Liquid air energy storage, cold and heat recovery, heat storage, cold storage and performance improvement system

Abstract

The invention provides a liquid air energy storage, cold and heat recovery, heat storage, cold storage and performance improvement system, and belongs to the field of liquid air energy storage. The problem that an existing system utilizing the liquid air energy storage technology is low in energy conversion efficiency is solved. The system comprises a liquid air storage device, a heat storage device, a cold energy storage tank set, an energy charging system and an energy discharging system, and the energy charging system comprises a motor, a compressor unit, a heat recovery heat exchanger set, a cold energy supply heat exchanger set and a gas-liquid separation device. The energy release system comprises a liquid air low-temperature pump, a cold energy recovery heat exchanger set, a heat exchanger coupled with an organic Rankine cycle subsystem evaporator, a heat supply heat exchange set, an expansion unit and a generator. The energy charging system can achieve multi-stage compression, heat exchange and cooling, air is liquefied and stored in the liquid air storage device, the energy discharging system can achieve cold energy recovery, liquid air regasification and high-pressure gas heat compensation driving power generation, and the liquid air energy storage system achieves the efficient energy releasing process.

Description

Technical Field

[0001] The present invention belongs to the technical field of liquid air energy storage, and in particular relates to a liquid air energy storage system for heat recovery, heat storage, cold storage and performance improvement. Background Art

[0002] Liquid air energy storage technology is a long-term energy storage technology that uses the phase change process of liquefied air to store energy. The air is cooled to about -196°C through refrigeration technology to turn it into liquid and store it in an insulated tank. When energy needs to be released, the liquid air is vaporized by heating to produce high-pressure gas, which drives the turbine to generate electricity. Liquid air energy storage technology can convert electrical energy into low-temperature latent heat and compressed air for storage, and then convert it back into electrical energy to achieve the time and space transfer of energy. With the increase in the proportion of renewable energy generation such as wind power and solar energy, the volatility and intermittency problems faced by the power system have become increasingly prominent, and the demand for long-term energy storage has increased significantly. Liquid air energy storage technology has the advantage of long-term energy storage, which is suitable for smoothing the fluctuations of renewable energy and enhancing the stability and regulation capacity of the power grid. Existing energy storage technologies, such as lithium batteries and pumped storage, have limited energy density, geographical restrictions or resource supply problems. In contrast, liquid air energy storage technology does not rely on rare metals or specific geographical conditions and has broad deployment potential. The energy storage medium of liquid air energy storage technology is air, which is completely pollution-free. The production process of liquefied air can be combined with industrial waste heat and waste cooling, and has the potential to cooperate with other energy systems, which is in line with the future development trend of low-carbon and environmental protection.

[0003] However, the existing systems using liquid air energy storage technology have low energy conversion efficiency, large energy loss during the energy storage process, and the system cannot be flexibly deployed in energy storage systems of different sizes. In addition, the relevant technical solutions are not yet perfect, which limits large-scale promotion. Summary of the invention

[0004] In view of this, in order to solve the problems that the existing system using liquid air energy storage technology has low energy conversion efficiency, large energy loss in the energy storage process, and the system cannot be flexibly deployed in energy storage systems of different scales, in addition, the current relevant technical solutions are still imperfect, which limits the large-scale promotion. The present invention proposes a liquid air energy storage heat recovery heat storage and cold storage and performance improvement system.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A liquid air energy storage, heat recovery, heat storage, cold storage and performance improvement system, comprising:

[0007] Liquid air storage device, heat storage device and cold energy storage tank group;

[0008] The charging system comprises an electric motor, a compressor unit, a heat recovery heat exchanger unit, a cold energy supply heat exchanger unit and a gas-liquid separation device, wherein the electric motor is connected to the compressor unit, the compressor unit is connected to the heat recovery heat exchanger unit, the heat recovery heat exchanger unit, the cold energy supply heat exchanger unit and the gas-liquid separation device are connected in sequence, the liquid outlet of the gas-liquid separation device is connected to the liquid air storage device, the gas outlet of the gas-liquid separation device is connected to the cold energy supply heat exchanger unit, the cold energy cold storage tank unit is connected to the cold energy supply heat exchanger unit, and the heat recovery heat exchanger unit is connected to the heat storage device;

