Liquid air energy storage power generation device and method based on packed bed cascade cold storage

Abstract

The invention relates to the technical field of liquid air energy storage and cold energy storage, in particular to a liquid air energy storage power generation device and method based on packed bed cascade cold accumulation, and the liquid air energy storage power generation device comprises a liquid air supply unit, a cold energy cascade storage and exchange unit and an air expansion power generation unit. Liquid air is pressurized by a low-temperature pump and then enters the cold energy cascade storage and exchange unit, graded vaporization is carried out to release cold energy, the vaporized air enters the air expansion power generation unit to carry out expansion power generation, the air with residual pressure after power generation is completed serves as heat exchange fluid to enter the cold energy cascade storage and exchange unit, and low-temperature cold energy is recovered in a graded mode and stored in a cascade mode. Through graded heat exchange and cascade cold storage, the heat exchange temperature difference is reduced, the temperature gradient of the packed bed is reduced, then the cold loss in the heat exchange and cold storage process is reduced, and the system efficiency is improved. In addition, the residual pressure generated after air power generation is used as driving, an additional circulating fan is not needed, and the investment cost can be reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid air energy storage and cold energy storage, and in particular to a liquid air energy storage power generation device and method based on packed bed step cold storage. Background Art

[0002] Liquid air energy storage is one of the effective energy storage technologies for the imbalance between electricity supply and demand. During low electricity consumption (charging process), electricity is input into the system to liquefy air, so that electricity can be stored in the form of liquid air; during peak electricity consumption (discharging process), liquid air is pressurized, heated and other processes to drive the expansion generator to output electricity. Liquid air energy storage has the characteristics of high energy storage density, short response time, environmental friendliness, low levelized cost of energy (LCOE) and no geographical restrictions, and has received widespread attention.

[0003] During the operation of liquid air energy storage, the efficient cold storage of liquid air evaporation cold energy during power generation is the key to improving the thermodynamics and economy of the system. Cold storage packed beds are a conventional form of cold storage for liquid air energy storage systems. Traditional cold storage packed beds have low cold exergy recovery and storage efficiency due to the large heat exchange temperature difference on the heat exchanger side of the system loop and the wide heat exchange / cold storage temperature range of the bed. In addition, conventional cold storage packed beds require independent fans to provide power, which consumes a lot of power. Summary of the invention

[0004] The purpose of the present invention is to solve the shortcomings of the prior art and propose a liquid air energy storage power generation device and method based on packed bed cascade cold storage, which reduces the heat exchange temperature difference and the packed bed temperature gradient through graded heat exchange and cascade cold storage, thereby reducing the cooling loss in the heat exchange and cold storage process and improving the system efficiency. In addition, the present invention uses the residual pressure after air power generation as a drive, does not require an additional circulation fan, and can reduce investment costs.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: A liquid air energy storage power generation device based on packed bed cascade cold storage, comprising a liquid air supply unit, a cold energy cascade storage and exchange unit and an air expansion power generation unit; the liquid air supply unit is connected to the cold energy cascade storage and exchange unit, and the cold energy cascade storage and exchange unit is connected to the air expansion power generation unit; The liquid air in the liquid air supply unit may come from the liquid air energy storage charging process during the low electricity consumption period; the liquid air supply unit is used to provide air medium and power for the liquid air power generation process, and the pressurized liquid air is transmitted to the cold energy cascade storage and exchange unit; The cold energy cascade storage and exchange unit vaporizes the received liquid air in stages, stores the vaporized cold energy in stages, and transmits the vaporized air to the air expansion power generation unit; The air expansion power generation unit heats the received gaseous air and sends it to the expansion generator for expansion and power generation, and transmits the discharged air with residual pressure as a heat exchange fluid to the cold energy cascade storage and exchange unit to participate in the recovery and storage of liquid air cold energy; the air is finally discharged to the outside by the cold energy cascade storage and exchange unit.

[0006] Preferably, the liquid air supply unit comprises a liquid air storage tank and a cryogenic pump; the liquid air input of the liquid air storage tank may come from the liquid air energy storage charging process during low electricity consumption, and the output end of the liquid air storage tank is connected to the input end of the cryogenic pump; the output end of the cryogenic pump is connected to the first input end of the cold energy cascade storage and exchange unit as the output end of the liquid air supply unit.

