Segmented shared heat exchange method and system for liquid air energy storage power station

Abstract

The invention discloses a segmented shared heat exchange method and system for a liquid air energy storage power station, belongs to the technical field of liquid air energy storage, and aims to solve the problems of complexity, low efficiency and high cost of a heat exchange system in the prior art. The system comprises a compression unit, a heat exchange and storage unit, a liquefaction unit, an expansion unit and a liquid air storage unit. The compression unit compresses normal-temperature and normal-pressure air step by step, and output air sequentially passes through the first-stage shared heat exchanger, the first-stage shared heat storage tank and the first-stage cooler to be cooled. The heat exchange and storage unit stores heat in the compression stage, releases heat in the expansion stage and is connected with the compression unit and the expansion unit through a fluid pipeline. The liquefying unit liquefies high-pressure air through an LNG heat exchanger, and liquid air is stored in a liquid air storage tank through a gas-liquid separator. The expansion unit releases energy through liquid air expansion acting, and air enters an expansion machine after being preheated to complete energy conversion and then is discharged into the environment. The method is suitable for improving the energy storage efficiency of renewable energy sources and power peak regulation work.

Description

Technical Field

[0001] The invention relates to the technical field of liquid air energy storage, and in particular to segmented shared heat exchange in a liquid air energy storage power station. Background Art

[0002] Liquid Air Energy Storage (LAES) technology, as a new type of energy storage method, has important application prospects in solving the volatility and intermittent problems of renewable energy. The technology compresses air into liquid and stores it, and releases energy through expansion when needed to drive the generator to generate electricity. Liquid air energy storage technology has high energy density and long-term energy storage capacity, so it has broad application potential in fields such as power peak regulation and backup power supply.

[0003] With the transformation of the global energy structure and the increase in the proportion of renewable energy, liquid air energy storage has attracted much attention as an efficient and clean energy storage technology. Compared with traditional energy storage methods such as chemical batteries and pumped storage, liquid air energy storage has many advantages. For example, it does not need to rely on scarce resources, there is no harmful emission during the energy conversion process, and it is suitable for large-scale industrial applications.

[0004] In the past few decades, liquid air energy storage technology has undergone a transformation from laboratory research to practical engineering applications. Scholars and engineers have proposed a variety of liquid air energy storage system designs, optimized the efficiency of compression and expansion, and explored low-temperature energy recovery technology. For example, some studies focus on improving the energy efficiency of compressors and expanders, using efficient heat exchangers to reduce heat losses, and reducing overall energy consumption by optimizing the layout and process of the system.

[0005] However, existing liquid air energy storage technology still faces some technical challenges, especially in heat exchange and thermal energy management. A key issue in liquid air energy storage systems is how to effectively utilize the high-temperature heat released during the compression phase and recover this heat during the expansion phase. Due to the large temperature difference between the compression process and the expansion process, existing technologies usually have certain limitations in the design of heat exchange equipment. For example, heat exchange systems often require complex piping and equipment layouts, which leads to larger system costs and footprint.

[0006] However, the utilization rate of the liquid air energy storage system in the existing technology is low in the heat exchange stage, which is mainly manifested in the following aspects:

[0007] Complexity of heat exchange system: Existing heat exchange systems often require multiple heat exchangers and heat accumulators to handle the heat exchange during compression and expansion respectively, which not only increases the number of equipment but also increases the system's footprint.

[0008] Low heat exchange efficiency: Due to the large difference in temperature parameters between the compression stage and the expansion stage, the heat exchanger design in the existing technology is difficult to achieve efficient heat recovery and conversion, resulting in insufficient energy utilization.

[0009] High system cost: The complex heat exchange equipment and pipeline layout make the initial investment of existing liquid air energy storage systems high, reducing the feasibility of their commercial application. Summary of the invention

[0010] In order to solve the problems existing in the prior art, that is, the heat exchange system is complex, inefficient and costly, the technical solution provided by the present invention is:

[0011] A segmented shared heat exchange system for a liquid air energy storage power station.

