Liquid air energy storage subsystem and coupling system

Abstract

The present application relates to the technical fields of liquid air energy storage, and discloses a liquid air energy storage subsystem and a coupling system. The liquid air energy storage subsystem comprises a heat storage unit and a cold storage unit; the heat storage unit and the cold storage unit are both buried underground; the cold storage unit is in gas communication with the heat storage unit. In the energy storage stage, the heat storage unit is used for storing compression heat, and the cold storage unit is used for pre-cooling the compressed air discharged from the heat storage unit to liquefy the compressed air. In the energy releasing stage, the cold storage unit is used for rewarming the liquid air, and the heat storage unit is used for reheating the air discharged from the cold storage unit to gasify the liquid air. By burying the heat storage unit and the cold storage unit underground, not only the land occupation area is effectively reduced, but also the construction cost of the high-pressure heat and cold storage is greatly reduced compared with the ground high-pressure heat and cold storage, and the safety hazards caused by the ground high-pressure equipment are avoided, thus solving the problems of the current liquid air energy storage technology, i.e., the safety hazards of the heat and cold storage units and the large land occupation area.

Description

Technical Field

[0001] This invention relates to the field of liquid air energy storage technology, and in particular to a liquid air energy storage subsystem and its coupling system. Background Technology

[0002] Liquid air energy storage technology boasts advantages such as cleanliness, low carbon footprint, safety, long lifespan, and the ability to provide rotational inertia support, making it one of the most competitive long-term energy storage technologies capable of coupling with new energy power generation and supporting new power systems. In the energy storage phase, air is compressed, purified, and cooled before entering the cold storage unit. The resulting liquid air, after cooling and liquefaction, is stored in a liquid air tank, while the heat of compression is stored in the heat storage unit. In the energy release phase, the liquid air first passes through the cold storage unit, where it is vaporized and reheated, and the cold energy is recovered. The reheated air then enters the heat storage unit, where it is heated by the recovered heat of compression. The heated air then enters the expander unit to drive a generator to produce electricity. In this technology, the cold and heat storage units are crucial for ensuring the efficiency of the liquid air energy storage subsystem.

[0003] In current liquid air energy storage technologies, the heat storage unit typically uses heat transfer oil or molten salt as the heat storage medium, posing risks of leakage and safety hazards. The cold storage unit is mainly divided into liquid-phase cold storage and solid-phase cold storage technologies. Solid-phase cold storage technology uses rocks, gravel, and glass spheres as the cold storage medium, which is safer than liquid-phase cold storage technologies using flammable and explosive media such as methanol and propane, and is one of the important directions for the large-scale development of future liquid air energy storage technologies. However, because traditional atmospheric pressure solid-phase cold storage systems generate a thermocline during the energy storage and release interval, reducing system efficiency, liquid air energy storage technologies based on traditional solid-phase cold storage methods cannot yet be commercially applied on a large scale.

[0004] In recent years, to address the low efficiency of liquid air energy storage subsystems based on traditional solid-phase cold storage technology, researchers have proposed technologies including fluidized solid-phase cold storage, liquid air energy storage using combined solid-phase cold accumulators, and high-pressure solid-phase cold storage. Among these, fluidized solid-phase cold storage suffers from problems such as fluidization abrasion of the solid-phase cold storage medium and difficulty in automatic transport and control, severely restricting its large-scale application. Liquid air energy storage using combined solid-phase cold accumulators requires a large footprint. Using high-pressure solid-phase cold accumulators to mitigate the effects of the thermocline introduces safety hazards, diminishing the significant safety advantage of solid-phase cold storage compared to liquid-phase cold storage. Therefore, current liquid air energy storage technologies suffer from safety hazards in thermal and thermal storage units and require a large footprint. Summary of the Invention

[0005] This invention provides a liquid air energy storage subsystem and coupling system to solve the safety hazards of heat and cold storage units in existing liquid air energy storage technologies and the problem of large footprint of combined solid-phase heat and cold storage devices.

[0006] This invention provides a liquid air energy storage subsystem, comprising:

[0007] The heat storage unit is buried underground;

[0008] The cold storage unit is buried underground; the cold storage unit is connected to the heat storage unit via gas passages.

[0009] During the energy storage phase, the heat storage unit is used to store the heat of compression, and the cold storage unit is used to pre-cool the compressed air discharged from the heat storage unit so as to liquefy the compressed air.

[0010] During the energy release phase, the cold storage unit is used to reheat the liquid air, and the heat storage unit is used to reheat the air discharged from the cold storage unit to vaporize the liquid air.

[0011] According to the liquid air energy storage subsystem provided by the present invention, the heat storage unit has a heat storage cavity filled with a solid phase heat storage medium; the cold storage unit has a cold storage cavity filled with a solid phase cold storage medium; and the heat storage cavity and the cold storage cavity are connected by a gas path.

[0012] According to the liquid air energy storage subsystem provided by the present invention, the heat storage chamber includes

[0013] The first straight segment, the first end of the first straight segment is connected to the air circuit of the air compressor unit;

[0014] The second straight segment is disposed on one side of the first straight segment, and the first end of the second straight segment is connected to the gas passage of the cold storage chamber;

[0015] The arc segment has two ends that are respectively connected to the second end of the first straight segment and the second end of the second straight segment via air passages.

[0016] According to the liquid air energy storage subsystem provided by the present invention, the heat storage unit includes:

[0017] Inner shell, the inner shell having the heat storage cavity;

[0018] An outer shell is formed on the outside of the inner shell and forms a filling gap between them; the filling gap is used to accommodate a heat-insulating / cold-insulating medium.

[0019] According to the liquid air energy storage subsystem provided by the present invention, the outer shell has a recessed portion located between the first straight segment and the second straight segment.

[0020] According to the liquid air energy storage subsystem provided by the present invention, the operating temperature of the heat storage unit is -196℃ to 20℃ and the operating pressure is 1.5MPa to 10MPa; the operating temperature of the cold storage unit is 20℃ to 400℃ and the operating pressure is 1.5MPa to 15MPa.

[0021] The liquid air energy storage subsystem provided by the present invention further includes:

[0022] A gas reversal assembly, wherein the inlet end of the gas reversal assembly is used to connect with the outlet gas path of the liquid air storage tank, and the outlet end of the gas reversal assembly is used to connect with the inlet gas path of the air compressor unit.

