Energy storage system for converting compressed air into electric power

Abstract

The invention relates to an energy storage system for converting compressed air into electric power in the technical field of electric power storage, which comprises a compressor unit, an air storage tank and an expansion unit, a first valve and a second valve are respectively mounted on pipe sections, close to the air storage tank, of the air compression pipe and the air expansion pipe; a piston plate dividing an inner cavity of the air storage tank into an upper cavity and a lower cavity is arranged in the air storage tank, the piston plate is in sliding seal with the inner wall of the air storage tank and can vertically slide, the air compression pipe and the air expansion pipe are correspondingly communicated with the lower cavity, a drainage pipe is arranged at the lowest position of the bottom of the lower cavity, and a drain valve is installed at the outer end of the drainage pipe. A distribution pipe is arranged on one side of the air compression pipe, a plurality of small blowing pipes corresponding to the corresponding middle sections of the air compression pipe are arranged on a pipe body of the distribution pipe, the distribution pipe is correspondingly communicated with the top of the upper cavity through an airflow pipe, and a first adjusting valve is installed on the airflow pipe; the energy storage system can reduce the cost and improve the gas storage efficiency and the pressure release stability.

Description

Technical Field

[0001] The present invention relates to the technical field of power storage, and in particular to an energy storage system that converts electricity using compressed air. Background Art

[0002] As is known, compressed air energy storage is a technology that converts electrical energy into compressed air and stores it. Its basic principle is to use electricity to drive an air compressor to compress and store air in underground cavities or high-pressure containers. When energy needs to be released, the stored compressed air is converted into electrical energy through an expander or a turbine. For example, the Chinese invention patent with the announcement number CN115853613A uses this technical principle to disclose a compressed air energy storage system, but it has three defects: first, since air releases heat when it is compressed, in order to prevent the temperature between factories, it adds a cooler to cool the pipeline, which increases the equipment cost; second, it also provides a drying and filtering device on the compressed air intake pipeline to filter the moisture in the air, but after the air entering the compressed air storage tank is compressed, it is inevitable that water droplets will be generated under high pressure. If it is not cleaned for a long time, the use efficiency of the air storage tank will be greatly reduced; third, when the compressed air is released from the storage tank, it is only adjusted by a regulating valve. When the pressure becomes smaller in the second half of the release, it will still cause pressure instability. Summary of the invention

[0003] In order to overcome the deficiencies in the background technology and solve the existing technical problems, the present invention discloses an energy storage system that uses compressed air to convert electricity, which can reduce costs and improve gas storage efficiency and pressure release stability.

[0004] To achieve the above object, the present invention adopts the following technical solutions: A energy storage system that uses compressed air to convert electricity comprises a compressor unit, an air storage tank and an expansion unit, wherein the air storage tank is connected to the compressor unit and the expansion unit respectively through an air compression pipe and an air expansion pipe, and the pipe sections of the air compression pipe and the air expansion pipe close to the air storage tank are respectively installed with a first valve and a second valve; the air storage tank is provided with a piston plate that divides the inner cavity of the air storage tank into an upper cavity and a lower cavity, the edge of the piston plate is slidably sealed with the inner wall of the air storage tank and can slide vertically, the air compression pipe and the air expansion pipe are respectively connected to the lower cavity, a drain pipe is provided at the lowest position of the bottom of the lower cavity, and a drain valve is installed at the outer end of the drain pipe; a distribution pipe is provided on one side of the air compression pipe, and the pipe body of the distribution pipe is provided with a plurality of small blowing tubes corresponding to the corresponding middle sections of the air compression pipe, the distribution pipe is connected to the top of the upper cavity through an air flow pipe, and a first regulating valve is installed on the air flow pipe.

[0005] Furthermore, the middle section of the air compressor pipe is bent to form a serpentine pipe section, and a plurality of small air blowing pipes are evenly spaced along the axial direction of the distribution pipe.

[0006] Furthermore, a conduction pipe with a third valve is provided on the top of the upper cavity, and a first filter is connected to the outer end of the air inlet pipe.