[0012] The system includes a compression unit, a heat exchange and thermal storage unit, a liquefaction unit, an expansion unit, and a liquid air storage unit;

[0013] The compression unit is used to compress the air at normal temperature and pressure step by step, and the output end of the compression unit is connected to the primary common heat exchanger, the primary common heat storage tank and the primary cooler of the heat exchange and heat storage unit in sequence;

[0014] The heat exchange and heat storage unit is used to store compression heat in the compression stage and release heat in the expansion stage, and the heat exchange and heat storage unit is connected to the compression unit and the expansion unit through a fluid pipeline;

[0015] The liquefaction unit is used to liquefy the high-pressure air cooled by the heat exchange and heat storage unit, and the liquefied air is separated by the gas-liquid separator and then enters the liquid air storage unit;

[0016] The liquid air storage unit is used to store liquefied liquid air, and the liquid air storage unit includes a liquid air storage tank, and the liquid air storage tank is connected to the expansion unit;

[0017] The expansion unit is used to utilize liquid air to expand and do work and release energy, and the inlet of the expansion unit is connected to the liquid air storage unit through a primary preheater, a secondary preheater, a secondary common heat storage tank and a secondary common heat exchanger;

[0018] The units of the system are interconnected through fluid pipelines, and the output air of the compression unit passes through the heat exchange and heat storage unit, the liquefaction unit, and the liquid air storage unit in sequence, and completes energy release through the expansion unit.

[0019] Further, a preferred embodiment is provided, wherein the compression unit comprises a primary compressor and a secondary compressor.

[0020] Further, a preferred embodiment is provided, wherein the heat exchange and heat storage unit includes a primary common heat exchanger, a secondary common heat exchanger, a primary common heat storage tank, a secondary common heat storage tank, a primary cooler, a secondary cooler, a tertiary cooler, a quaternary cooler, a primary preheater, a secondary preheater, a high-temperature hot water tank, a high-temperature cold water tank, a low-temperature hot water tank and a low-temperature cold water tank.

[0021] Furthermore, a preferred embodiment is provided, wherein the liquefaction unit comprises an LNG heat exchanger, a liquid expander and a gas-liquid separator, and the LNG heat exchanger realizes air liquefaction through a first cold source and a second cold source.

[0022] Furthermore, a preferred embodiment is provided, wherein the expansion unit comprises a primary expander and a secondary expander, and the expander is connected to a primary generator and a secondary generator.

[0023] Based on the same inventive concept, the present invention also provides a liquid air energy storage power station, which includes the system.

[0024] Based on the same inventive concept, the present invention also provides a segmented shared heat exchange method for a liquid air energy storage power station, which is implemented based on the system described above and includes:

[0025] The step of collecting the temperature and pressure of the air at the outlet of the compression unit, and sending instructions for controlling the valve switching of the heat exchange and thermal storage unit and the operation of the cooler according to the data;

[0026] The step of determining the liquefaction condition of the air according to its temperature and pressure, and sending an instruction to store the liquid air in a liquid air storage tank;

[0027] The steps of detecting the state of air in the liquid air storage tank, sending instructions to control the operation of the pump, the preheater and the heat exchanger, and allowing the air to enter the expansion unit after being heated to complete expansion work;

[0028] The step of monitoring the water temperature of the cold water tank and sending instructions to adjust the circulation between the cooler and the water tank.

[0029] Based on the same inventive concept, the present invention also provides a computer storage medium for storing a computer program. When the computer program is read by a computer, the computer executes the described method.

[0030] Based on the same inventive concept, the present invention also provides a computer, including a processor and a storage medium. When the processor reads a computer program stored in the storage medium, the computer executes the method described.

[0031] Based on the same inventive concept, the present invention also provides a computer program product, which is a computer program. When the computer program is executed, the method described above is implemented.