[0007] Preferably, the cold energy cascade storage and exchange unit comprises a first heat exchanger, a second heat exchanger, a third heat exchanger, a fourth heat exchanger, a first cold storage filled bed, a second cold storage filled bed, a third cold storage filled bed, a fourth cold storage filled bed, a fifth cold storage filled bed, a sixth cold storage filled bed and a seventh cold storage filled bed; The first input end of the first heat exchanger is connected to the output end of the liquid air supply unit as the first input end of the cold energy cascade storage and exchange unit, and the first output end of the first heat exchanger is connected to the first input end of the second heat exchanger; the first output end of the second heat exchanger is connected to the first input end of the third heat exchanger; the first output end of the third heat exchanger is connected to the first input end of the fourth heat exchanger; the first output end of the fourth heat exchanger is connected to the input end of the air expansion power generation unit as the first output end of the cold energy cascade storage and exchange unit; The second input end of the fourth heat exchanger is connected to the output end of the air expansion power generation unit as the second input end of the cold energy cascade storage and exchange unit, and the second output end of the fourth heat exchanger is connected to the input end of the first cold storage filled bed; the output end of the first cold storage filled bed is connected to the second input end of the third heat exchanger; the second output end of the third heat exchanger is connected to the input end of the second cold storage filled bed; the output end of the second cold storage filled bed is connected to the second input end of the second heat exchanger; the second output end of the second heat exchanger is connected to the input end of the third cold storage filled bed; the output end of the third cold storage filled bed is connected to the second input end of the first heat exchanger; the second output end of the first heat exchanger is connected to the input end of the fourth cold storage filled bed; the output end of the fourth cold storage filled bed is connected to the input end of the fifth cold storage filled bed; the output end of the fifth cold storage filled bed is connected to the input end of the sixth cold storage filled bed; the output end of the sixth cold storage filled bed is connected to the input end of the seventh cold storage filled bed; the output end of the seventh cold storage filled bed is connected to the environment as the second output end of the cold energy cascade storage and exchange unit.

[0008] Preferably, the air expansion power generation unit comprises a fifth heat exchanger, a first expansion generator, a sixth heat exchanger, a second expansion generator, a seventh heat exchanger, a third expansion generator, an eighth heat exchanger and a fourth expansion generator; The input end of the fifth heat exchanger is connected to the first output end of the cold energy cascade storage and exchange unit as the input end of the air expansion power generation unit; the output end of the fifth heat exchanger is connected to the input end of the first expansion generator; the output end of the first expansion generator is connected to the input end of the sixth heat exchanger; the output end of the sixth heat exchanger is connected to the input end of the second expansion generator; the output end of the second expansion generator is connected to the input end of the seventh heat exchanger; the output end of the seventh heat exchanger is connected to the input end of the third expansion generator; the output end of the third expansion generator is connected to the input end of the eighth heat exchanger; the output end of the eighth heat exchanger is connected to the input end of the fourth expansion generator; the output end of the fourth expansion generator is connected to the second input end of the cold energy cascade storage and exchange unit as the output end of the air expansion power generation unit.

[0009] The present invention also provides a liquid air energy storage power generation method based on packed bed cascade cold storage, which is implemented based on the above-mentioned liquid air energy storage power generation device based on packed bed cascade cold storage, and includes: Liquid air flows out from the liquid air storage tank, and the low-temperature pump pressurizes it to provide circulation power. The liquid air is pumped to the first heat exchanger, the second heat exchanger, the third heat exchanger, and the fourth heat exchanger for staged vaporization; the vaporized air enters the air expansion power generation unit for multi-stage heating and expansion power generation; the air with residual pressure after expansion enters the cold energy cascade storage and exchange unit as a heat exchange fluid to stage-heat the liquid air and recover the vaporized cold energy to the first cold storage filled bed, the second cold storage filled bed, the third cold storage filled bed, the fourth cold storage filled bed, the fifth cold storage filled bed, the sixth cold storage filled bed, and the seventh cold storage filled bed for staged storage; finally, the air is discharged into the environment from the seventh cold storage filled bed.

[0010] Preferably, the vaporization cold energy of liquid air is stored in a plurality of cold storage packed beds in a staged manner, wherein the first cold storage packed bed and the seventh cold storage packed bed store low-grade cold energy, the second cold storage packed bed and the sixth cold storage packed bed store medium-grade cold energy, the third cold storage packed bed and the fifth cold storage packed bed store medium- and high-grade cold energy, and the fourth cold storage packed bed stores high-grade cold energy.