[0009] The energy release system includes a liquid air cryogenic pump, a cold energy recovery heat exchanger group, a heat exchanger coupled to the evaporator of the organic Rankine cycle subsystem, a heat supply heat exchange group, an expansion unit and a generator. The input end and the output end of the liquid air cryogenic pump are respectively connected to the liquid air storage device and the cold energy recovery heat exchanger group, the high-pressure air inlet and the outlet of the heat exchanger coupled to the evaporator of the organic Rankine cycle subsystem are respectively connected to the cold energy recovery heat exchanger group and the heat supply heat exchanger group, the low-pressure air inlet and the outlet of the heat exchanger coupled to the evaporator of the organic Rankine cycle subsystem are respectively connected to the last-stage expander of the expansion unit and the outside world, the heat storage device can provide heat for the heat exchanger coupled to the evaporator of the organic Rankine cycle subsystem, the heat supply heat exchange group is connected to the expansion unit, the expansion unit is connected to the generator, the heat supply heat exchange group is connected to the heat storage device, and the cold energy recovery heat exchanger group is connected to the cold energy storage tank group. As an optimal solution of the above-mentioned liquid air energy storage, heat recovery, heat storage and performance improvement system, the heat supply heat exchanger group includes a primary heat supply heat exchanger, a secondary heat supply heat exchanger and a tertiary heat supply heat exchanger, the expansion machine group includes a primary expander, a secondary expander and a tertiary expander, and the gas output by the cold energy recovery heat exchanger group passes through the primary heat supply heat exchanger, the primary expansion machine, the secondary heat supply heat exchanger, the secondary expansion machine, the tertiary heat supply heat exchanger and the tertiary expansion machine in sequence.

[0010] As a preferred solution of the above-mentioned liquid air energy storage, heat recovery, heat storage and performance improvement system, the compressor unit includes a first-stage compressor, a second-stage compressor and a third-stage compressor, and the heat recovery heat exchanger group includes a first-stage heat recovery heat exchanger, a second-stage heat recovery heat exchanger and a third-stage heat recovery heat exchanger. The air passes through the first-stage compressor, the first-stage heat recovery heat exchanger, the second-stage compressor, the second-stage heat recovery heat exchanger, the third-stage compressor, the third-stage heat recovery heat exchanger and the cold energy supply heat exchanger group in sequence.

[0011] As a preferred solution of the above-mentioned liquid air energy storage, heat recovery, heat storage, cold storage and performance improvement system, the charging system also includes a connected high-grade external cold energy recovery heat exchanger and an external cold energy supply device, the high-grade external cold energy recovery heat exchanger is arranged between the cold energy supply heat exchanger group and the gas-liquid separation device, and the high-grade external cold energy recovery heat exchanger is also connected to the cold energy storage tank group.

[0012] As a preferred solution of the above-mentioned liquid air energy storage, heat recovery, heat storage, cold storage and performance improvement system, the external cold energy supply device adopts a liquid natural gas supply device or a liquid nitrogen supply device.

[0013] As a preferred solution of the above-mentioned liquid air energy storage, heat recovery, heat storage and performance improvement system, it also includes an organic Rankine cycle subsystem, which includes an evaporator, an expander, a condenser and a compressor. The evaporator, expander, condenser and compressor are connected in sequence, the condenser is connected to the heat exchanger coupled to the evaporator of the organic Rankine cycle subsystem, and the evaporator is connected to the heat storage device.

[0014] As a preferred solution of the above-mentioned liquid air energy storage, heat recovery, heat storage, cold storage and performance improvement system, it also includes an external heat supply device, and the external heat supply device is connected to the heat supply and heat exchange group.

[0015] As a preferred solution of the above-mentioned liquid air energy storage, heat recovery, heat storage, and performance improvement system, the external heat providing device adopts a solar collector or an industrial waste heat recovery device.

[0016] As an optimal solution of the above-mentioned liquid air energy storage, heat recovery, heat storage and performance improvement system, the cold energy storage tank group includes a medium-grade cold energy storage tank and a high-grade cold energy storage tank; the cold energy supply heat exchanger group includes a medium-grade cold energy supply heat exchanger and a high-grade cold energy supply heat exchanger; the cold energy recovery heat exchanger group includes a high-grade cold energy recovery heat exchanger and a medium-grade cold energy recovery heat exchanger, the medium-grade cold energy supply heat exchanger and the medium-grade cold energy recovery heat exchanger are both connected to the medium-grade cold energy storage tank, and the high-grade cold energy supply heat exchanger and the high-grade cold energy recovery heat exchanger are both connected to the high-grade cold energy storage tank.

[0017] As a preferred solution of the above-mentioned liquid air energy storage, heat recovery, heat storage, cold storage and performance improvement system, it also includes a heating device, and the heat storage device is connected to the heating device.

