Liquid air energy storage system coupled with ORC and ARS

Abstract

The utility model discloses a liquid air energy storage system coupled with ORC and ARS, and belongs to the technical field of energy storage and utilization. Comprising an air liquefaction circulation loop unit, an air power generation circulation loop unit, an ORC unit and an ARS unit. According to the system, organic Rankine cycle (ORC) and absorption refrigeration (ARS) are firstly coupled to realize waste heat utilization, and on the basis, a circulation process is added to utilize energy stored by purge high-temperature air behind a gas-liquid separator to realize further energy utilization. Compared with a traditional liquefied air energy storage system, loss in the heat transfer process can be effectively reduced, loss caused by mixing of cold / heat energy of different energy levels is avoided, and the purposes of cold / heat energy graded storage, efficient air compression heat utilization and system efficiency improvement are achieved.

Description

Technical Field

[0001] This utility model belongs to the field of energy storage and utilization technology, specifically relating to a liquid air energy storage system that couples ORC and ARS. Background Technology

[0002] Renewable energy power generation, such as wind and solar power, relies on natural resource conditions and is characterized by intermittent power generation and power fluctuations. Furthermore, issues related to power generation (such as unstable power supply and supply-demand imbalances) and the power grid (such as grid constraints and insufficient peak-shaving capacity) have led to serious problems of wind and solar power curtailment. Therefore, the large-scale grid connection and consumption of renewable energy has a significant impact on the stability of the power system, but it also presents new opportunities for the development of energy storage technology.

[0003] Compared to conventional energy storage technologies, Liquid Air Energy Storage (LAES) does not require large pressurized storage containers, thus overcoming the limitations imposed by geographical location on site selection and construction, making it more suitable for user-side energy storage. LAES technology can not only leverage peak-valley pricing for arbitrage but also effectively regulate peak-valley load differences on the user side to reduce capacity tariffs. Furthermore, it can serve as an emergency power source to improve user-side power reliability. However, existing LAES systems only consider utilizing the waste heat from compression, while the energy lost from the released high-temperature gas is not fully utilized. Utility Model Content

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a liquid air energy storage system that couples ORC and ARS, so as to solve the problem of energy loss due to insufficient utilization of high-temperature gas in the existing technology of liquefied air energy storage.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] An organic Rankine cycle (ORC) and an air liquefaction (ARS) system is provided, comprising an organic Rankine cycle unit, an air liquefaction circulation loop, a liquid air energy release unit, a heat storage unit, and an absorption refrigeration unit.

[0007] The heat storage unit includes a high-temperature heat storage tank, a low-temperature heat storage tank, a high-temperature heat storage tank, a heat exchanger HX1, and a heat exchanger HX2;

[0008] The air liquefaction circulation loop includes several stages of compressors, each compressor being connected to the inlet of a heat exchanger and a high-temperature storage tank; the compressors are electrically driven.

[0009] The liquid air energy release unit comprises several stages of expanders, each of which is connected with an inlet of a heat exchanger and a low-temperature storage tank; the expander drives a generator to generate electricity;

[0010] An outlet of the low-temperature storage tank is connected with a heat exchanger in the air liquefaction circulation loop, an outlet of the high-temperature storage tank is sequentially connected with a heat exchanger HX1 and a heat exchanger HX2, and an outlet of a heat exchanger in the liquid air energy release unit is connected to a connecting pipeline of the high-temperature storage tank and the heat exchanger HX1.

[0011] A heat output pipeline of the HX1 is connected with an organic Rankine cycle unit, and a heat output pipeline of the HX2 is connected with an absorption refrigeration unit.

[0012] Further improvement of the utility model lies in that:

[0013] Preferably, the utility model further comprises a gas-liquid separator, a liquid air storage tank and a heat exchanger eleven.

[0014] A hot side outlet of a last-stage heat exchanger in the air liquefaction circulation loop is connected with an inlet of the gas-liquid separator, a gas outlet of the gas-liquid separator is connected with the air liquefaction circulation loop, a liquid outlet is connected with the liquid air storage tank, and the liquid air storage tank is connected with a cold side inlet of the heat exchanger eleven.

