Multi-stage heat energy recovery gravity compressed air energy storage system

Abstract

The multi-stage type heat energy recovery gravity compressed air energy storage system comprises a water storage pool and at least two air storage cavities, the bottom of the water storage pool communicates with the bottom of each air storage cavity through a liquid pipeline, and the tops of the air storage cavities are connected with an air main pipe; the gas main pipe is connected with a compressor unit and a generator unit through branch pipes, heat exchange liquid is arranged in the reservoir, a heat exchange pipe is arranged at the bottom of the reservoir and extends out of the reservoir to be connected with a heat exchanger, and the heat exchanger is connected with an external heat storage device or a heat utilization facility. The gravity block and the heat exchange liquid are adopted to provide a high-pressure environment for compressed air in multiple aspects, the gravity block can conduct composite energy storage, and the energy storage efficiency is improved; and meanwhile, the heat exchange liquid can exchange heat with the compressed air, the stored heat of the compressed air is recycled, the temperature of the stored compressed air can be reduced, the compressed air is easier to store, and the storage efficiency is improved.

Description

Technical Field

[0001] The invention relates to a multi-stage heat energy recovery gravity compressed air energy storage system, belonging to the technical field of energy storage equipment. Background Art

[0002] Compressed air energy storage refers to a storage method that uses electrical energy to compress air during the low load period of the power grid, and releases compressed air to drive the steam turbine to generate electricity during the peak load period of the power grid. As an efficient and sustainable energy storage method, compressed air energy storage is gradually becoming the focus of people's attention.

[0003] In the prior art, the traditional compressed air energy storage system is simple in design and usually consists of three parts: a gas storage well, an air compressor unit, and an expansion generator unit. The gas compression process will increase the temperature and release heat. Although the existing compressed air energy storage system will be equipped with a heat exchanger for heat recovery, it will still cause heat energy waste during energy storage, and high-temperature compressed air is not suitable for storage. Summary of the invention

[0004] The purpose of the present invention is to provide a multi-stage heat energy recovery gravity compressed air energy storage system, which solves the problem of compressed air heat energy waste in traditional compressed air energy storage systems and improves the efficiency of air energy storage.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions: a multi-stage heat recovery gravity compressed air energy storage system, comprising: a water reservoir and at least two gas storage cavities, the water reservoir is higher than the gas storage cavity in the horizontal direction, generating a liquid level difference, the bottom of the water reservoir is respectively connected to the bottom of each gas storage cavity through a liquid pipeline, the top of the gas storage cavity is connected to a gas main pipe, the gas main pipe is respectively connected to a compressor unit and a generator unit through a branch pipe, a heat exchange liquid is arranged in the water reservoir, a heat exchange pipe is arranged at the bottom of the water reservoir, the heat exchange pipe extends to the outside of the water reservoir and is connected to a heat exchanger, the heat exchanger is connected to an external heat storage device or a heat-using facility, the compressor unit compresses air into the gas storage cavity for storage, and squeezes the heat exchange liquid in the gas storage cavity into the water reservoir, at the same time, the high-temperature compressed air in the gas storage cavity contacts and exchanges heat with the heat exchange liquid, the heat collected by the heat exchange liquid is utilized through the heat exchanger, and the temperature of the compressed air in the gas storage cavity is reduced, thereby improving the energy storage efficiency.

[0006] In the aforementioned multi-stage heat recovery gravity compressed air energy storage system, valves are provided at the water inlet at the bottom and the air inlet at the top of the air storage cavity to facilitate graded control.

[0007] In the aforementioned multi-stage heat recovery gravity compressed air energy storage system, valves are respectively provided on the two branch pipes connecting the compressor unit and the generator unit.

[0008] In the aforementioned multi-stage heat recovery gravity compressed air energy storage system, the heat exchange liquid in the water reservoir is one of water and heat exchange oil.

[0009] The aforementioned multi-stage heat recovery gravity compressed air energy storage system has a piston arranged in the water reservoir, and a gravity block is arranged on the top of the piston. The gravity block provides pressure for the heat exchange liquid, saves the volume of the heat exchange liquid, and increases the pressure of the compressed air storage.

