Hydraulic pressure type compressed air hybrid energy storage power generation system and operation method thereof

Abstract

The invention relates to a hydraulic pressure type compressed air hybrid energy storage power generation system and an operation method thereof, and belongs to the technical field of physical energy storage. The compression and expansion mechanical module is used for compressing gas and conveying the compressed gas to the storage module; the storage module is used for receiving the gas of the compression and expansion mechanical module to store energy and then conveying the stored energy to the power generation module; and the power generation module is used for converting energy generated by the high-pressure gas stored in the air storage module into electric energy. By adopting the air storage tank to store air and water, the problem that the site selection of the pumped storage technology is limited is solved, and the site selection is relatively flexible. According to the invention, the air storage tank is adopted to supplement air, so that the amplitude of the running water head at the hydraulic machinery is reduced, and the running efficiency and stability of the hydraulic machinery are improved.

Description

Technical Field

[0001] The invention relates to a hybrid energy storage power generation system and a method thereof, and belongs to the technical field of physical energy storage. Background Art

[0002] With the continuous consumption of fossil energy, environmental pollution problems are becoming increasingly serious, and the green transformation of energy structure is imperative. In recent years, the installed capacity of wind and solar energy has continued to increase rapidly; as of June 2024, the installed capacity of wind power is 467 million kW and the installed capacity of photovoltaic power generation is 714 million kW. As the intermittent and uncertain wind and solar grid-connected capacity continues to increase rapidly, the supply and demand balance problem of the power grid has become more prominent. Therefore, the power grid urgently needs energy storage equipment to enhance its regulation and absorption capacity. Based on pumped storage and compressed air energy storage technology, scholars have proposed a pumped water compressed air hybrid energy storage technology. For example: the publication number is CN 117267035A, and the name of the invention is a constant-pressure non-supplementary-fired pumped-coupled compressed air energy storage system based on water pressure compensation. Compared with conventional pumped-storage power stations, its technical solution uses a compressed air energy storage system to squeeze water into an upstream reservoir for energy storage. When generating electricity, it can generate electricity through an expander and a turbine, but its solution is limited in site selection; the publication number is CN112134363B, and the name of the invention is an internally temperature-controlled liquid piston device for isothermal compressed air energy storage. Its technical solution compresses air to store energy by injecting water into the tank, but the air pressure amplitude in the tank in its solution does not match the head amplitude of the hydraulic machinery.

[0003] Therefore, there is an urgent need to propose a hydraulic compressed air hybrid energy storage power generation system and an operation method thereof to solve the above technical problems. Summary of the invention

[0004] In order to solve the above problems, a water-pressure type compressed air hybrid energy storage power generation system and its operation method are provided. A brief overview of the present invention is given below to provide a basic understanding of certain aspects of the present invention. It should be understood that this overview is not an exhaustive overview of the present invention. It is not intended to determine the key or important parts of the present invention, nor is it intended to limit the scope of the present invention.

[0005] The technical solution of the present invention:

[0006] A hydraulic compressed air hybrid energy storage power generation system, comprising a compression expansion mechanical module, an air storage module and a power generation module;

[0007] Compression expansion mechanical module: used to compress gas and transport the compressed gas to the air storage module;

[0008] Air storage module: used to receive gas from the compression expansion mechanical module for energy storage, and then transmit the stored energy to the power generation module;

[0009] Power generation module: converts the energy generated by the high-pressure gas stored in the air storage module into electrical energy.

[0010] Preferably: the compression-expansion mechanical module includes a piston compressor and an expander, the piston compressor includes a piston cavity and a piston, a piston that can slide up and down is arranged in the piston cavity, the piston compressor is connected to the air storage module, and the expander is connected to the power generation module.

[0011] Preferably: the air storage module includes a first air tank, a second air tank and a heat exchange device, the piston cavity outlet of the piston compressor is connected to the inlet of the first air tank, the outlet of the first air tank is connected to the inlet and outlet of the second air tank, the outlet of the first air tank and the inlet and outlet of the second air tank are both connected to the power generation module, and the first air tank and the second air tank are connected to the heat exchange device.

[0012] The heat exchange device is an enhanced heat exchange device, which includes a water tank, a first lower water pump, a first upper water pump, a second lower water pump, a second upper water pump, a first lower spiral pipe, a first upper spiral pipe, a second lower spiral pipe and a second upper spiral pipe. The first upper spiral pipe and the first lower spiral pipe arranged up and down are installed inside the first gas storage tank. One end of the first upper spiral pipe is connected to the output end of the first upper water pump, and the other end of the first upper spiral pipe is connected to the upper part of the water tank. The input end of the first upper water pump is connected to the upper part of the water tank through a long pipe, and one end of the first lower spiral pipe is connected to the first The output end of the lower water pump is connected, the other end of the first lower spiral pipe is connected to the lower part of the water tank, the second upper spiral pipe and the second lower spiral pipe arranged up and down are installed inside the second air storage tank, one end of the second upper spiral pipe is connected to the output end of the second upper water pump, the other end of the second upper spiral pipe is connected to the upper part of the water tank, the input end of the second upper water pump is connected to the upper part of the water tank through a long pipe, one end of the second lower spiral pipe is connected to the output end of the second lower water pump, the other end of the second lower spiral pipe is connected to the lower part of the water tank, the input end of the second lower water pump is connected to the lower part of the water tank, and the water tank is filled with water.

[0013] Preferably: the power generation module includes a first liquid piston, a second liquid piston and a hydroelectric generator set, the first liquid piston and the second liquid piston are cylindrical shells with a cavity, the cavity is filled with liquid (water), and the water is driven to rise and fall in the cavity by gas, the upper inlet of the first liquid piston and the upper inlet of the second liquid piston are both connected to the air storage module, the upper outlet of the first liquid piston and the upper outlet of the second liquid piston are both connected to the expander, the upper inlet and outlet in this section can be used to transport gas, the lower outlet of the first liquid piston is connected to the lower inlet of the second liquid piston through the hydroelectric generator set, the lower inlet of the first liquid piston is connected to the lower outlet of the second liquid piston through the hydroelectric generator set, and the lower inlet of the first liquid piston is connected to the lower outlet of the second liquid piston through the hydroelectric generator set, and the lower inlet and outlet in this section are used to transport liquid.

