A pressure-stage hydraulic compressed air energy storage system with supplemental heating and its operation method

Abstract

This invention discloses a pressure-stage hydraulic compressed air energy storage system with supplemental heating and its operation method, belonging to the field of energy storage technology. In this system, the design of the supplemental heating unit enables the system to fully utilize external heat sources to supplement the heating of the high-pressure air storage container and the steam-water mixing container. During the air expansion and work process, the supplemental heating can maintain or increase the temperature of the working fluid, thereby maintaining or increasing the work capacity and effectively improving the energy conversion efficiency of the system. The use of the pressure-stage steam-water mixing container not only optimizes the energy storage and release process, but also improves the flexibility and stability of the system. The energy conversion unit can ensure the stable operation of the system's energy storage and power generation processes. The use of this system can realize the full utilization of low-grade waste heat resources, increase power generation, and improve the system's cycle efficiency. It has multiple advantages such as high efficiency, flexibility, and stability, which is of great significance for promoting the utilization of clean energy and the stable operation of the power grid.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of energy storage, and relates to the field of hydraulic compressed air energy storage systems, in particular to a pressure grading hydraulic compressed air energy storage system with heat supplement. BACKGROUND

[0002] The compressed air energy storage system plays an indispensable important role in the modern energy field. It not only provides an effective means for large-scale and long-time storage of renewable energy (such as solar energy and wind energy), but also can quickly release energy during the peak of power demand to balance the supply and demand fluctuations of the power grid. This energy storage technology not only improves energy utilization efficiency, but also helps to promote the development of green energy and provides strong support for achieving the carbon neutralization goal. By reducing the dependence on fossil energy and carbon emissions, the compressed air energy storage system makes an important contribution to building a sustainable and environmentally friendly energy system.

[0003] At present, the existing non-reheat compressed air energy storage working medium and energy storage medium are all air, and the start-stop process takes more than ten minutes, and the power increasing and decreasing rate is slow. There is a large amount of low-temperature (40℃-150℃) low-grade waste heat in the industrial field, such as flue gas discharged by boilers (heating furnaces), which is generally at 140-180℃; the water for flushing blast furnace slag and steelmaking slag, which is at 60-90℃; the circulating cooling water, which is mostly at 30-50℃; and the oilfield produced water, which is at 30-60℃. Due to the low energy grade of this part of waste heat, there are problems such as low efficiency, low economic benefit, and immature technology when used for power generation, and at present, there is generally a lack of efficient utilization means, and it is often directly discarded. The current non-reheat compressed air energy storage lacks waste heat recovery function, and cannot recycle low-grade waste heat resources, affecting the cycle efficiency of the entire system.

[0004] Therefore, the existing hydraulic compressed air energy storage system lacks waste heat recovery function, cannot recycle low-grade waste heat resources, and affects the cycle efficiency of the entire system. SUMMARY

[0005] The present application aims to provide a pressure grading hydraulic compressed air energy storage system with heat supplement to solve the problem that the existing hydraulic compressed air energy storage system lacks waste heat recovery function, cannot recycle low-grade waste heat resources, and affects the cycle efficiency of the entire system.

[0006] In order to achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0007] A pressure grading hydraulic compressed air energy storage system with heat supplement, comprising a heat supplement unit, a high-pressure gas storage container, a plurality of connected steam-water mixed containers, and an energy conversion unit for supplementing liquid to the steam-water mixed containers and generating electricity;

[0008] The air outlets of the high-pressure gas storage containers are connected to the steam-water mixing containers respectively;

[0009] The water inlets and water outlets of the steam-water mixing containers are connected to the energy conversion units respectively;

[0010] The heat supplement units are connected to the high-pressure gas storage containers and the steam-water mixing containers respectively, and are used for supplementing heat for the high-pressure gas storage containers and the steam-water mixing containers;

[0011] The input port of the heat supplement unit is communicated with an external heat source.

