Water-drive gas-storage energy-storage power station transformed from abandoned mine

Abstract

The invention discloses a water-drive gas-storage energy storage power station transformed from a waste mine, relates to the technical field of long-time large-scale energy storage power stations, and aims to construct the long-time large-scale energy storage power station by taking gas such as carbon dioxide as an energy storage medium and water as an energy conversion medium and by virtue of underground space resources of the existing mine. The underground space of the abandoned mine is divided into a reservoir, a water sump and a gas sump, and the gas sump is filled with high-pressure gas such as carbon dioxide and connected with the water sump through a communicating pipe; a water inlet pipe and a water return pipe are respectively communicated between the water sump and the reservoir, a hydroelectric generating set and a valve are arranged on the water inlet pipe, and a water pump is arranged on the water return pipe. The system is charged through the water pump, the power grid is discharged through the hydroelectric generating set, and the function of a long-time large-scale energy storage power station is achieved. Liquid carbon dioxide is adopted as an energy storage medium, and the national dual-carbon policy is met. The system is an extension of a pumped storage power station and air energy power generation, and the efficiency is better.

Description

Technical Field

[0001] The invention relates to the technical field of long-term large-scale energy storage power stations, and in particular to a water-driven gas-storage energy storage power station transformed from an abandoned mine. Background Art

[0002] Energy storage is a core energy issue in the context of dual carbon. Peak shaving, smart grids, and improving the efficiency of new energy sources such as photovoltaics and wind power that have been vigorously developed are all major demands for energy storage technology. Currently, technologies such as pumped storage power stations and gas energy storage are developing rapidly.

[0003] The construction of pumped storage power stations is restricted by the height difference between the upper and lower reservoirs and the geographical location, and is subject to the large scale of investment, long construction period and other constraints, and the development is uneven; the low energy efficiency, high energy consumption and high maintenance cost of compressed air energy storage restrict the application of air energy storage. The development and complementarity of multiple energy storage technologies are needed. At the same time, after decades of underground resource exploitation, a large number of abandoned mines have been formed, and the country is still growing at a rate of hundreds of millions of cubic meters per year. It is very meaningful and valuable to make full use of the millions of cubic meters of underground space formed by it to become an energy storage warehouse. Summary of the invention

[0004] The purpose of the present invention is to provide a water-driven gas-fired energy storage power station transformed from an abandoned mine to solve the problems existing in the above-mentioned prior art. It combines the existing pumped-storage power station and gas energy storage, does not require the upper and lower reservoir conditions with the elevation difference required by the pumped-storage power station, and has an energy conversion efficiency far higher than that of gas energy storage. The construction cost and operation cost of the power station are low.

[0005] To achieve the above-mentioned purpose, the present invention provides the following scheme: The present invention provides a water-driven gas storage energy power station transformed from an abandoned mine, comprising a water reservoir, a water tank and a gas tank, the underground space of the abandoned mine is divided into three chambers of the water reservoir, the water tank and the gas tank, the gas tank is filled with liquid carbon dioxide, and the gas tank is connected to the water tank through a connecting pipe; the water tank and the water reservoir are respectively connected with an inlet pipe and a return pipe, the inlet pipe is provided with a hydraulic generator and a valve, and the return pipe is provided with a water pump.

[0006] In one embodiment, photovoltaic power, wind power, and abandoned electricity during off-peak hours are used to pump water from the water reservoir to the water tank, and the gas volume in the water tank is reduced to pressurize the gas in the gas tank, compressing the carbon dioxide gas in the gas tank and converting the electrical energy into gas molecular internal energy for storage.

[0007] In one embodiment, the gas chamber is connected to a liquid storage tank via a liquid replenishing pipe, and a liquid replenishing valve is provided on the liquid storage tank.

[0008] In one embodiment, a saturated sodium bicarbonate solution is injected into the water tank.

[0009] In one embodiment, the water reservoir is an open water tank, and the water tank and the air tank are closed pressure chambers.

[0010] In one embodiment, a water replenishment pipeline is provided on the water reservoir, and a water replenishment valve is provided on the water replenishment pipeline, and the water reservoir is replenished with water through the water replenishment pipeline.

[0011] In one embodiment, a drainage pipe is provided at the bottom of the gas bin, and the seepage water is discharged from the drainage pipe by utilizing the gas pressure.

[0012] In one embodiment, the hydroelectric generator is connected to an electric power output device.

[0013] In one embodiment, the water pump is connected to an electric power input device.

