A method and device for absorption refrigeration by coupling the principle of reverse electrodialysis

Abstract

A kind of coupling reverse electrodialysis principle's de-electricity absorption refrigeration method and device, including heat subsystem, absorption refrigeration system ARS subsystem, reverse electrodialysis RED subsystem.ARs based on waste heat absorption refrigeration method converts low-grade heat into cold, including refrigerant cycle and solution cycle, the working solution in generator is parsed into liquid refrigerant vapor under low-grade heat energy heating, throttling after entering evaporator completes refrigerant cycle, and makes cold quantity.The remaining working solution in generator enters absorber after cooling and pressure reduction.Cold vapor from evaporator enters absorber, is absorbed by concentrated solution from generator, and concentrated solution becomes dilute solution and returns to generator, is regenerated into concentrated solution and cold vapor under low-grade heat source heating, and completes cycle.The main driving force in cycle process is external input heat, and ARS cannot be independently operated without power grid.Properly increase the solution cycle and regeneration capacity of original ARS, and connect RED again, to convert solution chemical potential energy into electric energy to power refrigerating unit.The present application can realize low-grade heat energy fully, efficiently and continuously, and refrigerating machine is completely independent of external power supply, and system is safe and reliable.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of refrigeration and air conditioning, and relates to a desorption type absorption refrigeration method and device coupled with the principle of reverse electrodialysis. BACKGROUND

[0002] In the refrigeration and air conditioning industry, absorption refrigeration is driven by low-grade heat energy to achieve refrigeration, and has many advantages compared with refrigerators driven by electric energy. Since it operates in a vacuum state, it is safer and more reliable, has fewer moving parts, operates quietly, is driven by heat energy, saves electricity consumption, and uses working substances that are conducive to meeting environmental protection requirements. In an absorption refrigeration system (ARS), commonly used working pairs include H2O-LiBr (lithium bromide), NH3-H2O, and H2O-LiBr. In the H2O-LiBr working pair, water is used as a refrigerant, and a lithium bromide solution is used as an absorbent. The strong water vapor absorption capacity of lithium bromide is used to make the refrigerant water circulate in a closed system through the concentration and dilution solution generation and absorption processes. The refrigerant water is evaporated and absorbs heat to produce cold energy in a low-pressure vacuum environment, and the working solution is regenerated under the drive of a heat source. Lithium bromide absorption refrigerators are widely used in the industrial field in China, which alleviates the problem of electricity consumption, solves the problem of waste heat recovery and utilization, and meets the needs of production development. However, in the operation process of the absorption refrigerator, the solution pump, refrigerant pump, air extraction device and control system provided by the system still need external input of electric energy. For example, a 11630kW absorption refrigerator consumes 87600 degrees of electricity per year (calculated based on 5 months of annual operation and 20 hours per day), and if this part of the electricity consumption can be reduced, a large amount of energy consumption can be saved.

[0003] The world environmental problems are increasingly prominent, and the energy resource shortage is increasingly serious, which is an important problem to be solved urgently in the economic development of the world. There are a large amount of low-grade heat energy in industrial production and nature, such as industrial waste heat, solar energy, geothermal energy and the like, if which is utilized reasonably, energy can be saved and environmental pollution can be reduced. Although the low-grade heat energy can be used as a heat source in the above-mentioned absorption refrigeration field, it is considered to be affected by seasonal limitation, many studies propose to convert the low-grade heat energy into electric energy continuously. At present, the low-grade heat energy is mainly used for power generation by using the "heat-work" conversion technology, such as organic Rankine cycle technology and the like, but these "heat-work" conversion technologies have many defects, such as high requirements for the characteristics of low-grade heat energy and working medium and the like, so that the application thereof is limited in the recycling of low-grade heat energy in the actual application. In recent years, the "RED heat engine" combining the solution heat separation technology and the reverse electrodialysis (RED) salt difference power generation technology emerges as the times require, the core of which is composed of a solution heat regeneration subsystem and a RED stack subsystem, and the low-grade heat energy (≥60℃) can be first converted into the chemical potential energy between the concentrated and dilute solutions, and then the chemical potential energy of the working solution can be converted into electric energy.

[0004] The ARS and the RED system are coupled, the low-grade heat source is used to drive the RED heat engine to convert the low-grade heat energy into the chemical potential energy between the working solutions, and then the chemical potential energy is converted into electric energy, which is delivered to the above-mentioned electric equipment equipped with the ARS, so that the ARS can be completely "de-electric" operated. SUMMARY

[0005] In view of the problems in the prior art, the application provides a de-electric absorption refrigeration method coupled with the reverse electrodialysis principle. The basic technical principle is as follows:

[0006] The ARS subsystem is used to convert low-grade heat into cold energy based on the absorption refrigeration method. The ARS subsystem mainly includes a refrigerant cycle and a solution cycle. The working solution in the generator is resolved into refrigerant vapor under the heating of low-grade heat energy. The refrigerant vapor is converted into liquid refrigerant after the condenser, and then enters the evaporator to absorb heat and evaporate after throttling, completing the refrigerant cycle and producing cold energy. The remaining working solution in the generator increases in concentration, and after cooling and decompression, enters the absorber. The refrigerant vapor flows out of the evaporator and enters the absorber, and is absorbed by the concentrated solution from the generator. Then the concentrated solution becomes a dilute solution and returns to the generator, and is regenerated into a concentrated solution and refrigerant vapor under the heating of low-grade heat source, completing the cycle. In this cycle process, the main driving force is the heat input from the outside, but the solution pump, control system and the like still need to consume a certain amount of electric energy, and the ARS system cannot be operated independently from the power grid. In the working process of the ARS system, the working solution has obvious salt gradient in different states. Based on the principle of reverse electrodialysis, the salt difference between part of the concentrated and dilute solutions can be converted into electric energy. Therefore, by appropriately increasing the solution circulation and regeneration capacity of the original ARS system and connecting the RED subsystem, the chemical potential energy of the solution can be converted into electric energy, and further used to power the absorption refrigeration unit.

[0007] In order to achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0008] A decoupled absorption refrigeration system coupled with reverse electrodialysis principle, the main components include a generator, an absorber, a condenser, an evaporator, two solution heat exchangers, a RED stack, two absorption liquid pumps, a refrigerant pump, a concentrated solution pump, a dilute solution pump, a waste liquid pump, an electrode liquid circulating pump, a concentrated solution storage tank, a dilute solution storage tank, a waste liquid recovery storage tank, a power storage device, a solution switching valve, three throttling devices, an air extraction device and a main control system. The system is driven by low-grade heat energy to realize "heat-electricity" conversion and continuously provide power for the absorption refrigeration machine. The whole system is composed of three subsystems: a thermal subsystem, a reverse electrodialysis (RED) subsystem and an absorption refrigeration system (ARS) subsystem.