[0012] Further, the high-pressure gas storage containers are multiple, and the multiple high-pressure gas storage containers are connected in sequence through valves; the high-pressure gas storage containers are connected to the output ports of the heat supplement units respectively, and are connected to the steam-water mixing containers one by one respectively.

[0013] Further, the high-pressure gas storage containers are different in pressure grade.

[0014] Further, the steam-water mixing containers are different in pressure grade.

[0015] Further, the heat supplement unit is a heat exchanger; a first heat supplement port of the heat exchanger is connected to the high-pressure gas storage container, and a second heat supplement port is connected to the steam-water mixing containers respectively.

[0016] Further, the air outlet of the high-pressure gas storage container is connected to the input port of the heat exchanger.

[0017] Further, the energy conversion unit comprises a water turbine and a water pump; the water turbine is connected to the water outlets of the steam-water mixing containers; the water pump is connected to the water inlets of the steam-water mixing containers; the water turbine and the water pump are connected to a water storage pool respectively.

[0018] Further, the energy conversion unit is a pump turbine; the water outlet of the steam-water mixing container is the same as the water inlet; one end of the pump turbine is connected to the steam-water mixing containers, and the other end is connected to the water storage pool.

[0019] A running method of a pressure grading water hydraulic compressed air energy storage system with heat supplement, based on the pressure grading water hydraulic compressed air energy storage system with heat supplement, comprising:

[0020] In the power generation stage, the high-pressure gas storage containers supplement air for the steam-water mixing containers, the air drives the water working medium in the steam-water mixing containers to work after expansion, and drives the energy conversion unit to generate electricity; in the power generation process, the heat supplement units supplement heat for the high-pressure gas storage containers and the steam-water mixing containers respectively;

[0021] In the energy storage stage, the energy conversion unit supplies liquid to each steam-water mixing container, atomizes and sprays to reduce the temperature of compressed air, until the steam-water mixing container and the high-pressure gas storage container reach the corresponding preset pressure values.

[0022] Further, when the gas outlet of the high-pressure gas storage container is in communication with the gas source input port of the heat supplement unit, the high-pressure gas storage container inputs air to the heat supplement unit for heat exchange.

[0023] Compared with the prior art, the present application has the following beneficial effects:

[0024] The present application provides a pressure-staged water hydraulic compressed air energy storage system with heat supplement, which comprises a heat supplement unit, a high-pressure gas storage container, a plurality of steam-water mixing containers and an energy conversion unit. The design of the heat supplement unit enables the system to fully utilize external heat sources to supplement the high-pressure gas storage container and the steam-water mixing containers. During the air expansion work process, the heat supplement can maintain or improve the temperature of the working medium, thereby maintaining or increasing the work capacity, effectively improving the energy conversion efficiency of the system. The use of pressure-staged steam-water mixing containers not only optimizes the energy storage and release process, but also improves the flexibility and stability of the system. The energy conversion unit can ensure the stable operation of the system during energy storage and power generation. The use of the present system can fully utilize low-grade waste heat resources, increase power generation and improve system cycle efficiency, with multiple advantages such as high efficiency, flexibility and stability, which is of great significance for promoting the use of clean energy and the smooth operation of the power grid.

[0025] Preferably, in the present application, by connecting a plurality of high-pressure gas storage containers in series, the system can store more compressed air, increasing the energy storage capacity. At the same time, the pressure of the energy storage container and the pressure of the working container are decoupled, significantly reducing the demand for large volume of high-pressure storage containers in the energy storage system.

[0026] Further preferably, in the present application, the high-pressure gas storage container can adapt to different energy storage and power generation demands by using different pressure levels, improving the adaptability of the system. Graded storage can also improve the safety of the system and reduce the risk of excessive pressure.

[0027] Preferably, in the present application, the steam-water mixing container can store and release energy during a large pressure change process by using different pressure levels, significantly reducing the cost of the container during energy storage and power generation, and improving the technical and economic efficiency of the system.

[0028] Preferably, in the present application, the heat supplement unit uses a heat exchanger, the input port of which is in communication with an external heat source, which can fully utilize low-grade waste heat resources and ensure the improvement of power generation and system cycle efficiency.

