Liquefied air energy storage system coupled with LNG (Liquefied Natural Gas) cold energy and control method thereof

Abstract

The invention relates to a liquid air energy storage system coupled with LNG cold energy and a control method. The system comprises an LNG gasification subsystem, a compressed air liquefaction subsystem, a gasification liquid air expansion power generation subsystem and a waste heat recovery circulation subsystem. LNG and liquid air gasification cold energy are stored, recycled and applied to the liquefied air energy storage system through the regenerator, the problem that the energy storage efficiency is not high due to the fact that the cold energy of the liquefied air energy storage system is insufficient is solved, in addition, the liquid air energy storage system coupled with LNG cold energy is dynamically controlled through the control method, and the energy storage efficiency is improved. And the influence of cold energy fluctuation of the regenerator on the liquefaction performance of the system is reduced. According to the system, LNG cold energy is utilized in a gradient mode, the air liquefaction power is improved, and the stability of the liquefaction performance of the liquefied air energy storage system is further improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of liquefied air energy storage, and in particular relates to a liquid air energy storage system coupled with LNG cold energy and a control method thereof. Background Art

[0002] With the increase in electricity demand and the promotion and utilization of renewable energy, the importance of peak load power will become increasingly prominent. Liquid air energy storage technology can store and regulate electrical energy and convert it back into electrical energy when needed. It has the advantages of high energy density, small footprint, and low unit energy storage capacity cost. It can be flexibly applied to the power generation side, transmission and distribution side, and user side. It is a medium-duration, large-capacity energy storage technology.

[0003] However, due to the limited available cold energy in the air liquefaction process, the energy conversion efficiency of the current independent liquid air energy storage system is relatively low, only 50~55%. The most common solution to this is to couple an external cold source, such as combining LNG cold energy, and using the cold energy released during the LNG gasification process to liquefy the high-pressure air. The existing patent CN 202311705622.X proposes a cold and heat integrated liquid air energy storage system, which uses the cold energy of LNG to cool the working fluid and improve the energy utilization of the system. However, this type of system has problems such as inappropriate cold energy allocation when applied. For example, during the discharge and shutdown stages of the liquid air energy storage system, the LNG cold energy in the coupling system cannot be fully utilized, resulting in cold energy waste.

[0004] In order to better couple LNG cold energy, the cold energy released during the energy release phase of liquid air is usually recovered by adding cold storage units. For example, the liquid air energy storage system uses a cold storage device to recover LNG cold energy. For example, the existing patent CN 118463500 A proposes a liquid air energy storage system and method coupled with LNG cold energy. At an appropriate time, the cold energy in the cold storage device is used to cool the liquid air energy storage system. However, the performance of the liquid air energy storage system after adding the cold storage unit will be affected by the fluctuation of the cold energy in the cold storage unit, because as the operating time increases, the cold energy in the cold storage unit gradually decreases. If a constant heat transfer medium flow rate is used, the liquefaction rate of the liquid air energy storage system in the energy storage phase will be greatly reduced due to insufficient cold energy. However, few studies have proposed dynamic control methods to adjust the problem of insufficient cold energy. Therefore, it is particularly important to enhance the flexibility, adaptability, and stability of the liquid air energy storage system coupled with an external cold source. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a liquid air energy storage system coupled with LNG cold energy and a control method thereof in view of the deficiencies of the above-mentioned prior art, so as to enhance the flexibility, adaptability and stability of the system.

[0006] In order to achieve the above technical objectives, the technical solution adopted by the present invention is: A liquid air energy storage system coupled with LNG cold energy, comprising an LNG gasification subsystem, a compressed air liquefaction subsystem, a gasified liquid air expansion power generation subsystem and a waste heat recovery circulation subsystem; The LNG gasification subsystem includes a No. 1 cryogenic pump, a separator, a No. 1 valve and a vaporizer connected in sequence, and a No. 1 packed bed refrigerant connected to the vaporizer via a No. 1 four-way valve and a No. 2 four-way valve at both ends respectively; The compressed air liquefaction subsystem includes a No. 3 valve, a No. 1 compressor, a No. 1 heat exchanger, a No. 2 compressor, a No. 2 heat exchanger, a No. 3 compressor, a No. 3 heat exchanger, a cold box, a temperature controller, a pressure reducing valve and a liquid air storage tank, as well as a No. 1 flow controller, a No. 2 flow controller, a No. 2 cold storage filling bed, a No. 2 valve, a heater, a No. 3 four-way valve, a No. 4 four-way valve and a No. 3 flow controller, which are connected in sequence; The two ends of the cold box are connected to the first cold storage filling bed through a first four-way valve and a second four-way valve, respectively, and a second flow controller is provided in the connecting pipe between the second four-way valve and the cold box; Both ends of the cold box are also connected to the No. 2 valve and the heater, and a No. 1 flow controller is provided in the pipeline connecting the No. 2 valve and the cold box; The two ends of the No. 2 cold storage filling bed are connected to the cold box through the No. 3 four-way valve and the No. 4 four-way valve respectively, and a No. 3 flow controller is provided in the connecting pipe between the No. 3 four-way valve and the cold box; The gasified liquid air expansion and generation subsystem includes a No. 4 valve, a No. 2 cryogenic pump, an evaporator, a No. 4 heat exchanger, a No. 1 expander, a No. 5 heat exchanger, a No. 2 expander, a No. 6 heat exchanger and a No. 3 expander connected in sequence; The hot side of the evaporator is connected to the No. 2 cold storage packed bed through the No. 3 four-way valve and the No. 4 four-way valve; The waste heat recovery subsystem includes a cold oil tank, a No. 1 solution pump, a hot oil tank, and a No. 2 solution pump. The cold oil tank is connected to the No. 1 solution pump, the No. 1 heat exchanger, the No. 2 heat exchanger, the No. 3 heat exchanger, the No. 4 heat exchanger, the No. 5 heat exchanger, and the No. 6 heat exchanger in sequence.

[0007] To optimize the above technical solutions, the specific measures taken also include: The output end of the No. 1 cryogenic pump in the above-mentioned LNG gasification subsystem is connected to the input end of the separator, the first output end of the separator is connected to the input end of the No. 1 valve, the output end of the No. 1 valve is connected to the cold side input end of the vaporizer, the first output end of the No. 1 four-way valve is connected to the hot side input end of the vaporizer, the first input end of the No. 2 four-way valve is connected to the hot side output end of the vaporizer, the second output end of the No. 1 four-way valve is connected to the input end of the No. 1 packed bed cold accumulator, and the first output end of the No. 2 four-way valve is connected to the output end of the No. 1 packed bed cold accumulator.

[0008] The output end of valve No. 3 in the compressed air liquefaction subsystem is connected to the input end of compressor No. 1, the output end of compressor No. 1 is connected to the hot side input end of heat exchanger No. 1, the hot side output end of heat exchanger No. 1 is connected to the input end of compressor No. 2, the output end of compressor No. 2 is connected to the hot side input end of heat exchanger No. 2, the hot side output end of heat exchanger No. 2 is connected to the input end of compressor No. 3, the output end of compressor No. 3 is connected to the hot side input end of heat exchanger No. 3, the hot side output end of heat exchanger No. 3 is connected to the third input end of cold box, and the third output end of cold box is connected to the input end of pressure reducing valve. The output end of the pressure reducing valve is connected to the input end of the liquid air storage tank, the gas output end of the liquid air storage tank is connected to the fourth input end of the cold box, the first input end of the cold box is connected to the output end of the No. 2 four-way valve, the first output end of the cold box is connected to the second input end of the No. 1 four-way valve, the first output end of the No. 3 four-way valve is connected to the fifth input end, the fifth output end of the cold box is connected to the input end of the No. 4 four-way valve, the inlet of the No. 2 valve is connected to the second output end of the separator, the output end of the No. 2 valve is connected to the third input end of the cold box, and the third input end of the cold box is connected to the cold side output end of the heater.

[0009] The output end of valve No. 4 in the above-mentioned gasified liquid air expansion and power generation subsystem is connected to the input end of cryogenic pump No. 2, the output end of cryogenic pump No. 2 is connected to the cold side input end of evaporator, the cold side input end of heat exchanger No. 4 is connected to the cold side output end of evaporator, the cold side output end of heat exchanger No. 4 is connected to the input end of expander No. 1, the output end of expander No. 1 is connected to the cold side input end of heat exchanger No. 5, the cold side output end of heat exchanger No. 5 is connected to the input end of expander No. 2, the output end of expander No. 2 is connected to the cold side input end of heat exchanger No. 6, the cold side output end of heat exchanger No. 6 is connected to the input end of expander No. 3, the output end of expander No. 3 is connected to the outside world, the hot side input end of evaporator is connected to the output end of four-way valve No. 4, the hot side output end of evaporator is connected to the second input end of four-way valve No. 3, the second output end of four-way valve No. 3 is connected to the input end of cold storage filling bed No. 2, the first input end of four-way valve No. 4 is connected to the output end of cold storage filling bed No. 2.