[0007] Furthermore, the gas storage tank is a vertical tank, the top of the gas storage tank is provided with a positioning ring corresponding to the outer edge of the upper plate surface of the piston plate, the outer side wall of the piston plate is provided with a sealing ring, and the outer edge of the lower plate surface of the piston plate is fixed with a wiper ring.

[0008] Furthermore, a vertical guide tube is provided in the center of the gas storage tank, and a central hole is provided in the center of the piston plate surface to cooperate with the guide tube in a sliding and sealing manner.

[0009] Furthermore, a fixed limiting cover is provided above the lowest position of the bottom of the lower cavity of the gas storage tank, the lower end of the guide tube is fixed to the top of the limiting cover, and a water flow gap is provided on the cover wall of the limiting cover.

[0010] Furthermore, the air pressure pipe is provided with a one-way valve for conducting air intake to the air storage tank.

[0011] Furthermore, a second filter is installed at the air inlet of the compressor unit.

[0012] Furthermore, the air expansion pipe is equipped with a second regulating valve.

[0013] Due to the adoption of the above-mentioned technical solution, the present invention has the following beneficial effects: The energy storage system using compressed air to convert electricity disclosed by the present invention provides a piston plate in the gas storage tank, so that when the air pressure tube is compressed, released heat and inflated, it can drive the piston plate to move upward, and then the air in the upper cavity of the gas storage tank can be blown out from the small blowing tube, the air pressure tube is cooled by air, and the heat dissipation efficiency of air flow is improved. When the air expansion tube releases the air pressure, the piston plate moves downward, which can not only scrape off the water droplets attached to the wall of the gas storage tank and discharge them from the drain valve, but also as the piston plate is pressed downward by gravity, the volume of the lower cavity becomes smaller, even if the air pressure also becomes smaller, the stability of the released pressure can be further maintained, thereby ensuring the stability of power generation of the expansion unit. In summary, compared with the prior art, the present invention can not only greatly reduce the equipment cost, but also promote the discharge of water in the gas storage tank, improve the gas storage efficiency and, at the same time, further ensure the stability of air pressure release. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the implementation structure of the present invention; Figure 2 It is a schematic diagram of the cross-sectional structure of the gas storage tank.

[0015] In the figure: 1. compressor unit; 2. air compressor pipe; 3. expansion unit; 4. second regulating valve; 5. second valve; 6. steam trap; 7. air storage tank; 8. piston plate; 9. first filter; 10. third valve; 11. first regulating valve; 12. distribution pipe; 13. small air blowing tube; 14. second filter; 15. first valve; 16. one-way valve; 17. wiper ring; 18. positioning ring; 19. guide pipe; 20. limit cover; 21. air expansion pipe. DETAILED DESCRIPTION

[0016] The technical solution of the present invention will be described below in conjunction with the drawings in the embodiments of the present invention. In the description, it should be understood that if there are terms such as "upper", "lower", "front", "back", "left", "right", etc. indicating directions or positional relationships, they only correspond to the drawings of the present invention and are for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific direction. Embodiment 1:

