System for slowing down corrosion of ground facilities of voltage storage power station and operation method of system

Abstract

The invention discloses a system for relieving corrosion of ground facilities of a compressed air energy storage power station, and relates to the technical field of heat storage and exchange systems of compressed air energy storage power stations. The system comprises a compressed air system, an expansion power generation system, a heat storage and exchange system and a gas storage system, and further comprises a staged cooling / preheating system, and the staged cooling / preheating system comprises a tail-section compressor outlet heat exchanger, a first-stage expansion inlet heat exchanger, a gas storage inlet and outlet heat exchanger and a gas storage inlet and outlet separator. The corrosion problem of the compressed air pipeline and the heat exchanger equipment can be effectively relieved, so that the manufacturing cost of the compressed air main pipe and the heat exchanger equipment is reduced, and the economical efficiency of a power station is improved. The invention further relates to an operation method of the system for relieving corrosion of the ground facilities of the pressure storage power station.

Description

Technical Field

[0001] The present invention relates to the technical field of heat storage and exchange systems of compressed air energy storage power stations, and more specifically, to a system for mitigating corrosion of ground facilities of compressed air energy storage power stations. The present invention also relates to an operation method of the system for mitigating corrosion of ground facilities of compressed air energy storage power stations. Background Art

[0002] Compressed air energy storage system is currently recognized as a large-capacity, ultra-long-duration energy storage technology comparable to pumped storage. It can provide auxiliary services such as peak regulation, frequency regulation, phase regulation, black start, and rotational inertia for the power grid, and has attracted widespread attention from scholars at home and abroad. At present, many large-capacity compressed air energy storage projects have been completed or are under construction in China.

[0003] The compressed air energy storage system mainly includes a compressed air system, an expansion power generation system, a heat storage and exchange system and a gas storage system; wherein the compressed air system mainly includes a multi-stage compressor unit, which is composed of a multi-stage compressor driven by an independent motor in series or a multi-stage compressor driven by a single motor; the expansion power generation system mainly includes an expander and a generator, wherein the expander is composed of at least two or more expanders, and the generator generally adopts an air-cooled generator; the heat storage and exchange system mainly includes a heat storage system and a heat exchange system, wherein the heat storage system can be divided into heat transfer oil heat storage, molten salt heat storage, water heat storage, solid heat storage or multiple heat storage medium cascade heat storage according to different heat storage media, and the heat exchange system mainly includes a compression side heat exchange system and an expansion side heat exchange system, or a compression side and expansion side common heat exchange system, and the main equipment includes a heat exchanger, a cooler and a separator; the gas storage system can be divided into salt cavern gas storage, artificial chamber gas storage, mine cave gas storage, pipeline steel gas storage and pressure vessel gas storage according to the type of gas storage.

[0004] Compressed air energy storage power stations usually operate in two modes: compression energy storage and expansion energy release. In the compression energy storage mode, the compressed air system is started during the off-peak period of power grid electricity or when new energy is used to abandon electricity. The ambient air is pressurized by each compressor stage by stage and then heated and pressurized. The high-temperature and high-pressure air at the compressor outlet is cooled by the compression side heat exchange system (or the common heat exchange system of the compression side and the expansion side) and then enters the inlet of the next compressor or enters the gas storage reservoir for storage. The low-temperature heat storage medium from the low-temperature storage tank absorbs the heat of the high-temperature and high-pressure air in the heat exchanger and heats up before entering the high-temperature storage tank for storage, thereby completing the storage of electricity. Expansion energy release mode: During the peak period of power grid electricity consumption, the expansion power generation system is started. The low-temperature and high-pressure air from the gas storage reservoir is heated and heated by the heat storage medium in the expansion side heat exchange system (or the common heat exchange system of the compression side and the expansion side) through the high-temperature storage tank and then enters the expanders at each stage to expand and do work, converting the pressure potential energy of the compressed air and the thermal energy of the heat storage medium into the rotational kinetic energy of the expander, and finally into electrical energy, completing the release of electrical energy.

[0005] At present, the compressed air energy storage power stations that have been built or are under construction are connected between the gas storage and the compressed air system or expansion power generation system through the compressed air main pipe. Due to the location of the gas storage and the safety and reliability of the ground facilities of the power station, a distance is usually reserved between the ground facilities and the gas storage, resulting in a longer length of this section of the compressed air main pipe; for large-capacity compressed air power stations, this section of the main pipe is generally larger in diameter and is a high-pressure pipe with thicker walls due to the flow rate limit. During the compressed energy storage stage of the power station, the air at the outlet of the last compressor is cooled to below the saturation temperature before entering the gas storage for storage. Although the condensed water in the air is separated by the separator after cooling, it is inevitable that there will be cooling and precipitation of condensed water in the compressed air main pipe due to the long compressed air main pipe process between the outlet of the last compressor and the inlet of the gas storage. The high-pressure oxygen environment plus condensed water will inevitably bring serious high-pressure oxygen corrosion risks to the compressed air main pipe between the outlet of the last compressor and the inlet of the gas storage. During the expansion and energy release stage of the power station, the gas storage comes from low temperature and high temperature. Saturated or nearly saturated moist air will also cool down and condense in the compressed air main pipe, which will bring serious high-pressure oxygen corrosion risks to the compressed air main pipe between the gas storage outlet and the expander inlet heat exchanger; in addition, when a salt cavern gas storage is used, the brine remaining in the salt cavern and the multi-layer rock salt structure of the gas storage will further deteriorate the quality of the compressed air from the gas storage. The compressed air carrying salt-containing condensed water or particulate matter will cause devastating damage to the compressed air main pipe and even the first-stage expansion inlet heat exchanger of the expander, which will cause great harm to the safe and stable operation of the power station.

[0006] In order to avoid the above problems, the conventional practice is to increase the corrosion margin of the pipeline, thicken the wall of the compressed air main pipe, or line the compressed air main pipe with anti-corrosion materials such as stainless steel and organic matter; for the first-stage expansion inlet heat exchanger equipment, the parts in contact with the compressed air in the heat exchanger are generally made of corrosion-resistant stainless steel. Although the above practices can resist corrosion problems to a certain extent, they will inevitably lead to an increase in the cost of the compressed air main pipe and heat exchanger equipment, which is contrary to the current demand for further cost reduction of compressed air energy storage power stations, and restricts the healthy development of compressed air energy storage power stations.

[0007] Therefore, it is necessary to develop a system and an operating method for reducing the corrosion of the compressed air main pipe and the expander inlet heat exchanger equipment by the low-temperature, high-pressure, saturated wet air or salt-containing condensate from the final compressor or gas storage at a relatively low cost, and to reduce the total heat exchange area of ​​the final compressor outlet heat exchanger and the first-stage expansion inlet heat exchanger, thereby greatly reducing the cost of the compressed air main pipe and the heat exchanger equipment, and thus reducing the total investment of the power station, while effectively ensuring the safe operation of the compressed air main pipe and the heat exchanger equipment. Summary of the invention

[0008] The first purpose of the present invention is to overcome the shortcomings of the above-mentioned background technology and provide a system for mitigating corrosion of ground facilities of a pressure storage power station.

[0009] The second object of the present invention is to provide an operating method of the system for mitigating corrosion of ground facilities of a pressure storage power station.