[0015] Preferably, the utility model further comprises a high-pressure heat storage tank and a heat exchanger ten.

[0016] A high-temperature high-pressure input pipeline of the heat exchanger ten is connected with the air liquefaction circulation loop, and a high-temperature high-pressure output pipeline is connected with an inlet of the gas-liquid separator.

[0017] A hot side pipeline of the high-pressure heat storage tank is communicated with a cold side pipeline of the heat exchanger ten, and the cold side pipeline of the high-pressure heat storage tank is communicated with a hot side pipeline of the heat exchanger eleven.

[0018] Preferably, the heat exchanger ten is provided with two high-temperature high-pressure output pipelines, one of which is provided with a first valve, and the other is provided with an expander.

[0019] Preferably, the gas outlet of the gas-liquid separator is connected with the air liquefaction circulation loop through the heat exchanger ten.

[0020] Preferably, an outlet of each compressor in the air liquefaction circulation loop is connected with a hot side pipeline inlet of a heat exchanger, a hot side pipeline outlet of each heat exchanger is connected with an inlet of a next-stage compressor, and a hot side pipeline outlet of a last heat exchanger is connected with the heat exchanger ten.

[0021] A cold side output pipeline of each heat exchanger is connected with an inlet of the high-temperature storage tank.

[0022] Preferably, the inlet of each expander in the liquid air energy release unit is connected with the outlet of the cold side of one heat exchanger, and the inlet of the cold side of each heat exchanger is connected with the outlet of the expander in the previous stage;

[0023] The outlet of the cold side pipeline of the heat exchanger is connected with the inlet of the low-temperature storage tank, and the inlet of the cold side pipeline is connected with the inlet of the high-temperature storage tank.

[0024] Preferably, the organic Rankine cycle unit is connected with the heat output pipeline of the heat exchanger O1, the heat output pipeline of the heat exchanger O1 is connected with the expander O2, the output pipeline of the expander O2 is connected with the hot side pipeline of the cooler O3, and the hot side pipeline of the cooler O3 is output to the heat exchanger O1.

[0025] Preferably, the absorption refrigeration unit is connected with the heat output pipeline of the absorption tower A1 and the heat exchanger HX2, the low-concentration liquid outlet of the absorption tower A1 is connected with the heat exchanger A7, and the gas outlet is connected with the cooler A2.

[0026] Preferably, the heat exchanger A7 is connected with the hot side pipeline of the heat exchanger A5, the hot side pipeline of the cooler A2 is connected with the hot side pipeline inlet of the evaporator A4, and the hot side pipeline outlet of the evaporator A4 is connected with the hot side pipeline inlet of the heat exchanger A5.

[0027] Compared with the prior art, the liquid air energy storage system has the following beneficial effects:

[0028] The utility model discloses a novel coupling ORC and ARS's liquid air energy storage system, including air liquefaction circulating loop unit, air power generation circulating loop unit, ORC unit and ARS unit. At the time period of electricity low, extra power drives air liquefaction circulating and obtains liquid air, and the air compression heat is stored in stages simultaneously, at the time period of electricity peak, air power generation circulating works: liquid air is after pressurization, low temperature cold quantity is stored in stages, enters air turbine unit expansion power generation, consumes part air compression heat, ORC unit and ARS unit are connected with air liquefaction circulating loop unit to utilize the remaining low grade heat energy, and the extra air compression heat can drive organic Rankine cycle to obtain additional electric quantity, also can drive absorption refrigeration cycle to obtain low temperature cold quantity and be used for liquefied air. The system first couples organic Rankine cycle ORC and absorption refrigeration ARS to realize the utilization of waste heat, and on this basis, adds the circulating process to utilize the energy of the relaxed high temperature air after the gas-liquid separator to realize the further utilization of energy. Compared with the traditional liquefied air energy storage system, can effectively reduce the heat transfer process's exergy loss, and avoids the exergy loss caused by the mixing of different energy levels cold / heat energy, realizes cold / heat energy graded storage, air compression heat efficient utilization and the purpose of improving system efficiency. The utility model has the following advantages:

[0029] (1) The system is a new type of LAES system, which fully utilizes all waste heat released in the charging stage of the LAES by combining the LAES with an organic Rankine cycle and an absorption refrigeration system, and improves the cycle efficiency of the system.

