Device and Method for Improving the Efficiency of a Cryogenic Liquid Air Energy Storage System

Abstract

The present invention provides a device and method for improving the efficiency of a cryogenic liquid air energy storage system. The device includes a liquid air energy storage subsystem and a Kalina cycle power generation subsystem; wherein, the liquid air energy storage subsystem includes an energy storage unit, a heat storage tank, a cold energy storage tank and an energy release unit; the cold energy storage tank is adapted to exchange heat with the energy storage unit and the energy release unit; the heat storage tank is adapted to exchange heat with the energy storage unit, the energy release unit and the Kalina cycle power generation subsystem. By setting up the energy storage unit, the heat storage tank, the cold energy storage tank and the energy release unit, the efficient storage and release of heat are realized; by setting up the heat storage tank to exchange heat with the energy storage unit, the energy release unit and the Kalina cycle power generation subsystem, the compression heat collected during the compression process is not only used to heat the air temperature at the inlet of the air turbine, but also used to drive the Kalina cycle power generation subsystem to generate electricity, improving the energy storage efficiency of the entire system. The efficiency of the combined power generation system proposed by the present invention can be increased by 5-10 percentage points.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy, and particularly to a device and method for improving the efficiency of a cryogenic liquid air energy storage system. Background Art

[0002] Large-scale energy storage technology has very important applications in the efficient utilization of renewable energy and peak shaving and valley filling of power grids. At present, pumped-storage energy storage and compressed air energy storage are relatively mature in large-scale energy storage technologies. However, the construction of pumped-storage energy storage is restricted by geographical conditions, and compressed air energy storage also has problems such as high cost of small-scale gas storage and geographical conditions restrictions for large-scale gas storage. Therefore, liquid air energy storage, as a new large-scale energy storage technology, has very broad application prospects. Compared with other large-scale energy storage technologies, liquid air energy storage has two obvious advantages: one is that air is stored in a liquid state at normal pressure with a high energy storage density; the other is that the volume of the liquid air storage tank is relatively small, and the location of the liquid air energy storage power station is not restricted by geographical conditions.

[0003] In the current liquid air energy storage system, the liquefaction rate of air is generally about 0.6 - 0.85, that is, the mass flow rate of air participating in the compression process and the mass flow rate of air participating in the expansion power generation process are not equal. There is a large amount of surplus compression heat, which greatly affects the efficiency of the liquid air energy storage system. Summary of the Invention

[0004] The present invention provides a device and method for improving the efficiency of a cryogenic liquid air energy storage system, so as to solve the defects of surplus compression heat and low system efficiency in the prior art, and realize more sufficient utilization of compression heat.

[0005] The present invention provides a device for improving the efficiency of a cryogenic liquid air energy storage system, including a liquid air energy storage subsystem and a Kalina cycle power generation subsystem; wherein, the liquid air energy storage subsystem includes an energy storage unit, a heat storage tank, a cold storage tank and an energy release unit; the cold storage tank is adapted to exchange heat with the energy storage unit and the energy release unit; the heat storage tank is adapted to exchange heat with the energy storage unit, the energy release unit and the Kalina cycle power generation subsystem.

[0006] According to the device for improving the efficiency of a cryogenic liquid air energy storage system provided by the present invention, the liquid air energy storage subsystem further includes a liquid air storage tank and a liquid air pump, and the liquid air storage tank and the liquid air pump are arranged between the energy storage unit and the energy release unit.

[0007] According to the device for improving the efficiency of a cryogenic liquid air energy storage system provided by the present invention, the energy storage unit includes an air compressor, a first heat exchanger and a second heat exchanger, the heat storage tank is adapted to exchange heat with the first heat exchanger, and the cold storage tank is adapted to exchange heat with the second heat exchanger.

[0008] A device for improving the efficiency of a cryogenic liquid air energy storage system according to the present invention, the liquid air energy storage subsystem further includes a throttle valve and a separator, the throttle valve and the separator are arranged downstream of the second heat exchanger, and the separator is adapted to return the separated gaseous air to the second heat exchanger.

[0009] A device for improving the efficiency of a cryogenic liquid air energy storage system according to the present invention, the energy release unit includes a third heat exchanger, a fourth heat exchanger and an air turbine, the heat storage tank is adapted to exchange heat with the fourth heat exchanger, and the cold storage tank is adapted to exchange heat with the third heat exchanger.

