A high-density fluid pressurized gas power generation system and method

Abstract

The application discloses a U-shaped tube type high-density fluid pressure gas power generation system and method, relates to the technical field of novel energy storage and power generation, and comprises a compressor, a gas-liquid heat exchanger one, a heat storage tank, a gas-liquid heat exchanger two, a low-position U-shaped liquid storage and gas storage warehouse, a high-position liquid storage warehouse and an expander. The pressure gas power generation system uses air as a working medium to replace traditional water of pumped storage, and the air and the high-density fluid flow in independent pipelines, so that clean air can be kept in the compressor and the expander and other equipment to work; blade corrosion and abrasion caused by the high-density fluid solution directly driving a water pump or a water turbine to work are avoided, and the service life of the equipment is prolonged; only high-strength materials capable of preventing corrosion and abrasion need to be used in the high-density fluid pipeline, so that the equipment investment cost of the whole system is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of new energy storage and power generation technology, in particular to a U-shaped tube type high-density fluid pressure gas power generation system and method. BACKGROUND

[0002] Pumped storage technology is a common way of electrical energy storage, which mainly uses excess electricity during low demand periods to pump water from a lower reservoir to a higher reservoir, and releases water flow during peak demand periods to drive a water turbine to generate electricity, thereby adjusting the balance between power supply and demand. This technology has strong flexibility, especially suitable for addressing the instability and intermittency of renewable energy sources such as wind and solar energy, and is a very clean form of energy.

[0003] However, pumped storage technology has some obvious site selection and engineering construction problems in practical application. First, site selection is difficult. The core principle of pumped storage power station is to realize gravitational potential energy conversion through high difference, so sufficient vertical difference must be considered when selecting a site, which usually needs to be between 300 meters and 500 meters. Large height difference helps to store more energy. With a smaller height difference, the water storage capacity of the reservoir is correspondingly smaller, making it difficult to meet the demand for large-scale power regulation. A low height difference will reduce the energy efficiency of pumped storage, resulting in increased costs, so site selection requires specific mountain or valley terrain.

[0004] Second, the problem of water quantity demand. Pumped storage power stations often require the construction of large-capacity reservoirs. Because the power generation working fluid of pumped storage power stations is water, if a certain scale of power generation is required, a large water storage capacity must be provided. For example, a 100 MW pumped storage power station requires 2 million to 3 million cubic meters of water storage capacity. This not only requires sufficient water sources (2 million to 3 million cubic meters), but also requires the construction of two reservoirs (upper and lower reservoirs) with a volume of 2 million to 3 million cubic meters.

[0005] In summary, the 300-500m height difference, the super-large scale of the upper and lower reservoirs and the construction of the tunnel involve a large amount of civil engineering, mechanical and electrical installation and system integration work, and these projects often require the use of heavy machinery and professional technical personnel, with a long construction period. Therefore, the construction of pumped storage power stations often requires a large investment cost and a construction period of 7-10 years. At present, these problems are still the key problems that restrict the large-scale promotion and application of pumped storage power stations, and need to be improved. SUMMARY

[0006] The application aims to provide a U-shaped tube type high-density fluid pressure gas power generation system and method, which not only solves the site selection and construction problems of large height difference and large water storage volume of traditional pumped storage, greatly reduces the engineering quantity and investment, shortens the construction period, and provides an efficient and economical heat storage and power generation system and method.

[0007] To achieve the above-mentioned purpose, the application provides the following scheme: the application provides a U-shaped tube type high-density fluid pressure gas power generation system, which comprises a compressor, a gas-liquid heat exchanger I, a heat storage tank, a gas-liquid heat exchanger II, a low-position U-shaped liquid storage and gas storage reservoir, a high-position liquid storage reservoir and an expander.

[0008] The gas inlet pipe of the compressor, the compressor, the gas outlet pipe of the compressor, the gas-liquid heat exchanger I and the gas outlet pipe of the gas-liquid heat exchanger I are sequentially connected, the gas-liquid heat exchanger I is connected with the gas-liquid heat exchanger I liquid inlet pipe and the gas-liquid heat exchanger I liquid outlet pipe respectively, the gas-liquid heat exchanger I liquid outlet pipe is connected with the heat storage tank, the three-way valve I is connected with the gas-liquid heat exchanger I gas outlet pipe, the gas guide pipe and the gas-liquid heat exchanger II gas inlet pipe respectively, the three-way valve II is connected with the gas-liquid heat exchanger I liquid inlet pipe, the liquid guide pipe and the gas-liquid heat exchanger II liquid outlet pipe respectively, the liquid guide pipe is connected with the low-position U-shaped liquid storage and gas storage reservoir, the low-position U-shaped liquid storage and gas storage reservoir is filled with high-density fluid, and the low-position U-shaped liquid storage and gas storage reservoir is connected with the high-position liquid storage reservoir through the upper and lower reservoir drainage pipes; the gas-liquid heat exchanger II gas inlet pipe is connected with the gas-liquid heat exchanger II and the gas-liquid heat exchanger II gas outlet pipe; the gas-liquid heat exchanger II is connected with the gas-liquid heat exchanger II liquid inlet pipe and the gas-liquid heat exchanger II liquid outlet pipe respectively; the other end of the gas-liquid heat exchanger II liquid inlet pipe is connected with the heat storage tank; the gas-liquid heat exchanger II gas outlet pipe, the expander and the expander gas outlet pipe are sequentially connected.