[0030] (2) The organic Rankine cycle (ORC) is a heat cycle system which uses an organic working fluid instead of water vapor as a working fluid to generate electricity from a low-temperature heat source. As a low-temperature heat energy utilization technology, the organic Rankine cycle is widely used in the fields of geothermal energy, waste heat utilization, solar energy and the like. On this basis, an absorption refrigeration system is additionally arranged to realize the combination of cogeneration and absorption refrigeration. In this combined mode, the waste heat generated in the power generation process can drive the absorption refrigeration, and the waste heat can be recovered to improve the energy utilization rate.

[0031] (3) The absorption refrigeration unit in the utility model makes full use of the surplus high-temperature heat conducting oil in the system to obtain low-temperature cold energy, which is used for air liquefaction circulation to improve the liquefaction rate of the system and further improve the overall efficiency of the system.

[0032] (4) The organic Rankine cycle in the utility model collects the waste heat of the heat conducting oil and the waste heat of the exhaust gas after the stage to obtain additional power generation capacity, which can significantly increase the power generation capacity of the system and improve the overall efficiency of the system.

[0033] (5) The surplus air compression heat utilization unit (including ORC+ARS) uses the surplus air compression heat in the air compression heat grading storage unit, and does not affect the power generation capacity of the air turbine unit. The surplus air compression heat utilization unit can use the surplus air compression heat to drive the absorption refrigeration cycle to obtain low-temperature cold energy, which is used for air liquefaction circulation to improve the liquefaction rate of the system. The surplus air compression heat utilization unit can use the surplus air compression heat to drive the Rankine cycle to obtain additional power generation capacity to improve the power generation capacity of the system. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 It is a structural schematic view of the liquid air energy storage system coupled with the ORC and the ARS.

[0035] Among them: 1, compressor one;2, compressor two;3, compressor three;4, compressor four;5, expander one;6, expander two;7, expander three;8, expander four;9, heat exchanger one, 10, heat exchanger two;11, heat exchanger three;12, heat exchanger four;13, heat exchanger five;14, heat exchanger six;15, heat exchanger seven;16, heat exchanger eight;17, heat exchanger ten;18, first valve;19, gas-liquid separator;20, first expander;21, liquid air storage tank;22, liquid pump;23, heat exchanger eleven;24, high-pressure heat storage tank;25, low-temperature storage tank;26, high-temperature storage tank.

[0036] A1, absorption column; A2, cooler; A3, valve; A4, evaporator; A5, heat exchanger; A6, pump; A7, heat exchanger; A8, valve; HX1, heat exchanger; HX2, heat exchanger.

[0037] O1, heat exchanger; O2, expander; O3, cooler; O4, pump. DETAILED DESCRIPTION

[0038] The utility model will be described in further detail below in combination with the drawings:

[0039] The embodiments of the utility model are described in detail below, and the examples of the embodiments are shown in the drawings, wherein the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the utility model and cannot be understood as a limitation of the utility model.

[0040] The ORC in the utility model is Organic Rankine Cycle, which refers to an organic Rankine cycle unit; and the ARS is Absorption Refrigeration, which refers to absorption refrigeration.

[0041] The utility model discloses a kind of liquid air energy storage systems coupling ORC and ARS, including air liquefaction circulation loop unit, liquid air energy release unit, heat storage unit, ORC unit and ARS unit.

[0042] Further, the air compressor set comprises one or more compressors and coolers; and the air turbine set comprises one or more turbines and heaters.

[0043] Further, the medium-grade cold energy grading storage unit, the high-grade cold energy grading storage unit and the air compression heat grading storage unit each comprise one or more stages, each stage uses latent heat or sensible heat energy storage material in a corresponding temperature zone, and each stage uses thermal insulation material for thermal insulation.