[0032] Compared with the prior art, the technical solution provided by the present invention is beneficial in that:

[0033] By adopting the design of segmented shared heat exchangers and shared heat storage tanks, the heat exchange system of the liquid air energy storage power station is effectively simplified. The shared configuration of the first-level shared heat exchanger and the second-level shared heat exchanger replaces the practice of configuring separate heat exchangers for the compression stage and the expansion stage in the traditional system. This design not only reduces the number of heat exchange equipment, but also significantly reduces the initial investment cost and equipment footprint of the system, solving the problems of many heat exchangers, large footprint and high cost in the existing technology. Compared with the traditional liquid air energy storage system, the heat exchange efficiency of this solution has been greatly improved, and the requirements for equipment and floor space have also been reduced.

[0034] By introducing a shared heat storage tank, this solution effectively solves the problem of compression heat storage and utilization. The heat generated during the compression process is no longer discharged separately, but is stored in a heat storage tank for use in the expansion stage. This heat storage method is simpler and more stable than the traditional system in which multiple devices operate simultaneously. The heat storage tank has a simpler structure than the heat exchanger and has higher operating stability, further reducing the complexity and cost of the system. Compared with the prior art method of achieving heat recovery through multiple heat exchangers, the heat storage tank has higher efficiency and stability in storing and releasing heat.

[0035] The present invention uses a low-temperature hot water tank to store low-grade compression heat and uses it to heat the outlet air of the first-stage preheater, making its temperature closer to the outlet air temperature of the expander. This design solves the problem of inconsistent temperatures between the compression and expansion stages in traditional systems and improves the efficiency of heat utilization. Compared with the direct heat exchange method in traditional heat exchangers, this temperature control design not only improves the heat exchange efficiency of the system, but also enables the system to maintain a stable working state when facing different loads, thereby improving overall performance.

[0036] In addition, the cold air circulation design of the LNG heat exchanger optimizes the cooling process by cooling the excess compression heat. The cold air at the outlet of the LNG heat exchanger is used to reduce the water temperature of the cold tank, forming a water cycle, thereby improving the cooling efficiency. Compared with the traditional technology that simply relies on the environment or external cold source for cooling, the internal circulation cooling method of the LNG heat exchanger can more effectively utilize the cold generated inside the system, thereby further improving the overall energy efficiency and energy saving effect of the system.

[0037] In summary, the present invention not only simplifies the equipment structure and reduces the cost by optimizing the configuration of the heat exchanger, heat storage tank and preheater, but also improves the heat recovery rate and reduces the temperature difference between the compression and expansion stages, making the operation of the liquid air energy storage power station more efficient and stable. These designs have significant economic and technical advantages compared to the complex heat exchange system and multi-stage heat distribution method in the prior art.

[0038] It is suitable for improving the energy storage efficiency of renewable energy and power peak regulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a schematic diagram of the overall structure of the segmented shared heat exchange system of the liquid air energy storage power station.

[0040] Figure 2 This is a schematic diagram of the compression stage structure of the segmented shared heat exchange system of the liquid air energy storage power station.

[0041] Figure 3 This is a schematic diagram of the expansion stage structure of the segmented shared heat exchange system of the liquid air energy storage power station.

[0042] Among them, 1 is a primary compressor, 2 is a secondary compressor, 24 is a primary motor, 26 is a secondary motor; 3 is a primary expander, 4 is a secondary expander, 25 is a primary generator, 27 is a secondary generator; 5 is a primary common heat exchanger, 6 is a secondary common heat exchanger, 7 is a primary common heat storage tank, 8 is a secondary common heat storage tank, 9 is a primary cooler, 10 is a secondary cooler, 16 is a primary preheater, 17 is a secondary preheater, 18 is a tertiary cooler, 19 is a quaternary cooler, 20 is a high-temperature hot water tank, 21 is a high-temperature cold water tank, 22 is a low-temperature hot water tank, and 23 is a low-temperature cold water tank; 11 is an LNG heat exchanger, 12 is a liquid expander, 13 is a gas-liquid separator, and 15 is a pump; 14 is a liquid air storage tank; 100 is the compressor inlet air, 200 is the expander outlet air, 300 is the first cold source of the LNG heat exchanger, and 400 is the second cold source of the LNG heat exchanger. DETAILED DESCRIPTION