[0010] In the above-mentioned waste heat recovery subsystem, the output end of the No. 1 solution pump is connected to the cold side input end of the No. 1 heat exchanger, the cold side input end of the No. 2 heat exchanger, and the cold side input end of the No. 3 heat exchanger in sequence, the input end of the hot oil tank is connected to the cold side output end of the No. 1 heat exchanger, the cold side output end of the No. 2 heat exchanger, and the cold side output end of the No. 3 heat exchanger in sequence, the output end of the hot oil tank is connected to the input end of the No. 2 solution pump, the output end of the No. 2 solution pump is connected to the hot side input end of the No. 4 heat exchanger, the hot side input end of the No. 5 heat exchanger, and the hot side input end of the No. 6 heat exchanger in sequence, the input end of the cold oil tank is connected to the hot side output end of the No. 4 heat exchanger, the hot side output end of the No. 5 heat exchanger, and the hot side output end of the No. 6 heat exchanger in sequence, and the output end of the cold oil tank is connected to the input end of the No. 1 solution pump.

[0011] The No. 1 valve and the No. 2 valve are connected to the first and second output ends of the separator. The No. 1 valve and the No. 2 valve are cut-off valves, and the flow rate of the working medium can be adjusted by adjusting the valve opening. The No. 1 four-way valve is respectively connected to the hot side output end of the gasifier, the input end of the No. 1 cold storage filling bed and the first output end of the cold box. The first input end of the No. 1 four-way valve is connected to the outside world and is closed and opened according to the operation requirements. When opened, the heat transfer medium is supplemented. The No. 2 four-way valve is respectively connected to the cold side output end of the gasifier, the No. 1 cold storage filled bed output end and the first input end of the cold box. The second input end of the No. 2 four-way valve can be closed and opened according to the operation requirements, and the heat transfer medium can be released when it is opened; The No. 3 four-way valve is respectively connected to the hot side output end of the evaporator, the input end of the No. 2 cold storage filling bed and the fifth input end of the cold box. The first input end of the No. 3 four-way valve is connected to the outside world and can be closed and opened according to the operation requirements. When opened, the heat transfer medium can be supplemented; The second output end of the No. 4 four-way valve is respectively connected to the hot side input end of the evaporator, the output end of the No. 2 cold storage filling bed and the fifth output end of the cold box. The second input end of the No. 4 four-way valve can be closed and opened according to the operating requirements, and the heat transfer medium can be released when opened.

[0012] A control method for a liquid air energy storage system coupled with LNG cold energy, in energy storage mode control, first, open valve No. 3, close valve No. 1 and valve No. 4, open valve No. 2, open the first input end, the second input end, and the second output end of the No. 1 four-way valve, close the first output end of the No. 1 four-way valve, open the second input end, the first output end, and the second output end of the No. 2 four-way valve, close the first input end of the No. 2 four-way valve, open the first input end, the first output end, and the second output end of the No. 3 four-way valve, close the second input end of the No. 3 four-way valve, open the first input end, the first output end, and the second input end of the No. 4 four-way valve, and close the second output end of the No. 4 four-way valve; At this time, the cold storage filling bed No. 1 and the cold storage filling bed No. 2 already store the cold energy released by the gasification of liquid natural gas and liquid air; the working air flows through the No. 3 valve, the No. 1 compressor, the No. 2 compressor and the No. 3 compressor in turn, after being pressurized and heated, enters the No. 1 heat exchanger, the No. 2 heat exchanger and the No. 3 heat exchanger to cool down to room temperature, and then enters the cold box for further cooling, the low-temperature working air flows out from the third output end of the cold box, enters the pressure reducing valve for throttling and pressure reduction, and is converted into a gas-liquid two-phase state, and then enters the liquid air tank, the low-temperature gaseous working air flows out from the gas output end of the liquid air tank, flows into the cold box from the fourth input end of the cold box for cooling, and then flows out from the fourth output end of the cold box; at the same time, the room-temperature heat transfer oil in the cold oil tank is sucked by the solution pump, and is sent to the No. 1 heat exchanger, the No. 2 heat exchanger and the No. 3 heat exchanger in turn to cool the high-temperature working air; In the energy storage mode, the cold in the No. 1 cold storage filled bed cools the heat transfer medium, and the low-temperature heat transfer medium enters the cold box through the second output end of the No. 2 four-way valve to cool the working air, and the heat transfer medium after heat exchange enters the No. 1 cold storage filled bed through the No. 1 four-way valve; the cold in the No. 2 cold storage filled bed cools the heat transfer medium, and the low-temperature heat transfer medium enters the cold box through the first output end of the No. 4 four-way valve to cool the working air, and the heat transfer medium after heat exchange enters the No. 2 cold storage filled bed through the No. 3 four-way valve, and the cycle is in sequence; as the energy storage time continues to increase, the cold in the No. 1 cold storage filled bed and the No. 2 cold storage filled bed continues to decrease. At this time, liquid natural gas enters the cold box through the No. 2 valve to supplement the system with cold, ensuring that the system liquefaction rate remains stable.

[0013] The above control method, when in energy release mode control, first, close valve No. 3 and valve No. 2, open valve No. 1 and valve No. 4, close the first input end and the second input end of the No. 1 four-way valve, open the first output end and the second output end of the No. 1 four-way valve, open the first output end and the first input end of the No. 2 four-way valve, close the second input end and the second output end of the No. 2 four-way valve, open the first output end and the second output end of the No. 3 four-way valve, close the first input end and the second input end of the No. 3 four-way valve, open the first input end and the first output end of the No. 4 four-way valve, and close the second input end and the second output end of the No. 4 four-way valve; Liquid air is sucked from the output end of the liquid air storage tank by the No. 3 solution pump and sent to the evaporator for gasification. The gaseous working air enters the No. 4 heat exchanger, the No. 5 heat exchanger, and the No. 6 heat exchanger in turn for heating and temperature rise, and then enters the No. 1 expander, the No. 2 expander, and the No. 3 expander in turn for expansion and power generation. The high-temperature heat transfer oil in the hot oil tank is sucked by the No. 2 solution pump and sent to the No. 4 heat exchanger, the No. 5 heat exchanger, and the No. 6 heat exchanger in turn for heating, and then merges and flows into the cold oil tank for storage. The heat transfer medium in the No. 2 cold storage filling bed enters the evaporator through the second output end of the No. 4 four-way valve to heat the liquid working air. The cooled heat transfer medium enters the No. 2 cold storage filling bed through the No. 3 four-way valve to store cold. At the same time, liquid natural gas is sucked by the No. 1 low-temperature pump and sent to the separator. It enters the vaporizer through the No. 1 valve to exchange heat with the heat transfer medium. The low-temperature heat transfer medium enters the No. 1 cold storage filling bed through the No. 2 four-way valve to store cold.

[0014] The above control method, when in shutdown mode control, closes valve No. 2, valve No. 3, valve No. 4, four-way valve No. 3, and four-way valve No. 4, closes the first input end and the second input end of the four-way valve No. 1, opens the first output end and the second output end of the four-way valve No. 1, opens the second input end and the first input end of the four-way valve No. 2, and closes the second output end and the first output end of the four-way valve No. 2; Liquid natural gas is sucked by the No. 1 cryogenic pump and sent into the separator, then enters the vaporizer through the No. 1 valve to exchange heat with the heat transfer medium. The low-temperature heat transfer medium enters the No. 1 cold storage filling bed through the No. 2 four-way valve to store the cold.

[0015] In the above control method, in the energy storage mode, valve No. 2, four-way valve No. 1, four-way valve No. 2, four-way valve No. 3, and four-way valve No. 4 are opened, and the valve openings of valve No. 2, four-way valve No. 1, four-way valve No. 2, four-way valve No. 3, and four-way valve No. 4 are controlled by adjusting flow controller No. 1, flow controller No. 2, and flow controller No. 3, so that the temperature of the third output end of the cold box remains consistent and is not affected by the reduction in the cooling capacity of the cold storage filling bed; The temperature of the third output end of the cold box is continuously increased due to the influence of the No. 1 cold storage filled bed and the No. 2 cold storage filled bed. By adjusting the opening of the No. 2 valve, the No. 1 four-way valve and the No. 3 four-way valve, the flow rate of liquid natural gas and heat transfer medium is increased, thereby increasing the cooling capacity in the liquid air energy storage system with cold storage filled beds, so that the temperature of the third output end of the cold box can be kept consistent.

[0016] The present invention has the following beneficial effects: The present invention utilizes the No. 1 cold storage filled bed to recover and store the external cold source coupled to the liquid air energy storage system during the energy release stage and the shutdown stage, such as the gasification cold of LNG, to ensure the normal operation of the LNG gasification process. The No. 2 cold storage filled bed is utilized to recover the cold energy generated when the liquid air is gasified, and cooperates with the No. 1 cold storage filled bed to release the cold energy during the energy storage stage of the liquid air energy storage system, so as to improve the air liquefaction rate of the liquid air energy storage system and increase the power generation of the system. Through the control method proposed in the present invention, the flow rate of liquefied natural gas and heat transfer medium is dynamically regulated to stabilize the liquefaction performance of the liquid air energy storage system, so as to achieve the working air temperature at the output end of the cold box to remain consistent and not be affected by the reduction of the cold energy of the cold storage filled bed.

[0017] A liquid air energy storage system coupled with LNG cold energy and a control method thereof can overcome the problem of continuous gasification of LNG; the influence of cold capacity fluctuation in the cold storage packed bed on the liquefaction performance of the liquid air energy storage system is alleviated by dynamic adjustment; in addition, the problem of residual cold capacity of the cold storage packed bed during the circulation use process is alleviated by increasing the flow rate of heat transfer medium in the cold storage packed bed; the cold capacity of liquefied air is increased by increasing the LNG gasification flow rate, making the liquefied air more sufficient.