[0023] According to the liquid air energy storage subsystem provided by the present invention, the gas reflux assembly includes:

[0024] A gas reflux pipe, wherein the inlet end of the gas reflux pipe is used to connect with the gas outlet of the liquid air storage tank;

[0025] A coil is installed inside the cold storage chamber; the air inlet of the coil is connected to the air outlet of the gas reflux pipe.

[0026] A return pipe, wherein the air inlet end of the return pipe is connected to the air outlet end of the coil, and the air outlet end of the return pipe is used to connect to the air inlet end of the air compressor unit.

[0027] The fifth valve body is located in the return pipe.

[0028] The liquid air energy storage subsystem provided by the present invention further includes:

[0029] A pressure-reducing component, wherein the liquid inlet of the pressure-reducing component is connected to the liquid outlet of the cold storage unit;

[0030] A liquid air storage tank, connected to the outlet of the pressure-reducing component, is used to store atmospheric pressure liquid air.

[0031] A second aspect of the present invention provides a liquid air energy storage coupling system, comprising:

[0032] The liquid air energy storage subsystem described in any of the above claims further includes a turbine unit, wherein the air outlet of the heat storage unit is connected to the air inlet of the turbine unit for supplying high-temperature air to the turbine unit, the high-temperature air entering the turbine unit drives the generator to generate electricity and cool down, and the air outlet of the turbine unit is used to discharge the cooled air.

[0033] A biomass gasification subsystem, comprising a biomass gasifier; the gasifying agent inlet of the biomass gasifier is connected to the air outlet of the turbine unit.

[0034] The liquid air energy storage subsystem provided by this invention, by burying the heat storage unit and the cold storage unit underground, not only effectively reduces the land area occupied, but also significantly reduces the construction cost compared to above-ground high-pressure heat and cold storage, and avoids the safety hazards caused by above-ground high-pressure equipment, thus improving the safety of the system. It solves the problems of safety hazards and large land area occupied by the heat and cold storage units in the current liquid air energy storage technology.

[0035] The liquid air energy storage coupling system of the present invention includes the above-mentioned liquid air energy storage subsystem, and therefore has at least the above-mentioned advantages. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0037] Figure 1 This is one of the structural schematic diagrams of a liquid air energy storage coupling system provided by the present invention.

[0038] Figure 2 This is the second schematic diagram of a liquid air energy storage coupling system provided by the present invention.

[0039] Figure 3 This is a schematic diagram of the liquid air energy storage subsystem provided by the present invention.

[0040] Figure 4 This is one of the structural schematic diagrams of the heat storage unit of the liquid air energy storage subsystem provided by the present invention.

[0041] Figure 5 yes Figure 4 A schematic diagram of the cross-sectional structure of the heat storage unit from a top-down perspective.

[0042] Figure 6 yes Figure 4 A schematic diagram of the cross-sectional structure of the heat storage unit under the main view.

[0043] Figure 7 This is the second schematic diagram of the heat storage unit of the liquid air energy storage subsystem provided by the present invention.

[0044] Figure 8 yes Figure 7A schematic diagram of the cross-sectional structure of the heat storage unit from a top-down perspective.

[0045] Figure 9 yes Figure 7 A schematic diagram of the cross-sectional structure of the heat storage unit under the main view.

[0046] Figure label:

[0047] 100. Heat storage unit; 110. Heat storage chamber; 120. Inner shell; 130. Outer shell; 140. Filling gap; 111. First straight segment; 112. Second straight segment; 113. Arc segment; 131. Recess;

[0048] 200. Cold storage unit;

[0049] 310. Gas reflux pipe; 320. Coil; 330. Return pipe; 340. Fifth valve body;

[0050] 400. Pressure reducing assembly; 410. Liquid expander; 420. Throttling valve;

[0051] 500. Liquid air storage tank;

[0052] 600. Energy release assembly; 610. Cryogenic pump; 620. Energy release gas pipeline; 630. Turbine unit; 640. Sixth valve body;

[0053] 700, Energy storage component; 710, Air compressor unit; 720, First air supply pipe; 730, First valve body;

[0054] 810. Second gas supply pipe; 820. Third valve body;

[0055] 910. Second valve body; 920. Fourth valve body;

[0056] 50. Biomass gasification furnace;

[0057] 60. Syngas storage tank;

[0058] 70. Raw material supply components; 71. Biomass storage bins; 72. Cutting and shaping machine; 73. Hoppers; 74. Belt conveyors; 75. Crusher bins; 76. Locking hoppers;

[0059] 80. Syngas purification unit; 81. Cyclone separator; 82. Tar reformer;

[0060] 1. First intake pipe; 2. Second intake pipe; 3. Third intake pipe; 4. First switching valve; 5. Second switching valve; 6. Third switching valve; 7. Electronic system; 8. Chemical substance production subsystem;

[0061] 90. Heat storage component; 91. Heat accumulator; 92. Blower. Detailed Implementation

[0062] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0063] In the description of the embodiments of this invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the embodiments of this invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0064] In the description of this invention patent, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this invention patent based on the specific circumstances.

[0065] In the embodiments of this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0066] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0067] The following is combined Figures 3 to 9 The liquid air energy storage subsystem of the present invention will be described in detail.

[0068] like Figure 3 As shown, a specific embodiment of the present invention provides a liquid air energy storage subsystem. This liquid air energy storage subsystem includes a heat storage unit 100 and a cold storage unit 200; both the heat storage unit 100 and the cold storage unit 200 are buried underground; the cold storage unit 200 is connected to the heat storage unit 100 via a gas path. During the energy storage phase, the heat storage unit 100 stores the heat of compression, and the cold storage unit 200 pre-cools the compressed air discharged from the heat storage unit 100 to liquefy the compressed air. During the energy release phase, the cold storage unit 200 reheats the liquid air, and the heat storage unit 100 reheats the air discharged from the cold storage unit 200 to vaporize the liquid air. Specifically, during the energy storage phase, high-temperature, high-pressure compressed air enters the heat storage unit 100, storing the heat of compression in the heat storage unit 100. The cooled high-pressure air then enters the cold storage unit 200, where it is further cooled and liquefied to obtain high-pressure liquid air. During the heat release stage, atmospheric pressure liquid air enters the cold storage unit 200 for vaporization and rewarming. The rewarmed air then enters the heat storage unit 100 for further heating and vaporization. Finally, the heated air is used for power generation.

[0069] In this embodiment, by burying the heat storage unit 100 and the cold storage unit 200 underground, not only is the land area effectively reduced, but the construction cost is also significantly lowered compared to above-ground high-pressure heat and cold storage. Furthermore, the safety hazards caused by above-ground high-pressure equipment are avoided, the safety of the system is improved, and the problems of the current liquid air energy storage technology, such as the safety hazards in the heat and cold storage unit 200 and the large land area required, are solved.

