Liquid air energy storage system based on the transformation of retired coal-fired units

Abstract

This utility model discloses a liquid air energy storage system based on the retrofitting of decommissioned coal-fired power units, including a new equipment unit and a coal-fired power unit equipment reuse unit. The new equipment unit includes a first compressor, a second compressor, a liquefaction main heat exchanger, a cold storage device, a liquid storage tank, and an evaporator. The coal-fired power unit equipment reuse unit includes a low-temperature water storage tank, a first low-pressure cooler, a second high-pressure cooler, a high-temperature heat storage tank, a high-pressure reheater, a low-pressure reheater, an air expander, and a generator. This utility model combines decommissioned coal-fired power units with liquid air energy storage technology. By utilizing and retrofitting some of the original equipment of the decommissioned coal-fired power units, and by adding equipment units, the charging and discharging functions of the liquid air energy storage system are realized, providing effective support services for the power grid. This solves the problems of idle and wasted decommissioned coal-fired power unit equipment and the high cost and difficulty in implementing new liquid energy storage power plants.

Description

Technical Field

[0001] This utility model relates to liquid air energy storage systems, specifically to a liquid air energy storage system based on the retrofitting of decommissioned coal-fired power units. Background Technology

[0002] In my country's current power system, there are nearly 900 subcritical generating units of 300MW or higher. Most of these units were put into operation relatively early and are nearing the end of their design service life. To further reduce total carbon emissions, they will gradually enter the shutdown phase. Many of these units are located in power load centers and have long played a crucial regulatory role in ensuring regional power supply and demand balance, supporting stable system operation, and responding to load fluctuations. Some units also undertake heat load tasks such as industrial heating or residential heating, playing an important role in integrated energy services. With the arrival of the decommissioning wave of coal-fired units, these decommissioned units are usually idle, and their corresponding power transmission channels cannot be effectively utilized.

[0003] Liquid air energy storage is an energy storage technology with advantages in long-term energy storage and flexible thermoelectric output. Compared with compressed air energy storage, liquid air energy storage does not require the construction of gas storage facilities. However, the construction of liquid air energy storage power plants faces problems such as high cost and difficulty in implementation.

[0004] Liquid air energy storage systems have a high degree of compatibility with the power generation cycle characteristics of coal-fired power units, and the two have a natural matching advantage. Converting retired coal-fired power units into liquid air energy storage power stations can not only provide support services for the power grid, but also effectively utilize the existing resources and power transmission advantages of coal-fired power units.

[0005] Currently, there is no existing technology for applying retired coal-fired power units to liquid air energy storage systems. The usual approach is to combine in-service coal-fired power units with liquid air energy storage technology, using the heat of liquid air compression and the energy recovered from the waste heat during the operation of the coal-fired power unit to provide energy for the expander. The expander then drives the generator to produce electricity. Therefore, there is a need for a technical solution that can retrofit and utilize retired coal-fired power units and combine them with liquid air energy storage systems to provide support services for the power grid. Utility Model Content

[0006] The technical problem this utility model aims to solve is to provide a liquid air energy storage system based on the retrofitting of decommissioned coal-fired power units. This system can retrofit decommissioned coal-fired power units and apply them to the liquid air energy storage system, making full use of existing coal-fired power unit sites, equipment resources, and power transmission systems to provide effective support services for the power grid. This solves the problems of idle and wasteful decommissioned coal-fired power unit equipment and the high cost and difficulty in implementing new liquid energy storage power plants.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows.

[0008] The liquid air energy storage system based on the retrofitting of decommissioned coal-fired power units includes a new equipment unit and a coal-fired power unit equipment reuse unit. The new equipment unit includes a first compressor, a second compressor, a liquefaction main heat exchanger, a cold storage device, a liquid storage tank, and an evaporator. The coal-fired power unit equipment reuse unit includes a low-temperature water storage tank, a first low-pressure cooler, a second high-pressure cooler, a high-temperature heat storage tank, a high-pressure reheater, a low-pressure reheater, an air expander, and a generator. The first compressor, the first low-pressure cooler, the second compressor, the second high-pressure cooler, the liquefaction main heat exchanger, the liquid storage tank, and the evaporator are connected in series. The evaporator is connected to the high-pressure reheater, the high-pressure reheater and the low-pressure reheater are respectively connected to the air expander, and the air expander is connected to the generator. The low-temperature water storage tank is connected to the first low-pressure cooler and the second high-pressure cooler, and the first low-pressure cooler and the second high-pressure cooler are respectively connected to the high-temperature heat storage tank. The output end of the high-temperature heat storage tank is connected to the water-side input end of the high-pressure reheater and the low-pressure reheater.