[0043] In order to make the advantages and benefits of the technical solution provided by the present invention more clearly reflected, the technical solution provided by the present invention is now further described in detail with reference to the accompanying drawings, specifically:

[0044] Embodiment 1: This embodiment provides a segmented shared heat exchange system for a liquid air energy storage power station.

[0045] The system includes a compression unit, a heat exchange and thermal storage unit, a liquefaction unit, an expansion unit, and a liquid air storage unit;

[0046] The compression unit is used to compress the air at normal temperature and pressure step by step, and the output end of the compression unit is connected to the primary common heat exchanger 5, the primary common heat storage tank 7 and the primary cooler 9 of the heat exchange and heat storage unit in sequence;

[0047] The heat exchange and heat storage unit is used to store compression heat in the compression stage and release heat in the expansion stage, and the heat exchange and heat storage unit is connected to the compression unit and the expansion unit through a fluid pipeline;

[0048] The liquefaction unit is used to liquefy the high-pressure air cooled by the heat exchange and heat storage unit, and the liquefied air is separated by the gas-liquid separator 13 and then enters the liquid air storage unit;

[0049] The liquid air storage unit is used to store liquefied liquid air, and the liquid air storage unit includes a liquid air storage tank 14, and the liquid air storage tank 14 is connected to the expansion unit;

[0050] The expansion unit is used to expand liquid air to do work and release energy. The inlet of the expansion unit is connected to the liquid air storage unit through the primary preheater 16, the secondary preheater 17, the secondary common heat storage tank 8 and the secondary common heat exchanger 6;

[0051] The units of the system are interconnected through fluid pipelines, and the output air of the compression unit passes through the heat exchange and heat storage unit, the liquefaction unit, and the liquid air storage unit in sequence, and completes energy release through the expansion unit.

[0052] Specifically,

[0053] The segmented shared heat exchange system of the liquid air energy storage power station includes:

[0054] Compression unit: includes a primary compressor 1 and a secondary compressor 2, which are driven by a primary motor 24 and a secondary motor 26 respectively.

[0055] Heat exchange and heat storage unit: includes a primary common heat exchanger 5, a secondary common heat exchanger 6, a primary common heat storage tank 7, a secondary common heat storage tank 8, a primary cooler 9, a secondary cooler 10, a tertiary cooler 18, a fourth cooler 19, a primary preheater 16, a secondary preheater 17, a high-temperature hot water tank 20, a high-temperature cold water tank 21, a low-temperature hot water tank 22, and a low-temperature cold water tank 23.

[0056] Liquefaction unit: includes LNG heat exchanger 11, liquid expander 12, gas-liquid separator 13, and pump 15.

[0057] Expansion unit: includes a primary expander 3 and a secondary expander 4, which are connected to a primary generator 25 and a secondary generator 27 respectively.

[0058] Liquid air storage unit: comprises a liquid air storage tank 14 .

[0059] Connection relationship between components

[0060] Connection between compression unit and heat exchange and thermal storage unit

[0061] Figure 2 As shown, the inlet of the first-stage compressor 1 of the compression unit is connected to the atmospheric air 100, and the outlet is connected to the first inlet of the first-stage common heat exchanger 5. After the air exchanges heat with the water in the high-temperature cold water tank 21 in the first-stage common heat exchanger, it flows into the first-stage common heat storage tank 7 from the second outlet of the first-stage common heat exchanger to store most of the compression heat. Subsequently, the air flows into the first-stage cooler 9 from the outlet of the first-stage common heat storage tank and is further cooled to the inlet design temperature of the second-stage compressor 2. The outlet of the second-stage compressor is connected to the second-stage common heat exchanger 6. After heat exchange with the water in the high-temperature cold water tank, the air flows into the second-stage common heat storage tank 8 to store the remaining compression heat, and finally enters the liquefaction unit after being cooled by the second-stage cooler 10.