[0044] The air liquefaction cycle loop unit comprises a heat exchanger 9, a heat exchanger 10, a heat exchanger 11, a heat exchanger 12, a heat exchanger 17, a compressor 1, a compressor 2, a compressor 3, a compressor 4, a first expander 20, a gas-liquid separator 19 and a liquid air storage tank 21. The compressor 1, the compressor 2, the compressor 3 and the compressor 4 form a compressor set, the heat exchanger 9 is arranged between the air pipeline of the compressor 1 and the compressor 2, the heat exchanger 10 is arranged between the air pipeline of the compressor 2 and the compressor 3, the heat exchanger 11 is arranged between the air pipeline of the compressor 3 and the compressor 4, and the heat exchanger 12 is arranged between the air pipeline of the compressor 4 and the heat exchanger 17. The compressor 1, the compressor 2, the compressor 3 and the compressor 4 are connected to the same motor and are powered by the motor.

[0045] The heat exchanger 17 is provided with two air inlets and two high-pressure high-temperature air output pipelines as a heat source of the heat exchanger 17; an expander 20 is arranged on one high-temperature high-pressure air output pipeline, a valve 18 is arranged on one high-temperature high-pressure output pipeline, and both high-temperature high-pressure output pipelines lead to the inlet of the gas-liquid separator; the heat exchanger 17 is provided with two cold side pipelines, one cold side pipeline is in communication with the gas outlet of the gas-liquid separator 19 and flows to the inlet of the compressor 3, and the other cold side pipeline is in communication with the outlet of the high-pressure heat storage tank 24 and flows to the inlet of the high-pressure heat storage tank 24. This part heats the gas output from the gas-liquid separator 19 by the steam output from 12 as a heat source, and stores heat in the high-pressure heat storage tank 24 by R123fa. The heat exchanger 17 is an inter-stage low-temperature heat exchange oil absorption inter-stage cooler.

[0046] The liquid air energy release unit comprises a liquid pump 22, a heat exchanger 13, a heat exchanger 14, a heat exchanger 15, a heat exchanger 16, a heat exchanger 23, an expander 5, an expander 6, an expander 7 and an expander 8; the output port of the liquid pump 22 is connected with the output port of the liquid air storage tank 21, the output port of the liquid pump 22 is connected with the lower side input port of the heat exchanger 23, the heat exchanger 23, the heat exchanger 16, the expander 8, the heat exchanger 15, the expander 7, the heat exchanger 14, the expander 6, the heat exchanger 13 and the expander 5 are connected in sequence; the expander 5, the expander 6, the expander 7 and the expander 8 are connected with a common generator G.

[0047] The heat storage unit comprises a high-pressure heat storage tank 24, a high-temperature storage tank 26, a low-temperature storage tank 25, a heat exchanger HX1 and a heat exchanger HX2; the upper input port of the high-temperature heat storage tank 24 is connected with the lower output port of the heat exchanger 17, the upper output port of the high-temperature heat storage tank 24 is connected with the lower input port of the heat exchanger 17, the lower input port of the high-temperature heat storage tank 24 is connected with the upper output port of the heat exchanger 23, the lower output port of the high-temperature heat storage tank 24 is connected with the upper input port of the heat exchanger 23, the input port of the high-temperature storage tank 26 is connected with the lower output ports of the heat exchanger one 9, the heat exchanger two 10, the heat exchanger three 11 and the heat exchanger four 12, the output port of the high-temperature storage tank 26 is connected with the upper input ports of the heat exchanger eight 16, the heat exchanger seven 15, the heat exchanger six 14 and the heat exchanger five 13, the output port of the high-temperature storage tank 26 is connected with the input port of the heat exchanger HX1, the output port of the heat exchanger HX1 is connected with the input port of the heat exchanger HX2.

[0048] The ORC unit comprises a cooler O3, a working fluid pump O4, a heat exchanger O1 and a working fluid expander O2; the output port of the cooler O3 is connected with the input port of the working fluid pump O4, the cold side inlet of the heat exchanger O1 is connected with the output port of the working fluid pump O4, the cold side outlet of the heat exchanger O1 is connected with the input port of the working fluid expander O2, and the hot side inlet of the heat exchanger O1 is connected with the outlet of the heat exchanger HX1; the fluid output port of the working fluid expander O2 is connected with the hot side input port of the cooler O3, and the hot side output port of the cooler O3 is connected with the working fluid pump O4. In this process, the heat of HX1 flows to the heat exchanger O1, the heat is exchanged to the ORC system through the heat exchanger O1, flows to the working fluid pump O4, and the cooler O3 collects the heat in the ORC system and outputs.