[0011] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention adopts graded heat exchange to reduce the heat exchange temperature difference of the heat exchanger for vaporizing liquid air in the power generation process, realizes small temperature difference heat exchange of the heat exchanger, and reduces the refrigeration loss in the heat exchanger.

[0012] 2. The present invention adopts stepped cold storage to reduce the storage temperature gradient of the cold storage packed bed, avoids the mixing of cold energy of different energy levels in the storage stage, and reduces the cold exergy loss in the cold storage packed bed.

[0013] 3. The present invention utilizes the residual pressure after air power generation as a drive, does not require an additional circulation fan, and can reduce investment costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic structural diagram of the power generation device of the present invention.

[0015] In the figure: 100 liquid air supply unit, 101 liquid air storage tank, 102 cryogenic pump; 200 cold energy cascade storage and exchange unit, 201 first heat exchanger, 202 second heat exchanger, 203 third heat exchanger, 204 fourth heat exchanger; 205 first cold storage filled bed, 206 second cold storage filled bed, 207 third cold storage filled bed, 208 fourth cold storage filled bed, 209 fifth cold storage filled bed, 2010 sixth cold storage filled bed, 2011 seventh cold storage filled bed; 300 air expansion power generation unit, 301 fifth heat exchanger, 302 first expansion generator, 303 sixth heat exchanger, 304 second expansion generator, 305 seventh heat exchanger, 306 third expansion generator, 307 eighth heat exchanger, 308 fourth expansion generator. DETAILED DESCRIPTION

[0016] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings, so that those skilled in the art can better understand the advantages and features of the present invention, thereby making a clearer definition of the protection scope of the present invention. The embodiments described in the present invention are only a part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present invention.

[0017] A liquid air energy storage power generation device based on packed bed cascade cold storage, comprising a liquid air supply unit, a cold energy cascade storage and exchange unit and an air expansion power generation unit; the liquid air supply unit is connected to the cold energy cascade storage and exchange unit, and the cold energy cascade storage and exchange unit is connected to the air expansion power generation unit; The liquid air in the liquid air supply unit 100 may come from the liquid air energy storage charging process during the low electricity consumption period; the liquid air supply unit 100 is used to provide air medium and power for the liquid air power generation process, and the pressurized liquid air is transmitted to the cold energy cascade storage and exchange unit 200; The cold energy cascade storage and exchange unit 200 vaporizes the received liquid air in stages, stores the vaporized cold energy in stages, and transmits the vaporized air to the air expansion power generation unit 300; The air expansion power generation unit 300 heats the received gaseous air and sends it to the expansion generator for expansion and power generation, and transmits the discharged air with residual pressure as a heat exchange fluid to the cold energy cascade storage and exchange unit 200 to participate in the recovery and storage of liquid air cold energy; the air is finally discharged to the outside by the cold energy cascade storage and exchange unit 200.

[0018] Specifically, the liquid air supply unit 100 includes a liquid air storage tank 101 and a cryogenic pump 102; the liquid air input of the liquid air storage tank 101 can come from the liquid air energy storage charging process during low electricity consumption, and the output end of the liquid air storage tank 101 is connected to the input end of the cryogenic pump 102; the output end of the cryogenic pump 102 is connected to the first input end of the cold energy cascade storage and exchange unit 200 as the output end of the liquid air supply unit 100.

[0019] Specifically, the cold energy cascade storage and exchange unit 200 includes a first heat exchanger 201, a second heat exchanger 202, a third heat exchanger 203, a fourth heat exchanger 204, a first cold storage filled bed 205, a second cold storage filled bed 206, a third cold storage filled bed 207, a fourth cold storage filled bed 208, a fifth cold storage filled bed 209, a sixth cold storage filled bed 2010 and a seventh cold storage filled bed 2011; The first input end of the first heat exchanger 201 is connected to the output end of the liquid air supply unit 100 as the first input end of the cold energy cascade storage and exchange unit 200, and the first output end of the first heat exchanger 201 is connected to the first input end of the second heat exchanger 202; the first output end of the second heat exchanger 202 is connected to the first input end of the third heat exchanger 203; the first output end of the third heat exchanger 203 is connected to the first input end of the fourth heat exchanger 204; the first output end of the fourth heat exchanger 204 is connected to the input end of the air expansion power generation unit 300 as the first output end of the cold energy cascade storage and exchange unit 200; The second input end of the fourth heat exchanger 204 is connected to the output end of the air expansion power generation unit 300 as the second input end of the cold energy cascade storage and exchange unit 200, and the second output end of the fourth heat exchanger 204 is connected to the input end of the first cold storage filled bed 205; the output end of the first cold storage filled bed 205 is connected to the second input end of the third heat exchanger 203; the second output end of the third heat exchanger 203 is connected to the input end of the second cold storage filled bed 206; the output end of the second cold storage filled bed 206 is connected to the second input end of the second heat exchanger 202; the second output end of the second heat exchanger 202 is connected to the output end of the third cold storage filled bed 207. The input end is connected; the output end of the third cold storage filled bed 207 is connected to the second input end of the first heat exchanger 201; the second output end of the first heat exchanger 201 is connected to the input end of the fourth cold storage filled bed 208; the output end of the fourth cold storage filled bed 208 is connected to the input end of the fifth cold storage filled bed 209; the output end of the fifth cold storage filled bed 209 is connected to the input end of the sixth cold storage filled bed 2010; the output end of the sixth cold storage filled bed 2010 is connected to the input end of the seventh cold storage filled bed 2011; the output end of the seventh cold storage filled bed 2011 is connected to the environment as the second output end of the cold energy cascade storage and exchange unit 200.