[0010] The aforementioned multi-stage heat energy recovery gravity compressed air energy storage system, a bracket is provided on one side of the water reservoir, a crossbeam is provided on the top of the bracket, one end of the crossbeam extends to just above the water reservoir, both ends of the crossbeam are provided with wheels, the top of the gravity block is connected to one end of a chain, the other end of the chain is provided with a counterweight block which passes around two of the wheels in sequence, a gravity generator set is provided on the top of the bracket, a rotating gear is provided at the input end of the gravity generator set, and the rotating gear is meshed with the chain, so that compressed air can lift the gravity block to perform gravity energy storage, and when releasing the gas, the gravity block can also drive the gravity generator set to do work and generate electricity, thereby improving the energy storage efficiency; secondly, the gravity generator set can be used to lift the gravity block to reduce the pressure of compressed air storage, thereby making the pressure of compressed air storage adjustable.

[0011] In the aforementioned multi-stage heat recovery gravity compressed air energy storage system, limit devices are provided on both the upper and lower sides of the inner cavity side walls of the water storage tank to prevent the gravity block from moving too high or too low and causing damage to the equipment.

[0012] The aforementioned multi-stage heat recovery gravity compressed air energy storage system, the heat exchange tube includes two mutually parallel heat exchange main pipes, and a plurality of mutually parallel heat exchange branch pipes are arranged between the two heat exchange main pipes to increase the heat exchange area and improve the heat exchange efficiency. The heat exchange branch pipes are arranged obliquely between the heat exchange main pipes, and the angle a between the heat exchange branch pipes and the heat exchange main pipes along the liquid flow direction is 155°-170°, so that the flow rate of the liquid flowing through the heat exchange branch pipes is more uniform.

[0013] In the aforementioned multi-stage heat recovery gravity compressed air energy storage system, support pads are provided at the bottom of the heat exchange branch pipe and the heat exchange main pipe to prevent the heat exchange branch pipe and the heat exchange main pipe from being close to the water storage tank, thereby increasing the heat exchange area.

[0014] Compared with the prior art, the present invention adopts multiple air storage cavities to store energy, forming multi-level energy storage, and can store and release energy in batches and grades, which is more flexible in operation; the present invention adopts gravity blocks and heat exchange liquids to provide a high-pressure environment for compressed air in many aspects, and the gravity blocks can perform composite energy storage to improve energy storage efficiency; at the same time, the heat exchange liquid can exchange heat with the compressed air, and the stored heat of the compressed air can be recovered and reused, and the temperature of the stored compressed air can be reduced, which makes it easier to store and improves storage efficiency; and the gravity blocks can also be adjusted to make the storage pressure of the compressed air adjustable. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the system structure of the present invention;

[0016] Figure 2 It is a schematic diagram of the heat exchange tube structure of the present invention.

[0017] Figure numerals: 1-water reservoir, 2-gas storage chamber, 3-liquid pipeline, 4-gas main pipe, 5-branch pipe, 6-compressor unit, 7-generator unit, 8-heat exchange pipe, 81-heat exchange main pipe, 82-heat exchange branch pipe, 83-support pad, 9-heat exchanger, 10-piston, 11-gravity block, 12-bracket, 13-beam, 14-rotor, 15-chain, 16-counterweight block, 17-gravity generator set, 18-rotating gear, 19-limiting device, 20-, 21-, 22-, 23-.

