System and method for rapidly switching energy storage and release modes of large compressed air energy storage power station

Abstract

The invention relates to a system and a method for rapidly switching energy storage and release modes of a large compressed air energy storage power station. The system comprises a compressor unit, a compression side heat exchange system, a cooler, an expansion unit, an expansion side heat exchange system, a salt cavern, a low-temperature heat storage device, a high-temperature heat storage device, a switching valve, a high-temperature heat storage circulating pump, a low-temperature heat storage circulating pump, a stop valve, a motor and a generator. The compressor unit is connected to the salt cavern, the low-temperature heat storage device and the high-temperature heat storage device through the compression side heat exchange system and the cooler; the expansion unit is connected to the salt cavern, the low-temperature heat storage device and the high-temperature heat storage device through the expansion side heat exchange system; a switching valve is arranged between the compressor unit and the expansion unit. According to the invention, rapid switching between the energy storage mode and the energy release mode of the compressed air energy storage power station is realized, so that the increasingly frequent peak regulation requirement of a power grid is met.

Description

Technical Field

[0001] The present application relates to the field of air energy storage technology, and in particular to a system and method for quickly switching between energy storage and release modes in a large-scale compressed air energy storage power station. Background Art

[0002] Compressed air energy storage is an advanced technology that stores energy through compressed air. It has the advantages of large capacity and long service life. As an efficient and sustainable energy storage method, it has broad application prospects in renewable energy utilization and grid peak regulation.

[0003] Under the situation of rapid development of new energy, due to the volatility and intermittency of renewable energy, higher requirements are put forward for the safe and stable operation level of the power system. The peak-shaving gap of the power grid is increasing day by day, and it has changed from the traditional one peak and one valley to multiple peaks and multiple valleys, which also puts forward higher requirements for the energy storage and release switching time of the energy storage power station. At present, the compressed air energy storage power station needs to stop the compressor for about 30 minutes and then start the expander for about 15 minutes to switch from the energy storage mode to the energy release mode, a total of 45 minutes; from the energy release mode to the energy storage mode, it is also necessary to stop the expander for about 15 minutes and then start the compressor for about 30 minutes, a total of 45 minutes; limited by the conditions such as salt caverns, the start-stop rate of the compressor unit and the start-stop rate of the expander unit, the energy storage and release mode switching time of the compressed air energy storage power station is relatively long, which is difficult to meet the increasingly frequent peak-shaving needs of the power grid. In order to meet the peak-shaving needs of the power grid, it is of great practical significance to study how to further shorten the switching time of the energy storage and release modes of large-scale compressed air energy storage power stations. Summary of the invention

[0004] The purpose of the embodiments of the present application is to provide a system and method for quickly switching the storage and release modes of a large-scale compressed air energy storage power station, which can realize the rapid switching of the storage and release modes of a large-scale compressed air energy storage power station to meet the increasingly frequent peak-shaving needs of the power grid.

[0005] To achieve the above objectives, this application provides the following technical solutions:

[0006] In the first aspect, the present application provides a system for rapidly switching the energy storage and release modes of a large-scale compressed air energy storage power station, including a compressor unit, a compression side heat exchange system, a cooler, an expansion unit, an expansion side heat exchange system, a salt cavern, a low-temperature heat storage device, a high-temperature heat storage device, a switching valve, a high-temperature heat storage circulation pump, a low-temperature heat storage circulation pump, a stop valve, a motor, and a generator;

[0007] The compressor unit adopts four-stage compression, including a first-stage compressor, a second-stage compressor, a third-stage compressor, and a fourth-stage compressor, which are connected to a salt cavern, a low-temperature heat storage device, and a high-temperature heat storage device through a compression side heat exchange system and a cooler. The compressor unit is connected to a motor shaft, and the motor drives the compressor unit to do work;

[0008] The expansion unit adopts three-stage expansion, including a first-stage expander, a second-stage expander, and a third-stage expander, which are connected to the salt cavern, the low-temperature heat storage device, and the high-temperature heat storage device through the expansion side heat exchange system. The expansion unit is connected to the generator shaft, and the expander drives the generator to generate electricity;

[0009] The compression side heat exchange system includes a first-stage compression side heat exchange system, a second-stage compression side heat exchange system, and a third-stage compression side heat exchange system, which are used for heat exchange between the outlet air of the compressor unit and the cooling water of the low-temperature heat storage device;

[0010] The expansion side heat exchange system includes a primary expansion side heat exchange system, a secondary expansion side heat exchange system, and a tertiary expansion side heat exchange system, which are used for heat exchange between the inlet air of the expander and the hot water of the high-temperature heat storage device;