[0009] The aforementioned liquid air energy storage system based on the retrofit of decommissioned coal-fired power units has the following connection: the gas-side outlet of the first compressor is connected to the gas-side input of the first low-pressure cooler; the gas-side output of the first low-pressure cooler is connected to the gas-side input of the second compressor; the gas-side outlet of the second compressor is connected to the gas-side input of the second high-pressure cooler; the gas-side output of the second high-pressure cooler is connected to the input of the liquefaction main heat exchanger; the output of the liquefaction main heat exchanger is connected to the input of the liquid storage tank; and the liquefaction main heat exchanger is connected to the cold release end of the cold storage device.

[0010] In the aforementioned liquid air energy storage system based on the retrofitting of decommissioned coal-fired power units, the output end of the low-temperature water storage device is connected to the water-side input ends of the first low-pressure cooler and the second high-pressure cooler, respectively, and the water-side output ends of the first low-pressure cooler and the second high-pressure cooler are connected to the input ends of the high-temperature heat storage device, respectively.

[0011] The liquid air energy storage system described above, which is based on the retrofitting of decommissioned coal-fired power units, has a hot water pump installed at the outlet of the low-temperature water storage tank.

[0012] The aforementioned liquid air energy storage system based on the retrofitting of decommissioned coal-fired power units includes a multi-stage air expander. The output end of the evaporator is connected to the gas-side input end of the high-pressure reheater, and the gas-side output end of the high-pressure reheater is connected to the input end of the air expander. The interstage exhaust outlet of the air expander is connected to the gas-side input end of the low-pressure reheater, and the gas-side output end of the low-pressure reheater is connected to the input end of the air expander below the interstage exhaust outlet connected to the gas-side input end of the low-pressure reheater.

[0013] The aforementioned liquid air energy storage system based on the retrofitting of decommissioned coal-fired power units also includes a booster pump installed at the liquid air outlet of the storage tank.

[0014] In the aforementioned liquid air energy storage system based on the retrofitting of decommissioned coal-fired power units, the cold storage end of the cold storage device is connected to the evaporator.

[0015] The aforementioned liquid air energy storage system based on the retrofitting of decommissioned coal-fired power units includes a first compressor motor connected to a first compressor and a second compressor motor connected to a second compressor. A first energy storage circuit breaker for controlling the first compressor is installed on the power input line of the first compressor motor, and a second energy storage circuit breaker for controlling the second compressor is installed on the power input line of the second compressor motor. The first and second energy storage circuit breakers are connected in parallel and then connected to an energy storage transformer. The energy storage transformer is connected to the output of the generator.

[0016] The aforementioned liquid air energy storage system based on the retrofitting of decommissioned coal-fired power units includes a coal-fired power unit equipment reuse unit that also includes an energy release circuit breaker, a high-voltage plant transformer, a plant power bus, a step-up substation, and a high-voltage bus of the coal-fired power unit. The energy release circuit breaker is located at the generator outlet, and the generator outlet is connected to the high-voltage plant transformer and the step-up substation, respectively. The high-voltage plant transformer and the step-up substation are connected in parallel with the energy storage transformer.

[0017] The liquid air energy storage system described above, which is based on the retrofitting of decommissioned coal-fired power units, has a high-voltage plant transformer connected to the plant power bus, and a plant power circuit breaker is installed on the plant power bus.

[0018] The technological advancements achieved by this utility model are as follows, due to the adoption of the above technical solutions.

[0019] This utility model provides a liquid air energy storage system based on the retrofitting of decommissioned coal-fired power units. It combines decommissioned coal-fired power units with liquid air energy storage technology. By utilizing and retrofitting some of the original equipment of the decommissioned coal-fired power units, and by adding new equipment units, the charging and discharging functions of the liquid air energy storage system are realized. It provides effective support services for the power grid and solves the problems of idle and wasteful decommissioned coal-fired power unit equipment and high cost and difficulty in implementing new liquid energy storage power plants.

