A constant pressure compressed gas energy storage system and use method

Abstract

The present invention relates to the field of energy storage technology, and in particular to a constant-pressure compressed gas energy storage system and a method of use. A constant-pressure compressed gas energy storage system comprises: a constant-pressure gas storage tank, suitable for constant-pressure storage of compressed gas; an expansion and exhaust assembly, comprising an outlet pipeline and a first expander, the outlet pipeline is connected to the constant-pressure gas storage tank, a first expander is arranged on the outlet pipeline, and the first expander is suitable for connecting to a generator set; a heat storage assembly, comprising a circulating heat storage pipeline and a heat storage device, the circulating heat storage pipeline is provided with a liquid outlet branch, the liquid outlet pipeline is connected to the constant-pressure gas storage tank, a heat storage fluid flows in the circulating heat storage pipeline, and the constant-pressure gas storage tank contains a heat storage fluid. The present invention solves the problem that during the energy release process of a constant-volume compressed gas energy storage system, the pressure in the gas storage device gradually decreases due to the continuous outflow of compressed gas from the gas storage device, and after the compressed gas pressure decreases, the compressed gas cannot generate electricity at full power after reaching the expander, thereby limiting the total power output of the power generation system.

Description

Technical Field

[0001] The present invention relates to the field of energy storage technology, and in particular to a constant-pressure compressed gas energy storage system and a use method thereof. Background Art

[0002] Power storage technology can adjust electric energy in time and space, greatly increase the grid connection rate of renewable energy, and enhance the stability and adjustability of renewable energy power. It is a key technology of the energy revolution. Compressed gas energy storage (CAES) system is a storage technology similar to pumped storage, with large-scale and low-cost characteristics.

[0003] During the energy release process of constant volume compressed gas energy storage, as the compressed gas continuously flows out of the gas storage device, the internal pressure and temperature of the gas storage device will gradually decrease. When the pressure drops to the inlet pressure of the expander, it will not be able to meet the full power generation. The temperature drop will accelerate the pressure drop and limit the total power output of the power generation system. At the same time, the low-temperature sensible heat and waste heat contained in the low-temperature heat storage working fluid at the hot side outlet of the reheater cannot be effectively utilized, resulting in a large amount of energy waste. Summary of the invention

[0004] In view of this, the present invention provides a constant-pressure compressed gas energy storage system and a method of use, so as to solve the problem that during the energy release process of constant-volume compressed gas energy storage, the pressure inside the gas storage device will gradually decrease due to the continuous flow of compressed gas out of the gas storage device. After the pressure of the compressed gas is reduced, the compressed gas with reduced pressure cannot generate electricity at full power after reaching the expander, thereby limiting the total power output of the power generation system.

[0005] In a first aspect, the present invention provides a constant pressure compressed gas energy storage system, comprising:

[0006] A constant pressure gas storage tank, wherein the constant pressure gas storage tank is suitable for storing compressed gas at a constant pressure;

[0007] An expansion and exhaust assembly, the expansion and exhaust assembly comprising an outlet pipeline and a first expander, the outlet pipeline is communicated with the constant pressure gas storage tank, the outlet pipeline is provided with a first expander, and the first expander is suitable for connecting to a generator set;

[0008] A heat storage component, wherein the heat storage component comprises a circulating heat storage pipeline and a heat storage device, wherein the circulating heat storage pipeline is provided with a liquid outlet branch, wherein the liquid outlet pipeline is connected to a constant pressure gas storage tank, wherein a heat storage fluid flows in the circulating heat storage pipeline, and wherein the constant pressure gas storage tank contains a heat storage fluid.

[0009] During peak hours of electricity consumption, when power generation is required, the compressed gas in the constant pressure gas tank enters the first expander through the gas outlet pipeline, the compressed gas pushes the first expander to move, and the first expander drives the generator set to generate electricity, and the heat storage fluid in the heat storage device enters the constant pressure gas tank through the liquid outlet branch, so that the gas pressure in the constant pressure gas tank remains constant, and the compressed gas flows out of the constant pressure gas tank and the heat storage fluid enters the constant pressure gas tank, ensuring the stability of the gas pressure in the constant pressure gas tank, thereby keeping the pressure entering the first expander through the gas outlet pipeline stable, so that the generator set can generate electricity normally.

