Start-stop control system and method for multi-stage compressor of compressed air energy storage power station

Abstract

The invention discloses a compressed air energy storage power station multi-stage compressor start-stop control system and method, and belongs to the technical field of compressed air energy storage, the compressed air energy storage power station multi-stage compressor start-stop control system comprises two compressor units and an expansion unit connected with the compressor units, each compressor unit comprises four stages of compressors connected in series, an anti-surge valve and an emptying valve are arranged on the outlet side of each stage of compressor in parallel, and every two adjacent stages of compressors are connected through a check valve, a butterfly valve shut-off valve, an energy storage heat exchanger and an aftercooler. Meanwhile, an aftercooler, a gas-liquid separator and a gas injection valve are arranged on the outlet side of the last-stage compressor in each compressor unit; the expansion unit and the compressor unit form switchable gas path coupling through an electric shut-off valve. The starting time of the compressed air energy storage system can be shortened, gas in the compressed air energy storage system is prevented from being exhausted during shutdown, and energy loss is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of compressed air energy storage, and in particular relates to a start-stop control system and method for a multi-stage compressor of a compressed air energy storage power station. Background Art

[0002] The country supports the construction of high-tech energy storage industrialization bases, promotes the integrated development of production, education, research and application, and continuously strengthens the new energy storage industry.

[0003] Compressed air energy storage, as a major component of new energy storage, is an effective means to improve the regulation capacity of the power system and has the conditions for large-scale commercial application. At present, 300MW compressed air energy storage power stations have been under construction. With the implementation of the project, higher requirements are put forward for the start-up time, shutdown time, load increase rate and load shedding rate of compressed air energy storage power stations, that is, to respond to grid demand in a short time, reduce the loss of spare electricity, and achieve "timely response". In the existing compressed air energy storage system, the compressor start-stop process has the following problems: the traditional multi-stage compressor adopts a series start-up method, and the previous stage compressor must reach 100% speed before starting the next stage, resulting in a waste of waiting time between stages (accounting for about 40% of the total start-up time), making it difficult to quickly respond to grid dispatching needs; when shutting down, the pipeline gas needs to be completely emptied, resulting in large energy loss (about 30%-40% of the stored energy is lost). Summary of the invention

[0004] In order to solve the problem that the traditional multi-stage compressor adopts the series starting mode in the existing compressed air energy storage system, resulting in the waste of waiting time between stages; at the same time, in order to solve the problem that the pipeline gas needs to be completely emptied when shutting down in the existing compressed air energy storage system, resulting in large energy loss. The present invention provides a multi-stage compressor start-stop control system and method for a compressed air energy storage power station, which can shorten the startup time, avoid the gas in the system from being discharged when shutting down, and reduce energy loss.

[0005] The technical solution adopted by the multi-stage compressor start-stop control system and method of the compressed air energy storage power station of the present invention is: A multi-stage compressor start-stop control system for a compressed air energy storage power station includes two sets of compressor units and an expansion unit connected to the compressor units. Each set of compressor units includes four compressors connected in series. An anti-surge valve and a vent valve are provided in parallel on the outlet side of each compressor. The adjacent two-stage compressors are connected via a check valve, a butterfly valve shut-off valve, an energy storage heat exchanger and an aftercooler. At the same time, an aftercooler, a gas-liquid separator and an air injection valve are provided on the outlet side of the last compressor in each compressor unit. The expansion unit and the compressor unit form a switchable gas circuit coupling through an electric shut-off valve.

[0006] A further improvement of the technical solution of the present invention is that: a compressor unit includes a #1 compressor, a #2 compressor, a #3 compressor and a #4 compressor, the outlet side of the #1 compressor is provided with a first vent valve and a second vent valve in parallel, and the rear sides of the first vent valve and the second vent valve are connected to the inlet side of the #2 compressor in sequence through a first check valve, a first butterfly valve shut-off valve, a first energy storage heat exchanger, a second butterfly valve shut-off valve, a first aftercooler, a gas-liquid separator and a third butterfly valve shut-off valve; the outlet side of the #2 compressor is provided with a first anti-surge valve and a third vent valve in parallel, and the rear sides of the first anti-surge valve and the third vent valve are connected to the inlet side of the #3 compressor in sequence through a second check valve, a fourth butterfly valve shut-off valve, a second energy storage heat exchanger, a fifth butterfly valve shut-off valve, a second aftercooler, a gas-liquid separator and a sixth butterfly valve shut-off valve; the outlet side of the #3 compressor is provided with a second anti-surge valve and a fourth vent valve in parallel, and the second anti-surge valve and the fourth vent valve are connected to the inlet side of the #3 compressor in sequence. The rear side of the valve is connected to the inlet side of the #4 compressor through the third check valve, the third energy storage heat exchanger, the third aftercooler, the gas-liquid separator, the seventh butterfly valve shut-off valve and the fourth check valve in sequence; the outlet side of the #4 compressor is provided with the eighth butterfly valve shut-off valve, the fourth aftercooler, the gas-liquid separator, the fifth check valve and the first gas injection valve in sequence; wherein, the third anti-surge valve connected to the inlet side of the #4 compressor is provided in parallel between the gas-liquid separator and the fifth check valve on the outlet side of the #4 compressor, and the fifth vent valve and the first circulation valve are provided in parallel between the fifth check valve and the first gas injection valve; the valve back pressure of the first vent valve, the second vent valve, the third vent valve, the fourth vent valve and the fifth vent valve is set to atmospheric pressure, and the vent pipes after the first vent valve and the second vent valve are merged into the vent main pipe, and the vent pipes after the third vent valve, the fourth vent valve and the fifth vent valve are all connected to the vent main pipe.

[0007] A further improvement of the above technical solution of the present invention is that: another compressor unit includes a #5 compressor, a #6 compressor, a #7 compressor and a #8 compressor, and a sixth vent valve and a seventh vent valve are arranged in parallel on the outlet side of the #5 compressor, and the rear sides of the sixth vent valve and the seventh vent valve are connected to the inlet side of the #6 compressor through the sixth check valve, the ninth butterfly valve shut-off valve, the fourth energy storage heat exchanger, the tenth butterfly valve shut-off valve, the fifth aftercooler, the gas-liquid separator and the eleventh butterfly valve shut-off valve in sequence; a fourth anti-surge valve and an eighth vent valve are arranged in parallel on the outlet side of the #6 compressor, and the rear sides of the fourth anti-surge valve and the eighth vent valve are connected to the inlet side of the #7 compressor through the seventh check valve, the twelfth butterfly valve shut-off valve, the fifth energy storage heat exchanger, the thirteenth butterfly valve shut-off valve, the sixth aftercooler, the gas-liquid separator and the fourteenth butterfly valve shut-off valve in sequence; a fifth anti-surge valve and a ninth vent valve are arranged in parallel on the outlet side of the #7 compressor, and the rear sides of the fifth anti-surge valve and the ninth vent valve are connected to the inlet side of the #7 compressor through the eighth check valve, the twelfth butterfly valve shut-off valve, the fifth energy storage heat exchanger, the thirteenth butterfly valve shut-off valve, the sixth aftercooler, the gas-liquid separator and the fourteenth butterfly valve shut-off valve in sequence The sixth anti-surge valve, the sixth energy storage heat exchanger, the seventh aftercooler, the gas-liquid separator, the fifteenth butterfly valve shut-off valve and the ninth check valve are connected to the inlet side of the #8 compressor; the outlet side of the #8 compressor is sequentially provided with the sixteenth butterfly valve shut-off valve, the eighth aftercooler, the gas-liquid separator, the tenth check valve and the second gas injection valve; among them, the sixth anti-surge valve connected to the inlet side of the #8 compressor is arranged in parallel between the gas-liquid separator and the tenth check valve on the outlet side of the #8 compressor, and the tenth check valve and the second gas injection valve are arranged between the tenth check valve and the second gas injection valve. A tenth vent valve and a second circulation valve are arranged in parallel; a first ball valve shut-off valve is arranged on the mother pipe after the rear sides of the first gas injection valve and the second gas injection valve are merged; the back pressure behind the sixth vent valve, the seventh vent valve, the eighth vent valve, the ninth vent valve and the tenth vent valve is set to atmospheric pressure, and the vent pipes after the sixth vent valve and the seventh vent valve are merged into the vent mother pipe, and the vent pipes after the eighth vent valve, the ninth vent valve and the tenth vent valve are all connected to the vent mother pipe.