[0018] The invention relates to a liquid air energy storage system coupled with LNG cold energy and a control method. It includes an LNG gasification subsystem, a compressed air liquefaction subsystem, a gasified liquid air expansion power generation subsystem, and a waste heat recovery circulation subsystem. The cold energy of LNG and liquid air gasification is stored, recovered and applied to the liquefied air energy storage system by using a cold storage device, which alleviates the problem of low energy storage efficiency caused by insufficient cold energy of the liquefied air energy storage system. In addition, the liquid air energy storage system coupled with LNG cold energy is dynamically controlled by a control method to reduce the impact of cold energy fluctuations of the cold storage device on the liquefaction performance of the system. The system not only utilizes LNG cold energy in a cascade manner and improves the air liquefaction power, but also further improves the stability of the liquefaction performance of the liquefied air energy storage system. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural diagram of a liquid air energy storage system coupled with LNG cold energy.

[0020] Figure 2 It is the structural diagram of the compressed air liquefaction subsystem.

[0021] Figure 3 It is a structural diagram of the liquefied air expansion and generation subsystem.

[0022] Figure 4 It is the structural diagram of the waste heat recovery subsystem.

[0023] Figure 5 It is a structural diagram of the LNG gasification subsystem.

[0024] The reference numerals are: 1- compressor No. 1, 1a- compressor No. 1 input end, 1b- compressor No. 1 input end, 2- heat exchanger No. 1, 2a- heat side input end of heat exchanger No. 1, 2b-hot side output end of heat exchanger No. 1, 2c-cold side input end of heat exchanger No. 1, 2d-cold side output end of heat exchanger No. 1, 3-compressor No. 2, 3a-compressor No. 2 input end, 3b-compressor No. 2 input end, 4-heat exchanger No. 2, 4a-hot side input end of heat exchanger No. 2, 4b-hot side output end of heat exchanger No. 2, 4c-cold side input end of heat exchanger No. 2, 4d-cold side output end of heat exchanger No. 2, 5-compressor No. 3, 5a-compressor No. 2 input end, 5b-compressor No. 2 input end, 6-heat exchanger No. 3, 6a-hot side input end of heat exchanger No. 3, 6b-hot side output end of heat exchanger No. 3, 6c-cold side input end of heat exchanger No. 3, 6d-cold side output end of heat exchanger No. 3, 7-cold box, 7a-first input end of cold box, 7b-first output end of cold box, 7c-second input end of cold box, 7d-second output end of cold box, 7e-third input end of cold box, 7f-third output end of cold box, 7g-fourth input end of cold box, 7h-fourth output end of cold box, 7i-fifth input end of cold box, 7j-fifth output end of cold box, 8-pressure reducing valve, 8a-pressure reducing valve input end, 8b-pressure reducing valve input end, 9-liquid air storage tank, 9a-liquid air storage tank input end, 9b-first gas output end of liquid air storage tank, 9c-second liquid output end of liquid air storage tank, 10-No. 2 cryogenic pump, 10a-No. 2 cryogenic pump input end, 10b-No. 2 cryogenic pump input end, 11 -gasifier, 11a-hot side input end of gasifier, 11b-hot side output end of gasifier, 11c-cold side input end of gasifier, 11d-cold side output end of gasifier, 12-No. 4 heat exchanger, 12a-hot side input end of No. 4 heat exchanger, 12b-hot side output end of No. 4 heat exchanger, 12c-cold side input end of No. 4 heat exchanger, 12d-cold side output end of No. 4 heat exchanger, 13-No. 1 expander, 13a-No. 1 expander input end, 13b-No. 1 expander output end, 14-No. 5 heat exchanger, 14a-hot side input end of No. 5 heat exchanger, 14b-hot side output end of No. 5 heat exchanger, 14c-cold side input end of No. 5 heat exchanger, 14d-cold side output end of No. 5 heat exchanger, 15-No. 2 No. 6 expander, 15a-No. 2 expander input end, 15b-No. 2 expander output end, 16-No. 6 heat exchanger, 16a-No. 6 heat exchanger hot side input end, 16b-No. 6 heat exchanger hot side output end, 16c-No. 6 heat exchanger cold side input end, 16d-No. 6 heat exchanger cold side output end, 17-No. 3 expander, 17a-No. 3 expander input end, 17b-No. 3 expander output end, 18-No. 2 solution pump, 18a-No. 2 solution pump input end, 18b-No. 2 solution pump output end, 19-hot oil tank, 19a-hot oil tank input end, 19b-hot oil tank output end, 20-No. 1 solution pump, 20a-No. 1 solution pump input end, 20b-No. 1 solution pump output end,21-cold oil tank, 21a-cold oil tank input, 21b-cold oil tank output, 22-No. 2 cold storage filled bed, 22a-No. 2 cold storage filled bed input, 22b-No. 2 cold storage filled bed output, 23-No. 1 cryogenic pump, 23a-No. 1 cryogenic pump input, 23b-No. 1 cryogenic pump output, 24-separator, 24a-separator input, 24b-separator first output, 24c-separator second output, 25-No. 2 valve, 25a-No. 2 valve input, 25b-No. 2 valve output, 26-No. 1 valve, 26a- No. 1 valve input, 26b- No. 1 valve output, 27- gasifier, 27a- gasifier hot side input, 27b- gasifier hot side output, 27c- gasifier cold side input, 27d- gasifier cold side output, 28- No. 1 cold storage filled bed, 28a- No. 1 cold storage filled bed input, 28b- No. 1 cold storage filled bed output, 29- heater, 29a- heater hot side input, 29b- heater hot side output, 29c- heater cold side input, 29d- heater cold side output, 30- No. 1 four-way valve, 30a- 30a-first input end of No. 1 four-way valve, 30b-first output end of No. 1 four-way valve, 30c-second input end of No. 1 four-way valve, 30d-second output end of No. 1 four-way valve, 31-No. 2 four-way valve, 31a-first input end of No. 2 four-way valve, 31b-first output end of No. 2 four-way valve, 31c-second input end of No. 2 four-way valve, 31d-second output end of No. 2 four-way valve, 32-No. 3 four-way valve, 32a-first input end of No. 3 four-way valve, 32b-first output end of No. 3 four-way valve, 32c-second input end of No. 3 four-way valve, 32d - second output end of No. 3 four-way valve, 33- No. 4 four-way valve, 33a- first input end of No. 4 four-way valve, 33b- first output end of No. 4 four-way valve, 33c- second input end of No. 4 four-way valve, 33d- second output end of No. 4 four-way valve, 34- No. 3 valve, 34a- input end of No. 3 valve, 34b- output end of No. 3 valve, 35- No. 4 valve, 35a- input end of No. 4 valve, 35b- output end of No. 4 valve, 101- No. 1 flow controller, 102- No. 2 flow, 103- temperature controller, 104- No. 3 flow controller. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0026] Although the steps in the present invention are arranged with numbers, they are not used to limit the order of the steps. Unless the order of the steps is clearly stated or the execution of a certain step requires other steps as a basis, the relative order of the steps can be adjusted. It is understood that the term "and / or" used in this article involves and covers any and all possible combinations of one or more of the associated listed items.

[0027] like Figure 1 As shown, a liquid air energy storage system coupled with LNG cold energy in an embodiment of the present invention can realize aircraft environment control by supplying hot water through air circulation. The system mainly comprises a No. 1 compressor 1, a No. 1 heat exchanger 2, a No. 2 compressor 3, a No. 2 heat exchanger 4, a No. 3 compressor 5, a No. 3 heat exchanger 6, a cold box 7, a pressure reducing valve 8, a liquid air storage tank 9, a No. 2 cryogenic pump 10, a vaporizer 11, a No. 4 heat exchanger 12, a No. 1 expander 13, a No. 5 heat exchanger 14, a No. 2 expander 15, a No. 6 heat exchanger 16, a No. 3 expander 17, a No. 2 The invention consists of a solution pump No. 18, a hot oil tank 19, a solution pump No. 1 20, a cold oil tank 21, a cold storage filled bed No. 2 22, a low-temperature pump No. 1 23, a separator 24, a valve No. 2 25, a valve No. 1 26, a vaporizer 27, a cold storage filled bed No. 1 28, a heater 29, a four-way valve No. 1 30, a four-way valve No. 2 31, a four-way valve No. 3 32, a four-way valve No. 4 33, a valve No. 3 34, a valve No. 4 35, a flow controller No. 1 101, a flow controller No. 2 102, a temperature controller 103, and a flow controller No. 3 104.

[0028] Preferably, the separator 24 includes an input end, a first output end and a second output end; valve No. 1 26 includes an input end and an output end; valve No. 25 includes an input end and an output end; the first output end of the separator 24 is connected to the input end of valve No. 1 26, and the second output end of the separator 24 is connected to the input end of valve No. 2 25.