[0029] Further preferably, in the application, the gas outlet of the high-pressure gas storage container is connected with the input port of the heat exchanger, and after the power generation is completed, the atomized cooling water in the high-pressure gas storage container is transported into the steam-water mixing container through the heat exchanger through a pipeline, thereby improving the liquid supplementing efficiency in the energy storage process and realizing the internal circulation of the whole system and the reuse of the working medium.

[0030] Preferably, in the application, the energy conversion unit comprises a water turbine and a water pump, the water turbine can convert the kinetic energy of the water working medium into mechanical energy and then into electric energy, and the water pump is used for supplementing the steam-water mixing container with liquid to ensure the normal operation of the system.

[0031] Preferably, in the application, the water pump water turbine combines the functions of the water pump and the water turbine, has the advantages of fast speed in the start-stop process and short switching time, and enables the system to realize efficient energy conversion in the energy storage and power generation processes.

[0032] The application also provides a running method of the pressure grading water power compressed air energy storage system with heat supplement, which is based on the above-mentioned pressure grading water power compressed air energy storage system with heat supplement.

[0033] Preferably, in the application, when the gas outlet of the high-pressure gas storage container is communicated with the gas source input port of the heat supplement unit, the high-pressure gas storage container inputs air to the heat supplement unit for heat exchange, so that the air output by the high-pressure gas storage container can directly enter the heat supplement unit for heat exchange, further reducing energy loss and improving the overall efficiency of the system. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 A structure schematic diagram of the pressure grading water power compressed air energy storage system with heat supplement provided by the application is shown in the figure.

[0035] Figure 2 A structure schematic diagram of the pressure grading water power compressed air energy storage system with heat supplement provided by the embodiment of the application is shown in the figure.

[0036] Figure 3 Another structure schematic diagram of the pressure grading water power compressed air energy storage system with heat supplement provided by the embodiment of the application is shown in the figure.

[0037] REFERENCE SIGNS:

[0038] High pressure gas storage container-1; first high pressure gas storage container-1-1; second high pressure gas storage container-1-2; third high pressure gas storage container-1-3; Nth high pressure gas storage container-1-4;

[0039] Steam-water mixing container-2; first steam-water mixing container-2-1; second steam-water mixing container-2-2; third steam-water mixing container-2-3; Nth steam-water mixing container-2-4;

[0040] Water turbine-3; water pump-4; water reservoir-5; heat exchanger-6; first manifold-7; second manifold-8; third manifold-9; fourth manifold-10; fifth manifold-11; sixth manifold-12. DETAILED DESCRIPTION

[0041] In order to make the technical problems solved by the present application, technical solutions and beneficial effects clearer, the following specific embodiments are used to further describe the present application in detail. It should be understood that the specific embodiments described here are only used to explain the present application, and are not used to limit the present application.

[0042] In order to make the technical problems solved by the present application, technical solutions and beneficial effects clearer, the following specific embodiments are used to further describe the present application in detail. It should be understood that the specific embodiments described here are only used to explain the present application, and are not used to limit the present application.

[0043] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but only represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work are within the scope of protection of the present application.

[0044] It should be noted that: similar numbers and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0045] In the description of the embodiments of the present application, it should be noted that if the terms "upper", "lower", "horizontal", "inner" and the like indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, or the orientation or position relationship when the product of the present application is commonly placed, which is only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as limiting the device or element indicated to have a specific orientation, to be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second" and the like are only used for differentiation and cannot be understood as indicating or implying relative importance.