[0008] A further improvement of the above technical solution of the present invention is that: the expansion unit energy storage side main pipe is provided with a second ball valve shut-off valve connected in series with the first ball valve shut-off valve, the rear side of the second ball valve shut-off valve is connected in parallel with an eleventh vent valve, a first energy releasing heat exchanger and a second energy releasing heat exchanger, the first energy releasing heat exchanger is connected to the inlet of the high-pressure cylinder of the expansion unit through the first pneumatic shut-off valve, the second energy releasing heat exchanger is connected to the inlet of the high-pressure cylinder of the expansion unit through the second pneumatic shut-off valve, the outlet of the high-pressure cylinder is connected in parallel with a third pneumatic shut-off valve and a fourth pneumatic shut-off valve, the rear sides of the third pneumatic shut-off valve and the fourth pneumatic shut-off valve are merged and then connected to the compressor unit through the first electric shut-off valve and the second electric shut-off valve connected in parallel; the inlet of the medium-pressure cylinder of the expansion unit is connected in parallel with a fifth pneumatic shut-off valve and a sixth pneumatic shut-off valve, the fifth pneumatic shut-off valve A twelfth vent valve is connected in parallel between the sixth pneumatic shut-off valve and the medium-pressure cylinder, a thirteenth vent valve is connected in parallel between the sixth pneumatic shut-off valve and the medium-pressure cylinder, and the fifth pneumatic shut-off valve and the sixth pneumatic shut-off valve are connected to the compressor unit through the third electric shut-off valve and the fourth electric shut-off valve in parallel after the rear sides of the fifth pneumatic shut-off valve and the sixth pneumatic shut-off valve are merged; a seventh pneumatic shut-off valve and an eighth pneumatic shut-off valve are connected in parallel to the outlet of the medium-pressure cylinder, and the seventh pneumatic shut-off valve and the eighth pneumatic shut-off valve are connected to the compressor unit through the fifth electric shut-off valve and the sixth electric shut-off valve in parallel after the rear sides of the seventh pneumatic shut-off valve and the eighth pneumatic shut-off valve are merged; a ninth pneumatic shut-off valve and a fourteenth vent valve are connected in parallel on the inlet side of the low-pressure cylinder of the expansion unit, and the fourteenth vent valve is connected to the compressor unit through the seventh electric shut-off valve and the eighth electric shut-off valve in parallel, and an eleventh pneumatic shut-off valve is arranged on the outlet side of the low-pressure cylinder.

[0009] A method for starting and stopping a multi-stage compressor of a compressed air energy storage power station uses the above-mentioned multi-stage compressor start and stop control system of a compressed air energy storage power station, including compressor unit start-up, compressor unit shutdown, expansion unit start-up, expansion unit shutdown, compressor unit emergency shutdown under accident conditions, and expansion unit emergency shutdown under accident conditions.

[0010] A further improvement of the above technical solution of the present invention is that: when the compressor unit is started, the first electric shut-off valve and the second electric shut-off valve at the outlet of the high-pressure cylinder of the expansion unit, the third electric shut-off valve and the fourth electric shut-off valve at the outlet of the medium-pressure cylinder are closed, and all the compressor inlet and outlet shut-off valves are kept closed; first start the #1 compressor and the #5 compressor, and when the speed of the #1 compressor and the #5 compressor reaches 20% of the rated speed, open the first butterfly valve shut-off valve and the ninth butterfly valve shut-off valve, and when the speed of the #1 compressor and the #5 compressor reaches 35% of the rated speed, open the second butterfly valve shut-off valve and the tenth butterfly valve shut-off valve, and when the #1 compressor and the #5 compressor reach 40% of the rated speed, open the third butterfly valve shut-off valve and the eleventh butterfly valve shut-off valve, and start the #2 compressor and the #6 compressor at the same time, and when the speed of the #2 compressor and the #6 compressor reaches 30% of the rated speed, open the fourth butterfly valve shut-off valve and the twelfth butterfly valve shut-off valve, and when the speed of the #2 compressor and the #6 compressor reaches 45% of the rated speed, Open the fifth butterfly valve and the thirteenth butterfly valve, and when the speed of the #2 compressor and the #6 compressor reaches 50% of the rated speed, open the sixth butterfly valve and the fourteenth butterfly valve, and start the #3 compressor and the #7 compressor at the same time. When the speed of the #3 compressor and the #7 compressor reaches 65%, open the seventh butterfly valve and the fifteenth butterfly valve, and start the #4 compressor and the #8 compressor at the same time. When the speed of the #4 compressor and the #8 compressor reaches 30%, open the eighth butterfly valve and the sixteenth butterfly valve, and open the first circulation valve and the second circulation valve at the same time. When the speed of the #4 compressor and the #8 compressor reaches 95%, close the first circulation valve and the second circulation valve, open the first gas injection valve and the second gas injection valve, and when the speed of the #4 compressor and the #8 compressor reaches 100%, at the same time, the speed of the #1 compressor and the #5 compressor, the #2 compressor and the #6 compressor, the #3 compressor and the #7 compressor reaches 100%, open the first ball valve to inject gas into the gas storage reservoir.

[0011] A further improvement of the above technical solution of the present invention is that: when the compressor unit is shut down, the first ball valve shut-off valve is closed, the first circulation valve and the second circulation valve are opened, the speed of the #4 compressor and the #8 compressor is reduced, and when the speed of the #4 compressor and the #8 compressor is reduced to 75%, the first circulation valve and the second circulation valve are closed, the seventh butterfly valve shut-off valve and the fifteenth butterfly valve shut-off valve are closed, the third anti-surge valve and the sixth anti-surge valve are opened, the first air injection valve and the second air injection valve are closed, the second anti-surge valve and the fifth anti-surge valve are opened, and the speed of the #3 compressor and the #7 compressor is reduced. When the speed of the #3 compressor and the #7 compressor is reduced to 65%, the sixth butterfly valve shut-off valve and the fourteenth butterfly valve shut-off valve are closed, the fifth butterfly valve shut-off valve and the thirteenth butterfly valve shut-off valve are closed, the first anti-surge valve and the fourth anti-surge valve are opened, and the speed of the #2 compressor is reduced. Reduce the speed of #1 compressor and #5 compressor. When the speed of #2 compressor and #6 compressor is reduced to 55%, close the third butterfly valve and the eleventh butterfly valve, close the second butterfly valve and the tenth butterfly valve, close the first butterfly valve and the ninth butterfly valve, open the first vent valve, the second vent valve, the sixth vent valve and the seventh vent valve, reduce the speed of #1 compressor and #5 compressor. When the speed of #1 compressor and #5 compressor is about to reach the shutdown speed, close the first vent valve, the second vent valve, the sixth vent valve and the seventh vent valve. At the same time, the speed of #2 compressor and #6 compressor, #3 compressor and #7 compressor, #4 compressor and #8 compressor reaches the shutdown speed, close the eighth butterfly valve and the sixteenth butterfly valve, close all anti-surge valves, and shut down all compressors.