[0018] Compared with the prior art, the liquid air energy storage, heat recovery, heat storage and cold storage and performance improvement system provided by the present invention has the following beneficial effects:

[0019] The present invention provides a liquid air energy storage, heat recovery, heat storage, and performance improvement system, which can realize compression heat recovery, thermal energy storage, high-pressure air reheat expansion, cold storage, and waste heat organic Rankine cycle zero-carbon power generation. The system reasonably sets up an external heat supply device, an external cold supply device, a heat storage device, and a cold energy storage tank group, so as to obtain excess air compression heat, recover heat energy and cold energy without affecting the power generation of the original system, thereby avoiding the waste of high-grade compression heat. At the same time, it can also be integrated with existing new energy systems and liquefied natural gas systems to achieve the purpose of energy saving and carbon reduction, and can be flexibly deployed in energy storage systems of different sizes, especially suitable for large-scale energy storage scenarios. Small modular liquid air energy storage systems can also be further developed, which can be applicable to distributed energy storage needs and have broad commercial and application value.

[0020] The liquid air energy storage heat recovery heat storage and performance improvement system can store both heat and cold energy. It can use the excess heat in the liquid air energy storage system to drive the organic Rankine cycle for zero-carbon power generation, obtain additional power generation, significantly increase the system's power generation, and improve the overall efficiency of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0022] Figure 1 It is a structural schematic diagram of a liquid air energy storage heat recovery heat storage and cold storage and performance improvement system provided by a specific embodiment of the present invention;

[0023] Figure 2 It is a structural schematic diagram of an energy charging system of a liquid air energy storage cold and heat recovery heat storage cold storage and performance improvement system provided by a specific embodiment of the present invention;

[0024] Figure 3 It is a structural schematic diagram of an energy release system of a liquid air energy storage heat recovery heat storage and performance improvement system provided by a specific embodiment of the present invention;

[0025] Figure 4 It is a structural schematic diagram of an organic Rankine cycle subsystem of a liquid air energy storage heat recovery heat storage and performance improvement system provided by a specific embodiment of the present invention;

[0026] Figure 5 It is a structural schematic diagram of an organic Rankine cycle subsystem and an external heat supply device of a liquid air energy storage heat recovery heat storage and performance improvement system provided in a specific embodiment of the present invention;

[0027] Figure 6It is a structural schematic diagram of a liquid air energy storage heat recovery heat storage and performance improvement system provided in a specific embodiment of the present invention, in which an external heat supply device directly supplies heat to an energy release system.

[0028] In the figure:

[0029] 1. Liquid air storage device;

[0030] 2. Heat storage device;

[0031] 31. Medium-grade cold energy storage tank; 32. High-grade cold energy storage tank;

[0032] 4. Electric motor;

[0033] 51. One-stage compressor; 52. Two-stage compressor; 53. Three-stage compressor;

[0034] 61. Primary heat recovery heat exchanger; 62. Secondary heat recovery heat exchanger; 63. Thirdary heat recovery heat exchanger;

[0035] 71. Medium-grade cold energy supply heat exchanger; 72. High-grade cold energy supply heat exchanger;

[0036] 8. High-grade external cold energy recovery heat exchanger;

[0037] 9. Gas-liquid separation device;

[0038] 10. Liquid air cryogenic pump;

[0039] 111. High-grade cold energy recovery heat exchanger; 112. Medium-grade cold energy recovery heat exchanger;

[0040] 12. Heat exchanger coupled to the evaporator of the organic Rankine cycle subsystem;

[0041] 131. First-stage expander; 132. Second-stage expander; 133. Third-stage expander;

[0042] 141. a primary heat supply heat exchanger; 142. a secondary heat supply heat exchanger; 143. a tertiary heat supply heat exchanger;

[0043] 15. Generator;

[0044] 161. Evaporator; 162. Expander; 163. Condenser; 164. Compressor;

[0045] 17. External heat supply device;

[0046] 18. First wage circulation pump;

[0047] 19. Second working medium circulation pump;

[0048] 20. The third working medium circulation pump;

[0049] 21. Fourth working medium circulation pump;

[0050] 22. Throttle valve;

[0051] 23. First switch valve;

[0052] 24. Second switch valve;

[0053] 25. The first four-way valve;

[0054] 26. Second four-way valve;

[0055] 27. First three-way valve;

[0056] 28. Second three-way valve;

[0057] 29. The third three-way valve;