[0009] In an embodiment, the high-density fluid is a fluid with a density of more than 1 times the density of water; the smaller the height difference between the low-position U-shaped liquid storage and gas storage reservoir and the high-position liquid storage reservoir, the higher the density of the selected high-density fluid.

[0010] In an embodiment, the height of the high-density fluid remains unchanged during the entire operation of the system; the boundary between the high-density fluid and the air always moves back and forth at the bottom end of the low-position U-shaped liquid storage and gas storage reservoir.

[0011] In an embodiment, the low-position U-shaped liquid storage and gas storage reservoir is in a state of coexistence of high-density fluid and air; the pressure of the air in the low-position U-shaped liquid storage and gas storage reservoir is the difference in gravitational potential energy of the high-density fluid between the high-position liquid storage reservoir and the low-position U-shaped liquid storage and gas storage reservoir; the air pressure in the low-position U-shaped liquid storage and gas storage reservoir is the design pressure of the pressure gas power generation system, which remains unchanged during the entire energy storage and power generation process.

[0012] In an embodiment, the end of the low U-shaped liquid storage and gas storage reservoir connected with the upper and lower reservoir drainage pipe is filled with high-density fluid, and the end of the low U-shaped liquid storage and gas storage reservoir connected with the upper and lower reservoir drainage pipe always has high-density fluid remaining during the entire operation of the energy storage and power generation system.

[0013] In an embodiment, the end of the low U-shaped liquid storage and gas storage reservoir connected with the upper and lower reservoir drainage pipe is filled with high-density fluid, and the end of the low U-shaped liquid storage and gas storage reservoir connected with the upper and lower reservoir drainage pipe always has high-density fluid remaining during the entire operation of the energy storage and power generation system.

[0014] In an embodiment, the outside of the heat storage tank is wrapped with thermal insulation material, and the inside of the heat storage tank is filled with high-temperature high-density fluid.

[0015] In an embodiment, in the entire compressed air power generation system, a high-strength material coated with corrosion and wear resistance is used in the pipeline through which the high-density fluid flows.

[0016] The application also provides a compressed air energy storage working method of a U-shaped tube type high-density fluid compressed air power generation system, which is applied to the U-shaped tube type high-density fluid compressed air power generation system and includes the following steps:

[0017] During the low electricity consumption period, the excess electricity of the power grid or the abandoned electricity of the new energy system drives the compressor to start rotating, and the ambient air at room temperature is introduced into the compressor through the compressor air inlet pipe, and the air is compressed into high-temperature and high-pressure air in the compressor and introduced into the gas-liquid heat exchanger one through the compressor air outlet pipe, at this time, the three-way valve two is opened.

[0018] The room temperature high-density fluid in the low U-shaped liquid storage and gas storage reservoir flows into the gas-liquid heat exchanger one through the liquid guide pipe, the three-way valve two and the gas-liquid heat exchanger one liquid inlet pipe, and the high-temperature and high-pressure air in the gas-liquid heat exchanger one releases heat to the room temperature high-density fluid, and becomes room temperature and high-pressure air and flows out from the gas-liquid heat exchanger one air outlet pipe, at this time, the three-way valve one is opened, and the room temperature and high-pressure air flows into the low U-shaped liquid storage and gas storage reservoir through the three-way valve one and the gas guide pipe.

[0019] During the compressed air energy storage working state, as the high-pressure air in the low U-shaped liquid storage and gas storage reservoir gradually increases, the air volume increases, the high-density fluid flows out, and the high-pressure air gradually occupies the volume at the bottom of the low U-shaped liquid storage and gas storage reservoir; a part of the high-density fluid flows into the high liquid storage reservoir along the upper and lower reservoir drainage pipe, and another part of the high-density fluid flows out through the liquid guide pipe and flows into the gas-liquid heat exchanger one for heat exchange; the high-temperature and high-density fluid after heat absorption in the gas-liquid heat exchanger one flows into the heat storage tank through the gas-liquid heat exchanger one liquid outlet pipe for storage; when reaching the gas-liquid demarcation position at the bottom of the end of the low U-shaped liquid storage and gas storage reservoir connected with the upper and lower reservoir drainage pipe, the energy storage process is completed, at this time, the three-way valve one and the three-way valve two are closed.