[0012] A further improvement of the above technical solution of the present invention is that: when the expansion unit is started, the first ball valve shut-off valve is closed, all inlet and outlet shut-off valves of the compressor are closed, the eleventh pneumatic shut-off valve is closed, the ninth pneumatic shut-off valve of the low-pressure cylinder is opened, the seventh electric shut-off valve and the eighth electric shut-off valve are opened, the second butterfly valve shut-off valve and the tenth butterfly valve shut-off valve are opened, and when the pressure of the low-pressure cylinder reaches 60% of the rated pressure, the second butterfly valve shut-off valve and the tenth butterfly valve shut-off valve are closed, the fifth pneumatic shut-off valve and the sixth pneumatic shut-off valve at the inlet of the medium-pressure cylinder are opened, the third electric shut-off valve and the fourth electric shut-off valve are opened, the fifth butterfly valve shut-off valve and the tenth butterfly valve shut-off valve are opened. Thirteen butterfly valve shut-off valves, when the pressure of the intermediate pressure cylinder reaches 50% of the rated pressure, close the fifth butterfly valve shut-off valve and the thirteenth butterfly valve shut-off valve, open the seventh pneumatic shut-off valve and the eighth pneumatic shut-off valve at the outlet of the intermediate pressure cylinder, open the fifth electric shut-off valve and the sixth electric shut-off valve, open the second ball valve shut-off valve, open the first pneumatic shut-off valve and the second pneumatic shut-off valve at the inlet of the high-pressure cylinder, when the pressure of the high-pressure cylinder reaches 40% of the rated pressure, open the third pneumatic shut-off valve and the fourth pneumatic shut-off valve at the outlet of the high-pressure cylinder, and when the high-pressure cylinder, the intermediate pressure cylinder, and the low-pressure cylinder all reach the rated pressure, open the eleventh pneumatic shut-off valve, and the start-up of the expansion unit is completed.

[0013] A further improvement of the above technical solution of the present invention is that: when the expansion unit is shut down, the fifth butterfly valve and the thirteenth butterfly valve are opened, the second ball valve is closed, the eleventh pneumatic shut-off valve of the low-pressure cylinder is closed, and the opening of the first pneumatic shut-off valve and the second pneumatic shut-off valve at the inlet of the high-pressure cylinder is reduced. When the speed of the expander is reduced to 70% of the rated speed, the fifth butterfly valve and the thirteenth butterfly valve are closed, and the second butterfly valve and the tenth butterfly valve are opened. When the speed of the expander is reduced to 40% of the rated speed, the first pneumatic shut-off valve and the second pneumatic shut-off valve at the inlet of the high-pressure cylinder are closed, the second butterfly valve and the tenth butterfly valve are closed, and the eleventh pneumatic shut-off valve of the low-pressure cylinder is opened. When the speed of the expansion unit is reduced to the shutdown speed, the eleventh pneumatic shut-off valve is closed, and the expansion unit is shut down.

[0014] A further improvement of the above technical solution of the present invention is that: when the compressor unit needs to be shut down under the accident condition, the first gas injection valve and the second gas injection valve are closed, the first ball valve shut-off valve is closed, the first circulation valve and the second circulation valve are closed, the rear vent valve and the anti-surge valve of the compressor are fully opened, and after the compressor shutdown speed is reached, the butterfly valve shut-off valves of the compressor are closed, and the compressor unit is shut down; when the expansion unit needs to be shut down under the accident condition, the second ball valve shut-off valve is closed, the eleventh vent valve is opened, the third electric shut-off valve and the fourth electric shut-off valve are closed, the fifth pneumatic shut-off valve and the sixth pneumatic shut-off valve at the inlet of the medium-pressure cylinder are closed, the ninth pneumatic shut-off valve and the tenth pneumatic shut-off valve are closed, the ninth pneumatic shut-off valve at the inlet of the low-pressure cylinder is closed, the fourteenth vent valve is opened, and the eleventh pneumatic shut-off valve at the outlet of the low-pressure cylinder is closed. When the speed of the expansion unit is reduced to the shutdown speed, the vent valve is closed, the pneumatic shut-off valves and the electric shut-off valves of the expansion unit are closed, and the expansion unit is shut down.

[0015] Due to the adoption of the above technical solution, the technical advances achieved by the present invention include: The compressors at all levels of the present invention are flexibly arranged with shut-off valves, vent valves and check valves according to the compressor characteristics and system configuration; the compressor anti-surge system and the accident vent system are separately arranged, and the normal shutdown and the accident shutdown are separately arranged, so as to reduce the interference between the systems and improve the shutdown rate; the pressure difference before and after the last-stage compressor is the largest and the inertia is small, and a circulation valve and an injection valve are arranged after the last-stage compressor, and the compressor is quickly started and stopped through the circulation valve when starting and stopping; in the event of an accident, the gas in the pipeline is sequentially emptied through the vent valve to realize the rapid shutdown of the compressor.

[0016] In the present invention, shut-off valves are provided for each compressor stage. During normal shutdown, the gas after the compressor stage is returned to the front of the compressor stage through the anti-surge valve and stored in the heat exchanger and pipeline, thereby increasing the rate of reduction of the pressure difference before and after the compressor, accelerating the shutdown time, avoiding the discharge of gas in the system, and reducing energy loss. The shutdown time can be reduced by 20%-30%, and the shutdown energy consumption can be reduced by 70%-80%.

[0017] When starting the compressor of the present invention, the back pressure start-up is adjusted to the pressure start-up, and the back pressure established by the gas stored in the heat exchanger and the pipeline is used to reduce the rotational inertia of the compressor when starting, and the startup energy consumption is reduced by 40%-50%; when starting, the compressors of each stage are started sequentially, and when the compressor reaches a certain speed, the next stage compressor is started, and the anti-surge valve is opened. After the gas behind the next stage compressor flows back to the previous stage compressor stage, the back pressure of the previous stage compressor is accelerated. The compressors of each stage are not started at the same time, but are started at the same time, which can reduce the startup time by 50%-60%, and the startup time is only the startup time of the first stage compressor.

[0018] When the expander of the present invention is started, the gas stored in the heat exchanger and the pipeline is used to sequentially open the low-pressure cylinder, the medium-pressure cylinder and the high-pressure cylinder, gradually build up the expander pressure, and the low-pressure cylinder, the medium-pressure cylinder and the high-pressure cylinder are inflated step by step, and the expander speed is gradually increased to realize the start-up of the expander under pressure, which can reduce the start-up time by 30%-40% and reduce the start-up energy consumption by 20%-30%; when the expander is stopped, the outlet valves of each cylinder of the expander are closed to quickly reduce the front and rear pressure difference and reduce the downtime, and at the same time, the valve connected to the compression side is opened to store the gas in the compression side heat exchanger and the pipeline, thereby reducing the downtime energy consumption, and at the same time, the compressor start-up time is accelerated to reduce the compressor start-up energy consumption, which can reduce the downtime by 20%-30% and reduce the downtime energy consumption by 10%-20%.

[0019] The compressor and the expander of the present invention are flexibly switched through the shut-off valve, and the start-up and shutdown energies of the compressor and the expander can be stored and utilized with each other. The compressor and the expander are coupled, so that the overall start-up and shutdown time of the system is reduced by 40%-50%, and the overall energy consumption is reduced by 60-80%. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of a multi-stage compressor start-stop control system of a compressed air energy storage power station of the present invention.