[0058] 30. Fourth three-way valve. DETAILED DESCRIPTION

[0059] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely explain the technical solutions in the embodiments of the present invention. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict, and the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0060] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0061] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0062] In the description of this embodiment, the terms "upper", "lower", "right" and other directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplified operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0063] See also Figure 1-6 Description of this embodiment. The present invention provides a liquid air energy storage, heat recovery, heat storage, and performance improvement system. The liquid air energy storage, heat recovery, heat storage, and performance improvement system comprises a liquid air storage device 1, a heat storage device 2, a cold energy storage tank group, a charging system, and an energy discharging system. The charging system comprises an electric motor 4, a compressor group, a heat recovery heat exchanger group, a cold energy supply heat exchanger group, and a gas-liquid separation device 9. The electric motor 4 is connected to the compressor group, the compressor group is connected to the heat recovery heat exchanger group, the heat recovery heat exchanger group, the cold energy supply heat exchanger group, and the gas-liquid separation device 9 are connected in sequence. The liquid outlet of the gas-liquid separation device 9 is connected to the liquid air storage device 1, the gas outlet of the gas-liquid separation device 9 is connected to the cold energy supply heat exchanger group, the cold energy storage tank group is connected to the cold energy supply heat exchanger group, and the heat recovery heat exchanger group is connected to the heat storage device 2; the energy discharging system comprises a liquid air cryogenic Pump 10, cold energy recovery heat exchanger group, heat exchanger 12 coupled with the evaporator of the organic Rankine cycle subsystem, heat supply heat exchange group, expansion unit and generator 15, the input end and output end of the liquid air cryogenic pump 10 are respectively connected to the liquid air storage device 1 and the cold energy recovery heat exchanger group, the high-pressure air inlet and outlet of the heat exchanger 12 coupled with the evaporator of the organic Rankine cycle subsystem are respectively connected to the cold energy recovery heat exchanger group and the heat supply heat exchanger group, the low-pressure air inlet and outlet of the heat exchanger 12 coupled with the evaporator of the organic Rankine cycle subsystem are respectively connected to the last-stage expander 131 of the expansion unit and the outside world, the heat storage device 2 can provide heat for the heat exchanger 12 coupled with the evaporator of the organic Rankine cycle subsystem, the heat supply heat exchange group is connected to the expansion unit, the expansion unit is connected to the generator 15, the heat supply heat exchange group is connected to the heat storage device 2, and the cold energy recovery heat exchanger group is connected to the cold energy cold storage tank group.

[0064] like Figure 1 and Figure 2As shown, the charging process of the liquid air energy storage heat recovery heat storage and performance improvement system is as follows: first, the ambient air is sucked into the compressor unit and compressed step by step by the compressor unit. During this process, the pressure of the air increases significantly, and each stage of compression also causes the temperature of the air to rise. The high-temperature air after each stage of compression enters the heat recovery heat exchanger group, and the compressed air releases heat to the external circulating heat exchange medium through the heat recovery heat exchanger group. The heat exchange medium takes away the heat and stores it in the heat storage device 2. After the heat exchange of the heat recovery heat exchanger group, the compressed air will be further cooled by the cold energy supply heat exchanger group. The cold energy supply heat exchanger group extracts the cold energy in the cold energy storage tank group and reduces the air temperature to an extremely low value. After cooling, the compressed air gradually reaches the liquefaction temperature (about -196°C). Finally, the low-temperature liquid air and gaseous air are separated by the gas-liquid separation device 9. The liquid air separated by the gas-liquid separation device 9 flows into the liquid air storage device 1 for storage, and the gaseous air separated by the gas-liquid separation device 9 enters the cold energy supply heat exchanger group for recycling gaseous air. The entire charging process liquefies the air through multi-stage compression, heat exchange and cooling and stores it in the liquid air storage device 1.

[0065] Among them, the required pressure is finally reached by compressing in sequence through the compressor group and recovering heat in sequence through the heat recovery heat exchanger group. The heat recovery heat exchanger group recovers heat in order to reduce the temperature of the air and store the heat energy generated by the compression process to increase the heat for the subsequent power generation process and improve the system efficiency.