[0020] The application also provides a gravity potential energy conversion power generation working method of a U-shaped tube type high-density fluid pressure gas power generation system, which is applied to the high-density fluid pressure gas power generation system and includes the following steps:

[0021] During the power consumption peak period, the three-way valve one is opened, the normal-temperature high-pressure air in the low-position U-shaped liquid storage gas storage is led into the gas-liquid heat exchanger two through the gas guide pipe and the three-way valve one, at this time, the high-temperature high-density fluid in the heat storage tank is led into the gas-liquid heat exchanger two through the liquid inlet pipe, the normal-temperature high-pressure air absorbs the heat of the high-temperature high-density fluid in the gas-liquid heat exchanger two, becomes high-temperature high-pressure air, and is led out from the gas outlet pipe of the gas-liquid heat exchanger two and into the expander to do work and generate power, becomes normal-temperature low-pressure air, and is led out from the gas outlet pipe of the expander and discharged into the atmosphere;

[0022] At the same time, the three-way valve two is opened, the normal-temperature high-density fluid after heat release in the gas-liquid heat exchanger two is led into the low-position U-shaped liquid storage gas storage through the liquid outlet pipe, the three-way valve two and the liquid guide pipe;

[0023] Under the gravity potential energy conversion power generation working state, as the high-pressure air in the low-position U-shaped liquid storage gas storage is gradually discharged, the air volume is reduced, the constant gravity potential energy difference between the high-position liquid storage and the low-position U-shaped liquid storage gas storage drives the high-density fluid to flow into the low-position U-shaped liquid storage gas storage along the upper and lower storage guide pipes, and the high-density fluid led in through the liquid guide pipe is combined to supplement the reduced air volume at the bottom of the low-position U-shaped liquid storage gas storage; when reaching the bottom gas-liquid demarcation position of the end connected with the gas guide pipe of the low-position U-shaped liquid storage gas storage, the power generation process is ended, at this time, the three-way valve one and the three-way valve two are closed.

[0024] The application has the following beneficial technical effects compared with the prior art:

[0025] The U-shaped tube type high-density fluid pressure gas power generation system and method of the application include a compressor, a gas-liquid heat exchanger one, a heat storage tank, a gas-liquid heat exchanger two, a low-position U-shaped liquid storage gas storage, a high-position liquid storage and an expander. The air is used as the working medium to replace the traditional water in the pumped storage, the air and the high-density fluid flow in the independent pipelines, the clean air can be kept in the compressor and the expander, the blade corrosion and wear caused by the high-density fluid solution directly driving the water pump or the water turbine are avoided, the service life of the equipment is enhanced, the high-strength material resistant to corrosion and wear is only needed in the high-density fluid pipeline, and the equipment investment cost of the whole system is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed in the embodiments. Obviously, the drawings described below only illustrate some of the embodiments of the present application, and are not all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the scope of protection of the present application.

[0027] Figure 1 Figure 1 is a schematic diagram of a high-density fluid pressure gas power generation system in a U-shaped tube type;

[0028] Figure 2 Figure 2 is a schematic diagram of a high-density fluid pressure gas power generation system in a U-shaped tube type in a pressure energy storage working state;

[0029] Figure 3 Figure 3 is a schematic diagram of the flow state of high-density fluid and air in a low-position U-shaped liquid storage gas reservoir in a pressure energy storage working state of the system;

[0030] Figure 4 Figure 4 is a schematic diagram of a high-density fluid pressure gas power generation system in a U-shaped tube type in a gravity potential energy conversion power generation working state;

[0031] Figure 5 Figure 5 is a schematic diagram of the flow state of high-density fluid and air in a low-position U-shaped liquid storage gas reservoir in a gravity potential energy conversion power generation working state of the system;

[0032] In the drawings, 1 is a compressor inlet pipe, 2 is a compressor, 3 is a compressor outlet pipe, 4 is a gas-liquid heat exchanger one, 5 is a gas-liquid heat exchanger one outlet pipe, 6 is a gas-liquid heat exchanger one inlet pipe, 7 is a gas-liquid heat exchanger one outlet pipe, 8 is a heat storage tank, 9 is a three-way valve one, 10 is a gas guide pipe, 11 is a gas-liquid heat exchanger two inlet pipe, 12 is a three-way valve two, 13 is a liquid guide pipe, 14 is a low-position U-shaped liquid storage gas reservoir, 15 is high-density fluid, 16 is an up-down reservoir flow guide pipe, 17 is a high-position liquid storage reservoir, 18 is a gas-liquid heat exchanger two, 19 is a gas-liquid heat exchanger two outlet pipe, 20 is a gas-liquid heat exchanger two inlet pipe, 21 is a gas-liquid heat exchanger two outlet pipe, 22 is an expander, and 23 is an expander outlet pipe. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, and are not all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the scope of protection of the present application.