[0018] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. DETAILED DESCRIPTION

[0019] Embodiment 1 of the present invention: A multi-stage heat recovery gravity compressed air energy storage system, comprising: a water reservoir 1 and at least two gas storage cavities 2, wherein the water reservoir 1 is higher than the gas storage cavity 2 in the horizontal direction, generating a liquid level difference, the bottom of the water reservoir 1 is respectively connected to the bottom of each gas storage cavity 2 through a liquid pipeline 3, the top of each gas storage cavity 2 is connected to a gas main pipe 4, the gas main pipe 4 is respectively connected to a compressor unit 6 and a generator unit 7 through a branch pipe 5, and a heat exchange liquid is arranged in the water reservoir 1, A heat exchange pipe 8 is provided at the bottom of the water reservoir 1. The heat exchange pipe 8 extends to the outside of the water reservoir 1 and is connected to a heat exchanger 9. The heat exchanger 9 is connected to an external heat storage device or a heat-using facility. The compressor unit 6 compresses the air into the gas storage cavity 2 for storage, and squeezes the heat exchange liquid in the gas storage cavity 2 into the water reservoir 1. At the same time, the high-temperature compressed air in the gas storage cavity 2 contacts and exchanges heat with the heat exchange liquid. The heat collected by the heat exchange liquid is utilized through the heat exchanger 9, and the temperature of the compressed air in the gas storage cavity 2 is reduced, thereby improving the energy storage efficiency.

[0020] Embodiment 2 of the present invention: A multi-stage heat recovery gravity compressed air energy storage system, comprising: a water reservoir 1 and at least two gas storage chambers 2, wherein the water reservoir 1 is higher than the gas storage chamber 2 in the horizontal direction, generating a liquid level difference, the bottom of the water reservoir 1 is connected to the bottom of each gas storage chamber 2 through a liquid pipeline 3, the top of each gas storage chamber 2 is connected to a gas main pipe 4, and the gas main pipe 4 is connected to a compressor unit 6 and a generator unit 7 through a branch pipe 5, and valves are provided at the water inlet at the bottom of the gas storage chamber 2 and the air inlet at the top to facilitate hierarchical control, and the compressor unit 6 and the generator unit 7 are connected. Valves are respectively provided on the two branch pipes 5 of the unit 7; heat exchange liquid is provided in the water reservoir 1, and a heat exchange pipe 8 is provided at the bottom of the water reservoir 1. The heat exchange pipe 8 extends to the outside of the water reservoir 1 and is connected to a heat exchanger 9, and the heat exchanger 9 is connected to an external heat storage device or a heat facility. The compressor unit 6 compresses the air into the gas storage cavity 2 for storage, and squeezes the heat exchange liquid in the gas storage cavity 2 into the water reservoir 1. At the same time, the high-temperature compressed air in the gas storage cavity 2 contacts and exchanges heat with the heat exchange liquid. The heat collected by the heat exchange liquid is utilized through the heat exchanger 9, and the temperature of the compressed air in the gas storage cavity 2 is reduced, thereby improving the energy storage efficiency.

[0021] Specifically, the heat exchange liquid in the water reservoir 1 is one of water and heat exchange oil, preferably heat exchange oil.

[0022] Embodiment 3 of the present invention: A multi-stage heat recovery gravity compressed air energy storage system, comprising: a water reservoir 1 and at least two gas storage chambers 2, wherein the water reservoir 1 is higher than the gas storage chamber 2 in the horizontal direction to generate a liquid level difference, the bottom of the water reservoir 1 is connected to the bottom of each gas storage chamber 2 through a liquid pipeline 3, the top of each gas storage chamber 2 is connected to a gas main pipe 4, and the gas main pipe 4 is connected to a compressor unit 6 and a generator unit 7 through a branch pipe 5, and valves are provided at the water inlet at the bottom of the gas storage chamber 2 and the air inlet at the top to facilitate hierarchical control, and the compressor unit 6 and the generator unit 7 are connected. Valves are respectively provided on the two branch pipes 5 of the unit 7; heat exchange liquid is provided in the water reservoir 1, and a heat exchange pipe 8 is provided at the bottom of the water reservoir 1. The heat exchange pipe 8 extends to the outside of the water reservoir 1 and is connected to a heat exchanger 9, and the heat exchanger 9 is connected to an external heat storage device or a heat facility. The compressor unit 6 compresses the air into the gas storage cavity 2 for storage, and squeezes the heat exchange liquid in the gas storage cavity 2 into the water reservoir 1. At the same time, the high-temperature compressed air in the gas storage cavity 2 contacts and exchanges heat with the heat exchange liquid. The heat collected by the heat exchange liquid is utilized through the heat exchanger 9, and the temperature of the compressed air in the gas storage cavity 2 is reduced, thereby improving the energy storage efficiency.