[0070] Furthermore, the second end of the heat storage unit 100 is connected to the first end of the cold storage unit 200 via a second gas supply pipe 810. A third valve body 820 is provided on the second gas supply pipe 810, which is used to control the opening and closing of the gas passage of the second gas supply pipe 810. During the energy storage and release interval, the third valve body 820 is closed.

[0071] It should be noted that the number of heat storage units 100 and cold storage units 200 is not limited in the specific embodiments of the present invention. When the liquid air energy storage subsystem includes multiple heat storage units 100, the multiple heat storage units 100 can be connected in parallel or in series. When the liquid air energy storage subsystem includes multiple cold storage units 200, the multiple cold storage units 200 can be connected in parallel or in series.

[0072] Taking multiple heat storage units 100 connected in parallel as an example, the first end of each heat storage unit 100 is connected to the air outlet of the air compressor unit 710, and the second end of each heat storage unit 100 is connected to the air inlet of the second air supply pipe 810. The air outlet of the second air supply pipe 810 is connected to the first end of the air passage of the cold storage unit 200. At this time, the high-temperature and high-pressure air discharged from the air compressor unit 710 can simultaneously enter the multiple heat storage units 100, and then simultaneously exit from the multiple heat storage units 100, entering the cold storage unit 200 through the second air supply pipe 810.

[0073] Taking multiple heat storage units 100 connected in series as an example, the first and last air passages of the multiple heat storage units 100 are connected sequentially. The first end of the first heat storage unit 100 is connected to the air outlet of the air compressor unit 710, and the second end of the last heat storage unit 100 is connected to the first end of the cold storage unit 200 through the second air supply pipe 810. At this time, the high-temperature and high-pressure air discharged from the air compressor unit 710 passes through the multiple heat storage units 100 sequentially and then enters the cold storage unit 200.

[0074] It is understandable that heat storage can be achieved by connecting one or more heat storage units 100 in series or in parallel, depending on actual needs. Similarly, cold storage can be achieved by connecting one or more cold storage units 200 in series or in parallel, depending on actual needs.

[0075] It should be noted that "multiple" means at least two.

[0076] Furthermore, the heat storage unit 100 has a heat storage chamber 110 filled with a solid-phase heat storage medium; the cold storage unit 200 has a cold storage chamber filled with a solid-phase cold storage medium; the heat storage chamber 110 and the cold storage chamber are connected by a gas path. Specifically, in the energy storage stage, high-temperature and high-pressure compressed air enters the heat storage chamber 110, storing the heat of compression in the solid-phase heat storage medium. The cooled high-pressure air enters the cold storage chamber, where it is further cooled and liquefied by the solid-phase cold storage medium to obtain high-pressure liquid air. In the heat release stage, atmospheric-pressure liquid air enters the cold storage chamber, where the solid-phase cold storage medium vaporizes and reheats the atmospheric-pressure liquid air. The reheated air then enters the heat storage chamber 110, where the solid-phase heat storage medium further heats and vaporizes the reheated air. Finally, the heated air is used for power generation.

[0077] In this embodiment, heat storage and cold storage are achieved through direct heat exchange between air and the heat storage and cold storage medium. Compared to indirect heat exchange using circulating air, the system is more efficient. Compared to indirect heat exchange using chemical media such as heat transfer oil, methanol, and propane, the system does not use flammable and explosive chemicals, making it more environmentally friendly and safer.

[0078] For example, solid-phase heat storage media include solid-phase heat storage materials that are resistant to high temperature and high pressure, such as concrete, rock, or gravel.

[0079] For example, solid-phase heat storage media include high-temperature and low-pressure resistant solid-phase cold storage materials such as rock, glass spheres, concrete, gravel, steel, or magnetite.

[0080] Furthermore, the liquid air energy storage subsystem also includes an insulation layer; the insulation layer is wrapped around the outside of the heat storage unit 100 and / or the cold storage unit 200. By providing an insulation layer on the outside of the heat storage unit 100 and / or the cold storage unit 200, the heat storage and cold storage effects can be further improved.

[0081] Specifically, the heat storage unit 100 is wrapped with insulation materials suitable for underground burial, such as heat insulation cotton, thermal insulation cotton, aluminum silicate cotton, rock wool, asbestos or glass wool, to improve the heat storage effect.

[0082] Specifically, the outside of the cold storage unit 200 is wrapped with deep-cooling insulation materials suitable for underground burial, such as diene deep-cooling insulation cotton, to improve the cold storage effect.

[0083] In other words, the insulation layer includes thermal insulation cotton, insulating cotton, aluminum silicate cotton, rock wool, asbestos, or glass wool. The insulation layer may also include diene cryogenic insulation cotton.

[0084] Specifically, the heat storage unit 100 and the cold storage unit 200 are made of stainless steel, and the outer walls of both units are provided with anti-corrosion layers. These anti-corrosion layers protect the equipment from corrosion and ensure its service life.

[0085] For example, the anti-corrosion layer includes polyethylene anti-corrosion tape and / or an epoxy resin coating. In other words, the outer wall of the heat storage unit 100 is protected against corrosion by means of applying polyethylene anti-corrosion tape or spraying an epoxy resin coating, thus ensuring the equipment's lifespan. The outer wall of the cold storage unit 200 is also protected against corrosion by means of applying polyethylene anti-corrosion tape or spraying an epoxy resin coating, thus ensuring the equipment's lifespan.

[0086] Furthermore, the operating temperature of the heat storage unit 100 is -196℃ to 20℃, and the operating pressure is 1.5MPa to 10MPa; the operating temperature of the cold storage unit 200 is 20℃ to 400℃, and the operating pressure is 1.5MPa to 15MPa.

[0087] In this embodiment, by limiting the operating temperature and operating pressure of the heat storage unit 100 and the cold storage unit 200, the heat storage unit 100 and the cold storage unit 200 are operated in a high-pressure environment. Combined with solid-phase heat storage medium and solid-phase cold storage medium, high-pressure solid-phase heat storage and cold storage are achieved. Compared with atmospheric pressure solid-phase heat storage and cold storage and low-pressure solid-phase heat storage and cold storage, this helps to weaken the influence of the thermocline and improve the system's electro-electric conversion efficiency.