[0014] Preferably: the power generation module also includes a first airbag accumulator, a second airbag accumulator, a first valve, a second valve, a third valve and a fourth valve, one end of the hydroelectric generator set is connected to the first opening of the first three-way pipe, the lower outlet of the first liquid piston is connected to the second opening of the first three-way pipe through the second valve, the first airbag accumulator is arranged between the lower outlet of the first liquid piston and the second valve, the lower outlet of the second liquid piston is connected to the third opening of the first three-way pipe through the first valve, the second airbag accumulator is arranged between the lower outlet of the second liquid piston and the first valve, the other end of the hydroelectric generator set is connected to the first opening of the second three-way pipe, the lower inlet of the first liquid piston is connected to the second opening of the second three-way pipe through the third valve, and the lower inlet of the second liquid piston is connected to the third opening of the second three-way pipe through the fourth valve.

[0015] Preferably: the compression-expansion mechanical module further comprises a fifth valve and a sixth valve, the fifth valve is arranged on the pipeline between the piston cavity outlet of the piston compressor and the inlet of the first air storage tank, and the sixth valve is arranged on the piston cavity inlet pipeline of the piston compressor;

[0016] The storage module is an air storage module, and the storage module further includes a seventh valve and an eighth valve, one end of the first connecting pipe is connected to the outlet of the first air storage tank, the middle part of the first connecting pipe is connected to the inlet and outlet of the second air storage tank, the other end of the first connecting pipe is connected to the first opening of the third three-way pipe, the seventh valve is arranged between the outlet of the first air storage tank and the inlet and outlet of the second air storage tank, and the eighth valve is arranged between the inlet and outlet of the second air storage tank and the first opening of the third three-way pipe;

[0017] The power generation module also includes a ninth valve, a tenth valve, an eleventh valve and a twelfth valve. The second opening of the third three-way pipe is connected to the upper inlet of the first liquid piston, the third opening of the third three-way pipe is connected to the upper inlet of the second liquid piston, the eleventh valve is arranged between the second opening of the third three-way pipe and the upper inlet of the first liquid piston, the twelfth valve is arranged between the third opening of the third three-way pipe and the upper inlet of the second liquid piston, the ninth valve is arranged at the upper outlet of the first liquid piston, the tenth valve is arranged at the upper outlet of the second liquid piston, one end of the second connecting pipe is connected to the tenth valve, the middle part of the second connecting pipe is connected to the ninth valve, the other end of the second connecting pipe is connected to the expander, and the valve can be an electromagnetic valve.

[0018] Preferably: the air storage module further comprises a first pressure sensor and a second pressure sensor, the first pressure sensor is installed in the first air storage tank, and the second pressure sensor is installed in the second air storage tank;

[0019] The power generation module also includes a third pressure sensor and a fourth pressure sensor. The third pressure sensor is installed in the upper part of the first liquid piston, and the fourth pressure sensor is installed in the upper part of the second liquid piston.

[0020] An operating method of a hydraulic compressed air hybrid energy storage power generation system, using a hydraulic compressed air hybrid energy storage power generation system, comprising the following steps: a pressure presetting process, an energy storage process, and a power generation process;

[0021] Step 1: Pressure preset process:

[0022] During the pressure preset process, the seventh valve remains open; the working conditions of the pressure preset process include: the piston upward situation and the piston downward situation;

[0023] Step 1.1: Piston upward movement:

[0024] When the piston moves upward, the sixth valve is closed, the eighth valve is closed, and the piston in the piston compressor is pushed upward, pushing the water in the piston cavity upward to compress the air; when the air pressure is consistent with the air pressure in the first air storage tank, the fifth valve is opened, and the air in the piston compressor cavity is discharged into the first air storage tank and the second air storage tank; when the piston in the piston compressor reaches the highest point, the fifth valve is closed, switching to the piston downward situation;

[0025] Step 1.2, piston downward situation:

[0026] When the piston moves downward, the sixth valve opens, the piston in the piston compressor moves downward, the air volume in the piston cavity increases, and under the action of negative pressure, the outside air is sucked into the piston cavity; when the piston moves to the lowest point, the sixth valve closes, switching to the piston upward situation;

[0027] Step 1.3, repeat the piston downward and upward process for multiple times, when the average value of the pressure measured by the first pressure sensor and the second pressure sensor reaches the set pressure p0, the piston compressor stops, the fifth valve is closed, and the pressure preset process ends;

[0028] Step 2: Energy storage conditions:

[0029] The energy storage operating conditions include two operating conditions: the first gas storage tank and the second gas storage tank storing energy together and the first gas storage tank storing energy alone;

[0030] Step 2.1: The first gas tank and the second gas tank store energy together:

[0031] The fifth valve is opened; the piston compressor operates with the piston moving upward and downward, and continuously fills the first gas tank and the second gas tank with compressed air to store energy; as the energy storage process continues, the air pressure in the first gas tank and the second gas tank continues to rise, and when the average value of the pressure measured by the first pressure sensor and the second pressure sensor reaches the set pressure p1, the seventh valve is closed, and the situation where the first gas tank and the second gas tank store energy together ends; the system enters the operation situation where the first gas tank stores gas alone;

[0032] Step 2.2: The first gas storage tank stores energy alone:

[0033] The piston compressor continues to operate during the piston upward and downward movement, compressing air into the first air tank to store energy; as air continues to enter the first air tank, the air pressure in the first air tank continues to rise; when the air pressure measured by the first pressure sensor reaches the set pressure p2, the first air tank ends storing energy alone, and the piston compressor stops; p2>p1>p0;

[0034] Step 3: Power generation stage:

[0035] During power generation operation, there are three situations including the first liquid piston intake, the second liquid piston intake, and the first gas storage tank replenishing gas from the second gas storage tank;

[0036] Step 3.1, first liquid piston intake situation:

[0037] The second valve, the fourth valve, the tenth valve, the eleventh valve and the eighth valve are opened, the air in the second gas storage tank expands and enters the first liquid piston, squeezing the water at the bottom of the first liquid piston to the hydro-generator set to generate power; the water after power generation returns to the second liquid piston, squeezing the air at the top of the second liquid piston to the expander to generate power, and the gas after work returns to the external environment; when the water level in the first liquid piston reaches the lower limit water level, the second valve, the fourth valve, the tenth valve and the eleventh valve are closed, switching to the second liquid piston air intake situation for operation;

[0038] Step 3.2, second liquid piston intake situation:

[0039] The first valve, the third valve, the ninth valve, and the twelfth valve are opened, the air in the second air storage tank expands and enters the second liquid piston, the water at the bottom of the second liquid piston is discharged to the turbine generator set to generate power and then returns to the first liquid piston, the air on the top of the first liquid piston is squeezed out to the expander to generate power and then returns to the external environment; when the water level in the second liquid piston reaches the lower limit water level, the state is switched to the first liquid piston intake; the first valve, the third valve, the ninth valve, and the twelfth valve are closed;

[0040] As the power generation process continues, the air pressure in the second gas tank decreases. When the air pressure in the second gas tank drops to p0, the second gas tank enters the first gas tank to replenish air.