[0010] In order to achieve the above-mentioned first purpose, the technical solution of the present invention is: a system for mitigating corrosion of ground facilities of a compressed storage power station, comprising a compressed air system, an expansion power generation system, a heat storage and exchange system and a gas storage system, wherein the compressed air system comprises n-stage compressors connected in series, n≥2; the expansion power generation system comprises m-stage expanders connected in series, m≥2; the heat storage and exchange system comprises a heat storage system and a heat exchange system; the heat storage system comprises at least one high-temperature storage tank and at least one low-temperature storage tank, and the high-temperature storage tank and the low-temperature storage tank are both connected to the heat exchange system; the heat exchange system is arranged between n compressors connected in series and between m expanders connected in series; the gas storage system comprises a gas storage, the n-stage compressor is connected to the third compressed air main pipe through the first compressed air main pipe, the first-stage expander is connected to the third compressed air main pipe through the second compressed air main pipe, and the third compressed air main pipe is connected to the gas storage;

[0011] It is characterized in that: it also includes a graded cooling / preheating system, which includes a heat exchanger at the outlet of the last compressor, a heat exchanger at the inlet of the first expansion, a heat exchanger at the inlet and outlet of the gas storage, and a separator at the inlet and outlet of the gas storage;

[0012] The final compressor outlet heat exchanger is connected to the nth compressor outlet; the first-stage expansion inlet heat exchanger is connected to the first-stage expander inlet;

[0013] The gas storage is connected to the first compressed air main pipe and the second compressed air main pipe in sequence through the gas storage inlet and outlet separators and the gas storage inlet and outlet heat exchangers on the third compressed air main pipe;

[0014] When m=n-1 and the cooling medium of the final compressor outlet heat exchanger is arranged in parallel with the gas storage inlet and outlet heat exchanger, the cooling tower is connected to the final compressor outlet heat exchanger and the gas storage inlet and outlet heat exchanger; the gas storage inlet and outlet heat exchanger is connected to the first-stage expansion inlet heat exchanger and the low-temperature storage tank;

[0015] When m=n, the gas storage inlet and outlet heat exchangers are connected to the final compressor outlet heat exchanger, the primary expansion inlet heat exchanger and the low-temperature storage tank.

[0016] In the above technical scheme, when m=n-1, the cooling tower medium outlet is connected to the gas storage inlet and outlet heat exchangers through a cooling water inlet shut-off valve, and the cooling tower medium inlet is connected to the gas storage inlet and outlet heat exchangers through a cooling return water shut-off valve; the first-stage expansion inlet heat exchanger is connected to the gas storage inlet and outlet heat exchangers through a preheating water inlet shut-off valve; the gas storage inlet and outlet heat exchangers are connected to the low-temperature storage tank through a preheating return water shut-off valve.

[0017] In the above technical scheme, when m=n-1 and the cooling medium of the last-stage compressor outlet heat exchanger is arranged in series with the cooling medium of the gas storage inlet and outlet heat exchanger, the cooling tower medium outlet is connected to the gas storage inlet and outlet heat exchanger through a cooling water inlet shut-off valve, the gas storage inlet and outlet heat exchanger is connected to the medium inlet of the last-stage compressor outlet heat exchanger through a cooling return water shut-off valve, and the medium outlet of the last-stage compressor outlet heat exchanger is connected to the medium inlet of the cooling tower.

[0018] In the above technical solution, the inlet and outlet heat exchangers of the gas storage reservoir are connected to the outlet heat exchanger of the last stage compressor through a cooling return water shut-off valve, and the first-stage expansion inlet heat exchanger is connected to the inlet and outlet heat exchangers of the gas storage reservoir through a preheating water inlet shut-off valve; the inlet and outlet heat exchangers of the gas storage reservoir are connected to the low-temperature storage tank through a cooling water inlet / preheating return water shut-off valve.

[0019] In order to achieve the above-mentioned first purpose, the technical solution of the present invention is: a system for mitigating corrosion of ground facilities of a compressed storage power station, comprising a compressed air system, an expansion power generation system, a heat storage and exchange system and a gas storage system, wherein the compressed air system comprises n-stage compressors connected in series, n≥2; the expansion power generation system comprises m-stage expanders connected in series, m≥2; the heat storage and exchange system comprises a heat storage system and a heat exchange system; the heat storage system comprises at least one high-temperature storage tank and at least one low-temperature storage tank, and the high-temperature storage tank and the low-temperature storage tank are both connected to the heat exchange system; the heat exchange system is arranged between n compressors connected in series and between m expanders connected in series; the gas storage system comprises a gas storage, the n-stage compressor is connected to the third compressed air main pipe through the first compressed air main pipe, the first-stage expander is connected to the third compressed air main pipe through the second compressed air main pipe, and the third compressed air main pipe is connected to the gas storage;

[0020] It is characterized in that: it also includes a staged cooling / preheating system, which includes a final compressor outlet heat exchanger, a primary expansion inlet heat exchanger, a gas storage inlet and outlet heat exchanger, a gas storage inlet and outlet separator and an independent heat storage system;

[0021] The final compressor outlet heat exchanger is connected to the nth compressor outlet; the first-stage expansion inlet heat exchanger is connected to the first-stage expander inlet;

[0022] The gas storage is connected to the first compressed air main pipe and the second compressed air main pipe in sequence through the gas storage inlet and outlet separators and the gas storage inlet and outlet heat exchangers on the third compressed air main pipe;

[0023] The independent heat storage system includes an independent low-heat storage tank and an independent high-heat storage tank, and the independent low-heat storage tank and the independent high-heat storage tank are both connected to the inlet and outlet heat exchangers of the gas storage reservoir;

[0024] The high-temperature storage tank and the low-temperature storage tank are both connected to the final compressor outlet heat exchanger and the first-stage expansion inlet heat exchanger.

[0025] In the above technical solution, the independent low-heat storage tank is connected to the inlet and outlet heat exchangers of the gas storage reservoir through a low-temperature circulation pump and a low-temperature circulation shut-off valve, and the independent high-heat storage tank is connected to the inlet and outlet heat exchangers of the gas storage reservoir through a high-temperature circulation pump and a high-temperature circulation shut-off valve.

[0026] In the above technical solution, the gas storage reservoir is connected to the gas storage reservoir inlet and outlet separators through the gas storage reservoir shut-off valve; the final compressor outlet heat exchanger is connected to the first compressed air main pipe through the compression side shut-off valve; the second compressed air main pipe is connected to the first-stage expansion inlet heat exchanger through the expansion side shut-off valve.

[0027] In the above technical solution, the gas storage inlet and outlet heat exchangers and the gas storage inlet and outlet separators are arranged close to the gas storage.