[0020] During the energy storage and discharge process, the compressor, cooler, liquefaction main heat exchanger, cold storage device, and liquid storage tank work together to complete the entire process of air changing from a gaseous state to a liquid state. The liquefied air is stored in the liquid storage tank, and the heat of compression during the compression process is effectively recovered for use in the energy release stage.

[0021] During the energy release and charging process, liquid air is pressurized and vaporized by the cooperation of an evaporator, a reheater, a high-temperature accumulator, and an air expander. The vaporized air is then sent to the reheater for heating and then sent to the air expander to use the kinetic energy of the heated air to expand and do work, driving the generator to generate electricity. At the same time, the cold energy generated during the vaporization process is stored for use in the energy storage stage. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the specific structure of this utility model.

[0023] Among them: 100. New equipment unit, 101. First compressor motor, 102. First compressor, 103. Second compressor motor, 104. Second compressor, 105. Liquefaction main heat exchanger, 106. Cold storage device, 107. Liquid storage tank, 108. Pressurization pump, 109. Evaporator, 110. First energy storage circuit breaker, 111. Second energy storage circuit breaker, 112. Energy storage transformer; 200. Coal-fired unit equipment reuse unit; 201. Low-temperature water storage tank; 202. Hot water storage pump; 203. First low-pressure cooler; 204. Second high-pressure cooler; 205. High-temperature heat accumulator; 206. High-pressure reheater; 207. Low-pressure reheater; 208. Air expander; 209. Generator; 210. Energy release circuit breaker; 211. High-voltage station service transformer; 212. Station service circuit breaker; 213. Station service busbar; 214. Substation; 215. High-voltage busbar of coal-fired unit. Detailed Implementation

[0024] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0025] Liquid air energy storage systems based on the retrofitting of decommissioned coal-fired power units, such as Figure 1 As shown, the system includes a new equipment unit 100 and a coal-fired power unit equipment reuse unit 200. The new equipment unit 100 and the coal-fired power unit equipment reuse unit 200 together constitute a liquid air energy storage system.

[0026] The newly added equipment unit 100 includes a first compressor 102, a second compressor 104, a liquefaction main heat exchanger 105, a cold storage device 106, a liquid storage tank 107, and an evaporator 109. The output end of the liquefaction main heat exchanger 105 is connected to the input end of the liquid storage tank 107, and the output end of the liquid storage tank 107 is connected to the input end of the evaporator 109.

[0027] A pressurizing pump 108 is also installed at the liquid air outlet of the liquid storage tank 107 to pressurize the liquid air so that it can be vaporized in the evaporator and release low-temperature cold energy.

[0028] The liquefaction main heat exchanger 105 is connected to the cold release end of the cold storage device 106, and the cold energy required for liquefaction is provided to the liquefaction main heat exchanger 105 through the cold storage device 106.

[0029] The cold storage end of the cold storage device 106 is connected to the evaporator 109. After the liquefied air enters the evaporator 109, the cold storage device 106 can absorb the low-temperature cold energy released after the liquefied air is vaporized.

[0030] Specifically, during the power generation process, the cold storage device absorbs and stores the cold energy from the vaporization of liquid air, and releases the cold energy into the liquefaction main heat exchanger 105 during the charging process to provide cooling for air liquefaction.

[0031] The newly added equipment unit 100 also includes a first compressor motor 101 connected to the first compressor 102 and a second compressor motor 103 connected to the second compressor 104. A first energy storage circuit breaker 110 for controlling the first compressor 102 is provided on the power input line of the first compressor motor 101, and a second energy storage circuit breaker 111 for controlling the second compressor 104 is provided on the power input line of the second compressor motor 103.

[0032] The first energy storage circuit breaker 110 and the second energy storage circuit breaker 111 are connected in parallel and are ultimately connected to the energy storage transformer 112 to realize the start-stop control of the first compressor 102 and the second compressor 104.

[0033] The coal-fired power unit equipment reuse unit 200 includes a low-temperature water storage tank 201, a first low-pressure cooler 203, a second high-pressure cooler 204, a high-temperature heat storage tank 205, a high-pressure reheater 206, a low-pressure reheater 207, an air expander 208, and a generator 209.

[0034] The output end of the low-temperature water storage device 201 is connected to the water-side input end of the first low-pressure cooler 203 and the second high-pressure cooler 204, respectively. The water-side output ends of the first low-pressure cooler 203 and the second high-pressure cooler 204 are connected to the input end of the high-temperature heat storage device 205, respectively.