[0041] Step 3.3: The gas storage tank 22 replenishes gas to the gas storage tank 21:

[0042] During this process, valve 909 is opened, the air in the first air tank flows to the second air tank, and the air pressure in the second air tank rises. When the air pressure in the second air tank rises to the set pressure p1, the air replenishment process ends. In step 3.3, the system is still continuing to enter the first liquid piston air intake and the second liquid piston air intake process;

[0043] During the air replenishment process, the air pressure in the first air tank decreases. After multiple air replenishment operations, when the pressure value measured by the first pressure sensor drops to p1, the seventh valve is normally open, and the air in the first air tank and the second air tank expands together to do work; when the pressure values ​​measured by the first pressure sensor and the second pressure sensor are both less than p0, the power generation process ends.

[0044] Preferably: in steps one and two, when storing energy, the heat exchange device is started to reduce the temperature of the first air tank and the second air tank; when the air in the piston cavity is discharged into the first air tank and the second air tank, the air in the first air tank and the second air tank is compressed, and the air pressure and temperature both rise; in this process, the first upper water pump is started to pass water into the first upper spiral pipe in the first air tank to absorb the heat released when the air is compressed, and the rate of increase of the air temperature in the first air tank is slowed down; the second upper water pump is started to pass water into the second upper spiral pipe in the second air tank to absorb the heat released when the air is compressed, and the increase in the air temperature in the second air tank is reduced; in this During the process, the water temperature rises slightly; when generating electricity, the enhanced heat exchange device is started to increase the temperature of the first air tank and the second air tank; when the air in the first air tank expands, the air pressure and temperature both decrease; during this process, the first lower water pump is started to pass water into the first lower spiral pipe in the first air tank to replenish the heat absorbed during the expansion of the air, and the rate of decrease of the air temperature in the first air tank is slowed down; when the air in the second air tank expands, the air pressure and temperature both decrease, and the second lower water pump is started to pass water into the second lower spiral pipe in the second air tank to replenish the heat absorbed during the expansion of the air, and the rate and amplitude of the decrease of the air temperature in the second air tank are reduced.

[0045] The present invention has the following beneficial effects:

[0046] 1) The present invention improves the problem of limited site selection of pumped storage technology by using gas storage tanks to store gas and water, and the site selection is more flexible;

[0047] 2) The present invention reduces the operating head amplitude of the hydraulic machinery by using the air storage tank to replenish air, thereby improving the operating efficiency and stability of the hydraulic machinery;

[0048] 3) The present invention adds a spiral pipe in the first air storage tank and the second air storage tank, which enhances the heat transfer performance during air compression and expansion, improves the round-trip efficiency during air compression and expansion, and has high energy utilization;

[0049] 4) The energy storage system described in the present invention has all mature equipment, and does not require additional fossil fuel consumption during energy storage and power generation, and does not cause environmental pollution;

[0050] 5) The energy storage efficiency can reach over 70% after the system is scaled up. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 It is a hydraulic compressed air hybrid energy storage power generation system.

[0052] Figure 2 The present invention is a hydraulic compressed air hybrid energy storage power generation system according to a third specific implementation mode.

[0053] Figure 3 The present invention is a hydraulic compressed air hybrid energy storage power generation system according to a fourth specific implementation mode.

[0054] In the figure, 1-piston compressor, 101-spraying equipment, 4-hydraulic generator set, 5-expander, 21-first air storage tank, 22-second air storage tank, 23-water tank, 31-first liquid piston, 32-second liquid piston, 51-first expander, 52-second expander, 61-first air bag accumulator, 62-second air bag accumulator, 71-first lower water pump, 72-first upper water pump, 73-second lower water pump, 74-second upper water pump, 81-first pressure sensor, 82-second pressure sensor, 83-second Three pressure sensors, 84-fourth pressure sensor, 901-first valve, 902-second valve, 903-third valve, 904-fourth valve, 905-ninth valve, 906-tenth valve, 907-eleventh valve, 908-twelfth valve, 909-seventh valve, 910-eighth valve, 911-fifth valve, 912-sixth valve, 913-thirteenth valve, 914-fourteenth valve, 915-fifteenth valve, 916-sixteenth valve, 917-seventeenth valve, 918-eighteenth valve. DETAILED DESCRIPTION

[0055] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is described below by the specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.

[0056] Specific implementation method 1: Combination Figures 1 to 3 To illustrate this embodiment, a hydraulic compressed air hybrid energy storage power generation system of this embodiment includes a compression expansion mechanical module, an air storage module and a power generation module;

[0057] Compression expansion mechanical module: used to compress gas (air) and transport the compressed gas to the air storage module;

[0058] The compression-expansion mechanical module includes a piston compressor 1 and an expander 5, wherein the piston compressor 1 includes a piston cavity and a piston, wherein a piston that can slide up and down is arranged in the piston cavity, wherein the piston cavity has an inner cavity with an opening at the bottom, wherein a sealing ring is arranged at the connecting portion between the piston cavity and the piston, wherein the lower portion of the piston is connected to the driving end of a driving device (such as a linear motor or a hydraulic rod) to realize the up and down movement of the piston in the inner cavity of the piston cavity, wherein the gas is supplemented and compressed by changing the distance between the upper side of the piston and the upper portion of the inner cavity of the piston cavity, wherein the relative position of the driving device housing and the piston cavity is fixed, namely, the driving device housing and the piston cavity can be bolted to the same bracket, wherein an outlet and an inlet are arranged at the upper portion of the piston cavity, wherein the piston compressor 1 is connected to the air storage module, and the expander 5 is connected to the power generation module;

[0059] The compression expansion mechanical module also includes a spray device 101, the nozzle of which is arranged at the upper part of the inner cavity of the piston cavity, and the spray device 101 is connected to the lower part of the water supply tank, and is used to spray water into the inner cavity of the piston cavity to cool it down, and at the same time increase the moisture content in the air, and reduce the evaporation of water in the power generation module;

[0060] The compression-expansion mechanical module further includes a fifth valve 911 and a sixth valve 912. The fifth valve 911 is provided on the pipeline between the piston cavity outlet of the piston compressor 1 and the inlet of the first air storage tank 21, and the sixth valve 912 is provided on the piston cavity inlet pipeline of the piston compressor 1.