[0046] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly inclined. For example, "horizontal" only means that its direction is relatively more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0047] In the description of the embodiments of the present application, it should be noted that unless otherwise explicitly specified and limited, if the terms "arrangement", "installation", "connection", "connection" appear, they should be understood in a broad sense, for example, they can be fixedly connected, or can be detachably connected, or integrally connected; can be mechanically connected, or can be electrically connected; can be directly connected, or indirectly connected through an intermediate medium; can be connected inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0048] Embodiment 1

[0049] As mentioned in the background, the existing non-reheat compressed air energy storage working medium and energy storage medium are both air, and the start-stop process takes more than ten minutes, and the power increasing and decreasing rate is slow; There is a lot of low-temperature (40℃-150℃) low-grade waste heat in the industrial field, such as flue gas discharged by boilers (heating furnaces), which is generally at 140-180℃; The water for flushing slag from blast furnace slag and steelmaking slag is at a temperature of 60-90℃; Most of the circulating cooling water is at 30-50℃; The oilfield produced water is at 30-60℃. Due to the low energy grade of this part of waste heat, there are problems such as low efficiency, low economic benefit and immature technology when used for power generation, and at present, there is generally a lack of efficient utilization means, and it is often directly discarded; However, the current non-reheat compressed air energy storage lacks waste heat recovery function, and cannot utilize low-grade waste heat resources, which affects the cycle efficiency of the entire system.

[0050] In order to solve the above problems, the present embodiment provides a pressure staged water power compressed air energy storage system with heat supplement, which adds a waste heat recovery function, can fully utilize low-grade waste heat resources, and can improve the cycle efficiency of the entire system by using the system and method.

[0051] AsFigure 1 As shown, the present application provides a pressure grading heat-supplemented hydraulic compressed air energy storage system, which comprises a heat-supplementing unit, and in this embodiment, a heat exchanger 6 is adopted, the first heat-supplementing port of the heat exchanger 6 is connected with a high-pressure gas storage container 1, and the second heat-supplementing port is respectively connected with a plurality of steam-water mixing containers 2 (steam-water mixing containers G1, G2…G N ); the plurality of steam-water mixing containers 2 are connected in series through valves; the high-pressure gas storage container 1 is respectively connected with each steam-water mixing container 2 through a valve; and the system further comprises an energy conversion unit, wherein the energy conversion unit adopts a water turbine 3 and a water pump 4, the water turbine 3 is connected with the water outlet of each steam-water mixing container 2 and is used for generating power; the water pump 4 is connected with the water inlet of each steam-water mixing container 2 and is used for supplementing liquid to the steam-water mixing container 2 to complete energy storage; the water turbine 3 is coaxially connected with a generator, and the water pump 5 is coaxially connected with a water pump motor.

[0052] In this embodiment, each steam-water mixing container 2 adopts a high-pressure gas storage container with different pressure grades and different volumes, which can realize energy storage and release in a large pressure change process, significantly reduces the container cost in the energy storage and power generation process, and improves the technical economy of the system.

[0053] This embodiment provides a pressure grading heat-supplemented hydraulic compressed air energy storage system, and the working principle is as follows:

[0054] Specifically, the system includes a power generation phase and an energy storage phase:

[0055] In the energy storage phase, the water pump 4 pumps water from the water storage pool 5 to supplement the liquid of each steam-water mixing container 2 to realize energy storage, until the steam-water mixing container 2 and the high-pressure gas storage container 1 both reach the corresponding preset pressure value, and the energy storage ends.

[0056] In the power generation phase, the high-pressure gas storage container 1 supplies air to each steam-water mixing container 2, and the air pushes the water working medium in the steam-water mixing container 2 to do work after expansion, driving the generator connected with the water turbine 3 to generate power; in the power generation process, the heat exchanger 6 supplements heat for the high-pressure gas storage container 1 and the steam-water mixing container 2 respectively; in this way, the heat exchanger 6 fully utilizes the external heat source to supplement heat for the high-pressure gas storage container 1 and the steam-water mixing container 2 in the power generation process, improves the energy conversion efficiency, and increases the power generation efficiency.

[0057] In this embodiment, in order to realize efficient energy conversion of the system in the energy storage and power generation process, the energy conversion unit adopts a water pump water turbine; the water pump water turbine combines the functions of a water pump and a water turbine, and has the advantages of fast speed in the start-stop process and short switching time.