[0010] A device for improving the efficiency of a cryogenic liquid air energy storage system according to the present invention, the Kalina cycle power generation subsystem includes an evaporator, a rectification column, a Kalina turbine, an absorber, a condenser, an ammonia water pump and a preheater connected in sequence; the rectification column is also connected to the preheater, and the absorber is also connected to the preheater.

[0011] The present invention also provides a method based on the device for improving the efficiency of a cryogenic liquid air energy storage system as described above, including:

[0012] Energy storage stage: Compressed air flows through the energy storage unit, the heat storage medium in the energy storage unit cools the compressed air to room temperature, and the cold storage medium in the energy storage unit further cools and liquefies the compressed air.

[0013] Energy release stage: The heat storage medium is divided into two parts, one part enters the energy release unit, and the other part enters the Kalina cycle power generation subsystem; the cold storage medium enters the energy release unit to absorb the cold of the liquid air to make it reach room temperature.

[0014] A method for improving the efficiency of a cryogenic liquid air energy storage system according to the present invention, the energy storage stage includes: Compressed air flows through the first heat exchanger and is cooled to room temperature by the heat storage medium, and the room temperature compressed air enters the second heat exchanger and is further cooled and liquefied by the cold storage medium.

[0015] A method for improving the efficiency of a cryogenic liquid air energy storage system according to the present invention, the energy release stage includes: The heat storage medium is divided into two parts, one part enters the fourth heat exchanger to heat the air, and the other part enters the evaporator of the Kalina cycle power generation subsystem to heat the ammonia water; the cold storage medium absorbs the cold of the liquid air in the third heat exchanger to make it reach room temperature.

[0016] A method for improving the efficiency of a cryogenic liquid air energy storage system according to the present invention, the heat storage medium is contained in a heat storage tank, and the cold storage medium is contained in a cold storage tank.

[0017] The device for improving the efficiency of a cryogenic liquid air energy storage system provided by the present invention realizes the efficient storage and release of heat by setting up an energy storage unit, a heat storage tank, a cold storage tank, and an energy release unit. By arranging heat exchange between the heat storage tank and the energy storage unit, the energy release unit, and the Kalina cycle power generation subsystem, the compression heat collected during the compression process is not only used to heat the air at the inlet of the air turbine but also used to drive the Kalina cycle power generation subsystem to generate electricity, thereby improving the energy storage efficiency of the entire system. The efficiency of the combined power generation system proposed by the present invention can be increased by 5 - 10 percentage points. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0019] Figure 1 is a schematic structural diagram of the device for improving the efficiency of a cryogenic liquid air energy storage system provided by the present invention;

[0020] Figure 2 is a schematic structural diagram of the electronic device provided by the present invention.

[0021] Reference numerals:

[0022] 1, air compressor; 2, first heat exchanger; 3, second heat exchanger; 4, throttle valve; 5, separator; 6, liquid air storage tank; 7, liquid air pump; 8, third heat exchanger; 9, fourth heat exchanger; 10, air turbine; 11, cold storage tank; 12, heat storage tank; 13, evaporator; 14, rectification column; 15, Kalina turbine; 16, absorber; 17, condenser; 18, ammonia water pump; 19, preheater; 810, processor; 820, communication interface; 830, memory; 840, communication bus. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] To make the objectives, technical solutions, and advantages of the present invention clearer, the following will clearly and completely describe the technical solutions in the present invention with reference to the accompanying drawings in the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art without creative efforts based on the embodiments in the present invention belong to the scope of protection of the present invention.

[0024] The following will describe Figure 1 the device for improving the efficiency of a cryogenic liquid air energy storage system of the present invention.

[0025] An embodiment of the present invention provides a device for improving the efficiency of a cryogenic liquid air energy storage system, which includes a liquid air energy storage subsystem and a Kalina cycle power generation subsystem; wherein, the liquid air energy storage subsystem includes an energy storage unit, a heat storage tank 12, a cold energy storage tank 11, and an energy release unit; the cold energy storage tank 11 is adapted to exchange heat with the energy storage unit and the energy release unit; the heat storage tank 12 is adapted to exchange heat with the energy storage unit, the energy release unit, and the Kalina cycle power generation subsystem.