[0010] In an optional embodiment, the expansion exhaust assembly is provided with a first reheat heat exchanger, which is arranged between the first expander and the constant pressure gas storage tank, the gas outlet pipeline and the circulating heat storage pipeline are respectively arranged through the first reheat heat exchanger, and a regulating valve is provided between the first reheat heat exchanger and the constant pressure gas storage tank.

[0011] By setting up the first reheat heat exchanger, the heat of the heat storage fluid in the circulating heat storage pipeline is transferred to the compressed gas in the outlet pipeline through the first reheat heat exchanger to heat the compressed gas in the outlet pipeline. In addition, after the heat storage fluid enters the constant pressure gas storage tank, the temperature in the constant pressure gas storage tank will increase, slowing down the speed of the temperature drop of the constant pressure gas storage tank caused by the discharge of compressed gas, thereby realizing the effective utilization of low-temperature sensible heat waste heat.

[0012] In an optional embodiment, the first reheat heat exchanger is disposed between the first expander and the constant pressure gas storage tank, and a regulating valve is provided between the first reheat heat exchanger and the constant pressure gas storage tank.

[0013] In an optional embodiment, the expansion and exhaust assembly includes a second expander, the second expander is arranged on the gas outlet pipeline, the first expander and the second expander are arranged in series, and the second expander is suitable for connecting to a generator set.

[0014] In an optional embodiment, it also includes a second reheat heat exchanger and a heat release branch, the second reheat heat exchanger is arranged between the first expansion machine and the second expansion machine, the two ends of the heat release branch are respectively connected to the liquid outlet branch, and the heat release branch and the gas outlet pipeline are respectively arranged through the second expansion machine.

[0015] In an optional embodiment, the liquid outlet branch is provided with a second switch valve, a circulation pump, a booster pump and a check valve in sequence in a direction away from the heat storage device.

[0016] In an optional embodiment, it also includes a compressed air intake component, which includes an intake pipeline, a first cooling heat exchanger and a first compressor. The intake pipeline is connected to the constant pressure air storage tank, and a first compressor is provided on the intake pipeline. The intake pipeline and the circulating heat storage pipeline are respectively arranged through the first cooling heat exchanger.

[0017] When electricity consumption is low, the first compressor compresses external gas and enters the constant pressure gas storage tank through the air intake pipeline. The heat storage fluid in the constant pressure gas storage tank flows to the heat storage device through the circulating heat storage pipeline. The first cooling heat exchanger transfers the heat generated by the compressed gas to the circulating heat storage pipeline, thereby solving the problem that during the energy storage process of constant volume compressed gas energy storage, the pressure and temperature inside the gas storage device will gradually increase as the gas continuously enters the gas storage device. The increase in pressure increases the power consumption per unit gas storage mass, and the increase in temperature reduces the gas storage volume.

[0018] In an optional embodiment, the first cooling heat exchanger is arranged between the first compressor and the constant pressure gas storage tank, a first switching valve is provided between the first cooling heat exchanger and the constant pressure gas storage tank, and the pressure in the constant pressure gas storage tank is greater than the pressure in the heat storage device.

[0019] In an optional embodiment, the compressed air intake assembly also includes a second compressor, which is arranged on the air intake pipeline. The first compressor and the second compressor are sequentially arranged on the air intake pipeline in a direction away from the constant pressure air storage tank, and the first compressor and the second compressor are arranged in series.

[0020] In an optional embodiment, it also includes a second cooling heat exchanger and a heat recovery branch, the second cooling heat exchanger is arranged between the first compressor and the second compressor, the circulating heat storage pipeline is provided with a liquid inlet branch, the two ends of the heat recovery branch are respectively connected to the liquid inlet branch, the heat recovery branch and the air intake pipeline are respectively arranged through the second cooling heat exchanger, and the liquid inlet branch is provided with a pressure reducing valve.

[0021] In an optional embodiment, a connecting pipeline is further included, one end of which is connected to the constant pressure gas storage tank, and the other end is connected to the circulating heat storage pipeline, and the connection between the connecting pipeline and the circulating heat storage pipeline is located between the liquid inlet branch and the liquid outlet branch.

[0022] In a second aspect, the present invention also provides a method for using a constant-pressure compressed gas energy storage system, including: during peak electricity consumption, the compressed gas in the constant-pressure gas storage tank enters the first expander through the outlet pipeline, the compressed gas drives the first expander to move, and the first expander drives the generator set to generate electricity, and the heat storage fluid in the heat storage device enters the constant-pressure gas storage tank to keep the gas pressure in the constant-pressure gas storage tank constant.