[0034] The application aims to provide a U-shaped tube type high-density fluid air compression power generation system and method. The high-density fluid has a larger gravity potential energy than water, so that the height difference between the upper reservoir and the lower reservoir of a conventional pumped storage power station can be reduced by several times, the engineering quantity is reduced, and the site applicability is improved; the high-density fluid and air are naturally divided into two areas by the U-shaped tube type underground reservoir, so that the gas-liquid mixing disturbance and the liquid flowing out with the gas of the conventional gas-liquid coexistence container are avoided; the compressible characteristics of air are used to drive the expander to work and generate power, so that the volume of the reservoir required by the conventional pumped storage power station is greatly reduced, the volume of the liquid required is greatly reduced, and the power generation efficiency close to the pumped storage system can be achieved; the waste heat of the compressed gas is recovered by the high-density fluid, the waste heat is reused to generate power, the system energy loss is reduced, and the high-density fluid resource and heat energy are reused. The application not only solves the site construction problems such as large height difference and large reservoir volume of the traditional pumped storage, greatly reduces the engineering quantity and investment, shortens the construction period, but also provides an efficient and economical heat storage and power generation system and method.

[0035] In order to make the above-mentioned objects, features and advantages of the application more obvious and easy to understand, the application will be further described in detail below with reference to the drawings and specific embodiments.

[0036] As shown in Figures 1-5 The application provides a U-shaped tube type high-density fluid air compression power generation system, which comprises a compressor air inlet pipe 1, a compressor 2, a compressor air outlet pipe 3, a gas-liquid heat exchanger I 4, a gas-liquid heat exchanger I air outlet pipe 5, a gas-liquid heat exchanger I liquid inlet pipe 6, a gas-liquid heat exchanger I liquid outlet pipe 7, a heat storage tank 8, a three-way valve I 9, a gas guide pipe 10, a gas-liquid heat exchanger II air inlet pipe 11, a three-way valve II 12, a liquid guide pipe 13, a low-position U-shaped liquid and gas storage reservoir 14, high-density fluid 15, upper and lower reservoir drainage pipes 16, a high-position liquid storage reservoir 17, a gas-liquid heat exchanger II 18, a gas-liquid heat exchanger II air outlet pipe 19, a gas-liquid heat exchanger II liquid inlet pipe 20, a gas-liquid heat exchanger II liquid outlet pipe 21, an expander 22, and an expander air outlet pipe 23.

[0037] The compressor inlet pipe 1, compressor 2, compressor outlet pipe 3, gas-liquid heat exchanger 4, and gas-liquid heat exchanger outlet pipe 5 are connected in sequence. In addition, gas-liquid heat exchanger 4 is connected to gas-liquid heat exchanger inlet pipe 6 and gas-liquid heat exchanger outlet pipe 7 respectively. Gas-liquid heat exchanger outlet pipe 7 is connected to heat storage tank 8. Three-way valve 9 is connected to gas-liquid heat exchanger outlet pipe 5, gas guide pipe 10, and gas-liquid heat exchanger inlet pipe 11 respectively. Three-way valve 12 is connected to gas-liquid heat exchanger inlet pipe 6, gas guide pipe 13, and gas-liquid heat exchanger outlet pipe 21 respectively. Gas guide pipe 13 is connected to low-level U-shaped liquid and gas storage tank 14. The low-level U-shaped liquid and gas storage tank 14 is filled with high-density fluid 15. The low-level U-shaped liquid and gas storage tank 14 is connected to high-level liquid storage tank 17 through upper and lower tank drainage pipes 16. The second inlet pipe 11 of the gas-liquid heat exchanger is connected to the second gas-liquid heat exchanger 18 and the second gas-liquid heat exchanger outlet pipe 19. Furthermore, the second gas-liquid heat exchanger 18 is connected to the second gas-liquid heat exchanger liquid inlet pipe 20 and the second gas-liquid heat exchanger liquid outlet pipe 21, respectively. The other end of the second gas-liquid heat exchanger liquid inlet pipe 20 is connected to the heat storage tank 8. The second gas-liquid heat exchanger outlet pipe 19, the expander 22, and the expander outlet pipe 23 are connected sequentially.