[0021] In the attached figure: 1, first vent valve; 2, second vent valve; 3, first check valve; 4, first butterfly valve shut-off valve; 5, second butterfly valve shut-off valve; 6, third butterfly valve shut-off valve; 7, first anti-surge valve; 8, third vent valve; 9, second check valve; 10, fourth butterfly valve shut-off valve; 11. The fifth butterfly valve shut-off valve; 12. The sixth butterfly valve shut-off valve; 13. The second anti-surge valve; 14. The fourth vent valve; 15. The third check valve; 16. The seventh butterfly valve shut-off valve; 17. The fourth check valve; 18. The eighth butterfly valve shut-off valve; 19. The third anti-surge valve; 20. The fifth check valve; 21. The fifth vent valve; 22. The first circulation valve; 23. The first gas injection valve; 24. The first energy storage heat exchanger; 25. The first aftercooler; 26. The sixth vent valve; 27. The seventh vent valve; 28. The sixth check valve; 29. ​​The ninth butterfly valve shut-off valve; 30. The tenth butterfly valve shut-off valve; 31. The eleventh butterfly valve shut-off valve; 32. The fourth anti-surge valve; 33. The eighth vent valve; 34. The seventh check valve; 35. The twelfth butterfly valve shut-off valve; 36. The thirteenth butterfly valve shut-off valve; 37. The fourteenth butterfly valve shut-off valve; 38. The fifth anti-surge valve; 39. The ninth vent valve; 40. The eighth check valve; 41. The fifteenth butterfly valve shut-off valve; 42. The ninth check valve; 43. The sixteenth butterfly valve shut-off valve; 44. The sixth anti-surge valve; 45. The tenth check valve; 46. The tenth vent valve; 47. The second circulation valve; 48. The second air injection valve; 49. The first ball valve shut-off valve; 50. The second ball valve shut-off valve; 51. Eleventh vent valve; 52. First pneumatic shut-off valve; 53. Second pneumatic shut-off valve; 54. Third pneumatic shut-off valve; 55. Fourth pneumatic shut-off valve; 56. First electric shut-off valve; 57. Second electric shut-off valve; 58. Third electric shut-off valve; 59. Fourth electric shut-off valve; 60. Fifth pneumatic shut-off valve; 61, twelfth vent valve; 62, sixth pneumatic shut-off valve; 63, thirteenth vent valve; 64, seventh pneumatic shut-off valve; 65, eighth pneumatic shut-off valve; 66, fifth electric shut-off valve; 67, sixth electric shut-off valve; 68, seventh electric shut-off valve; 69, eighth electric shut-off valve; 70, ninth pneumatic shut-off valve; 71. Fourteenth vent valve; 72. Eleventh pneumatic shut-off valve; 73. Gas-liquid separator; 74. Second energy storage heat exchanger; 75. Second aftercooler; 76. Third energy storage heat exchanger; 77. Third aftercooler; 78. Fourth aftercooler; 79. Fourth energy storage heat exchanger; 80. Fifth aftercooler; 81. Fifth energy storage heat exchanger; 82. Sixth aftercooler; 83. Sixth energy storage heat exchanger; 84. Seventh aftercooler; 85. Eighth aftercooler; 86. First energy release heat exchanger; 87. Second energy release heat exchanger; 88. High-pressure cylinder; 89. Medium-pressure cylinder; 90. Low-pressure cylinder; 91. Gas storage; 92. #1 compressor; 93. #2 compressor; 94. #3 compressor; 95. #4 compressor; 96. #5 compressor; 97. #6 compressor; 98. #7 compressor; 99. #8 compressor. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the present invention more clear, the present invention is further described in detail below in combination with specific implementation methods and with reference to the accompanying drawings. In the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.

[0023] This embodiment provides a multi-stage compressor start-stop control system for a compressed air energy storage power station. Figure 1It can be seen that the system includes two compressor units and an expansion unit connected to the compressor units.

[0024] In this embodiment, each compressor unit includes four stages of compressors connected in series. Specifically, one compressor unit includes four stages of compressors #1 92, compressor #2 93, compressor #3 94 and compressor #4 95 connected in series. The outlet side of compressor #1 92 is provided with a first vent valve 1 and a second vent valve 2 in parallel. The rear sides of the first vent valve 1 and the second vent valve 2 are sequentially connected through a first check valve 3, a first butterfly valve shut-off valve 4, a first energy storage heat exchanger 24, a second butterfly valve shut-off valve 5, a first aftercooler 25, and a gas-liquid separator 73. The first anti-surge valve 7 and the third vent valve 8 are connected to the inlet side of the #2 compressor 93 in parallel on the outlet side of the #2 compressor 93, and the rear sides of the first anti-surge valve 7 and the third vent valve 8 are connected to the inlet side of the #3 compressor 94 in sequence through the second check valve 9, the fourth butterfly valve shut-off valve 10, the second energy storage heat exchanger 74, the fifth butterfly valve shut-off valve 11, the second aftercooler 75, the gas-liquid separator 73 and the sixth butterfly valve shut-off valve 12; the second anti-surge valve 13 and the fourth vent valve 8 are connected to the outlet side of the #3 compressor 94 in parallel. The rear sides of the air valve 14, the second anti-surge valve 13 and the fourth vent valve 14 are connected to the inlet side of the #4 compressor 95 through the third check valve 15, the third energy storage heat exchanger 76, the third aftercooler 77, the gas-liquid separator 73, the seventh butterfly valve shut-off valve 16 and the fourth check valve 17 in sequence; the outlet side of the #4 compressor 95 is provided with the eighth butterfly valve shut-off valve 18, the fourth aftercooler 78, the gas-liquid separator 73, the fifth check valve 20 and the first gas injection valve 23 in sequence; wherein, the gas-liquid separator and the fifth check valve 20 on the outlet side of the #4 compressor 95 A third anti-surge valve 19 connected to the inlet side of #4 compressor 95 is arranged in parallel between the fifth check valve 20 and the first gas injection valve 23, and a fifth vent valve 21 and a first circulation valve 22 are arranged in parallel between the fifth check valve 20 and the first gas injection valve 23; the valve rear back pressure of the first vent valve 1, the second vent valve 2, the third vent valve 8, the fourth vent valve 14 and the fifth vent valve 21 is set to atmospheric pressure, and the vent pipes after the first vent valve 1 and the second vent valve 2 are merged into the vent main pipe, and the vent pipes after the third vent valve 8, the fourth vent valve 14 and the fifth vent valve 21 are all connected to the vent main pipe.

[0025] In this embodiment, another compressor unit includes four stages of #5 compressor 96, #6 compressor 97, #7 compressor 98 and #8 compressor 99 connected in series. The outlet side of #5 compressor 96 is provided with a sixth vent valve 26 and a seventh vent valve 27 in parallel. The rear sides of the sixth vent valve 26 and the seventh vent valve 27 are connected to the inlet side of #6 compressor 97 through the sixth check valve 28, the ninth butterfly valve shut-off valve 29, the fourth energy storage heat exchanger 79, the tenth butterfly valve shut-off valve 30, the fifth aftercooler 80, the gas-liquid separator 73 and the eleventh butterfly valve shut-off valve 31 in sequence; The outlet side of the compressor 97 is provided with a fourth anti-surge valve 32 and an eighth vent valve 33 in parallel, and the rear sides of the fourth anti-surge valve 32 and the eighth vent valve 33 are connected to the inlet side of the compressor 98 through the seventh check valve 34, the twelfth butterfly valve shut-off valve 35, the fifth energy storage heat exchanger 81, the thirteenth butterfly valve shut-off valve 36, the sixth aftercooler 82, the gas-liquid separator 73 and the fourteenth butterfly valve shut-off valve 37 in sequence; the outlet side of the compressor 98 is provided with a fifth anti-surge valve 38 and a ninth vent valve 39 in parallel, and the rear sides of the fifth anti-surge valve 38 and the ninth vent valve 39 are connected to the inlet side of the compressor 98 through the seventh check valve 34, the twelfth butterfly valve shut-off valve 35, the fifth energy storage heat exchanger 81, the thirteenth butterfly valve shut-off valve 36, the sixth aftercooler 82, the gas-liquid separator 73 and the fourteenth butterfly valve shut-off valve 37 in sequence. The eighth check valve 40, the sixth energy storage heat exchanger 83, the seventh aftercooler 84, the gas-liquid separator 73, the fifteenth butterfly valve shut-off valve 41 and the ninth check valve 42 are connected to the inlet side of the #8 compressor 99; the outlet side of the #8 compressor 99 is provided with the sixteenth butterfly valve shut-off valve 43, the eighth aftercooler 85, the gas-liquid separator 73, the tenth check valve 45 and the second gas injection valve 48 in sequence; wherein, the sixth anti-surge valve 44 connected to the inlet side of the #8 compressor 99 is provided in parallel between the gas-liquid separator 73 and the tenth check valve 45 on the outlet side of the #8 compressor 99, and the tenth check valve 48 are provided in parallel. A tenth vent valve 46 and a second circulation valve 47 are arranged in parallel between the return valve 45 and the second gas injection valve 48; a first ball valve shut-off valve 49 is arranged on the mother pipe after the rear sides of the first gas injection valve 23 and the second gas injection valve 48 merge; the back pressure behind the sixth vent valve 26, the seventh vent valve 27, the eighth vent valve 33, the ninth vent valve 39 and the tenth vent valve 46 is set to atmospheric pressure, and the vent pipes after the sixth vent valve 26 and the seventh vent valve 27 are merged into the vent mother pipe, and at the same time, the vent pipes after the eighth vent valve 33, the ninth vent valve 39 and the tenth vent valve 46 are all connected to the vent mother pipe.