[0058] Embodiment 2

[0059] This embodiment provides another pressure-stage hydraulic compressed air energy storage system with heat compensation. The structure is the same as in Embodiment 1, but with further optimizations and improvements based on the structure of Embodiment 1, specifically including:

[0060] like Figure 2 As shown, in this embodiment, multiple high-pressure gas storage containers 1 are connected in series and linked to each other by valves. Specifically, they include a first high-pressure gas storage container 1-1, a second high-pressure gas storage container 1-2, a third high-pressure gas storage container 1-3, and an Nth high-pressure gas storage container 1-4; B1, B2…B N (1≤N≤200000), connected via valves to the corresponding first carbonated water mixing container 2-1, second carbonated water mixing container 2-2, third carbonated water mixing container 2-3, and Nth carbonated water mixing container 2-4, i.e., carbonated water mixing containers G1, G2…G N (1≤N≤200000); High-pressure gas storage container B i-1 (1≤i≤N) and high-pressure gas storage container B i (1≤i≤N) are connected in pairs via valves; Flour mixing container G i-1 (1≤i≤N) and the soda / water mixing container G i (1≤i≤N) are connected in pairs via valves; Flour mixing container G i (1≤i≤N) is connected to the sixth manifold 12 via a valve. The sixth manifold 12 is connected to the outlet of the water pump 4. The inlet of the water pump 4 is connected to the water storage tank 5.

[0061] During power generation, heat exchanger 6 is connected to the first manifold 7 and the second manifold 8. The first manifold 7 is connected to multiple high-pressure gas storage containers B1, B2...B through valves. N (1≤N≤200000) connection, the second manifold 8 connects to multiple steam-water mixing containers G1, G2…G through valves. N Connect multiple high-pressure gas storage containers B1, B2…B N (1≤N≤200000) Connected to the soda-water mixing containers G1, G2…G through the third manifold 9 and the fourth manifold 10. N (1≤N≤200000), Soft drink mixing container G i (1≤i≤N) is connected to the fifth manifold 11 through a valve. The fifth manifold 11 is connected to the inlet of the water turbine 3. The outlet of the water turbine 3 is connected to the water storage tank 5.

[0062] During power generation, the external heat source passes through heat exchangers 6 pairs of high-pressure gas storage containers B1, B2...B N (1≤N≤200000) and various levels of soda-water mixing containers G1, G2…G NThe air in (1≤N≤200000) is heated to reduce the temperature drop and pressure reduction of each stage of high-pressure gas storage container and each stage of steam-water mixing container during the power generation process.

[0063] Among them, the high-pressure gas storage container 1 uses multiple containers with different pressures and volumes to achieve the storage and release of energy during large pressure changes. The pressure levels of the high-pressure gas storage container 1 are B1>B2>…B N The carbonated beverage mixing container uses multiple containers of varying pressures and volumes to store and release energy during significant pressure changes. The pressure ratings of the carbonated beverage mixing container are G1>G2>…G N .

[0064] After the first i (1≤i≤N) high-pressure gas storage containers 1 expand and generate electricity for the first i (1≤i≤N) steam-water mixing containers 2, the gas pressure value is equal to the gas pressure value inside the (i+1)th (1≤i≤N-1)th high-pressure gas storage container. During the gas expansion and power generation process of the i (1≤i≤N)th steam-water mixing container connected to the turbine, the first i (1≤i≤N) high-pressure gas storage containers and the first i-1th steam-water mixing containers replenish gas to the i (1≤i≤N)th steam-water mixing container. The external heat source simultaneously replenishes the air in the first i (1≤i≤N) high-pressure gas storage containers, the air in the first i-1th steam-water mixing containers, and the air in the i (1≤i≤N)th steam-water mixing container through the heat exchanger.

[0065] During the energy storage process, after the i-th (1≤i≤N) gas-water mixing container finishes pumping and pressurizing for energy storage, the first N-i+1 high-pressure gas storage containers B i (1≤i≤N-i+1) and the soda mixing container G i The air pressure values ​​are equal within the range (1≤i≤N-i+1).