[0028] In order to achieve the above second purpose, the technical solution of the present invention is: an operation method of a system for mitigating corrosion of ground facilities of a pressure storage power station, characterized in that it includes a compression energy storage stage and an expansion power generation stage;

[0029] The compression energy storage stage comprises the following steps:

[0030] Gas side: close the expansion side shut-off valve, open the compression side shut-off valve and the gas storage shut-off valve; the high-temperature and high-pressure air at the outlet of the nth stage compressor is cooled to above the saturation temperature through the heat exchanger at the outlet of the last stage compressor, and then flows into the gas storage inlet and outlet heat exchangers through the first compressed air main pipe, continues to cool in the gas storage inlet and outlet heat exchangers, and then enters the gas storage through the third compressed air main pipe after liquid water is separated by the gas storage inlet and outlet separators;

[0031] Water side: when m=n-1, close the preheating return water shut-off valve and the preheating inlet water shut-off valve, and open the cooling inlet water shut-off valve and the cooling return water shut-off valve; the low-temperature cooling water from the cooling tower exchanges heat with the low-temperature air in the heat exchangers at the inlet and outlet of the gas storage reservoir through the cooling inlet pipeline, and after the temperature is increased, the cooling water returns to the cooling tower through the cooling return water pipeline for cooling and cooling, thus realizing the recycling of cooling water;

[0032] When m=n, close the preheating water inlet shut-off valve, open the cooling water inlet / preheating water return shut-off valve and the cooling water return shut-off valve; the low-temperature cooling water from the low-temperature storage tank exchanges heat with the low-temperature air in the heat exchanger at the inlet and outlet of the gas storage reservoir through the cooling water inlet / preheating water return pipeline, and the cooling water after heating returns to the heat exchanger at the outlet of the last compressor through the cooling water return pipeline for cooling, thereby realizing the recycling of cooling water;

[0033] The expansion power generation stage comprises the following steps:

[0034] Gas side: close the shut-off valve on the compression side, open the shut-off valve on the expansion side and the shut-off valve on the gas storage reservoir; the saturated wet air or nearly saturated wet air or wet air carrying impurities from the gas storage reservoir enters the inlet and outlet heat exchanger of the gas storage reservoir after the droplets or solid particles are separated by the inlet and outlet separators of the gas storage reservoir, and is heated to above the saturation temperature by the heat storage medium in the inlet and outlet heat exchanger of the gas storage reservoir, and then enters the first-stage expander through the second compressed air main pipe, and is further heated to the rated temperature by the heat storage medium before entering the expander to generate power;

[0035] Water side: when m=n-1, close the cooling water inlet shut-off valve and the cooling return water shut-off valve, and open the preheating return water shut-off valve and the preheating water inlet shut-off valve; after the high-temperature heat storage medium from the high-temperature storage tank is cooled in the first-stage expansion inlet heat exchanger, it enters the gas storage inlet and outlet heat exchangers through the preheating water inlet pipeline, and the low-temperature heat storage medium after further cooling returns to the low-temperature storage tank through the preheating return water pipeline for storage, thereby realizing the recycling of the heat storage medium.

[0036] When m=n, close the cooling return water shut-off valve, and open the preheating water inlet shut-off valve and the cooling water inlet / preheating return water shut-off valve; after the high-temperature heat storage medium from the high-temperature storage tank is cooled in the first-stage expansion inlet heat exchanger, it enters the gas storage reservoir inlet and outlet heat exchangers through the preheating water inlet pipeline, and the low-temperature heat storage medium after further cooling returns to the low-temperature storage tank for storage through the cooling water inlet / preheating return water pipeline, thereby realizing the recycling of the heat storage medium.

[0037] Compared with the prior art, the present invention has the following advantages:

[0038] 1) Compared with conventional compressed air energy storage systems, the compressed air main pipes from the final compressor outlet heat exchanger 610 to the gas storage inlet and outlet heat exchangers 630, from the gas storage inlet and outlet heat exchangers 630 to the first-stage expansion inlet heat exchanger 620, and the compressed air in the final compressor outlet heat exchanger 610 and the first-stage expansion inlet heat exchanger 620 are always maintained above the saturation temperature, and the humid air will not condense and precipitate water, which can effectively alleviate the corrosion problem of compressed air pipelines and heat exchanger equipment, thereby reducing the corrosion margin of the compressed air main pipe during design and selection, or avoiding the use of stainless steel lining or organic anti-corrosion measures, and the parts in the heat exchanger that come into contact with the compressed air can use low-grade steel, avoiding the use of expensive stainless steel, thereby reducing the cost of the compressed air main pipe and heat exchanger equipment in this section and improving the economy of the power station.

[0039] 2) Compared with conventional compressed air energy storage systems, the present invention divides the final compressor outlet heat exchanger 610 and the first-stage expansion inlet heat exchanger 620 into a graded cooling / preheating system design, wherein the gas storage inlet and outlet heat exchanger 630 is used as a low-temperature section and is arranged near the wellhead of the gas storage 410, and is shared by the compression energy storage stage and the expansion power generation stage. Therefore, under the premise of achieving the same cooling / heating function, the overall heat exchange area is smaller than the heat exchanger area of ​​the conventional compressed storage solution, and only the gas storage inlet and outlet heat exchanger 630 adopts an anti-corrosion design (the heat exchange volume accounts for a small proportion of the total heat exchange volume), and the cost is greatly reduced; in addition, the gas storage inlet and outlet heat exchanger 630 is arranged close to the wellhead of the gas storage 410, and the compressed air pipeline between the gas storage 410 wellhead is short, and only this section of the pipeline adopts an anti-corrosion design, so the investment in this section of the compressed air main pipe and heat exchanger equipment can be effectively reduced, further improving the economy of the power station.

[0040] 3) Compared with conventional compressed air energy storage systems, the present invention only has a certain corrosion risk in the compressed air pipeline between the inlet and outlet of the gas storage reservoir 410 and the inlet and outlet heat exchanger 630 of the gas storage reservoir. The risk points are relatively few and concentrated, which can effectively improve the safety and reliability of the power station. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is a schematic diagram of the structure when the cooling medium of the last compressor outlet heat exchanger and the gas storage inlet and outlet heat exchangers are arranged in parallel in Example 1 of the present invention.

[0042] Figure 2 This is a structural schematic diagram of the cooling medium when the heat exchanger at the outlet of the last compressor and the heat exchangers at the inlet and outlet of the gas storage reservoir are arranged in series in Example 1 of the present invention.

[0043] Figure 3 This is a schematic diagram of the structure of Example 2 of the present invention.

[0044] Figure 4 This is a schematic diagram of the structure of Example 3 of the present invention.

[0045] Figure 5 It is a schematic diagram of the structure when m=n-1 in the prior art.

[0046] Figure 6 It is a schematic diagram of the structure when m=n in the prior art.

[0047] Among them, 100-compressed air system, 110-compressor, 111-filter, 200-expansion power generation system, 210-expander, 300-heat storage and exchange system, 310-heat storage system, 311-high temperature storage tank, 312-low temperature storage tank, 320-heat exchange system, 321-compression side heat exchange system, 3211-compression side heat exchanger, 3212-compression side separator, 322-expansion side heat exchange system, 3221-expansion side heat exchanger, 400-gas storage system, 410-gas storage, 420-gas storage shut-off valve, 510-first compressed air main pipe, 520-second compressed air main pipe, 530-third compressed air main pipe, 600-stage cooling / preheating system, 610-last compressor outlet heat exchanger, 611-compression side shut-off valve, 62 0-first-stage expansion inlet heat exchanger, 621-expansion side shut-off valve, 630-gas storage inlet and outlet heat exchanger, 631-cooling water inlet shut-off valve, 6311-cooling water inlet pipeline, 632-cooling return water shut-off valve, 6321-cooling return water pipeline, 633-preheating water inlet shut-off valve, 6331-preheating water inlet pipeline, 634-preheating return water shut-off valve, 6341-preheating return water pipeline, 635-cooling water inlet / preheating return water shut-off valve, 6351-cooling water inlet / preheating return water pipeline, 640-gas storage inlet and outlet separator, 660-independent heat storage system, 661-independent low-heat storage tank, 662-independent high-heat storage tank, 663-low-temperature circulation pump, 664-high-temperature circulation pump, 665-low-temperature circulation shut-off valve, 666-high-temperature circulation shut-off valve, 700-cooling tower. DETAILED DESCRIPTION

[0048] The following detailed description of the implementation of the present invention is made in conjunction with the accompanying drawings, but they do not constitute a limitation of the present invention and are only given as examples. At the same time, the advantages of the present invention will become clearer and easier to understand through the description.