[0035] The outlet of the low-temperature water storage tank 201 is equipped with a hot water storage pump 202, which is used to send low-temperature water into the first low-pressure cooler 203 and the second high-pressure cooler 204, and convert it into high-temperature water for storage in the high-temperature heat storage tank 205.

[0036] The gas-side input end of the first low-pressure cooler 203 is connected to the gas-side outlet end of the first compressor 102, and the gas-side output end of the first low-pressure cooler 203 is connected to the input end of the second compressor 104. It is used to cool the exhaust gas of the first compressor 102 and send it into the second compressor 104 for secondary compression.

[0037] The gas-side outlet of the second compressor 104 is connected to the gas-side input of the second high-pressure cooler 204, and the gas-side output of the second high-pressure cooler 204 is connected to the input of the liquefaction main heat exchanger 105. This is used to cool the exhaust gas of the second compressor 104 and send it into the liquefaction main heat exchanger 105, where the compressed air is liquefied.

[0038] The output end of the high-temperature heat storage device 205 is connected to the water-side input end of the high-pressure reheater 206 and the low-pressure reheater 207, respectively. The water-side output ends of the high-pressure reheater 206 and the low-pressure reheater 207 are connected to the input end of the low-temperature water storage device 201, respectively.

[0039] The gas-side input terminal of the high-pressure reheater 206 is connected to the output terminal of the evaporator 109, and the gas-side output terminal of the high-pressure reheater 206 is connected to the input terminal of the air expander 208.

[0040] The air expander 208 is a multi-stage air expander. The interstage exhaust outlet of the air expander 208 is connected to the air-side input end of the low-pressure reheater 207. The air-side output end of the low-pressure reheater 207 is connected to the input end of the air expander 208 below the interstage exhaust outlet connected to the air-side input end of the low-pressure reheater 207.

[0041] The air expander 208 is connected to the generator 209 and drives the generator to generate electricity. Specifically, after the liquid air is vaporized, it is sent into the high-pressure reheater 206 and the low-pressure reheater 207 for heating. The kinetic energy generated by the expansion of the heated air drives the generator to generate electricity.

[0042] The coal-fired power unit equipment reuse unit 200 also includes an energy release circuit breaker 210, a high-voltage plant transformer 211, a plant power busbar 213, a step-up substation 214, and a coal-fired power unit high-voltage busbar 215.

[0043] The energy release circuit breaker 210 is installed at the outlet of the generator 209 to realize grid connection control during the energy release power generation process.

[0044] The generator 209 is connected to the high-voltage plant transformer 211, the step-up substation 214, and the energy storage transformer 112 respectively. The high-voltage plant transformer 211, the step-up substation 214, and the energy storage transformer 112 are connected in parallel.

[0045] The high-voltage plant transformer 211 is connected to the plant power bus 213, and the plant power bus 213 is equipped with a plant power circuit breaker 212.

[0046] In this embodiment, the first compressor 102, the first low-pressure cooler 203, the second compressor 104, the second high-pressure cooler 204, the liquefaction main heat exchanger 105, the liquid storage tank 107, and the evaporator 109 are connected in series. During energy storage and discharge, air enters the first compressor, is compressed, and then sent to the first low-pressure cooler for low-pressure cooling. It is then compressed again by the second compressor and sent to the second high-pressure cooler for further cooling. The compressed and cooled air enters the liquefaction main heat exchanger, where it is provided with cold energy by a cold storage device to complete the air liquefaction process. At the same time, the heat from the compression process is recovered and stored by a high-temperature heat accumulator.

[0047] Evaporator 109 is connected to high-pressure reheater 206. High-pressure reheater 206 and low-pressure reheater 207 are respectively connected to air expander 208. Air expander 208 is connected to generator 209. Liquid air in the storage tank is pressurized by a pressurizing pump and sent to the evaporator for vaporization. During this process, the cold energy in the vaporization process is absorbed by a cold storage device. Then, the high-pressure air is sent to the high-pressure reheater. The waste heat recovered in the high-temperature heat storage device is used to heat the high-pressure air and send it to the multi-stage air expander. At the same time, the interstage exhaust of the air expander is also sent to the low-pressure reheater for heating. The heated air is then sent back to the air expander to expand and do work to drive the generator to generate electricity.

[0048] In this embodiment, the coal-fired power unit equipment reuse unit 200 is derived from the reuse or modification of the original equipment of the coal-fired power unit, making full use of the original equipment of the retired coal-fired power unit.