[0009] The heat subsystem is composed of generator 1, condenser 2, dilute solution storage tank 12, concentrated solution storage tank 13, waste liquid recovery storage tank 14, dilute solution pump 15, concentrated solution pump 16, waste liquid pump 17, solution switching valve 23, throttling device 2 26 and solution heat exchanger 2 28, and each device is connected by pipeline. The ARS subsystem is composed of generator 1, condenser 2, absorption liquid pump 1 3, solution heat exchanger 1 4, absorption liquid pump 2 5, absorber 6, refrigerant pump 7, evaporator 8, throttling device 1 9 and throttling device 3 27. The RED subsystem is mainly composed of anode 19, cathode 20, interlaced cation exchange membrane 21, anion exchange membrane 22, end plate 24, anode chamber and cathode chamber separated by end plate 24, anode 19, cathode 20 and two pieces of cation exchange membrane 21 at both ends, interlaced dilute solution chamber and concentrated solution chamber separated by interlaced anion exchange membrane 22 and cation exchange membrane 21. The electrode liquid between the cathode and anode chambers flows in the external circulation of the RED stack under the drive of the electrode liquid circulating pump 25; the generated electric energy of the RED subsystem is stored in the power storage device 18. Specifically:

[0010] The generator 1 in the heat subsystem is a specially designed generator, which is composed of left and right chambers that do not affect each other. The left chamber is used to drive the operation of the ARS system, and the right chamber is used to drive the operation of the RED subsystem. The external low-grade heat source is divided into two branches, which enter the left and right chambers through pipelines. The left chamber of the generator 1 is pre-placed with a dilute solution, and the right chamber is pre-placed with an intermediate concentration solution. The solution concentrations in the left and right chambers of the generator are different. The condenser 2 is also composed of left and right chambers that do not affect each other. The left chamber of the generator 1 is connected to the left chamber of the condenser 2 through a pipeline, and the right chamber of the generator 1 is connected to the right chamber of the condenser 2 through a pipeline. The left chamber of the condenser 2 is connected to the evaporator 8 through a pipeline, and a throttling device 9 is arranged on the pipeline. A refrigerant pump 7 pumps the refrigerant in the evaporator 8 into a spraying device. The right chamber of the condenser 2 is connected to a dilute solution storage tank 12 through a pipeline. The outlet of the right chamber of the generator 1 is connected to a solution heat exchanger 2 8 through a pipeline, and the solution heat exchanger 2 8 is connected to a concentrated solution storage tank 13. The inlet of the right chamber of the generator 1 is connected to the outlet of a waste liquid recovery storage tank 14 through a pipeline, and a waste liquid pump 17, a throttling device 2 6, and a solution heat exchanger 2 8 are arranged on the pipeline. The left chamber of the generator 1 is connected to an absorber 6. An absorbing liquid pump 2 5 pumps the concentrated solution in the left chamber of the generator 1 into a solution heat exchanger 1 4, and the solution heat exchanger is connected to the absorber 6. A throttling device 2 7 is arranged on the pipeline. The absorber 6 dilutes the concentrated solution, and an absorbing liquid pump 1 3 pumps the dilute solution into the solution heat exchanger 1 4. An air extraction device 1 0 is connected to the absorber 6 through a pipeline. A solution switching valve 2 3 is arranged on the connecting pipeline between the concentrated solution storage tank 1 3 and the dilute solution storage tank 1 2. The outlets of the concentrated solution storage tank 1 3 and the dilute solution storage tank 1 2 are connected to the inlets of the concentrated solution chamber and the dilute solution chamber of the RED subsystem, respectively. A concentrated solution pump 1 6 and a dilute solution pump 1 5 are arranged on the pipelines, respectively. The outlets of the RED subsystem are combined into one pipeline and connected to the inlet of the waste liquid recovery storage tank 1 4. Under the drive of an electrode liquid circulating pump 2 5, the electrode liquid circulates between a positive electrode 1 9 and a negative electrode 2 0. The absorbing liquid pump 1 3, the absorbing liquid pump 2 5, the refrigerant pump 7, the air extraction device 1 0, the main machine control system 1 1, the dilute solution pump 1 5, the concentrated solution pump 1 6, the waste liquid pump 1 7, and the electrode liquid circulating pump 2 5 are connected in parallel to an electricity storage device 1 8 through wires. Further, heat exchange pipe clusters are arranged in the generator 1, the condenser 2, the absorber 6, and the evaporator 8. Figure 1 and Figure 2The generator 1 and the condenser 2 need to be specially designed. The internal space of the generator 1 is divided into left and right chambers which do not affect each other, and heat exchange tube clusters are arranged in the two chambers. The low-grade heat source from outside flows in the heat exchange tube clusters, and the low-grade heat source from outside is divided into two branches and enters the left and right chambers respectively. After being output from the generator, the two branches are combined into one branch and output to the outside. The condenser 2 is also designed as two chambers which do not communicate with each other. The cooling water in the left chamber comes from the absorber 6, and the cooling water in the right chamber comes directly from the cooling tower. The cooling water flows into the heat exchange tube cluster inlet of the absorber 6 from the heat exchange tube cluster outlet of the left chamber of the condenser 2. The condenser 2 is a water-cooled condenser. The chilled water flows out after releasing heat to the refrigerant water through the heat exchange tube cluster of the evaporator 8. The solution heat exchanger 4 and the solution heat exchanger 28 are both plate heat exchangers. The throttling device can be a U-shaped tube, a manual expansion valve, a float ball expansion valve, a thermal expansion valve, an electronic expansion valve, a capillary tube, a orifice plate, etc.

[0011] Further, the host control system 11 controls the refrigeration capacity, working solution level and flow rate of the refrigeration machine, and the air extraction device 10 can be a mechanical vacuum pump air extraction device and an automatic air extraction device. The air extraction device extracts air in the system before the system runs, so that the system is in a vacuum state. In the system running process, the non-condensable gas in the system is discharged in time.

[0012] The application proposes a de-electricity absorption refrigeration method coupled with the principle of reverse electrodialysis, which is realized based on the above device, and the operation process is as follows:

[0013] First, the low-grade heat energy from outside is converted into the concentration difference energy of the working solution through the heat subsystem.

[0014] The left chamber of the generator 1 of the heat subsystem is used to drive the operation of the ARS system, and the right chamber is used to drive the operation of the RED subsystem. The low-grade heat source from outside is divided into two branches, which respectively enter the left and right chambers of the generator 1.

[0015] The left chamber of the generator 1 is pre-filled with dilute solution, and the right chamber is pre-filled with intermediate concentration solution. The concentration of the solution in the left chamber of the generator 1 is different from that in the right chamber. In the RED circuit, the concentrated and dilute solutions flowing into the respective chambers are mixed into one stream after flowing out of the RED subsystem, and then become intermediate concentration solution again, which enters the waste liquid recovery tank 14. The low-grade heat source from outside is input into the right chamber of the generator 1 to heat the intermediate concentration solution, and part of the low-boiling-point components in the solution, i.e. solvent, evaporates from the upper steam outlet of the right chamber of the generator 1. Since the boiling point of the solute in the intermediate concentration solution is much higher than that of the solvent, the steam that escapes from the generator contains almost no solute component, but only solvent vapor. Then the solvent vapor enters the right chamber of the condenser 2, is cooled by the cooling water flowing into the right chamber of the condenser 2, and is condensed into liquid dilute solution, which flows into the dilute solution tank 12. The evaporation of part of the solvent increases the concentration of the intermediate concentration solution in the right chamber of the generator 1, and the solution becomes concentrated solution, which flows out of the lower interface of the right chamber of the generator 1, enters the solution heat exchanger 2, and exchanges heat with the intermediate concentration solution that is mixed from the concentrated and dilute solutions flowing out of the RED subsystem. The concentrated solution releases heat and is cooled, and then enters the concentrated solution tank 13. Since the dilute solution in the dilute solution tank 12 is pure solvent at this time, the low conductivity of the solution is not conducive to the operation of the RED subsystem. The solution switching valve 23 arranged between the concentrated solution tank 13 and the dilute solution tank 12 can adjust the concentration of the dilute solution in the dilute solution tank 12. The outlet of the waste liquid recovery tank 14 is connected to the inlet of the right chamber of the generator 1, and the intermediate concentration solution in the waste liquid recovery tank 14 is driven by the waste liquid pump 17 to pass through the throttling device 2 to reduce the pressure, and then the low-pressure intermediate concentration solution enters the solution heat exchanger 2 to be heated, and then enters the right chamber of the generator 1, where it is regenerated into concentrated and dilute solutions under the driving of the low-grade heat source from outside, and the above-mentioned cycle is repeated. The outlets of the concentrated solution tank 13 and the dilute solution tank 12 are respectively connected to the inlets of the concentrated solution chamber and the dilute solution chamber of the RED subsystem, and the concentrated and dilute solutions are respectively pumped into the respective chambers of the RED subsystem by the concentrated solution pump 16 and the dilute solution pump 15.