[0062] Connection of liquefaction unit to liquid air storage unit

[0063] Figure 1 and Figure 2 It is shown that the cooled air is further cooled and liquefied after heat exchange with the cold sources 300 and 400 through the LNG heat exchanger 11. The liquefied air is expanded through the liquid expander 12 and then enters the gas-liquid separator 13 for separation. The liquid air is transported to the liquid air storage tank 14 for storage, and the gaseous air is cooled again by the LNG heat exchanger and enters the fourth-stage cooler 19.

[0064] Connection of liquid air storage unit to expansion unit

[0065] Figure 3 As shown, in the expansion stage, the liquid air is pressurized by the pump 15 from the liquid air storage tank 14, and then passes through the primary preheater 16 and the secondary preheater 17 in sequence, and exchanges heat with the water in the low-temperature hot water tank 22, and the temperature gradually rises to the design value. The heated air enters the secondary common heat storage tank 8, absorbs heat, and is heated again by the secondary common heat exchanger 6, and finally flows into the secondary expander 4 to expand and do work. The expanded air enters the primary common heat storage tank 7 and the primary common heat exchanger 5, and further absorbs heat and flows into the primary expander 3 to do work, completing the energy conversion in the expansion stage, and the air is finally discharged into the environment.

[0066] Internal connection relationship of heat exchange and heat storage unit

[0067] The water in the high-temperature cold water tank 21 is connected to the primary common heat exchanger 5 and the secondary common heat exchanger 6 through a pipeline, and flows into the high-temperature hot water tank 20 for storage after exchanging heat.

[0068] The water in the low-temperature cold water tank 23 flows through the primary cooler 9 and the secondary cooler 10, cools the compressed air, and then flows into the low-temperature hot water tank 22 for storage.

[0069] The cold air 400 at the outlet of the LNG heat exchanger 11 enters the tertiary cooler 18 and the quaternary cooler 19 to further exchange heat with the water in the cold water tank.

[0070] Embodiment 2: This embodiment further limits the segmented shared heat exchange system of a liquid air energy storage power station provided in Embodiment 1, and the compression unit includes a primary compressor 1 and a secondary compressor 2.

[0071] Embodiment 3. This embodiment is a further limitation of a segmented shared heat exchange system of a liquid air energy storage power station provided in embodiment 1. The heat exchange and heat storage unit includes a primary shared heat exchanger 5, a secondary shared heat exchanger 6, a primary shared heat storage tank 7, a secondary shared heat storage tank 8, a primary cooler 9, a secondary cooler 10, a tertiary cooler 18, a quaternary cooler 19, a primary preheater 16, a secondary preheater 17, a high-temperature hot water tank 20, a high-temperature cold water tank 21, a low-temperature hot water tank 22 and a low-temperature cold water tank 23.

[0072] Embodiment 4. This embodiment is a further limitation of a segmented shared heat exchange system for a liquid air energy storage power station provided in embodiment 1. The liquefaction unit includes an LNG heat exchanger 11, a liquid expansion machine 12 and a gas-liquid separator 13. The LNG heat exchanger 11 realizes air liquefaction through a first cold source and a second cold source.

[0073] Embodiment 5. This embodiment further limits the segmented shared heat exchange system of a liquid air energy storage power station provided in embodiment 1. The expansion unit includes a primary expander 3 and a secondary expander 4, and the expander is connected to a primary generator 25 and a secondary generator 27.

[0074] Embodiment 6: This embodiment provides a liquid air energy storage power station, which includes the system provided in embodiment 1.