[0023] The constant-pressure compressed gas energy storage system provided by the present application has the following advantages: (1) During the off-peak period of electricity consumption, the heat storage fluid in the constant-pressure gas storage tank enters the heat storage device through the connecting branch and the liquid inlet branch, so that the heat storage fluid in the constant-pressure gas storage tank flows out and the compressed gas enters, realizing the near-constant-pressure energy storage process of the constant-pressure gas storage tank. At the same time, the heat storage fluid will take away the heat in the constant-pressure gas storage tank during the flow, slowing down the temperature and pressure rise in the constant-pressure gas storage tank, improving the gas storage capacity of the entire constant-pressure gas storage tank, and reducing the energy storage power consumption; (2) During the peak period of electricity consumption, the heat storage fluid in the liquid storage pipe enters the constant-pressure gas storage tank through the liquid outlet branch and the connecting branch, so that the heat storage fluid in the constant-pressure gas storage tank enters and the compressed gas flows out, realizing the constant The compressed gas in the high-pressure gas storage tank flows out at a near-constant pressure during the outflow process, ensuring that the pressure of the compressed gas entering the outlet pipeline is constant. The space occupied by the heat storage fluid and the heat input slow down the temperature and pressure drop in the constant-pressure gas storage device, achieving near-constant-pressure energy release, increasing the system output capacity and ensuring the utilization of the constant-pressure gas storage tank; (3) The heat storage fluid is injected into the constant-pressure gas storage tank, which can transfer low-temperature heat to the compressed gas while occupying space, realizing low-temperature waste heat recovery, reducing system energy loss and improving system efficiency; (4) A booster pump is added, and a cooling pump and a cold fluid storage device are eliminated, which reduces the initial investment, enhances system efficiency and density, and greatly improves the overall economy. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 Schematic diagram of a constant-pressure compressed gas energy storage system according to an embodiment of the present invention.

[0026] Description of the reference numerals: 1. Compression air intake assembly; 101. First compressor; 102. Air intake pipeline; 103. First cooling heat exchanger; 104. Second compressor; 105. Second cooling heat exchanger; 106. First switch valve; 107. Air inlet; 2. Constant pressure air storage tank; 3. Expansion exhaust assembly; 301. First expander; 302. Air outlet pipeline; 303. First reheat heat exchanger; 304. Second expander; 305. Second Reheat heat exchanger; 306, regulating valve; 307, exhaust port; 4, heat storage component; 401, heat storage device; 402, circulating heat storage pipeline; 4021, liquid inlet branch; 4022, liquid outlet branch; 403, heat recovery branch; 404, heat release branch; 405, pressure reducing valve; 406, second switch valve; 407, circulation pump; 408, booster pump; 409, check valve; 410, connecting pipeline; 411, heat storage fluid. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are 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 those skilled in the art without creative work are within the scope of protection of the present invention.

[0028] Combine the following Figure 1 , describing an embodiment of the present invention.

[0029] According to an embodiment of the present invention, on the one hand, a constant pressure compressed gas energy storage system is provided, comprising:

[0030] like Figure 1 As shown, in one embodiment, a constant pressure gas storage tank 2 is provided, wherein the constant pressure gas storage tank 2 is suitable for compressing gas for constant pressure storage; an expansion exhaust component 3, wherein the expansion exhaust component 3 includes an outlet pipeline 302 and a first expander 301, wherein the outlet pipeline 302 is connected to the constant pressure gas storage tank 2, wherein the outlet pipeline 302 is provided with a first expander 301, and wherein the first expander 301 is suitable for connecting to a generator set; a heat storage component 4, wherein the heat storage component 4 includes a circulating heat storage pipeline 402 and a heat storage device 401, wherein the circulating heat storage pipeline 402 is provided with a liquid outlet branch 4022, wherein the liquid outlet pipeline is connected to the constant pressure gas storage tank 2, wherein a heat storage fluid 411 flows in the circulating heat storage pipeline 402, and wherein the constant pressure gas storage tank 2 contains the heat storage fluid 411.