[0066] During the energy storage process, water pump 4 first pumps the gas-water mixing container G, which has a low pressure resistance. N Liquid is replenished, at which time high-pressure gas storage containers B1, B2...B N (1≤N≤200000) and each soda-water mixing container G N-1 G N-2 …G1 are interconnected, and the low-pressure steam-water mixing container G… N Once the internal air pressure reaches the set value, the valve is closed, and the connection between the high-pressure air storage container B and the water tank and other containers is cut off. N Close the valve, disconnect from the high-pressure gas storage container and other containers, and then use a water pump to sequentially pump the low-pressure steam-water mixing container G. N-1 Pumping and pressurization, high-pressure gas storage containers B1, B2…B N-1 and various soda mixing containers G N-2 …G1 connection, until the soda mixing container G…N-1 Once the internal air pressure reaches the set value, the valve is closed, and the connection between the high-pressure air storage container B and the water tank and other containers is cut off. N-1 Close the valve and disconnect the connection between the high-pressure gas storage container and other containers; continue this process until, before the Nth energy storage, the high-pressure gas storage container B1 and the steam-water mixing container G1 are connected. After the water pump 4 pumps water into the steam-water mixing container G1 to increase the pressure, the gas pressure in the high-pressure gas storage container B1 reaches the set value, and the energy storage process ends.

[0067] Example 3

[0068] This embodiment provides another pressure-stage hydraulic compressed air energy storage system with heat compensation. The structure is the same as in Embodiment 2, but with further optimizations and improvements based on the structure of Embodiment 2, specifically including:

[0069] like Figure 3 As shown, in this embodiment, the outlet of each high-pressure gas storage container 1 is connected to the inlet of the heat exchanger 6. After power generation is completed, the air in the high-pressure gas storage container is atomized to form cooling water, which is then fed into the gas-water mixing container through the heat exchanger 6. This improves the liquid replenishment efficiency during the energy storage process and realizes the internal circulation and reuse of the working fluid of the entire system.

[0070] In addition, in the above embodiments, the gas-water mixing container and the high-pressure gas storage container can adopt forced heat exchange technology such as atomized spraying during the energy storage process, so as to achieve an approximately constant air temperature during the energy storage process.

[0071] Furthermore, throughout the entire energy storage-power generation cycle, the gas in the high-pressure gas storage container and each gas-water mixing container does not directly contact the atmospheric environment, forming a closed system that ensures the stable operation of the system.

[0072] In summary, this invention provides a pressure-staged hydraulic compressed air energy storage system with supplemental heating. Compared with existing hydraulic compressed air energy storage systems, this method has the following advantages:

[0073] a) This invention achieves energy storage and power generation through the compression and expansion of air, realizing energy storage and power generation without terrain difference, and has the advantage of flexible layout.

[0074] b) This invention achieves the decoupling of the pressure of the energy storage container and the pressure of the working container, which significantly reduces the demand for large-volume high-pressure pressure vessels in the working container of the energy storage system.

[0075] c) This invention uses multiple containers with different pressures and volumes to store and release energy during large pressure changes, which significantly reduces the container cost in energy storage and power generation and improves the technical and economic efficiency of the system.

[0076] d) The hydraulic compressed air energy storage system with pressure grading and heat replenishment of the present invention uses water as the working medium and pumps / turbines as the energy conversion equipment. It can operate with high efficiency in both high-pressure and low-pressure systems, and solves the problem that pressure changes seriously affect the system's circulation efficiency.

[0077] e) By employing forced heat exchange technologies such as atomized spraying during the compression process, this invention achieves an effect where the air temperature remains approximately constant during the energy storage process, thus solving the problems of excessive temperature rise and low energy storage efficiency in compressed air energy storage.

[0078] f) During the expansion process of the present invention, external waste heat resources are used to supplement the heat of the steam-water mixing container and the high-pressure gas storage container, thereby realizing the utilization of low-grade waste heat resources.

[0079] g) The energy storage medium of this invention is air, and the working medium is water, both of which are clean and pollution-free working fluids, thus realizing green and clean energy storage.