[0016] Further, the low-grade heat source can be steam, hot water, high-temperature flue gas generated by burning fuel (light oil, heavy oil, gas, etc.), industrial waste heat, and solar energy, geothermal energy, etc. in nature.

[0017] Secondly, the chemical potential energy of the working solution is converted into electrical energy by the RED subsystem.

[0018] In the RED subsystem, the dilute and concentrated solution flow channels are arranged alternately between the cation and anion exchange membranes. The dilute and concentrated solutions are introduced into the dilute and concentrated solution chambers from the dilute solution tank 12 and the concentrated solution tank 13, and under the action of the solution concentration difference (chemical potential difference), the anions and cations of the solute permeate through the anion exchange membrane 22 and the cation exchange membrane 21, respectively, into the dilute solution chamber, forming a directional ion flow in the battery. The concentrated solution loses part of the anions and cations and becomes dilute, flowing out of the concentrated solution flow channel. The dilute solution obtains part of the anions and cations lost by the concentrated solution, and its concentration becomes higher, flowing out of the dilute solution flow channel and into the waste liquid recovery tank 14 together with the concentrated solution flowing out of the concentrated solution flow channel, becoming an intermediate concentration solution. The electrode liquid circulates between the anode and cathode chambers under the drive of the electrode liquid circulating pump 25. The metal ions in the electrode liquid are oxidized at the anode 19 to lose electrons and are reduced at the cathode 20 to gain electrons. The electrons flow from the anode 19 to the cathode 20 through the external circuit to generate an external current. Thus, the chemical potential energy of the working solution is converted into electrical energy.

[0019] Further, the electrical energy generated by the RED subsystem is stored in the electricity storage device 18. Since the absorption refrigeration system is affected by seasonal changes in actual application, its continuous use of low-grade heat energy is limited. Therefore, the electricity storage device 18 is added to the RED subsystem. When the absorption refrigeration machine is stopped, the RED subsystem can continue to work, and the electricity storage device 18 can store the direct current generated by the RED subsystem, so that the RED subsystem can fully and continuously use low-grade heat energy. In addition, the concentrated and dilute solutions separated by the generator can also be stored in the concentrated solution tank 13 and the dilute solution tank 12 in the form of concentration difference energy to meet the small-scale power generation requirements in some special situations (such as unit start and stop).

[0020] Further, the anion exchange membrane 22 and the cation exchange membrane 21 only allow the anions and cations in the concentrated solution to pass through, respectively. The side of the anode and cathode chambers is the cation exchange membrane 21 to prevent the anions in the electrode liquid from entering the solution flow channel. The anion exchange membrane 22 and the cation exchange membrane 21 are arranged alternately, that is, the cation exchange membrane 21 in the RED system is one more than the anion exchange membrane 22.

[0021] Further, the electrode includes a graphite electrode, a common metal (such as Cu, Zn, etc.), a noble metal electrode (such as Pt, Pd, etc.), and an alloy electrode thereof, such as a titanium-plated ruthenium-iridium alloy. The electrode liquid is FeCl2 / FeCl3, [Fe(CN)6] 4– / Fe(CN)6] 3– , or an alkali metal aqueous solution, etc. In the implementation case, [Fe(CN)6] 4– / Fe(CN)6]3– The salt solution of the redox couple is used with the titanium electrode plated with ruthenium iridium to achieve better power generation effect. The number of the stacks in the RED stack series system depends on the number of the stacks that can be driven by the concentration difference energy under specific conditions. The power generation power of each stack is the net power, which has subtracted the pump power consumption from the power generation power of the stack.

[0022] In the third step, the ARS subsystem converts the low-grade heat energy into cold energy under the driving of the power generated by the RED subsystem.

[0023] In the ARS loop, similar to the above-mentioned heat subsystem circulation mode, the external low-grade heat source input into the left chamber of the generator 1 heats the dilute solution in the left chamber to evaporate part of the solvent (refrigerant) to enter the condenser 2 from the upper interface of the left chamber of the generator. The dilute solution that loses part of the solvent is concentrated into a concentrated solution and flows out from the lower interface of the left chamber. The concentrated solution pump 5 pumps the concentrated solution into the solution heat exchanger 1 4 to reduce the temperature. The low-temperature concentrated solution is throttled and depressurized by the throttling device 3 7 to enter the absorber 6. The concentrated solution releases heat to the dilute solution from the absorber 6 in the solution heat exchanger 1 4 and then enters the absorber 6 to absorb the refrigerant vapor from the evaporator 8. The concentrated solution is diluted into a dilute solution and flows out from the bottom interface of the absorber 6. The dilute solution pump 1 3 pumps the dilute solution into the solution heat exchanger 1 4. The dilute solution absorbs the heat of the concentrated solution from the generator 1 and then flows back to the left chamber of the generator 1. The dilute solution is regenerated into a concentrated solution and refrigerant vapor by the external heat source in the left chamber of the generator 1 to complete the solution circulation.

[0024] The vapor generated from the top of the left chamber of the generator 1, i.e. the refrigerant in the ARS circulation, escapes from the top to enter the condenser 2. The refrigerant is cooled and condensed into liquid refrigerant by the cooling water flowing through the condenser 2. The refrigerant flows out from the lower end interface of the condenser 2, is throttled and depressurized by the throttling device 1 9, and is converted into low-temperature and low-pressure liquid refrigerant and a small part of flash vapor. The low-temperature and low-pressure liquid refrigerant enters the evaporator 8. The refrigerant pump 7 pumps the refrigerant in the evaporator 8 into the spraying device inside the evaporator 8. The sprayed refrigerant absorbs the heat of the chilled water in the evaporator 8 to become refrigerant vapor, enters the absorber 6, and is absorbed by the concentrated solution. The concentrated solution becomes a dilute solution to complete the refrigeration cycle.

[0025] Thus, the method of continuously converting low-grade heat energy into electric energy and cold energy based on the solution heat separation technology and the power generation principle of reverse electrodialysis is realized.

[0026] Further, the absorption liquid pump 3, the absorption liquid pump 5, the refrigerant pump 7, the air extraction device 10, the main control system 11, the dilute solution pump 15, the concentrated solution pump 16, the waste liquid pump 17 and the electrode liquid circulation pump 25 in the circulation system are all driven to operate by the electric energy generated by the RED. The electric energy generated by the RED subsystem is direct current (DC) stored in the electric energy storage device 18. For an alternating current motor, the direct current needs to be converted into alternating current (AC) by the inverter 29 before being delivered to the above-mentioned electric equipment. For a direct current motor, the inverter 29 is not required, and the electric energy storage device 18 directly delivers the direct current generated by the RED subsystem to each electric equipment.