[0049] The ARS unit includes a cooler A2, a valve A3, an evaporator A4, a heat exchanger A5, a solution pump A6, a heat exchanger A7, and an absorption tower A1; the absorption tower A1 is provided with a liquid inlet, a liquid outlet, and a steam outlet, the liquid outlet is connected with the cold side inlet of the heat exchanger A7, the cold side outlet of the heat exchanger A7 is connected with the liquid inlet of the absorption tower A1; the steam outlet of the absorption tower A1 is connected with the hot side input port of the cooler A2, the absorption tower A1 is further provided with a heat source inlet, which is communicated with the outlet of HX2; the hot side output port of the cooler A2 is connected with the input port of the valve A3, the cold side of the cooler A2 is connected with a cooling water for cooling the steam in the cooler A2; the output port of the valve A3 is connected with the hot side input port of the evaporator A4, the hot side output port of the evaporator A4 is connected with the cold side input port of the heat exchanger A5, the cold side outlet of the heat exchanger A5 is connected with the inlet of the pump A6, and the deep cooling water is output from the heat exchanger after heat release; the hot side inlet of the heat exchanger is communicated with the outlet of the valve 8, and the hot side outlet is communicated with the inlet of the solution pump A6; the output port of the solution pump A6 is connected with the cold side input port of the heat exchanger A7, and the cold side output port of the heat exchanger A7 is connected with the input port of the absorption tower A1; the lower output port of the absorption tower A1 is connected with the hot side input port of the heat exchanger A7, the hot side output port of the heat exchanger A7 is connected with the input port of the valve A8, the output port of the valve A8 is connected with the upper input port of the heat exchanger A5, and the right input port of the absorption tower A1 is connected with the output end of the heat exchanger HX2.

[0050] The cold side inlets of the heat exchanger one 9, the heat exchanger two 10, the heat exchanger three 11, and the heat exchanger four 12 are connected with the outlet of the low-temperature storage tank 25, and the cold side outlets are connected with the inlet of the high-temperature storage tank 26; from the heat exchanger one 9 to the heat exchanger four 12, the hot side inlets of the four heat exchangers are respectively connected with the compressor one 1, the compressor two 2, the compressor three 3, and the compressor four 4, and the hot side outlets of the four heat exchangers are sequentially connected to the compressor two 2, the compressor three 3, the compressor four 4, and the flow divider 27; the four heat exchangers are used to transfer the heat of the compressor set to the high-temperature storage tank.

[0051] The cold side inlet of the heat exchanger eleven 23 is connected with the outlet of the liquid pump 22, the cold side outlet of the heat exchanger eleven 23 is connected with the cold side inlet of the heat exchanger eight 16, and the hot side inlet is connected with the hot side outlet of the high-pressure heat storage pipe 24; the heat exchanger eleven 23 is used to transfer the heat of the high-pressure heat storage tank 24 to the air flow before the expander set.

[0052] The cold side inlets of heat exchangers five 13 to eight 16 are connected to the cold side outlets of expander two 6, expander three 7, expander four 8 and heat exchanger eleven 23 respectively, and the cold side outlets of heat exchangers five 13 to eight 16 are connected to expander one 5, expander two 6, expander three 7 and expander four 8 in turn respectively, the hot side inlets are connected to the outlet of high temperature storage tank 26, and the hot side outlets are connected to the inlet of low temperature storage tank 25, and heat exchangers five 13 to eight 16 are used for transferring heat of high temperature storage tank 26 to expander group.

[0053] The cold side inlet of HX1 is connected to the hot side outlet of heat exchanger O1, the cold side outlet is connected to the hot side inlet of heat exchanger O1, the hot side inlet of HX1 is connected to the outlet of high temperature storage tank 26, and the hot side outlet of HX1 is connected to the hot side inlet of HX2; HX1 is used for transferring waste heat in the high temperature storage tank to the ORC system.

