space inside, placed upright, that is, the central axis of the cylinder is in the vertical direction; one or more evenly distributed energy storage stage inlets are circumferentially provided on the side wall of the closed high-pressure storage tank, an energy storage stage inlet switching valve is provided in front of each energy storage stage inlet, an injection expansion valve is provided in each energy storage stage inlet, and the injection head of the injection expansion valve is located on the inner wall of the closed high-pressure storage tank; an energy storage stage outlet is provided at the top of the closed high-pressure storage tank, and a first switching valve is provided at the energy storage stage outlet; an energy release stage inlet is provided on the side wall of the closed high-pressure storage tank, and an energy release stage inlet switching valve is provided in front of the energy release stage inlet; an energy release stage outlet is provided at the bottom, and a second switching valve is provided at the energy release stage outlet;

[0007] Each energy storage stage inlet pipeline is correspondingly connected to the corresponding energy storage stage inlet, the energy storage stage outlet is connected to the energy storage stage outlet pipeline, and an energy storage stage pipeline is connected between the energy storage stage inlet pipeline and the energy storage stage outlet pipeline; an energy storage stage hydraulic pump is respectively provided on each energy storage stage inlet pipeline; the energy storage and release stage inlet pipeline is connected to the energy release stage inlet, the energy release stage outlet is connected to the energy release stage outlet pipeline, and an energy release stage pipeline is connected between the energy release stage inlet pipeline and the energy release stage outlet pipeline; an energy release stage hydraulic pump is provided on the energy release stage inlet pipeline; a gaseous drive generator is provided on the energy release stage pipeline.

[0008] The closed high-pressure storage tank adopts a double-layer heat insulation layer. The inner layer is made of low-temperature resistant materials and high-strength materials, and the outer layer is a vacuum heat insulation layer. The materials have good low-temperature ductility and corrosion resistance, and are suitable for low-temperature (-78.5 °C) and medium-high pressure (0.5 MPa to 12 MPa) environments; Ni alloy steel stainless steel (such as 304, 316L), low-temperature alloy steel (9% Ni steel), aluminum alloy, or other materials suitable for environments below -80 °C, with a design pressure range of 0.1 to 12 MPa, and equipped with a multi-point temperature and pressure monitoring device.

[0009] The gaseous drive generator is a turbine.

[0010] It also includes a liquid storage tank, a container for storing liquid carbon dioxide, which operates under low temperature and high pressure conditions to ensure that the liquid carbon dioxide is in a stable state. The liquid carbon dioxide is stored in the liquid storage tank. At the ends of the energy storage stage pipeline and the energy release stage pipeline respectively, they are connected to two inlets of the liquid storage tank. One or more energy storage stage outlets of the liquid storage tank are respectively connected to the corresponding one or more energy storage stage inlet pipelines, and the energy release stage outlet of the liquid storage tank is connected to the energy release stage inlet pipeline. A compressor is provided on the energy storage stage outlet pipeline. The gaseous carbon dioxide generated after expansion in the closed high-pressure storage tank is introduced into the compressor for compression and then flows back to the liquid storage tank through the energy storage stage pipeline to achieve the recycling of the gas.

[0011] The injection head diameter of the injection expansion valve is 0.1 mm to 70 mm to adapt to different flow requirements, and the expansion efficiency reaches 40% to 60%.

[0012] The scales of the closed high-pressure storage tank and the gaseous drive generator are adjusted according to the application requirements to adapt to a volume range of 3 m 3 ~100 m 3 of the volume range.

[0013] It also includes a heating heat exchange device and a multi-stage cooling device. The heating heat exchange device is respectively provided on the energy storage stage pipeline and behind the compressor and on the energy release stage pipeline and before the gaseous drive generator to heat and raise the temperature of the carbon dioxide. Before the energy storage stage pipeline and the energy release stage pipeline enter the liquid storage tank, a multi-stage cooling device is provided to gradually cool down and liquefy the gaseous carbon dioxide and flow back to the liquid storage tank for storage.