[0026] The device for improving the efficiency of the cryogenic liquid air energy storage system provided by the embodiment of the present invention realizes the efficient storage and release of heat by setting an energy storage unit, a heat storage tank 12, a cold energy storage tank 11, and an energy release unit; by setting the heat storage tank 12 to exchange heat with the energy storage unit, the energy release unit, and the Kalina cycle power generation subsystem, the compression heat collected during the compression process is not only used to heat the air at the inlet of the air turbine 10, but also used to drive the Kalina cycle power generation subsystem to generate electricity, improving the energy storage efficiency of the entire system. The efficiency of the combined power generation system proposed by the present invention can be increased by 5-10 percentage points.

[0027] First, the liquid air energy storage subsystem provided in this embodiment will be described below. Specifically, the liquid air energy storage subsystem provided in this embodiment includes an energy storage unit, a heat storage tank 12, a cold energy storage tank 11, and an energy release unit.

[0028] The energy storage unit is mainly used to store the compression heat generated during the air compression process in the heat storage tank 12 and complete the utilization of cold energy. As Figure 1 shown, in this embodiment, the energy storage unit includes an air compressor 1, a first heat exchanger 2, and a second heat exchanger 3.

[0029] The air compressor 1 is used to compress air, and the compressed air is in a high-temperature and high-pressure state. Optionally, before compressing the air, the air can be purified first to obtain a better compression effect, and at the same time prevent impurities in the air from entering the device, avoiding the possibility of damaging the device.

[0030] The first heat exchanger 2 is used to realize heat exchange between the heat storage tank 12 and the high-temperature and high-pressure air. The first heat exchanger 2 can be a floating head heat exchanger, or a shell-and-tube heat exchanger, a double-pipe heat exchanger, a plate heat exchanger, etc. The specific type of the first heat exchanger 2 is not limited here, as long as it can play the role of realizing heat exchange between the heat storage tank 12 and the high-temperature and high-pressure air. When the high-temperature and high-pressure air flows through the first heat exchanger 2, it is cooled to room temperature by the heat storage medium flowing therein. It is worth mentioning that the heat storage medium can be stored in the heat storage tank 12. That is to say, during this process, the storage of compression heat is completed.

[0031] The second heat exchanger 3 is used to realize the heat exchange between the cold energy storage tank 11 and the normal-temperature high-pressure air after heat exchange in the first heat exchanger 2. The second heat exchanger 3 can also be selected from one of the heat exchangers such as floating head type, shell and tube type, double pipe type, plate type, etc. The normal-temperature high-pressure air enters the second heat exchanger 3 and is further cooled and liquefied by the cold storage medium flowing therein, becoming high-pressure liquid air. It is worth mentioning that the cold energy in the cold storage medium comes from the cold energy collected by the energy release unit. That is to say, in this process, the utilization of cold energy is completed.

[0032] Optionally, downstream of the energy storage unit, a throttle valve 4 and a separator 5 can also be provided, as Figure 1 shown. The throttle valve 4 is used for pressure reduction and can change the liquid air into a gas-liquid mixture, while the separator 5 is suitable for separating the gas and liquid in the gas-liquid mixture. It can be understood that the high-pressure liquid air flowing out of the second heat exchanger 3 becomes a gas-liquid mixture after being depressurized by the throttle valve 4 and then enters the gas-liquid separator 5, where it is separated into liquid air and low-temperature gaseous air. A pipeline for returning to the second heat exchanger 3 is provided at the upper part of the separator 5. By setting it in this way, the separated gaseous low-temperature air can be returned to the second heat exchanger 3, thereby providing part of the cold energy for cooling the high-pressure air and increasing the efficiency of cold energy utilization. The separated liquid air flows out from the pipeline provided at the lower part of the separator 5 and enters the energy release unit.