[0038] A U-tube type high-density fluid compressed gas power generation system includes a compressed gas energy storage working state and a gravitational potential energy conversion power generation working state. The processes of these two working states are as follows:

[0039] Compressed gas energy storage working process:

[0040] like Figure 2 As shown, during periods of low electricity demand, excess electricity from the power grid or curtailed wind and solar power from renewable energy systems drives compressor 2 to start rotating. Room temperature air from the environment is introduced into compressor 2 through compressor inlet pipe 1. The air is compressed into high-temperature, high-pressure air within compressor 2 and introduced into gas-liquid heat exchanger 4 through compressor outlet pipe 3. At this time, three-way valve 12 is opened. Room temperature, high-density fluid 15 in the low-level U-shaped liquid-gas storage tank 14 flows into gas-liquid heat exchanger 4 through liquid guide pipe 13, three-way valve 12, and gas-liquid heat exchanger inlet pipe 6. The high-temperature, high-pressure air releases heat to the room temperature, high-density fluid 15 within gas-liquid heat exchanger 4, becoming room temperature, high-pressure air, which then flows out through gas-liquid heat exchanger outlet pipe 5. At this time, three-way valve 9 is opened, and the room temperature, high-pressure air flows into the low-level U-shaped liquid-gas storage tank 14 through three-way valve 9 and liquid guide pipe 10. Figure 3As shown, in the compressed air energy storage state, with the gradual increase of high-pressure air in the low U-shaped liquid storage and air reservoir 14, the air volume increases, pushing the high-density fluid 15 to flow out, and the high-pressure air gradually occupies the volume at the bottom of the low U-shaped liquid storage and air reservoir 14. Part of the high-density fluid 15 flows into the high liquid reservoir 17 along the upper and lower reservoir flow guide pipe 16, and part of the high-density fluid 15 flows out through the liquid guide pipe 13 and flows into the gas-liquid heat exchanger 1 4 for heat exchange. The high-temperature high-density fluid 15 after heat absorption in the gas-liquid heat exchanger 1 4 flows into the heat storage tank 8 through the gas-liquid heat exchanger 1 outflow pipe 7 for storage. When the gas-liquid separation position as shown is reached, the energy storage process is completed, and the three-way valve 1 9 and the three-way valve 1 2 are closed at this time. Figure 3 As shown, in the compressed air energy storage state, with the gradual increase of high-pressure air in the low U-shaped liquid storage and air reservoir 14, the air volume increases, pushing the high-density fluid 15 to flow out, and the high-pressure air gradually occupies the volume at the bottom of the low U-shaped liquid storage and air reservoir 14. Part of the high-density fluid 15 flows into the high liquid reservoir 17 along the upper and lower reservoir flow guide pipe 16, and part of the high-density fluid 15 flows out through the liquid guide pipe 13 and flows into the gas-liquid heat exchanger 1 4 for heat exchange. The high-temperature high-density fluid 15 after heat absorption in the gas-liquid heat exchanger 1 4 flows into the heat storage tank 8 through the gas-liquid heat exchanger 1 outflow pipe 7 for storage. When the gas-liquid separation position as shown is reached, the energy storage process is completed, and the three-way valve 1 9 and the three-way valve 1 2 are closed at this time.

[0041] The process of gravity potential energy conversion and power generation working state:

[0042] As shown, in the compressed air energy storage state, with the gradual increase of high-pressure air in the low U-shaped liquid storage and air reservoir 14, the air volume increases, pushing the high-density fluid 15 to flow out, and the high-pressure air gradually occupies the volume at the bottom of the low U-shaped liquid storage and air reservoir 14. Part of the high-density fluid 15 flows into the high liquid reservoir 17 along the upper and lower reservoir flow guide pipe 16, and part of the high-density fluid 15 flows out through the liquid guide pipe 13 and flows into the gas-liquid heat exchanger 1 4 for heat exchange. The high-temperature high-density fluid 15 after heat absorption in the gas-liquid heat exchanger 1 4 flows into the heat storage tank 8 through the gas-liquid heat exchanger 1 outflow pipe 7 for storage. When the gas-liquid separation position as shown is reached, the energy storage process is completed, and the three-way valve 1 9 and the three-way valve 1 2 are closed at this time. Figure 4 As shown, in the compressed air energy storage state, with the gradual increase of high-pressure air in the low U-shaped liquid storage and air reservoir 14, the air volume increases, pushing the high-density fluid 15 to flow out, and the high-pressure air gradually occupies the volume at the bottom of the low U-shaped liquid storage and air reservoir 14. Part of the high-density fluid 15 flows into the high liquid reservoir 17 along the upper and lower reservoir flow guide pipe 16, and part of the high-density fluid 15 flows out through the liquid guide pipe 13 and flows into the gas-liquid heat exchanger 1 4 for heat exchange. The high-temperature high-density fluid 15 after heat absorption in the gas-liquid heat exchanger 1 4 flows into the heat storage tank 8 through the gas-liquid heat exchanger 1 outflow pipe 7 for storage. When the gas-liquid separation position as shown is reached, the energy storage process is completed, and the three-way valve 1 9 and the three-way valve 1 2 are closed at this time. Figure 5 As shown, in the compressed air energy storage state, with the gradual increase of high-pressure air in the low U-shaped liquid storage and air reservoir 14, the air volume increases, pushing the high-density fluid 15 to flow out, and the high-pressure air gradually occupies the volume at the bottom of the low U-shaped liquid storage and air reservoir 14. Part of the high-density fluid 15 flows into the high liquid reservoir 17 along the upper and lower reservoir flow guide pipe 16, and part of the high-density fluid 15 flows out through the liquid guide pipe 13 and flows into the gas-liquid heat exchanger 1 4 for heat exchange. The high-temperature high-density fluid 15 after heat absorption in the gas-liquid heat exchanger 1 4 flows into the heat storage tank 8 through the gas-liquid heat exchanger 1 outflow pipe 7 for storage. When the gas-liquid separation position as shown is reached, the energy storage process is completed, and the three-way valve 1 9 and the three-way valve 1 2 are closed at this time. Figure 5 As shown, in the compressed air energy storage state, with the gradual increase of high-pressure air in the low U-shaped liquid storage and air reservoir 14, the air volume increases, pushing the high-density fluid 15 to flow out, and the high-pressure air gradually occupies the volume at the bottom of the low U-shaped liquid storage and air reservoir 14. Part of the high-density fluid 15 flows into the high liquid reservoir 17 along the upper and lower reservoir flow guide pipe 16, and part of the high-density fluid 15 flows out through the liquid guide pipe 13 and flows into the gas-liquid heat exchanger 1 4 for heat exchange. The high-temperature high-density fluid 15 after heat absorption in the gas-liquid heat exchanger 1 4 flows into the heat storage tank 8 through the gas-liquid heat exchanger 1 outflow pipe 7 for storage. When the gas-liquid separation position as shown is reached, the energy storage process is completed, and the three-way valve 1 9 and the three-way valve 1 2 are closed at this time.