[0054] The cold side inlet of HX2 is connected to the hot side outlet of absorption tower A1, the cold side outlet is connected to the hot side inlet of absorption tower A1, and the hot side inlet is connected to the hot side outlet of HX1; HX2 is used for transferring waste heat in the high temperature storage tank 26 to the ARS system.

[0055] The cold side of cooler A2 is used for circulating cooling water, the hot side inlet is connected to the outlet of absorption tower A1, and the hot side outlet is connected to valve A3; cooler A2 is used for transferring heat of the ARS system to the cooling water.

[0056] The cold side inlet of heat exchanger A7 is connected to pump A6, the cold side outlet is connected to the inlet of absorption tower A1, the hot side inlet of heat exchanger A7 is connected to the outlet of absorption tower A1, and the hot side outlet is connected to valve A8; heat exchanger A7 is used for transferring heat of absorption tower A1 to cold energy product.

[0057] The cold side inlet of heat exchanger A5 is connected to cold energy product, the cold side outlet is connected to cold energy product, the hot side inlet is connected to the outlet of evaporator A4 and valve A8 respectively, and the hot side outlet is connected to pump A6; heat exchanger A5 is used for transferring heat of the ARS system to cold energy product.

[0058] The cold side of evaporator A4 is used for circulating cooling water, the hot side inlet is connected to valve A3, and the hot side outlet is connected to the hot side outlet of heat exchanger A5; evaporator A4 is used for transferring heat of the ARS system to the cooling water.

[0059] The cold side of cooler O3 is used for circulating cold energy product, the hot side inlet is connected to expander O2, and the hot side outlet is connected to pump O4; heat exchanger O3 is used for transferring heat of the ORC system to cold energy product.

[0060] In some embodiments of the utility model, the heat exchanger one 9, heat exchanger two 10, heat exchanger three 11, heat exchanger four 12, heat exchanger six 13, heat exchanger seven 14, heat exchanger eight 15, heat exchanger nine 16 all include air pipeline, cooling water pipeline, in particular, heat exchanger ten 17, heat exchanger ten 23 include air pipeline, R123fa pipeline, and each heat exchanger corresponding pipeline is connected in turn.

[0061] The circulating working medium of the organic Rankine cycle and the heat storage subsystem is R123fa, and the circulating working medium of the ARS unit is ammonia gas and ammonia water solution.

[0062] A working method of a liquid air energy storage system coupled with ORC and ARS, comprising the following steps:

[0063] S1, the compressor set consumes electric energy to compress the purified air to a high temperature and high pressure state, and the high pressure air is again flashed and cooled in the gas-liquid separator 19. The heat of the compressed air in the heat exchanger 17 is stored in the high temperature heat storage tank 24 as a heat exchange medium. The high pressure low temperature air is liquefied through the throttle valve and stored in the liquid air storage tank 21. The air not liquefied continues to circulate to the second stage compressor through the gas-liquid separator 19, and then reenters the process.

[0064] S2, at the same time of S1 operation, the ORC subsystem inside works simultaneously, the working fluid is first pumped to a high pressure state, then heated to a saturated state in the heat exchanger O1 by the residual compression heat stored in the flue, and expanded in the expander O2 of the ORC to generate electricity, and the working fluid flowing out of the expander O2 is condensed into a liquid state in the cooler O3, starting the next cycle. The outlet stream temperature of the cooler O3 in the ORC subsystem is about 100 DEG C, which can be effectively used for regional cooling and heating.

[0065] S3, at the same time of S1 operation, the ARS subsystem inside works simultaneously, and the liquid ammonia water of a specific concentration is pumped to a high pressure state. Subsequently, the liquid mixture is further heated by the outlet air from the ORC subsystem until it reaches a liquid-vapor state. In the absorption tower A1, the mixture is separated into a low concentration liquid stream and a high concentration vapor stream. The low concentration liquid stream is heated by the original working fluid through the heat exchanger A7, and then returns to the absorption tower A1. On the other hand, the liquid working fluid passes through the valve A8 process to make it reach a low temperature state, and evaporates together with the cooling water of the evaporator. During the evaporation process in the ARS, the cold energy of ammonia-water is transferred to the appropriate working medium to provide cooling capacity. Finally, the high concentration ammonia water returns to the absorption tower A1, where it mixes with the low concentration water stream and condenses into a vapor state, starting the next cycle.