[0023] A piston 10 is arranged in the water reservoir 1, and a gravity block 11 is arranged on the top of the piston 10. The gravity block 11 provides pressure for the heat exchange liquid, saves the volume of the heat exchange liquid, and increases the pressure of the compressed air storage.

[0024] Specifically, the heat exchange liquid in the water reservoir 1 is one of water and heat exchange oil, preferably heat exchange oil.

[0025] Embodiment 4 of the present invention: A multi-stage heat recovery gravity compressed air energy storage system, comprising: a water reservoir 1 and at least two gas storage chambers 2, wherein the water reservoir 1 is higher than the gas storage chamber 2 in the horizontal direction to generate a liquid level difference, the bottom of the water reservoir 1 is connected to the bottom of each gas storage chamber 2 through a liquid pipeline 3, the top of each gas storage chamber 2 is connected to a gas main pipe 4, and the gas main pipe 4 is connected to a compressor unit 6 and a generator unit 7 through a branch pipe 5, and valves are provided at the water inlet at the bottom of the gas storage chamber 2 and the air inlet at the top to facilitate hierarchical control, and the compressor unit 6 and the generator unit 7 are connected. The two branch pipes 5 of the unit 7 are provided with valves respectively; the water reservoir 1 is provided with heat exchange liquid, the bottom of the water reservoir 1 is provided with heat exchange pipe 8, the heat exchange pipe 8 extends to the outside of the water reservoir 1 and is connected with a heat exchanger 9, the heat exchanger 9 is connected with an external heat storage device or heat using facility, the compressor unit 6 compresses the air into the gas storage cavity 2 for storage, and squeezes the heat exchange liquid in the gas storage cavity 2 into the water reservoir 1, at the same time, the high-temperature compressed air in the gas storage cavity 2 contacts and exchanges heat with the heat exchange liquid, the heat collected by the heat exchange liquid is utilized through the heat exchanger 9, and the temperature of the compressed air in the gas storage cavity 2 is reduced, thereby improving the energy storage efficiency. The heat exchange liquid in the water reservoir 1 is one of water and heat exchange oil, preferably heat exchange oil.

[0026] A piston 10 is provided in the water reservoir 1, and a gravity block 11 is provided on the top of the piston 10. The gravity block 11 provides pressure for the heat exchange liquid, saves the volume of the heat exchange liquid, and increases the pressure of the compressed air storage; a bracket 12 is provided on one side of the water reservoir 1, and a crossbeam 13 is provided on the top of the bracket 12. One end of the crossbeam 13 extends to the top of the water reservoir 1, and both ends of the crossbeam 13 are provided with a rotating wheel 14. The top of the gravity block 11 is connected to one end of a chain 15, and the other end of the chain 15 passes through the two The rotating wheel 14 is provided with a counterweight block 16, and a gravity generator set 17 is provided on the top of the bracket 12. The input end of the gravity generator set 17 is provided with a rotating gear 18, and the rotating gear 18 is meshed with the chain 15. Firstly, the compressed air can lift the gravity block 11 to store gravity energy. When releasing the gas, the gravity block 11 can also drive the gravity generator set 17 to do work and generate electricity, thereby improving the energy storage efficiency; secondly, the gravity generator set 17 can lift the gravity block 11 to reduce the pressure of compressed air storage, thereby making the compressed air storage pressure adjustable.

[0027] Specifically, limit devices 19 are provided on both upper and lower sides of the inner cavity side wall of the water storage tank 1 to prevent the gravity block 11 from moving too high or too low and causing damage to the equipment.