[0027] Further, the dilute solution pre-placed in the left ventricle of the generator in the ARS is a working pair composed of a refrigerant and an absorbent. The refrigerant includes water, ammonia, amines, alcohols and freon, etc. The absorbent includes inorganic salts such as lithium bromide, organic salts such as sodium thiocyanate, lipids, and organic solvents such as ethers. Among them, the water-based working pair (including binary working pairs: H2O-LiBr, H2O-LiCl, H2O-LiI, H2O-NaOH, H2O-CaCl2, H2O-LiSCN, H2O-CsF, H2O-RbF, H2O-CsBr. Three ternary: LiBr aqueous solution + LiCl, CaCl2, LiSCN, NaSCN, CaCl2, ZnCl2, ZnBr2, C3H8O2, C2H6O2 one of them; LiCl aqueous solution + CaCl2. Four ternary: H2O-LiCl-CaCl2-ZnCl2, H2O-LiCl-CaCl2-MgCl2. Five ternary: H2O-LiBr-LiI-LiCl-LiNO3) mainly uses water as the refrigerant and salt as the absorbent. The ammonia-based working pair (including NH3-H2O, NH3-LiSCN, NH3-NaSCN, NH3-LiNO3, NH3-LiSCN-H2O, NH3-NaSCN-H2O, NH3-LiBr-H2O) uses ammonia as the refrigerant and water or salt as the absorbent. Since the boiling points of ammonia and water are not much different, the NH3-H2O absorption cycle needs to increase the rectification device. The alcohol-based working pair can be composed of methanol (CH3OH) + lithium or zinc salt of chlorobromine iodine or TFE (trifluoroethanol) or HFIP (hexafluoroisopropyl alcohol) and high-boiling organic solvents DMA, DMEU, DMPU, NMC, NMP, MEDEG, DMETEG (E181), PYR (pyrrolidone). The freon-based working pair is composed of R22, R134a, R32, R152a or non-azeotropic working pair and organic solvents (such as DMA, DMF, DEGDMF or E181).

[0028] The working solution in the specific embodiments of the patent takes lithium bromide aqueous solution (LiBr-H2O) as an example, water as the solvent, and the mass fraction of the lithium bromide aqueous solution should not exceed 65%. In both running and shutdown states, the lithium bromide aqueous solution should be in a liquid state to prevent crystallization of the solution.

[0029] The absorption refrigeration cycle to which the present application is applied is not only limited to single-effect cycle, but also applicable to double-effect cycle, triple-effect cycle and multi-effect cycle (the number of effects is equal to the number of generators, for example, compared with single-effect, one high-pressure generator and one high-temperature solution heat exchanger are added, and the high-temperature heat source is utilized twice in the high-pressure generator and the low-pressure generator), and in the four specific embodiments of the patent, single-effect cycle is taken as an example for description.

[0030] Further, as shown in the Figure 1 As shown in the

[0031] Further, as shown in the Figure 2 As shown in the

[0032] Further, as shown in the Figure 3 As shown in the

[0033] The present application has the following beneficial effects:

[0034] (1) Low-grade heat energy can be fully, efficiently and continuously utilized;

[0035] (2) The absorption refrigeration machine is completely independent of the power grid and can run independently;

[0036] (3) The adaptability to changes in external conditions is strong, and the quality requirement for low-grade heat energy is low;

[0037] (4) The power generation system is simple and reliable, and does not need precise and complex impeller power generation mechanical equipment;

[0038] (5) There are few moving parts, low noise, and management and maintenance are convenient;

[0039] (6) The system runs in a low-pressure state, has no explosion danger, and is safe and reliable;

[0040] (7) The generated electric energy is direct current, and has a certain energy storage effect. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 It is a coupling reverse electrodialysis principle of the de-electricity type absorption refrigeration cycle schematic diagram (without inverter).

[0042] Figure 2 It is a coupling reverse electrodialysis principle of the de-electricity type absorption refrigeration cycle schematic diagram (with inverter).

[0043] Figure 3 It is a coupling reverse electrodialysis principle of the de-electricity type absorption refrigeration cycle schematic diagram (increase the intermediate concentration solution and solvent heat exchange process).

[0044] In the figure: 1 generator; 2 condenser; 3 absorption liquid pump one; 4 solution heat exchanger one; 5 absorption liquid pump two; 6 absorber; 7 refrigerant pump; 8 evaporator; 9 throttling device one; 10 air extraction device; 11 main engine control system; 12 dilute solution storage tank; 13 concentrated solution storage tank; 14 waste liquid recovery storage tank; 15 dilute solution pump; 16 concentrated solution pump; 17 waste liquid pump; 18 electricity storage device; 19 anode; 20 cathode; 21 cation exchange membrane; 22 anion exchange membrane; 23 solution switching valve; 24 end plate; 25 electrode liquid circulating pump; 26 throttling device two; 27 throttling device three; 28 solution heat exchanger two; 29 inverter; 30 solution heat exchanger three.

[0045] In the figure, the direction of the arrow is the flow direction of the flow, the dotted line is the heat source flow, the thin dotted line is the cooling water flow, the thick dotted line is the ARS concentrated solution flow, the thick dotted line is the refrigerant flow, the thick solid line is the RED concentrated solution flow, the thin solid line is the RED dilute solution flow, the thin dotted line is the RED intermediate concentration solution flow and the dilute solution flow out of the ARS absorber, the thick dotted line of the RED electric pile is the electrode liquid flow. The thin double dotted line is the lead. DETAILED DESCRIPTION

[0046] The specific implementation process of the present application will be described in detail below in combination with the technical scheme and the drawings.

[0047] Example 1: Figure 1 It is a coupling reverse electrodialysis principle of the de-electricity type absorption refrigeration method working flow chart (without inverter). Taking a single-effect steam engine with refrigerating capacity of 1500kW and power distribution capacity of 6.64kW as an example, its rated parameters are: heat source rated steam pressure 0.1MPa, its condensate temperature 95℃; refrigerated water rated outlet / inlet temperature 7 / 14℃; cooling water rated outlet / inlet temperature 37 / 30℃. The specific implementation process includes the following steps:

[0048] The low-grade heat source (low-pressure steam) enters the generator 1 from the left side of the driving heat source inlet, and is divided into two paths, which enter the left chamber and the right chamber of the generator 1 respectively to release heat, and is condensed into condensed water which leaves the left and right chambers of the generator 1 and is combined into one path to leave the generator 1 from the left side of the driving heat source outlet.

[0049] The middle-concentration solution in the left and right chambers of the generator 1 is heated by the driving heat source, and part of the solvent water evaporates, and the water vapor generated in the left and right chambers enters the left and right chambers of the condenser 2 respectively. The condenser 2 is a water-cooled condenser, and the cooling water first enters the absorber 6 to absorb heat, and then flows out of the absorber 6 to enter the condenser 2 to absorb the phase change heat of the solvent vapor. The mixed vapor is condensed and cooled to 42°C by the cooling water. The solvent water in the right chamber of the condenser 2 flows out of the outlet of the condenser 2 and enters the dilute solution tank 12. The middle-concentration solution in the generator 1 is regenerated into a concentrated solution (the mass fraction of the concentrated solution is 61.14%) due to the evaporation of part of the solvent. The concentrated solution flows out of the bottom outlet of the left and right chambers respectively, and the concentrated solution flowing out of the left chamber is pumped into the solution heat exchanger 1 by the driving of the 5 absorption liquid pump. In the solution heat exchanger 1, the concentrated solution releases heat which is absorbed by the dilute solution, and the concentrated solution is cooled to 52.46°C and enters the absorber 6.

[0050] The concentrated solution flowing out of the right chamber of the generator 1 enters the solution heat exchanger 2 28 to exchange heat with the middle-concentration solution, and the concentrated solution is cooled after releasing heat and enters the concentrated solution tank 13. The solvent vapor generated from the generator is pure water vapor, which flows into the solvent of the dilute solution tank 12 after being condensed in the condenser 2, and is a low-concentration dilute solution. Since the concentration of this dilute solution is lower than the required concentration (0.002 kg / kg), the solution switching valve 23 between the concentrated solution tank 13 and the dilute solution tank 12 is opened, and part of the concentrated solution in the concentrated solution tank 13 is pumped into the dilute solution tank 12 by the driving of the concentrated solution pump 16, so that the concentration of the dilute solution in the dilute solution tank 12 reaches the required concentration.

