Novel water pumping type compressed air energy storage system

Abstract

The invention relates to a novel water pumping type compressed air energy storage system, which belongs to the technical field of energy storage, and can store energy by compressing air by using a compressor and increasing the water level in the heat storage and exchange circulation of an original water path in the off-peak period of the load of a power grid by directly optimizing and innovating the process flow of the water path circulation of a conventional compressed air energy storage system. Compressed air and potential energy in water path heat storage and exchange circulation are released in the power grid load peak period to drive an expansion machine and a water turbine to drive a generator to generate electricity. The system comprises a compressor unit, a heat regenerator, an expansion unit, a reheater, an overground heat / cold water storage tank, an underground cold / hot water chamber, an underground air storage chamber, a water turbine, a power generation system and other key components. The system provided by the invention can realize efficient energy storage and release, and is suitable for a large-scale long-time physical energy storage solution.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage, and particularly relates to a new type of pumped compressed air energy storage system. Background Art

[0002] In recent years, there has been an urgent need for energy storage technologies in aspects such as power grid peak shaving, improving power grid reliability, and enhancing power quality. According to different energy storage forms, energy storage technologies are divided into pumped storage, compressed air energy storage, battery energy storage, superconducting energy storage, flywheel energy storage, supercapacitor, etc. Among them, compressed air energy storage has advantages such as large scale, low construction cost, and long lifespan. Using air as the energy storage medium, it realizes the storage and management of electric energy through the mutual conversion between electric energy and the internal energy of high-pressure and low-temperature air, and is one of the most promising large-scale energy storage technologies above 100 MW. Currently, it has entered the commercial application stage. However, the construction of compressed air energy storage also requires large compressors, expanders, and large gas storage caves, etc. The system has a large number of mechanical components, great control difficulty, and a long deployment and construction period. Summary of the Invention

[0003] Aiming at the above problems, the purpose of the present invention is to provide a new type of pumped compressed air energy storage system, aiming to improve the energy conversion efficiency while reducing the system cost. This system combines compressed air energy storage and underground pumped storage technologies.

[0004] To achieve the above purpose, the present invention adopts the following technical solutions: A new type of pumped compressed air energy storage system, including a motor set, a generator set, a gas pipeline, and a circulating water pipeline: A compressor set, a regenerator, a gas storage chamber, a reheater, and an expander set arranged in sequence on the gas pipeline; A cold water chamber, a regenerator, a hot water chamber, and a reheater arranged in sequence on the circulating water pipeline; Among them, the built-in gas path of the gas pipeline connects the regenerator and the reheater, and the built-in water path of the circulating water pipeline connects the regenerator and the reheater; Among them, the motor set supplies power to the compressor set; Among them, the water turbine is at a low position, and the expander set is used to drive the generator set to generate electricity; Among them, the regenerator and the reheater are located on the ground.

[0005] As a further preferred solution, the cold water chamber and the gas storage chamber are located deep underground and are lower than the hot water chamber; A water pump is provided on the circulating water pipeline between the cold water chamber and the regenerator, and the motor set supplies power to the water pump; a water turbine is provided on the circulating water pipeline between the reheater and the cold water chamber, and the water turbine is used to drive the generator set to work; The water turbine is located underground and is higher than the cold water chamber.

[0006] As a further preferred solution, the hot water chamber is above ground.

[0007] As a further preferred solution, the hot water chamber is located on the ground surface, and the hot water chamber is a ground surface hot water pool, which is a closable pool on the ground or an artificial chamber in the shallow surface layer.

[0008] As a further preferred solution, the hot water chamber and the gas storage chamber are located deep underground and are lower than the cold water chamber; A high-pressure pipeline is provided between the hot water chamber and the gas storage chamber, and a water turbine is provided between the regenerator and the hot water chamber. The water turbine is used for power generation and drives the generator set to work; The water turbine is located underground and is higher than the hot water chamber.

[0009] As a further preferred solution, the cold water chamber is above ground.

[0010] As a further preferred solution, the cold water chamber is located on the ground surface, and the cold water chamber is a ground surface hot water pool, which is a closable pool on the ground or an artificial chamber in the shallow surface layer.

[0011] As a further preferred solution, a through air path is provided between the hot water chamber and the cold water chamber. Beneficial effects

[0012] The system of the present invention can achieve efficient energy storage and release, can flexibly adjust the capacity and proportion of compressed air energy storage and embedded pumped-storage energy according to requirements, fully combines the advantages of compressed air energy storage and pumped-storage energy, better responds to the energy storage regulation mechanism and the utilization of peak-valley electricity, and is applicable to large-scale long-term physical energy storage solutions. Description of the drawings

[0013] Figure 1 It is a schematic structural diagram of Embodiment 1; Figure 2 It is a schematic structural diagram of Embodiment 2; Figure 3 It is a schematic structural diagram of Embodiment 3; Figure 4 It is a schematic structural diagram of Embodiment 4; In the figure: 1 - motor set; 2 - compressor set; 3 - expander set; 4 - generator set; 5 - regenerator; 6 - reheater; 7 - hot water chamber; 8 - water pump; 9 - water turbine; 10 - cold water chamber; 11 - gas storage chamber; 12 - through air path; 13 - high-pressure pipe; 14 - solenoid valve. Specific embodiments