[0043] In one embodiment, the high-density fluid used in the present application is a fluid with a density of more than 1 times the density of water, and is safe, non-toxic, stable in nature, and weakly corrosive. Such high-density fluids include, but are not limited to, glycerol, ethylene glycol, high-concentration sugar alcohol solutions, high-concentration salt solutions composed of binary or ternary mixtures of potassium nitrate, sodium nitrite, sodium nitrate, and molten salt materials. The type of high-density fluid can be selected flexibly according to the height difference between the upper and lower reservoirs at the project construction site. The smaller the height difference between the upper and lower reservoirs, the higher the density of the selected high-density fluid, i.e., a relatively large gravitational potential energy can be achieved under small height differences. As shown in FIGS. 1, 2, and 3, the height of the high-density fluid remains unchanged throughout the entire operation of the system. The interface between the high-density fluid and the air always moves back and forth at the bottom end of the low U-shaped liquid storage and gas storage reservoir, which can maximize the maintenance of the constant gravitational potential energy of the system and the constant air pressure. Figure 4 and Figure 5 As shown in FIGS. 1, 2, and 3, the height of the high-density fluid remains unchanged throughout the entire operation of the system. The interface between the high-density fluid and the air always moves back and forth at the bottom end of the low U-shaped liquid storage and gas storage reservoir, which can maximize the maintenance of the constant gravitational potential energy of the system and the constant air pressure.

[0044] In one embodiment, the low U-shaped liquid storage and gas storage reservoir designed in the present application is filled with high-density fluid while always maintaining a portion of air. The pressure of the air is the difference in gravitational potential energy between the high-density fluid in the high liquid storage reservoir and the low U-shaped liquid storage and gas storage reservoir. This pressure is the design pressure of the compressed air power generation system, and remains unchanged throughout the energy storage and power generation process. The end of the low U-shaped liquid storage and gas storage reservoir connected to the upper and lower reservoirs is filled with high-density fluid, and during the entire operation of the energy storage and power generation system, high-density fluid always remains at one end of the low U-shaped liquid storage and gas storage reservoir, thereby preventing air from flowing out through the upper and lower reservoirs. The end of the low U-shaped liquid storage and gas storage reservoir connected to the air guide pipe is filled with high-density fluid, and during the entire operation of the energy storage and power generation system, air always remains at one end of the low U-shaped liquid storage and gas storage reservoir, thereby preventing high-density fluid from flowing out through the air guide pipe.

[0045] In one embodiment, the heat storage tank designed in the present application is wrapped with thermal insulation materials, including but not limited to rock wool, glass wool, polystyrene foam, and other materials. The heat storage tank is filled with high-temperature high-density fluid. These high-density fluids are high-temperature high-density fluids obtained by heat exchange between the high-temperature compressed air after being compressed by the compressor in the gas-liquid heat exchanger 1 and the high-temperature compressed air, and are stored in the heat storage tank. During power generation, these high-temperature high-density fluids heat the air in the gas-liquid heat exchanger 2, and the heat-absorbed high-temperature air does work to generate electricity through the expander.