[0014] Furthermore, the present invention also includes a temperature sensor and a force sensor, which are provided on the second switching valve and the first switching valve respectively to monitor the temperature and pressure of the closed high-pressure storage tank during the energy storage stage and the energy release stage.

[0015] The present invention further includes a gas-liquid separation device, which is provided on the inner wall of the closed high-pressure storage tank and at the energy storage stage outlet to leave the solid carbon dioxide in the solid storage tank, and the gaseous carbon dioxide is discharged from the energy storage stage outlet through the gas-liquid separation device. The gas-liquid separation device adopts a filter.

[0016] Another object of the present invention is to propose a control method for the integrated solid carbon dioxide energy storage and energy release device.

[0017] The control method for the integrated solid carbon dioxide energy storage and energy release device of the present invention includes the following steps:

[0018] a) Energy storage stage:

[0019] 1) The liquid carbon dioxide is pressurized by the energy storage stage hydraulic pump;

[0020] 2) Open the inlet switch valve in the energy storage stage and transport it through the inlet pipeline of the energy storage stage pipeline to the throttle expansion valve;

[0021] 3) The throttle expansion valve causes the liquid carbon dioxide to rapidly depressurize and cool. The liquid carbon dioxide is sprayed through the multi-point injection head of the throttle expansion valve to the inlet of the energy storage stage, and the pressure drops rapidly. The pressure of the liquid CO2 is used to regulate and control the temperature reduction, forming solid carbon dioxide and a small amount of gaseous carbon dioxide in the closed high-pressure storage tank, and realizing the phase change in the closed high-pressure storage tank;

[0022] 4) The solid carbon dioxide gradually accumulates in the closed high-pressure storage tank to achieve high-density energy storage. The solid carbon dioxide is directly collected and stored in the closed high-pressure storage tank, and the gaseous carbon dioxide is transmitted to the energy storage stage pipeline under the control of the first switch valve through the outlet of the energy storage stage;

[0023] b) Energy release stage:

[0024] 1) The pressure of the liquid carbon dioxide is increased by the hydraulic pump in the energy release stage;

[0025] 2) Open the inlet switch valve in the energy release stage, and inject the high-pressure liquid carbon dioxide into the inlet of the energy release stage of the closed high-pressure storage tank, triggering the heating and partial phase change of the solid carbon dioxide, and further providing conditions for the generation of high-pressure carbon dioxide;

[0026] 3) The carbon dioxide in the three-phase state of solid, liquid and gas is sprayed out from the outlet of the energy release stage of the closed high-pressure storage tank to the energy release stage pipeline under the control of the second switch valve;

[0027] 4) The high-pressure gaseous carbon dioxide is transported to the gas-driven generator. The gaseous carbon dioxide pushes the turbine to rotate, converting the pressure energy and thermal energy of the gas into mechanical energy, and outputting electric energy through the gas-driven generator.

[0028] Among them, in step 1) of step a), the pressure of the liquid carbon dioxide is increased to 4 - 8 MPa after passing through the hydraulic pump in the energy storage stage.

[0029] In step 3) of step a), the injection rate is controlled at 0.2 kg / s - 3 kg / s to ensure the best phase change effect. The temperature is reduced to -57°C.

[0030] In step 1) of step b), the pressure of the liquid carbon dioxide is increased to 6 - 12 MPa after passing through the hydraulic pump in the energy release stage.

[0031] In step 2) of step b), the mixing ratio of the liquid carbon dioxide to the solid carbon dioxide is 1:1 - 10:1, which can be dynamically adjusted, and the specific ratio is controlled according to the real-time energy release demand.

[0032] A heat exchange device is provided at the inlet of the gas-driven generator. The heat exchange device uses industrial waste heat or solar energy to heat high-pressure gaseous carbon dioxide to 100°C to 200°C, so as to improve the power generation efficiency.