[0061] Air storage module: used to receive gas from the compression and expansion mechanical module for energy storage, and then transmit the stored energy to the power generation module;

[0062] The air storage module includes a first air storage tank 21, a second air storage tank 22 and an enhanced heat exchange device. The piston cavity outlet of the piston compressor 1 is connected to the inlet of the first air storage tank 21, and the outlet of the first air storage tank 21 is connected to the inlet and outlet of the second air storage tank 22. The outlet of the first air storage tank 21 and the inlet and outlet of the second air storage tank 22 are both connected to the power generation module. The first air storage tank 21 and the second air storage tank 22 are connected to the enhanced heat exchange device. The first air storage tank 21 can supply air alone and replenish air to the second air storage tank 22.

[0063] The air storage module further includes a seventh valve 909 and an eighth valve 910, one end of the first connecting pipe is connected to the outlet of the first air storage tank 21, the middle part of the first connecting pipe is connected to the inlet and outlet of the second air storage tank 22, the other end of the first connecting pipe is connected to the first opening of the third three-way pipe, the seventh valve 909 is arranged between the outlet of the first air storage tank 21 and the inlet and outlet of the second air storage tank 22, and the eighth valve 910 is arranged between the inlet and outlet of the second air storage tank 22 and the first opening of the third three-way pipe;

[0064] The air storage module further includes a first pressure sensor 81 and a second pressure sensor 82. The first pressure sensor 81 is installed in the first air storage tank 21, and the second pressure sensor 82 is installed in the second air storage tank 22. The present invention reduces the operating head amplitude of the hydraulic machinery by using the air storage tank to replenish air, thereby improving the operating efficiency and stability of the hydraulic machinery.

[0065] The enhanced heat exchange device includes a water tank 23, a first lower water pump 71, a first upper water pump 72, a second lower water pump 73, a second upper water pump 74, a first lower spiral pipe, a first upper spiral pipe, a second lower spiral pipe and a second upper spiral pipe. The water tank 23, the first lower water replenishment valve 915, the first lower water pump 71 and the first lower spiral pipe are connected in a circular manner. The water tank 23, the first upper water replenishment valve 913, the first upper water pump 72 and the first upper spiral pipe are connected in a circular manner. The water tank 23, the second upper water supply valve 914, the second upper water pump 74, and the second upper spiral pipeline are connected in a circular manner, and the water tank 23, the second lower water supply valve 916, the second lower water pump 73, and the second lower spiral pipeline are connected in a circular manner, that is, the first upper spiral pipeline and the first lower spiral pipeline arranged above and below are installed inside the first air storage tank 21, one end of the first upper spiral pipeline is connected to the output end of the first upper water pump 72, and the other end of the first upper spiral pipeline is connected to the water tank 23 The upper part is connected, the input end of the first upper water pump 72 is connected to the upper part of the water tank through a long tube, one end of the first lower spiral pipe is connected to the output end of the first lower water pump 71, and the other end of the first lower spiral pipe is connected to the lower part of the water tank. The second upper spiral pipe and the second lower spiral pipe arranged above and below are installed inside the second air storage tank 22, one end of the second upper spiral pipe is connected to the output end of the second upper water pump 74, and the other end of the second upper spiral pipe is connected to the upper part of the water tank. The input end of the second upper water pump 74 is connected to the upper part of the water tank through another long pipe, one end of the second lower spiral pipe is connected to the output end of the second lower water pump 73, and the other end of the second lower spiral pipe is connected to the lower part of the water tank. The input end of the second lower water pump 73 is connected to the lower part of the water tank, and the water tank is full of water; the present invention adds spiral pipes in the first air storage tank 21 and the second air storage tank 22, thereby enhancing the heat transfer performance during air compression and expansion, and improving the round-trip efficiency during air compression and expansion;

[0066] Power generation module: converts the pressure potential energy generated by the high-pressure gas stored in the air storage module into electrical energy;

[0067] The power generation module includes a first liquid piston 31, a second liquid piston 32 and a hydroelectric generator set 4. The first liquid piston 31 and the second liquid piston 32 are cylindrical or cubic shells with cavities. The cavities are filled with liquid (water). The water is driven to rise and fall in the cavities by gas. The upper inlet of the first liquid piston 31 and the upper inlet of the second liquid piston 32 are both connected to the air storage module. The upper outlet of the first liquid piston 31 and the upper outlet of the second liquid piston 32 are both connected to the expander 5. The upper inlet and outlet in this section can be used to transport gas. The lower outlet of the first liquid piston 31 is connected to the lower inlet of the second liquid piston 32 through the hydroelectric generator set 4. The lower inlet of the first liquid piston 31 is connected to the lower outlet of the second liquid piston 32 through the hydroelectric generator set 4. The lower inlet and outlet in this section are used to transport liquid.

[0068] The power generation module also includes a first airbag accumulator 61, a second airbag accumulator 62, a first valve 901, a second valve 902, a third valve 903 and a fourth valve 904. One end of the hydroelectric generator set 4 is connected to the first opening of the first three-way pipe, the lower outlet of the first liquid piston 31 is connected to the second opening of the first three-way pipe through the second valve 902, the first airbag accumulator 61 is arranged between the lower outlet of the first liquid piston 31 and the second valve 902, the lower outlet of the second liquid piston 32 is connected to the third opening of the first three-way pipe through the first valve 901, the second airbag accumulator 62 is arranged between the lower outlet of the second liquid piston 32 and the first valve 901, the other end of the hydroelectric generator set 4 is connected to the first opening of the second three-way pipe, the lower inlet of the first liquid piston 31 is connected to the second opening of the second three-way pipe through the third valve 903, and the lower inlet of the second liquid piston 32 is connected to the third opening of the second three-way pipe through the fourth valve 904;

[0069] The power generation module also includes a ninth valve 905, a tenth valve 906, an eleventh valve 907 and a twelfth valve 908. The second opening of the third three-way pipe is connected to the upper inlet of the first liquid piston 31, the third opening of the third three-way pipe is connected to the upper inlet of the second liquid piston 32, the eleventh valve 907 is arranged between the second opening of the third three-way pipe and the upper inlet of the first liquid piston 31, the twelfth valve 908 is arranged between the third opening of the third three-way pipe and the upper inlet of the second liquid piston 32, the ninth valve 905 is arranged at the upper outlet of the first liquid piston 31, the tenth valve 906 is arranged at the upper outlet of the second liquid piston 32, one end of the second connecting pipe is connected to the tenth valve 906, the middle part of the second connecting pipe is connected to the ninth valve 905, the other end of the second connecting pipe is connected to the expander 5, and the valve can be a solenoid valve; the various devices of the energy storage system described in the present invention are relatively mature, and no additional consumption of fossil fuels is required during energy storage and power generation, and no environmental pollution is generated; the energy storage efficiency of the system after large-scale operation can reach more than 70%;

[0070] The power generation module further includes a third pressure sensor 83 and a fourth pressure sensor 84 . The third pressure sensor 83 is installed at the upper inner portion of the first liquid piston 31 , and the fourth pressure sensor 84 is installed at the upper inner portion of the second liquid piston 32 .