[0011] The cooler includes a primary cooler, a secondary cooler, a tertiary cooler, and a quaternary cooler, which are used to further cool the outlet air of the compressor unit;

[0012] The stop valves include a stop valve from the salt cavern to the expansion unit, a stop valve from the compressor unit to the salt cavern, a stop valve on the expansion side of the high-temperature heat storage device, a stop valve on the expansion side of the low-temperature heat storage device, a stop valve on the compression side of the low-temperature heat storage device, and a stop valve on the compression side of the high-temperature heat storage device;

[0013] A switching valve is arranged between the compressor unit and the expansion unit.

[0014] When the switching system is in the energy storage mode, the compressor unit is connected to the motor shaft, the motor drives the compressor unit to do work, the inlet of the first-stage compressor is connected to the atmosphere, the outlet of the first-stage compressor is connected to the first-stage compression side heat exchange system, the outlet of the first-stage compression side heat exchange system is connected to the first-stage cooler, the outlet of the first-stage cooler is connected to the inlet of the second-stage compressor, the outlet of the second-stage compressor is connected to the second-stage compression side heat exchange system, the outlet of the second-stage compression side heat exchange system is connected to the second-stage cooler, the outlet of the second-stage cooler is connected to the inlet of the third-stage compressor, the outlet of the third-stage compressor is connected to the third-stage compression side heat exchange system, the outlet of the third-stage compression side heat exchange system is connected to the third-stage cooler, the outlet of the third-stage cooler is connected to the inlet of the fourth-stage compressor, the outlet of the fourth-stage compressor is connected to the fourth-stage cooler, and the outlet of the fourth-stage cooler is connected to the salt cavern through the compressor unit to salt cavern stop valve; the outlet of the low-temperature heat storage device is connected to the inlet of the low-temperature heat storage circulation pump through the low-temperature heat storage device compression side stop valve, and the outlet of the low-temperature heat storage circulation pump is connected to the high-temperature heat storage device through the compression side heat exchange system and the high-temperature heat storage device compression side stop valve;

[0015] The switching system is in energy release mode, and air enters the primary expansion side heat exchange system from the salt cavern through the salt cavern to the stop valve of the expansion unit, the outlet of the primary expansion side heat exchange system is connected to the primary expander, the outlet of the primary expander is connected to the secondary expansion side heat exchange system, the outlet of the secondary expansion side heat exchange system is connected to the secondary expander, the outlet of the secondary expander is connected to the tertiary expansion side heat exchange system, the outlet of the tertiary expansion side heat exchange system is connected to the tertiary expander, the outlet of the tertiary expansion side heat exchange system is discharged into the atmosphere, and the expander drives the generator to generate electricity; the outlet of the high-temperature heat storage device is connected to the inlet of the high-temperature heat storage circulation pump through the expansion side stop valve of the high-temperature heat storage device, and the outlet of the high-temperature heat storage circulation pump is connected to the low-temperature heat storage device through the expansion side heat exchange system and the expansion side stop valve of the low-temperature heat storage device.

[0016] In a second aspect, the present application provides a method for rapidly switching the energy storage and release modes of a large-scale compressed air energy storage power station, which uses the system as described above, including rapidly switching the energy storage mode to the energy release mode and rapidly switching the energy release mode to the energy storage mode.

[0017] The rapid switching from energy storage mode to energy release mode includes the following steps:

[0018] (1) The compressor unit operates under load to inflate the salt cavern, and the compressed air energy storage power station is in energy storage mode;

[0019] (2) Open the expansion side stop valve of the high-temperature heat storage device, start the high-temperature heat storage circulation pump, interlock and open the expansion side stop valve of the low-temperature heat storage device, and put the first-stage expansion side heat exchange system, the second-stage expansion side heat exchange system, and the third-stage expansion side heat exchange system into operation;

[0020] (3) Open the switching valve between the compressor unit and the expander unit, and the high-pressure air at the outlet of the fourth-stage compressor directly enters the inlet of the first-stage expander;

[0021] (4) The expansion unit is started up, connected to the grid and loaded;

[0022] (5) When the air flow rate at the outlet of the fourth-stage compressor is substantially equal to the air flow rate at the inlet of the first-stage expander, the stop valve from the compressor unit to the salt cavern is closed, and all the air at the outlet of the fourth-stage compressor enters the first-stage expander. At this time, the salt cavern is neither inflated nor deflated;

[0023] (6) Open the stop valve from the salt cavern to the expansion unit;

[0024] (7) Stop the low-temperature heat storage circulation pump, interlock and close the low-temperature heat storage device compression side stop valve and the high-temperature heat storage device compression side stop valve, stop the compressor unit, and interlock and close the switching valve between the compressor unit and the expansion unit;

[0025] (8) The air inlet of the first-stage expander is switched from the outlet of the fourth-stage compressor to the salt cavern, and the salt cavern begins to release air. The compressed air energy storage power station quickly switches from the energy storage mode to the energy release mode.