[0066] S4, the liquid gas in the liquid air tank 21 is pressurized by a liquid pump, and vaporizes after absorbing the heat of the high-temperature heat storage tank 24 in the heat exchanger 23. The low-temperature high-pressure air is heated into high-temperature high-pressure air in the reheater. The high-temperature heat-conducting oil releases heat in the reheater and is stored in the low-temperature heat storage tank. Finally, the high-temperature high-pressure air enters the expander set to do work, driving the generator to generate electricity.

[0067] The inlet air pressure of the compressor set of the air liquefaction circulating loop unit is 0.101 MPa, and the outlet air pressure is 18.3 MPa.

[0068] The inlet liquid air pressure of the expander set of the liquid air energy release unit is 7.5 MPa, and the outlet air pressure is 0.101 MPa.

[0069] Preferably, the air liquefaction cycle can use air or nitrogen as the working medium; the high-grade cold energy grading storage unit can use propane or air as the heat transfer fluid; the medium-grade cold energy grading storage unit can use methanol or air as the heat transfer fluid; the air compression heat grading storage unit can use heat-conducting oil or air as the heat transfer fluid; the working medium expander can use R134A or R32 as the working medium; the first refrigeration compressor can use R134A or R410A as the normal-temperature refrigerant; the second refrigeration compressor can use R508B or R23 as the ultra-low-temperature refrigeration working medium; the absorber and the regenerator can use NH3-H2O or LiBr-H2O as the solution

[0070] In the description of the utility model, it is understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the utility model and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the utility model.In addition, the features limited as "first" and "second" can explicitly or implicitly include one or more of the features. In the description of the utility model, unless otherwise specified, the meaning of "multiple" is two or more. In the description of the utility model, the "upper" or "lower" of the first feature in the second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them.

[0071] In the description of the utility model, first feature is in the second feature "on", "above" and "on" include first feature is in the second feature directly above and oblique, or just indicate that the horizontal height of first feature is higher than second feature.

[0072] In the description of the utility model, it is needful to explain, unless another explicit stipulation and limitation, the term "installation", "link", "connection" should do broad sense understanding, for example, can be fixed connection, also can be detachable connection, or integrally connected;Can be mechanical connection, also can be electrical connection;Can be directly connected, also can pass through intermediate medium indirectly connected, can be two element inside the intercommunication.For ordinary skilled person in the art, the specific meaning of the above-mentioned term in the utility model can be understood according to the specific circumstances.

[0073] In the description of the utility model, the description of reference terms "one embodiment", "some embodiments", "schematic embodiment", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are contained in at least one embodiment or example of the utility model.In the description of the utility model, the schematic representation of the above-mentioned terms does not necessarily refer to the same embodiment or example.Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0074] Although the embodiments of the utility model have been shown and described, those skilled in the art can understand that various changes, modifications, replacements and variations can be made to these embodiments without departing from the principles and purposes of the utility model, and the scope of the utility model is defined by the claims and its equivalents.

[0075] The above only is the preferred embodiment of the utility model, and does not limit the utility model, and any modification, equivalent replacement, improvement, etc.were made in the spirit and principle of the utility model, should be included in the protection scope of the utility model.

Claims

1. A liquid air energy storage system coupled to an ORC and an ARS, characterized in that, The system comprises an organic Rankine cycle unit, an air liquefaction cycle loop, a liquid air energy release unit, a heat storage unit and an absorption refrigeration unit. The heat storage unit comprises a high-pressure heat storage tank (24), a low-temperature storage tank (25), a high-temperature storage tank (26), a heat exchanger HX1 and a heat exchanger HX2. The air liquefaction cycle loop comprises several stages of compressors, each of which is connected to a heat exchanger and an inlet of a high-temperature storage tank (26); the compressors are driven by electricity. The liquid air energy release unit comprises several stages of expanders, each of which is connected to a heat exchanger and an inlet of a low-temperature storage tank (25); the expanders drive generators to generate electricity. An outlet of the low-temperature storage tank (25) is connected to a heat exchanger in the air liquefaction cycle loop, and an outlet of the high-temperature storage tank (26) is sequentially connected to the heat exchanger HX1 and the heat exchanger HX2; an outlet of a heat exchanger in the liquid air energy release unit is connected to a connecting pipeline of the high-temperature storage tank (26) and the heat exchanger HX1. A heat output pipeline of the HX1 is connected to the organic Rankine cycle unit, and a heat output pipeline of the HX2 is connected to the absorption refrigeration unit.