[0080] h) This invention contains no flammable or explosive substances at room temperature, thus fundamentally solving the safety operation problem of energy storage systems that are prone to fire and explosion.

[0081] i) This invention can not only cooperate with thermal power units for thermal power-storage frequency regulation operation, but also undertake high-frequency automatic power generation control and regulation of thermal power units.

[0082] j) The working medium of this invention is water, which is incompressible. It has the advantages of fast start-up and shutdown of water pumps and turbines and short switching time. The energy storage system has the advantage of rapid switching between energy storage and power generation conditions.

[0083] The above embodiments are merely one of the implementation methods for achieving the technical solution of the present invention. The scope of protection claimed by the present invention is not limited to this embodiment, but also includes any variations, substitutions and other implementation methods that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention.

Claims

1. A pressure staged belt reheat hydro compressed air energy storage system characterized by, The system comprises a heat supplement unit, a plurality of high-pressure gas storage containers (1), a plurality of connected steam-water mixed containers (2), and an energy conversion unit for supplementing the steam-water mixed containers (2) with liquid and generating electricity. The gas outlets of the high-pressure gas storage containers (1) are connected to the steam-water mixed containers (2) respectively. The water inlets and outlets of the steam-water mixed containers (2) are connected to the energy conversion unit respectively. The heat supplement unit is connected to the high-pressure gas storage containers (1) and the steam-water mixed containers (2) respectively, and is used for supplementing the high-pressure gas storage containers (1) and the steam-water mixed containers (2) with heat. The input port of the heat supplement unit is connected to an external heat source. The high-pressure gas storage containers (1) are connected in sequence through valves. The high-pressure gas storage containers (1) are connected to the output ports of the heat supplement unit and the steam-water mixed containers (2) respectively. The high-pressure gas storage containers (1) are of different pressure levels. The steam-water mixed containers (2) are of different pressure levels. The heat supplement unit is a heat exchanger (6), and the first heat supplement port of the heat exchanger (6) is connected to the high-pressure gas storage containers (1), and the second heat supplement port is connected to the steam-water mixed containers (2) respectively.

2. A pressure staged belt reheat hydro compressed air energy storage system according to claim 1, wherein, The gas outlets of the high-pressure gas storage containers (1) are connected to the input port of the heat exchanger (6).

3. A pressure staged belt reheat hydro compressed air energy storage system according to claim 1, wherein, The energy conversion unit comprises a water turbine (3) and a water pump (4), the water turbine (3) is connected to the water outlets of the steam-water mixed containers (2), the water pump (4) is connected to the water inlets of the steam-water mixed containers (2), and the water turbine (3) and the water pump (4) are connected to a water storage pool (5) respectively.

4. A method of operating a pressure staged belt reheat hydro-compressed air energy storage system, characterized by, The energy conversion unit is a water pump water turbine, the water inlets and outlets of the steam-water mixed containers (2) are the same, one end of the water pump water turbine is connected to the steam-water mixed containers (2), and the other end is connected to the water storage pool (5). The system according to any one of claims 1-3, comprising: In the electricity generation stage, the high-pressure gas storage containers (1) supply air to the steam-water mixed containers (2), the air drives the water in the steam-water mixed containers (2) to work after expansion, and drives the energy conversion unit to generate electricity; in the electricity generation process, the heat supplement unit supplements the high-pressure gas storage containers (1) and the steam-water mixed containers (2) with heat respectively; 5. The method of operating a pressure staged belt reheat hydro-compressed air energy storage system of claim 4, wherein, In the energy storage stage, the energy conversion unit supplements the steam-water mixed containers (2) with liquid, atomizes and sprays to reduce the temperature of the compressed air, until the steam-water mixed containers (2) and the high-pressure gas storage containers (1) reach the corresponding preset pressure values. When the gas outlets of the high-pressure gas storage containers (1) are connected to the gas source input ports of the heat supplement unit, the high-pressure gas storage containers (1) input air to the heat supplement unit for heat exchange.

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