[0026] The rapid switching from energy release mode to energy storage mode includes the following steps:

[0027] (1) The expansion unit is running under load, the salt cavern is deflated, and the compressed air energy storage power station is in energy release mode;

[0028] (2) Open the shut-off valve on the compression side of the low-temperature heat storage device, start the low-temperature heat storage circulation pump, interlock and open the shut-off valve on the compression side of the high-temperature heat storage device, and put the first-stage compression side heat exchange system, the first-stage cooler, the second-stage compression side heat exchange system, the second-stage cooler, the third-stage compression side heat exchange system, the third-stage cooler, and the fourth-stage cooler into operation;

[0029] (3) Start the compressor unit;

[0030] (4) Gradually load the compressor unit. When the outlet pressure of the fourth-stage compressor is basically matched with the inlet pressure of the first-stage expander, open the switching valve between the compressor unit and the expander unit, and the high-pressure air at the outlet of the fourth-stage compressor directly enters the inlet of the first-stage expander;

[0031] (5) Continue to load the compressor unit. When the air flow rate at the outlet of the fourth-stage compressor is substantially equal to the air flow rate at the inlet of the first-stage expander, close the stop valve from the salt cavern to the expander unit. All the air at the outlet of the fourth-stage compressor enters the first-stage expander. At this time, the salt cavern is neither inflated nor deflated.

[0032] (6) Open the shut-off valve from the compressor unit to the salt cavern;

[0033] (7) Stop the operation of the high-temperature heat storage circulation pump, interlock and close the stop valve on the expansion side of the high-temperature heat storage device and the stop valve on the expansion side of the low-temperature heat storage device, stop the operation of the expansion unit, and interlock and close the switching valve between the compressor unit and the expansion unit;

[0034] (8) The outlet air of the four-stage compressor switches from entering the first-stage expander to entering the salt cavern, the salt cavern begins to be inflated, and the compressed air energy storage power station quickly switches from the energy release mode to the energy storage mode.

[0035] Compared with the prior art, the beneficial effects of the present invention are as follows: by arranging a switching valve between the compressor unit and the expansion unit, a high-temperature heat storage circulation pump, a low-temperature heat storage circulation pump, a high-temperature heat storage device expansion side stop valve, a low-temperature heat storage device expansion side stop valve, a low-temperature heat storage device compression side stop valve, and a high-temperature heat storage device compression side stop valve, the high-pressure air at the outlet of the four-stage compressor can directly enter the first-stage expander to generate power without passing through the salt cavern, so that the compressed air energy storage power station is not restricted by the salt cavern, the compression side heat exchange system, the expansion side heat exchange system, the start and stop rate of the compressor unit and the start and stop rate of the expansion unit, and the rapid switching of the storage and release modes of the large-scale compressed air energy storage power station is realized, and the problem of the long rapid switching of the storage and release modes of the existing compressed air energy storage power station is solved, so as to meet the increasingly frequent peak-shaving needs of the power grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0037] Figure 1 It is a schematic diagram of the system structure of this application.

[0038] Figure 2 This is the simulation result of this application. Figure 1 .

[0039] Figure 3 This is the simulation result of this application. Figure 2 .

[0040] Figure 1 In: 1-motor, 2-first-stage compressor, 3-second-stage compressor, 4-third-stage compressor, 5-fourth-stage compressor, 6-salt cavern, 7-first-stage expander, 8-second-stage expander, 9-third-stage expander, 10-generator, 11-first-stage cooler, 12-second-stage cooler, 13-third-stage cooler, 14-fourth-stage cooler, 15-stop valve from compressor unit to salt cavern, 16-stop valve from salt cavern to expander unit, 17-first-stage compression side heat exchange system, 18-second-stage compression side heat exchange system system, 19- is a three-stage compression side heat exchange system, 20- is a switching valve, 21- is a first-stage expansion side heat exchange system, 22- is a second-stage expansion side heat exchange system, 23- is a three-stage expansion side heat exchange system, 24- is a low-temperature heat storage circulation pump, 25- is a low-temperature heat storage device compression side stop valve, 26- is a low-temperature heat storage device, 27- is a low-temperature heat storage device expansion side stop valve, 28- is a high-temperature heat storage device compression side stop valve, 29- is a high-temperature heat storage device, 30- is a high-temperature heat storage device expansion side stop valve, and 31- is a high-temperature heat storage circulation pump. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0042] The terms "comprises," "comprising," or any other variation thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0043] The terms "first", "second", etc. are only used to distinguish one entity or operation from another entity or operation, and should not be understood as indicating or implying relative importance, nor should they be understood as requiring or implying any such actual relationship or order between these entities or operations.