[0033] Advantages of the present invention:

[0034] In the present invention, a plurality of injection expansion valves are uniformly arranged on the side wall of the closed high-pressure storage tank. During the energy storage stage, liquid carbon dioxide is expanded and transformed into solid carbon dioxide and stored in the closed high-pressure storage tank. During the energy release stage, solid carbon dioxide is transformed into high-pressure gaseous carbon dioxide to drive the gas-driven generator to generate electricity, completing the high-density storage and high-efficiency release of energy; after the energy release, carbon dioxide is re-liquefied through compression and cooling and returned to the liquid storage tank, forming a closed-loop cycle between liquid-solid-gas, realizing the storage of solid carbon dioxide; the entire cycle process is designed to be efficient, safe and environmentally friendly, reducing carbon dioxide leakage or waste, reflecting an innovative solution to meet future energy storage needs. Description of the drawings

[0035] Figure 1 It is the front view of an embodiment of the integrated solid carbon dioxide energy storage and energy release device of the present invention;

[0036] Figure 2 It is the side view of an embodiment of the integrated solid carbon dioxide energy storage and energy release device of the present invention;

[0037] Figure 3 It is the bottom view of an embodiment of the integrated solid carbon dioxide energy storage and energy release device of the present invention;

[0038] Figure 4 It is the schematic diagram of the energy storage stage of an embodiment of the integrated solid carbon dioxide energy storage and energy release device of the present invention;

[0039] Figure 5 It is the schematic diagram of the energy release stage of an embodiment of the integrated solid carbon dioxide energy storage and energy release device of the present invention. Detailed implementation manners

[0040] The present invention will be further described below with reference to the drawings through specific embodiments.

[0041] Such as Figure 1As shown in the figure, the integrated solid carbon dioxide energy storage and release device of this embodiment includes: a closed high-pressure storage tank, an energy storage stage inlet, an injection expansion valve, an energy storage stage inlet switch valve, an energy storage stage hydraulic pump, an energy storage stage outlet, a first switch valve, an energy release stage inlet, an energy release stage inlet switch valve, an energy release stage hydraulic pump, an energy storage stage outlet, a second switch valve, a temperature sensor, a force sensor, an energy storage stage pipeline, and an energy release stage pipeline; among them, the closed high-pressure storage tank is a closed cylindrical shell with a space inside, placed upright, that is, the central axis of the cylinder is in the vertical direction; a plurality of uniformly distributed energy storage stage inlets are opened in the circumferential direction of the side wall of the closed high-pressure storage tank, an energy storage stage inlet switch valve is arranged in front of each energy storage stage inlet, an injection expansion valve is arranged in each energy storage stage inlet, and the injection head of the injection expansion valve is located on the inner wall of the closed high-pressure storage tank; an energy storage stage outlet is opened at the top of the closed high-pressure storage tank, and a first switch valve is arranged at the energy storage stage outlet; an energy release stage inlet is opened on the side wall of the closed high-pressure storage tank, and an energy release stage inlet switch valve is arranged in front of the energy release stage inlet; an energy release stage outlet is opened at the bottom, and a second switch valve is arranged at the energy release stage outlet; temperature sensors and force sensors are arranged on both the second switch valve and the first switch valve to monitor the temperature and pressure of the closed high-pressure storage tank during the energy storage stage and the energy release stage;