[0049] Conventional storage solutions such as Figure 5 and Figure 6As shown, it includes a compressed air system 100, an expansion power generation system 200, a heat storage and exchange system 300 and a gas storage system 400, wherein the compressed air system 100 includes n-stage compressors 110 connected in series, where n≥2; the expansion power generation system 200 includes m-stage expanders 210 connected in series, where m≥2; the heat storage and exchange system 300 includes a heat storage system 310 and a heat exchange system 320; the heat storage system 310 includes at least one high-temperature storage tank 311 and at least one low-temperature storage tank 312, wherein the high-temperature storage tank 311 and the low-temperature storage tank 312 are connected in series. The storage tanks 312 are all connected to the heat exchange system 320; the heat exchange system 320 is arranged between n compressors 110 connected in series and between m expanders 210 connected in series; the gas storage system 400 includes a gas storage 410, the nth stage compressor 110 is connected to the third compressed air main pipe 530 through the first compressed air main pipe 510, the first stage expander 210 is connected to the third compressed air main pipe 530 through the second compressed air main pipe 520, and the third compressed air main pipe 530 is connected to the gas storage 410.

[0050] Example 1

[0051] like Figure 1 and Figure 2 As shown, this embodiment further includes a staged cooling / preheating system 600 on the basis of a conventional pressure storage solution, and the staged cooling / preheating system 600 includes a final compressor outlet heat exchanger 610, a primary expansion inlet heat exchanger 620, a gas storage inlet and outlet heat exchanger 630, and a gas storage inlet and outlet separator 640; the first stage compressor 110 is connected to the ambient atmosphere through a filter 111;

[0052] The final compressor outlet heat exchanger 610 is connected to the outlet of the nth compressor 110; the first expansion inlet heat exchanger 620 is connected to the inlet of the first expansion machine 210;

[0053] The gas storage 410 is connected to the first compressed air main pipe 510 and the second compressed air main pipe 520 in sequence through the gas storage inlet and outlet separator 640 and the gas storage inlet and outlet heat exchanger 630 on the third compressed air main pipe 530;

[0054] like Figure 1 As shown, when m=n-1 and the cooling medium of the last compressor outlet heat exchanger 610 and the gas storage inlet and outlet heat exchanger 630 is arranged in parallel, the cooling tower 700 is connected to the last compressor outlet heat exchanger 610 and the gas storage inlet and outlet heat exchanger 630; the gas storage inlet and outlet heat exchanger 630 is connected to the first-stage expansion inlet heat exchanger 620 and the low-temperature storage tank 312; the cooling tower 700 is a cooling tower system configured in the original pressure storage power station;

[0055] like Figure 2As shown, when m=n-1 and the cooling medium of the last-stage compressor outlet heat exchanger 610 is arranged in series with the gas storage inlet and outlet heat exchanger 630, the medium outlet of the cooling tower 700 is connected to the gas storage inlet and outlet heat exchanger 630 through a cooling water inlet shut-off valve 631, and the gas storage inlet and outlet heat exchanger 630 is connected to the medium inlet of the last-stage compressor outlet heat exchanger 610 through a cooling return water shut-off valve 632, and the medium outlet of the last-stage compressor outlet heat exchanger 610 is connected to the medium inlet of the cooling tower 700.

[0056] The medium outlet of the cooling tower 700 is connected to the gas storage inlet and outlet heat exchanger 630 through a cooling water inlet shut-off valve 631, and the medium inlet of the cooling tower 700 is connected to the gas storage inlet and outlet heat exchanger 630 through a cooling return water shut-off valve 632; the first-stage expansion inlet heat exchanger 620 is connected to the gas storage inlet and outlet heat exchanger 630 through a preheating water inlet shut-off valve 633; ​​the gas storage inlet and outlet heat exchanger 630 is connected to the low-temperature storage tank 312 through a preheating return water shut-off valve 634.

[0057] The heat exchange system 320 includes a compression side heat exchange system 321 and an expansion side heat exchange system 322 . The compression side heat exchange system 321 includes a compression side heat exchanger 3211 and a compression side separator 3212 . The expansion side heat exchange system 322 includes an expansion side heat exchanger 3221 .

[0058] The heat exchange system 320 is a common heat exchange system for the compression side and the expansion side. The common heat exchange system includes a heat exchanger and a separator, wherein the separator is only used on the compression side, and the heat exchanger is shared by the compression side and the expansion side.

[0059] The gas storage reservoir 410 is connected to the gas storage inlet and outlet separators 640 through the gas storage shut-off valve 420; the final compressor outlet heat exchanger 610 is connected to the first compressed air main pipe 510 through the compression side shut-off valve 611; the second compressed air main pipe 520 is connected to the first-stage expansion inlet heat exchanger 620 through the expansion side shut-off valve 621.

[0060] The gas storage inlet and outlet heat exchanger 630 and the gas storage inlet and outlet separator 640 are arranged adjacent to the gas storage 410 .

[0061] Under normal operating conditions, an operating method of a system for mitigating corrosion of ground facilities of a compressed energy storage power station includes a compression energy storage stage and an expansion power generation stage;

[0062] The compression energy storage stage comprises the following steps:

[0063] Gas side: close the expansion side shut-off valve 621, open the compression side shut-off valve 611 and the gas storage shut-off valve 420; the high-temperature and high-pressure air at the outlet of the nth stage compressor 110 is cooled to above the saturation temperature (saturation temperature + 5°C) through the heat exchanger 610 at the outlet of the last stage compressor, and then flows into the gas storage inlet and outlet heat exchanger 630 through the first compressed air main pipe 510, and continues to be cooled to about 40°C in the gas storage inlet and outlet heat exchanger 630, and then enters the gas storage 410 for storage after liquid water is separated by the gas storage inlet and outlet separator 640;

[0064] Water side: when m=n-1, close the preheating return water shutoff valve 634 and the preheating inlet water shutoff valve 633, and open the cooling inlet water shutoff valve 631 and the cooling return water shutoff valve 632; the low-temperature cooling water from the cooling tower 700 exchanges heat with the low-temperature air in the gas storage inlet and outlet heat exchangers 630 through the cooling inlet water pipeline 6311, and the cooling water after heating returns to the cooling tower 700 through the cooling return water pipeline 6321 for cooling, thereby realizing the recycling of cooling water;

[0065] The expansion power generation stage comprises the following steps:

[0066] Gas side: close the compression side shut-off valve 611, open the expansion side shut-off valve 621 and the gas storage shut-off valve 420; the saturated wet air or nearly saturated wet air or wet air carrying impurities from the gas storage 410 enters the gas storage inlet and outlet heat exchanger 630 after the liquid droplets or solid particles are separated by the gas storage inlet and outlet separator 640, and is heated to above the saturation temperature (saturation temperature + 10°C) by the heat storage medium in the gas storage inlet and outlet heat exchanger 630, and then enters the first-stage expander 210 through the second compressed air main pipe 520, and is further heated to the rated temperature by the heat storage medium before entering the expander 210 to generate power;

[0067] Water side: when m=n-1, close the cooling water inlet shut-off valve 631 and the cooling water return shut-off valve 632, and open the preheating return water shut-off valve 634 and the preheating water inlet shut-off valve 633; ​​the high-temperature heat storage medium from the high-temperature storage tank 311 is cooled in the primary expansion inlet heat exchanger 620, and then enters the gas storage inlet and outlet heat exchanger 630 through the preheating water inlet pipeline 6331. The low-temperature heat storage medium after further cooling is returned to the low-temperature storage tank 312 for storage through the preheating return water pipeline 6341, thereby realizing the recycling of the heat storage medium.