[0071] Specific implementation method 2: Combination Figure 1 The present embodiment is described. The present embodiment is a method for operating a hydraulic compressed air hybrid energy storage power generation system, which uses a hydraulic compressed air hybrid energy storage power generation system, including a compression expansion mechanical module, an air storage module and a power generation module;

[0072] The compression-expansion mechanical module comprises a piston compressor 1, an expander 5, a fifth valve 911, a sixth valve 912 and a spray device 101; wherein the piston chamber of the piston compressor is connected to the first gas storage tank 21 and the external environment respectively through two pipes; the expander is connected to the first liquid piston 31 and the second liquid piston 32 through a pipe;

[0073] The air storage module includes a first air storage tank 21, a second air storage tank 22, a water tank 23, a first lower water pump 71, a first upper water pump 72, a second lower water pump 73, a second upper water pump 74 and a seventh valve 909; wherein the first air storage tank 21 and the second air storage tank 22 are connected via a pipeline; spiral pipes are respectively installed in the upper and lower parts of the first air storage tank 21; the lower pipe is connected to the lower first water pump 71 for passing normal temperature water to cool the air; The pipe at the bottom is connected to the upper first water pump 72, which is used to pass the heated water to heat the air; the upper part and the lower part of the second air storage tank 22 are respectively installed with spiral pipes; the lower pipe is connected to the second lower water pump 73, which is used to pass 25°C normal temperature water to cool the air; the upper pipe is connected to the second upper water pump 74, which is used to pass the heated water to heat the air; the first air storage tank 21 is installed with a first pressure sensor 81, and the second air storage tank 22 is installed with a second pressure sensor 82;

[0074] The power generation module includes a first liquid piston 31, a second liquid piston 32, a hydroelectric generator set 4, a first airbag accumulator 61, a second airbag accumulator 62, a third pressure sensor 83, a fourth pressure sensor 84, a first valve 901, a second valve 902, a third valve 903, a fourth valve 904, a ninth valve 905, a tenth valve 906, an eleventh valve 907 and a twelfth valve 908. Two pipes are connected to the top of the first liquid piston 31, respectively connected to the expander and the second gas storage tank 22; two pipes are connected to the top of the second liquid piston 32, respectively connected to the expander and the second gas storage tank 22; two parallel pipes are connected between the first liquid piston 31 and the second liquid piston 32, and two airbag accumulators are connected to the upper pipe; and a hydroelectric generator set is connected between the two pipes through the pipe;

[0075] The compression-expansion mechanical module comprises a piston compressor 1, an expander 5, a fifth valve 911, a sixth valve 912 and a spray device 101; when storing energy, the air in the piston cavity is first compressed and then discharged into the first air storage tank 21 and the second air storage tank 22; when the air in the piston cavity is completely discharged, the piston cavity absorbs air from the external environment; a spray device 101 is installed on the top of the piston cavity, which is used to enhance the heat transfer performance between air and water and reduce the air temperature fluctuation when the air is compressed;

[0076] The method comprises the following steps: a pressure presetting process, an energy storage process, and a power generation process;

[0077] Step 1: Pressure preset process:

[0078] During the pressure preset process, the seventh valve 909 remains open; the working conditions of the pressure preset process include: the piston upward situation and the piston downward situation;

[0079] Step 1.1: Piston upward movement:

[0080] When the piston moves upward, the sixth valve 912 is closed, the eighth valve 910 is closed, and the piston in the piston compressor 1 is pushed upward, pushing the water in the piston cavity upward to compress the air; when the air pressure is consistent with the air pressure in the first air storage tank 21, the fifth valve 911 is opened, and the air in the piston compressor 1 cavity is discharged into the first air storage tank 21 and the second air storage tank 22; when the piston in the piston compressor 1 reaches the highest point, the fifth valve 911 is closed, switching to the piston downward state;

[0081] Step 1.2, piston downward situation:

[0082] When the piston moves downward, the sixth valve 912 opens, the piston in the piston compressor 1 moves downward, the air volume in the piston cavity increases, and under the action of negative pressure, the outside air is sucked into the piston cavity; when the piston moves to the lowest point, the sixth valve 912 closes, switching to the piston upward state;

[0083] Step 1.3, repeat the piston downward and upward process for multiple times. When the average value of the pressure measured by the first pressure sensor 81 and the second pressure sensor 82 reaches the set pressure p0, the piston compressor 1 is shut down, the fifth valve 911 is closed, and the pressure preset process ends;

[0084] Step 2: Energy storage conditions:

[0085] The energy storage operating condition includes two operating conditions: the first gas storage tank 21 and the second gas storage tank 22 store energy together, and the first gas storage tank 21 stores energy alone.

[0086] Step 2.1: The first gas storage tank 21 and the second gas storage tank 22 store energy together:

[0087] The fifth valve 911 is opened; the piston compressor 1 operates in the piston upward and piston downward conditions, and continuously fills the first air tank 21 and the second air tank 22 with compressed air to store energy; as the energy storage process continues, the air pressure in the first air tank 21 and the second air tank 22 continues to rise, and when the average value of the pressure measured by the first pressure sensor 81 and the second pressure sensor 82 reaches the set pressure p1, the seventh valve 909 is closed, and the situation where the first air tank 21 and the second air tank 22 store energy together ends; the system enters the operation state where the first air tank 21 stores air alone;

[0088] When the air in the piston cavity is discharged into the first air storage tank 21 and the second air storage tank 22, the air in the first air storage tank 21 and the second air storage tank 22 is compressed, and the air pressure and temperature both rise. In this process, the first lower water pump 71 is started to pass normal temperature water into the first air storage tank 21 to absorb the heat released when the air is compressed, thereby reducing the increase in the air temperature in the first air storage tank 21; the second lower water pump 73 is started to pass normal temperature water into the second air storage tank 22 to absorb the heat released when the air is compressed, thereby reducing the increase in the air temperature in the second air storage tank 22.