[0029] The cold box 7 includes a first input end, a first output end, a second input end, a second output end, a third input end, a third output end, a fourth input end, a fourth output end, a fifth input end, and a fifth output end; the third heat exchanger 6 includes a hot side input end, a hot side output end, a cold side input end, and a cold side output end; the pressure reducing valve 8 includes an input end and an output end; the first four-way valve 30 includes a first input end, a first output end, a second input end, and a second output end; The No. 2 four-way valve 31 includes a first input end, a first output end, a second input end, and a second output end; the No. 3 four-way valve 32 includes a first input end, a first output end, a second input end, and a second output end; the No. 4 four-way valve 33 includes a first input end, a first output end, a second input end, and a second output end; the first input end of the cold box 7 is connected to the second output end of the No. 2 four-way valve 31, the first output end of the cold box 7 is connected to the second input end of the No. 1 four-way valve, the second input end of the cold box 7 is connected to the No. 2 valve input end, the second output end of the cold box 7 is connected to the cold side input end of the heater, the third input end of the cold box is connected to the hot side output end of the No. 3 heat exchanger, the third output end of the cold box 7 is connected to the pressure reducing valve input end, the fourth input end of the cold box 7 is connected to the gas output end of the liquid air storage tank, the fourth output end of the cold box 7 is connected to the outside world, the fifth input end of the cold box is connected to the first output end of the No. 3 four-way valve 32, and the fifth output end of the cold box 7 is connected to the first input end of the No. 4 four-way valve 33.

[0030] The vaporizer 27 includes a hot side input end, a hot side output end, a cold side input end, and a cold side output end; the first cold storage filled bed includes an input end and an output end; the second cold storage filled bed 22 includes an input end and an output end; the first input end of the first four-way valve 30 is connected to the outside, the first output end of the first four-way valve 30 is connected to the hot side input end of the vaporizer 27, the second output end of the first four-way valve 30 is connected to the input end of the first cold storage filled bed 22; the second output end of the second four-way valve 31 is connected to the outside The second input end of the No. 2 four-way valve 31 is connected to the hot side output end of the No. 1 cold storage filled bed 28; the first input end of the No. 3 four-way valve is connected to the outside world, the second input end of the No. 3 four-way valve is connected to the hot side input end of the evaporator, and the second output end of the No. 3 four-way valve is connected to the input end of the No. 2 cold storage filled bed; the first output end of the No. 4 four-way valve is connected to the outside world, the second input end of the No. 4 four-way valve is connected to the output end of the No. 2 cold storage filled bed, and the second output end of the No. 4 four-way valve is connected to the hot side input end of the evaporator.

[0031] The cold storage capacity of the packing in the first cold storage packed bed 28 and the second cold storage packed bed 22 is greater than the cold released by the liquid natural gas and liquid air in the gasifier 27 and the evaporator 11 to ensure full absorption of the cold in the system.

[0032] The filling medium in the low-temperature cold storage device can be a sensible heat storage material, such as goose warm stone, quartz stone, calcium carbonate, steel balls, etc. It is also possible to choose to use new composite materials such as phase change materials and phase change microcapsules.

[0033] The waste heat recovery medium in the system can be water, heat transfer oil and other media. The heat transfer medium can be: air, nitrogen, carbon dioxide, propane, etc.

[0034] The system includes LNG gasification subsystem, compressed air liquefaction subsystem, gasified liquid air expansion and power generation subsystem and waste heat recovery circulation subsystem; The circulating medium in the waste heat recovery circulation subsystem can be water, heat transfer oil and other media, and the heat transfer medium can be: air, nitrogen, carbon dioxide, propane, etc. The filling medium in the low-temperature cold storage device can be a sensible heat storage material, such as goose warm stone, quartz stone, calcium carbonate, steel balls, etc. It is also possible to choose to use new composite materials such as phase change materials and phase change microcapsules. In order to illustrate the specific implementation scheme of the present invention, in the following description, the circulating medium can be water, the heat transfer medium can be air, and the filling medium in the low-temperature cold storage device can be goose warm stone as an example.

[0035] LNG gasification subsystem: The LNG gasification subsystem includes: a No. 1 cryogenic pump 23, a separator 24, a No. 1 valve 26, a vaporizer 27, a No. 1 packed bed refrigerant 28, a No. 1 four-way valve 30, and a No. 2 four-way valve 31. The No. 1 cryogenic pump 23, the separator 24, the No. 1 valve 26, and the vaporizer 27 are connected in sequence, and the No. 1 four-way valve 30, the vaporizer 27, the No. 1 packed bed refrigerant 28, and the No. 2 four-way valve 31 are connected in sequence.

[0036] The low-temperature pump output end 23b of the LNG gasification subsystem is connected to the separator input end (24a), the first output end of the separator is connected to the No. 1 valve input end (26a), the No. 1 valve output end (26b) is connected to the cold side input end (27c) of the vaporizer, the hot side output end 27d of the vaporizer is connected to the No. 2 four-way valve input end 31a, the No. 1 four-way valve first output end 30b is connected to the hot side input end 27a of the vaporizer, the No. 2 four-way valve first input end 31a is connected to the hot side output end 27b of the vaporizer, the No. 1 four-way valve second output end 30d is connected to the No. 1 cold storage filled bed input end 28a, and the No. 2 four-way valve first output end 31b is connected to the No. 1 cold storage filled bed output end 28b.

[0037] Compressed air liquefaction subsystem: The compressed air liquefaction subsystem includes: valve No. 3 34, compressor No. 1 1, heat exchanger No. 1 2, compressor No. 2 3, heat exchanger No. 2 4, compressor No. 3 5, heat exchanger No. 3 6, cold box 7, temperature controller 103, pressure reducing valve 8, liquid air storage tank 9, four-way valve No. 1 30, four-way valve No. 2 31, four-way valve No. 3 32, four-way valve No. 4 33, flow controller No. 3 104, cold storage filled bed No. 2 22, valve No. 2 25, flow controller No. 1 101, heater 29, cold storage filled bed No. 1 28. The No. 3 valve 34, the No. 1 compressor 1, the No. 1 heat exchanger 2, the No. 2 compressor 3, the No. 2 heat exchanger 4, the No. 3 compressor 5, the No. 3 heat exchanger 6, the cold box 7, the temperature controller 103, the pressure reducing valve 8, and the liquid air storage tank 9 are connected in sequence; the No. 1 four-way valve 30, the cold box 7, the No. 2 four-way valve 31 are connected to the No. 1 cold storage filled bed 28, wherein the No. 2 four-way valve 31 is connected to the cold box 7 connecting pipeline and the No. 2 flow controller 102 is added; the No. 2 valve 25, the cold box 7, and the heater 29 are connected in sequence, and the No. 1 flow controller 101 is added to the No. 2 valve 25 connecting pipeline and the cold box 7; the No. 3 four-way valve 32, the cold box 7, the No. 4 four-way valve 33 are connected to the No. 2 cold storage filled bed 22, wherein the No. 3 four-way valve 32 is connected to the cold box 7 connecting pipeline and the No. 3 flow controller 104 is added.

[0038] The output terminal 34b of the No. 3 valve in the compressed air liquefaction subsystem is connected to the input terminal 1a of the No. 1 compressor, the output terminal 1b of the No. 1 compressor is connected to the hot side input terminal 2a of the No. 1 heat exchanger, the hot side output terminal 2b of the No. 1 heat exchanger is connected to the input terminal 3a of the No. 2 compressor, the output terminal 3b of the No. 2 compressor is connected to the hot side input terminal 4a of the No. 2 heat exchanger, the hot side output terminal 4b of the No. 2 heat exchanger is connected to the input terminal 5a of the No. 3 compressor, the output terminal 5b of the No. 3 compressor is connected to the hot side input terminal 6a of the No. 3 heat exchanger, the hot side output terminal 6b of the No. 3 heat exchanger is connected to the third input terminal 7e of the cold box, and the output terminal 7f of the cold box is connected to the output terminal of the pressure reducing valve. The input end 8a is connected, wherein a temperature controller 103 is arranged, the pressure reducing valve output end 8b is connected to the liquid air storage tank input end 9a, the liquid air storage tank gas first output end 9b is connected to the fourth input end 7g of the cold box, the first input end 7a of the cold box is connected to the No. 2 four-way valve output end 31b, wherein a No. 2 flow controller 102 is arranged, the first output end 7b of the cold box is connected to the No. 1 four-way valve input end 30c, the No. 3 four-way valve output end 32a is connected to the fifth input end 7i of the cold box, the fifth output end 7j of the cold box is connected to the No. 3 four-way valve input end 32a, wherein a No. 3 flow controller 104 is arranged.

[0039] The air sucked from the environment first enters the No. 1 compressor 1 for pressurization, and then is sent to the No. 1 heat exchanger 2 for cooling. When the temperature meets the requirements, it is sent to the No. 2 compressor 3 for re-pressurization, and then enters the No. 2 heat exchanger 4 for cooling again, and then enters the No. 3 compressor 5 for pressurization to the liquefaction pressure. The air cooled to the normal temperature and high pressure state through the No. 3 heat exchanger 6 enters the cold box 7 to be low-temperature liquefied, and then expands through the pressure reducing valve 8 and is sent to the liquid air storage tank 9. The unliquefied air passes through the gas output end of the liquid air storage tank 9. After flowing out, it enters the cold box 7 to release cold energy. In addition, in order to better meet the liquefied working air, the openings of the No. 1 four-way valve 30, the No. 3 four-way valve 32, and the No. 2 valve 25 are adjusted respectively to control the flow of the heat transfer medium in the No. 1 cold storage filling bed 28, the heat transfer medium in the No. 2 cold storage filling bed 22, and the liquid natural gas to ensure that the working air temperature at the output end of the cold box remains stable. In addition, after the liquefied natural gas is vaporized in the cold box 7, it is converted into low-temperature gaseous natural gas, and then enters the heater 29 to provide cooling capacity for users.