[0031] In this embodiment, when power generation is required during peak hours of electricity consumption, the compressed gas in the constant pressure gas tank 2 enters the first expander 301 through the gas outlet pipeline 302, and the compressed gas pushes the first expander 301 to move, and the first expander 301 drives the generator set to generate electricity, and the heat storage fluid 411 in the heat storage device 401 enters the constant pressure gas tank 2 through the liquid outlet branch 4022, so that the gas pressure in the constant pressure gas tank 2 remains constant, so that the compressed gas flows out of the constant pressure gas tank 2 and the heat storage fluid 411 enters the constant pressure gas tank 2, ensuring that the gas pressure in the constant pressure gas tank 2 is stable, so that the pressure entering the first expander 301 through the gas outlet pipeline 302 remains stable, so that the generator set can generate electricity normally.

[0032] like Figure 1 As shown, in one embodiment, the expansion exhaust component 3 is provided with a first reheat heat exchanger 303, the first reheat heat exchanger 303 is arranged between the first expander 301 and the constant pressure gas storage tank 2, the gas outlet pipeline 302 and the circulating heat storage pipeline 402 are respectively arranged through the first reheat heat exchanger 303, and a regulating valve 306 is provided between the first reheat heat exchanger 303 and the constant pressure gas storage tank 2.

[0033] In this embodiment, the first reheat heat exchanger 303 transfers the heat of the thermal storage fluid 411 to the compressed gas flowing out of the gas outlet pipeline 302, and the regulating valve 306 controls and adjusts the gas flow in the gas outlet pipeline 302. It should be noted that the compressed gas is a compressible gas such as compressed air and compressed carbon dioxide.

[0034] like Figure 1 As shown, in one embodiment, the expansion and exhaust assembly 3 includes a second expander 304, which is arranged on the gas outlet pipeline 302, the first expander 301 and the second expander 304 are arranged in series, and the second expander 304 is suitable for connecting to a generator set.

[0035] In this embodiment, the compressed gas after passing through the first expander 301 enters the second expander 304 again, pushing the second expander 304 to move, and the second expander 304 drives the generator set to generate electricity.

[0036] like Figure 1 As shown, in one embodiment, it also includes a second reheat heat exchanger 305 and a heat release branch 404. The second reheat heat exchanger 305 is arranged between the first expansion machine 301 and the second expansion machine 304. The two ends of the heat release branch 404 are respectively connected to the liquid outlet branch 4022, and the heat release branch 404 and the gas outlet pipeline 302 are respectively arranged through the second expansion machine 304.

[0037] In this embodiment, the heat storage fluid 411 flowing out of the heat storage device 401 flows in the liquid outlet branch 4022, and the heat storage fluid 411 enters the heat release branch 404. The heat of the heat storage fluid 411 is transferred to the gas outlet pipeline 302 through the second reheat heat exchanger 305, and the compressed gas is heated again before entering the second expander 304. It should be noted that the liquid outlet branch 4022 is connected to the liquid inlet branch 4021 to form a ring-shaped circulating heat storage pipeline 402.

[0038] like Figure 1 As shown, in one embodiment, the liquid outlet branch 4022 is provided with a second switch valve 406, a circulation pump 407, a booster pump 408 and a check valve 409 in sequence in the direction away from the heat storage device 401. The second switch valve 406 controls the switch of the liquid outlet branch 4022, the circulation pump 407 provides circulation power, the booster pump increases the pressure of the heat storage fluid 411, so that the pressure of the heat storage fluid 411 is greater than the pressure in the constant pressure gas storage tank 2, so that the heat storage fluid 411 enters the constant pressure gas storage tank 2, and the check valve 409 prevents the heat storage fluid 411 from backflowing.

[0039] like Figure 1 As shown, in one embodiment, it also includes a compressed air intake assembly 1, including an air intake pipeline 102, a first cooling heat exchanger 103 and a first compressor 101. The air intake pipeline 102 is connected to the constant pressure air storage tank 2. The first compressor 101 is provided on the air intake pipeline 102. The air intake pipeline 102 and the circulating heat storage pipeline 402 are respectively arranged through the first cooling heat exchanger 103.

[0040] In this embodiment, when electricity consumption is low, the first compressor 101 compresses external gas and enters the constant pressure gas storage tank 2 through the air intake pipe 102, and the heat storage fluid 411 in the constant pressure gas storage tank 2 flows into the heat storage device 401 through the circulating heat storage pipe 402, and the first cooling heat exchanger 103 transfers the heat generated by the compressed gas to the circulating heat storage pipe 402. Specifically, the heat storage fluid 411 is a heat storage medium such as water and oil. By setting a constant pressure gas storage tank 2 during the energy storage process, the heat storage fluid 411 is discharged while the compressed gas enters, thereby increasing the storage space in the constant pressure gas storage tank 2. In addition, since part of the heat of the compressed gas will be taken away by the heat storage fluid 411 in the circulating heat storage pipe 402, this will slow down the temperature increase rate in the constant pressure gas storage tank 2 and ensure the stability of the gas storage amount.