[0066] like Figure 1 and Figure 3As shown, the energy release process of the liquid air energy storage, heat recovery, heat storage and performance improvement system is as follows: the liquid air stored in the liquid air storage device 1 is extracted through the liquid air cryogenic pump 10, and then first passes through the cold energy recovery heat exchanger group to transfer the cold energy and store it in the cold energy storage tank group, which is used for the high-pressure air reliquefaction process in the subsequent charging process, which helps to improve the overall efficiency of the system. After the cold energy is recovered, the liquid air enters the heat exchanger 12 coupled to the evaporator of the organic Rankine cycle subsystem. The exhaust air recovered from the expansion unit is first used to preheat the high-pressure air. The recovery of exhaust heat helps to improve the overall efficiency of the system. The preliminarily preheated high-pressure air is heated using the waste heat previously stored in the heat storage device 2. As the temperature rises, the liquid air quickly vaporizes and expands into high-pressure gas. The vaporized high-pressure air enters the expansion unit, driving the turbine to rotate, thereby driving the generator 15 to generate electricity. As the air expands in the turbine, the released mechanical energy is converted into electrical energy. After each stage of high-pressure air passes through the turbine, the high-pressure air temperature will drop again, and then the temperature will be raised through each stage of heat supply heat exchanger 141, and the cycle will continue until the air pressure drops to close to the ambient pressure. Finally, the low-pressure air discharged from the last stage of the expansion unit is safely discharged back into the atmosphere after recovering part of the temperature through the heat exchanger 12 coupled to the evaporator of the organic Rankine cycle subsystem. The entire energy release process is driven by cold recovery, regasification of liquid air, and high-pressure gas heat supplement to drive power generation, and the liquid air energy storage system achieves an efficient energy release process.

[0067] It can be understood that the structure of the heat exchanger is the prior art. The two fluids in the heat exchanger in this embodiment are compressed gas and heat exchange fluid for heat recovery and utilization.

[0068] Optionally, during the charging process and the discharging process, the heat exchange fluid for heat recovery and utilization is thermal oil, silicone oil, mineral oil, air, steam, ethylene glycol solution, salt solution or other heat exchange fluids.

[0069] In this embodiment, a throttle valve is provided between the liquid outlet of the gas-liquid separation device 9 and the liquid air storage device 1 .

[0070] Optionally, an air purification device is provided before the compressor unit to remove mechanical impurities, dust and liquid droplets. The ambient air is sucked into the compressor unit after mechanical impurities, dust and liquid droplets are removed by the air purification device.

[0071] In this embodiment, Figure 2As shown, the compressor unit includes a primary compressor 51, a secondary compressor 52 and a tertiary compressor 53, and the heat recovery heat exchanger unit includes a primary heat recovery heat exchanger 61, a secondary heat recovery heat exchanger 62 and a tertiary heat recovery heat exchanger 63. The air passes through the primary compressor 51, the primary heat recovery heat exchanger 61, the secondary compressor 52, the secondary heat recovery heat exchanger 62, the tertiary compressor 53, the tertiary heat recovery heat exchanger 63 and the cold energy supply heat exchanger unit in sequence. The pressure and temperature of the air increase after passing through each compressor 51 of the compressor unit. The high-temperature air after each stage of compression enters the heat recovery heat exchanger unit, and the heat recovery heat exchanger unit transfers the heat of the high-temperature air to the heat exchange medium, and the heat exchange medium takes away the heat and stores it in the heat storage device 2.

[0072] In this embodiment, Figure 3 As shown, the heat supply heat exchange group includes a primary heat supply heat exchanger 141, a secondary heat supply heat exchanger 142 and a tertiary heat supply heat exchanger 143, the expansion unit includes a primary expansion machine 131, a secondary expansion machine 132 and a tertiary expansion machine 133, and the gas output by the cold energy recovery heat exchanger group passes through the primary heat supply heat exchanger 141, the primary expansion machine 131, the secondary heat supply heat exchanger 142, the secondary expansion machine 132, the tertiary heat supply heat exchanger 143 and the tertiary expansion machine 133 in sequence. The gasified high-pressure air enters the expansion unit, and after passing through each stage of the expansion machine 131, the temperature of the high-pressure air will decrease, and then the temperature will be increased through each stage of the heat supply heat exchanger 141, and the cycle will continue until the air pressure drops to close to the ambient pressure.

[0073] Specifically, the cold energy storage tank group includes a medium-grade cold energy storage tank 31 and a high-grade cold energy storage tank 32; the cold energy supply heat exchanger group includes a medium-grade cold energy supply heat exchanger 71 and a high-grade cold energy supply heat exchanger 72; the cold energy recovery heat exchanger group includes a high-grade cold energy recovery heat exchanger 111 and a medium-grade cold energy recovery heat exchanger 112, the medium-grade cold energy supply heat exchanger 71 and the medium-grade cold energy recovery heat exchanger 112 are both connected to the medium-grade cold energy storage tank 31, and the high-grade cold energy supply heat exchanger 72 and the high-grade cold energy recovery heat exchanger 111 are both connected to the high-grade cold energy storage tank 32.

[0074] In other embodiments, the heat recovery heat exchanger group, compressor group, heat supply heat exchanger group, expansion unit, cold energy storage tank group, cold energy supply heat exchanger group and cold energy recovery heat exchanger group are all multi-stage structures, and the number of stages can be designed according to actual operating requirements.