[0040] Gasified liquid air expansion generator system: The gasified liquid air expansion and power generation subsystem includes a No. 4 valve 35, a No. 2 cryogenic pump 10, an evaporator 11, a No. 3 four-way valve 32, a No. 4 four-way valve 33, a No. 2 cold storage filled bed 22, a No. 4 heat exchanger 12, a No. 1 expander 13, a No. 5 heat exchanger 14, a No. 2 expander 15, a No. 6 heat exchanger 16, and a No. 3 expander 17. The No. 4 valve 35, the No. 2 cryogenic pump 10, the evaporator 11, the No. 4 heat exchanger 12, the No. 1 expander 13, the No. 5 heat exchanger 14, the No. 2 expander 15, the No. 6 heat exchanger 16, and the No. 3 expander 17 are connected in sequence, and the hot side of the evaporator 11 is connected to the No. 2 cold storage filled bed 22 through the No. 3 four-way valve 32 and the No. 4 four-way valve 33.

[0041] In the gasified liquid air expansion generating subsystem, the No. 4 valve output terminal 35b is connected to the No. 2 cryogenic pump input terminal 10a, the No. 2 cryogenic pump output terminal 10b is connected to the evaporator cold side input terminal 11c, the No. 4 heat exchanger cold side input terminal 12c is connected to the evaporator cold side output terminal 11d, the No. 4 heat exchanger cold side output terminal 12d is connected to the No. 1 expander input terminal 13a, the No. 1 expander output terminal 13b is connected to the No. 5 heat exchanger cold side input terminal 14c, the No. 5 heat exchanger cold side output terminal 14d is connected to the No. 2 expander input terminal 15a, the No. 2 expander output terminal 15b is connected to the No. 6 heat exchanger cold side input terminal 16c, the No. 6 heat exchanger cold side output terminal 16d is connected to the No. 3 expander input terminal The output terminal 17a of the No. 3 expansion machine is connected to the outside world, the hot side input terminal 11a of the evaporator is connected to the second output terminal 33d of the No. 4 four-way valve, the hot side output terminal 11b of the evaporator is connected to the second input terminal 33c of the No. 3 four-way valve, the second output terminal 32d of the No. 3 four-way valve is connected to the input terminal 22a of the No. 2 cold storage filled bed, the first input terminal 33a of the No. 4 four-way valve is connected to the output terminal 22b of the No. 2 cold storage filled bed, the No. 2 valve inlet 25a is connected to the separator output terminal 24c, the No. 2 valve output terminal 25b is connected to the second input terminal 7c of the cold box, wherein a No. 1 flow controller 101 is provided, and the second input terminal 7c of the cold box is connected to the cold side output terminal 29a of the heater.

[0042] Liquid air flows out from the liquid output end of the liquid air storage tank 9, is sucked and pressurized by the No. 2 cryogenic pump 10, and is sent to the evaporator 11 for vaporization. The vaporized cold is sent to the No. 2 cold storage filling bed 22 for storage through the heat transfer medium, and is used when liquefying air in the energy storage mode. The vaporized air from the evaporator 11 enters the No. 4 heat exchanger 12, is heated by the heat transfer medium, and then enters the No. 1 expander 13 for expansion and power generation, then enters the No. 5 heat exchanger 14 for heating again, enters the No. 2 expander 15 for expansion and power generation, and finally enters the No. 6 heat exchanger 16 for heating, and then enters the No. 3 expander 17 for expansion and power generation.

[0043] Waste heat recovery circulation subsystem: The waste heat recovery circulation subsystem includes a cold oil tank 21, a No. 1 solution pump 20, a No. 1 heat exchanger 2, a No. 2 heat exchanger 4, a No. 3 heat exchanger 6, a hot oil tank 19, a No. 2 solution pump 18, a No. 4 heat exchanger 12, a No. 5 heat exchanger 14, and a No. 6 heat exchanger 16. The cold oil tank 21, the No. 1 solution pump 20, the No. 1 heat exchanger 2, the No. 2 heat exchanger 4, the No. 3 heat exchanger 6, the No. 4 heat exchanger 12, the No. 5 heat exchanger 14, and the No. 6 heat exchanger 16 are sequentially connected to form a waste heat recovery subsystem.

[0044] In the waste heat recovery subsystem, the No. 1 solution pump output terminal 20b is connected to the cold side input terminal 2c of the No. 1 heat exchanger, the cold side input terminal 4c of the No. 2 heat exchanger, and the cold side input terminal 6c of the No. 3 heat exchanger in sequence; the hot oil tank input terminal 19a is connected to the cold side output terminal 2d of the No. 1 heat exchanger, the cold side output terminal 4d of the No. 2 heat exchanger, and the cold side output terminal 6d of the No. 3 heat exchanger in sequence; the hot oil tank output terminal 19b is connected to the No. 2 solution pump input terminal 18a; the No. 2 solution pump output terminal 18b is connected to the hot side input terminal 12a of the No. 4 heat exchanger, the hot side input terminal 14a of the No. 5 heat exchanger, and the hot side input terminal 16a of the No. 6 heat exchanger in sequence; the cold oil tank input terminal 21a is connected to the hot side output terminal 12b of the No. 4 heat exchanger, the hot side output terminal 14b of the No. 5 heat exchanger, and the hot side output terminal 16b of the No. 6 heat exchanger in sequence; and the cold oil tank output terminal 21b is connected to the No. 1 solution pump input terminal 20a.

[0045] In the energy storage mode of the liquid air energy storage system, the heat transfer oil in the cold oil tank 21 is sucked by the solution pump 20 and sent to the cold side of the No. 1 heat exchanger 2, the No. 2 heat exchanger 4, and the No. 3 heat exchanger 6 to cool the high-temperature and high-pressure air at the compressor output end, and then the temperature of the heat transfer oil rises and enters the hot oil tank 19. In the energy release mode of the liquid air energy storage system, the high-temperature heat transfer oil in the hot oil tank 19 is sucked by the No. 2 solution pump 18 and sent to the No. 4 heat exchanger 12, the No. 5 heat exchanger 14, and the No. 6 heat exchanger 16 to preheat the low-temperature working air at the input end of each expander, and then the temperature of the heat transfer oil is reduced, and then it returns to the cold oil tank 21, and so on.

[0046] A No. 1 flow controller 101 is provided in the pipeline connecting the No. 2 valve 25 and the cold box 7, a No. 2 flow controller 102 is provided in the pipeline connecting the No. 2 four-way valve 31 and the cold box 7, a temperature controller 103 is provided in the pipeline connecting the pressure reducing valve 8 and the cold box 7, and a No. 3 flow controller 104 is provided in the pipeline connecting the No. 3 four-way valve 32 and the cold box 7.

[0047] The first output end 24b of the separator and the second output end 24c of the separator are provided with a No. 1 valve 26, and the No. 2 valve 25 is a cut-off valve, and the flow rate of the working medium can be adjusted by adjusting the valve opening. The No. 1 four-way valve 30 is respectively connected to the hot side input end 27a of the gasifier, the No. 1 cold storage filled bed input end 28a and the first output end 7b of the cold box. The first input end 30a of the No. 1 four-way valve is connected to the outside world and can be closed and opened according to the requirements of operation. When opened, the heat transfer medium can be supplemented. The No. 2 four-way valve 30 is respectively connected to the hot side output end 27b of the gasifier, the No. 1 cold storage filled bed output end 28b and the first input end 7a of the cold box. The No. 2 four-way valve second input end 31c can be closed and opened according to the requirements of operation, and the heat transfer medium can be released when opened. The No. 3 four-way valve 32 is respectively connected to the evaporator hot side output terminal 11b, the No. 2 cold storage filled bed input terminal 22a and the cold box fifth input terminal 7i. The No. 3 four-way valve first input terminal 32a is connected to the outside world and can be closed and opened according to the operation requirements. When opened, the heat transfer medium can be replenished. The No. 4 four-way valve second output terminal 33d is respectively connected to the evaporator hot side input terminal 11a, the No. 2 cold storage filled bed output terminal 22b and the cold box fifth output terminal 7j. The No. 4 four-way valve second input terminal 33c can be closed and opened according to the operation requirements. When opened, the heat transfer medium can be released.

[0048] The control method of the above system includes an energy storage mode, an energy release mode and a shutdown mode.