[0089] Step 2.2: The first gas storage tank 21 stores energy alone:

[0090] The piston compressor 1 continues to operate during the piston upward and downward movement, compressing air into the first air storage tank 21 to store energy; as air continues to enter the first air storage tank 21, the air pressure in the first air storage tank 21 continues to rise; when the air pressure measured by the first pressure sensor 81 reaches the set pressure p2, the situation where the air storage tank 21 stores energy alone ends, and the piston compressor 1 stops; p2>p1>p0;

[0091] When the air in the piston cavity is discharged into the first air storage tank 21, the air in the first air storage tank 21 is compressed, and the air pressure and temperature both rise. In this process, the first lower water pump 71 is started to pass normal temperature water into the first air storage tank 21 to absorb the heat released when the air is compressed, thereby reducing the increase in the air temperature in the first air storage tank 21.

[0092] Step 3: Power generation stage:

[0093] During power generation operation, there are three situations, including air intake by the first liquid piston 31, air intake by the second liquid piston 32, and air replenishment from the first air storage tank 21 to the second air storage tank 22;

[0094] Step 3.1, the first liquid piston 31 intakes air:

[0095] The second valve 902, the fourth valve 904, the tenth valve 906, the eleventh valve 907 and the eighth valve 910 are opened, and the first valve 901, the third valve 903, the ninth valve 905 and the twelfth valve 908 are closed, and the air in the second gas storage tank 22 expands and enters the first liquid piston 31, and squeezes the water at the bottom of the first liquid piston 31 to the hydro-generator set 4 to generate power; the water after power generation returns to the second liquid piston 32, and squeezes the air at the top of the second liquid piston 32 to the expander 5 to generate power, and the gas after work returns to the external environment; when the water level in the first liquid piston 31 reaches the lower limit water level, the second valve 902, the fourth valve 904, the tenth valve 906 and the eleventh valve 907 are closed, and the operation is switched to the second liquid piston 32 intake state;

[0096] Step 3.2: The second liquid piston 32 is inlet:

[0097] The first valve 901, the third valve 903, the ninth valve 905, and the twelfth valve 908 are opened, the air in the second air storage tank 22 expands and enters the second liquid piston 32, the water at the bottom of the second liquid piston 32 is discharged to the hydro-generator set 4 to generate power and then returns to the first liquid piston 31, the air on the top of the first liquid piston 31 is squeezed out to the expander 5 to generate power and then returns to the external environment; when the water level in the second liquid piston 32 reaches the lower limit water level, the state is switched to the first liquid piston 31 to take in air; the first valve 901, the third valve 903, the ninth valve 905, and the twelfth valve 908 are closed;

[0098] As the power generation process continues, the air pressure in the second air tank 22 decreases. When the air pressure in the second air tank 22 drops to p0, the second air tank 22 replenishes air to the first air tank 21.

[0099] Step 3.3, the gas storage tank 22 replenishes gas to the gas storage tank 21:

[0100] During this process, the valve 909 is opened, the air in the first air tank 21 flows to the second air tank 22, and the air pressure in the second air tank 22 rises. When the air pressure in the second air tank 22 rises to the set pressure p1, the air replenishment process ends. In step 3.3, the system is still continuing the process of air intake by the first liquid piston 31 and the second liquid piston 32;

[0101] During the air replenishment process, the air pressure in the first air storage tank 21 decreases. After multiple air replenishment operations, when the pressure value measured by the pressure sensor 81 decreases to p1, the seventh valve 909 is normally open, and the air in the first air storage tank 21 and the second air storage tank 22 expands together to do work; when the pressure values ​​measured by the first pressure sensor 81 and the second pressure sensor 82 are both less than p0, the power generation process ends;

[0102] The present invention improves the problem of limited site selection of pumped storage technology by adopting the method of storing gas and water in gas storage tanks, and the site selection is more flexible; at the same time, the gas storage can not only be used to drive the water storage method hydroelectric generator set to generate electricity, but also can be recycled and reused to drive the expander 5 to generate electricity;

[0103] In steps 1 and 2, when the piston moves upward, the air is compressed, and the spray device 101 sprays spray droplets to enhance the heat transfer performance between the air and water in the inner cavity, reduce the increase in air temperature, and reduce compression power consumption;

[0104] When storing energy, the enhanced heat exchange device is started to reduce the temperature of the first air tank 21 and the second air tank 22; when the air in the piston cavity is discharged into the first air tank 21 and the second air tank 22, the air in the first air tank 21 and the second air tank 22 is compressed, and the air pressure and temperature both rise; in this process, the first upper water pump 72 is started to pass normal temperature water into the first upper spiral pipe in the first air tank 21 to absorb the heat released when the air is compressed, and the rate of increase of the air temperature in the first air tank 21 is slowed down; the second upper water pump 74 is started to pass normal temperature water into the second upper spiral pipe in the second air tank 22 to absorb the heat released when the air is compressed, and the rate of increase of the air temperature in the second air tank 22 is reduced; During this process, the water temperature rises slightly; when generating electricity, the enhanced heat exchange device is started to increase the temperature of the first air tank 21 and the second air tank 22; when the air in the first air tank 21 expands, the air pressure and temperature both decrease; during this process, the first lower water pump 71 is started to pass water into the first lower spiral pipe in the first air tank 21 to replenish the heat absorbed during the expansion of the air, and the rate of decrease of the air temperature in the first air tank 21 is slowed down; when the air in the second air tank 22 expands, the air pressure and temperature both decrease, and the second lower water pump 73 is started to pass water into the second lower spiral pipe in the second air tank 22 to replenish the heat absorbed during the expansion of the air, thereby reducing the rate and amplitude of the decrease of the air temperature in the second air tank 22.

[0105] Specific implementation method three: Combination Figure 2 The present embodiment is described. The present embodiment is a hydraulic compressed air hybrid energy storage power generation system. The difference between the present specific embodiment three and the specific embodiments one and two is that: the present specific embodiment three is provided with a two-stage (two) piston compressor, and the first piston compressor 11 is connected in series with the piston compressor 1. The air will be compressed by the first piston compressor 11 and the piston compressor 1 respectively and then enter the first air storage tank 21 and the second air storage tank 22 for storage; in the present embodiment, a seventeenth valve 917 is added after the inlet of the piston compressor 11, and the first expander 51 is connected after the expander 5. The air discharged by the first liquid piston 31 and the second liquid piston 32 will undergo expansion work by the expander 5 and the first expander 51 before being discharged into the external environment.