[0033] As Figure 1 shown, in the device for improving the efficiency of the cryogenic liquid air energy storage system provided by the embodiment of the present invention, a liquid air storage tank 6 and a liquid air pump 7 are further included in the liquid air energy storage subsystem, which are arranged between the energy storage unit and the energy release unit. The liquid air storage tank 6 is used for storing the liquid air after heat exchange in the energy storage unit. In other words, the liquid air separated by the separator 5 enters the liquid air storage tank 6 for storage. Such a setting can realize the storage of liquid air, which is beneficial to adaptively release energy according to needs. The liquid air pump 7 is used for pressurizing the liquid air to make it high-pressure liquid air and then enter the energy release unit.

[0034] The energy release unit is mainly used to complete the storage of cold energy and release the compressed heat stored in the heat storage medium to do work. As Figure 1 shown, in this embodiment, the energy release unit includes a third heat exchanger 8, a fourth heat exchanger 9 and an air turbine 10.

[0035] The third heat exchanger 8 is used to realize the heat exchange between the high-pressure liquid air and the cold energy storage tank 11. The high-pressure liquid air flowing out of the energy storage unit flows into the third heat exchanger 8. In the embodiment provided with the liquid air storage tank 6 and the liquid air pump 7, as Figure 1As shown, high-pressure liquid air flows out of the liquid air pump 7 and enters the third heat exchanger 8. In the third heat exchanger 8, the cold storage medium absorbs the cold energy in the liquid air and brings it to room temperature. It is worth noting that the cold storage medium can be stored in the cold energy storage tank 11. That is to say, during this process, the storage of cold energy is completed.

[0036] The room-temperature high-pressure air cooled by the third heat exchanger 8 flows into the fourth heat exchanger 9. The heat storage medium in the fourth heat exchanger 9 heats the room-temperature high-pressure air to increase the temperature of the inlet air entering the air turbine 10, thereby increasing the power generation of the air turbine 10.

[0037] It should be noted that the heat storage medium in the heat storage tank 12 is divided into two parts. One part enters the fourth heat exchanger 9 to heat the air as described above. The other part enters the Kalina cycle power generation subsystem to drive the Kalina cycle power generation subsystem to generate electricity.

[0038] The air turbine 10 is a machine used to convert the energy contained in high-temperature and high-pressure air into mechanical work. The room-temperature high-pressure air is heated to a high temperature in the fourth heat exchanger 9 and then enters the air turbine 10 to expand and do work, driving the air turbine 10 to rotate and generate electricity.

[0039] The liquid air energy storage subsystem provided in this embodiment further includes a cold energy storage tank 11. The cold energy storage tank 11 contains a cold storage medium, which can be water or other refrigerants. The cold storage medium absorbs the cold energy in the liquid air in the third heat exchanger 8 to bring it to room temperature, completing the storage of cold energy; in the second heat exchanger 3, the room-temperature high-pressure air is further cooled and liquefied into high-pressure liquid air, completing the utilization of cold energy.

[0040] The liquid air energy storage subsystem provided in this embodiment further includes a heat storage tank 12. The heat storage tank 12 contains a heat storage medium, which can be water or other fluid media with good thermal conductivity. The heat storage medium absorbs the heat of the high-temperature and high-pressure air in the first heat exchanger 2 to cool it to room temperature, completing the storage of compression heat; a part of the heat storage medium enters the fourth heat exchanger 9 to increase the temperature of the inlet air entering the air turbine 10 to increase the power generation of the air turbine 10, and another part of the heat storage medium enters the evaporator 13 in the Kalina cycle power generation subsystem to drive the Kalina cycle power generation subsystem to generate electricity, completing the utilization of thermal energy. By setting it in this way, the energy storage utilization efficiency of the entire system is improved.

[0041] The Kalina cycle power generation subsystem provided in this embodiment will be described below. The Kalina cycle power generation subsystem includes an evaporator 13, a rectifying column 14, a Kalina turbine 15, an absorber 16, a condenser 17, an ammonia water pump 18, and a preheater 19. Among them, the evaporator 13, the rectifying column 14, the Kalina turbine 15, the absorber 16, the condenser 17, the ammonia water pump 18, and the preheater 19 are connected in sequence. The rectifying column 14 is also connected to the preheater 19, and the absorber 16 is also connected to the preheater 19. That is to say, the rectifying column 14 is respectively connected to the evaporator 13, the preheater 19, and the Kalina turbine 15, and the absorber 16 is respectively connected to the Kalina turbine 15, the preheater 19, and the condenser 17.