[0049] In the energy storage mode, the flow rate of the low-temperature heat transfer medium in the No. 1 cold storage filling bed is controlled, so that the low-temperature heat transfer medium enters the cold box through the output end of the No. 2 four-way valve to cool the working air, and the heat transfer medium after heat exchange enters the No. 1 cold storage filling bed through the No. 1 four-way valve. The flow rate of the low-temperature heat transfer medium in the No. 2 cold storage filling bed is controlled, and the low-temperature heat transfer medium flowing out of the No. 2 cold storage filling bed enters the cold box through the output end of the No. 4 four-way valve to cool the working air, and the heat transfer medium after heat exchange enters the No. 2 cold storage filling bed through the No. 3 four-way valve, and circulates in sequence. However, as the energy storage time continues to increase, the cold capacity in the No. 1 cold storage filling bed and the No. 2 cold storage filling bed continues to decrease, and the flow rate of liquid natural gas entering the cold box through the No. 2 valve is controlled to supplement the cold capacity of the system and ensure that the system liquefaction rate remains stable. In the energy release mode, adjust the valve opening of the first input end of the No. 1 four-way valve to control the flow of the heat transfer medium in the No. 1 cold storage filled bed, ensure the recovery of the liquefied natural gas vaporization cooling capacity in the vaporizer, and ensure that the temperature of the cold side output end of the vaporizer remains stable; adjust the valve opening of the first input end of the No. 3 four-way valve to control the flow of the heat transfer medium in the No. 2 cold storage filled bed, ensure the recovery of the liquefied air vaporization cooling capacity in the evaporator, and ensure that the temperature of the cold side output end of the evaporator remains stable.

[0050] Specifically, in the energy storage mode, open valve No. 34, close valve No. 1 and valve No. 4, 35, open valve No. 25, open the first input end 30a of the No. 1 four-way valve, the second input end 30c of the No. 1 four-way valve, and the second output end 30d of the No. 1 four-way valve, and close the first output end 30b of the No. 1 four-way valve, open the first output end 31b of the No. 2 four-way valve, the second input end 31c of the No. 2 four-way valve, and the second output end 31d of the No. 2 four-way valve, and close the first input end 31a of the No. 2 four-way valve, open the first input end 32a of the No. 3 four-way valve, the first output end 32b of the No. 3 four-way valve, and the second output end 32d of the No. 3 four-way valve, and close the second input end 32c of the No. 3 four-way valve, open the first input end 33a of the No. 4 four-way valve, the first output end 33b of the No. 4 four-way valve, and the second input end 33c of the No. 4 four-way valve, and close the The second output end 33d of the No. 4 four-way valve is opened, that is, the No. 3 valve 34, the No. 2 valve 25, the first input end of the No. 1 four-way valve 30, the second input end of the No. 1 four-way valve 30, the second output end of the No. 1 four-way valve 30, the first output end of the No. 2 four-way valve 31, the second input end of the No. 2 four-way valve 31, the second output end of the No. 2 four-way valve 31, the first input end of the No. 3 four-way valve 32, the second input end of the No. 3 four-way valve 32, the second output end of the No. 3 four-way valve 32, the first output end of the No. 4 four-way valve 33, the second input end of the No. 4 four-way valve 33, and the second output end of the No. 4 four-way valve 33 are opened, and the No. 4 valve 35, the No. 1 valve 26, the first output end of the No. 1 four-way valve 30, the first input end of the No. 2 four-way valve 31, the first output end of the No. 3 four-way valve 32, and the first output end of the No. 4 four-way valve 33 are closed. Start the compressed air vaporization subsystem and waste heat recovery subsystem, and shut down the LNG gasification subsystem and gasified liquid air expansion subsystem.

[0051] In addition, the first cold storage filling bed 28 and the second cold storage filling bed 22 already store the cold released by the gasification of liquid natural gas and liquid air. The working air flows through the third valve 34, the first compressor 1, the second compressor 3 and the third compressor 5 in sequence, and after being pressurized and heated, enters the first heat exchanger 2, the second heat exchanger 4 and the third heat exchanger 6 to cool down to room temperature, and then enters the cold box for further cooling. The low-temperature working air flows out from the third output end 7f of the cold box, enters the pressure reducing valve 8 to throttle and reduce pressure, and is converted into a gas-liquid two-phase state, and then enters the liquid air tank 9. The low-temperature gaseous working air flows out from the first gas output end 9b of the liquid air storage tank, flows into the cold box 7 from the fourth input end 7g of the cold box to cool, and then flows out from the cold box output end 7h. At the same time, the normal temperature heat transfer oil in the cold oil tank 21 is sucked by the solution pump 20 and sent to the first heat exchanger 2, the second heat exchanger 4 and the third heat exchanger 6 in sequence to cool the high-temperature working air.

[0052] When the cooling capacity in the No. 1 cold storage filled bed 28 and the No. 2 cold storage filled bed 22 is insufficient, the temperature of the third output terminal 7f of the cold box will rise due to insufficient cooling capacity, and the value of the temperature controller 103 will rise. The No. 1 flow controller 101, the No. 2 flow controller 102, and the No. 3 flow controller 104 are used to adjust and increase the flow of liquid air and the heat transfer medium in the No. 1 cold storage filled bed 28 and the No. 2 cold storage filled bed 22 to supplement the cooling capacity in the cold box, thereby meeting the stability of the liquefied air in the cold box and keeping the value of the temperature controller 103 stable.

[0053] In the energy storage mode, the cold in the No. 1 cold storage filled bed 28 cools the heat transfer medium, and the low-temperature heat transfer medium enters the cold box 7 through the second output end 31d of the No. 2 four-way valve to cool the working air. The heat transfer medium after heat exchange enters the No. 1 cold storage filled bed 28 through the No. 1 four-way valve 30. The cold in the No. 2 cold storage filled bed 22 cools the heat transfer medium, and the low-temperature heat transfer medium enters the cold box 7 through the first output end 33b of the No. 4 four-way valve to cool the working air. The heat transfer medium after heat exchange enters the No. 2 cold storage filled bed 22 through the No. 3 four-way valve 32, and circulates in sequence. However, as the energy storage time continues to increase, the cold in the No. 1 cold storage filled bed 28 and the No. 2 cold storage filled bed 22 continues to decrease. At this time, the liquid natural gas enters the cold box through the No. 2 valve 25 to supplement the cold capacity of the system to ensure that the system liquefaction rate remains stable.

[0054] In energy release mode; First, close valve No. 34 and valve No. 25, open valve No. 1 26 and valve No. 4 35, close the first input end 30a of the No. 1 four-way valve and the second input end 30c of the No. 1 four-way valve, open the first output end 30b of the No. 1 four-way valve and the second output end 30d of the No. 1 four-way valve, open the first output end 31b of the No. 2 four-way valve and the first input end 31a of the No. 2 four-way valve, close the second input end 31c of the No. 2 four-way valve and the second output end 31d of the No. 2 four-way valve, open the first output end 32b of the No. 3 four-way valve and the second output end 32d of the No. 3 four-way valve, close the first input end 32a of the No. 3 four-way valve and the second input end 32c of the No. 3 four-way valve, open the first input end 33a of the No. 4 four-way valve and the first output end 33b of the No. 4 four-way valve, close the second input end 31c of the No. 2 four-way valve and the second output end 31d of the No. 2 four-way valve 32c, the second output end 32d of the No. 4 four-way valve, that is, close the No. 3 valve 34, the No. 2 valve 25, the second input end of the No. 1 four-way valve 30, the second output end of the No. 2 four-way valve 31, the first output end of the No. 3 Stone valve, and the first input end of the No. 4 four-way valve; open the No. 4 valve 35, the No. 1 valve 26, the first input end of the No. 1 four-way valve 30, the first output end of the No. 1 four-way valve 30, the second input end of the No. 1 four-way valve 30, the first input end of the No. 2 four-way valve 31, the first output end of the No. 2 four-way valve 31, the second input end of the No. 2 four-way valve 31, the first input end of the No. 3 four-way valve 32, the second output end of the No. 3 four-way valve 32, the second input end of the No. 3 four-way valve 32, the first output end of the No. 4 four-way valve 33, the second output end of the No. 4 four-way valve 33, and the second input end of the No. 4 four-way valve 33.

[0055] Liquid air is sucked from the second output end 9c of the liquid air storage tank by the No. 3 solution pump 10 and sent to the evaporator 11 for gasification. The gaseous working air enters the No. 4 heat exchanger 12, the No. 5 heat exchanger 14, and the No. 6 heat exchanger 16 in sequence for heating and temperature rise, and then enters the No. 1 expander 13, the No. 2 expander 15, and the No. 3 expander 17 in sequence for expansion and power generation. The high-temperature heat transfer oil in the hot oil tank 19 is sucked by the No. 2 solution pump 18 and sent to the No. 4 heat exchanger 12, the No. 5 heat exchanger 14, and the No. 6 heat exchanger 16 in sequence for heating, and then merges and flows into the cold oil tank 21 for storage. The heat transfer medium in the No. 2 cold storage filling bed enters the evaporator 11 through the second output end 33d of the No. 4 four-way valve to heat the liquid working air. The cooled heat transfer medium enters the No. 2 cold storage filling bed 22 through the No. 3 four-way valve 32 to store cold. At the same time, liquid natural gas is sucked by the No. 1 cryogenic pump 23 and sent to the separator 24, and enters the vaporizer 27 through the No. 1 valve 26 to exchange heat with the heat transfer medium. The low-temperature heat transfer medium enters the No. 1 cold storage filling bed 28 through the No. 2 four-way valve 31 to store the cold energy.

[0056] Start the LNG gasification subsystem and the gasified liquid air expansion subsystem, and shut down the compressed air evaporation subsystem and the waste heat recovery subsystem.