[0044] Under the situation of rapid development of new energy, due to the volatility and intermittency of renewable energy, higher requirements are placed on the safe and stable operation level of the power system. The peak-shaving gap of the power grid is increasing, and higher requirements are placed on the peak-shaving capacity of energy storage power stations.

[0045] The present application provides a system and method for quickly switching the energy storage and release modes of a large-scale compressed air energy storage power station. By setting a switching valve between the compressor unit and the expansion unit, a high-temperature heat storage circulation pump, a low-temperature heat storage circulation pump, a high-temperature heat storage device expansion side stop valve, a low-temperature heat storage device expansion side stop valve, a low-temperature heat storage device compression side stop valve, and a high-temperature heat storage device compression side stop valve, the compressed air energy storage power station is not restricted by the salt cavern, the compression side heat exchange system, the expansion side heat exchange system, the compressor unit start and stop rate, and the expansion unit start and stop rate, so that the large-scale compressed air energy storage power station can quickly switch the energy storage and release mode, and solve the problem of long time for the rapid switching of the energy storage and release mode of the existing compressed air energy storage power station, so as to meet the increasingly frequent peak-shaving needs of the power grid.

[0046] like Figure 1 As shown, the present application provides a system for fast switching of storage and release modes of a large-scale compressed air energy storage power station, characterized in that it includes a compressor unit, a compression side heat exchange system, a cooler, an expansion unit, an expansion side heat exchange system, a salt cavern 6, a low-temperature heat storage device 26, a high-temperature heat storage device 29, a switching valve 20, a high-temperature heat storage circulation pump 31, a low-temperature heat storage circulation pump 24, a stop valve, a motor 1, and a generator 10;

[0047] The compressor unit adopts four-stage compression, including a first-stage compressor 2, a second-stage compressor 3, a third-stage compressor 4, and a fourth-stage compressor 5, which are connected to a salt cavern 6, a low-temperature heat storage device 26, and a high-temperature heat storage device 29 through a compression side heat exchange system and a cooler. The compressor unit is connected to the shaft of a motor 1, and the motor 1 drives the compressor unit to do work;

[0048] The expansion unit adopts three-stage expansion, including a first-stage expansion machine 7, a second-stage expansion machine 8, and a third-stage expansion machine 9, which are connected to the salt cavern 6, the low-temperature heat storage device 26, and the high-temperature heat storage device 29 through the expansion side heat exchange system. The expansion unit is connected to the shaft of the generator 10, and the expander drives the generator 10 to generate electricity;

[0049] The compression side heat exchange system includes a first-stage compression side heat exchange system 17, a second-stage compression side heat exchange system 18, and a third-stage compression side heat exchange system 19, which are used for heat exchange between the outlet air of the compressor unit and the cooling water of the low-temperature heat storage device 26;

[0050] The expansion side heat exchange system includes a primary expansion side heat exchange system 21, a secondary expansion side heat exchange system 22, and a tertiary expansion side heat exchange system 23, which are used for heat exchange between the inlet air of the expander and the hot water of the high temperature heat storage device 29;

[0051] The cooler includes a primary cooler 11, a secondary cooler 12, a tertiary cooler 13, and a quaternary cooler 14, which are used to further cool the outlet air of the compressor unit;

[0052] The stop valves include a stop valve 16 from the salt cavern to the expansion unit, a stop valve 15 from the compressor unit to the salt cavern, a stop valve 30 on the expansion side of the high-temperature heat storage device, a stop valve 27 on the expansion side of the low-temperature heat storage device, a stop valve 25 on the compression side of the low-temperature heat storage device, and a stop valve 28 on the compression side of the high-temperature heat storage device;

[0053] A switching valve 20 is provided between the compressor unit and the expansion unit.