[0068] This embodiment does not achieve the purpose of protecting equipment and pipelines by removing water carried in the air, but ensures that the air entering the pipeline and equipment is unsaturated air by forming a graded cooling system with the last compressor outlet heat exchanger 610 and the gas storage inlet and outlet heat exchanger 630, and forming a graded preheating system with the first expansion inlet heat exchanger 620 and the gas storage inlet and outlet heat exchanger 630, thereby slowing down corrosion; essentially, the water in the air is not removed, but condensation of water is avoided; the corrosion of the compressed air main pipe and the first expansion inlet heat exchanger 620 equipment by the low-temperature, high-pressure saturated humid air or salt-containing condensed water from the nth compressor 110 or the gas storage 410 is slowed down at a relatively low cost

[0069] Taking the configuration scheme of 8h compression energy storage and 4h expansion power generation as an example, the capacity of the compressed air system is about 50% of the capacity of the expansion power generation system; assuming that the incoming gas temperature of the salt cavern (gas storage reservoir 410) is 40°C, and the inlet air temperature of the expander 210 is 170°C; when adopting the scheme of this embodiment, assuming that the outlet temperature of the gas storage reservoir inlet and outlet heat exchanger 630 is 60°C, that is, the temperature rise is 20°C, and the area of ​​the gas storage reservoir inlet and outlet heat exchanger 630 is about 15% of the original heat exchanger; that is, the area of ​​the last-stage compressor outlet heat exchanger 610 can be reduced by about 15% of the area of ​​the first-stage expansion inlet heat exchanger 620; taking a 300MW compressed air energy storage power station as an example, the original first-stage expansion inlet heat exchanger 620 cost about 30 million yuan, and the first-stage expansion inlet heat exchanger 620 of this application can save about 4.5 million yuan.

[0070] Taking a 300MW compressed air energy storage power station as an example, the length of the compressed air pipeline is considered to be 1 kilometer; compared with the solution of increasing the corrosion allowance for corrosion prevention, the corrosion allowance is not considered after the solution of this embodiment is adopted, and the weight of the pipeline can be reduced by 40t. Considering the price of 15,000 yuan per ton of pipeline, about 600,000 yuan can be saved; compared with the solution of lining stainless steel for corrosion prevention, the lining stainless steel is not considered after the solution of this embodiment, and the unit price of the pipeline is reduced by 40%, which can save about 3 million yuan.

[0071] Example 2

[0072] like Figure 3 As shown: Based on Example 1, when m=n, the gas storage inlet and outlet heat exchanger 630 is connected to the last stage compressor outlet heat exchanger 610, the first stage expansion inlet heat exchanger 620 and the low-temperature storage tank 312.

[0073] The gas storage inlet and outlet heat exchangers 630 are connected to the last-stage compressor outlet heat exchanger 610 via a cooling return water shut-off valve 632, and the first-stage expansion inlet heat exchanger 620 is connected to the gas storage inlet and outlet heat exchangers 630 via a preheating water inlet shut-off valve 633; ​​the gas storage inlet and outlet heat exchangers 630 are connected to the low-temperature storage tank 312 via a cooling water inlet / preheating return water shut-off valve 635.

[0074] In the expansion power generation stage, the steps on the gas side are the same as those in Example 1;

[0075] Water side: when m=n, close the preheating water inlet shut-off valve 633, open the cooling water inlet / preheating water return shut-off valve 635 and the cooling water return shut-off valve 632; the low-temperature cooling water from the low-temperature storage tank 312 exchanges heat with the low-temperature air in the gas storage inlet and outlet heat exchanger 630 through the cooling water inlet / preheating water return pipeline 6351, and the heated cooling water returns to the final compressor outlet heat exchanger 610 through the cooling water return pipeline 6321 to cool down, thereby realizing the recycling of cooling water;

[0076] In the expansion power generation stage, the steps on the gas side are the same as those in Example 1;

[0077] Water side: when m=n, close the cooling return water shut-off valve 632, open the preheating water inlet shut-off valve 633 and the cooling water inlet / preheating return water shut-off valve 635; the high-temperature heat storage medium from the high-temperature storage tank 311 is cooled in the primary expansion inlet heat exchanger 620, and then enters the gas storage inlet and outlet heat exchanger 630 through the preheating water inlet pipeline 6331. The low-temperature heat storage medium after further cooling is returned to the low-temperature storage tank 312 for storage through the cooling water inlet / preheating return water pipeline 6351, thereby realizing the recycling of the heat storage medium.

[0078] Example 3

[0079] like Figure 4 As shown, this embodiment further includes a staged cooling / preheating system 600 on the basis of a conventional pressure storage solution, and the staged cooling / preheating system 600 includes a final compressor outlet heat exchanger 610, a primary expansion inlet heat exchanger 620, a gas storage inlet and outlet heat exchanger 630, a gas storage inlet and outlet separator 640, and an independent heat storage system 660;

[0080] The final compressor outlet heat exchanger 610 is connected to the outlet of the nth compressor 110; the first expansion inlet heat exchanger 620 is connected to the inlet of the first expansion machine 210;

[0081] The gas storage 410 is connected to the first compressed air main pipe 510 and the second compressed air main pipe 520 in sequence through the gas storage inlet and outlet separator 640 and the gas storage inlet and outlet heat exchanger 630 on the third compressed air main pipe 530;

[0082] The independent heat storage system 660 includes an independent low-heat storage tank 661 and an independent high-heat storage tank 662, and the independent low-heat storage tank 661 and the independent high-heat storage tank 662 are both connected to the gas storage inlet and outlet heat exchangers 630;

[0083] The high temperature storage tank 311 and the low temperature storage tank 312 are both connected to the final compressor outlet heat exchanger 610 and the primary expansion inlet heat exchanger 620 .

[0084] The independent low-heat storage tank 661 is connected to the gas storage inlet and outlet heat exchanger 630 through a low-temperature circulation pump 663 and a low-temperature circulation shut-off valve 665, and the independent high-heat storage tank 662 is connected to the gas storage inlet and outlet heat exchanger 630 through a high-temperature circulation pump 664 and a high-temperature circulation shut-off valve 666.