[0106] Specific implementation method four: Combination Figure 3The present embodiment is described. The present embodiment is a hydraulic compressed air hybrid energy storage power generation system. The difference between the present specific embodiment 4 and the specific embodiments 1, 2 and 3 is that: the present specific embodiment 4 is provided with a three-stage piston compressor, the second piston compressor 12, the first piston compressor 11 and the piston compressor 1 are connected in series in sequence, and the air will be compressed by the second piston compressor 12, the first piston compressor 11 and the piston compressor 1 respectively before entering the first air storage tank 21 and the second air storage tank 22 for storage; in this embodiment, a seventeenth valve 917 is added after the first piston compressor 11, and an eighteenth valve 918 is added after the second piston compressor 12, the first expander 51 is connected after the expander 5, and the second expander 52 is connected after the first expander 51, and the air discharged by the liquid piston 31 and the liquid piston 32 will be discharged into the external environment after undergoing expansion work of the expander 5, the first expander 51 and the second expander 52.

[0107] It should be noted that in the above embodiments, as long as the technical solutions are not contradictory, they can be arranged and combined, and those skilled in the art can exhaust all possibilities based on the mathematical knowledge of arrangement and combination. Therefore, the present invention will no longer describe the technical solutions after arrangement and combination one by one, but it should be understood that the technical solutions after arrangement and combination have been disclosed by the present invention.

[0108] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A hydraulic compressed air hybrid energy storage power generation system, characterized in that: It includes a compression expansion mechanical module, a storage module and a power generation module; Compression expansion mechanical module: used to compress gas and transport the compressed gas to the storage module; Storage module: used to receive the gas from the compression and expansion mechanical module for energy storage, and then transmit the stored energy to the power generation module; Power generation module: converts the energy stored in the air storage module into electrical energy.

2. A hydraulic compressed air hybrid energy storage power generation system according to claim 1, characterized in that: The compression-expansion mechanical module comprises a piston compressor (1) and an expander (5), wherein the piston compressor (1) comprises a piston cavity and a piston, wherein a piston is slidably arranged in the piston cavity, the piston compressor (1) is connected to the storage module, and the expander (5) is connected to the power generation module.

3. A hydraulic compressed air hybrid energy storage power generation system according to claim 2, characterized in that: The storage module comprises a first gas storage tank (21), a second gas storage tank (22) and a heat exchange device, the outlet of the piston compressor (1) is connected to the inlet of the first gas storage tank (21), the outlet of the first gas storage tank (21) is connected to the inlet and outlet of the second gas storage tank (22), the outlet of the first gas storage tank (21) and the inlet and outlet of the second gas storage tank (22) are both connected to the power generation module, and the first gas storage tank (21) and the second gas storage tank (22) are connected to the heat exchange device.

4. A hydraulic compressed air hybrid energy storage power generation system according to claim 3, characterized in that: The storage module also includes a heat exchange device, which includes a water tank (23), a first lower water pump (71), a first upper water pump (72), a second lower water pump (73), a second upper water pump (74), a first lower spiral pipe, a first upper spiral pipe, a second lower spiral pipe and a second upper spiral pipe. The first upper spiral pipe and the first lower spiral pipe are installed in the first gas storage tank (21) and the first upper spiral pipe is connected to the first upper water pump (72). The second upper spiral pipe and the second lower spiral pipe are installed in the second gas storage tank (22) and the second upper spiral pipe is connected to the second upper water pump (74).

5. A hydraulic compressed air hybrid energy storage power generation system according to claim 4, characterized in that: The power generation module comprises a first liquid piston (31), a second liquid piston (32) and a hydroelectric generator set (4); the upper inlet of the first liquid piston (31) and the upper inlet of the second liquid piston (32) are both connected to the air storage module; the upper outlet of the first liquid piston (31) and the upper outlet of the second liquid piston (32) are both connected to the expansion machine (5); the lower outlet of the first liquid piston (31) is connected to the lower inlet of the second liquid piston (32) through the hydroelectric generator set (4); and the lower inlet of the first liquid piston (31) is connected to the lower outlet of the second liquid piston (32) through the hydroelectric generator set (4).

6. A hydraulic compressed air hybrid energy storage power generation system according to claim 5, characterized in that: The power generation module further comprises a first airbag accumulator (61), a second airbag accumulator (62), a first valve (901), a second valve (902), a third valve (903) and a fourth valve (904); one end of the hydroelectric generator set (4) is connected to a first opening of the first three-way pipe; a lower outlet of the first liquid piston (31) is connected to a second opening of the first three-way pipe through the second valve (902); a first airbag accumulator (61) is arranged between the lower outlet of the first liquid piston (31) and the second valve (902); The lower outlet of the plug (32) is connected to the third opening of the first three-way pipe through the first valve (901), a second air bag accumulator (62) is arranged between the lower outlet of the second liquid piston (32) and the first valve (901), the other end of the hydroelectric generator set (4) is connected to the first opening of the second three-way pipe, the lower inlet of the first liquid piston (31) is connected to the second opening of the second three-way pipe through the third valve (903), and the lower inlet of the second liquid piston (32) is connected to the third opening of the second three-way pipe through the fourth valve (904).

7. A hydraulic compressed air hybrid energy storage power generation system according to claim 6, characterized in that: The compression-expansion mechanical module further comprises a fifth valve (911) and a sixth valve (912), wherein the fifth valve (911) is arranged on the pipeline between the outlet of the piston compressor (1) and the inlet of the first air storage tank (21), and the sixth valve (912) is arranged on the inlet pipeline of the piston compressor (1); The storage module further comprises a seventh valve (909) and an eighth valve (910), one end of the first connecting pipe is connected to the outlet of the first gas storage tank (21), the middle part of the first connecting pipe is connected to the inlet and outlet of the second gas storage tank (22), the other end of the first connecting pipe is connected to the first opening of the third three-way pipe, the seventh valve (909) is arranged between the outlet of the first gas storage tank (21) and the inlet and outlet of the second gas storage tank (22), and the eighth valve (910) is arranged between the inlet and outlet of the second gas storage tank (22) and the first opening of the third three-way pipe; The power generation module further comprises a ninth valve (905), a tenth valve (906), an eleventh valve (907) and a twelfth valve (908); the second opening of the third three-way pipe is connected to the upper inlet of the first liquid piston (31); the third opening of the third three-way pipe is connected to the upper inlet of the second liquid piston (32); the eleventh valve (907) is arranged between the second opening of the third three-way pipe and the upper inlet of the first liquid piston (31); the twelfth valve (908) is arranged between the third opening of the third three-way pipe and the upper inlet of the second liquid piston (32); the ninth valve (905) is arranged at the upper outlet of the first liquid piston (31); the tenth valve (906) is arranged at the upper outlet of the second liquid piston (32); one end of the second connecting pipe is connected to the tenth valve (906); the middle part of the second connecting pipe is connected to the ninth valve (905); and the other end of the second connecting pipe is connected to the expander (5).