[0041] like Figure 1 As shown, in one embodiment, the first cooling heat exchanger 103 is arranged between the first compressor 101 and the constant pressure gas storage tank 2, and a first switching valve 106 is provided between the first cooling heat exchanger 103 and the constant pressure gas storage tank 2, and the pressure in the constant pressure gas storage tank 2 is greater than the pressure in the heat storage device 401.

[0042] In this embodiment, the first compressor 101 is used to compress gas, and the position of the first cooling heat exchanger 103 is set to recover compression heat, that is, when the first compressor 101 compresses gas and the compressed gas carries the generated heat through the first cooling heat exchanger 103, the first cooling heat exchanger 103 transfers the heat in the compressed gas to the heat storage fluid 411 in the circulating heat storage pipeline 402. Since the pressure in the constant pressure gas storage tank 2 is greater than the pressure in the heat storage device 401, the heat storage fluid 411 in the constant pressure heat storage tank flows from the constant pressure gas storage tank 2 toward the heat storage device 401. Since the heat storage fluid 411 in the constant pressure gas storage tank 2 is reduced, more compressed gas will enter the constant pressure gas storage tank 2, so that the space in the constant pressure gas storage tank 2 is effectively utilized, so that the compressed gas in the constant pressure gas storage tank 2 is kept in a constant pressure state.

[0043] like Figure 1 As shown, in one embodiment, the compressed air intake assembly 1 also includes a second compressor 104, which is arranged on the air intake pipeline 102. The first compressor 101 and the second compressor 104 are arranged in sequence on the air intake pipeline 102 in a direction away from the constant pressure air storage tank 2, and the first compressor 101 and the second compressor 104 are arranged in series.

[0044] In this embodiment, the gas entering from the air inlet 107 of the air inlet pipeline 102 is compressed by the second compressor 104 and the first compressor 101 in sequence, and the gas enters the constant pressure gas storage tank 2 after passing through the first compressor 101 .

[0045] like Figure 1 As shown, in one embodiment, it also includes a second cooling heat exchanger 105 and a heat recovery branch 403. The second cooling heat exchanger 105 is arranged between the first compressor 101 and the second compressor 104. The circulating heat storage pipeline 402 is provided with a liquid inlet branch 4021. The two ends of the heat recovery branch 403 are respectively connected to the liquid inlet branch 4021. The heat recovery branch 403 and the air intake pipeline 102 are respectively arranged through the second cooling heat exchanger 105.

[0046] In this embodiment, after the second compressor 104 compresses the gas, a second cooling heat exchanger 105 is provided to recover the heat of the compressed gas, so that the compressed gas is cooled before entering the first compressor 101, so that the heat of the compressed gas in the intake pipe 102 enters the heat recovery branch 403, and the heat storage fluid 411 in the heat recovery branch 403 enters the liquid inlet branch 4021, and finally enters the heat storage device 401. Figure 1 As shown, a pressure reducing valve 405 is provided on the liquid inlet branch 4021 , and the pressure and flow rate of the thermal storage fluid 411 in the liquid inlet branch 4021 are controlled by the pressure reducing valve 405 .

[0047] like Figure 1As shown, in one embodiment, it also includes a connecting pipeline 410, one end of which is connected to the constant pressure gas storage tank 2, and the other end is connected to the circulating heat storage pipeline 402, and the connection between the connecting pipeline 410 and the circulating heat storage pipeline 402 is located between the liquid inlet branch 4021 and the liquid outlet branch 4022.

[0048] In this embodiment, a pipeline between the constant pressure gas storage tank 2 and the heat storage device 401 is formed by the connecting pipeline 410 and the liquid outlet branch 4022, and the heat storage fluid 411 in the pipeline flows from the heat storage device 401 to the constant pressure gas storage tank 2; a pipeline between the constant pressure gas storage tank 2 and the heat storage device 401 is formed by the connecting pipeline and the liquid inlet branch 4021, and the heat storage fluid 411 in the pipeline flows from the constant pressure gas storage tank 2 to the liquid storage tank.