[0075] Embodiment 7: This embodiment provides a segmented shared heat exchange method for a liquid air energy storage power station, which is implemented based on the system provided in embodiment 1 and includes:

[0076] The step of collecting the temperature and pressure of the air at the outlet of the compression unit, and sending instructions for controlling the valve switching of the heat exchange and thermal storage unit and the operation of the cooler according to the data;

[0077] The step of determining the liquefaction condition of the air according to its temperature and pressure, and sending an instruction to store the liquid air in the liquid air storage tank 14;

[0078] The steps of detecting the air state of the liquid air storage tank 14, sending instructions to control the operation of the pump 15, the preheater and the heat exchanger, and allowing the air to enter the expansion unit after being heated to complete expansion work;

[0079] The step of monitoring the water temperature of the cold water tank and sending instructions to adjust the circulation between the cooler and the water tank.

[0080] Specifically, the system operation sequence and steps are described in detail:

[0081] 1. Air compression stage

[0082] In the compression stage of the liquid air energy storage system, air at normal temperature and pressure is first compressed by the first-stage compressor 1. The first-stage compressor is driven by the first-stage motor 24. The compressed high-temperature and high-pressure air will be initially cooled by the first-stage common heat exchanger 5. The cooling process is completed by exchanging heat between the first-stage common heat exchanger and the water in the high-temperature cold water tank 21, and the cooled air flows out of the first-stage common heat exchanger.

[0083] Next, the cooled air enters the primary common heat storage tank 7, which stores most of the compression heat. This heat will be stored and used for heating in the subsequent expansion stage. The air is then further cooled by the primary cooler 9 to ensure that the air temperature reaches the inlet design temperature of the secondary compressor 2.

[0084] 2. Secondary air compression stage

[0085] The cooled air enters the secondary compressor 2, and after secondary compression, enters the secondary shared heat exchanger 6. In the heat exchanger, the compressed high-pressure air will exchange heat with the water in the high-temperature cold water tank 21, thereby further reducing the temperature of the air. The cooled air enters the secondary shared heat storage tank 8 to store the compression heat for subsequent use.

[0086] Next, the air flows into the secondary cooler 10, where the air temperature is further reduced to meet the needs of the subsequent liquefaction unit. The cooled air will enter the LNG heat exchanger 11 for cooling, during which the air exchanges heat with the cold source in the LNG heat exchanger.

[0087] 3. Liquefaction stage

[0088] In the liquefaction stage, the cooled air expands through the liquid expander 12 and absorbs heat during the expansion process. The expanded gas enters the gas-liquid separator 13 to separate the gas and liquid. The liquid air then flows into the liquid air storage tank 14 for storage and is used when needed later.

[0089] At the same time, the gaseous air cooled by the LNG heat exchanger enters the fourth-stage cooler 19, further exchanges heat with the water in the low-temperature cold water tank 23, and the air temperature is reduced to the required temperature before being discharged into the environment.

[0090] 4. Air expansion stage

[0091] During the expansion stage, the liquid air stored in the liquid air storage tank 14 is pressurized by the pump 15 and enters the primary preheater 16 and the secondary preheater 17 for heating. The heating work of the primary preheater and the secondary preheater is completed by heat exchange with the low-grade compression heat in the low-temperature hot water tank 22. This effectively increases the temperature of the liquid air to make it close to the inlet requirement of the expander.

[0092] The heated liquid air enters the secondary common heat storage tank 8, where it absorbs heat provided again by the secondary common heat exchanger 6, further raising its temperature. The heated air enters the secondary expander 4 for expansion, and the expanded air starts to do work, driving the secondary generator 27 to generate electricity.

[0093] 5. Further expansion stage

[0094] The expanded gas is further heated by the first-stage common heat storage tank 7 and the first-stage common heat exchanger 5 to increase its temperature, so as to ensure that it can effectively perform work after entering the first-stage expander 3. The expanded normal pressure air 200 is finally discharged into the environment.