[0088] like Figure 3 As shown, in some embodiments, the liquid air energy storage subsystem includes an energy storage component 700; the energy storage component 700 includes an air compressor unit 710, a first air supply pipe 720, and a first valve body 730; the outlet of the air compressor unit 710 is connected to the first end air passage of the heat storage unit 100 through the first air supply pipe 720; the first valve body 730 is disposed on the first air supply pipe 720 and is used to control the opening and closing of the air passage of the first air supply pipe 720. During the energy storage stage, off-peak electricity such as wind power and photovoltaic power is used as electrical energy to power the air compressor unit 710, and the purified air is compressed to a high temperature and high pressure state by the air compressor unit 710. The compressed high temperature compressed air enters the heat storage chamber 110 of the heat storage unit 100 through the first air supply pipe 720, and directly exchanges heat with the solid phase heat storage medium in the heat storage chamber 110, storing the heat of compression in the solid phase heat storage medium.

[0089] In some embodiments, the liquid air energy storage system further includes a pressure-reducing component 400 and a liquid air storage tank 500. The inlet of the pressure-reducing component 400 is connected to the outlet of the cold storage unit 200. The liquid air storage tank 500 is connected to the outlet of the pressure-reducing component 400 and is used to store atmospheric pressure liquid air. Specifically, during the energy storage stage, the air compressor unit 710 is used to compress ambient temperature and pressure air into high temperature and high pressure air. The high temperature and high pressure air enters the heat storage chamber 110 of the heat storage unit 100 through the first air supply pipe 720 and directly exchanges heat with the solid phase heat storage medium. The heat of compression is stored in the solid phase heat storage medium. The cooled high pressure air enters the cold storage chamber of the cold storage unit 200 and is further cooled and liquefied by the solid phase cold storage medium to obtain high pressure liquid air. The high temperature liquid air enters the pressure-reducing component 400, is depressurized by the pressure-reducing component 400, and is stored in the liquid air storage tank 500. During the energy release phase, the atmospheric pressure liquid air stored in the liquid air storage tank 500 enters the cold storage chamber of the cold storage unit 200 and is directly vaporized and reheated by the solid phase cold storage medium. The reheated air then enters the heat storage chamber 110 of the heat storage unit 100 and is further heated and vaporized by the solid phase heat storage medium. Finally, the heated air is used for power generation.

[0090] In this embodiment, by setting the pressure reduction component 400, the pressure of high-pressure liquid air can be reduced, and the normal-pressure liquid air can be stored in the liquid air storage tank 500, thereby reducing the investment cost of the liquid air storage tank 500 and improving storage safety.

[0091] Furthermore, the pressure-reducing assembly 400 includes a liquid expander 410 and a throttle valve 420. The inlet of the liquid expander 410 is connected to the outlet of the cold storage unit 200; the outlet of the liquid expander 410 is connected to the inlet of the throttle valve 420, and the outlet of the throttle valve 420 is connected to the liquid air storage tank 500. By setting up the liquid expander 410 and the throttle valve 420, the pressure of the high-pressure liquid air is reduced, so that the liquid air is stored in the liquid air storage tank 500 at atmospheric pressure.

[0092] Furthermore, a fourth valve body 920 is provided between the liquid inlet of the liquid expander 410 and the liquid outlet of the cold storage unit 200. The fourth valve body 920 is used to control the opening and closing of the liquid outlet of the cold storage unit 200. During the energy storage and release interval, the fourth valve body 920 is closed.

[0093] Furthermore, a second valve body 910 is provided between the first end of the heat storage unit 100 and the air outlet end of the first valve body 730. The second valve body 910 is used to control the opening and closing of the first end of the heat storage unit 100. During the energy storage and release interval, the second valve body 910 is closed.

[0094] like Figure 3As shown, in some embodiments, the liquid-phase air energy storage system further includes a gas recirculation component; the inlet of the gas recirculation component is connected to the outlet of the liquid air storage tank 500, and the outlet of the gas recirculation component is connected to the inlet of the air compressor unit 710. By setting the gas recirculation component, the air that has not been liquefied in the liquid air storage tank 500 can be returned to the air compressor unit 710 for recompression and liquefaction, avoiding heat waste and improving system efficiency.

[0095] Furthermore, the gas reflux assembly includes a gas reflux pipe 310, a coil 320, a return pipe 330, and a fifth valve body 340. The inlet end of the gas reflux pipe 310 is connected to the outlet gas path of the liquid air storage tank 500. The coil 320 is disposed within the cold storage chamber; the inlet end of the coil 320 is connected to the outlet gas path of the gas reflux pipe 310. The inlet end of the return pipe 330 is connected to the outlet gas path of the coil 320, and the outlet end of the return pipe 330 is connected to the inlet gas path of the air compressor unit 710. The fifth valve body 340 is disposed within the return pipe 330. Specifically, when the fifth valve 340 is opened, the reflux air in the liquid air storage tank 500 enters the coil 320 in the cold storage chamber through the gas reflux pipe 310. The cold energy of the reflux air is recovered through the solid phase cold storage medium. The reflux air after recovering the cold energy re-enters the air compressor unit 710, avoiding heat waste and improving system efficiency.

[0096] like Figure 3 As shown, in some embodiments, the liquid air energy storage subsystem further includes an energy release component 600; the energy release component 600 includes a cryogenic pump 610, an energy release gas delivery pipe 620, and a sixth valve body 640; the inlet of the cryogenic pump 610 is connected to the outlet of the liquid air storage tank 500, and the outlet of the cryogenic pump 610 is connected to the cold storage unit 200; the inlet of the energy release gas delivery pipe 620 is connected to the gas path of the heat storage unit 100. The sixth valve body 640 is disposed on the energy release gas delivery pipe 620. During the energy release phase, the sixth valve 640 opens, and the cryogenic pump 610 draws atmospheric pressure liquid air from the liquid air storage tank 500 to the cold storage chamber of the cold storage unit 200. The solid-phase cold storage medium directly reheats and vaporizes the atmospheric pressure liquid air. The reheated air enters the heat storage chamber 110 of the heat storage unit 100, where the solid-phase heat storage medium directly heats the air, causing the liquid air to vaporize. The gaseous air is discharged through the energy release pipe 620 and can be used for power generation.

[0097] Furthermore, the energy release component 600 also includes a turbine unit 630; the outlet end of the energy release gas pipe 620 is connected to the turbine unit 630, and the heated gaseous air enters the turbine unit 630 to drive the generator to generate electricity.