8. A hydraulic compressed air hybrid energy storage power generation system according to claim 7, characterized in that: The storage module further comprises a first pressure sensor (81) and a second pressure sensor (82); the first pressure sensor (81) is installed in the first gas storage tank (21), and the second pressure sensor (82) is installed in the second gas storage tank (22); The power generation module further comprises a third pressure sensor (83) and a fourth pressure sensor (84). The third pressure sensor (83) is installed in the first liquid piston (31), and the fourth pressure sensor (84) is installed in the second liquid piston (32).

9. An operating method of a hydraulic compressed air hybrid energy storage power generation system, characterized in that: A hydraulic compressed air hybrid energy storage power generation system according to claim 7 or 8 comprises the following steps: Pressure presetting process: During the pressure preset process, the seventh valve (909) remains open; the working conditions of the pressure preset process include: the piston upward condition and the piston downward condition; Piston upward situation: When the piston moves upward, the sixth valve (912) is closed, and the piston in the piston compressor (1) is pushed upward, pushing the water in the piston cavity upward to compress the air; when the air pressure is consistent with the air pressure in the first air storage tank (21), the fifth valve (911) is opened, and the air in the piston compressor (1) cavity is discharged into the first air storage tank (21) and the second air storage tank (22); when the piston in the piston compressor (1) reaches the highest point, the fifth valve (911) is closed, switching to the piston downward state; Piston Downward Situation: When the piston moves downward, the sixth valve (912) opens, the piston in the piston compressor (1) moves downward, the volume of air in the piston cavity increases, and under the action of negative pressure, the outside air is sucked into the piston cavity; when the piston moves to the lowest point, the sixth valve (912) closes, switching to the piston upward state; The piston downward and upward processes are repeated multiple times. When the average value of the pressures measured by the first pressure sensor (81) and the second pressure sensor (82) reaches the set pressure p0, the piston compressor (1) is shut down, the fifth valve (911) is closed, and the pressure preset process ends. Energy storage conditions: It includes: a situation where the first gas storage tank (21) and the second gas storage tank (22) store energy together, and a situation where the first gas storage tank (21) stores energy alone; The first gas storage tank (21) and the second gas storage tank (22) store energy together: The fifth valve (911) is opened; the piston compressor (1) operates in the piston upward and piston downward conditions, and continuously fills the first air storage tank (21) and the second air storage tank (22) with compressed air to store energy; as the energy storage process continues, the air pressure in the first air storage tank (21) and the second air storage tank (22) continues to rise, and when the average value of the pressure measured by the first pressure sensor (81) and the second pressure sensor (82) reaches the set pressure p1, the seventh valve (909) is closed, and the situation of the first air storage tank (21) and the second air storage tank (22) storing energy together ends; The first gas storage tank (21) stores energy alone: The piston compressor (1) continues to operate during the piston upward and downward movement, compressing air into the first air storage tank (21) to store energy; as air continues to enter the first air storage tank (21), the air pressure in the first air storage tank (21) continues to rise; when the air pressure measured by the first pressure sensor (81) reaches the set pressure p2, the first air storage tank (21) ends storing energy alone, the piston compressor (1) stops, and the fifth valve (911) is closed; Power generation stage: The method includes the following situations: the first liquid piston (31) inhales air, the second liquid piston (32) inhales air, and the first air storage tank (21) replenishes air to the second air storage tank (22); Air intake condition of the first liquid piston (31): The second valve (902), the fourth valve (904), the tenth valve (906), the eleventh valve (907) and the eighth valve (910) are opened, the air in the second gas storage tank (22) expands and enters the first liquid piston (31), and squeezes the water at the bottom of the first liquid piston (31) to the hydro-generator set (4) to generate power; the water after power generation returns to the second liquid piston (32), and squeezes the air at the top of the second liquid piston (32) to the expander (5) to generate power, and the gas after power generation returns to the external environment; when the water level in the first liquid piston (31) reaches the lower limit water level, the second valve (902), the fourth valve (904), the tenth valve (906) and the eleventh valve (907) are closed, and the operation is switched to the second liquid piston (32) air intake state; Second liquid piston (32) intake condition: The first valve (901), the third valve (903), the ninth valve (905) and the twelfth valve (908) are opened, the air in the second air storage tank (22) expands and enters the second liquid piston (32), the water at the bottom of the second liquid piston (32) is discharged to the hydro-generator set (4) to generate power and then returns to the first liquid piston (31), the air above the first liquid piston (31) is squeezed out to the expander (5) to generate power and then returns to the external environment; when the water level in the second liquid piston (32) reaches the lower limit water level, the state is switched to the first liquid piston (31) to take in air; When the air pressure in the second air storage tank (22) drops to p0, the second air storage tank (22) enters the first air storage tank (21) to replenish air; The situation of gas storage tank 22 replenishing gas to gas storage tank 21: The seventh valve 909 is opened, and the air in the first air storage tank (21) flows to the second air storage tank (22), and the air pressure in the second air storage tank (22) rises. When the air pressure in the second air storage tank (22) rises to the set pressure p1, the air replenishment process ends, and the process of air intake by the first liquid piston (31) and the air intake by the second liquid piston (32) continues; During the air replenishment process, the air pressure in the first air storage tank (21) decreases. After multiple air replenishment operations, when the pressure value measured by the first pressure sensor (81) decreases to p1, the seventh valve (909) is normally open, and the air in the first air storage tank (21) and the second air storage tank (22) expand together to perform work; when the pressure values ​​measured by the first pressure sensor (81) and the second pressure sensor (82) are both less than p0, the power generation process ends.

10. The operating method of the hydraulic compressed air hybrid energy storage power generation system according to claim 9, characterized in that: When storing energy, the heat exchange device is started to absorb and store the heat generated when air is compressed, thereby reducing the air temperature in the first air storage tank (21) and the second air storage tank (22); when generating electricity, the heat exchange device is started to heat the air using the stored heat, thereby increasing the air temperature in the first air storage tank (21) and the second air storage tank (22).

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