[0095] 6. Circulating water cooling system

[0096] During the operation of the entire system, the cooling and heating process is achieved through the circulation of water between multiple coolers and heat storage tanks. The third-stage cooler 18 and the fourth-stage cooler 19 exchange heat with the air through cooling water flow to ensure the temperature balance in the system. The cooled water enters the high-temperature cold water tank 21 and the low-temperature cold water tank 23 for storage, providing a stable cooling cycle for the entire system.

[0097] Embodiment 8: This embodiment provides a computer storage medium for storing a computer program. When the computer program is read by a computer, the computer executes the method provided in embodiment 7.

[0098] Embodiment 9: This embodiment provides a computer, including a processor and a storage medium. When the processor reads a computer program stored in the storage medium, the computer executes the method provided in embodiment 7.

[0099] Embodiment 10: This embodiment provides a computer program product, which is a computer program. When the computer program is executed, the method provided in embodiment 7 is implemented.

[0100] Implementation Method XI: Combination Figure 1-3 This embodiment is described in detail by using specific examples to further describe the technical solution provided above. Specifically:

[0101] Figure 1 This is a schematic diagram of the overall system structure.

[0102] like Figure 2 As shown, during the compression stage of the system, air 100 is compressed by the first-stage compressor 1 and then enters the first-stage common heat exchanger 5 for partial cooling, then passes through the first-stage common heat storage tank 7 to store most of the heat in the heat storage tank, then passes through the first-stage cooler 9 to cool to the inlet design temperature of the second-stage compressor 2 and then enters the second-stage compressor 2 for compression, the compressed air enters the second-stage common heat exchanger 6 for partial cooling, then passes through the second-stage common heat storage tank 8 to store most of the heat in the heat storage tank, and then passes through the second-stage cooler 10 for cooling. The cooled high-pressure air enters the LNG heat exchanger 11 and is cooled by the air 1300 and the air 2400 and then enters the liquid expander 12 for expansion, then enters the gas-liquid separator 13 for gas-liquid separation, the liquid enters the liquid air storage tank 14 for storage, and the gas 400 enters the LNG heat exchanger 11 to cool the high-pressure air. During the process, the water in the high-temperature cold water tank 21 enters the first-level common heat exchanger 5 and the second-level common heat exchanger 6 to exchange heat with the compressed air 100 and then enters the high-temperature hot water tank 20 for storage. The water in the low-temperature cold water tank 23 enters the first-level cooler 9 and the second-level cooler 10 to cool the compressed air 100 and then enters the low-temperature hot water tank 22 for storage. Specific implementation method 2:

[0104] like Figure 3 As shown, during the expansion stage of the system, the liquid air in the liquid air storage tank 14 is pressurized by the pump 15 and enters the primary preheater 16 and the secondary preheater 17 for heating, and then enters the secondary common heat storage tank 8 to absorb heat, and then enters the secondary expander 4 to expand and work after being heated again to the inlet design temperature of the secondary expander 4 through the secondary common heat exchanger 6. The air at the expander outlet is heated by the primary common heat storage tank 7 and the primary common heat exchanger 5 and then enters the primary expander 3 to work, and then the normal pressure air 200 is discharged into the environment. In the process, the air 1300 enters the primary preheater 16 to absorb the coldness of the low-temperature air, and then enters the LNG heat exchanger 11 to cool the high-pressure air in the compression stage. The water in the low-temperature hot water tank 22 enters the secondary preheater 17 to heat the air 200, and then is further cooled by the quaternary cooler 19, and then enters the low-temperature cold water tank 23 for storage. The water in the high-temperature hot water tank 20 enters the primary common heat exchanger 5 and the secondary common heat exchanger 6 to heat the air 200, and then is further cooled by the tertiary cooler 18, and then enters the high-temperature cold water tank 21 for storage. The air 2400 after passing through the LNG heat exchanger 11 enters the tertiary cooler 18 and the quaternary cooler 19 respectively to exchange heat with water and then is discharged into the environment.