[0028] Embodiment 5 of the present invention: A multi-stage heat recovery gravity compressed air energy storage system, comprising: a water reservoir 1 and at least two gas storage chambers 2, wherein the water reservoir 1 is higher than the gas storage chamber 2 in the horizontal direction to generate a liquid level difference, the bottom of the water reservoir 1 is connected to the bottom of each gas storage chamber 2 through a liquid pipeline 3, the top of each gas storage chamber 2 is connected to a gas main pipe 4, and the gas main pipe 4 is connected to a compressor unit 6 and a generator unit 7 through a branch pipe 5, and valves are provided at the water inlet at the bottom of the gas storage chamber 2 and the air inlet at the top to facilitate hierarchical control, and the compressor unit 6 and the generator unit 7 are connected. The two branch pipes 5 of the unit 7 are provided with valves respectively; the water reservoir 1 is provided with heat exchange liquid, the bottom of the water reservoir 1 is provided with heat exchange pipe 8, the heat exchange pipe 8 extends to the outside of the water reservoir 1 and is connected with a heat exchanger 9, the heat exchanger 9 is connected with an external heat storage device or heat using facility, the compressor unit 6 compresses the air into the gas storage cavity 2 for storage, and squeezes the heat exchange liquid in the gas storage cavity 2 into the water reservoir 1, at the same time, the high-temperature compressed air in the gas storage cavity 2 contacts and exchanges heat with the heat exchange liquid, the heat collected by the heat exchange liquid is utilized through the heat exchanger 9, and the temperature of the compressed air in the gas storage cavity 2 is reduced, thereby improving the energy storage efficiency. The heat exchange liquid in the water reservoir 1 is one of water and heat exchange oil, preferably heat exchange oil.

[0029] A piston 10 is provided in the water reservoir 1, and a gravity block 11 is provided on the top of the piston 10. The gravity block 11 provides pressure for the heat exchange liquid, saves the volume of the heat exchange liquid, and increases the pressure of the compressed air storage; a bracket 12 is provided on one side of the water reservoir 1, and a crossbeam 13 is provided on the top of the bracket 12. One end of the crossbeam 13 extends to the top of the water reservoir 1, and both ends of the crossbeam 13 are provided with a rotating wheel 14. The top of the gravity block 11 is connected to one end of a chain 15, and the other end of the chain 15 passes through the two The rotating wheel 14 is provided with a counterweight block 16, and a gravity generator set 17 is provided on the top of the bracket 12. The input end of the gravity generator set 17 is provided with a rotating gear 18, and the rotating gear 18 is meshed with the chain 15. Firstly, the compressed air can lift the gravity block 11 to store gravity energy. When releasing the gas, the gravity block 11 can also drive the gravity generator set 17 to do work and generate electricity, thereby improving the energy storage efficiency; secondly, the gravity generator set 17 can lift the gravity block 11 to reduce the pressure of compressed air storage, thereby making the compressed air storage pressure adjustable.

[0030] Specifically, limit devices 19 are provided on both upper and lower sides of the inner cavity side wall of the water storage tank 1 to prevent the gravity block 11 from moving too high or too low and causing damage to the equipment.

[0031] The heat exchange pipe 8 includes two mutually parallel heat exchange main pipes 81, and a plurality of mutually parallel heat exchange branch pipes 82 are arranged between the two heat exchange main pipes 81 to increase the heat exchange area and improve the heat exchange efficiency. The heat exchange branch pipes 82 are arranged obliquely between the heat exchange main pipes 81. The angle a between the heat exchange branch pipes 82 and the heat exchange main pipes 81 along the liquid flow direction is 155°-170°, preferably 165°, so that the flow rate of the liquid flowing through the heat exchange branch pipes 82 is more uniform. The bottoms of the heat exchange branch pipes 82 and the heat exchange main pipes 81 are both provided with support pads 83 to prevent the heat exchange branch pipes 82 and the heat exchange main pipes 81 from being close to the water storage tank 1, thereby increasing the heat exchange area.

[0032] The working principle of an embodiment of the present invention: During use, the present invention has two working states: energy storage and energy release.