[0051] In the second step, the dilute solution (LiBr aqueous solution, concentration 0.002 kg / kg) and the concentrated solution (LiBr aqueous solution, concentration 0.6114 kg / kg) in the dilute solution tank 12 and the concentrated solution tank 13 enter the dilute solution chamber and the concentrated solution chamber respectively under the driving of the dilute solution pump 15 and the concentrated solution pump 16. Under the action of the difference in solution concentration (chemical potential difference), the anions (in this specific embodiment, Br - ) and cations (in this specific embodiment, Li +) respectively through the anion exchange membrane 22 and the cation exchange membrane 21, into the left and right adjacent dilute solution chambers in opposite directions, so the flowing directions of the anions and the cations are opposite when entering the dilute solution chambers respectively, directional ion flow is formed in the battery, and potential difference is formed on both sides of the battery. The concentration of the concentrated solution in the concentrated solution chamber is reduced to become the dilute solution after losing part of the anions and the cations, and the dilute solution flows out through the dilute solution flow channel. The concentration of the dilute solution is increased after obtaining part of the anions and the cations lost by the concentrated solution, and the dilute solution flows out through the dilute solution flow channel. The outflowing dilute solution and the outflowing concentrated solution from the concentrated solution flow channel are mixed and then flow into the waste liquid recovery tank 14 to become the intermediate concentration solution (LiBr aqueous solution, concentration is 0.4076 kg / kg). The electrode liquid is circulated between the cathode electrode chamber and the anode electrode chamber under the driving of the electrode liquid circulating pump 25, the metal ions are oxidized to lose electrons at the anode electrode 19, and the metal ions obtain electrons to be reduced at the cathode electrode 20. The electrons flow from the anode electrode 19 to the cathode electrode 20 through the external circuit to generate the external current. The chemical potential energy of the final solution is converted into electric energy by the RED subsystem, and the power generation capacity of the system is 6.64 kW.

[0052] The electric energy generated by the RED subsystem is direct current, and the direct current can be directly stored. Therefore, the power storage device 18 is arranged in the RED subsystem, the RED subsystem can continue to work when the absorption refrigerator stops, and the power storage device 18 can store the direct current generated by the RED subsystem. Therefore, the RED system can not only avoid being affected by the seasonal work of the ARS system, make the low-grade heat energy more continuously and effectively utilized, and improve the energy utilization rate, but also can supply the excess electric energy generated by the RED system to other electric equipment except the ARS to reduce the energy consumption.

[0053] The electric energy consumed by the electric equipment in the embodiment 1 includes direct current, and the direct current generated by the RED system can be directly supplied to the above-mentioned electric equipment.

[0054] In the third step, the ARS subsystem converts the low-grade heat energy into cold energy under the driving of the electric energy generated by the RED subsystem to realize refrigeration. The solvent water (i.e. the refrigerant water) of the condenser 2 is throttled and depressurized to 0.79 kPa through the throttling device, enters the evaporator 8 at 4℃, and the throttled and depressurized refrigerant is a gas-liquid mixture. The gas in the gas-liquid mixture escapes from the upper interface of the evaporator 8 into the absorber 6, and the refrigerant water in the gas-liquid mixture falls into the lower part of the evaporator 8 and flows out from the lower outlet of the evaporator 8. The refrigerant water enters the spraying device in the evaporator 8 under the driving of the refrigerant pump 7, sprays the refrigerant water to the heat exchange coil in the evaporator 8, and the refrigerant water is phase changed after absorbing the heat of the chilled water in the absorption tube. The gaseous refrigerant vapor enters the absorber 6 from the upper outlet of the evaporator 8. The chilled water at 14℃ releases heat and is cooled in the evaporator 8, and then flows out at 7℃ to achieve the refrigeration purpose.

[0055] The refrigerant vapor from the evaporator 8 enters the absorber 6, and the concentrated solution from the left chamber of the generator 1 enters the spraying device at the top of the absorber 6 under the drive of the solution pump 5, and the concentrated solution absorbs the refrigerant vapor to become a dilute solution in the process of downward spraying, and falls into the lower part of the absorber 6 and enters the solution heat exchanger 4 under the drive of the solution pump 3. A large amount of heat of dissolution is released in the process of absorbing the refrigerant vapor, so that cooling water needs to be introduced into the absorber 6, and the cooling water exchanges heat with the solution in the absorber 6 through the heat exchange tube cluster, and the heat absorbed includes the heat of dissolution released in the process of absorbing the refrigerant, the phase change heat released when the refrigerant changes from gas to liquid, and the heat released in the process of supercooling of the dilute solution, so that the absorption process can be stably carried out.

[0056] The air extraction device 10 is arranged in the ARS subsystem to maintain the internal system in a vacuum state at all times.

[0057] The heat load of the low-grade heat source driving the RED subsystem of the generator 1 is 930 kW, and the heat load of the driving heat source of the ARS subsystem is 2027 kW. The flow rate of the cooling water introduced into the absorber 6 is 129.64 kg / s, and the additional cooling water required for the condenser 2 to condense the solvent vapor is 71.86 kg / s. The flow rate of the concentrated solution required to be introduced into the RED subsystem is 1.23 kg / s, the flow rate of the dilute solution is 0.3564 kg / s, and the flow rate of the solution is 0.022 m / s.

[0058] At this point, the method of coupling the reverse electrodialysis principle to generate power with the concentrated solution generated by the generator as the working solution is realized, and the waste heat absorption type refrigeration machine is "depowered" to refrigerate (without an inverter).

[0059] Embodiment 2: Also a depowered absorption type refrigeration method coupling the reverse electrodialysis principle, Figure 2 The working principle of the system with an inverter is shown. Compared with the specific embodiment 1, a DC-AC conversion device is added at the end of the RED power generation system in the specific embodiment 2, and the direct current generated by the power stack is converted into alternating current before being supplied to the power consumption devices in the lithium bromide absorption type refrigeration system, such as the solution pump, the vacuum pump, and the solution pump of the RED power stack itself. This is because the electric energy generated by the RED subsystem is direct current, which is different from the alternating current commonly used in production and life, and may not meet the power supply requirements of general-purpose pumps and other devices in large-scale production on the market. Therefore, it is necessary to consider the case of converting direct current into alternating current in actual production, and therefore an inverter 29 is arranged after the power storage device 18 in the RED subsystem to realize DC-AC conversion. In general electrical engineering calculations, the conversion efficiency of direct current to alternating current is not close to 100%, so the power generation capacity of the RED subsystem in the embodiment 2 is larger than that required in the above-mentioned embodiment 1, so as to make up for the energy loss in the DC-AC conversion of the inverter.

[0060] In addition, the working solution flow of the specific implementation case 2 is completely the same as that in the implementation case 1, and the difference is that the flow in the implementation case 2 is slightly larger than that in the implementation case 1, and a larger power generation capacity is generated to offset the energy loss in the inverter.

[0061] In the first step, the solution flow is completely the same as that in the embodiment 1, which will not be described here. In the energy conversion path of the power generation and power supply circuit, the evaporation separation function is used to convert the heat energy into the concentration difference energy, the RED system is used to convert the concentration difference energy into the electric energy and store in the power storage device, then the AC-DC converter is used to convert the direct current into the alternating current, and finally the electric appliance is supplied. The difference is that, due to the energy loss of the AC-DC converter, the RED subsystem needs to have a higher power generation capacity, so the RED subsystem needs to input a larger flow of working solution to obtain more concentration difference energy to meet the power generation requirement. After the power generation capacity calculation of the RED subsystem, the solution flow into the left chamber of the generator 1 remains unchanged (ARS circuit), and the solution flow into the right chamber thereof becomes 1.18 times of the original (RED circuit), so as to ensure that more concentrated and dilute solutions are separated for use of the RED subsystem. Due to the increase of the solution separation amount, the demand for the driving heat source and the demand for the cooling water are also increased.