[0098] like Figures 4 to 9As shown, in some embodiments, the heat storage chamber 110 includes a first straight segment 111, a second straight segment 112, and an arc segment 113; the first end of the first straight segment 111 is connected to the air passage of the air compressor unit 710. The second straight segment 112 is disposed on one side of the first straight segment 111, and the first end of the second straight segment 112 is connected to the air passage of the cold storage chamber. The two ends of the arc segment 113 are respectively connected to the air passages of the second ends of the first straight segment 111 and the second straight segment 112. This design can form a heat storage chamber 110 with a U-shaped structure. The U-shaped structure can better adapt to uneven settlement of the strata and soil compression, reduce the risk of pipeline damage, and thus improve the reliability and safety of the system; the "U"-shaped structure can ensure the uniformity of airflow and stable gas-solid heat transfer, which is more in line with the law of heat conduction and can improve the heat exchange efficiency of the system.

[0099] Specifically, the inner wall of the heat storage chamber 110 needs to withstand high pressure; therefore, the first straight segment 111 and the second straight segment 112 are cylindrical, and the arc segment 113 transitions smoothly with both the first straight segment 111 and the second straight segment 112. In other words, the cross-sections of the first straight segment 111 and the second straight segment 112 of the heat storage chamber 110 in the horizontal plane are circular; the overall cross-section of the heat storage chamber 110 in the vertical direction is U-shaped.

[0100] Furthermore, the cold storage chamber and the heat storage chamber 110 have the same shape.

[0101] In some embodiments, the heat storage unit 100 includes an inner shell 120 and an outer shell 130. The inner shell 120 has a heat storage cavity 110. The outer shell 130 is formed on the outside of the inner shell 120, and a filling gap 140 is formed between the inner shell 120 and the outer shell 130; the filling gap 140 is used to accommodate a heat insulation / cold insulation medium. By providing the outer shell 130 on the outside of the inner shell 120, and forming a filling gap 140 between the inner shell 120 and the outer shell 130, the heat storage effect of the heat storage unit 100 can be improved.

[0102] Furthermore, the structure of the cold storage unit 200 can be the same as that of the heat storage unit 100, and will not be described in detail here. In other words, the cold storage chamber of the cold storage unit 200 has a U-shaped structure, and there is also a filling gap 140 between the outer shell 130 and the inner shell 120 of the cold storage unit 200.

[0103] For example, the thermal insulation / cold insulation medium includes both thermal insulation and cold insulation media; the thermal insulation medium is used to fill the filling gap 140 of the heat storage unit 100; the cold insulation medium is used to fill the filling gap 140 of the cold storage unit 200. The thermal insulation medium includes foamed cement, expanded perlite, foamed glass, vitrified microspheres, foamed ceramics, ceramic fibers, or aerogel perlite. In other words, the filling gap 140 of the heat storage unit 100 can be filled with foamed cement, expanded perlite, foamed glass, vitrified microspheres, foamed ceramics, ceramic fibers, or aerogel perlite. The cold insulation medium includes rigid polyurethane foam or cryogenic rubber and plastic materials. In other words, the filling gap 140 of the cold storage unit 200 is filled with rigid polyurethane foam or cryogenic rubber and plastic materials, etc., as a cold insulation medium.

[0104] Furthermore, the outer casing 130 has a recess 131 located between the first straight segment 111 and the second straight segment 112. In other words, the heat storage unit 100 has a U-shaped cross-section in the vertical direction. The U-shaped heat storage unit 100 can better adapt to uneven settlement of the strata and soil compression, reducing the risk of pipeline damage, thereby improving the reliability and safety of the system; the U-shaped structure can ensure the uniformity of airflow and stable gas-solid heat transfer, which is more in line with the laws of heat conduction and can improve the heat exchange efficiency of the system.

[0105] For example, the outer surface of the housing 130 can be designed as follows, depending on actual needs. Figure 2 The circle shown can also be designed as follows: Figure 5 The square shown.

[0106] Specifically, both the outer shell 130 and the inner shell 120 are made of stainless steel. The outer surface of the outer shell 130 is protected against corrosion by means of attaching polyethylene anti-corrosion tape and spraying epoxy resin coating, thus ensuring the service life of the equipment.

[0107] The following is based on Figure 3 Taking the liquid air energy storage subsystem shown as an example, its working process will be explained in detail:

[0108] During the energy storage phase, the first valve body 730, the second valve body 910, the third valve body 820, the fourth valve body 920, the fifth valve body 340, and the throttle valve 420 are opened. Using off-peak electricity from wind power, photovoltaic power, etc., as the power input, the purified air is compressed to a high temperature and high pressure state by the air compressor unit 710. The compressed high-temperature air then enters the underground heat storage unit 100, where the heat of compression is stored in the solid-phase heat storage medium in the heat storage chamber 110. The cooled compressed air then enters the underground cold storage unit. The heat storage chamber 110 of 200 is further cooled and liquefied to obtain high-pressure liquid air. After the high-pressure liquid air is reduced to the local atmospheric pressure by the liquid expander 410 and the throttle valve 420, it is stored in the liquid air storage tank 500. The reflux air in the liquid air storage tank 500 enters the cold storage chamber of the cold storage unit 200 through the gas reflux pipe 310. The cold energy of the low-temperature air is recovered through the coil 320 in the cold storage chamber. The air after recovering the cold energy enters the air compressor unit 710 again through the return pipe 330.

[0109] During the energy release phase, the first valve body 730 is closed, and the second valve body 910, the third valve body 820, the fourth valve body 920, and the sixth valve body 640 are opened. The atmospheric pressure liquid air in the liquid air storage tank 500 is drawn to the cold storage chamber of the cold storage unit 200 by the cryogenic pump 610. The liquid air is vaporized and reheated by the solid phase cold storage medium. The reheated air enters the heat storage chamber 110 of the heat storage unit 100 through the second gas transmission pipe 810, and is further heated by the solid phase heat storage medium. The heated air enters the turbine unit 630 through the energy release gas transmission pipe 620 to drive the generator to generate electricity.

[0110] During the intermittent storage and release phase, the second valve body 910, the third valve body 820 and the fourth valve body 920 are all in the closed state to maintain a constant pressure in the heat storage unit 100 and the cold storage unit 200.

[0111] Additionally, it should be noted that when the liquid air energy storage subsystem of this embodiment is operated for the first time, liquid nitrogen is required to pre-cool the cold storage unit 200.