[0026] In this embodiment, the expansion unit includes a high-pressure cylinder 88, an intermediate-pressure cylinder 89 and a low-pressure cylinder 90. Specifically, the expansion unit energy storage side mother pipe is provided with a second ball valve shut-off valve 50 connected in series with the first ball valve shut-off valve 49. The rear side of the second ball valve shut-off valve 50 is connected in parallel with an eleventh vent valve 51, a first energy release heat exchanger 86 and a second energy release heat exchanger 87. The first energy release heat exchanger 86 is connected through a first pneumatic shut-off valve 52, and the second energy release heat exchanger 87 is connected through a second pneumatic shut-off valve 52. The shut-off valve 53 is connected to the inlet of the high-pressure cylinder 88 of the expansion unit. The outlet of the high-pressure cylinder 88 is connected in parallel with the third pneumatic shut-off valve 54 and the fourth pneumatic shut-off valve 55. The rear sides of the third pneumatic shut-off valve 54 and the fourth pneumatic shut-off valve 55 are connected to the compressor unit through the first electric shut-off valve 56 and the second electric shut-off valve 57 connected in parallel after the third pneumatic shut-off valve 54 and the fourth pneumatic shut-off valve 55 are merged. The inlet of the intermediate-pressure cylinder 89 of the expansion unit is connected in parallel with the fifth pneumatic shut-off valve 60 and the sixth pneumatic shut-off valve 62. A twelfth vent valve 61 is connected in parallel between the shut-off valve 60 and the medium-pressure cylinder 89, a thirteenth vent valve 63 is connected in parallel between the sixth pneumatic shut-off valve 62 and the medium-pressure cylinder 89, and the rear sides of the fifth pneumatic shut-off valve 60 and the sixth pneumatic shut-off valve 62 are connected to the compressor unit through the third electric shut-off valve 58 and the fourth electric shut-off valve 59 connected in parallel; the outlet of the medium-pressure cylinder 89 is connected in parallel with the seventh pneumatic shut-off valve 64 and the eighth pneumatic shut-off valve 65, and the seventh pneumatic shut-off valve 6 4 and the rear side of the eighth pneumatic shut-off valve 65 are connected to the compressor unit through the fifth electric shut-off valve 66 and the sixth electric shut-off valve 67 connected in parallel; the inlet side of the low-pressure cylinder 90 of the expansion unit is connected in parallel with the ninth pneumatic shut-off valve 70 and the fourteenth vent valve 71, the fourteenth vent valve 71 is connected to the compressor unit through the seventh electric shut-off valve 68 and the eighth electric shut-off valve 69 connected in parallel, and the outlet side of the low-pressure cylinder 90 is provided with the eleventh pneumatic shut-off valve 72.

[0027] In this embodiment, the first energy storage heat exchanger 24, the second energy storage heat exchanger 74, the fourth energy storage heat exchanger 79 and the fifth energy storage heat exchanger 81 all adopt the cross-flow heat exchanger commonly used in the prior art, and the third energy storage heat exchanger 76, the sixth energy storage heat exchanger 83, the first energy release heat exchanger 86 and the second energy release heat exchanger 87 all adopt the hairpin heat exchanger commonly used in the prior art; in this embodiment, the first aftercooler 25, the second aftercooler 75, the fifth aftercooler 80 and the sixth aftercooler 82 all adopt the cross-flow cooler commonly used in the prior art, and the third aftercooler 77, the fourth aftercooler 78, the seventh aftercooler 84 and the eighth aftercooler 85 all adopt the U-tube cooler commonly used in the prior art.

[0028] This embodiment also provides a multi-stage compressor start-stop control method for a compressed air energy storage power station, which includes compressor unit startup, compressor unit shutdown, expansion unit startup, expansion unit shutdown, compressor unit emergency shutdown under accident conditions, and expansion unit emergency shutdown under accident conditions.

[0029] Among them, when the compressor unit is started, the first electric shut-off valve 56 and the second electric shut-off valve 57 at the outlet of the high-pressure cylinder 88 of the expansion unit, the third electric shut-off valve 58 and the fourth electric shut-off valve 59 at the outlet of the medium-pressure cylinder 89 are closed, and all the compressor inlet and outlet shut-off valves are kept closed; first start the #1 compressor 92 and the #5 compressor 96, and when the speed of the #1 compressor 92 and the #5 compressor 96 reaches 20% of the rated speed, open the first butterfly valve shut-off valve 4 and the ninth butterfly valve shut-off valve 29, and when the speed of the #1 compressor 92 and the #5 compressor 96 reaches 35% of the rated speed, open the The second butterfly valve shut-off valve 5 and the tenth butterfly valve shut-off valve 30, when the #1 compressor 92 and the #5 compressor 96 reach 40% of the rated speed, open the third butterfly valve shut-off valve 6 and the eleventh butterfly valve shut-off valve 31, and start the #2 compressor 93 and the #6 compressor 97 at the same time, when the speed of the #2 compressor 93 and the #6 compressor 97 reaches 30% of the rated speed, open the fourth butterfly valve shut-off valve 10 and the twelfth butterfly valve shut-off valve 35, when the speed of the #2 compressor 93 and the #6 compressor 97 reaches 45% of the rated speed, open the fifth butterfly valve shut-off valve 11 and the thirteenth butterfly valve shut-off valve 36, when the speed of #2 compressor 93 and #6 compressor 97 reaches 50% of the rated speed, open the sixth butterfly valve shut-off valve 12 and the fourteenth butterfly valve shut-off valve 37, and start the #3 compressor 94 and #7 compressor 98 at the same time, when the speed of #3 compressor 94 and #7 compressor 98 reaches 65%, open the seventh butterfly valve shut-off valve 16 and the fifteenth butterfly valve shut-off valve 41, and start the #4 compressor 95 and #8 compressor 99 at the same time, when the speed of #4 compressor 95 and #8 compressor 99 reaches 30%, open the eighth butterfly valve shut-off valve 18 and the sixteenth butterfly valve shut-off valve 4 3. Open the first circulation valve 22 and the second circulation valve 47 at the same time. When the speeds of the #4 compressor 95 and the #8 compressor 99 reach 95%, close the first circulation valve 22 and the second circulation valve 47, open the first gas injection valve 23 and the second gas injection valve 48, and when the speeds of the #4 compressor 95 and the #8 compressor 99 reach 100%, at the same time, the speeds of the #1 compressor 92 and the #5 compressor 96, the #2 compressor 93 and the #6 compressor 97, the #3 compressor 94 and the #7 compressor 98 reach 100%, open the first ball valve shut-off valve 49 to inject gas into the gas storage reservoir 91.