[0075] Optionally, the cold storage material in the medium-grade cold energy cold storage tank 31 is ethylene glycol, propane, methanol, carbon dioxide, ethylene, air, freon or other cold storage liquids, and the medium-grade cold energy cold storage tank 31 can be a single tank design or a multi-tank design. The cold storage material in the high-grade cold energy cold storage tank 32 is liquid nitrogen, methane, liquid air, air or other cold storage liquids, and the high-grade cold energy cold storage tank 32 can be a single tank design or a multi-tank design.

[0076] like Figure 3 As shown, optionally, the liquid air energy storage heat recovery heat storage and performance improvement system also includes an organic Rankine cycle subsystem, the organic Rankine cycle subsystem includes an evaporator 161, an expander 162, a condenser 163 and a compressor 164, the evaporator 161, the expander 162, the condenser 163 and the compressor 164 are connected in sequence, the condenser 163 is connected to the heat exchanger 12 coupled to the evaporator of the organic Rankine cycle subsystem, and the evaporator 161 is connected to the heat storage device 2.

[0077] The liquid air energy storage, heat recovery, heat storage, and performance improvement system can utilize excess heat and cold in the system to drive the organic Rankine cycle for zero-carbon power generation, obtain additional power generation, significantly increase system power generation, and improve the overall efficiency of the system.

[0078] Specifically, the condenser 163 of the organic Rankine cycle subsystem is integrated with the heat exchanger 12 coupled to the evaporator of the organic Rankine cycle subsystem, or connected through a circulating working fluid to serve as a cold source; the evaporator 161 of the organic Rankine cycle subsystem is integrated with the heat storage device 2, or connected through a circulating working fluid to serve as a heat source.

[0079] The heat exchanger 12 coupled to the evaporator of the organic Rankine cycle subsystem is a device that can realize three-channel fluid heat exchange. The first channel is high-pressure air, the high-pressure air inlet is connected to the medium-grade cold energy recovery heat exchanger 112, and the high-pressure air outlet is connected to the heat supply heat exchanger group; the second channel is low-pressure air, the low-pressure air inlet is connected to the three-stage expander 133 of the expansion unit, and the low-pressure air outlet is connected to the outside world, which is used to recover the heat of the low-pressure air, and also use the heat of the recovered air to preheat the high-pressure air of the first channel. The third channel is the heat exchange medium channel of the organic Rankine cycle subsystem, which provides a cold source for the organic Rankine cycle subsystem and can also heat the high-pressure air of the first channel.

[0080] like Figure 1 and Figure 2As shown, optionally, the charging system also includes a high-grade external cold energy recovery heat exchanger 8 and an external cold energy supply device connected, the high-grade external cold energy recovery heat exchanger 8 is arranged between the cold energy supply heat exchanger group and the gas-liquid separation device 9, and the high-grade external cold energy recovery heat exchanger 8 is also connected to the cold energy cold storage tank group. It is used to supplement the cold energy from the outside and recover and store the external cold energy when the cold energy in the compressed air is insufficient. During the charging process, when the cold energy of the liquefied air in the system is insufficient, the external cold energy can provide cold energy to the compressed air through the high-grade external cold energy recovery heat exchanger 8. In the process of recovering and storing the external cold energy, the compressed air is first cooled by the high-grade external cold energy recovery heat exchanger 8, and then the excess cold energy is stored in the cold energy cold storage tank group, and the excess cold energy is stored in the cold energy cold storage tank group for the compressed air to be used again.

[0081] Optionally, the external cold energy supply device adopts a liquefied natural gas supply device or a liquid nitrogen supply device. The high-grade external cold energy of the high-grade external cold energy recovery heat exchanger 8 can be provided by liquefied natural gas, or by liquid nitrogen or other cryogenic devices.

[0082] like Figure 5 and Figure 6 As shown, optionally, the liquid air energy storage heat recovery heat storage and performance improvement system further includes an external heat supply device 17, and the external heat supply device 17 is connected to the heat supply heat exchange group. During the energy release process, the external heat supply device 17 can supply heat to the heat supply heat exchange group. It can be understood that the external heat supply device 17 and the heat supply heat exchange group can be connected through a heat exchange fluid, so that the gas temperature is increased through heat exchange between the heat exchange fluid and the gas.

[0083] Optionally, the external heat providing device 17 adopts a solar collector or an industrial waste heat recovery device.

[0084] Optionally, the liquid air energy storage heat recovery heat storage and performance improvement system also includes a heating device, and the heat storage device 2 is connected to the heating device. The heat storage device 2 can also be combined with the heating device to realize the heat conversion and electrical storage of renewable energy (photovoltaic, wind power, low-cost electricity) to supplement additional heat for the system.