[0057] In the shutdown mode, the No. 2 valve 25, the No. 3 valve 34, the No. 4 valve 35, the No. 3 four-way valve 32, and the No. 4 four-way valve 33 are closed, the first input end 30a of the No. 1 four-way valve and the second input end 30c of the No. 1 four-way valve are closed, the first output end 30b of the No. 1 four-way valve and the second output end 30d of the No. 1 four-way valve are opened, the second input end 31c of the No. 2 four-way valve and the first input end 31a of the No. 2 four-way valve are opened, and the second output end 31d of the No. 2 four-way valve and the first output end 31b of the No. 2 four-way valve are closed; the liquid natural gas is sucked by the No. 1 cryogenic pump 23 and sent to the separator 24, and enters the vaporizer 27 through the No. 1 valve 26 to exchange heat with the heat transfer medium, and the low-temperature heat transfer medium enters the No. 1 cold storage filled bed 28 through the No. 2 four-way valve 31 to store the cold energy.

[0058] Start the LNG gasification subsystem, and shut down the gasification liquid air expansion subsystem, compressed air evaporation subsystem, and waste heat recovery subsystem.

[0059] A temperature controller 103 is provided upstream of the pressure reducing valve 8. In the energy storage mode, valve No. 2 25, four-way valve No. 1 30, four-way valve No. 2 31, four-way valve No. 32 and four-way valve No. 4 33 are opened, and the valve openings of valve No. 2 25, four-way valve No. 1 30, four-way valve No. 2 31, four-way valve No. 32 and four-way valve No. 4 33 are controlled by adjusting flow controller No. 1 101, flow controller No. 2 102 and flow controller No. 3 104, so as to ensure that the temperature of the output end 7f of the cold box remains consistent and is not affected by the reduction in the cooling capacity of the cold storage filling bed.

[0060] The temperature of the cold box output end 7f is continuously increased due to the influence of the No. 1 cold storage filled bed 28 and the No. 2 cold storage filled bed 22. By adjusting the opening of the No. 2 valve 25, the No. 1 four-way valve 30, and the No. 3 four-way valve 32, the flow rate of liquid natural gas and heat transfer medium is increased, thereby increasing the cooling capacity in the liquid air energy storage system with cold storage filled beds, so as to achieve the temperature of the cold box output end 7f to remain consistent.

[0061] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0062] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A liquid air energy storage system coupled with LNG cold energy, characterized in that: It includes LNG gasification subsystem, compressed air liquefaction subsystem, gasified liquid air expansion and power generation subsystem and waste heat recovery circulation subsystem; The LNG gasification subsystem comprises a No. 1 cryogenic pump (23), a separator (24), a No. 1 valve (26) and a vaporizer (27) which are connected in sequence, and a No. 1 packed bed cold storage device (28) which is connected to the vaporizer (27) at both ends via a No. 1 four-way valve (30) and a No. 2 four-way valve (31) respectively; The compressed air liquefaction subsystem includes a No. 3 valve (34), a No. 1 compressor (1), a No. 1 heat exchanger (2), a No. 2 compressor (3), a No. 2 heat exchanger (4), a No. 3 compressor (5), a No. 3 heat exchanger (6), a cold box (7), a temperature controller (103), a pressure reducing valve (8) and a liquid air storage tank (9) connected in sequence, as well as a No. 1 flow controller (101), a No. 2 flow controller (102), a No. 2 cold storage packed bed (22), a No. 2 valve (25), a heater (29), a No. 3 four-way valve (32), a No. 4 four-way valve (33) and a No. 3 flow controller (104); The two ends of the cold box (7) are connected to the first cold storage filling bed (28) through a first four-way valve (30) and a second four-way valve (31), respectively, and a second flow controller (102) is provided in the connecting pipe between the second four-way valve (31) and the cold box (7); The two ends of the cold box (7) are also connected to the second valve (25) and the heater (29), and a first flow controller (101) is provided in the connecting pipe between the second valve (25) and the cold box (7); The two ends of the No. 2 cold storage filled bed (22) are connected to the cold box (7) via a No. 3 four-way valve (32) and a No. 4 four-way valve (33), respectively, and a No. 3 flow controller (104) is provided in the connecting pipe between the No. 3 four-way valve (32) and the cold box (7); The gasified liquid air expansion and generation subsystem comprises a No. 4 valve (35), a No. 2 cryogenic pump (10), an evaporator (11), a No. 4 heat exchanger (12), a No. 1 expander (13), a No. 5 heat exchanger (14), a No. 2 expander (15), a No. 6 heat exchanger (16) and a No. 3 expander (17) which are connected in sequence; The hot side of the evaporator (11) is connected to the second cold storage filled bed (22) via a third four-way valve (32) and a fourth four-way valve (33); The waste heat recovery subsystem comprises a cold oil tank (21), a No. 1 solution pump (20), a hot oil tank (19), and a No. 2 solution pump (18). The cold oil tank (21) is connected in sequence to the No. 1 solution pump (20), the No. 1 heat exchanger (2), the No. 2 heat exchanger (4), the No. 3 heat exchanger (6), the No. 4 heat exchanger (12), the No. 5 heat exchanger (14), and the No. 6 heat exchanger (16).

2. A liquid air energy storage system coupled with LNG cold energy according to claim 1, characterized in that: The output end of the No. 1 cryogenic pump (23) in the LNG gasification subsystem is connected to the input end of the separator (24), the first output end of the separator (24) is connected to the input end of the No. 1 valve (26), the output end of the No. 1 valve (26) is connected to the cold side input end of the vaporizer (27), the first output end of the No. 1 four-way valve (30) is connected to the hot side input end of the vaporizer (27), the first input end of the No. 2 four-way valve (31) is connected to the hot side output end of the vaporizer (27), the second output end of the No. 1 four-way valve (30) is connected to the input end of the No. 1 packed bed cold storage device (28), and the first output end of the No. 2 four-way valve (31) is connected to the output end of the No. 1 packed bed cold storage device (28).

3. A liquid air energy storage system coupled with LNG cold energy according to claim 1, characterized in that: The output end of valve No. 3 (34) in the compressed air liquefaction subsystem is connected to the input end of compressor No. 1 (1), the output end of compressor No. 1 (1) is connected to the hot side input end of heat exchanger No. 1 (2), the hot side output end of heat exchanger No. 1 (2) is connected to the input end of compressor No. 2 (3), the output end of compressor No. 2 (3) is connected to the hot side input end of heat exchanger No. 2 (4), the hot side output end of heat exchanger No. 2 (4) is connected to the input end of compressor No. 3 (5), the output end of compressor No. 3 (5) is connected to the hot side input end of heat exchanger No. 3 (6), the hot side output end of heat exchanger No. 3 (6) is connected to the third input end of cold box (7), the third output end of cold box (7) is connected to the input end of pressure reducing valve (8), the output end of pressure reducing valve (8 ... The first end of the cold box (7) is connected to the input end of the liquid air storage tank (9), the gas output end of the liquid air storage tank (9) is connected to the fourth input end of the cold box (7), the first input end of the cold box (7) is connected to the output end of the No. 2 four-way valve (31), the first output end of the cold box (7) is connected to the second input end of the No. 1 four-way valve (30), the first output end of the No. 3 four-way valve (32) is connected to the fifth input end of the cold box (7), the fifth output end of the cold box (7) is connected to the input end of the No. 4 four-way valve (33), the inlet of the No. 2 valve (25) is connected to the second output end of the separator (24), the output end of the No. 2 valve (25) is connected to the third input end of the cold box (7), and the third input end of the cold box (7) is connected to the cold side output end of the heater (29).

4. A liquid air energy storage system coupled with LNG cold energy according to claim 1, characterized in that: The output end of the No. 4 valve (35) in the gasified liquid air expansion and generating subsystem is connected to the input end of the No. 2 cryogenic pump (10), the output end of the No. 2 cryogenic pump (10) is connected to the cold side input end of the evaporator (11), the cold side input end of the No. 4 heat exchanger (12) is connected to the cold side output end of the evaporator (11), the cold side output end of the No. 4 heat exchanger (12) is connected to the input end of the No. 1 expander (13), the output end of the No. 1 expander (13) is connected to the cold side input end of the No. 5 heat exchanger (14), the cold side output end of the No. 5 heat exchanger (14) is connected to the input end of the No. 2 expander (15), and the No. 2 expander (15) is connected to the cold side input end of the No. 5 heat exchanger (14). The output end of the heat exchanger (5) is connected to the cold side input end of the sixth heat exchanger (16), the cold side output end of the sixth heat exchanger (16) is connected to the input end of the third expander (17), the output end of the third expander (17) is connected to the outside, the hot side input end of the evaporator (11) is connected to the output end of the fourth four-way valve (33), the hot side output end of the evaporator (11) is connected to the second input end of the third four-way valve (32), the second output end of the third four-way valve (32) is connected to the input end of the second cold storage filled bed (22), and the first input end of the fourth four-way valve (33) is connected to the output end of the second cold storage filled bed (22).