[0049] Specifically, the cryogenic water storage unit 201 is a modified condenser from a decommissioned coal-fired power unit, which enables the storage of cryogenic water and saves investment in the cryogenic water storage section of the liquid air energy storage system.

[0050] The hot water storage pump 202 is a direct reuse of the condensate pump of a decommissioned coal-fired power unit. The condensate pump of the decommissioned coal-fired power unit is located below the condenser and does not require modification. The equipment and pipelines can be used directly, saving investment in the hot water storage pump 202 and some pipelines in the liquid air energy storage system.

[0051] The first low-pressure cooler 203 and the low-pressure reheater 207 are low-pressure heaters in decommissioned coal-fired power units. Accordingly, they are selected from low-pressure heaters No. 5 to No. 8 in the regenerative system of decommissioned coal-fired power units, based on the exhaust pressure of the first compressor 102 and the interstage exhaust pressure of the air expander 208. This saves investment in energy storage process coolers and power generation process heaters in liquid air energy storage systems.

[0052] The second high-pressure cooler 204 and the high-pressure reheater 206 are high-pressure heaters in the decommissioned coal-fired power units. Accordingly, they are selected from the No. 1 to No. 3 high-pressure heaters in the regenerative system of the decommissioned coal-fired power units, based on the exhaust pressure of the second compressor 104 and the inlet pressure of the air expander 208. This also saves investment in the energy storage process cooler and the power generation process heater in the liquid air energy storage system.

[0053] The high-temperature thermal accumulator 205 was converted from the boiler of a decommissioned coal-fired unit, saving investment in the high-temperature thermal storage part of the liquid air energy storage system.

[0054] The 208 air expander was converted from a steam turbine of a decommissioned coal-fired unit, saving the investment in expanders in liquid air energy storage systems.

[0055] Generator 209 is an original generator from a decommissioned coal-fired unit, saving investment in the generator portion of the liquid air energy storage system.

[0056] The high-voltage plant transformer 211, plant circuit breaker 212, and plant busbar 213 are the original configurations of the decommissioned coal-fired power units. The power supply for the newly added auxiliary equipment in the liquid air energy storage system is all drawn from the plant busbar 213.

[0057] This utility model combines retired coal-fired power units with liquid air energy storage technology. By utilizing and modifying some of the original equipment of retired coal-fired power units, and by adding new equipment units, the charging and discharging functions of the liquid air energy storage system are realized, providing effective support services for the power grid. This solves the problems of idle and wasteful retired coal-fired power unit equipment and the high cost and difficulty in implementing new liquid energy storage power plants.

[0058] During the energy storage and discharge process, the compressor, cooler, liquefaction main heat exchanger, cold storage device, and liquid storage tank work together to complete the entire process of air changing from a gaseous state to a liquid state. The liquefied air is stored in the liquid storage tank, and the heat of compression during the compression process is effectively recovered for use in the energy release stage.

[0059] During the energy release and charging process, liquid air is pressurized and vaporized by the cooperation of an evaporator, a reheater, a high-temperature accumulator, and an air expander. The vaporized air is then sent to the reheater for heating and then sent to the air expander to use the kinetic energy of the heated air to expand and do work, driving the generator to generate electricity. At the same time, the cold energy generated during the vaporization process is stored for use in the energy storage stage.

Claims

1. A liquid air energy storage system based on the retrofitting of decommissioned coal-fired power units, characterized in that: The system includes a new equipment unit (100) and a coal-fired power unit equipment reuse unit (200). The new equipment unit (100) includes a first compressor (102), a second compressor (104), a liquefaction main heat exchanger (105), a cold storage device (106), a liquid storage tank (107), and an evaporator (109). The coal-fired power unit equipment reuse unit (200) includes a low-temperature water storage tank (201), a first low-pressure cooler (203), a second high-pressure cooler (204), a high-temperature heat storage tank (205), a high-pressure reheater (206), a low-pressure reheater (207), an air expander (208), and a generator (209). The first compressor (102), the first low-pressure cooler (203), the second compressor (104), and the second high-pressure cooler (209) are also included. The heat exchanger (204), the liquefaction main heat exchanger (105), the liquid storage tank (107), and the evaporator (109) are connected in series. The evaporator (109) is connected to the high-pressure reheater (206), the high-pressure reheater (206) and the low-pressure reheater (207) are respectively connected to the air expander (208), and the air expander (208) is connected to the generator (209). The low-temperature water storage tank (201) is respectively connected to the first low-pressure cooler (203) and the second high-pressure cooler (204), and the first low-pressure cooler (203) and the second high-pressure cooler (204) are respectively connected to the high-temperature heat storage tank (205). The output end of the high-temperature heat storage tank (205) is respectively connected to the water-side input end of the high-pressure reheater (206) and the low-pressure reheater (207).