[0085] Optionally, the heat storage device 2 is filled with heat storage materials, which may be the same heat storage materials as the heat exchange fluid, or other modular heat storage materials, such as sensible heat storage materials, phase change heat storage materials, or thermochemical heat storage materials. The heat storage device 2 may be filled with sensible heat storage materials and latent heat storage materials, or may be filled with multiple types of heat storage materials. The heat storage device 2 may be a single-stage heat storage structure or a multi-stage heat storage structure, and the number and volume of the heat storage tanks may be adjusted according to actual operating requirements.

[0086] Optionally, the pipelines and related equipment components of the liquid air energy storage heat recovery heat storage and performance improvement system are insulated to reduce energy loss and ensure safe operation, and all insulation materials are installed with a protective shell.

[0087] Optionally, a first working fluid circulation pump 18 is provided between the heat storage device 2 and the front end of the heat recovery heat exchanger group, a second working fluid circulation pump 19 is provided between the heat storage device 2 and the tail end of the heat supply heat exchange group, a third working fluid circulation pump 20 is provided between the external heat providing device 17 and the tail end of the heat supply heat exchange group, and a fourth working fluid circulation pump is provided between the condenser of the organic Rankine cycle subsystem and the heat exchanger 12 coupled to the evaporator of the organic Rankine cycle subsystem.

[0088] Optionally, the first working fluid circulation pump 18, the second working fluid circulation pump 19, the third working fluid circulation pump 20 and the fourth working fluid circulation pump are controlled by frequency conversion, and the control flow and stroke can be designed according to actual operation requirements.

[0089] The liquid air energy storage heat recovery heat storage and performance improvement system can realize compression heat recovery, thermal energy storage, high-pressure air reheat expansion, cold storage, and waste heat organic Rankine cycle zero-carbon power generation. The system obtains excess air compression heat, recovers heat and cold energy without affecting the power generation of the original system by reasonably setting the external heat supply device 17, the external cold supply device, the heat storage device 2 and the cold energy cold storage tank group, thereby avoiding the waste of high-grade compression heat. At the same time, it can also be integrated with the existing new energy system and liquefied natural gas system to achieve the purpose of energy saving and carbon reduction, and can be flexibly deployed in energy storage systems of different sizes, especially suitable for large-scale energy storage scenarios. Small modular liquid air energy storage systems can also be further developed, which can be applicable to distributed energy storage needs and have broad commercial and application value.

[0090] The liquid air energy storage heat recovery heat storage and performance improvement system can store both heat and cold energy. It can use the excess heat in the liquid air energy storage system to drive the organic Rankine cycle for zero-carbon power generation, obtain additional power generation, significantly increase the system's power generation, and improve the overall efficiency of the system.

[0091] Obviously, the embodiments of the present invention disclosed above are only used to help illustrate the present invention. The embodiments do not describe all the details in detail, nor do they limit the invention to the specific embodiments described. According to the content of this specification, many modifications and changes can be made. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that technicians in the relevant technical field can understand and use the present invention well. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A liquid air energy storage, heat recovery, heat storage, cold storage and performance improvement system, characterized in that: include: A liquid air storage device (1), a heat storage device (2) and a cold energy storage tank group; The charging system comprises an electric motor (4), a compressor group, a heat recovery heat exchanger group, a cold energy supply heat exchanger group and a gas-liquid separation device (9), wherein the electric motor (4) is connected to the compressor group, the compressor group is connected to the heat recovery heat exchanger group, the heat recovery heat exchanger group, the cold energy supply heat exchanger group and the gas-liquid separation device (9) are connected in sequence, the liquid outlet of the gas-liquid separation device (9) is connected to the liquid air storage device (1), the gas outlet of the gas-liquid separation device (9) is connected to the cold energy supply heat exchanger group, the cold energy cold storage tank group is connected to the cold energy supply heat exchanger group, and the heat recovery heat exchanger group is connected to the heat storage device (2); The energy release system comprises a liquid air cryogenic pump (10), a cold energy recovery heat exchanger group, a heat exchanger (12) coupled to an evaporator of an organic Rankine cycle subsystem, a heat supply heat exchange group, an expansion unit and a generator (15), wherein the input end and the output end of the liquid air cryogenic pump (10) are respectively connected to the liquid air storage device (1) and the cold energy recovery heat exchanger group, and the high-pressure air inlet and outlet of the heat exchanger (12) coupled to the evaporator of the organic Rankine cycle subsystem are respectively connected to the cold energy recovery heat exchanger group and the heat supply heat exchanger group. The low-pressure air inlet and outlet of the heat exchanger (12) coupled to the evaporator of the organic Rankine cycle subsystem are respectively connected to the last-stage expander (131) of the expansion unit and the outside world. The heat storage device (2) can supply heat to the heat exchanger (12) coupled to the evaporator of the organic Rankine cycle subsystem. The heat supply heat exchange group is connected to the expansion unit, the expansion unit is connected to the generator (15), the heat supply heat exchange group is connected to the heat storage device (2), and the cold energy recovery heat exchanger group is connected to the cold energy storage tank group.