5. A liquid air energy storage system coupled with LNG cold energy according to claim 1, characterized in that: The output end of the No. 1 solution pump (20) in the waste heat recovery subsystem is connected to the cold side input end of the No. 1 heat exchanger (2), the cold side input end of the No. 2 heat exchanger (4), and the cold side input end of the No. 3 heat exchanger (6) in sequence; the input end of the hot oil tank (19) is connected to the cold side output end of the No. 1 heat exchanger (2), the cold side output end of the No. 2 heat exchanger (4), and the cold side output end of the No. 3 heat exchanger (6) in sequence; the output end of the hot oil tank (19) is connected to the input end of the No. 2 solution pump (18). The output end of the No. 2 solution pump (18) is connected to the hot side input end of the No. 4 heat exchanger (12), the hot side input end of the No. 5 heat exchanger (14), and the hot side input end of the No. 6 heat exchanger (16) in sequence; the input end of the cold oil tank (21) is connected to the hot side output end of the No. 4 heat exchanger (12), the hot side output end of the No. 5 heat exchanger (14), and the hot side output end of the No. 6 heat exchanger (16) in sequence; and the output end of the cold oil tank (21) is connected to the input end of the No. 1 solution pump (20).

6. A liquid air energy storage system coupled with LNG cold energy according to claim 1, characterized in that: The first valve (26) and the second valve (25) are connected to the first and second output ends of the separator (24); the first valve (26) and the second valve (25) are cut-off valves, and the flow rate of the working fluid is adjusted by adjusting the valve opening; The No. 1 four-way valve (30) is respectively connected to the hot side output end of the gasifier (27), the input end of the No. 1 cold storage filling bed (28), and the first output end of the cold box (7); the first input end of the No. 1 four-way valve (30) is connected to the outside world and is closed and opened according to the operation requirements. When opened, the heat transfer medium is replenished; The No. 2 four-way valve (31) is respectively connected to the cold side output end of the gasifier (27), the output end of the No. 1 cold storage filled bed (28), and the first input end of the cold box (7); the second input end of the No. 2 four-way valve (31) can be closed and opened according to the operation requirements, and the heat transfer medium can be released when it is opened; The No. 3 four-way valve (32) is respectively connected to the hot side output end of the evaporator (11), the input end of the No. 2 cold storage filled bed (22) and the fifth input end of the cold box (7); the first input end of the No. 3 four-way valve (32) is connected to the outside world and can be closed and opened according to the operation requirements. When opened, the heat transfer medium can be replenished; The second output end of the No. 4 four-way valve (33) is respectively connected to the hot side input end of the evaporator (11), the output end of the No. 2 cold storage filled bed (22), and the fifth output end of the cold box (7). The second input end of the No. 4 four-way valve (33) can be closed and opened according to the requirements of operation, and the heat transfer medium can be released when opened.

7. A control method for a liquid air energy storage system coupled with LNG cold energy, characterized in that: In energy storage mode control; First, open valve No. 3 (34), close valve No. 1 (26) and valve No. 4 (35), open valve No. 2 (25), open the first input end, the second input end, and the second output end of the No. 1 four-way valve (30), close the first output end of the No. 1 four-way valve (30), open the second input end, the first output end, and the second output end of the No. 2 four-way valve (31), close the first input end of the No. 2 four-way valve (31), open the first input end, the first output end, and the second output end of the No. 3 four-way valve (32), close the second input end of the No. 3 four-way valve (32), open the first input end, the first output end, and the second input end of the No. 4 four-way valve (33), and close the second output end of the No. 4 four-way valve (33); At this time, the first cold storage filling bed (28) and the second cold storage filling bed (22) already store cold energy released by the gasification of liquid natural gas and liquid air; the working air flows through the third valve (34), the first compressor (1), the second compressor (3) and the third compressor (5) in sequence, and after being pressurized and heated, enters the first heat exchanger (2), the second heat exchanger (4) and the third heat exchanger (6), where it is cooled to room temperature and then enters the cold box for further cooling; the low-temperature working air flows out from the third output end of the cold box (7) and enters the pressure reducing valve (8) is throttled and depressurized to change into a gas-liquid two-phase state, and then enters the liquid air tank (9). The low-temperature gaseous working air flows out from the output end of the liquid air tank gas (9), flows into the cold box (7) from the fourth input end of the cold box (7) to be cooled, and then flows out from the fourth output end of the cold box (7); at the same time, the normal-temperature heat transfer oil in the cold oil tank (21) is sucked by the solution pump (20) and sent to the first heat exchanger (2), the second heat exchanger (4), and the third heat exchanger (6) in sequence to cool the high-temperature working air; In the energy storage mode, the cold in the No. 1 cold storage filled bed (28) cools the heat transfer medium, and the low-temperature heat transfer medium enters the cold box (7) through the second output end of the No. 2 four-way valve (31) to cool the working air. The heat transfer medium after heat exchange enters the No. 1 cold storage filled bed (28) through the No. 1 four-way valve (30); the cold in the No. 2 cold storage filled bed (22) cools the heat transfer medium, and the low-temperature heat transfer medium enters the cold box (7) through the first output end of the No. 4 four-way valve (33) to cool the working air. The heat transfer medium after heat exchange enters the No. 2 cold storage filled bed (22) through the No. 3 four-way valve (32), and the cycle is repeated in sequence. As the energy storage time increases, the cold in the No. 1 cold storage filled bed (28) and the No. 2 cold storage filled bed (22) decreases continuously. At this time, liquid natural gas enters the cold box through the No. 2 valve (25) to supplement the cold capacity of the system, ensuring that the system liquefaction rate remains stable.

8. The control method according to claim 7, characterized in that: When the energy release mode is controlled, first, the No. 3 valve (34) and the No. 2 valve (25) are closed, the No. 1 valve (26) and the No. 4 valve (35) are opened, the first input end and the second input end of the No. 1 four-way valve (30) are closed, the first output end and the second output end of the No. 1 four-way valve (30) are opened, the first output end and the first input end of the No. 2 four-way valve (31) are opened, the second input end and the second output end of the No. 2 four-way valve (31) are closed, the first output end and the second output end of the No. 3 four-way valve (32) are opened, the first input end and the second input end of the No. 3 four-way valve (32) are closed, the first input end and the first output end of the No. 4 four-way valve (33) are opened, and the second input end and the second output end of the No. 4 four-way valve (33) are closed; Liquid air is sucked from the output end of the liquid air storage tank (9) by the No. 3 solution pump (10) and sent to the evaporator (11) for gasification. The gaseous working air enters the No. 4 heat exchanger (12), the No. 5 heat exchanger (14), and the No. 6 heat exchanger (16) in sequence for heating and then enters the No. 1 expander (13), the No. 2 expander (15), and the No. 3 expander (17) in sequence for expansion and power generation. The high-temperature heat transfer oil in the hot oil tank (19) is sucked by the No. 2 solution pump (18) and sequentially sent to the No. 4 heat exchanger (12), the No. 5 heat exchanger (14) and the No. 6 heat exchanger (16) for heating, and then merged and flowed into the cold oil tank (21) for storage. The heat transfer medium in the No. 2 cold storage filling bed enters the evaporator (11) through the second output end of the No. 4 four-way valve (33) to heat the liquid working air. The cooled heat transfer medium enters the No. 2 cold storage filling bed (22) through the No. 3 four-way valve (32) to store cold energy. At the same time, the liquid natural gas is sucked by the No. 1 low-temperature pump (23) and sent to the separator (24). It enters the vaporizer (27) through the No. 1 valve (26) to exchange heat with the heat transfer medium. The low-temperature heat transfer medium enters the No. 1 cold storage filling bed (28) through the No. 2 four-way valve (31) to store cold energy.

9. The control method according to claim 7, characterized in that: When the machine is in shutdown mode, the second valve (25), the third valve (34), the fourth valve (35), the third four-way valve (32), and the fourth four-way valve (33) are closed; the first input end and the second input end of the first four-way valve (30) are closed; the first output end and the second output end of the first four-way valve (30) are opened; the second input end and the first input end of the second four-way valve (31) are opened; and the second output end and the first output end of the second four-way valve (31) are closed; The liquid natural gas is sucked by the No. 1 cryogenic pump (23), sent to the separator (24), and enters the vaporizer (27) through the No. 1 valve (26) to exchange heat with the heat transfer medium. The low-temperature heat transfer medium enters the No. 1 cold storage filling bed (28) through the No. 2 four-way valve (31) to store the cold energy.

10. The control method according to claim 7, characterized in that: In the energy storage mode, the No. 2 valve (25), the No. 1 four-way valve (30), the No. 2 four-way valve (31), the No. 3 four-way valve (32), and the No. 4 four-way valve (33) are opened, and the No. 1 flow controller (101), the No. 2 flow controller (102), and the No. 3 flow controller (104) are adjusted to control the valve openings of the No. 2 valve (25), the No. 1 four-way valve (30), the No. 2 four-way valve (31), the No. 3 four-way valve (32), and the No. 4 four-way valve (33), so that the temperature of the third output end of the cold box (7) remains consistent and is not affected by the reduction in the cooling capacity of the cold storage filled bed; The temperature of the third output end of the cold box (7) is continuously increased due to the influence of the first cold storage filled bed (28) and the second cold storage filled bed (22). By adjusting the opening of the second valve (25), the first four-way valve (30), and the third four-way valve (32), the flow rate of the liquid natural gas and the heat transfer medium is increased, thereby increasing the cooling capacity in the liquid air energy storage system with the cold storage filled bed, so that the temperature of the third output end of the cold box (7) remains consistent.

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