[0017] Combined with Figure 1 The energy storage system for converting compressed air into electricity comprises a compressor unit 1, an air storage tank 7 and an expansion unit 3. The air storage tank 7 is connected to the compressor unit 1 and the expansion unit 3 through an air compression pipe 2 and an air expansion pipe 21, respectively. The air compression pipe 2 and the air expansion pipe 21 are respectively installed with a first valve 15 and a second valve 5 at the pipe sections close to the air storage tank 7. When electricity is converted into compressed air for storage, the second valve 5 needs to be closed and the first valve 15 needs to be opened. Then, the compressor unit 1 is driven by electricity to work, and the generated compressed air is stored in the air storage tank 7 from the air compression pipe 2. When the compressed air needs to be converted into electricity, the first valve 15 needs to be closed and the second valve 5 needs to be opened. Then, the air released from the air expansion pipe 21 drives the expansion unit 3 to work and generate electricity. According to needs, the air compression pipe 2 is installed with a one-way valve 16 that is connected to the air intake of the air storage tank 7 to prevent the compressed air in the air storage tank 7 from flowing back. The air expansion pipe 21 is installed with a second regulating valve 4 to ensure the stability of pressure release. In addition, a second filter 14 is installed at the air inlet of the compressor unit 1 to ensure that the compressed air entering is relatively clean. The gas tank 7 is provided with a piston plate 8 which divides the inner cavity of the gas tank 7 into an upper cavity and a lower cavity. The piston plate 8 has a counterweight so that it can automatically move downward when the pressure in the lower cavity decreases. The edge of the piston plate 8 is slidably sealed with the inner wall of the gas tank 7 and can slide vertically to ensure the sealing of the piston plate 8 during its movement. The air pressure pipe 2 and the air expansion pipe 21 are respectively connected to the lower cavity. A drain pipe is provided at the lowest position of the bottom of the lower cavity. A drain valve 6 is installed at the outer end of the drain pipe. When water droplets condense in the lower cavity due to high pressure, they can be discharged through the drain valve 6 to prevent excessive water accumulation and affect the use efficiency of the gas tank 7. A distribution pipe 12 is provided on one side of the air compressor pipe 2. The pipe body of the distribution pipe 12 is provided with a plurality of small blowing tubes 13 corresponding to the corresponding middle sections of the air compressor pipe 2. The distribution pipe 12 is connected to the top of the upper cavity through the air flow pipe. A first regulating valve 11 is installed on the air flow pipe. When the air compressor pipe 2 is in a state of compressed air exothermic inflation, it can drive the piston plate 8 to move upward, so that the air in the upper cavity of the air storage tank 7 can be blown out from the small blowing tube 13, and the air compressor pipe 2 is air-cooled to improve the heat dissipation efficiency of air flow; as needed, the middle section of the air compressor pipe 2 is bent to form a serpentine pipe section, and a plurality of small blowing tubes 13 are evenly spaced along the axial direction of the distribution pipe 12 to further improve the heat dissipation efficiency; when the pressure in the lower cavity is released, in order to ensure that the piston plate 8 naturally descends by gravity, it is necessary to ensure that the upper cavity does not generate negative pressure, so it is necessary to open the first regulating valve 11 for air intake. Of course, a conducting pipe with a third valve 10 can also be provided at the top of the upper cavity, which is specifically used for balancing the air intake. At the same time, a first filter 9 is connected to the outer end of the intake pipe to ensure clean air intake.

[0018] In the energy storage system for converting electricity using compressed air of the present invention, when the second valve 5 and the third valve 10 are closed, the first valve 15 is opened, and the compressor unit 1 is started to compress air, the air pressure pipe 2 enters the state of air compression, heat release and inflation, which can drive the piston plate 8 to move upward, so that the air in the upper cavity of the gas storage tank 7 can be blown out from the small blowing tube 13 under the regulation of the first regulating valve 11, and the air pressure pipe 2 is air-cooled to improve the air flow and heat dissipation efficiency; and when the first valve 15 is closed, the second valve 5 and the third valve 10 are opened to convert compressed air into electrical energy, the air expansion pipe 21 releases the air pressure in the lower cavity, and the piston plate 8 moves downward, which can not only scrape off the water droplets attached to the tank wall of the gas storage tank 7 and discharge them from the steam trap 6, but also as the piston plate 8 is pressed downward by gravity, even if the air pressure decreases, the volume of the lower cavity will also decrease accordingly, further maintaining the stability of the released pressure, thereby ensuring the stability of power generation by the expansion unit 3. Embodiment 2:

[0019] As attached Figure 2As shown, on the basis of the first embodiment, the gas storage tank 7 is designed to be a vertical tank, and a positioning ring 18 corresponding to the outer edge of the upper plate surface of the piston plate 8 is provided at the top of the gas storage tank 7, and a sealing ring is provided on the outer wall of the piston plate 8. The sealing ring itself can maintain good sealing with the tank wall of the gas storage tank 7. When the piston plate 8 moves upward to contact the positioning ring 18, it can not only be positioned, but also can use the positioning ring 18 to squeeze the sealing ring, further improving the air tightness, which is conducive to long-term gas storage. A wiper ring 17 is fixed to the outer edge of the lower plate surface of the piston plate 8 to scrape off water droplets attached to the tank wall of the gas storage tank 7; as needed, a vertical guide tube 19 is provided in the center of the gas storage tank 7, and a central hole that cooperates with the guide tube 19 for sliding sealing is provided in the center of the plate surface of the piston plate 8 to ensure that the piston plate 8 can move up and down flexibly and prevent it from getting stuck; in addition, a fixed limit cover 20 is provided above the lowest position of the bottom of the lower cavity of the gas storage tank 7, and the lower end of the guide tube 19 is fixed to the top of the limit cover 20, and the cover wall of the limit cover 20 is provided with a water flow gap to facilitate the collection and discharge of collected water.