[0030] In this embodiment, when the compressor unit is shut down, the first ball valve shut-off valve 49 is closed, the first circulation valve 22 and the second circulation valve 47 are opened, the speed of the #4 compressor 95 and the #8 compressor 99 is reduced, and when the speed of the #4 compressor 95 and the #8 compressor 99 is reduced to 75%, the first circulation valve 22 and the second circulation valve 47 are closed, the seventh butterfly valve shut-off valve 16 and the fifteenth butterfly valve shut-off valve 41 are closed, the third anti-surge valve 19 and the sixth anti-surge valve 44 are opened, the first gas injection valve 23 and the second gas injection valve 48 are closed, the second anti-surge valve 13 and the fifth anti-surge valve 38 are opened, and the speed of the #3 compressor 94 and the #7 compressor 98 is reduced. When the speed of the #3 compressor 94 and the #7 compressor 98 is reduced to 65%, the sixth butterfly valve shut-off valve 12 and the fourteenth butterfly valve shut-off valve 37 are closed, the fifth butterfly valve shut-off valve 11 and the thirteenth butterfly valve shut-off valve 36 are closed, the first anti-surge valve 7 and the fourth anti-surge valve 32 are opened, and the speed of the #2 compressor 93 and the #6 compressor is reduced. The speed of compressor 97 is reduced. When the speed of compressor #2 93 and compressor #6 97 is reduced to 55%, the third butterfly valve shut-off valve 6 and the eleventh butterfly valve shut-off valve 31 are closed, the second butterfly valve shut-off valve 5 and the tenth butterfly valve shut-off valve 30 are closed, the first butterfly valve shut-off valve 4 and the ninth butterfly valve shut-off valve 29 are closed, the first vent valve 1, the second vent valve 2, the sixth vent valve 26 and the seventh vent valve 27 are opened, and the speed of compressor #1 92 and compressor #5 96 is reduced. When the speed of compressor #1 92 and compressor #5 96 is about to reach the shutdown speed, the first vent valve 1, the second vent valve 2, the sixth vent valve 26 and the seventh vent valve 27 are closed. At the same time, the speed of compressor #2 93 and compressor #6 97, compressor #3 94 and compressor #7 98, compressor #4 95 and compressor #8 99 reaches the shutdown speed, the eighth butterfly valve shut-off valve 18 and the sixteenth butterfly valve shut-off valve 43 are closed, all anti-surge valves are closed, and all compressors are shut down.

[0031] In this embodiment, when the expansion unit is started, the first ball valve shut-off valve 49 is closed, all the inlet and outlet shut-off valves of the compressor are closed, the eleventh pneumatic shut-off valve 72 is closed, the ninth pneumatic shut-off valve 70 of the low-pressure cylinder is opened, the seventh electric shut-off valve 68 and the eighth electric shut-off valve 69 are opened, the second butterfly valve shut-off valve 5 and the tenth butterfly valve shut-off valve 30 are opened, and when the pressure of the low-pressure cylinder 90 reaches 60% of the rated pressure, the second butterfly valve shut-off valve 5 and the tenth butterfly valve shut-off valve 30 are closed, the fifth pneumatic shut-off valve 60 and the sixth pneumatic shut-off valve 62 at the inlet of the medium-pressure cylinder 89 are opened, the third electric shut-off valve 58 and the fourth electric shut-off valve 59 are opened, the fifth butterfly valve shut-off valve 11 and the thirteenth butterfly valve shut-off valve 36 are opened, and the medium-pressure cylinder 89 is opened. When the pressure of cylinder 89 reaches 50% of the rated pressure, close the fifth butterfly valve shut-off valve 11 and the thirteenth butterfly valve shut-off valve 36, open the seventh pneumatic shut-off valve 64 and the eighth pneumatic shut-off valve 65 at the outlet of the medium-pressure cylinder 89, open the fifth electric shut-off valve 66 and the sixth electric shut-off valve 67, open the second ball valve shut-off valve 50, open the first pneumatic shut-off valve 52 and the second pneumatic shut-off valve 53 at the inlet of the high-pressure cylinder 88, and when the pressure of the high-pressure cylinder 88 reaches 40% of the rated pressure, open the third pneumatic shut-off valve 54 and the fourth pneumatic shut-off valve 55 at the outlet of the high-pressure cylinder 88, and when the high-pressure cylinder 88, the medium-pressure cylinder 89, and the low-pressure cylinder 90 all reach the rated pressure, open the eleventh pneumatic shut-off valve 72, and the start-up of the expansion unit is completed.

[0032] In this embodiment, when the expansion unit is shut down, the fifth butterfly valve shut-off valve 11 and the thirteenth butterfly valve shut-off valve 36 are opened, the second ball valve shut-off valve 50 is closed, the eleventh pneumatic shut-off valve 72 of the low-pressure cylinder 90 is closed, and the opening of the first pneumatic shut-off valve 52 and the second pneumatic shut-off valve 53 at the inlet of the high-pressure cylinder 88 is reduced. When the speed of the expander is reduced to 70% of the rated speed, the fifth butterfly valve shut-off valve 11 and the thirteenth butterfly valve shut-off valve 36 are closed, the second butterfly valve shut-off valve 5 and the tenth butterfly valve shut-off valve 30 are opened, and when the speed of the expander is reduced to 40% of the rated speed, the first pneumatic shut-off valve 52 and the second pneumatic shut-off valve 53 at the inlet of the high-pressure cylinder 88 are closed, the second butterfly valve shut-off valve 5 and the tenth butterfly valve shut-off valve 30 are closed, and the eleventh pneumatic shut-off valve 72 of the low-pressure cylinder 90 is opened. When the speed of the expansion unit is reduced to the shutdown speed, the eleventh pneumatic shut-off valve 72 is closed, and the expansion unit is shut down.

[0033] When an accident occurs during the use of the system of this embodiment, the compressor unit needs to be shut down urgently. Specifically, the first gas injection valve 23 and the second gas injection valve 48 are closed, the first ball valve shut-off valve 49 is closed, the first circulation valve 22 and the second circulation valve 47 are closed, the exhaust valve and the anti-surge valve after the compressor are fully opened, and after the compressor reaches the shutdown speed, the compressor butterfly valve shut-off valves are closed, and the compressor unit is shut down; at the same time, the expansion unit is shut down urgently, the second ball valve shut-off valve 50 is closed, the eleventh exhaust valve 51 is opened, and the third electric The shut-off valve 58 and the fourth electric shut-off valve 59 close the fifth pneumatic shut-off valve 60 and the sixth pneumatic shut-off valve 62 at the inlet of the medium-pressure cylinder 89, close the ninth pneumatic shut-off valve 68 and the tenth pneumatic shut-off valve 69, close the ninth pneumatic shut-off valve 70 at the inlet of the low-pressure cylinder 90, open the fourteenth vent valve 71, and close the eleventh pneumatic shut-off valve 72 at the outlet of the low-pressure cylinder 90. When the speed of the expansion unit is reduced to the shutdown speed, close the vent valve, close the pneumatic shut-off valves and the electric shut-off valves of the expansion unit, and shut down the expansion unit.

[0034] Taking the 300MW compressed air energy storage power station as an example, the compressor is arranged in two lines and four sections, and the expander has two-stage reheating and three-stage expansion. The compressor startup time can be reduced from 20min to 10min, and the shutdown time can be reduced from 15min to 8min, and the compressor startup and shutdown power consumption can be reduced by 60%; the expander startup time can be reduced from 15min to 10min, and the shutdown time can be reduced from 12min to 10min, and the expander startup and shutdown power consumption can be reduced by 40%.

[0035] In the above embodiment, the present invention provides a multi-stage compressor start-stop control system and method for a compressed air energy storage power station. The compressors at each stage of the present invention are flexibly arranged with shut-off valves, vent valves, and check valves according to the compressor characteristics and system configuration; the compressor anti-surge system and the accident vent system are separately arranged, and the normal shutdown and the accident shutdown are separately arranged to reduce interference between systems and improve the shutdown rate; the pressure difference before and after the last-stage compressor is the largest and the inertia is small. A circulation valve and an injection valve are arranged after the last-stage compressor, and the compressor is quickly started and stopped through the circulation valve when starting and stopping; in an accident condition, the gas in the pipeline is sequentially emptied through the vent valve to realize the rapid shutdown of the compressor; the compressor and the expander of the present invention are flexibly switched through the shut-off valve, and the start-stop energy of the compressor and the expander can be stored and utilized by each other, and the compressor and the expander are coupled, so that the overall start-stop time of the system is reduced by 40%-50%, and the overall energy consumption is reduced by 60-80%.

[0036] The above-described embodiments are merely descriptions of preferred implementations of the present invention, and are not intended to limit the concept and scope of the present invention. Without departing from the design concept of the present invention, various modifications and improvements made by ordinary persons in the art to the technical solution of the present invention should fall within the protection scope of the present invention, and the technical contents for which protection is sought in the present invention have been fully recorded in the claims.