[0085] In actual use, each compressor 110 is driven by an independent motor or multiple compressors 110 are driven by a common motor; the expanders 210 at each stage drive the same generator to generate power. The number of stages of the expander 210 m = the number of compressor stages n-1 (see Figure 1 , Figure 2 ), or m = n (see Figure 3 ); the heat storage medium of the high temperature storage tank 311 and the low temperature storage tank 312 can be heat transfer oil, molten salt, water, solid particles or multiple heat storage media graded heat storage, etc. The high temperature storage tank 311 and the low temperature storage tank 312 can be horizontal tanks, vertical pipes or spherical tanks according to the heat storage medium; the gas storage reservoir 410 can be a salt cave type, artificial chamber type, mine cave type, pipeline steel or pressure vessel type gas storage reservoir, etc.

[0086] Conventional storage solutions such as Figure 5 and Figure 6 shown.

[0087] The last-stage compressor outlet heat exchanger 610 and the gas storage inlet and outlet heat exchanger 630 in the present invention form a graded cooling system; the heat exchange area of ​​the last-stage compressor outlet heat exchanger 610 in the present invention is smaller than that of the last-stage compressor outlet heat exchanger 610 of the conventional pressure storage scheme, and the outlet temperature of the last-stage compressor outlet heat exchanger 610 in the present invention is maintained above the saturation temperature and a certain margin is reserved (saturation temperature + 5°C), and then further cooled by the gas storage inlet and outlet heat exchanger 630 before entering the gas storage 410 for storage.

[0088] In the present invention, the first-stage expansion inlet heat exchanger 620 and the gas storage inlet and outlet heat exchanger 630 form a graded preheating system; the heat exchange area of ​​the first-stage expansion inlet heat exchanger 620 in the present invention is smaller than that of the first-stage expansion inlet heat exchanger 620 in the conventional pressure storage scheme; in the present invention, the low-temperature and high-pressure humid air from the gas storage 410 is first preheated to above the saturation temperature through the gas storage inlet and outlet heat exchanger 630 and a certain margin (saturation temperature + 10°C) is reserved, and then enters the first-stage expansion inlet heat exchanger 620 to continue to be heated to the rated temperature before entering the first-stage expander 210 to perform work.

[0089] The gas storage inlet and outlet heat exchangers 630 are arranged close to the gas storage 410, and can realize bidirectional flow on the air side and the heat storage medium side. The gas storage inlet and outlet heat exchangers 630 have two main functions:

[0090] 1) In the compression energy storage stage, the hierarchical cooling system composed of the gas storage inlet and outlet heat exchangers 630 and the final compressor outlet heat exchanger 610 cools down the high-pressure and high-temperature air at the outlet of the nth compressor 110 step by step, wherein the outlet air temperature of the final compressor outlet heat exchanger 610 is maintained above the saturation temperature, thereby preventing the air from cooling and condensing in the final compressor outlet heat exchanger 610 and the first compressed air main pipe 510, and preventing the occurrence of high-pressure oxygen corrosion; the high-pressure unsaturated wet air that has been initially cooled down by the final compressor outlet heat exchanger 610 continues to cool down in the gas storage inlet and outlet heat exchangers 630, and the temperature is reduced as much as possible. The temperature of the air entering the gas storage reservoir 410 is lowered (cooled to the gas storage reservoir inlet temperature of the conventional pressure storage scheme) to avoid excessive temperature rise of the air in the gas storage reservoir 410, which affects the gas storage capacity and sealing of the gas storage reservoir 410; the cooling medium of the last-stage compressor outlet heat exchanger 610 and the gas storage reservoir inlet and outlet heat exchanger 630 can be configured in parallel or in series; when the series configuration is adopted, the cooling medium first flows in reverse through the gas storage reservoir inlet and outlet heat exchanger 630, and then flows through the last-stage compressor outlet heat exchanger 610; when the parallel configuration is adopted, the cooling medium flows in parallel through the gas storage reservoir inlet and outlet heat exchangers 630 at the same time, and then flows through the last-stage compressor outlet heat exchanger 610.

[0091] 2) In the expansion energy release stage, the first-stage expansion inlet heat exchanger 620 and the gas storage inlet and outlet heat exchanger 630 form a graded preheating system to heat the saturated moist air or nearly saturated moist air from the gas storage 410 step by step to the rated temperature, wherein the gas storage inlet and outlet heat exchanger 630 can evaporate the small droplets (if any) carried in the air from the gas storage into water vapor, and ensure that the outlet air temperature is above the saturation temperature, thereby avoiding condensation of moist air in the third compressed air main pipe 530 and the second compressed air main pipe 520 and the first-stage expansion inlet heat exchanger 620 between the outlet of the gas storage inlet and outlet heat exchanger 630 and the first-stage expansion inlet heat exchanger 620, thereby preventing high-pressure oxygen corrosion; the unsaturated moist air preliminarily heated by the gas storage inlet and outlet heat exchanger 630 is further heated to the rated temperature in the first-stage expansion inlet heat exchanger 620 and then sent to the expander 210 to generate power.

[0092] Because the air intake of the first-stage expansion inlet heat exchanger 620 is unsaturated humid air and does not contain liquid water, the corrosion risk of the first-stage expansion inlet heat exchanger 620 is low, and the material in contact with the compressed air inside the heat exchanger can be reduced, thereby reducing the cost of the heat exchanger; the heating medium of the first-stage expansion inlet heat exchanger 620 and the gas storage inlet and outlet heat exchangers 630 can be configured in series or in parallel. The series configuration is recommended to reduce the system loss, thus improving system efficiency; when the heating medium adopts a series configuration scheme, the high-temperature heat storage medium from the high-temperature storage tank 311 first passes through the first-stage expansion inlet heat exchanger 620, and after cooling, the heat storage medium flows through the gas storage inlet and outlet heat exchanger 630 through valve switching, and then flows back to the low-temperature storage tank 312 after further cooling; the working conditions of the gas storage inlet and outlet heat exchanger 630 are harsh, and the low-temperature air side always works near or below the saturation temperature. The parts in the gas storage inlet and outlet heat exchanger 630 that are in contact with the compressed air are made of corrosion-resistant stainless steel.

[0093] The gas storage inlet and outlet separator 640 is arranged close to the gas storage 410 to achieve bidirectional flow. It has two functions:

[0094] 1) In the compression energy storage stage, the low-temperature saturated air from the gas storage inlet and outlet heat exchangers 630 is separated into gas and liquid through the gas storage inlet and outlet separators 640. The liquid water carried by the saturated wet air is separated and then enters the gas storage 410 for storage, so as to avoid the air entering the gas storage 410 carrying too much liquid water, which would affect the safe and stable operation of the gas storage 410 and the injection and production pipeline.

[0095] 2) During the expansion and energy release stage, the saturated wet air or nearly saturated wet air or wet air carrying impurities from the gas storage reservoir 410 is separated into gas-liquid and gas-solid through the gas storage reservoir inlet and outlet separators 640, and the liquid droplets and solid particles carried in the air are separated to avoid the subsequent process air carrying too many liquid droplets and solid particles, thereby optimizing the working conditions of the subsequent ground facilities.

[0096] The gas storage inlet and outlet separators 640 may use cyclone separation or baffle separators; the working conditions of the gas storage inlet and outlet separators 640 are harsh, and they always work near or below the saturation temperature. The parts in the gas storage inlet and outlet separators 640 that are in contact with the compressed air are made of corrosion-resistant stainless steel or lined with stainless steel.