[0062] In the second step, as known from the foregoing, the power generation capacity requirement of the RED subsystem is larger than that in the implementation case 1. In order to more conveniently realize such a change, the geometric size of the RED stack is temporarily not changed, and only the solution membrane flow rate is adjusted from 0.022 m / s to 0.026 m / s. Because the solution flow is increased, the concentration difference energy carried by the solution is also increased. Even in the case of single-stack concentration difference energy power generation, the power generation efficiency will have a large range of fluctuations, but in the system, the multi-stack gradient utilization of the concentration difference energy can make the concentration difference energy be fully utilized, and the change with the flow rate is very small. Therefore, when the flow rate is increased, the stack can obtain the required power generation capacity under the condition that the size and other operating conditions are unchanged. Finally, the power generation capacity of the RED subsystem is 7.37 kW, which meets the energy requirements of various electric appliances in the system.

[0063] In the third step, the ARS system is driven by the low-grade heat energy and the electric energy generated by the RED subsystem to produce cold energy, and the rated parameters of the absorption refrigeration system are the same as those in the embodiment 1. The difference is that the solution flow rate in the RED subsystem is 0.026 m / s, so the solution separation amount in the right chamber of the generator is 18% more than that in the implementation case 1, and the water vapor amount required to be cooled by the condenser is also increased accordingly.

[0064] The heat load of the low-grade heat source driving the RED subsystem is 1097.4 kW, and the heat load of the driving heat source of the ARS subsystem is 2027 kW. The flow rate of the cooling water flowing into the absorber 6 is 129.64 kg / s, and the additional cooling water required for condensing the solvent vapor in the condenser 2 is 84.80 kg / s. The flow rate of the concentrated solution required for the RED subsystem is 1.45 kg / s, and the flow rate of the dilute solution is 0.42 kg / s.

[0065] Thus, the method of coupling reverse electrodialysis with the generator to generate power with the concentrated solution as the working solution, and making the waste heat absorption refrigeration machine "de-electric" refrigeration is realized.

[0066] Embodiment 3: It is also a de-electric absorption refrigeration method (RED power generation and ARS non-synchronous operation) coupling the principle of reverse electrodialysis. The working principle is still shown in the flowchart Figure 1 Unlike the specific embodiment 1, the real-time power generation of the RED and the power distribution of the ARS are not completely synchronized in the specific embodiment 3. The ARS is not started all the time in actual application, so the two solutions separated when the ARS subsystem is started can be stored in the concentrated and dilute solution storage tanks. The RED subsystem gradually converts the concentration difference energy into electrical energy at a slower speed (relative to the ARS subsystem) in a longer time, and stores it in the power storage device for use when the ARS subsystem is started. The advantage of arranging the system in this way is that the flow rate of the concentrated and dilute solutions in the RED subsystem is reduced, which reduces the pump power loss of the subsystem itself, and on the other hand, the residence time of the concentrated and dilute solutions in the RED stack is relatively extended, the ion transmembrane migration time is extended, and the overall economic efficiency is improved.

[0067] In the first step, the solution flow is exactly the same as in embodiment 1, which will not be described here. Since it is assumed that the ARS subsystem is not running all the time, the left chamber of the generator 1 is not continuous, and only works in the time period when there is a need for refrigeration. The right chamber of the generator 1 has two working modes. The first is to start and stop synchronously with the left chamber, which requires that the right chamber of the generator 1 and the right chamber of the condenser 2 complete a large amount of solution separation in the ARS running time to meet the solution demand of the RED subsystem in a longer running time. The second working mode is that the solution separation rate of the right chamber of the generator 1 matches the solution rate input into the RED subsystem. At this time, as long as the RED subsystem works, the right chamber of the generator 1 and the right chamber of the condenser 2 need to be in a running state. Since the RED subsystem converts the concentration difference energy into electrical energy at a slower speed, the required concentrated and dilute solution flow is reduced, so the right chamber of the generator 1 separates the solution at a smaller rate. In the calculation of this case, in order to make the ARS subsystem generator 1 left and right chamber solution separation work synchronous and start and stop as a whole, the first working mode is used.

[0068] The second step, the solution flow in the RED subsystem and the power generation principle and implementation case 1 are the same, here do not make superfluous. Different from it, because the solution is gradually used in a long time, the solution membrane flow rate will be more obvious reduction. With a day in the ARS unit operation 12 hours, RED subsystem if running 24 hours for calculation, the solution membrane flow rate can be reduced to 50% of the implementation case 1, namely the solution flow rate in the RED subsystem is 0.011 m / s. At this time, the pump power consumption of RED subsystem itself is significantly reduced. After calculation, compared with the implementation case 1, the RED pump power consumption is reduced by nearly 83%. And in the required number of stacks, case 1 needs 13 stacks to complete the full use of concentration difference energy, and this case only needs 7 stacks to complete, saving 46% of ion exchange membrane investment.

[0069] The generator 1 is used to drive the RED subsystem input low-grade heat source heat load is 930 kW, the driving heat source heat load of ARS subsystem is 2027kW. From the absorber 6 into the cooling water flow is 129.64 kg / s, cooling condenser 2 to supplement the cooling water quantity for cooling condensed solvent vapor is 71.86kg / s. The RED subsystem required into the concentrated solution flow is 0.615kg / s, the dilute solution flow is 0.1782kg / s.

[0070] So far, the non-synchronous operation of RED power generation and ARS refrigeration is realized, and the coupling reverse electrodialysis principle makes the waste heat absorption refrigeration machine "off electricity" refrigeration method.

[0071] Example 4: Figure 3 It is a kind of off electricity type absorption refrigeration method of coupling reverse electrodialysis principle work flow chart (increase intermediate concentration solution and solvent heat exchange process).

[0072] The first step, in the RED loop, the middle concentration solution in the right chamber of the generator 1 is heated by the driving heat source, part of the solvent water in the solution evaporates, the water vapor generated escapes from the upper outlet of the right chamber into the right chamber of the condenser 2. The cooling water is introduced into the right chamber of the condenser 2 to absorb the phase change heat of the solvent vapor, and the vapor is condensed into liquid solvent water. The solvent water in the right chamber flows out from the lower outlet of the condenser 2 and enters the solution heat exchanger three 30, which is cooled again by the middle concentration solution flowing through the solution heat exchanger three 30, and then flows into the dilute solution tank 12. The solution heat exchanger three 30 can be added to the system to further heat exchange between the dilute solution and the middle concentration solution, so that the middle concentration solution can obtain more heat, reduce the heat load of the heat source of the generator, and improve the overall efficiency of the system. The concentrated solution flowing out of the right chamber of the generator 1 enters the solution heat exchanger two 26 and exchanges heat with the dilute solution. The concentrated solution releases heat and cools down, then enters the concentrated solution tank 13. The solvent vapor generated from the generator is pure water vapor, which flows into the dilute solution tank 12 after being condensed in the condenser 2. Part of the concentrated solution in the concentrated solution tank 13 is introduced into the dilute solution tank 12 under the drive of the concentrated solution pump 16, so that the concentration of the dilute solution in the dilute solution tank 12 reaches the required concentration (0.002 kg / kg). The middle concentration solution flowing out of the waste liquid recovery tank 14 is driven by the waste liquid pump 17 to enter the solution heat exchanger three 30 and exchange heat with the dilute solution flowing out of the right chamber of the condenser 2, and then enter the solution heat exchanger two 28 and exchange heat with the concentrated solution flowing out of the right chamber of the generator 1.