[0042] In the Kalina cycle power generation system, the low-temperature liquid ammonia water is pressurized by the ammonia water pump 18 and then enters the preheater 19, where it is preheated by the low-concentration ammonia water and then enters the evaporator 13. In the evaporator 13, the liquid ammonia water is heated by a part of the heat storage medium flowing out of the heat storage tank 12 to become a gas-liquid mixture, and then enters the rectifier. In the rectifier, the gas-liquid mixture is separated, the low-concentration ammonia water flows back to the preheater 19 to heat the low-temperature liquid ammonia water, and the high-concentration ammonia gas enters the Kalina turbine 15 to expand and do work to generate electricity. The low-concentration ammonia water flowing out of the preheater 19 and the high-concentration ammonia gas after expansion are mixed in the absorber 16 to become a gas-liquid mixture, which is condensed by cooling water in the condenser 17 and enters the next cycle.

[0043] The present invention also provides a method for a device based on the above-mentioned method for improving the efficiency of a cryogenic liquid air energy storage system, including:

[0044] Energy storage stage: Compressed air flows through the energy storage unit, the heat storage medium in the energy storage unit cools the compressed air to room temperature, and the cold storage medium in the energy storage unit further cools and liquefies the compressed air.

[0045] Energy release stage: The heat storage medium is divided into two parts, one part enters the energy release unit, and the other part enters the Kalina cycle power generation subsystem; the cold storage medium enters the energy release unit to absorb the cold of the liquid air to bring it to room temperature.

[0046] That is to say, in the energy storage stage, the compressed air flows through the energy storage unit, and the heat storage medium and the cold storage medium absorb the heat of the compressed air to cool and liquefy the compressed air. In the energy release stage, the heat storage medium enters the energy release unit and the Kalina cycle power generation subsystem respectively to release heat, so that the energy release unit and the Kalina cycle power generation subsystem work to generate electricity simultaneously.

[0047] Combined with Figure 1, specifically, during the energy storage stage, the compressed air flows through the first heat exchanger 2 and is cooled to room temperature by the heat storage medium, which stores the compression heat; the room-temperature compressed air enters the second heat exchanger 3 and is further cooled and liquefied by the cold carried by the cold storage medium. During the energy release stage, the heat storage medium is divided into two parts. One part enters the fourth heat exchanger 9 to heat the air, and the other part enters the evaporator 13 of the Kalina cycle power generation subsystem to heat the ammonia water, releasing the stored heat; the cold storage medium absorbs the cold of the liquid air in the third heat exchanger 8 to bring it to room temperature.

[0048] Figure 2 An example of a schematic diagram of the physical structure of an electronic device is shown as Figure 2 shown. The electronic device may include: a processor 810, a communication interface 820, a memory 830, and a communication bus 840. Among them, the processor 810, the communication interface 820, and the memory 830 communicate with each other through the communication bus 840. The processor 810 can call the logical instructions in the memory 830 to execute the method of the device for improving the efficiency of the cryogenic liquid air energy storage system as described above. The method includes:

[0049] Energy storage stage: The compressed air flows through the energy storage unit, and the heat storage medium in the energy storage unit cools the compressed air to room temperature, and the cold storage medium in the energy storage unit further cools and liquefies the compressed air;

[0050] Energy release stage: The heat storage medium is divided into two parts. One part enters the energy release unit, and the other part enters the Kalina cycle power generation subsystem; the cold storage medium enters the energy release unit to absorb the cold of the liquid air to bring it to room temperature.

[0051] In addition, when the logical instructions in the above-mentioned memory 830 are implemented in the form of software functional units and sold or used as an independent product, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of this technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of the present invention. The foregoing storage medium includes: USB flash drives, mobile hard disks, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), magnetic disks, or optical discs, etc., which can store program codes.

[0052] On the other hand, the present invention also provides a computer program product, which includes a computer program that can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the method of the device for improving the efficiency of a cryogenic liquid air energy storage system as described above. The method includes:

[0053] Energy storage stage: Compressed air flows through the energy storage unit. The heat storage medium in the energy storage unit cools the compressed air to room temperature, and the cold storage medium in the energy storage unit further cools and liquefies the compressed air;

[0054] Energy release stage: The heat storage medium is divided into two parts. One part enters the energy release unit, and the other part enters the Kalina cycle power generation subsystem; the cold storage medium enters the energy release unit to absorb the cold of the liquid air to bring it to room temperature.