[0097] The air side pipeline of the graded cooling / preheating system 600 includes the air pipes and valves between the inlet and outlet of the gas storage reservoir 410 and the inlet and outlet heat exchanger 630 of the gas storage reservoir. This section of the pipeline always operates near or below the saturation temperature. The length of this section of the pipeline is relatively short. In order to ensure the safe and stable operation of the system, the pipeline adopts a solution of increasing the corrosion margin or lining with stainless steel or organic matter to ensure the corrosion resistance of the pipeline.

[0098] The water side pipeline of the graded cooling / preheating system 600 includes a graded cooling water side pipeline and a graded preheating water side pipeline; when m=n-1, such as Figure 1As shown, the graded cooling water side pipeline includes a cooling water inlet pipeline 6311 and a cooling water inlet shut-off valve 631, a cooling water return pipeline 6321 and a cooling water return shut-off valve 632, and the graded preheating water side pipeline includes a preheating water inlet pipeline 6331 and a preheating water inlet shut-off valve 633, a preheating water return pipeline 6341 and a preheating water return shut-off valve 634; when m=n, as Figure 2 As shown, the graded cooling water side pipeline includes a cooling water inlet / preheating water return pipeline 6351 and a cooling water inlet / preheating water return shut-off valve 635, a cooling water return pipeline 6321 and a cooling water return shut-off valve 632, and the graded preheating water side pipeline includes a preheating water inlet pipeline 6331 and a preheating water inlet shut-off valve 633, a cooling water inlet / preheating water return pipeline 6351 and a cooling water inlet / preheating water return shut-off valve 635;

[0099] like Figure 3 As shown, the graded cooling / preheating system 600 may also be provided with an independent heat storage system 660. Since the operating temperature of the inlet and outlet heat exchangers 630 of the gas storage reservoir is relatively low, it is recommended that the independent low-heat storage tank 661 and the independent high-heat storage tank 662 adopt normal pressure vertical or horizontal storage tanks to reduce the system cost.

[0100] In summary, the present invention solves the problem of a significant increase in the cost of pipelines caused by thicker walls or the use of anti-corrosion materials such as stainless steel or organic materials as inner linings between the outlet of the nth stage compressor 110 and the inlet of the gas storage reservoir 410, and between the outlet of the gas storage reservoir 410 and the inlet of the first-stage expander 210 in the existing compressed air energy storage power station due to the large corrosion margin of the large-diameter compressed air main pipe, thereby further improving the economy of the compressed air energy storage power station.

[0101] The present invention solves the problem of significantly increased cost of heat exchanger equipment caused by the use of corrosion-resistant stainless steel materials for corrosion prevention in the final compressor outlet heat exchanger 610 and the first-stage expansion inlet heat exchanger 620 in the existing compressed air energy storage power station, thereby further improving the economy of the compressed air energy storage power station.

[0102] The present invention solves the problems of long corrosion risk process and many corrosion risk points in existing compressed air energy storage power stations, and further improves the safe, stable and reliable operation of compressed air energy storage power stations.

[0103] Other parts not described belong to the prior art.

Claims

1. A system for mitigating corrosion of ground facilities of a compressed gas storage power station, comprising a compressed air system (100), an expansion power generation system (200), a heat storage and exchange system (300) and a gas storage system (400), wherein the compressed air system (100) comprises n-stage compressors (110) connected in series, where n≥2; the expansion power generation system (200) comprises m-stage expanders (210) connected in series, where m≥2; the heat storage and exchange system (300) comprises a heat storage system (310) and a heat exchange system (320); the heat storage system (310) comprises at least one high-temperature storage tank (311) and at least one low-temperature storage tank (312), wherein the high-temperature storage tank (311) and the low-temperature storage tank (312) are both connected to a heat exchange system (320); the heat exchange system (320) is arranged between n compressors (110) connected in series and between m expanders (210) connected in series; the gas storage system (400) comprises a gas storage (410), the nth compressor (110) is connected to a third compressed air main pipe (530) via a first compressed air main pipe (510), the first-stage expander (210) is connected to a third compressed air main pipe (530) via a second compressed air main pipe (520), and the third compressed air main pipe (530) is connected to the gas storage (410); Features: The system also includes a staged cooling / preheating system (600), wherein the staged cooling / preheating system (600) includes a final compressor outlet heat exchanger (610), a primary expansion inlet heat exchanger (620), a gas storage inlet and outlet heat exchanger (630), and a gas storage inlet and outlet separator (640); The final compressor outlet heat exchanger (610) is connected to the outlet of the nth compressor (110); the first expansion inlet heat exchanger (620) is connected to the inlet of the first expansion machine (210); The air storage (410) is connected to the first compressed air main pipe (510) and the second compressed air main pipe (520) in sequence through the air storage inlet and outlet separator (640) and the air storage inlet and outlet heat exchanger (630) on the third compressed air main pipe (530); When m=n-1, the cooling tower (700) is connected to the final compressor outlet heat exchanger (610) and the gas storage inlet and outlet heat exchanger (630); the gas storage inlet and outlet heat exchanger (630) is connected to the primary expansion inlet heat exchanger (620) and the low-temperature storage tank (312); When m=n, the gas storage inlet and outlet heat exchangers (630) are connected to the final compressor outlet heat exchanger (610), the primary expansion inlet heat exchanger (620) and the cryogenic storage tank (312).

2. A system for mitigating corrosion of ground facilities of a pressure storage power station according to claim 1, characterized in that: When m=n-1 and the cooling medium of the final compressor outlet heat exchanger (610) and the gas storage inlet and outlet heat exchanger (630) are arranged in parallel, the medium outlet of the cooling tower (700) is connected to the gas storage inlet and outlet heat exchanger (630) through a cooling water inlet shut-off valve (631), and the medium inlet of the cooling tower (700) is connected to the gas storage inlet and outlet heat exchanger (630) through a cooling return water shut-off valve (632); the first-stage expansion inlet heat exchanger (620) is connected to the gas storage inlet and outlet heat exchanger (630) through a preheating water inlet shut-off valve (633); and the gas storage inlet and outlet heat exchanger (630) is connected to a low-temperature storage tank (312) through a preheating return water shut-off valve (634).

3. A system for mitigating corrosion of ground facilities of a pressure storage power station according to claim 2, characterized in that: When m=n-1 and the cooling medium of the last-stage compressor outlet heat exchanger (610) and the gas storage inlet and outlet heat exchanger (630) are arranged in series, the medium outlet of the cooling tower (700) is connected to the gas storage inlet and outlet heat exchanger (630) via a cooling water inlet shut-off valve (631), the gas storage inlet and outlet heat exchanger (630) is connected to the medium inlet of the last-stage compressor outlet heat exchanger (610) via a cooling water return shut-off valve (632), and the medium outlet of the last-stage compressor outlet heat exchanger (610) is connected to the medium inlet of the cooling tower (700).

4. A system for mitigating corrosion of ground facilities of a pressure storage power station according to claim 1, characterized in that: When m=n, the gas storage inlet and outlet heat exchangers (630) are connected to the final compressor outlet heat exchanger (610) via a cooling return water shut-off valve (632); the primary expansion inlet heat exchanger (620) is connected to the gas storage inlet and outlet heat exchangers (630) via a preheating inlet water shut-off valve (633); the gas storage inlet and outlet heat exchangers (630) are connected to the low-temperature storage tank (312) via a cooling inlet water / preheating return water shut-off valve (635).