[0112] In summary, the liquid air energy storage subsystem of this embodiment has at least the following advantages:

[0113] The liquid air energy storage subsystem of this invention effectively reduces the footprint and improves the system's safety, environmental friendliness, and efficiency in multiple ways. Specifically, the use of high-pressure solid-phase thermal and cold storage units, compared to atmospheric and low-pressure solid-phase thermal and cold storage, helps to weaken the influence of the thermocline and improve the system's electro-electric conversion efficiency. Placing the high-pressure equipment underground reduces the system's footprint and improves system safety. The underground high-pressure thermal and cold storage unit adopts a "U"-shaped structure, which can better adapt to uneven ground settlement and soil compression, reducing the risk of pipeline damage and improving the system's reliability and safety. Furthermore, the "U"-shaped structure ensures uniform airflow and stable gas-solid heat transfer, which is more in line with the laws of heat conduction and improves the system's heat exchange efficiency. The high-pressure thermal and cold storage unit uses direct heat exchange between air and the thermal and cold storage medium for thermal and cold storage. Compared to indirect heat exchange using circulating air, the system is more efficient. Compared to indirect heat exchange using chemical media such as heat transfer oil, methanol, and propane, it does not use flammable and explosive chemicals, resulting in higher environmental friendliness and safety.

[0114] like Figure 1 and Figure 2 As shown, a specific embodiment of the second aspect of the present invention provides a liquid air energy storage coupling system. This liquid air energy storage coupling system includes a liquid air energy storage subsystem and a biomass gasification subsystem as described in any of the above embodiments. The liquid air energy storage subsystem further includes a turbine unit 630, with the air outlet of the heat storage unit 100 connected to the air inlet of the turbine unit 630 for supplying high-temperature air to the turbine unit 630. The high-temperature air enters the turbine unit 630 to drive a generator to generate electricity and cool down the system. The air outlet of the turbine unit 630 is used to discharge the cooled air. The biomass gasification subsystem includes a biomass gasifier 50; the gasifying agent inlet of the biomass gasifier 50 is connected to the air outlet of the turbine unit 630.

[0115] In this embodiment, since it includes the liquid air energy storage subsystem of any of the above embodiments, it has at least the advantages described above.

[0116] In addition, by connecting the air outlet of the turbine unit 630 to the gasifying agent inlet of the biomass gasifier 50 of the biomass gasification subsystem, the air discharged from the turbine unit 630 can be reused, realizing the resource utilization of clean air in the liquid air energy storage system, improving the system efficiency of the liquid air energy storage system, and solving the problem of low resource utilization rate in both standalone liquid air energy storage systems and liquid air energy storage coupled systems in the prior art.

[0117] Specifically, in the energy storage phase, the air compressor unit 710 compresses ambient temperature and pressure air into high-temperature and high-pressure air. This high-temperature, high-pressure air enters the heat storage unit 100, which stores the heat of compression of the air. The cooled high-pressure air then enters the cold storage unit 200, which pre-cools the compressed air discharged from the heat storage unit 100 to liquefy it. In the energy release phase, the cold storage unit 200 reheats the liquid air. The reheated air then enters the heat storage unit 100, where it reheats the air discharged from the cold storage unit 200 to vaporize it into high-temperature air. This high-temperature air enters the turbine unit 630 to drive the generator and generate electricity. Simultaneously, the cooled air is discharged from the air outlet of the turbine unit 630. Because the air outlet of the turbine unit 630 is connected to the gasifying agent inlet of the biomass gasifier 50, the cooled air enters the biomass gasifier 50.

[0118] like Figure 2 As shown, the heat storage unit 100 further includes heat exchange tubes. The heat exchange medium outlet of the heat exchange tubes is connected to the heat exchange medium inlet of the heat storage component 90, and the heat exchange medium inlet of the heat exchange tubes is connected to the heat exchange medium outlet of the heat storage component 90, forming a heat exchange medium circulation loop. The heat exchange medium enters the heat storage component 90 and exchanges heat with the syngas, increasing the temperature of the heat exchange medium and decreasing the temperature of the syngas. The heat exchange medium then enters the heat exchange tubes of the heat storage unit 100 and exchanges heat with the reheated air discharged from the cold storage unit 200, further heating the air so that the high-temperature air enters the turbine unit 630. This allows for the recovery and utilization of heat from biomass gasification, improving the system efficiency of the liquid air energy storage subsystem. Additionally, the heat exchange medium exchanges heat with the solid-phase heat storage medium in the heat storage chamber 110, allowing the solid-phase heat storage medium to store the heat from the heat exchange medium, further improving the efficiency of the liquid air energy storage subsystem.

[0119] Specifically, the heat storage component 90 includes a heat accumulator 91 and a blower 92. A heat exchange medium circulation loop is formed between the heat accumulator 91 and the heat storage unit 100, and the blower 92 is located in the airflow passage between the heat accumulator 91 and the heat storage unit 100 to supply air to the circulation loop. The syngas inlet of the heat accumulator 91 is connected to the gasifying agent outlet of the biomass gasifier 50, and the syngas outlet of the heat accumulator 91 is used to discharge the cooled syngas. Using air as the heat exchange medium has advantages such as environmental protection, safety, and economy.

[0120] like Figure 1 As shown, in some embodiments, the gasifying agent outlet of the biomass gasifier 50 is connected to the heat exchange medium inlet of the heat exchange tube of the heat storage unit 100, and the heat exchange medium outlet of the heat exchange tube is connected to the syngas storage tank 60. The high-temperature synthesizer discharged from the gasifying agent outlet of the biomass gasifier 50 directly exchanges heat with the solid phase heat storage medium in the heat storage chamber 110, so that the solid phase heat storage medium stores the heat of the synthesizer.

[0121] like Figure 1 and Figure 2 As shown, in some embodiments, the liquid air energy storage coupling system includes a second air inlet pipe 2 and / or a third air inlet pipe 3. The two ends of the second air inlet pipe 2 are respectively connected to the air outlet of the air compressor unit 710 and the gasifying agent inlet of the biomass gasifier 50, and a second switching valve 5 is installed on the second air inlet pipe 2. The two ends of the third air inlet pipe 3 are respectively connected to the cold storage unit 200 and the gasifying agent inlet of the biomass gasifier 50, for conveying reheated air discharged from the cold storage unit 200 to the biomass gasifier 50; a third switching valve 6 is installed on the third air inlet pipe 3.

[0122] In this embodiment, by providing a second air inlet pipe 2, clean air from the air outlet of the air compressor unit 710 can be introduced into the gasifying agent inlet of the biomass gasifier 50, providing gasifying agent for the biomass gasifier 50. By providing a third air inlet pipe 3, rewarmed air discharged from the cold storage unit 200 can be introduced into the gasifying agent inlet of the biomass gasifier 50, providing gasifying agent for the biomass gasifier 50, which can further improve the resource utilization rate of the liquid air energy storage subsystem.