[0054] A large-scale compressed air energy storage power station energy storage and release mode fast switching system, including energy storage mode and energy release mode:

[0055] In the energy storage mode, the compressor unit is connected to the shaft of the motor 1, the motor 1 drives the compressor unit to do work, the inlet of the first-stage compressor 2 is connected to the atmosphere, the outlet of the first-stage compressor 2 is connected to the first-stage compression side heat exchange system 17, the outlet of the first-stage compression side heat exchange system 17 is connected to the first-stage cooler 11, the outlet of the first-stage cooler 11 is connected to the inlet of the second-stage compressor 3, the outlet of the second-stage compressor 3 is connected to the second-stage compression side heat exchange system 18, the outlet of the second-stage compression side heat exchange system 18 is connected to the second-stage cooler 12, the outlet of the second-stage cooler 12 is connected to the inlet of the third-stage compressor 4, and the outlet of the third-stage compressor 4 is connected to the third-stage compressor 4. The outlet of the three-stage compression side heat exchange system 19 is connected to the three-stage cooler 13, the outlet of the three-stage cooler 13 is connected to the inlet of the four-stage compressor 5, the outlet of the four-stage compressor 5 is connected to the four-stage cooler 14, and the outlet of the four-stage cooler 14 is connected to the salt cavern 6 through the compressor unit to the salt cavern stop valve 15; the outlet of the low-temperature heat storage device 26 is connected to the inlet of the low-temperature heat storage circulation pump 24 through the low-temperature heat storage device compression side stop valve 25, and the outlet of the low-temperature heat storage circulation pump 24 is connected to the high-temperature heat storage device 29 through the compression side heat exchange system and the high-temperature heat storage device compression side stop valve 28;

[0056] In the energy release mode, air enters the primary expansion side heat exchange system 21 from the salt cavern 6 through the salt cavern to the expansion unit stop valve 16, the outlet of the primary expansion side heat exchange system 21 is connected to the primary expansion machine 7, the outlet of the primary expansion machine 7 is connected to the secondary expansion side heat exchange system 22, the outlet of the secondary expansion side heat exchange system 22 is connected to the secondary expansion machine 8, the outlet of the secondary expansion machine 8 is connected to the tertiary expansion side heat exchange system 23, the outlet of the tertiary expansion side heat exchange system 23 is connected to the tertiary expansion machine 9, the outlet of the tertiary expansion machine 9 is discharged into the atmosphere, and the expander drives the generator 10 to generate electricity; the outlet of the high-temperature heat storage device 29 is connected to the inlet of the high-temperature heat storage circulation pump 31 through the high-temperature heat storage device expansion side stop valve 30, and the outlet of the high-temperature heat storage circulation pump 31 is connected to the low-temperature heat storage device 26 through the expansion side heat exchange system and the low-temperature heat storage device expansion side stop valve 27.

[0057] A method for quickly switching the energy storage and release modes of a large compressed air energy storage power station, using the system as described above, is divided into two cases. The first case is that the energy storage mode is quickly switched to the energy release mode, and the second case is that the energy release mode is quickly switched to the energy storage mode, including the following steps:

[0058] Energy storage mode quickly switches to energy release mode:

[0059] (1) The compressor unit is running at a load of about 250MW, inflating the salt cavern 6, and the compressed air energy storage power station is in energy storage mode;

[0060] (2) Open the expansion-side stop valve 30 of the high-temperature heat storage device, start the high-temperature heat storage circulation pump 31, interlock and open the expansion-side stop valve 27 of the low-temperature heat storage device, and put the first-stage expansion-side heat exchange system 21, the second-stage expansion-side heat exchange system 22, and the third-stage expansion-side heat exchange system 23 into operation;

[0061] (3) Open the switching valve 20 between the compressor unit and the expander unit, and the high-pressure air at the outlet of the fourth-stage compressor 5 directly enters the inlet of the first-stage expander 7;

[0062] (4) The expansion unit is started up, connected to the grid, and carries a load of 170MW;

[0063] (5) When the air flow rate at the outlet of the fourth-stage compressor 5 is substantially equal to the air flow rate at the inlet of the first-stage expander 7, the shut-off valve 15 from the compressor unit to the salt cavern is closed, and all the air at the outlet of the fourth-stage compressor 5 enters the first-stage expander 7. At this time, the salt cavern 6 is neither inflated nor deflated;

[0064] (6) Open the stop valve 16 from the salt cavern 6 to the expansion unit;

[0065] (7) Stop the low-temperature heat storage circulation pump 24, interlock and close the low-temperature heat storage device compression side stop valve 25 and the high-temperature heat storage device compression side stop valve 28, stop the compressor unit, and interlock and close the switching valve 20 between the compressor unit and the expansion unit;

[0066] (8) The inlet air of the first-stage expander 7 is switched from the outlet of the fourth-stage compressor 5 to the salt cavern 6, and the salt cavern 6 begins to release air. The compressed air energy storage power station quickly switches from the energy storage mode to the energy release mode.