[0049] A method for using a constant pressure compressed gas energy storage system comprises the following steps:

[0050] 1) When the power consumption is low, the first switch valve 106 is opened, the second switch valve 406 is closed, the circulation pump 407 and the booster pump 408 are closed, and the gas enters through the air inlet 107 of the air inlet pipeline 102, and enters the constant pressure gas storage tank 2 through the second compressor 104 and the first compressor 101 in sequence. Since the gas enters the constant pressure gas storage tank 2 after being compressed, the pressure of the constant pressure gas storage tank 2 will increase. The heat storage liquid in the constant pressure gas storage tank 2 enters the heat storage device 401 through the connecting pipeline 410, the heat recovery branch 403 and the liquid inlet branch 4021. During the whole process, after the gas is compressed by the second compressor 104, the heat of the compressed gas in the air inlet pipeline 102 is transferred to the heat recovery branch 403 through the second cooling heat exchanger 105. After the compressed gas after passing through the second cooling heat exchanger 105 is compressed by the first compressor 101, the heat of the compressed gas in the air inlet pipeline 102 is transferred to the liquid inlet branch 4021 through the first cooling heat exchanger 103;

[0051] 2) During the peak period of electricity consumption, the first switch valve 106 is closed, the second switch valve 406 is opened, the circulation pump 407 and the booster pump 408 are turned on, and the compressed gas in the constant pressure gas storage tank 2 is discharged through the gas outlet pipeline 302, and then reaches the exhaust port 307 through the first expander 301 and the second expander 304. The outflow of compressed gas will cause the pressure in the constant pressure gas storage tank 2 to decrease, and the heat storage fluid 411 in the heat storage device 401 will enter the constant pressure gas storage tank 2 through the liquid outlet branch 4022, the heat release branch 404 and the connecting pipeline 410. In the whole process, the compressed gas drives the The first expander 301 and the second expander 304 are driven to perform mechanical movements respectively, and the first expander 301 and the second expander 304 respectively drive the generator sets to generate electricity; before the compressed gas passes through the first expander 301, the heat of the heat storage fluid 411 in the liquid outlet branch 4022 is transferred to the compressed gas in the gas outlet pipeline 302 via the first reheat heat exchanger 303 for heating; before the compressed gas passes through the second expander 304, the heat of the heat storage fluid 411 in the liquid outlet branch 4022 is transferred to the compressed gas in the gas outlet pipeline 302 via the second reheat heat exchanger 305 for heating.

[0052] The constant-pressure compressed gas energy storage system provided by the present application has the following advantages: (1) During the off-peak period of electricity consumption, the heat storage fluid 411 in the constant-pressure gas storage tank 2 enters the heat storage device 401 through the connecting branch and the liquid inlet branch 4021, so that the heat storage fluid 411 in the constant-pressure gas storage tank 2 flows out and the compressed gas enters, realizing the near-constant-pressure energy storage process of the constant-pressure gas storage tank 2. At the same time, the heat storage fluid 411 will take away the heat in the constant-pressure gas storage tank 2 during the flow, slowing down the temperature and pressure rise in the constant-pressure gas storage tank 2, improving the gas storage capacity of the entire constant-pressure gas storage tank 2, and reducing the energy storage power consumption; (2) During the peak period of electricity consumption, the heat storage fluid 411 in the liquid storage pipe enters the constant-pressure gas storage tank 2 through the liquid outlet branch 4022 and the connecting branch, so that the heat storage fluid 411 in the constant-pressure gas storage tank 2 enters and the compressed gas enters. (3) The heat storage fluid 411 is injected into the constant pressure gas storage tank 2, which can transfer low-temperature heat to the compressed gas while occupying space, thus realizing low-temperature waste heat recovery, reducing system energy loss and improving system efficiency. (4) The booster pump 408 is added, the cooling pump and the cold fluid storage device are eliminated, which reduces the initial investment, enhances system efficiency and density, and greatly improves the overall economy.