2. The liquid air energy storage, heat recovery, heat storage, and performance improvement system according to claim 1 is characterized by: The heat supply heat exchange group includes a primary heat supply heat exchanger (141), a secondary heat supply heat exchanger (142) and a tertiary heat supply heat exchanger (143); the expansion machine group includes a primary expansion machine (131), a secondary expansion machine (132) and a tertiary expansion machine (133); the gas output by the cold energy recovery heat exchanger group passes through the primary heat supply heat exchanger (141), the primary expansion machine (131), the secondary heat supply heat exchanger (142), the secondary expansion machine (132), the tertiary heat supply heat exchanger (143) and the tertiary expansion machine (133) in sequence.

3. The liquid air energy storage, heat recovery, heat storage, and performance improvement system according to claim 1 is characterized by: The compressor group includes a primary compressor (51), a secondary compressor (52) and a tertiary compressor (53); the heat recovery heat exchanger group includes a primary heat recovery heat exchanger (61), a secondary heat recovery heat exchanger (62) and a tertiary heat recovery heat exchanger (63); air passes through the primary compressor (51), the primary heat recovery heat exchanger (61), the secondary compressor (52), the secondary heat recovery heat exchanger (62), the tertiary compressor (53), the tertiary heat recovery heat exchanger (63) and the cold energy supply heat exchanger group in sequence.

4. The liquid air energy storage, heat recovery, heat storage, and performance improvement system according to claim 1 is characterized by: The charging system also includes a high-quality external cold energy recovery heat exchanger (8) and an external cold energy supply device connected thereto. The high-quality external cold energy recovery heat exchanger (8) is arranged between the cold energy supply heat exchanger group and the gas-liquid separation device (9). The high-quality external cold energy recovery heat exchanger (8) is also connected to the cold energy storage tank group.

5. The liquid air energy storage, heat recovery, heat storage, and performance improvement system according to claim 4 is characterized by: The external cold energy supply device adopts a liquid natural gas supply device or a liquid nitrogen supply device.

6. The liquid air energy storage, heat recovery, heat storage, and performance improvement system according to claim 1 is characterized by: The invention also includes an organic Rankine cycle subsystem, wherein the organic Rankine cycle subsystem includes an evaporator (161), an expander (162), a condenser (163) and a compressor (164), wherein the evaporator (161), the expander (162), the condenser (163) and the compressor (164) are connected in sequence, wherein the condenser (163) is connected to a heat exchanger (12) coupled to the evaporator of the organic Rankine cycle subsystem, and the evaporator (161) is connected to the heat storage device (2).

7. The liquid air energy storage, heat recovery, heat storage, and performance improvement system according to claim 1 is characterized by: It also includes an external heat supply device (17), and the external heat supply device (17) is connected to the heat supply and heat exchange group.

8. The liquid air energy storage, heat recovery, heat storage, and performance improvement system according to claim 7 is characterized by: The external heat supply device (17) adopts a solar collector or an industrial waste heat recovery device.

9. The liquid air energy storage, heat recovery, heat storage, and performance improvement system according to claim 1 is characterized by: The cold energy storage tank group comprises a medium-grade cold energy storage tank (31) and a high-grade cold energy storage tank (32); the cold energy supply heat exchanger group comprises a medium-grade cold energy supply heat exchanger (71) and a high-grade cold energy supply heat exchanger (72); the cold energy recovery heat exchanger group comprises a high-grade cold energy recovery heat exchanger (111) and a medium-grade cold energy recovery heat exchanger (112); the medium-grade cold energy supply heat exchanger (71) and the medium-grade cold energy recovery heat exchanger (112) are both connected to the medium-grade cold energy storage tank (31), and the high-grade cold energy supply heat exchanger (72) and the high-grade cold energy recovery heat exchanger (111) are both connected to the high-grade cold energy storage tank (32).

10. The liquid air energy storage, heat recovery, heat storage, and performance improvement system according to claim 1 is characterized by: It also comprises a heating device, and the heat storage device (2) is connected to the heating device.

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