Claims

1. A multi-stage compressor start-stop control system for a compressed air energy storage power station, comprising two compressor units and an expansion unit connected to the compressor units, characterized in that: Each compressor unit includes four compressors connected in series. The outlet side of each compressor is provided with an anti-surge valve and a vent valve in parallel, and the adjacent two compressors are connected through a check valve, a butterfly valve shut-off valve, an energy storage heat exchanger and an aftercooler. At the same time, the outlet side of the last compressor in each compressor unit is provided with an aftercooler, a gas-liquid separator and an air injection valve. The expansion unit and the compressor unit form a switchable gas circuit coupling through an electric shut-off valve.

2. A multi-stage compressor start-stop control system for a compressed air energy storage power station according to claim 1, characterized in that: A compressor unit comprises a #1 compressor (92), a #2 compressor (93), a #3 compressor (94) and a #4 compressor (95), wherein a first vent valve (1) and a second vent valve (2) are arranged in parallel on the outlet side of the #1 compressor (92), and the rear sides of the first vent valve (1) and the second vent valve (2) are connected to the #2 compressor (93) via a first check valve (3), a first butterfly valve shut-off valve (4), a first energy storage heat exchanger (24), a second butterfly valve shut-off valve (5), a first aftercooler (25), a gas-liquid separator (73) and a third butterfly valve shut-off valve (6) in sequence. The inlet sides of the #4 compressor (95) are connected; the connection mode between the #2 compressor (93) and the #1 compressor (92), and the connection mode between the #3 compressor (94) and the #2 compressor (93) is the same as the connection mode between the #1 compressor (92) and the #2 compressor (93); wherein a third anti-surge valve (19) connected to the inlet side of the #4 compressor is arranged in parallel between the gas-liquid separator (73) on the outlet side of the #4 compressor (95) and the fifth check valve (20), and a fifth vent valve (21) and a first circulation valve (22) are arranged in parallel between the fifth check valve (20) and the first gas injection valve (23).

3. A multi-stage compressor start-stop control system for a compressed air energy storage power station according to claim 2, characterized in that: Another compressor unit comprises a #5 compressor (96), a #6 compressor (97), a #7 compressor (98) and a #8 compressor (99). A sixth vent valve (26) and a seventh vent valve (27) are arranged in parallel on the outlet side of the #5 compressor (96). The rear sides of the sixth vent valve (26) and the seventh vent valve (27) are connected to the inlet side of the #6 compressor (97) via a sixth check valve (28), a ninth butterfly valve shut-off valve (29), a fourth energy storage heat exchanger (79), a tenth butterfly valve shut-off valve (30), a fifth aftercooler (80), a gas-liquid separator (73) and an eleventh butterfly valve shut-off valve (31) in sequence. The #6 compressor (97) and the #8 compressor (99) are connected to the #9 compressor (96). The connection mode between the #7 compressor (98), the #7 compressor (98) and the #8 compressor (99) is the same as the connection mode between the #5 compressor (92) and the #6 compressor (93); wherein a sixth anti-surge valve (44) connected to the inlet side of the #8 compressor (99) is arranged in parallel between the gas-liquid separator (73) on the outlet side of the #8 compressor (99) and the tenth check valve (45); a tenth vent valve (46) and a second circulation valve (47) are arranged in parallel between the tenth check valve (45) and the second gas injection valve (48); and a first ball valve shut-off valve (49) is arranged on the mother pipe after the rear sides of the first gas injection valve (23) and the second gas injection valve (48) are joined.

4. A multi-stage compressor start-stop control system for a compressed air energy storage power station according to claim 3, characterized in that: The energy storage side main pipe of the expansion unit is provided with a second ball valve shut-off valve (50) connected in series with the first ball valve shut-off valve (49); the rear side of the second ball valve shut-off valve (50) is connected in parallel with an eleventh vent valve (51), a first energy release heat exchanger (86) and a second energy release heat exchanger (87); the first energy release heat exchanger (86) is connected to the inlet of the high-pressure cylinder (88) of the expansion unit through the first pneumatic shut-off valve (52); the second energy release heat exchanger (87) is connected to the inlet of the high-pressure cylinder (88) of the expansion unit through the second pneumatic shut-off valve (53); The outlet of the expansion unit (88) is connected in parallel with a third pneumatic shut-off valve (54) and a fourth pneumatic shut-off valve (55); the rear sides of the third pneumatic shut-off valve (54) and the fourth pneumatic shut-off valve (55) are connected to the compressor unit through a first electric shut-off valve (56) and a second electric shut-off valve (57) connected in parallel; the inlet of the intermediate pressure cylinder (89) of the expansion unit is connected in parallel with a fifth pneumatic shut-off valve (60) and a sixth pneumatic shut-off valve (62); a fifth pneumatic shut-off valve (60) and a sixth pneumatic shut-off valve (62) are connected in parallel between the fifth pneumatic shut-off valve (60) and the intermediate pressure cylinder (89); A thirteenth vent valve (63) is connected in parallel between the twelfth vent valve (61), the sixth pneumatic shut-off valve (62) and the medium-pressure cylinder (89); the rear sides of the fifth pneumatic shut-off valve (60) and the sixth pneumatic shut-off valve (62) are connected to the compressor unit through the third electric shut-off valve (58) and the fourth electric shut-off valve (59) connected in parallel; the outlet of the medium-pressure cylinder (89) is connected in parallel with a seventh pneumatic shut-off valve (64) and an eighth pneumatic shut-off valve (65); the seventh pneumatic shut-off valve (64) and the eighth pneumatic shut-off valve (65) are connected in parallel with each other; The rear sides of the shut-off valves (65) are connected to the compressor unit through a fifth electric shut-off valve (66) and a sixth electric shut-off valve (67) connected in parallel. A ninth pneumatic shut-off valve (70) and a fourteenth vent valve (71) are connected in parallel to the inlet side of the low-pressure cylinder (90) of the expansion unit. The fourteenth vent valve (71) is connected to the compressor unit through a seventh electric shut-off valve (68) and an eighth electric shut-off valve (69) connected in parallel. An eleventh pneumatic shut-off valve (72) is provided on the outlet side of the low-pressure cylinder (90).

5. A method for starting and stopping a multi-stage compressor of a compressed air energy storage power station, characterized in that: A compressed air energy storage power station multi-stage compressor start-stop control system using any one of claims 1-4 includes compressor unit start-up, compressor unit shutdown, expansion unit start-up, expansion unit shutdown, compressor unit emergency shutdown under accident conditions, and expansion unit emergency shutdown under accident conditions.

6. A method for starting and stopping a multi-stage compressor of a compressed air energy storage power station according to claim 5, characterized in that: When the compressor unit is started, the first electric shut-off valve (56) and the second electric shut-off valve (57) at the outlet of the high-pressure cylinder (88) of the expansion unit, the third electric shut-off valve (58) and the fourth electric shut-off valve (59) at the outlet of the medium-pressure cylinder (89) are closed, and all the compressor inlet and outlet shut-off valves are kept closed; the #1 compressor and the #5 compressor are started first, and when the speeds of the #1 compressor and the #5 compressor reach 20% of the rated speed, the first butterfly valve (4) and the ninth butterfly valve (29) are opened, and when the speeds of the #1 compressor and the #5 compressor reach 30% of the rated speed, the compressor is shut off. When the speed of compressor #1 and compressor #5 reaches 40% of the rated speed, the third butterfly valve (6) and the eleventh butterfly valve (31) are opened, and compressor #2 and compressor #6 are started at the same time. When the speed of compressor #2 and compressor #6 reaches 30% of the rated speed, the fourth butterfly valve (10) and the twelfth butterfly valve (35) are opened. When the speed of compressor #2 and compressor #6 reaches 45% of the rated speed, the fifth butterfly valve (11) and the fifth butterfly valve (12) are opened. The thirteenth butterfly valve shut-off valve (36) opens the sixth butterfly valve shut-off valve (12) and the fourteenth butterfly valve shut-off valve (37) when the speeds of the #2 compressor and the #6 compressor reach 50% of the rated speed, and simultaneously starts the #3 compressor and the #7 compressor. When the speeds of the #3 compressor and the #7 compressor reach 65%, the seventh butterfly valve shut-off valve (16) and the fifteenth butterfly valve shut-off valve (41) are opened, and simultaneously starts the #4 compressor and the #8 compressor. When the speeds of the #4 compressor and the #8 compressor reach 30%, the eighth butterfly valve shut-off valve (18) and the sixteenth butterfly valve shut-off valve are opened. (43), the first circulation valve (22) and the second circulation valve (47) are opened at the same time, and when the rotation speeds of the #4 compressor and the #8 compressor reach 95%, the first circulation valve (22) and the second circulation valve (47) are closed, and the first gas injection valve (23) and the second gas injection valve (48) are opened, and when the rotation speeds of the #4 compressor and the #8 compressor reach 100%, at the same time, the rotation speeds of the #1 compressor and the #5 compressor, the #2 compressor and the #6 compressor, the #3 compressor and the #7 compressor reach 100%, the first ball valve shut-off valve (49) is opened to inject gas into the gas storage reservoir (91).