[0014] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Embodiment 1

[0015] As Figure 1 , a pumping-type new compressed air energy storage system described in this embodiment includes a motor set 1, a generator set 4, a gas pipeline, and a circulating water pipeline: A compressor set 2, a regenerator 5, a gas storage chamber 11, a reheater 6, and an expansion unit 3 are arranged in sequence on the gas pipeline; A cold water chamber 10, a regenerator 5, a hot water chamber 7, and a reheater 6 are arranged in sequence on the circulating water pipeline; The gas pipeline is connected to the built-in gas path of the regenerator 5 and the reheater 6, and the circulating water pipeline is connected to the built-in water path of the regenerator 5 and the reheater 6; The motor set 1 supplies power to the compressor set 2; the water turbine 9 is at a low position, and the expansion unit 3 is used to drive the generator set 4 to output electric energy by doing work; The compressor set 2, the regenerator 5, the gas storage chamber 11, the reheater 6, and the expansion unit 3 are located on the ground.

[0016] In Embodiments 1 and 2, the cold water chamber 10 and the gas storage chamber 11 are located deep underground and are lower than the hot water chamber 7; A water pump 8 is provided on the circulating water pipeline between the cold water chamber 10 and the regenerator 5, and the motor set 1 supplies power to the water pump 8; a water turbine 9 is provided on the circulating water pipeline between the reheater 6 and the cold water chamber 10, and the water turbine 9 is used for generating electricity and driving the generator set 4 to work; The water turbine 9 is located underground and is higher than the cold water chamber 10.

[0017] Taking Embodiment 1 as an example, the working principle of the pumping-type new compressed air energy storage system for realizing electric energy storage and release is described: During the electric energy storage process, the motor set 1 supplies power to the compressor set 2 and the water pump 8 respectively, and the gas cycle and the water cycle start to operate. The outside air is filtered and then enters the inside of the compressor set 2 for multi-stage compression. At the outlet of each stage of the compressor, heat exchange is completed with the cold water in the water cycle through the regenerator 5, and then enters the inlet of the next stage of the compressor. Finally, the compressed high-pressure air enters the ground through the pipeline and is stored in the gas storage chamber 11; In the water cycle, after the water pump 8 starts to work, the cold water in the cold water chamber 10 is pumped into the regenerator 5 through the water pump 8, exchanges heat with the compressed air at the inter-stage, and then enters the hot water chamber 7, storing the compression heat in the form of the internal energy of water. When the gas storage chamber 11 reaches the required pressure, the energy storage process ends. During this process, the motor set 1 supplies power to the compressor set 2 and the water pump 8 to provide drive at the same time. A part of the electric energy is stored as the internal energy of air and water through the multi-stage compression of the compressor set 2, and a part of the electric energy is stored as the potential energy of water by the pumping work of the water pump 8 to lift the water in the cold water chamber 10 to the hot water chamber 7.

[0018] During the electric energy release process, the high-pressure air stored in the gas storage chamber 11 enters the reheater 6 through the pipeline and is heated up. Subsequently, it enters the expansion unit 3 through the gas pipeline for multi-stage expansion and inter-stage heat exchange, and finally is discharged into the atmospheric environment through the outlet of the last-stage expander. In the water cycle, the hot water in the hot water chamber 7 enters the reheater 6 to heat the compressed air, and then enters the cold water chamber 10 through the water pipeline, and uses the potential energy to drive the water turbine 9 to do work. When the pressure in the gas storage chamber 11 drops to a certain level, the energy release process ends. The internal energy of the air in the gas storage chamber 11 and the internal energy of the water in the hot water chamber 7 do work through the expander and drive the generator set 4 to generate electricity, which becomes electric energy and is output externally. The water in the hot water chamber 7 reaches the cold water chamber 10 through the water pipeline, and uses the conversion of the gravitational potential energy of the water to drive the water turbine and drive the generator set 4 to generate electricity. Embodiment 2

[0019] Refer to Figure 2 , which is the second embodiment of the present invention. Different from Embodiment 1, in this embodiment, the surface hot water chamber (pool) is used to replace the hot water chamber 7. The surface hot water chamber (pool) is an enclosed pool on the ground or a chamber in the shallow surface layer, which is used to store high-temperature hot water.

[0020] In Embodiment 1 and Embodiment 2, the water in the hot water tank 7 is driven to the cold water chamber 10 by the water pump in the original system. Embodiment 3

[0021] Refer to Figure 3 , which is the third embodiment of the present invention. Different from Embodiment 1, in this embodiment, the original hot water chamber 7 is used to store cold water, which is replaced by the cold water chamber 10, and the original cold water chamber 10 is used to store hot water, which is replaced by the hot water chamber 7; as an optimization of the energy storage system process, during the energy release process, the high-pressure air in the gas storage chamber 11 can directly drive the hot water in the hot water chamber 7 to rise to the ground and enter the reheater 6 to heat the compressed air, and then be stored in the cold water chamber 10 on the ground, and the water pump 8 is cancelled.