[0067] The energy release mode quickly switches to the energy storage mode:

[0068] (1) The expansion unit is running at load, about 170MW, the salt cavern 6 is deflated, and the compressed air energy storage power station is in energy release mode;

[0069] (2) Open the low-temperature heat storage device compression side stop valve 25, start the low-temperature heat storage circulation pump 24, interlock and open the high-temperature heat storage device compression side stop valve 28, and put the first-stage compression side heat exchange system 17, the first-stage cooler 11, the second-stage compression side heat exchange system 18, the second-stage cooler 12, the third-stage compression side heat exchange system 19, the third-stage cooler 13, and the fourth-stage cooler 14 into operation;

[0070] (3) Start the compressor unit;

[0071] (4) Gradually load the compressor unit. When the outlet pressure of the fourth-stage compressor 5 is substantially matched with the inlet pressure of the first-stage expander 7, open the switching valve 20 between the compressor unit and the expander unit, and the high-pressure air at the outlet of the fourth-stage compressor 5 directly enters the inlet of the first-stage expander 7;

[0072] (5) Continue to load the compressor unit to about 250MW. When the air flow rate at the outlet of the fourth-stage compressor 5 is substantially equal to the air flow rate at the inlet of the first-stage expander 7, close the stop valve 16 from the salt cavern to the expander unit. All the air at the outlet of the fourth-stage compressor 5 enters the first-stage expander 7. At this time, the salt cavern 6 is neither inflated nor deflated.

[0073] (6) Open the compressor unit to the salt cave shut-off valve 15;

[0074] (7) Stop the high-temperature heat storage circulation pump 31, interlock and close the high-temperature heat storage device expansion side stop valve 30 and the low-temperature heat storage device expansion side stop valve 27, stop the expansion unit, and interlock and close the switching valve 20 between the compressor unit and the expansion unit;

[0075] (8) The outlet air of the four-stage compressor 5 switches from entering the first-stage expander 7 to entering the salt cavern 6. The salt cavern 6 begins to be inflated, and the compressed air energy storage power station quickly switches from the energy release mode to the energy storage mode.

[0076] A method for quickly switching the energy storage and release modes of a large-scale compressed air energy storage power station is disclosed. By setting a high-temperature heat storage circulation pump 31, a low-temperature heat storage circulation pump 24, a high-temperature heat storage device expansion side stop valve 30, a low-temperature heat storage device expansion side stop valve 27, a low-temperature heat storage device compression side stop valve 25, and a high-temperature heat storage device compression side stop valve 28, the compression side heat exchange system and the expansion side heat exchange system are respectively connected to the low-temperature heat storage device 26 and the high-temperature heat storage device 29 through different interfaces, so that the compression side heat exchange system and the expansion side heat exchange system can operate simultaneously, thereby meeting the requirements of simultaneous operation of the energy storage mode and the energy release mode.

[0077] A method for quickly switching the energy storage and release modes of a large-scale compressed air energy storage power station is disclosed. By setting a switching valve 20 between the compressor unit and the expansion unit, the high-pressure air at the outlet of the four-stage compressor 5 directly enters the first-stage expansion machine 7 to generate power without passing through the salt cavern 6, so that the compressed air energy storage power station is not restricted by the salt cavern 6, the compression side heat exchange system, the expansion side heat exchange system, the start and stop rate of the compressor unit and the start and stop rate of the expansion unit, thereby realizing the rapid switching of the energy storage and release modes of the compressed air energy storage power station.

[0078] like Figure 2 , Figure 3 As shown, a schematic diagram of the charging and discharging power simulation results of a large-scale compressed air energy storage power station in the present application with rapid switching of the storage and release modes is shown. Figure 2 , Figure 3It can be known that in this application, by setting a switching valve between the compressor unit and the expansion unit, a high-temperature heat storage circulation pump, a low-temperature heat storage circulation pump, a high-temperature heat storage device expansion side stop valve, a low-temperature heat storage device expansion side stop valve, a low-temperature heat storage device compression side stop valve, and a high-temperature heat storage device compression side stop valve, the high-pressure air at the outlet of the four-stage compressor can directly enter the first-stage expander to generate power without passing through the salt cavern, so that the compressed air energy storage power station is not restricted by the salt cavern, the compression side heat exchange system, the expansion side heat exchange system, the start and stop rate of the compressor unit and the start and stop rate of the expansion unit, and realizes the rapid switching of the storage and release mode of the large-scale compressed air energy storage power station, and solves the problem of long rapid switching of the storage and release mode of the existing compressed air energy storage power station, so as to meet the increasingly frequent peak-shaving needs of the power grid.