[0014] Compared with the prior art, the present invention has achieved the following beneficial technical effects:

[0015] The power station transformed from an abandoned mine of the present invention includes a water reservoir, a water tank and a gas tank. The underground space of the abandoned mine is divided into three chambers: a water reservoir, a water tank and a gas tank. The gas tank is filled with liquid carbon dioxide, and the gas tank is connected to the water tank through a connecting pipe. The water tank and the water reservoir are respectively connected with an inlet pipe and a return pipe, a hydroelectric generator and a valve are arranged on the inlet pipe, and a water pump is arranged on the return pipe. The technology developed by combining the existing pumped storage power station and gas energy storage, and combining the principle of gas-liquid phase change energy storage, does not require the upper and lower reservoir conditions with elevation difference required by the pumped storage power station, and is much higher than the energy conversion efficiency of gas energy storage, and its construction cost and operation cost are low. Because liquid carbon dioxide is used as the energy storage medium, it complies with the national dual carbon policy. The present invention is an extension of pumped storage power station and air energy power generation, and its efficiency is better. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 The overall structural distribution diagram of a water-driven gas-storage power station transformed from an abandoned mine;

[0018] Among them, 1. Water tank; 2. Air tank; 3. Water pump; 4. Hydroelectric generator; 5. Reservoir; 6. Valve; 7. Liquid storage tank; 8. Power output equipment; 9. Power input equipment; 10. Water replenishment valve; 11. Liquid replenishment valve; 12. Connecting pipe. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] The purpose of the present invention is to provide a water-driven gas-fired energy storage power station transformed from an abandoned mine to solve the problems existing in the above-mentioned prior art. It combines the existing pumped-storage power station and gas energy storage, does not require the upper and lower reservoir conditions with the elevation difference required by the pumped-storage power station, and has an energy conversion efficiency far higher than that of gas energy storage. The construction cost and operation cost of the power station are low.

[0021] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] like Figure 1 As shown, the present invention provides a water-driven gas storage energy power station transformed from an abandoned mine, comprising a water reservoir 5, a water tank 1 and a gas tank 2, the underground space of the abandoned mine is divided into three chambers of the water reservoir 5, the water tank 1 and the gas tank 2, the gas tank 2 is filled with liquid carbon dioxide, and the gas tank 2 is connected to the water tank 1 through a connecting pipe 12; the water tank 1 and the water reservoir 5 are respectively connected with an inlet pipe and a return pipe, the inlet pipe is provided with a hydroelectric generator 4 and a valve 6, and the return pipe is provided with a water pump 3.

[0023] In one of the embodiments, photovoltaic power, wind power, and abandoned electricity during off-peak hours are used to pump water from the water reservoir 5 to the water tank 1, and the gas volume in the water tank 1 is reduced to increase the pressure of the gas in the gas tank 2, compressing the carbon dioxide gas in the gas tank 2 to convert the electrical energy into the internal energy of the gas molecules and store it.

[0024] In one of the embodiments, the gas chamber 2 is connected to a liquid storage tank 7 via a liquid replenishing pipe, and a liquid replenishing valve 11 is provided on the liquid storage tank 7.

[0025] In one embodiment, a saturated sodium bicarbonate solution is injected into the water tank 1 .

[0026] In one embodiment, the water reservoir 5 is an open water tank, and the water tank 1 and the air tank 2 are closed pressure chambers.

[0027] In one of the embodiments, a water replenishment pipeline is provided on the water reservoir 5 , and a water replenishment valve 10 is provided on the water replenishment pipeline, so that the water reservoir 5 is replenished with water through the water replenishment pipeline.

[0028] In one embodiment, the hydroelectric generator 4 is connected to an electric power output device 8 .

[0029] In one of the embodiments, the water pump 3 is connected to a power input device 9 .

[0030] The principle of the water-driven gas storage power station transformed from an abandoned mine is as follows:

[0031] A pumped-storage power station uses photovoltaic, wind power, and abandoned electricity from low electricity consumption periods to lift water from the lower reservoir to the upper reservoir, storing electricity in the form of water potential energy. When needed, the water from the upper reservoir is released to the lower reservoir to generate electricity, converting the potential energy of water into kinetic energy of water, and then into electrical energy to supply power to the grid.

[0032] The solution of our carbon dioxide energy storage warehouse (i.e., gas warehouse 2) is: use abandoned electricity to pump water to the carbon dioxide energy storage warehouse, compress the carbon dioxide gas in gas warehouse 2 and then convert the electrical energy into the internal energy of gas molecules for storage, and then when needed, drive hydroelectric power generation by pressure difference to convert the internal energy of gas into electrical energy, which plays the role of peak shaving and valley filling. In this way, there is no need for upper and lower reservoirs with height difference, avoiding the limitation of terrain conditions; both are air energy storage, but the storage efficiency is much higher than that of compressed air-based technology. The system efficiency of the present invention can reach 70%, which is equivalent to that of pumped storage power stations.