[0123] Furthermore, the air outlet of turbine unit 630 is connected to the gasifying agent inlet of biomass gasifier 50 via a first air inlet pipe 1, and a first switching valve 4 is installed on the first air inlet pipe 1. The air outlet of air compressor unit 710 is connected to the gasifying agent inlet of biomass gasifier 50 via a second air inlet pipe 2, and a second switching valve 5 is installed on the second air inlet pipe 2. The cold storage unit 200 and the gasifying agent inlet of biomass gasifier 50 are connected via a third air inlet pipe 3, and a third switching valve 6 is installed on the third air inlet pipe 3. During the energy storage phase, the second switching valve 5 is opened to supply air to the gasifier using a section of compressed air. During the energy storage and release interval phase, the third switching valve 6 is opened to supply air to the gasifier using the rewarmed air discharged from the cold storage unit 200. During the energy release phase, the first switching valve 4 is opened to supply air to the gasifier using the air from the air outlet of turbine unit 630. In this embodiment, the gasifier is supplied with a continuous and stable gasifying agent by switching valves, thus maintaining a continuous and stable biomass gasification reaction.

[0124] In some embodiments, the liquid air energy storage coupling system further includes a heat storage component 90. The syngas inlet of the heat storage component 90 is connected to the syngas outlet of the biomass gasifier 50, and the syngas outlet of the heat storage component 90 is used to discharge the cooled syngas; the heat storage component 90 is connected to the heat storage unit 100 to form a heat exchange medium circulation loop; the syngas entering the heat storage component 90 is used to heat the heat exchange medium, thereby raising the temperature of the heat exchange medium.

[0125] In this embodiment, a heat storage component 90 is provided, which enables heat exchange between the syngas and the heat exchange medium, thereby lowering the temperature of the syngas and raising the temperature of the heat exchange medium. Simultaneously, the heat storage component 90 and the heat storage unit 100 form a heat exchange medium circulation loop, thus enabling the utilization of the syngas's heat. This not only improves the power generation efficiency of the liquid air energy storage subsystem but also allows for the recovery and utilization of heat from biomass gasification, thereby increasing the energy utilization rate of the biomass gasification subsystem.

[0126] It should be noted that the heat exchange medium can be either a gas or a liquid. Preferably, the heat exchange medium is air.

[0127] Furthermore, the heat storage assembly 90 includes a heat storage unit 91; the heat storage unit 91 has a receiving cavity, a first heat exchange tube, and a second heat exchange tube; the receiving cavity is filled with a solid-phase heat storage medium; the first heat exchange tube and the second heat exchange tube are embedded in the solid-phase heat storage medium, the first heat exchange tube is used to transport syngas, and the second heat exchange tube is used to transport the heat exchange medium. Using a solid-phase heat storage medium to store the heat of the syngas can improve heat exchange efficiency and is safe and reliable.

[0128] Specifically, the solid-phase heat storage medium includes at least one of concrete, rock, gravel, steel, and magnetite.

[0129] like Figures 1 to 4 As shown, in some embodiments, the biomass gasifier 50 is a fluidized bed gasifier. Fluidized bed gasifiers include bubbling fluidized bed gasifiers, circulating fluidized bed gasifiers, or dual fluidized bed gasifiers. Using a fluidized bed gasifier can effectively avoid problems such as bed clogging and scaling associated with fixed bed gasifiers. Furthermore, in a fluidized bed gasifier, the gasifying agent is injected into the bed, forming a large number of gas microbubbles, suspending the material in the gas flow. This provides advantages such as stable operation, low pollutant emissions, short reaction time, and high reaction efficiency. However, fluidized bed gasifiers require a large amount of gas to form the fluidized bed. The integrated system described in this invention, by coupling with a liquid air energy storage subsystem, can effectively solve the problem of the large gas volume required by fluidized bed gasifiers.

[0130] Specifically, the operating temperature of the biomass gasifier 50 is 700~1000℃, and the operating pressure is 0.11~0.15MPa. The temperature of the syngas discharged from the syngas outlet of the biomass gasifier 50 is 100~300℃ lower than the gasification temperature. Depending on the actual conditions of the project site, heat sources such as off-peak electric heating, solar thermal energy, and high-temperature industrial waste heat from smelting plants can be flexibly selected to supply heat to the biomass gasifier 50.

[0131] Furthermore, the biomass gasification subsystem includes a feedstock supply component 70 and a syngas purification component 80. The feedstock supply component 70 supplies biomass feedstock to the biomass gasifier 50. One end of the syngas purification component 80 is connected to the syngas outlet of the biomass gasifier, and the other end is connected to the syngas inlet of the accumulator 91. By setting up the syngas purification component 80, clean syngas can be ensured to be input into the accumulator 91.

[0132] Specifically, the syngas purification assembly 80 includes a cyclone separator 81 and a tar reformer 82. The cyclone separator 81 and the tar reformer 82 are installed on the pipeline between the syngas outlet of the biomass gasifier and the syngas inlet of the accumulator 91, with the cyclone separator 81 located upstream of the tar reformer 82. Biomass feedstock and gasifying agent react at high temperature in biomass gasifier 50. After biomass gasification, the high-temperature syngas produced by the gasifier passes through cyclone separator 81 for ash removal. The inlet temperature of cyclone separator 81 is approximately 700~900℃. The high-temperature syngas after ash removal enters tar reformer 82 for further purification. The temperature of tar reformer 82 is controlled at the optimal reaction temperature of tar reforming, 600~800℃. The purified syngas is cooled and heat is recovered by heat accumulator 91. The cooled and purified syngas can be stored in syngas storage tank 60 for later use; or it can be directly fed into power generation system 7 and / or chemical substance production subsystem 8, improving the utilization rate of syngas from biomass gasification reaction.

[0133] Furthermore, the raw material supply component 70 includes a biomass storage bin 71, a cutting and shaping machine 72, a hopper 73, a belt conveyor 74, a crushing bin 75, and a locking hopper 76. The biomass raw material is stored in the biomass storage bin 71. After being crushed by the cutting and shaping machine 72, the raw material enters the receiving hopper 73 and is then transported to the crushing bin 75 by the belt conveyor. The crushed material is then added to the biomass gasifier 50 through the locking hopper 76.