[0046] The compressed air power generation system designed by the application uses air as working medium to replace the traditional water of pumped storage, and the air and high-density fluid flow in independent pipelines respectively, so that clean air can be kept in the compressor and expander to work. The corrosion and wear of the blade caused by the high-density fluid solution directly driving the water pump or water turbine to work are avoided, and the service life of the equipment is enhanced. Only high-strength materials resistant to corrosion and wear are needed in the high-density fluid pipeline, reducing the equipment investment cost of the whole system.

[0047] It should be noted that, for those skilled in the art, it is obvious that the present application is not limited to the details of the above exemplary embodiments, and the present application can be implemented in other specific forms without departing from the spirit or essential characteristics of the present application. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting, and the scope of the present application is defined by the appended claims rather than the above description, and therefore all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present application, and any reference signs in the claims should not be regarded as limiting the claims.

[0048] In the present application, specific examples are applied to illustrate the principles and implementation modes of the present application. The above embodiment is only used to help understand the method of the present application and its core idea; at the same time, for those skilled in the art, according to the idea of the present application, the specific implementation mode and application range will be changed. In conclusion, the content of the specification should not be understood as a limitation of the present application.

Claims

1. A U-tube high-density fluid pressurized gas power generation system characterized by: The system comprises a compressor, a gas-liquid heat exchanger I, a heat storage tank, a gas-liquid heat exchanger II, a low-position U-shaped liquid and gas storage, a high-position liquid storage and an expander. The air inlet pipe of the compressor, the compressor, the air outlet pipe of the compressor, the gas-liquid heat exchanger I, the air outlet pipe of the gas-liquid heat exchanger I are sequentially connected, the gas-liquid heat exchanger I is connected with the liquid inlet pipe of the gas-liquid heat exchanger I and the liquid outlet pipe of the gas-liquid heat exchanger I, the liquid outlet pipe of the gas-liquid heat exchanger I is connected with the heat storage tank, the three-way valve I is connected with the air outlet pipe of the gas-liquid heat exchanger I, the gas guide pipe and the gas inlet pipe of the gas-liquid heat exchanger II, the gas guide pipe is connected with the low-position U-shaped liquid and gas storage, the three-way valve II is connected with the liquid inlet pipe of the gas-liquid heat exchanger I, the liquid guide pipe and the liquid outlet pipe of the gas-liquid heat exchanger II, the liquid guide pipe is connected with the low-position U-shaped liquid and gas storage, the low-position U-shaped liquid and gas storage is filled with high-density fluid, the low-position U-shaped liquid and gas storage is connected with the high-position liquid storage through the upper and lower tank drainage pipes, the gas inlet pipe of the gas-liquid heat exchanger II is connected with the gas-liquid heat exchanger II and the gas outlet pipe of the gas-liquid heat exchanger II, the gas-liquid heat exchanger II is connected with the liquid inlet pipe of the gas-liquid heat exchanger II and the liquid outlet pipe of the gas-liquid heat exchanger II, the other end of the liquid inlet pipe of the gas-liquid heat exchanger II is connected with the heat storage tank, the gas outlet pipe of the gas-liquid heat exchanger II, the expander and the air outlet pipe of the expander are sequentially connected.

2. The U-tube type high-density fluid pressure gas power generation system according to claim 1, characterized by: The high-density fluid is a fluid with a density of more than 1 times the density of water, and the smaller the height difference between the low-position U-shaped liquid and gas storage and the high-position liquid storage, the higher the density of the selected high-density fluid.

3. The U-tube high-density fluid pressurized gas power generation system according to claim 2, characterized by: During the entire operation of the system, the height of the high-density fluid remains unchanged, and the boundary between the high-density fluid and air always moves back and forth at the bottom end of the low-position U-shaped liquid and gas storage.

4. The U-tube type high-density fluid pressure gas power generation system according to claim 1, characterized by: The low-position U-shaped liquid and gas storage is in a state of coexistence of high-density fluid and air, the pressure of the air in the low-position U-shaped liquid and gas storage is the difference in gravitational potential energy of the high-density fluid between the high-position liquid storage and the low-position U-shaped liquid and gas storage, and the air pressure in the low-position U-shaped liquid and gas storage is the design pressure of the compressed air power generation system and remains unchanged during the entire energy storage and power generation process.

5. The U-tube high-density fluid pressurized gas power generation system according to claim 1, characterized by: The end of the low-position U-shaped liquid and gas storage connected with the upper and lower tank drainage pipes is filled with high-density fluid, and the end of the low-position U-shaped liquid and gas storage connected with the upper and lower tank drainage pipes always retains high-density fluid during the entire operation of the energy storage and power generation system.

6. The U-tube high-density fluid pressurized gas power generation system according to claim 1, characterized by: The end of the low-position U-shaped liquid and gas storage connected with the gas guide pipe is filled with air, and the end of the low-position U-shaped liquid and gas storage connected with the gas guide pipe always retains air during the entire operation of the energy storage and power generation system.