[0022] That is, the hot water chamber 7 and the gas storage chamber 11 are located deep underground and are lower than the cold water chamber 10; A high-pressure pipeline 13 is provided between the hot water chamber 7 and the gas storage chamber 11, and a water turbine 9 is provided between the regenerator 5 and the hot water chamber 7. The water turbine 9 is used to drive the generator set 4 to work; The water turbine 9 is located underground and is higher than the hot water chamber 7. Embodiment 4

[0023] Refer to Figure 4 , which is the fourth embodiment of the present invention. Different from Embodiment 3, in this embodiment, the surface cold water chamber (pool) is used to replace the cold water chamber 10. The surface cold water chamber (pool) is an enclosed pool on the ground or an artificial chamber in the shallow surface layer, which is used to store cold water.

[0024] In Embodiment 3 and Embodiment 4, the water in the cold water chamber 10 is driven to the hot water tank 7 by a water pump.

[0025] In Embodiment 3 and Embodiment 4, the through air passage 12 is for balancing air pressure. To avoid affecting the water in the hot water tank 7 from passing through the reheater 6 to the cold water chamber 10, a solenoid valve 14 is provided on the through air passage 12.

[0026] Taking a hundred-megawatt compressed air energy storage system as an example, assuming that the water consumption for heat storage and heat exchange is 100,000 cubic meters and the depth of the underground artificial chamber is 100 meters, then by using the pumped new type compressed air energy storage system of the present invention, about 20 MWh of additional electricity can be generated daily. Calculated at a peak-valley electricity price difference of 0.5 yuan, about 3 million yuan of additional income can be created annually.

[0027] As described above, only the preferred specific embodiments of the present invention are provided, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and all should be covered within the protection scope of the present invention.

Claims

1. A new type of pumped compressed air energy storage system, characterized in that: It includes an electric motor unit (1), a generator unit (4), a gas pipeline, and a circulating water pipeline: A compressor unit (2), a regenerator (5), an air storage chamber (11), a reheater (6), and an expansion unit (3) are sequentially arranged on the gas pipeline; A cold water chamber (10), a regenerator (5), a hot water chamber (7), and a reheater (6) are sequentially arranged on the circulating water pipeline; The gas pipeline is connected to the built-in gas pipelines of the regenerator (5) and the reheater (6), and the circulating water pipeline is connected to the built-in water pipelines of the regenerator (5) and the reheater (6); The motor unit (1) supplies power to the compressor unit (2); The water turbine (9) is located at a lower position, and the expansion unit (3) is used to drive the generator set (4) to generate electricity; The recuperator (5) and the reheater (6) are located on the ground.

2. A novel pumped compressed air energy storage system according to claim 1, characterized in that: The cold water chamber (10) and the air storage chamber (11) are located deep underground and lower than the hot water chamber (7); A water pump (8) is provided on the circulating water pipeline between the cold water chamber (10) and the reheater (5), and the motor unit (1) supplies power to the water pump (8); a water turbine (9) is provided on the circulating water pipeline between the reheater (6) and the cold water chamber (10), and the water turbine (9) is used to generate electricity and drive the generator unit (4) to work; The water turbine (9) is located underground and is higher than the cold water chamber (10).

3. A novel pumped compressed air energy storage system according to claim 2, characterized in that: The hot water chamber (7) is located on the ground.

4. A novel pumped compressed air energy storage system according to claim 2, characterized in that: The hot water chamber (7) is located on the ground surface. The hot water chamber (7) is a surface hot water pool. The surface hot water pool is a water pool that can be closed on the ground or an artificial chamber in the shallow surface layer.

5. A novel pumped compressed air energy storage system according to claim 1, characterized in that: The hot water chamber (7) and the air storage chamber (11) are located deep underground and lower than the cold water chamber (10); A high-pressure pipeline (13) is provided between the hot water chamber (7) and the gas storage chamber (11), and a water turbine (9) is provided between the heat regenerator (5) and the hot water chamber (7), and the water turbine (9) drives the generator set (4) to work; The water turbine (9) is located underground and higher than the hot water chamber (7).

6. A novel pumped compressed air energy storage system according to claim 5, characterized in that: The cold water chamber (10) is located on the ground.

7. A novel pumped compressed air energy storage system according to claim 5, characterized in that: The cold water chamber (10) is located on the ground surface. The cold water chamber (10) is a surface hot water pool. The surface hot water pool is a water pool that can be closed on the ground or an artificial chamber in the shallow surface layer.

8. A novel pumped compressed air energy storage system according to claim 2 or 5, characterized in that: A through air path (12) is provided between the hot water chamber (7) and the cold water chamber (10).

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