[0134] like Figure 1 and Figure 2 As shown, the biomass gasification subsystem further includes a syngas storage tank 60; the syngas storage tank 60 is connected to the syngas outlet of the heat storage component 90 and is used to store the cooled syngas. Specifically, the syngas storage tank 60 is connected to the syngas outlet of the heat accumulator 91.

[0135] Furthermore, the liquid air energy storage coupling system also includes a power generation system 7 and / or a chemical substance production subsystem 8; the power generation system 7 is connected to the syngas storage tank 60. The chemical substance production subsystem 8 is connected to the syngas storage tank 60. Specifically, the power generation system 7 includes a steam power generation system 7, a gas power generation system 7, and / or an internal combustion engine power generation system 7. In this embodiment, using the syngas generated from biomass gasification for power generation can significantly improve the energy storage scale and capacity of the energy storage system. Depending on the electricity demand and the required energy storage scale, the remaining biomass syngas can also be used to synthesize chemicals such as methanol and ethanol.

[0136] Specifically, the chemical substances produced by the chemical substance production subsystem 8 include methanol or ethanol.

[0137] In summary, the liquid-air energy storage coupling system of the present invention has the following advantages:

[0138] (1) Integrate biomass gasification power generation or biomass gasification chemical production with liquid air energy storage subsystem to realize the resource utilization of a large amount of clean air in liquid air energy storage subsystem and the heat recovery of high temperature synthesis gas from biomass gasification, thereby improving the round-trip efficiency of liquid air energy storage system and the overall energy utilization efficiency of the entire integrated system.

[0139] (2) The coupling of biomass gasification power generation and liquid air energy storage can significantly improve the energy storage scale and capacity of the energy storage system. At the same time, according to the electricity demand and the demand for energy storage scale, the remaining biomass syngas can also be used to synthesize chemicals such as methanol, which can flexibly control the energy storage scale and enhance the comprehensive energy utilization rate.

[0140] (3) The biomass gasifier adopts a fluidized bed gasifier, which can effectively avoid the problems of bed blockage and scaling caused by using a fixed bed gasifier. It has the advantages of stable operation, low pollutant emissions, short reaction time and high reaction efficiency. At the same time, by coupling with the liquid air energy storage subsystem, the problem of large gas consumption required by the fluidized bed gasifier can be effectively solved.

[0141] (4) Heat recovery from high-temperature biomass syngas is achieved through solid-phase heat storage medium, and heat is reused through circulating air. Compared with the use of liquid-phase heat storage medium, it has advantages such as environmental protection, safety and economy.

[0142] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A liquid air energy storage subsystem, characterized in that, include: The heat storage unit (100) is buried underground; The heat storage unit (100) has a heat storage cavity (110) filled with a solid phase heat storage medium; A cold storage unit (200) is buried underground; the cold storage unit (200) has a cold storage chamber, which is filled with a solid-phase cold storage medium; the heat storage chamber (110) is connected to the cold storage chamber through a second gas supply pipe (810); During the energy storage phase, the heat storage unit (100) is used to store the heat of compression, and the cold storage unit (200) is used to pre-cool the compressed air discharged from the heat storage unit (100) so as to liquefy the compressed air; During the energy release phase, the cold storage unit (200) is used to reheat the liquid air, and the heat storage unit (100) is used to reheat the air discharged from the cold storage unit (200) to vaporize the liquid air. The heat storage chamber (110) includes: The first straight segment (111) has its first end connected to the air passage of the air compressor unit (710); The second straight segment (112) is disposed on one side of the first straight segment (111), and the first end of the second straight segment (112) is connected to the gas passage of the cold storage chamber. The arc segment (113) has two ends connected to the second end of the first straight segment (111) and the second end of the second straight segment (112) respectively, forming the heat storage cavity (110) with a U-shaped structure; wherein the cold storage cavity has the same shape as the heat storage cavity (110).

2. The liquid air energy storage subsystem according to claim 1, characterized in that, The heat storage unit (100) includes: Inner shell (120), the inner shell (120) having the heat storage cavity (110); The outer shell (130) is formed on the outside of the inner shell (120) and forms a filling gap (140) between the outer shell (130) and the inner shell (120); the filling gap (140) is used to contain the heat preservation / cold preservation medium.

3. The liquid air energy storage subsystem according to claim 2, characterized in that, The outer casing (130) has a recess (131) located between the first straight segment (111) and the second straight segment (112).

4. The liquid air energy storage subsystem according to claim 1, characterized in that, The operating temperature of the heat storage unit (100) is -196℃ to 20℃, and the operating pressure is 1.5MPa to 10MPa; the operating temperature of the cold storage unit (200) is 20℃ to 400℃, and the operating pressure is 1.5MPa to 15MPa.

5. The liquid air energy storage subsystem according to claim 1, characterized in that, Also includes: A gas reflux assembly, wherein the inlet end of the gas reflux assembly is used to connect with the outlet gas path of the liquid air storage tank (500), and the outlet end of the gas reflux assembly is used to connect with the inlet gas path of the air compressor unit (710).

6. The liquid air energy storage subsystem according to claim 5, characterized in that, The gas reflux assembly includes: A gas reflux pipe (310) is provided, the inlet end of which is connected to the outlet gas path of the liquid air storage tank (500). A coil (320) is installed inside the cold storage chamber; the inlet end of the coil (320) is connected to the outlet end of the gas reflux pipe (310); A return pipe (330) is provided, the air inlet of which is connected to the air outlet of the coil (320), and the air outlet of the return pipe (330) is connected to the air inlet of the air compressor unit (710). The fifth valve body (340) is disposed in the return pipe (330).

7. The liquid air energy storage subsystem according to any one of claims 1 to 6, characterized in that, Also includes: A pressure-reducing assembly (400) is provided, wherein the liquid inlet of the pressure-reducing assembly (400) is connected to the liquid outlet of the cold storage unit (200); A liquid air storage tank (500) is connected to the outlet of the pressure reducing assembly (400) and is used to store atmospheric pressure liquid air.

8. A liquid air energy storage coupling system, characterized in that, include: The liquid air energy storage subsystem according to any one of claims 1 to 7 further includes a turbine unit (630), wherein the air outlet of the heat storage unit (100) is connected to the air inlet of the turbine unit (630) for supplying high-temperature air to the turbine unit (630), wherein the high-temperature air enters the turbine unit (630) to drive a generator to generate electricity and cool down, and the air outlet of the turbine unit (630) is used to discharge the cooled air; A biomass gasification subsystem, the biomass gasification subsystem including a biomass gasifier (50); The gasifying agent inlet of the biomass gasifier (50) is connected to the air outlet of the turbine unit (630).

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