[0033] in:

[0034] When storing energy, the compressor unit 6 compresses air into the gas storage cavity 2, squeezes the heat exchange liquid in the gas storage cavity 2 to flow back to the water storage tank 1, and lifts the piston 10 to drive the gravity block 11 to rise, so as to store energy. At the same time, the compressed air exchanges heat with the heat exchange liquid to reduce the temperature of the compressed air, and the heat collected by the heat exchange liquid is recycled through the heat exchange pipe 8;

[0035] When releasing energy to generate electricity, compressed air enters the generator set 7 to expand and generate electricity. At the same time, the heat exchange liquid in the water reservoir 1 flows into the air storage chamber 2, the piston 10 and the gravity block 11 descend, and the gravity block 11 can drive the rotating gear 18 to rotate through the chain 15. The rotating gear 18 rotates to make the gravity generator set 17 generate electricity synchronously.

Claims

1. A multi-stage heat recovery gravity compressed air energy storage system, characterized in that: include: A water reservoir (1) and at least two gas storage chambers (2), wherein the water reservoir (1) is higher than the gas storage chambers (2) in the horizontal direction, the bottom of the water reservoir (1) is respectively connected to the bottom of each gas storage chamber (2) through a liquid pipeline (3), the top of each gas storage chamber (2) is connected to a gas main pipe (4), and the gas main pipe (4) is respectively connected to a compressor unit (6) and a generator unit (7) through a branch pipe (5), a heat exchange liquid is arranged in the water reservoir (1), a heat exchange pipe (8) is arranged at the bottom of the water reservoir (1), the heat exchange pipe (8) extends to the outside of the water reservoir (1) and is connected to a heat exchanger (9), and the heat exchanger (9) is connected to an external heat storage device or a heat-using facility.

2. A multi-stage heat recovery gravity compressed air energy storage system according to claim 1, characterized in that: Valves are provided at the water inlet at the bottom and the air inlet at the top of the gas storage cavity (2).

3. The multi-stage heat recovery gravity compressed air energy storage system according to claim 1 is characterized in that: Valves are respectively provided on the two branch pipes (5) connecting the compressor unit (6) and the generator unit (7).

4. The multi-stage heat recovery gravity compressed air energy storage system according to claim 1, characterized in that: The heat exchange liquid in the water reservoir (1) is one of water and heat exchange oil.

5. The multi-stage heat recovery gravity compressed air energy storage system according to claim 1, characterized in that: A piston (10) is arranged in the water reservoir (1), and a gravity block (11) is arranged on the top of the piston (10).

6. A multi-stage heat recovery gravity compressed air energy storage system according to claim 5, characterized in that: A support (12) is provided on one side of the water reservoir (1), a crossbeam (13) is provided on the top of the support (12), one end of the crossbeam (13) extends to the top of the water reservoir (1), both ends of the crossbeam (13) are provided with rotating wheels (14), the top of the gravity block (11) is connected to one end of a chain (15), the other end of the chain (15) is provided with a counterweight (16) which passes through two rotating wheels (14) in sequence, the top of the support (12) is provided with a gravity generator set (17), the input end of the gravity generator set (17) is provided with a rotating gear (18), and the rotating gear (18) is meshed with the chain (15).

7. A multi-stage heat recovery gravity compressed air energy storage system according to claim 6, characterized in that: Limiting devices (19) are provided on both upper and lower sides of the inner cavity side wall of the water storage tank (1).

8. The multi-stage heat recovery gravity compressed air energy storage system according to claim 1, characterized in that: The heat exchange tube (8) comprises two mutually parallel heat exchange main pipes (81), a plurality of mutually parallel heat exchange branch pipes (82) are arranged between the two heat exchange main pipes (81), and the heat exchange branch pipes (82) are arranged obliquely between the heat exchange main pipes (81), and an angle a between the heat exchange branch pipes (82) and the heat exchange main pipes (81) along the liquid flow direction is 155°-170°.

9. A multi-stage heat recovery gravity compressed air energy storage system according to claim 8, characterized in that: The bottoms of the heat exchange branch pipe (82) and the heat exchange main pipe (81) are both provided with support pads (83).

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