[0042] A plurality of energy storage stage inlet pipelines are respectively connected to the corresponding energy storage stage inlets, the energy storage stage outlet is connected to the energy storage stage outlet pipeline, and a compressor is arranged on the energy storage stage outlet pipeline; an energy storage stage pipeline is connected between the energy storage stage inlet pipeline and the energy storage stage outlet pipeline; an energy storage stage hydraulic pump is arranged on the energy storage stage inlet pipeline; the energy release stage inlet pipeline is connected to the energy release stage inlet, the energy release stage outlet is connected to the energy release stage outlet pipeline, and an energy release stage pipeline is connected between the energy release stage inlet pipeline and the energy release stage outlet pipeline; an energy release stage hydraulic pump is arranged on the energy release stage inlet pipeline; a turbine is arranged on the energy release stage pipeline; the ends of the energy storage stage pipeline and the energy release stage pipeline are respectively connected to two inlets of a liquid storage tank, and the liquid storage tank is a container for storing liquid carbon dioxide, operating under low temperature and high pressure conditions to ensure that the liquid carbon dioxide is in a stable state, and the liquid carbon dioxide is stored in the liquid storage tank; a plurality of energy storage stage outlets of the liquid storage tank are respectively connected to the corresponding energy storage stage inlet pipelines, and the energy release stage outlet of the liquid storage tank is connected to the energy release stage inlet pipeline.

[0043] The control method of the integrated solid carbon dioxide energy storage and release device of this embodiment includes the following steps:

[0044] a) Energy storage stage:

[0045] 1) Turn on the hydraulic pump in the energy storage stage and turn off the hydraulic pump in the energy release stage; open the first switching valve at the energy storage stage outlet of the solid-state storage tank and close the second switching valve at the energy release outlet of the solid-state storage tank; open the inlet switching valve in the energy storage stage and close the inlet switching valve in the energy release stage; liquid carbon dioxide at a temperature of -20°C and a pressure of 5 Mpa is pressurized at a rate of about 0.3 kg / s to 2 kg / s by the hydraulic pump in the energy storage stage.

[0046] 2) Transport it through the inlet pipeline of the energy storage stage pipeline to the throttle expansion valve.

[0047] 3) The throttle expansion valve rapidly reduces the pressure and cools the liquid carbon dioxide to a pressure of 0.5 MPa and a temperature of -57°C. The liquid carbon dioxide is sprayed through the multi-point spray head of the throttle expansion valve to the inlet of the energy storage stage. The diameter of the spray head is 8 mm to 70 mm, and the pressure rapidly drops. The pressure of the liquid CO2 is used to regulate and control the temperature reduction. 40% to 60% of the liquid carbon dioxide is converted into solid carbon dioxide and a small amount of gaseous carbon dioxide in the closed high-pressure storage tank, and a phase change is achieved in the closed high-pressure storage tank; the temperature in the closed high-pressure storage tank is -57°C, the pressure is 0.5 MPa, and 2000 kg of solid carbon dioxide is stored.

[0048] 4) Solid carbon dioxide gradually accumulates in the closed high-pressure storage tank to achieve high-density energy storage. The solid carbon dioxide is directly collected and stored in the closed high-pressure storage tank. Open the first switching valve, and the gaseous carbon dioxide generated after expansion in the closed high-pressure storage tank is introduced into the compressor for compression and then flows back to the liquid storage tank through the energy storage stage pipeline to achieve gas recovery and recycling.

[0049] b) Energy release stage:

[0050] 1) Turn on the hydraulic pump in the energy release stage and turn off the hydraulic pump in the energy storage stage; open the second switching valve at the energy release outlet of the solid-state storage tank and close the first switching valve at the energy storage stage outlet of the solid-state storage tank; open the inlet switching valve in the energy release stage and close the inlet switching valve in the energy storage stage; liquid carbon dioxide at a temperature of -20°C and a pressure of 8 MPa is pressurized by the hydraulic pump in the energy release stage.

[0051] 2) Dynamically adjust the mixing ratio of liquid carbon dioxide to solid carbon dioxide to 1:1 to 10:1. The high-pressure liquid carbon dioxide is injected into the energy release stage inlet of the closed high-pressure storage tank, and the injection rate is controlled at 0.2 kg / s to 2 kg / s. The temperature is reduced to -57°C, triggering the heating and partial phase change of the solid carbon dioxide, further providing conditions for the generation of high-pressure carbon dioxide.