5. A system for mitigating corrosion of ground facilities of a compressed gas storage power station, comprising a compressed air system (100), an expansion power generation system (200), a heat storage and exchange system (300) and a gas storage system (400), wherein the compressed air system (100) comprises n-stage compressors (110) connected in series, where n≥2; the expansion power generation system (200) comprises m-stage expanders (210) connected in series, where m≥2; the heat storage and exchange system (300) comprises a heat storage system (310) and a heat exchange system (320); the heat storage system (310) comprises at least one high-temperature storage tank (311) and at least one low-temperature storage tank (312), wherein the high-temperature storage tank (311) and the low-temperature storage tank (312) are both connected to a heat exchange system (320); the heat exchange system (320) is arranged between n compressors (110) connected in series and between m expanders (210) connected in series; the gas storage system (400) comprises a gas storage (410), the nth compressor (110) is connected to a third compressed air main pipe (530) via a first compressed air main pipe (510), the first-stage expander (210) is connected to a third compressed air main pipe (530) via a second compressed air main pipe (520), and the third compressed air main pipe (530) is connected to the gas storage (410); Features: The system also includes a staged cooling / preheating system (600), wherein the staged cooling / preheating system (600) includes a final compressor outlet heat exchanger (610), a primary expansion inlet heat exchanger (620), a gas storage inlet and outlet heat exchanger (630), a gas storage inlet and outlet separator (640), and an independent heat storage system (660); The final compressor outlet heat exchanger (610) is connected to the outlet of the nth compressor (110); the first expansion inlet heat exchanger (620) is connected to the inlet of the first expansion machine (210); The air storage (410) is connected to the first compressed air main pipe (510) and the second compressed air main pipe (520) in sequence through the air storage inlet and outlet separator (640) and the air storage inlet and outlet heat exchanger (630) on the third compressed air main pipe (530); The independent heat storage system (660) comprises an independent low-heat storage tank (661) and an independent high-heat storage tank (662), and the independent low-heat storage tank (661) and the independent high-heat storage tank (662) are both connected to the gas storage inlet and outlet heat exchangers (630); The high-temperature storage tank (311) and the low-temperature storage tank (312) are both connected to the final compressor outlet heat exchanger (610) and the primary expansion inlet heat exchanger (620).

6. A system for mitigating corrosion of ground facilities of a pressure storage power station according to claim 5, characterized in that: The independent low-heat storage tank (661) is connected to the gas storage inlet and outlet heat exchanger (630) via a low-temperature circulation pump (663) and a low-temperature circulation shut-off valve (665), and the independent high-heat storage tank (662) is connected to the gas storage inlet and outlet heat exchanger (630) via a high-temperature circulation pump (664) and a high-temperature circulation shut-off valve (666).

7. A system for mitigating corrosion of ground facilities of a pressure storage power station according to claim 1 or 5, characterized in that: The gas storage reservoir (410) is connected to the gas storage inlet and outlet separator (640) via the gas storage shut-off valve (420); the final compressor outlet heat exchanger (610) is connected to the first compressed air main pipe (510) via the compression side shut-off valve (611); the second compressed air main pipe (520) is connected to the first expansion inlet heat exchanger (620) via the expansion side shut-off valve (621).

8. A system for mitigating corrosion of ground facilities of a pressure storage power station according to claim 1 or 5, characterized in that: The gas storage inlet and outlet heat exchanger (630) and the gas storage inlet and outlet separator (640) are arranged adjacent to the gas storage (410).

9. A method for operating a system for mitigating corrosion of ground facilities of a pressure storage power station, characterized in that: It includes a compression energy storage stage and an expansion power generation stage; The compression energy storage stage comprises the following steps: On the gas side: the expansion side shut-off valve (621) is closed, and the compression side shut-off valve (611) and the gas storage shut-off valve (420) are opened; the high-temperature and high-pressure air at the outlet of the nth stage compressor (110) is cooled to a temperature above the saturation temperature through the heat exchanger (610) at the outlet of the last stage compressor, and then flows into the gas storage inlet and outlet heat exchanger (630) through the first compressed air main pipe (510), and continues to be cooled in the gas storage inlet and outlet heat exchanger (630), and then enters the gas storage (410) for storage after liquid water is separated by the gas storage inlet and outlet separator (640); Water side: when m=n-1, close the preheating return water shutoff valve (634) and the preheating inlet water shutoff valve (633), and open the cooling inlet water shutoff valve (631) and the cooling return water shutoff valve (632); the low-temperature cooling water from the cooling tower (700) exchanges heat with the low-temperature air in the gas storage inlet and outlet heat exchangers (630) through the cooling inlet water pipeline (6311); after the temperature is increased, the cooling water returns to the cooling tower (700) through the cooling return water pipeline (6321) to cool down, thereby realizing the recycling of cooling water; When m=n, the preheating water inlet shutoff valve (633) is closed, and the cooling water inlet / preheating water return shutoff valve (635) and the cooling water return shutoff valve (632) are opened; the low-temperature cooling water from the low-temperature storage tank (312) exchanges heat with the low-temperature air in the gas storage inlet and outlet heat exchangers (630) through the cooling water inlet / preheating water return pipeline (6351); after the temperature is increased, the cooling water returns to the final compressor outlet heat exchanger (610) through the cooling water return pipeline (6321) to cool down, thereby realizing the recycling of cooling water; The expansion power generation stage comprises the following steps: On the gas side: the compression side shut-off valve (611) is closed, and the expansion side shut-off valve (621) and the gas storage shut-off valve (420) are opened; the saturated wet air or nearly saturated wet air or wet air carrying impurities from the gas storage (410) is separated into liquid droplets or solid particles by the gas storage inlet and outlet separator (640), and then enters the gas storage inlet and outlet heat exchanger (630), is heated to a temperature above the saturation temperature by the heat storage medium in the gas storage inlet and outlet heat exchanger (630), and then enters the first-stage expander (210) through the second compressed air main pipe (520), is further heated to a rated temperature by the heat storage medium, and then enters the expander (210) to generate power; Water side: when m=n-1, the cooling water inlet shutoff valve (631) and the cooling water return shutoff valve (632) are closed, and the preheating water return shutoff valve (634) and the preheating water inlet shutoff valve (633) are opened; the high-temperature heat storage medium from the high-temperature storage tank (311) is cooled in the primary expansion inlet heat exchanger (620), and then enters the gas storage inlet and outlet heat exchanger (630) through the preheating water inlet pipeline (6331), and the low-temperature heat storage medium after further cooling is returned to the low-temperature storage tank (312) for storage through the preheating water return pipeline (6341), thereby realizing the recycling of the heat storage medium; When m=n, the cooling return water shut-off valve (632) is closed, and the preheating water shut-off valve (633) and the cooling water / preheating return water shut-off valve (635) are opened; the high-temperature heat storage medium from the high-temperature storage tank (311) is cooled in the primary expansion inlet heat exchanger (620), and then enters the gas storage inlet and outlet heat exchanger (630) through the preheating water inlet pipeline (6331); the low-temperature heat storage medium after further cooling is returned to the low-temperature storage tank (312) for storage through the cooling water / preheating return water pipeline (6351), thereby realizing the recycling of the heat storage medium.

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