2. A liquid air energy storage system coupled with ORC and ARS according to claim 1, characterized in that, The system further comprises a gas-liquid separator (19), a liquid air storage tank (21) and a heat exchanger XI (23). A hot side outlet of a last-stage heat exchanger in the air liquefaction cycle loop is connected to an inlet of the gas-liquid separator (19), a gas outlet of the gas-liquid separator (19) is connected to the air liquefaction cycle loop, a liquid outlet is connected to the liquid air storage tank (21), and the liquid air storage tank (21) is connected to a cold side inlet of the heat exchanger XI (23).

3. A liquid air energy storage system coupled with ORC and ARS according to claim 2, wherein, The system further comprises a heat exchanger X (17). A high-temperature and high-pressure input pipeline of the heat exchanger X (17) is connected to the air liquefaction cycle loop, and a high-temperature and high-pressure output pipeline is connected to an inlet of the gas-liquid separator (19). A hot side pipeline of the high-pressure heat storage tank (24) is in communication with a cold side pipeline of the heat exchanger X (17), and a cold side pipeline of the high-pressure heat storage tank (24) is in communication with a hot side pipeline of the heat exchanger XI (23).

4. A liquid air energy storage system coupled with ORC and ARS according to claim 3, wherein, The heat exchanger X (17) is provided with two high-temperature and high-pressure output pipelines, one of which is provided with a first valve (18), and the other of which is provided with an expander (20).

5. A liquid air energy storage system coupled with ORC and ARS according to claim 3, wherein, A gas outlet of the gas-liquid separator (19) is connected to the air liquefaction cycle loop through the heat exchanger X (17).

6. A liquid air energy storage system coupled with ORC and ARS according to claim 3, wherein, An outlet of each compressor in the air liquefaction cycle loop is connected to a hot side pipeline inlet of a heat exchanger, a hot side pipeline outlet of each heat exchanger is connected to an inlet of a next-stage compressor, and a hot side pipeline outlet of a last-stage heat exchanger is connected to the heat exchanger X (17). A cold side output pipeline of each heat exchanger is connected to an inlet of the high-temperature storage tank (26).

7. A liquid air energy storage system coupled with ORC and ARS according to claim 1, wherein, An inlet of each expander in the liquid air energy release unit is connected to a cold side outlet of a heat exchanger, a cold side inlet of each heat exchanger is connected to an outlet of a previous-stage expander. A cold side pipeline outlet of the heat exchanger is connected to an inlet of the low-temperature storage tank (25), and a cold side pipeline inlet is connected to an inlet of the high-temperature storage tank (26).

8. A liquid air energy storage system coupled with ORC and ARS according to claim 1, wherein, The organic Rankine cycle unit is connected through the heat output pipeline of the heat exchanger O1 and the heat exchanger HX1, the heat output pipeline of the heat exchanger O1 is connected with the expander O2, the output pipeline of the expander O2 is connected with the hot side pipeline of the cooler O3, and the hot side pipeline of the cooler O3 is output to the heat exchanger O1.

9. A liquid air energy storage system coupled with ORC and ARS according to claim 1, wherein, The absorption refrigeration unit is connected through the heat output pipeline of the absorption tower A1 and the heat exchanger HX2, the low-concentration liquid outlet of the absorption tower A1 is connected with the heat exchanger A7, and the gas outlet is connected with the cooler A2.

10. A liquid air energy storage system coupled with ORC and ARS according to claim 9, wherein, The heat exchanger A7 is connected with the hot side pipeline of the heat exchanger A5, the hot side pipeline of the cooler A2 is connected with the hot side pipeline inlet of the evaporator A4, and the hot side pipeline outlet of the evaporator A4 and the hot side pipeline inlet of the heat exchanger A5 are connected.

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