[0020] The parts of the present invention that are not described in detail are prior art. It is obvious to those skilled in the art that the present invention is not limited to the details of the above-mentioned exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, no matter from which point of view, the above-mentioned embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is limited by the attached claims rather than the above description. Therefore, it is intended to include all changes within the meaning and scope of the equivalent elements of the claims in the present invention, and any figure marks in the claims should not be regarded as limiting the content of the claims involved.

Claims

1. An energy storage system for converting compressed air into electricity, comprising a compressor unit (1), an air storage tank (7) and an expansion unit (3), wherein the air storage tank (7) is connected to the compressor unit (1) and the expansion unit (3) via an air compression pipe (2) and an air expansion pipe (21), respectively, and the pipe sections of the air compression pipe (2) and the air expansion pipe (21) close to the air storage tank (7) are respectively installed with a first valve (15) and a second valve (5), wherein: The air storage tank (7) is provided with a piston plate (8) for dividing the inner cavity of the air storage tank (7) into an upper cavity and a lower cavity. The edge of the piston plate (8) is slidably sealed with the inner wall of the air storage tank (7) and can slide vertically. The air pressure pipe (2) and the air expansion pipe (21) are respectively connected to the lower cavity. A drainage pipe is provided at the lowest position of the bottom of the lower cavity. A drain valve (6) is installed at the outer end of the drainage pipe. A distribution pipe (12) is provided on one side of the air pressure pipe (2). The pipe body of the distribution pipe (12) is provided with a plurality of small air blowing pipes (13) corresponding to the corresponding middle sections of the air pressure pipe (2). The distribution pipe (12) is connected to the top of the upper cavity through an air flow pipe. A first regulating valve (11) is installed on the air flow pipe.

2. The energy storage system for converting electricity using compressed air according to claim 1, characterized in that: The middle section of the air compression pipe (2) is bent to form a serpentine pipe section, and a plurality of small air blowing pipes (13) are evenly spaced along the axial direction of the distribution pipe (12).

3. The energy storage system for converting electricity using compressed air according to claim 1, characterized in that: A conduction pipe with a third valve (10) is provided at the top of the upper cavity, and a first filter (9) is connected to the outer end of the air intake pipe.

4. The energy storage system for converting electricity using compressed air according to claim 1, characterized in that: The gas storage tank (7) is a vertical tank. A positioning ring (18) corresponding to the outer edge of the upper plate surface of the piston plate (8) is provided at the top of the gas storage tank (7). A sealing ring is provided on the outer wall of the piston plate (8). A wiper ring (17) is fixed to the outer edge of the lower plate surface of the piston plate (8).

5. The energy storage system for converting electricity using compressed air according to claim 4 is characterized in that: A vertical guide tube (19) is provided in the center of the gas storage tank (7), and a central hole is provided in the center of the piston plate (8) surface for sliding and sealing cooperation with the guide tube (19).

6. The energy storage system for converting electricity using compressed air according to claim 5 is characterized in that: A fixed limit cover (20) is provided above the lowest position of the bottom of the lower cavity of the gas storage tank (7), the lower end of the guide tube (19) is fixed to the top of the limit cover (20), and a water flow notch is provided on the cover wall of the limit cover (20).

7. The energy storage system for converting electricity using compressed air according to claim 1, characterized in that: The air pressure pipe (2) is provided with a one-way valve (16) for conducting air intake to the air storage tank (7).

8. The energy storage system for converting electricity using compressed air according to claim 1, characterized in that: A second filter (14) is installed at the air inlet of the compressor unit (1).

9. The energy storage system for converting electricity using compressed air according to claim 1, characterized in that: The air expansion pipe (21) is installed with a second regulating valve (4).

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