[0073] The second step, the chemical potential energy of the solution is converted into electrical energy by the RED subsystem, and the power generation of the system is 6.64 kW.

[0074] The third step, the ARS converts low-grade heat into cold under the drive of the electrical energy generated by the RED subsystem, realizing refrigeration.

[0075] The heat load of the low-grade heat source driving the RED subsystem is 900 kW, and the heat load of the driving heat source of the ARS subsystem is 2027 kW. The flow rates of the cooling water introduced into the absorber 6 and the right chamber of the condenser are 129.64 kg / s and 69.54 kg / s, respectively. The flow rates of the concentrated solution and the dilute solution required by the RED subsystem are 1.23 kg / s and 0.3564 kg / s, respectively. The flow rate of the chilled water in the evaporator 8 is 51.23 kg / s.

[0076] Thus, the method of increasing the heat exchange process between the middle concentration solution and the dilute solution and coupling the principle of reverse electrodialysis to make the absorption refrigerating machine run "off electricity" is realized.

[0077] The above embodiments only express the implementation ways of the present application, and cannot be understood as the limitation to the scope of the present application patent. It should be pointed out that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application.

Claims

1. A de-electricity absorption refrigeration device coupled with the principle of reverse electrodialysis, characterized in that, The described electricity-eliminating absorption refrigeration device is a low-grade heat energy driven direct power generation powered absorption refrigeration system, which realizes "heat-electricity" conversion by low-grade heat energy driving to continuously provide power for the absorption refrigeration machine; the system comprises three subsystems: a heat subsystem, an inverse electrodialysis (RED) subsystem and an absorption refrigeration system (ARS) subsystem; The heat subsystem is composed of a generator (1), a condenser (2), a dilute solution storage tank (12), a concentrated solution storage tank (13), a waste liquid recovery storage tank (14), a dilute solution pump (15), a concentrated solution pump (16), a waste liquid pump (17), a solution switching valve (23), a throttling device two (26) and a solution heat exchanger two (28), and each device is connected through a pipeline; the ARS subsystem is composed of the generator (1), the condenser (2), an absorption liquid pump one (3), a solution heat exchanger one (4), an absorption liquid pump two (5), an absorber (6), a refrigerant pump (7), an evaporator (8), a throttling device one (9) and a throttling device three (27); the RED subsystem is mainly composed of a positive electrode (19), a negative electrode (20), interlaced cation exchange membranes (21), interlaced anion exchange membranes (22), end plates (24), an anode chamber and a cathode chamber separated by the end plates (24), the positive electrode (19), the negative electrode (20) and the cation exchange membranes (21) at both ends, and interlaced dilute and concentrated solution chambers separated by the interlaced anion exchange membranes (22) and the cation exchange membranes (21); electrode liquid between the negative and positive electrode chambers flows outside the RED stack under the driving of an electrode liquid circulating pump (25); The characteristics are that: The generator (1) in the heat subsystem is composed of left and right chambers that do not affect each other, the left chamber is used for driving the operation of the ARS system, and the right chamber is used for driving the operation of the RED subsystem, and the external low-grade heat source is divided into two branches and enters the left chamber and the right chamber through pipelines; the condenser (2) is also composed of left and right chambers that do not affect each other; The left chamber of the generator (1) is connected with the left chamber of the condenser (2), and the right chamber of the generator (1) is connected with the right chamber of the condenser (2); the left chamber of the condenser (2) is communicated with the evaporator (8) through a pipeline, and a throttling device (9) is arranged on the pipeline; the refrigerant pump (7) pumps the refrigerant in the evaporator (8) into the spraying device; the right chamber of the condenser (2) is communicated with the dilute solution storage tank (12); the liquid outlet of the right chamber of the generator (1) is communicated with the solution heat exchanger (28), and the solution heat exchanger (28) is communicated with the concentrated solution storage tank (13); the liquid inlet of the right chamber of the generator (1) is connected with the liquid outlet of the waste liquid recovery storage tank (14) through a pipeline, and a waste liquid pump (17), a throttling device (26) and a solution heat exchanger (28) are arranged on the pipeline; the left chamber of the generator (1) is communicated with the absorber (6), and the concentrated solution in the left chamber of the generator (1) is pumped into the solution heat exchanger (4) by the absorbing liquid pump (5); the solution heat exchanger (4) is communicated with the absorber (6), and a throttling device (27) is arranged on the pipeline; the concentrated solution is diluted by the absorber (6), and then the dilute solution is pumped into the solution heat exchanger (4) by the absorbing liquid pump (3); The gas extraction device (10) is connected with the absorber (6) and the liquid outlet of the absorber (6) through a pipeline; a solution switching valve (23) is arranged on the connecting pipeline between the concentrated solution storage tank (13) and the dilute solution storage tank (12), and the outlets of the concentrated solution storage tank (13) and the dilute solution storage tank (12) are connected with the liquid inlets of the concentrated solution chamber and the dilute solution chamber of the RED subsystem respectively, and the pipeline is respectively provided with a concentrated solution pump (16) and a dilute solution pump (15); The liquid outlet of the RED subsystem is connected with the liquid inlet of the waste liquid recovery storage tank (14) through a pipeline; under the driving of the electrode liquid circulating pump (25), the electrode liquid circulates between the anode (19) and the cathode (20).

2. A decoupled absorption refrigeration device coupled with the principle of reverse electrodialysis according to claim 1, characterized in that, The absorbing liquid pump (3), the absorbing liquid pump (5), the refrigerant pump (7), the gas extraction device (10), the main machine control system (11), the dilute solution pump (15), the concentrated solution pump (16), the waste liquid pump (17) and the electrode liquid circulating pump (25) are connected in parallel with the electricity storage device (18) through wires; heat exchange pipe clusters are arranged in the generator (1), the condenser (2), the absorber (6) and the evaporator (8); the condenser (2) is a water-cooled condenser; the solution heat exchangers (4) and (28) are both plate heat exchangers.

3. A de-electricity absorption refrigeration method coupled with the principle of reverse electrodialysis, characterized by, The method is driven by low-grade heat energy completely, and the low-grade heat energy is first converted into chemical potential energy of concentrated and dilute solutions by a generator according to any one of claims 1-2, and then the chemical potential energy is converted into electric energy by an inverse electrodialysis stack to provide electric energy for a load absorption refrigerator; the concentrated and dilute solutions losing part of the chemical potential energy flow out of the stack and become intermediate solutions to return to the generator to be regenerated into the concentrated and dilute solutions under the driving of the low-grade heat energy, thus completing a cycle of power generation; finally, the low-grade heat energy is converted into cold energy, including a refrigerant cycle and a solution cycle; working solutions in the generator are heated by the low-grade heat energy to release refrigerant vapor, the refrigerant vapor is cooled and condensed into liquid refrigerant by a condenser, enters an evaporator to be heated and evaporated after throttling, thus completing the refrigerant cycle and producing cold energy; the refrigerant vapor enters an absorber to be absorbed by concentrated solutions from the generator, the concentrated solutions become dilute solutions to return to the generator again, and are regenerated into concentrated solutions and refrigerant vapor under the heating of the low-grade heat source, thus completing the solution cycle.