7. A method for starting and stopping a multi-stage compressor of a compressed air energy storage power station according to claim 5, characterized in that: When the compressor unit is shut down, the first ball valve shutoff valve (49) is closed, the first circulation valve (22) and the second circulation valve (47) are opened, the rotation speeds of the #4 compressor and the #8 compressor are reduced, and when the rotation speeds of the #4 compressor and the #8 compressor are reduced to 75%, the first circulation valve (22) and the second circulation valve (47) are closed, the seventh butterfly valve shutoff valve (16) and the fifteenth butterfly valve shutoff valve (41) are closed, the third anti-surge valve (19) and the sixth anti-surge valve (44) are opened, the first air injection valve (23) and the second air injection valve (48) are closed, the second anti-surge valve (13) and the fifth anti-surge valve (38) are opened, the rotation speeds of the #3 compressor and the #7 compressor are reduced, and when the rotation speeds of the #3 compressor and the #7 compressor are reduced to 65%, the sixth butterfly valve shutoff valve (12) and the fourteenth butterfly valve shutoff valve (37) are closed, the fifth butterfly valve shutoff valve (11) and the thirteenth butterfly valve shutoff valve (36) are closed, the first anti-surge valve (7) and the fourth anti-surge valve (32) are opened, and the rotation speeds of the #2 compressor and the #7 compressor are reduced. The speed of the compressor #1 and #5 is reduced. When the speed of the compressor #2 and #6 is reduced to 55%, the third butterfly valve (6) and the eleventh butterfly valve (31) are closed, the second butterfly valve (5) and the tenth butterfly valve (30) are closed, the first butterfly valve (4) and the ninth butterfly valve (29) are closed, the first vent valve (1), the second vent valve (2), the sixth vent valve (26) and the seventh vent valve (27) are opened, and the speed of the compressor #1 and #5 is reduced. When the speed of the compressor #1 and #5 reaches the shutdown speed, the first vent valve (1), the second vent valve (2), the sixth vent valve (26) and the seventh vent valve (27) are closed. At the same time, the speed of the compressor #2 and #6, the compressor #3 and #7, the compressor #4 and #8 reaches the shutdown speed, the eighth butterfly valve (18) and the sixteenth butterfly valve (43) are closed, all anti-surge valves are closed, and all compressors are shut down.

8. A method for starting and stopping a multi-stage compressor of a compressed air energy storage power station according to claim 5, characterized in that: When the expansion unit is started, the first ball valve (49) is closed, all the compressor inlet and outlet valves are closed, the eleventh pneumatic shut-off valve (72) is closed, the ninth pneumatic shut-off valve (70) of the low-pressure cylinder is opened, the seventh electric shut-off valve (68) and the eighth electric shut-off valve (69) are opened, the second butterfly valve (5) and the tenth butterfly valve (30) are opened, and when the pressure of the low-pressure cylinder (90) reaches 60% of the rated pressure, the second butterfly valve (5) and the tenth butterfly valve (30) are closed, the fifth pneumatic shut-off valve (60) and the sixth pneumatic shut-off valve (62) at the inlet of the medium-pressure cylinder (89) are opened, the third electric shut-off valve (58) and the fourth electric shut-off valve (59) are opened, the fifth butterfly valve (11) and the thirteenth butterfly valve (36) are opened, and the medium-pressure cylinder (89) When the pressure reaches 50% of the rated pressure, the fifth butterfly valve shut-off valve (11) and the thirteenth butterfly valve shut-off valve (36) are closed, the seventh pneumatic shut-off valve (64) and the eighth pneumatic shut-off valve (65) at the outlet of the medium-pressure cylinder (89) are opened, the fifth electric shut-off valve (66) and the sixth electric shut-off valve (67) are opened, the second ball valve shut-off valve (50) is opened, and the first pneumatic shut-off valve (52) and the second pneumatic shut-off valve (53) at the inlet of the high-pressure cylinder (88) are opened. When the pressure of the high-pressure cylinder (88) reaches 40% of the rated pressure, the third pneumatic shut-off valve (54) and the fourth pneumatic shut-off valve (55) at the outlet of the high-pressure cylinder (88) are opened. When the high-pressure cylinder (88), the medium-pressure cylinder (89) and the low-pressure cylinder (90) all reach the rated pressure, the eleventh pneumatic shut-off valve (72) is opened, and the start-up of the expansion unit is completed.

9. A method for starting and stopping a multi-stage compressor of a compressed air energy storage power station according to claim 5, characterized in that: When the expansion unit is shut down, the fifth butterfly valve (11) and the thirteenth butterfly valve (36) are opened, the second ball valve (50) is closed, the eleventh pneumatic shutoff valve (72) of the low-pressure cylinder (90) is closed, the opening of the first pneumatic shutoff valve (52) and the second pneumatic shutoff valve (53) at the inlet of the high-pressure cylinder (88) is reduced, and when the speed of the expansion unit is reduced to 70% of the rated speed, the fifth butterfly valve (11) and the thirteenth butterfly valve (36) are closed, and the second ball valve (50) is opened. The butterfly valve shut-off valve (5) and the tenth butterfly valve shut-off valve (30) are closed. When the speed of the expander is reduced to 40% of the rated speed, the first pneumatic shut-off valve (52) and the second pneumatic shut-off valve (53) at the inlet of the high-pressure cylinder (88) are closed. The second butterfly valve shut-off valve (5) and the tenth butterfly valve shut-off valve (30) are closed. The eleventh pneumatic shut-off valve (72) of the low-pressure cylinder (90) is opened. When the speed of the expander is reduced to the shutdown speed, the eleventh pneumatic shut-off valve (72) is closed, and the expander is shut down.

10. A method for starting and stopping a multi-stage compressor of a compressed air energy storage power station according to claim 5, characterized in that: When the compressor unit needs to be shut down under the accident condition, the first gas injection valve (23) and the second gas injection valve (48) are closed, the first ball valve shut-off valve (49) is closed, the first circulation valve (22) and the second circulation valve (47) are closed, the compressor rear vent valve and the anti-surge valve are fully opened, and after the compressor reaches the shutdown speed, the compressor butterfly valve shut-off valves are closed, and the compressor unit is shut down; when the expansion unit needs to be shut down under the accident condition, the second ball valve shut-off valve (50) is closed, the eleventh vent valve (51) is opened, and the third electric shut-off valve (58) and the fourth electric shut-off valve (59) are closed. The fifth pneumatic shut-off valve (59) at the inlet of the medium-pressure cylinder (89) is closed, the sixth pneumatic shut-off valve (60) and the ninth pneumatic shut-off valve (68) and the tenth pneumatic shut-off valve (69) are closed, the ninth pneumatic shut-off valve (70) at the inlet of the low-pressure cylinder (90) is closed, the fourteenth vent valve (71) is opened, and the eleventh pneumatic shut-off valve (72) at the outlet of the low-pressure cylinder (90) is closed. When the speed of the expansion unit is reduced to the shutdown speed, the vent valve is closed, and the pneumatic shut-off valves and the electric shut-off valve of the expansion unit are closed, and the expansion unit is shut down.

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