[0053] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A constant pressure compressed gas energy storage system, characterized in that: include: A constant pressure gas storage tank (2), wherein the constant pressure gas storage tank (2) is suitable for storing compressed gas at a constant pressure; an expansion and exhaust assembly (3), the expansion and exhaust assembly (3) comprising an air outlet pipeline (302) and a first expander (301), the air outlet pipeline (302) being in communication with the constant pressure gas storage tank (2), the air outlet pipeline (302) being provided with the first expander (301), the first expander (301) being used to connect to a generator set; A heat storage component (4), the heat storage component (4) comprising a circulating heat storage pipeline (402) and a heat storage device (401), the circulating heat storage pipeline (402) being provided with a liquid outlet branch (4022), the liquid outlet branch (4022) being connected to a constant pressure gas storage tank (2), a heat storage fluid (411) flowing in the circulating heat storage pipeline (402), and the constant pressure gas storage tank (2) containing the heat storage fluid (411); The expansion exhaust assembly (3) is provided with a first reheat heat exchanger (303), the first reheat heat exchanger (303) is arranged between the first expander (301) and the constant pressure gas storage tank (2), the gas outlet pipeline (302) and the circulating heat storage pipeline (402) are respectively arranged through the first reheat heat exchanger (303), and a regulating valve (306) is provided between the first reheat heat exchanger (303) and the constant pressure gas storage tank (2); The liquid outlet branch (4022) is provided with a second switch valve (406), a circulation pump (407), a booster pump (408) and a check valve (409) in sequence in a direction away from the heat storage device (401); It also comprises a compression air intake assembly (1), the compression air intake assembly (1) comprising an air intake pipeline (102), a first cooling heat exchanger (103) and a first compressor (101), the air intake pipeline (102) being in communication with the constant pressure air storage tank (2), the air intake pipeline (102) being provided with the first compressor (101), the air intake pipeline (102) and the circulating heat storage pipeline (402) being respectively provided through the first cooling heat exchanger (103); It also comprises a connecting pipeline (410), one end of which is connected to the constant pressure gas storage tank (2), and the other end of which is connected to the circulating heat storage pipeline (402), and the connection between the connecting pipeline (410) and the circulating heat storage pipeline (402) is located between the liquid inlet branch (4021) and the liquid outlet branch (4022); During peak electricity consumption, the compressed gas in the constant pressure gas storage tank (2) enters the first expander (301) through the gas outlet pipeline (302), the compressed gas drives the first expander (301) to move, the first expander (301) drives the generator set to generate electricity, and the heat storage fluid (411) in the heat storage device (401) enters the constant pressure gas storage tank (2), so that the gas pressure in the constant pressure gas storage tank (2) remains constant.

2. The constant pressure compressed gas energy storage system according to claim 1, characterized in that: The expansion and exhaust assembly (3) comprises a second expander (304), the second expander (304) being arranged on the gas outlet pipeline (302), the first expander (301) and the second expander (304) being arranged in series, and the second expander (304) being suitable for connecting to a generator set.

3. The constant pressure compressed gas energy storage system according to claim 2, characterized in that: The invention also comprises a second reheat heat exchanger (305) and a heat release branch (404); the second reheat heat exchanger (305) is arranged between the first expander (301) and the second expander (304); two ends of the heat release branch (404) are respectively connected to the liquid outlet branch (4022); the heat release branch (404) and the gas outlet pipeline (302) are respectively arranged to pass through the second expander (304).

4. The constant pressure compressed gas energy storage system according to claim 3, characterized in that: The first cooling heat exchanger (103) is arranged between the first compressor (101) and the constant pressure gas storage tank (2), a first switch valve (106) is arranged between the first cooling heat exchanger (103) and the constant pressure gas storage tank (2), and the pressure in the constant pressure gas storage tank (2) is greater than the pressure in the heat storage device (401).

5. The constant pressure compressed gas energy storage system according to claim 4, characterized in that: The compressed air intake assembly (1) further comprises a second compressor (104), wherein the second compressor (104) is arranged on an air intake pipeline (102), wherein the first compressor (101) and the second compressor (104) are arranged in sequence on the air intake pipeline (102) in a direction away from the constant pressure air storage tank (2), and the first compressor (101) and the second compressor (104) are arranged in series.

6. The constant pressure compressed gas energy storage system according to claim 5, characterized in that: It also includes a second cooling heat exchanger (105) and a heat recovery branch (403); the second cooling heat exchanger (105) is arranged between the first compressor (101) and the second compressor (104); the circulating heat storage pipeline (402) is provided with a liquid inlet branch (4021); both ends of the heat recovery branch (403) are respectively connected to the liquid inlet branch (4021); the heat recovery branch (403) and the air intake pipeline (102) are respectively arranged to pass through the second cooling heat exchanger (105); and a pressure reducing valve (405) is provided on the liquid inlet branch (4021).

Images