2. The liquid air energy storage system based on the retrofitting of decommissioned coal-fired power units according to claim 1, characterized in that: The gas-side outlet of the first compressor (102) is connected to the gas-side input of the first low-pressure cooler (203), the gas-side output of the first low-pressure cooler (203) is connected to the gas-side input of the second compressor (104), the gas-side outlet of the second compressor (104) is connected to the gas-side input of the second high-pressure cooler (204), the gas-side output of the second high-pressure cooler (204) is connected to the input of the liquefaction main heat exchanger (105), the output of the liquefaction main heat exchanger (105) is connected to the input of the liquid storage tank (107), and the liquefaction main heat exchanger (105) is connected to the cold release end of the cold storage device (106).

3. The liquid air energy storage system based on the retrofitting of decommissioned coal-fired power units according to claim 1, characterized in that: The output end of the low-temperature water storage device (201) is connected to the water-side input end of the first low-pressure cooler (203) and the second high-pressure cooler (204), respectively. The water-side output end of the first low-pressure cooler (203) and the second high-pressure cooler (204) is connected to the input end of the high-temperature heat storage device (205), respectively.

4. The liquid air energy storage system based on the retrofitting of decommissioned coal-fired power units according to claim 1, characterized in that: The outlet of the low-temperature water storage device (201) is equipped with a hot water pump (202).

5. The liquid air energy storage system based on the retrofitting of decommissioned coal-fired power units according to claim 1, characterized in that: The air expander (208) is a multi-stage air expander; the output end of the evaporator (109) is connected to the gas-side input end of the high-pressure reheater (206), and the gas-side output end of the high-pressure reheater (206) is connected to the input end of the air expander (208); the interstage exhaust outlet of the air expander (208) is connected to the gas-side input end of the low-pressure reheater (207), and the gas-side output end of the low-pressure reheater (207) is connected to the input end of the air expander (208) below the interstage exhaust outlet connected to the gas-side input end of the low-pressure reheater (207).

6. The liquid air energy storage system based on the retrofitting of decommissioned coal-fired power units according to claim 1, characterized in that: A pressure pump (108) is also provided at the liquid air outlet of the storage tank (107).

7. The liquid air energy storage system based on the retrofitting of decommissioned coal-fired power units according to claim 1, characterized in that: The cold storage end of the cold storage device (106) is connected to the evaporator (109).

8. The liquid air energy storage system based on the retrofitting of decommissioned coal-fired power units according to claim 1, characterized in that: The newly added equipment unit (100) also includes a first compressor motor (101) connected to the first compressor (102) and a second compressor motor (103) connected to the second compressor (104). A first energy storage circuit breaker (110) for controlling the first compressor (102) is provided on the power input line of the first compressor motor (101), and a second energy storage circuit breaker (111) for controlling the second compressor (104) is provided on the power input line of the second compressor motor (103). The first energy storage circuit breaker (110) and the second energy storage circuit breaker (111) are connected in parallel and then connected to the energy storage transformer (112). The energy storage transformer (112) is connected to the outlet of the generator (209).

9. The liquid air energy storage system based on the retrofitting of decommissioned coal-fired power units according to claim 8, characterized in that: The coal-fired power unit equipment reuse unit (200) also includes an energy release circuit breaker (210), a high-voltage plant transformer (211), a plant power bus (213), a booster station (214), and a coal-fired power unit high-voltage bus (215). The energy release circuit breaker (210) is located at the outlet of the generator (209). The outlet of the generator (209) is connected to the high-voltage plant transformer (211) and the booster station (214) respectively. The high-voltage plant transformer (211) and the booster station (214) are connected in parallel with the energy storage transformer (112) respectively.

10. The liquid air energy storage system based on the retrofitting of decommissioned coal-fired power units according to claim 9, characterized in that: The high-voltage plant transformer (211) is connected to the plant power bus (213), and the plant power bus (213) is equipped with a plant power circuit breaker (212).

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