[0105] The technical solution provided by the present invention is further described in detail above through several specific implementation modes in order to highlight the advantages and benefits of the technical solution provided by the present invention. However, the several specific implementation modes described above are not intended to be used as limitations on the present invention. Any reasonable modification and improvement of the present invention, combination of implementation modes and equivalent substitution within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A segmented shared heat exchange system for a liquid air energy storage power station, characterized in that: The system includes a compression unit, a heat exchange and thermal storage unit, a liquefaction unit, an expansion unit, and a liquid air storage unit; The compression unit is used to compress the air at normal temperature and pressure step by step, and the output end of the compression unit is connected to the primary common heat exchanger, the primary common heat storage tank and the primary cooler of the heat exchange and heat storage unit in sequence; The heat exchange and heat storage unit is used to store compression heat in the compression stage and release heat in the expansion stage, and the heat exchange and heat storage unit is connected to the compression unit and the expansion unit through a fluid pipeline; The liquefaction unit is used to liquefy the high-pressure air cooled by the heat exchange and heat storage unit, and the liquefied air is separated by the gas-liquid separator and then enters the liquid air storage unit; The liquid air storage unit is used to store liquefied liquid air, and the liquid air storage unit includes a liquid air storage tank, and the liquid air storage tank is connected to the expansion unit; The expansion unit is used to utilize liquid air to expand and do work and release energy, and the inlet of the expansion unit is connected to the liquid air storage unit through a primary preheater, a secondary preheater, a secondary common heat storage tank and a secondary common heat exchanger; The units of the system are interconnected through fluid pipelines, and the output air of the compression unit passes through the heat exchange and heat storage unit, the liquefaction unit, and the liquid air storage unit in sequence, and completes energy release through the expansion unit.

2. A liquid air energy storage power station segmented shared heat exchange system according to claim 1, characterized in that: The compression unit includes a primary compressor and a secondary compressor.

3. A liquid air energy storage power station segmented shared heat exchange system according to claim 1, characterized in that: The heat exchange and heat storage unit includes a primary common heat exchanger, a secondary common heat exchanger, a primary common heat storage tank, a secondary common heat storage tank, a primary cooler, a secondary cooler, a tertiary cooler, a quaternary cooler, a primary preheater, a secondary preheater, a high-temperature hot water tank, a high-temperature cold water tank, a low-temperature hot water tank and a low-temperature cold water tank.

4. A liquid air energy storage power station segmented shared heat exchange system according to claim 1, characterized in that: The liquefaction unit comprises an LNG heat exchanger, a liquid expander and a gas-liquid separator. The LNG heat exchanger realizes air liquefaction through a first cold source and a second cold source.

5. A liquid air energy storage power station segmented shared heat exchange system according to claim 1, characterized in that: The expansion unit includes a primary expander and a secondary expander, and the expanders are connected to a primary generator and a secondary generator.

6. A liquid air energy storage power station, characterized in that: The energy storage power station comprises the system according to claim 1.

7. A segmented shared heat exchange method for a liquid air energy storage power station, characterized in that: The system according to claim 1 is implemented, comprising: The step of collecting the temperature and pressure of the air at the outlet of the compression unit, and sending instructions for controlling the valve switching of the heat exchange and thermal storage unit and the operation of the cooler according to the data; The step of determining the liquefaction condition of the air according to its temperature and pressure, and sending an instruction to store the liquid air in a liquid air storage tank; The steps of detecting the state of air in the liquid air storage tank, sending instructions to control the operation of the pump, the preheater and the heat exchanger, and allowing the air to enter the expansion unit after being heated to complete expansion work; The step of monitoring the water temperature of the cold water tank and sending instructions to adjust the circulation between the cooler and the water tank.

8. A computer storage medium for storing a computing program, characterized in that: When the computer program is read by a computer, the computer executes the method of claim 7.

9. A computer, comprising a processor and a storage medium, characterized in that: When the processor reads the computer program stored in the storage medium, the computer executes the method of claim 7 .

10. A computer program product, being a computer program, characterized in that When the computer program is executed, the method of claim 7 is implemented.

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