[0052] 3) The carbon dioxide in the three-phase state of solid, liquid and gas is ejected from the energy release stage outlet with a diameter of 10 mm to 50 mm of the closed high-pressure storage tank to the energy release stage pipeline under the control of the second switching valve, and passes through a heating and heat exchange device on the energy release stage pipeline to heat the high-pressure carbon dioxide to 100°C to 200°C by using industrial waste heat or solar energy;

[0053] 4) The high-pressure gaseous carbon dioxide is transported to the turbine, and the gaseous carbon dioxide drives the turbine to rotate, converting the pressure energy and thermal energy of the gas into mechanical energy, and generating electric energy through the turbine;

[0054] 5) The gaseous carbon dioxide after energy release is cooled and liquefied through a multi-stage cooling device to ensure that the energy loss of the carbon dioxide after energy release is less than 10% during the cooling process, and then flows back to the liquid carbon dioxide storage tank to form a closed-loop cycle.

[0055] Finally, it should be noted that the purpose of disclosing the embodiments is to help further understand the present invention. However, those skilled in the art can understand that various substitutions and modifications are possible without departing from the spirit and scope of the present invention and the appended claims. Therefore, the present invention should not be limited to the content disclosed in the embodiments, and the scope of protection claimed by the present invention shall be subject to the scope defined by the claims.

Claims

1. A solid carbon dioxide energy storage and release integrated device, characterized in that: The solid carbon dioxide energy storage and release integrated device comprises: a closed high-pressure storage tank, an energy storage stage inlet, an injection expansion valve, an energy storage stage inlet switch valve, an energy storage stage hydraulic pump, an energy storage stage outlet, a first switch valve, an energy release stage inlet, an energy release stage inlet switch valve, an energy release stage hydraulic pump, an energy storage stage outlet, a second switch valve, an energy storage stage pipeline and an energy release stage pipeline; wherein the closed high-pressure storage tank is a closed cylindrical shell with a space inside, placed upright, that is, the central axis of the cylinder is in the vertical direction; the side wall of the closed high-pressure storage tank is provided with a circumferential One or more evenly distributed energy storage stage inlets, an energy storage stage inlet switch valve is arranged in front of each energy storage stage inlet, an injection expansion valve is arranged in each energy storage stage inlet, and the injection head of the injection expansion valve is located on the inner wall of the closed high-pressure storage tank; an energy storage stage outlet is opened at the top of the closed high-pressure storage tank, and a first switch valve is arranged at the energy storage stage outlet; an energy release stage inlet is opened on the side wall of the closed high-pressure storage tank, and an energy release stage inlet switch valve is arranged in front of the energy release stage inlet; an energy release stage outlet is opened at the bottom, and a second switch valve is arranged at the energy release stage outlet; Each energy storage stage inlet pipeline is connected to the corresponding energy storage stage inlet, the energy storage stage outlet is connected to the energy storage stage outlet pipeline, and the energy storage stage pipeline is connected between the energy storage stage inlet pipeline and the energy storage stage outlet pipeline; an energy storage stage hydraulic pump is arranged on each energy storage stage inlet pipeline; the energy release stage inlet pipeline is connected to the energy release stage inlet, the energy release stage outlet is connected to the energy release stage outlet pipeline, and the energy release stage pipeline is connected between the energy release stage inlet pipeline and the energy release stage outlet pipeline; an energy release stage hydraulic pump is arranged on the energy release stage inlet pipeline; and a gas-driven generator is arranged on the energy release stage pipeline.

2. The solid carbon dioxide energy storage and release integrated device according to claim 1, characterized in that: It also includes a liquid storage tank, which is respectively connected to two inlets of the liquid storage tank at the ends of the energy storage stage pipeline and the energy release stage pipeline, one or more energy storage stage outlets of the liquid storage tank are respectively connected to the corresponding one or more energy storage stage inlet pipelines, and the energy release stage outlet of the liquid storage tank is connected to the energy release stage inlet pipeline.