[0033] like Figure 1 , the underground space is partially blocked and anti-seepage treated to form three chambers: air chamber 2, water chamber 1, and water reservoir 5. Air chamber 2 and water chamber 1 are under pressure, water chamber 1 and water reservoir 5 need anti-seepage and necessary reinforcement, and equipment chamber can also be set up, and water reservoir 5 and equipment chamber need to be ventilated and open.

[0034] A certain amount of liquid carbon dioxide is filled into the gas tank 2, which gradually vaporizes by absorbing geothermal heat to form the required pressure, such as 4MPa (which can be determined according to the geological conditions of the balanced ground pressure. The higher the pressure, the greater the energy density), and the energy is stored therein for later use. A certain amount of saturated sodium bicarbonate solution (to reduce the dissolution of carbon dioxide in water and reduce operating consumption, hereinafter referred to as water) is injected into the water tank 1 for later use.

[0035] Description of the use process:

[0036] When power generation is required, valve 6 is opened, and the water in water tank 1 flows through hydroelectric generator 4 under the pressure difference between water tank 1 and water reservoir 5, and drives hydroelectric generator 4 to generate power and supply power to the grid. The water after power generation flows into water reservoir 5 for storage. After the power generation process is completed, valve 6 is closed to wait for the next power generation instruction.

[0037] Under the action of abandoned electricity, water pump 3 (plunger pump or multi-stage submersible pump) pressurizes the water in water reservoir 5 into water tank 1, and the gas volume in water tank 1 is reduced, while the gas in gas tank 2 is pressurized. This is the process of storing abandoned electricity in the internal energy of gas molecules. When power generation is needed, the hydroelectric generator 4 is started again. Water enters water reservoir 5 from water tank 1, and is then pressurized by water pump 3 and injected into water tank 1 to achieve recycling.

[0038] Carbon dioxide is dissolved in the water flowing out of the water tank 1 during the operation of the hydroelectric generator 4 , and is lost after being released into the water reservoir 5 . The lost part is replenished by the liquid storage tank 7 .

[0039] The process is intelligently controlled by the control system and runs fully automatically.

[0040] The energy conversion process is as follows: the process of pressurizing the water in the water reservoir 5 and injecting it into the water tank 1 through the water pump 3 is the process of transferring the electrical energy into the internal energy of the carbon dioxide gas and storing it in the gas tank 2, and then the hydroelectric generator 4 converts the internal energy into electrical energy and inputs it into the power grid. Different from compressed air energy storage, it utilizes the incompressible property of water, uses water as the medium for energy conversion, and utilizes mature hydroelectric power generation technology and equipment, avoiding the unavoidable low efficiency, high consumption, and difficult maintenance difficulties of air compressors compressing air and air turbines generating electricity.

[0041] The purpose of this project, built in an abandoned mine, is to: (1) construct sufficiently large low-pressure gas and liquid storage tanks at low cost; and (2) utilize geothermal energy to balance the energy required for the Carnot cycle and improve the energy conversion efficiency of the system.

[0042] Power generation and other parameters

[0043] According to a rough calculation based on 1 million cubic meters of gas storage space and 1.2 million cubic meters of water storage, a pressure of 4 MPa is required, which requires an initial injection of about 70,000 tons (including dissolved water loss) of liquid carbon dioxide. Direct injection, without energy supply, forms the initial energy accumulation by absorbing geothermal heat for natural gasification (the energy required for gasification is estimated to be 2*10 13 joules, provided by geothermal heat, with no additional energy required).

[0044] The 200,000 tons of water in the water tank 1 flows to the open water tank 5 under the pressure of 4 MPa, and the electricity generated is 7*10 11 Joule, equivalent to 200,000 kilowatt-hours of electricity, is equivalent to releasing 200,000 tons of water with the potential energy of 400 meters above sea level.

[0045] That is, the expected indicators of the power station:

[0046] The hydroelectric generating set with a generating capacity of 100MW can generate electricity continuously for 2 hours, and generate electricity for 2 hours during the peak period of electricity consumption every day, contributing 200,000 kWh of peak electricity every day.

[0047] The configuration of hydroelectric generator sets and water pump sets can refer to pumped storage power stations.

[0048] If the air compressor solution is adopted, the efficiency of the air compressor is only about 15%, the total conversion efficiency is less than 12%, and the maintenance cost is high. The generated heat energy must be reused. Obviously, the carbon dioxide solution is far superior to the air compressor solution. The use of carbon dioxide is in line with the dual carbon policy.