[0055] In another aspect, the present invention also provides a non-transitory computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it realizes the method of the device for improving the efficiency of a cryogenic liquid air energy storage system as described above. The method includes:

[0056] Energy storage stage: Compressed air flows through the energy storage unit. The heat storage medium in the energy storage unit cools the compressed air to room temperature, and the cold storage medium in the energy storage unit further cools and liquefies the compressed air;

[0057] Energy release stage: The heat storage medium is divided into two parts. One part enters the energy release unit, and the other part enters the Kalina cycle power generation subsystem; the cold storage medium enters the energy release unit to absorb the cold of the liquid air to bring it to room temperature.

[0058] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated. The components shown as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art can understand and implement it without creative efforts.

[0059] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on such an understanding, the essence of the above technical solution, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to enable a computer device (which can be a personal computer, server, or network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An apparatus for improving the efficiency of a cryogenic liquid air energy storage system, characterized in that It includes a liquid air energy storage subsystem and a Kalina cycle power generation subsystem; wherein, the liquid air energy storage subsystem includes an energy storage unit, a heat storage tank, a cold storage tank and an energy release unit; the cold storage tank is adapted to exchange heat with the energy storage unit and the energy release unit; the heat storage tank is adapted to exchange heat with the energy storage unit, the energy release unit and the Kalina cycle power generation subsystem; The liquid air energy storage subsystem further includes a liquid air storage tank and a liquid air pump, and the liquid air storage tank and the liquid air pump are arranged between the energy storage unit and the energy release unit; The energy storage unit includes an air compressor, a first heat exchanger and a second heat exchanger, the heat storage tank is adapted to exchange heat with the first heat exchanger, and the cold storage tank is adapted to exchange heat with the second heat exchanger; The liquid air energy storage subsystem further includes a throttle valve and a separator, the throttle valve and the separator are arranged downstream of the second heat exchanger, and the separator is adapted to return the separated gaseous air to the second heat exchanger; The energy release unit includes a third heat exchanger, a fourth heat exchanger and an air turbine, the heat storage tank is adapted to exchange heat with the fourth heat exchanger, and the cold storage tank is adapted to exchange heat with the third heat exchanger; The Kalina cycle power generation subsystem includes an evaporator, a rectification column, a Kalina turbine, an absorber, a condenser, an ammonia water pump and a preheater connected in sequence; the rectification column is further connected to the preheater, and the absorber is further connected to the preheater.

2. A method for improving the efficiency of a cryogenic liquid air energy storage system, based on the device for improving the efficiency of a cryogenic liquid air energy storage system as described in claim 1, characterized in that, It includes: Energy storage stage: Compressed air flows through the energy storage unit, and the heat storage medium in the energy storage unit cools the compressed air to normal temperature state, and the cold storage medium in the energy storage unit further cools and liquefies the compressed air; Energy release stage: The heat storage medium is divided into two parts, one part enters the energy release unit, and the other part enters the Kalina cycle power generation subsystem; the cold storage medium enters the energy release unit to absorb the cold of the liquid air to make it reach the normal temperature state.

3. The method for improving the efficiency of a cryogenic liquid air energy storage system according to claim 2, characterized in that The energy storage stage includes: Compressed air flows through the first heat exchanger and is cooled to normal temperature state by the heat storage medium, and the normal temperature compressed air enters the second heat exchanger and is further cooled and liquefied by the cold storage medium.

4. The method for improving the efficiency of a cryogenic liquid air energy storage system according to claim 2, wherein The energy release stage includes: The heat storage medium is divided into two parts, one part enters the fourth heat exchanger to heat the air, and the other part enters the evaporator of the Kalina cycle power generation subsystem to heat the ammonia water; the cold storage medium absorbs the cold of the liquid air in the third heat exchanger to make it reach the normal temperature state.

5. The method for improving the efficiency of a cryogenic liquid air energy storage system according to claim 2, wherein, The heat storage medium is contained in the heat storage tank, and the cold storage medium is contained in the cold storage tank.

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