3. The solid carbon dioxide energy storage and release integrated device according to claim 2, characterized in that: It also includes a compressor. A compressor is arranged on the outlet pipeline of the energy storage stage. The gaseous carbon dioxide generated after expansion in the closed high-pressure storage tank is introduced into the compressor for compression, and then flows back to the liquid storage tank through the pipeline of the energy storage stage, thereby realizing gas recovery and circulation.

4. The solid carbon dioxide energy storage and release integrated device according to claim 1, characterized in that: The injection head diameter of the injection expansion valve is 8 mm to 70 mm.

5. The solid carbon dioxide energy storage and release integrated device according to claim 1, characterized in that: It also includes a temperature rising heat exchange device and a multi-stage cooling device. The temperature rising heat exchange device is respectively arranged on the energy storage stage pipeline and after the compressor, and on the energy release stage pipeline and before the gas driven generator to heat the carbon dioxide. Before the energy storage stage pipeline and the energy release stage pipeline enter the liquid storage tank, a multi-stage cooling device is arranged to gradually cool down and liquefy the gaseous carbon dioxide, and return it to the liquid storage tank for storage.

6. The solid carbon dioxide energy storage and release integrated device according to claim 1, characterized in that: It also includes a temperature sensor and a force sensor, which are arranged on the second switch valve and the first switch valve.

7. A control method for a solid carbon dioxide energy storage and release integrated device as claimed in claim 1, characterized in that: The control method comprises the following steps: a) Energy storage stage: 1) Liquid carbon dioxide is increased in pressure by a hydraulic pump during the energy storage phase; 2) Open the inlet switch valve of the energy storage stage and transport it to the throttling expansion valve through the inlet pipeline of the energy storage stage pipeline; 3) The throttling expansion valve causes the liquid carbon dioxide to be rapidly depressurized and cooled. The liquid carbon dioxide is sprayed to the entrance of the energy storage stage through the multi-point spray head of the throttling expansion valve. The pressure drops rapidly. The pressure of the liquid CO2 is used to adjust and control the temperature to decrease. Solid carbon dioxide and a small amount of gaseous carbon dioxide are formed in the closed high-pressure storage tank, and a phase change is achieved in the closed high-pressure storage tank. 4) Solid carbon dioxide gradually accumulates in the closed high-pressure storage tank to achieve high-density energy storage. Solid carbon dioxide is directly collected and stored in the closed high-pressure storage tank, and gaseous carbon dioxide is transmitted to the energy storage stage pipeline through the energy storage stage outlet under the control of the first switch valve; b) Energy release stage: 1) Liquid carbon dioxide increases in pressure through the hydraulic pump during the energy release phase; 2) Open the energy release stage inlet switch valve, and inject high-pressure liquid carbon dioxide into the energy release stage inlet of the closed high-pressure storage tank, causing the solid carbon dioxide to heat up and partially change its phase, further providing conditions for the generation of high-pressure carbon dioxide; 3) The solid, liquid and gaseous three-phase mixed carbon dioxide is ejected from the energy release stage outlet of the closed high-pressure storage tank to the energy release stage pipeline under the control of the second switch valve; 4) The high-pressure gaseous carbon dioxide is transported to the gas-driven generator, which drives the turbine to rotate, converting the pressure energy and thermal energy of the gas into mechanical energy, and outputting electrical energy through the gas-driven generator.

8. The control method according to claim 7, characterized in that: In step a) 1), the pressure of the liquid carbon dioxide is increased to 4-8 MPa after passing through the hydraulic pump in the energy storage stage.

9. The control method according to claim 7, characterized in that: In step b) 1), the pressure of the liquid carbon dioxide is increased to 6-12 MPa after passing through the hydraulic pump in the energy release stage.

10. The control method according to claim 7, characterized in that: In step b) 2), the mixing ratio of liquid carbon dioxide to solid carbon dioxide is 1:1 to 10:1.

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