[0020] Specifically, the air expansion power generation unit 300 includes a fifth heat exchanger 301, a first expansion generator 302, a sixth heat exchanger 303, a second expansion generator 304, a seventh heat exchanger 305, a third expansion generator 306, an eighth heat exchanger 307 and a fourth expansion generator 308; The input end of the fifth heat exchanger 301 is connected to the first output end of the cold energy cascade storage and exchange unit 200 as the input end of the air expansion power generation unit 300; the output end of the fifth heat exchanger 301 is connected to the input end of the first expansion generator 302; the output end of the first expansion generator 302 is connected to the input end of the sixth heat exchanger 303; the output end of the sixth heat exchanger 303 is connected to the input end of the second expansion generator 304; the output end of the second expansion generator 304 is connected to the input end of the seventh heat exchanger 305; the output end of the seventh heat exchanger 305 is connected to the input end of the third expansion generator 306; the output end of the third expansion generator 306 is connected to the input end of the eighth heat exchanger 307; the output end of the eighth heat exchanger 307 is connected to the input end of the fourth expansion generator 308; the output end of the fourth expansion generator 308 is connected to the second input end of the cold energy cascade storage and exchange unit 200 as the output end of the air expansion power generation unit 300.

[0021] A liquid air energy storage power generation method based on packed bed cascade cold storage, the method is implemented based on the above-mentioned liquid air energy storage power generation device based on packed bed cascade cold storage, comprising: Liquid air flows out from the liquid air storage tank 101, and the low-temperature pump 102 pressurizes and provides circulation power. The liquid air is pumped to the first heat exchanger 201, the second heat exchanger 202, the third heat exchanger 203, and the fourth heat exchanger 204 for staged vaporization; the vaporized air enters the air expansion power generation unit 300 for multi-stage heating and expansion power generation; the air with residual pressure after expansion enters the cold energy cascade storage and exchange unit 200 as a heat exchange fluid to stage-heat the liquid air and recover the vaporized cold energy to the first cold storage filling bed 205, the second cold storage filling bed 206, the third cold storage filling bed 207, the fourth cold storage filling bed 208, the fifth cold storage filling bed 209, the sixth cold storage filling bed 2010, and the seventh cold storage filling bed 2011 for staged storage; finally, the air is discharged into the environment from the seventh cold storage filling bed 2011.

[0022] The liquid air is heat exchanged in stages through the first heat exchanger 201, the second heat exchanger 202, the third heat exchanger 203 and the fourth heat exchanger 204, which can reduce the heat exchange temperature difference between the cold and hot ends of the heat exchanger and reduce the refrigeration loss during the heat exchange process.

[0023] Specifically, the vaporized cold energy of liquid air is stored in multiple cold storage packed beds in a stepwise manner, wherein the first cold storage packed bed 205 and the seventh cold storage packed bed 2011 store low-grade cold energy, the second cold storage packed bed 206 and the sixth cold storage packed bed 2010 store medium-grade cold energy, the third cold storage packed bed 207 and the fifth cold storage packed bed 209 store medium- and high-grade cold energy, and the fourth cold storage packed bed 208 stores high-grade cold energy. By storing vaporized cold energy in multiple cold storage packed beds in a stepwise manner, the temperature gradient in each cold storage packed bed can be reduced, and the exergy loss during the storage process can be reduced. Example