[0049] Carbon dioxide is slightly soluble in water, with a solubility of 0.14g / 100g water at room temperature and pressure. The solubility increases under high pressure, so the loss is huge. Measures must be taken to use saturated sodium bicarbonate solution instead of clean water to significantly reduce the loss of carbon dioxide dissolution. If nitrogen is used as the energy storage medium, clean water can be used directly.

[0050] Saturated sodium bicarbonate solution is low-cost, non-toxic and harmless and can be used.

[0051] The water-driven gas-storage energy-saving power station transformed from an abandoned mine of the present invention has the following advantages:

[0052] 1. The carbon dioxide used is cheap, readily available, safe, and in line with the dual carbon policy.

[0053] 2. The system is placed underground, and its operation is safe and reliable. It does not occupy ground resources and does not harm the environment. By using abandoned mines, the construction investment is greatly reduced. By using geothermal energy, the energy required for the Carnot cycle is balanced, and the energy conversion efficiency of the system is improved.

[0054] 3. Abandoned mines can be used as pressure gas and liquid storage to improve the ground pressure imbalance caused by mining. Otherwise, abandoned mines generally need to be backfilled to prevent collapse and cause geological disasters, and the backfilling cost is huge.

[0055] 4. Water and carbon dioxide are recycled, a physical process with low consumption and high efficiency. The whole process is carried out at room temperature, without temperature stress damage, heat loss, etc.

[0056] 5. The main equipment that consumes electricity in energy conversion is the water pump 3. Usually, the efficiency of the water pump 3 is 85% to 95%. It is driven by abandoned electricity, and the consumed electricity is stored in the gas in the gas tank 2.

[0057] 6. Its scale depends on the total volume of available underground chambers and tunnels, which can be very large. The energy density can also be increased by increasing the system's pressure resistance.

[0058] 7. Abandoned electricity is used to replenish water and energy without time restrictions. It can be used whenever it is available. Power generation is also output on demand. The system has high capacity. Power generation and abandoned electricity replenishment can be done simultaneously or sequentially, as long as the overall balance is achieved, without time, climate and other restrictions.

[0059] 8. Gas chamber 2 is large enough, pressure fluctuation is small, power generation quality is good and power generation is stable.

[0060] It should be noted that it is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention, and any figure mark in the claims should not be regarded as limiting the claims involved.

[0061] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A water-driven gas-storage energy power station transformed from an abandoned mine, characterized by: It includes a water reservoir, a water tank and an air tank, dividing the underground space of the abandoned mine into three chambers, the water reservoir, the water tank and the air tank, the air tank is filled with liquid carbon dioxide, and the air tank is connected to the water tank through a connecting pipe; the water tank and the water reservoir are respectively connected with an inlet pipe and a return pipe, the inlet pipe is provided with a hydraulic generator and a valve, and the return pipe is provided with a water pump.

2. The water-driven gas energy storage power station transformed from an abandoned mine according to claim 1 is characterized by: Photovoltaic power, wind power, and abandoned electricity during off-peak hours are used to pump water from the water reservoir to the water tank. The gas volume in the water tank is reduced, the gas in the tank is pressurized, and the carbon dioxide gas in the tank is compressed to convert the electrical energy into the internal energy of gas molecules for storage.

3. The water-driven gas-storage energy-saving power station transformed from an abandoned mine according to claim 1 is characterized in that: The gas chamber is connected to a liquid storage tank via a liquid replenishing pipe, and a liquid replenishing valve is arranged on the liquid storage tank.

4. The water-driven gas-storage energy-saving power station transformed from an abandoned mine according to claim 1 is characterized in that: The water tank is injected with a saturated sodium bicarbonate solution.

5. The water-driven gas-storage energy-saving power station transformed from an abandoned mine according to claim 1 is characterized in that: The water reservoir is an open water tank, and the water tank and the air tank are closed pressure-bearing chambers.

6. The water-driven gas-storage energy power station transformed from an abandoned mine according to claim 1 is characterized by: The water reservoir is provided with a water replenishment pipeline, and a water replenishment valve is provided on the water replenishment pipeline, and the water reservoir is replenished with water through the water replenishment pipeline.

7. The water-driven gas-storage energy-saving power station transformed from an abandoned mine according to claim 1 is characterized in that: A drainage pipe is arranged at the bottom of the gas bin.

8. The water-driven gas-storage energy power station transformed from an abandoned mine according to claim 1 is characterized by: The hydroelectric generator is connected to an electric power output device.

9. The water-driven gas-storage energy power station transformed from an abandoned mine according to claim 1, characterized in that: The water pump is connected to the power input device.

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