7. The U-tube high-density fluid pressurized gas power generation system according to claim 1, characterized by: The heat storage tank is wrapped with thermal insulation material, and the inside of the heat storage tank is filled with high-density fluid.

8. The U-tube high-density fluid pressurized gas power generation system according to claim 1, characterized by: In the entire compressed air power generation system, the pipelines through which the high-density fluid flows are coated with corrosion-resistant and wear-resistant materials.

9. A method for the compression energy storage operation of a U-tube high-density fluid compressed air power generation system, applied to the U-tube high-density fluid compressed air power generation system of any one of claims 1-8, characterized in that, The system comprises the following steps: During the off-peak period of electricity consumption, the excess electricity of the power grid or the abandoned electricity of the new energy system drives the compressor to start rotating, and the ambient air at room temperature is introduced into the compressor through the air inlet pipe of the compressor. The air is compressed into high-temperature and high-pressure air in the compressor and introduced into the gas-liquid heat exchanger I through the air outlet pipe of the compressor, and the three-way valve II is opened at this time. The normal-temperature high-density fluid in the low-position U-shaped liquid and gas storage is flowed into the gas-liquid heat exchanger one through the liquid guide pipe, the three-way valve two and the gas-liquid heat exchanger one liquid inlet pipe, the high-temperature high-pressure air in the gas-liquid heat exchanger one releases heat to the normal-temperature high-density fluid, becomes the normal-temperature high-pressure air and is flowed out from the gas-liquid heat exchanger one gas outlet pipe, at this time, the three-way valve one is opened, the normal-temperature high-pressure air is flowed into the low-position U-shaped liquid and gas storage through the three-way valve one and the gas guide pipe; In the compressed air energy storage working state, with the increase of the high-pressure air in the low-position U-shaped liquid and gas storage, the air volume is increased, the high-density fluid is pushed out, the high-pressure air gradually occupies the volume at the bottom of the low-position U-shaped liquid and gas storage, a part of the high-density fluid is flowed into the high-position liquid storage through the up-and-down storage guide pipe, another part of the high-density fluid is flowed out through the liquid guide pipe and is flowed into the gas-liquid heat exchanger one to exchange heat, the high-temperature high-density fluid after absorbing heat in the gas-liquid heat exchanger one is flowed into the heat storage tank through the gas-liquid heat exchanger one liquid outlet pipe, when reaching the gas-liquid demarcation position at the bottom of the one end of the low-position U-shaped liquid and gas storage and the up-and-down storage guide pipe, the energy storage process is ended, at this time, the three-way valve one and the three-way valve two are closed.

10. A method for generating electricity by converting gravitational potential energy in a U-tube high-density fluid compressor power generation system, applied to the U-tube high-density fluid compressor power generation system according to any one of claims 1-8, characterized in that... The steps include the following steps: In the electricity peak period, the three-way valve one is opened, the normal-temperature high-pressure air in the low-position U-shaped liquid and gas storage is flowed into the gas-liquid heat exchanger two through the gas guide pipe, the three-way valve one and the gas-liquid heat exchanger two gas inlet pipe, at this time, the high-temperature high-density fluid in the heat storage tank is flowed into the gas-liquid heat exchanger two through the gas-liquid heat exchanger two liquid inlet pipe, the normal-temperature high-pressure air absorbs the heat of the high-temperature high-density fluid in the gas-liquid heat exchanger two, becomes the high-temperature high-pressure air and is flowed out from the gas-liquid heat exchanger two gas outlet pipe and is flowed into the expander to do work and generate electricity, becomes the normal-temperature low-pressure air and is flowed out from the expander gas outlet pipe and is discharged into the atmosphere; At the same time, the three-way valve two is opened, the normal-temperature high-density fluid after releasing heat in the gas-liquid heat exchanger two is flowed into the low-position U-shaped liquid and gas storage through the gas-liquid heat exchanger two liquid outlet pipe, the three-way valve two and the liquid guide pipe; In the gravity potential energy conversion and power generation working state, with the gradual discharge of the high-pressure air in the low-position U-shaped liquid and gas storage, the air volume is decreased, the constant gravity potential energy difference between the high-position liquid storage and the low-position U-shaped liquid and gas storage pushes the high-density fluid to flow into the low-position U-shaped liquid and gas storage through the up-and-down storage guide pipe, the high-density fluid flowed in through the liquid guide pipe is combined to supplement the reduced air volume at the bottom of the low-position U-shaped liquid and gas storage, when reaching the gas-liquid demarcation position at the bottom of the one end of the low-position U-shaped liquid and gas storage and the gas guide pipe, the power generation process is ended, at this time, the three-way valve one and the three-way valve two are closed.

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