[0024] Liquid air flows out of the liquid air storage tank 101 and is pumped by the cryogenic pump 102 to the first input end of the first heat exchanger 201 with a temperature of -175°C, the first input end of the second heat exchanger 202 with a temperature of -130°C, the first input end of the third heat exchanger 203 with a temperature of -90°C, the first input end of the fourth heat exchanger 204 with a temperature of -50°C, and the first output end with a temperature of -20°C. In this way, liquid air achieves graded heat exchange and cold energy recovery. The first cold storage filled bed 205 and the seventh cold storage filled bed 2011 store cold energy with a temperature gradient of -40°C to -10°C, the second cold storage filled bed 206 and the sixth cold storage filled bed 2010 store cold energy with a temperature gradient of -70°C to -40°C, the third cold storage filled bed 207 and the fifth cold storage filled bed 209 store cold energy with a temperature gradient of -110°C to -70°C, and the fourth cold storage filled bed 205 stores cold energy with a temperature gradient of -150°C to -110°C. In this way, liquid air cold energy is stored in a stepped manner.

[0025] In summary, the present invention reduces the heat exchange temperature difference and the temperature gradient of the packed bed through staged heat exchange and staged cold storage, thereby reducing the cooling loss in the heat exchange and cold storage process and improving the system efficiency. In addition, the present invention uses the residual pressure after air power generation as a drive, does not require an additional circulation fan, and can reduce investment costs.

[0026] The description and practice disclosed in the present invention are easy to think and understand for ordinary technicians in the technical field, and several improvements and modifications can be made without departing from the principles of the present invention. Therefore, modifications or improvements made without departing from the spirit of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A liquid air energy storage power generation device based on packed bed cascade cold storage, characterized in that: It comprises a liquid air supply unit (100), a cold energy cascade storage and exchange unit (200) and an air expansion power generation unit (300); the liquid air supply unit (100) is connected to the cold energy cascade storage and exchange unit (200), and the cold energy cascade storage and exchange unit (200) is connected to the air expansion power generation unit (300); The liquid air in the liquid air supply unit (100) comes from the liquid air energy storage charging process during the low electricity consumption period; the liquid air supply unit (100) is used to provide air medium and power for the liquid air power generation process, and the pressurized liquid air is transmitted to the cold energy cascade storage and exchange unit (200); The cold energy cascade storage and exchange unit (200) vaporizes the received liquid air in stages, stores the vaporized cold energy in stages, and transmits the vaporized air to the air expansion power generation unit (300); The air expansion power generation unit (300) heats the received gaseous air and sends it to the expansion generator for expansion and power generation, and transmits the discharged air with residual pressure as a heat exchange fluid to the cold energy cascade storage and exchange unit (200) to participate in the recovery and storage of liquid air cold energy; the air is finally discharged to the outside by the cold energy cascade storage and exchange unit (200).

2. A liquid air energy storage power generation device based on packed bed cascade cold storage according to claim 1, characterized in that: The liquid air supply unit (100) comprises a liquid air storage tank (101) and a cryogenic pump (102); the liquid air input of the liquid air storage tank (101) is derived from the liquid air energy storage charging process during a low electricity consumption period, and the output end of the liquid air storage tank (101) is connected to the input end of the cryogenic pump (102); the output end of the cryogenic pump (102) is connected to the first input end of the cold energy cascade storage and exchange unit (200) as the output end of the liquid air supply unit (100).