[0079] The above description is only an embodiment of the present application and is not intended to limit the protection scope of the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A large-scale compressed air energy storage power station storage and release mode rapid switching system, characterized in that: It includes a compressor unit, a compression side heat exchange system, a cooler, an expansion unit, an expansion side heat exchange system, a salt cavern, a low temperature heat storage device, a high temperature heat storage device, a switching valve, a high temperature heat storage circulation pump, a low temperature heat storage circulation pump, a stop valve, a motor, and a generator; The compressor unit adopts four-stage compression, including a first-stage compressor, a second-stage compressor, a third-stage compressor, and a fourth-stage compressor, which are connected to a salt cavern, a low-temperature heat storage device, and a high-temperature heat storage device through a compression side heat exchange system and a cooler. The compressor unit is connected to a motor shaft, and the motor drives the compressor unit to do work; The expansion unit adopts three-stage expansion, including a first-stage expander, a second-stage expander, and a third-stage expander, which are connected to the salt cavern, the low-temperature heat storage device, and the high-temperature heat storage device through the expansion side heat exchange system. The expansion unit is connected to the generator shaft, and the expander drives the generator to generate electricity; The compression side heat exchange system includes a first-stage compression side heat exchange system, a second-stage compression side heat exchange system, and a third-stage compression side heat exchange system, which are used for heat exchange between the outlet air of the compressor unit and the cooling water of the low-temperature heat storage device; The expansion side heat exchange system includes a primary expansion side heat exchange system, a secondary expansion side heat exchange system, and a tertiary expansion side heat exchange system, which are used for heat exchange between the inlet air of the expander and the hot water of the high-temperature heat storage device; The cooler includes a primary cooler, a secondary cooler, a tertiary cooler, and a quaternary cooler, which are used to further cool the outlet air of the compressor unit; The stop valves include a stop valve from the salt cavern to the expansion unit, a stop valve from the compressor unit to the salt cavern, a stop valve on the expansion side of the high-temperature heat storage device, a stop valve on the expansion side of the low-temperature heat storage device, a stop valve on the compression side of the low-temperature heat storage device, and a stop valve on the compression side of the high-temperature heat storage device; A switching valve is arranged between the compressor unit and the expansion unit.

2. A large-scale compressed air energy storage power station energy storage and release mode rapid switching system according to claim 1, characterized in that: When the switching system is in the energy storage mode, the compressor unit is connected to the motor shaft, the motor drives the compressor unit to do work, the inlet of the first-stage compressor is connected to the atmosphere, the outlet of the first-stage compressor is connected to the first-stage compression side heat exchange system, the outlet of the first-stage compression side heat exchange system is connected to the first-stage cooler, the outlet of the first-stage cooler is connected to the inlet of the second-stage compressor, the outlet of the second-stage compressor is connected to the second-stage compression side heat exchange system, the outlet of the second-stage compression side heat exchange system is connected to the second-stage cooler, the outlet of the second-stage cooler is connected to the inlet of the third-stage compressor, the outlet of the third-stage compressor is connected to the third-stage compression side heat exchange system, the outlet of the third-stage compression side heat exchange system is connected to the third-stage cooler, the outlet of the third-stage cooler is connected to the inlet of the fourth-stage compressor, the outlet of the fourth-stage compressor is connected to the fourth-stage cooler, and the outlet of the fourth-stage cooler is connected to the salt cavern through the compressor unit to salt cavern stop valve; the outlet of the low-temperature heat storage device is connected to the inlet of the low-temperature heat storage circulation pump through the compression side stop valve of the low-temperature heat storage device, and the outlet of the low-temperature heat storage circulation pump is connected to the high-temperature heat storage device through the compression side heat exchange system and the compression side stop valve of the high-temperature heat storage device.