3. The liquid air energy storage power generation device based on packed bed cascade cold storage according to claim 1 is characterized in that: The cold energy cascade storage and exchange unit (200) comprises a first heat exchanger (201), a second heat exchanger (202), a third heat exchanger (203), a fourth heat exchanger (204), a first cold storage filled bed (205), a second cold storage filled bed (206), a third cold storage filled bed (207), a fourth cold storage filled bed (208), a fifth cold storage filled bed (209), a sixth cold storage filled bed (2010) and a seventh cold storage filled bed (2011); The first input end of the first heat exchanger (201) is connected to the output end of the liquid air supply unit (100) as the first input end of the cold energy cascade storage and exchange unit (200); the first output end of the first heat exchanger (201) is connected to the first input end of the second heat exchanger (202); the first output end of the second heat exchanger (202) is connected to the first input end of the third heat exchanger (203); the first output end of the third heat exchanger (203) is connected to the first input end of the fourth heat exchanger (204); the first output end of the fourth heat exchanger (204) is connected to the input end of the air expansion power generation unit (300) as the first output end of the cold energy cascade storage and exchange unit (200); The second input end of the fourth heat exchanger (204) is connected to the output end of the air expansion power generation unit (300) as the second input end of the cold energy cascade storage and exchange unit (200); the second output end of the fourth heat exchanger (204) is connected to the input end of the first cold storage filled bed (205); the output end of the first cold storage filled bed (205) is connected to the second input end of the third heat exchanger (203); the second output end of the third heat exchanger (203) is connected to the input end of the second cold storage filled bed (206); the output end of the second cold storage filled bed (206) is connected to the second input end of the second heat exchanger (202); the second output end of the second heat exchanger (202) is connected to the third cold storage filled bed (207). The output end of the third cold storage filled bed (207) is connected to the second input end of the first heat exchanger (201); the second output end of the first heat exchanger (201) is connected to the input end of the fourth cold storage filled bed (208); the output end of the fourth cold storage filled bed (208) is connected to the input end of the fifth cold storage filled bed (209); the output end of the fifth cold storage filled bed (209) is connected to the input end of the sixth cold storage filled bed (2010); the output end of the sixth cold storage filled bed (2010) is connected to the input end of the seventh cold storage filled bed (2011); the output end of the seventh cold storage filled bed (2011) is connected to the environment as the second output end of the cold energy cascade storage and exchange unit (200).

4. The liquid air energy storage power generation device based on packed bed cascade cold storage according to claim 1 is characterized in that: The air expansion power generation unit (300) comprises a fifth heat exchanger (301), a first expansion generator (302), a sixth heat exchanger (303), a second expansion generator (304), a seventh heat exchanger (305), a third expansion generator (306), an eighth heat exchanger (307) and a fourth expansion generator (308); The input end of the fifth heat exchanger (301) is connected to the first output end of the cold energy cascade storage and exchange unit (200) as the input end of the air expansion power generation unit (300); the output end of the fifth heat exchanger (301) is connected to the input end of the first expansion generator (302); the output end of the first expansion generator (302) is connected to the input end of the sixth heat exchanger (303); the output end of the sixth heat exchanger (303) is connected to the input end of the second expansion generator (304); the output end of the second expansion generator (304) is connected to the The seventh heat exchanger (305) is connected to the input end of the seventh heat exchanger (305); the output end of the seventh heat exchanger (305) is connected to the input end of the third expansion generator (306); the output end of the third expansion generator (306) is connected to the input end of the eighth heat exchanger (307); the output end of the eighth heat exchanger (307) is connected to the input end of the fourth expansion generator (308); the output end of the fourth expansion generator (308) is connected as the output end of the air expansion power generation unit (300) to the second input end of the cold energy cascade storage and exchange unit (200).

5. A liquid air energy storage power generation method based on packed bed cascade cold storage, characterized in that: The method is implemented based on a liquid air energy storage power generation device based on packed bed cascade cold storage as described in any one of claims 1 to 4, comprising: Liquid air flows out of the liquid air storage tank (101), and is pressurized by a low-temperature pump (102) to provide circulation power. The liquid air is pumped to a first heat exchanger (201), a second heat exchanger (202), a third heat exchanger (203), and a fourth heat exchanger (204) for staged vaporization; the vaporized air enters an air expansion power generation unit (300) for multi-stage heating and expansion power generation; the expanded air with residual pressure enters a cold energy cascade storage and exchange unit (200) as a heat exchange fluid to stage-heat the liquid air and recover the vaporized cold energy to a first cold storage filling bed (205), a second cold storage filling bed (206), a third cold storage filling bed (207), a fourth cold storage filling bed (208), a fifth cold storage filling bed (209), a sixth cold storage filling bed (2010), and a seventh cold storage filling bed (2011) for staged storage; and finally the air is discharged from the seventh cold storage filling bed (2011) into the environment.

6. A liquid air energy storage power generation method based on packed bed cascade cold storage according to claim 5, characterized in that: The vaporization cold energy of liquid air is stored in a plurality of cold storage packed beds in a stepwise manner, wherein the first cold storage packed bed (205) and the seventh cold storage packed bed (2011) store low-grade cold energy, the second cold storage packed bed (206) and the sixth cold storage packed bed (2010) store medium-grade cold energy, the third cold storage packed bed (207) and the fifth cold storage packed bed (209) store medium- and high-grade cold energy, and the fourth cold storage packed bed (208) stores high-grade cold energy.

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