3. A large-scale compressed air energy storage power station energy storage and release mode rapid switching system according to claim 1, characterized in that: The switching system is in energy release mode, and air enters the primary expansion side heat exchange system from the salt cavern through the salt cavern to the stop valve of the expansion unit, the outlet of the primary expansion side heat exchange system is connected to the primary expander, the outlet of the primary expander is connected to the secondary expansion side heat exchange system, the outlet of the secondary expansion side heat exchange system is connected to the secondary expander, the outlet of the secondary expander is connected to the tertiary expansion side heat exchange system, the outlet of the tertiary expansion side heat exchange system is connected to the tertiary expander, the outlet of the tertiary expansion side heat exchange system is discharged into the atmosphere, and the expander drives the generator to generate electricity; the outlet of the high-temperature heat storage device is connected to the inlet of the high-temperature heat storage circulation pump through the expansion side stop valve of the high-temperature heat storage device, and the outlet of the high-temperature heat storage circulation pump is connected to the low-temperature heat storage device through the expansion side heat exchange system and the expansion side stop valve of the low-temperature heat storage device.

4. A method for rapidly switching the energy storage and release modes of a large compressed air energy storage power station, using the system as claimed in claim 1, characterized in that: Including fast switching from energy storage mode to energy release mode and fast switching from energy release mode to energy storage mode, The rapid switching from energy storage mode to energy release mode includes the following steps: (1) The compressor unit operates under load to inflate the salt cavern, and the compressed air energy storage power station is in energy storage mode; (2) Open the expansion side stop valve of the high-temperature heat storage device, start the high-temperature heat storage circulation pump, interlock and open the expansion side stop valve of the low-temperature heat storage device, and put the first-stage expansion side heat exchange system, the second-stage expansion side heat exchange system, and the third-stage expansion side heat exchange system into operation; (3) Open the switching valve between the compressor unit and the expander unit, and the high-pressure air at the outlet of the fourth-stage compressor directly enters the inlet of the first-stage expander; (4) The expansion unit is started up, connected to the grid and loaded; (5) When the air flow rate at the outlet of the fourth-stage compressor is substantially equal to the air flow rate at the inlet of the first-stage expander, the stop valve from the compressor unit to the salt cavern is closed, and all the air at the outlet of the fourth-stage compressor enters the first-stage expander. At this time, the salt cavern is neither inflated nor deflated; (6) Open the stop valve from the salt cavern to the expansion unit; (7) Stop the low-temperature heat storage circulation pump, interlock and close the low-temperature heat storage device compression side stop valve and the high-temperature heat storage device compression side stop valve, stop the compressor unit, and interlock and close the switching valve between the compressor unit and the expansion unit; (8) The air inlet of the first-stage expander is switched from the outlet of the fourth-stage compressor to the salt cavern, and the salt cavern begins to release air. The compressed air energy storage power station quickly switches from the energy storage mode to the energy release mode.

5. A method for rapidly switching the energy storage and release modes of a large-scale compressed air energy storage power station according to claim 4, characterized in that: The rapid switching from energy release mode to energy storage mode includes the following steps: (1) The expansion unit is running under load, the salt cavern is deflated, and the compressed air energy storage power station is in energy release mode; (2) Open the shut-off valve on the compression side of the low-temperature heat storage device, start the low-temperature heat storage circulation pump, interlock and open the shut-off valve on the compression side of the high-temperature heat storage device, and put the first-stage compression side heat exchange system, the first-stage cooler, the second-stage compression side heat exchange system, the second-stage cooler, the third-stage compression side heat exchange system, the third-stage cooler, and the fourth-stage cooler into operation; (3) Start the compressor unit; (4) Gradually load the compressor unit. When the outlet pressure of the fourth-stage compressor is basically matched with the inlet pressure of the first-stage expander, open the switching valve between the compressor unit and the expander unit, and the high-pressure air at the outlet of the fourth-stage compressor directly enters the inlet of the first-stage expander; (5) Continue to load the compressor unit. When the air flow rate at the outlet of the fourth-stage compressor is substantially equal to the air flow rate at the inlet of the first-stage expander, close the stop valve from the salt cavern to the expander unit. All the air at the outlet of the fourth-stage compressor enters the first-stage expander. At this time, the salt cavern is neither inflated nor deflated. (6) Open the shut-off valve from the compressor unit to the salt cavern; (7) Stop the operation of the high-temperature heat storage circulation pump, interlock and close the stop valve on the expansion side of the high-temperature heat storage device and the stop valve on the expansion side of the low-temperature heat storage device, stop the operation of the expansion unit, and interlock and close the switching valve between the compressor unit and the expansion unit; (8) The outlet air of the four-stage compressor switches from entering the first-stage expander to entering the salt cavern, the salt cavern begins to be inflated, and the compressed air energy storage power station quickly switches from the energy release mode to the energy storage mode.

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