4. A de-electricity absorption refrigeration method coupled with the principle of reverse electrodialysis according to claim 3, characterized in that, The operation process of the de-electric absorption refrigeration method is as follows: In the first step, low-grade heat energy from outside is converted into the concentration difference energy of working solutions by a heat subsystem; The left chamber of the generator (1) of the heat subsystem is used to drive the operation of the ARS system, and the right chamber is used to drive the operation of the RED subsystem. The external low-grade heat source is divided into two branches and enters the left chamber and the right chamber of the generator (1) respectively. The left chamber of the generator (1) of the ARS system is pre-placed with a dilute solution, and the right chamber is pre-placed with an intermediate concentration solution. The solution concentrations in the left chamber and the right chamber are different. In the RED circuit, the concentrated and dilute solutions flowing into each concentrated and dilute solution chamber flow out of the RED subsystem, are then combined into one, and become an intermediate concentration solution again. The intermediate concentration solution enters the waste liquid recovery tank (14). The external low-grade heat source is input into the right chamber of the generator (1) to heat the intermediate concentration solution. Part of the low-boiling components in the solution, i.e., the solvent, evaporates and escapes from the upper steam outlet of the right chamber of the generator (1). Then the solvent vapor enters the right chamber of the condenser (2), is cooled by the cooling water input into the right chamber of the condenser (2), and is condensed into a liquid dilute solution. The liquid dilute solution flows into the dilute solution storage tank (12). The evaporation of part of the solvent water increases the concentration of the intermediate concentration solution in the right chamber of the generator (1), and the intermediate concentration solution becomes a concentrated solution. The concentrated solution flows out from the lower interface of the right chamber of the generator (1), enters the second solution heat exchanger (28), and exchanges heat with the intermediate concentration solution formed by the combination of the concentrated and dilute solutions flowing out of the concentrated and dilute solution chambers of the RED subsystem. The concentrated solution releases heat and cools down, and then enters the concentrated solution storage tank (13). The solution switching valve (23) arranged between the concentrated solution storage tank (13) and the dilute solution storage tank (12) can adjust the concentration of the dilute solution in the dilute solution storage tank (12). The intermediate concentration solution in the waste liquid recovery tank (14) is driven by the waste liquid pump (17) to pass through the second throttling device (26) to reduce the pressure. The low-pressure intermediate concentration solution enters the second solution heat exchanger (28), is heated, and then enters the right chamber of the generator (1). Under the driving of the external low-grade heat source, the intermediate concentration solution is regenerated into a concentrated and dilute solution, and the above-mentioned cycle is repeated. The outlets of the concentrated solution storage tank (13) and the dilute solution storage tank (12) are respectively connected with the liquid inlets of the concentrated solution chamber and the dilute solution chamber of the RED subsystem. The concentrated and dilute solutions are respectively pumped into the concentrated and dilute solution chambers of the RED subsystem by the driving of the concentrated solution pump (16) and the dilute solution pump (15). In the second step, the chemical potential energy of the working solution is converted into electrical energy by the RED subsystem. In the RED subsystem, the interlaced concentrated and dilute solution flow channels are formed between the interlaced anion exchange membrane and cation exchange membrane. The dilute and concentrated solutions are introduced into the dilute and concentrated solution chambers from the dilute solution storage tank (12) and the concentrated solution storage tank (13) respectively. Under the action of the solution concentration difference, the anions and cations of the solute respectively pass through the anion exchange membrane (22) and the cation exchange membrane (21) and enter the dilute solution chamber. In the battery, a directional ion flow is formed. The concentrated solution loses part of the anions and cations, becomes dilute, and flows out of the concentrated solution flow channel. The dilute solution obtains part of the anions and cations lost by the concentrated solution, the concentration of the dilute solution becomes high, and the dilute solution flows out of the dilute solution flow channel. The concentrated solution flowing out of the concentrated solution flow channel and the dilute solution flow out of the dilute solution flow channel together flow into the waste liquid recovery tank (14) and become an intermediate concentration solution. The electrode solution circulates between the cathode and anode chambers under the drive of the electrode solution circulating pump (25), the metal ions in the electrode solution lose electrons at the anode (19) and gain electrons at the cathode (20) to be reduced, and the electrons flow from the anode (19) to the cathode (20) through an external circuit to generate an external current; thus, the chemical potential energy of the working solution is converted into electrical energy; In the third step, the ARS subsystem converts low-grade heat into cold energy under the drive of the electrical energy generated by the RED subsystem; In the ARS circuit, the low-grade heat source outside the left chamber of the generator (1) heats the dilute solution in the left chamber to make part of the solvent evaporate and flow into the condenser (2) from the upper interface of the left chamber; the dilute solution losing part of the solvent is concentrated into a concentrated solution and flows out from the lower interface of the left chamber, the concentrated solution is pumped into the solution heat exchanger I (4) by the absorption liquid pump II (5) to be cooled, the low-temperature concentrated solution is throttled and depressurized by the throttling device III (27) to enter the absorber (6), the concentrated solution releases heat to the dilute solution from the absorber (6) in the solution heat exchanger I (4) and then enters the absorber (6) to absorb the refrigerant vapor from the evaporator (8), the concentrated solution is diluted into a dilute solution and flows out from the bottom interface of the absorber (6), the dilute solution is pumped into the solution heat exchanger I (4) by the absorption liquid pump I (3), the dilute solution absorbs heat from the concentrated solution from the generator (1) and then flows back to the left chamber of the generator (1), and the dilute solution is regenerated into a concentrated solution and refrigerant vapor in the left chamber of the generator (1) after being heated by the external heat source, completing the solution circulation; The vapor generated from the top of the left chamber of the generator (1) escapes from the top to enter the condenser (2) and is condensed into liquid refrigerant by the cooling water flowing through the condenser (2), the liquid refrigerant flows out from the lower end interface of the condenser (2), is throttled and depressurized by the throttling device I (9), and is converted into low-temperature and low-pressure liquid refrigerant and a small amount of flash vapor, the low-temperature and low-pressure liquid refrigerant enters the evaporator (8), the refrigerant pump (7) pumps the refrigerant in the evaporator (8) into the spraying device inside the upper part of the evaporator (8), the sprayed refrigerant absorbs the heat of the chilled water in the evaporator (8) to become refrigerant vapor, enters the absorber (6) to be absorbed by the concentrated solution, and the concentrated solution becomes a dilute solution, completing the refrigeration cycle.

5. A decoupled absorption refrigeration process coupled with the principle of reverse electrodialysis according to claim 4, characterized in that, The absorption liquid pump I (3), the absorption liquid pump II (5), the refrigerant pump (7), the air extraction device (10), the main machine control system (11), the dilute solution pump (15), the concentrated solution pump (16), the waste liquid pump (17), and the electrode solution circulating pump (25) in the circulation system are driven to operate by the electrical energy generated by the RED subsystem; the electrical energy generated by the RED subsystem is stored in the electricity storage device (18).

6. A de-electricity absorption refrigeration method coupled with the principle of reverse electrodialysis according to claim 4, characterized in that, The dilute solution previously placed in the left chamber of the generator in the ARS is a working pair composed of a refrigerant and an absorbent, including a water-based working pair, an ammonia-based working pair, an alcohol-based working pair, and a freon-based working pair.

7. A decoupled absorption refrigeration process coupled with the principle of reverse electrodialysis according to claim 6, characterized in that, The water-based working medium pair mainly uses water as refrigerant and salt as absorbent; the ammonia-based working medium pair uses ammonia as refrigerant and water or salt as absorbent; the alcohol-based working medium pair can be composed of methanol and lithium or zinc salt of chloro-bromo-iodine or can be composed of trifluoroethanol or hexafluoroisopropyl alcohol and high-boiling organic solvent; the freon-based working medium pair is composed of R22, R134a, R32, R152a or non-azeotropic working medium and organic solvent.

8. A decoupled absorption refrigeration method incorporating the principle of reverse electrodialysis according to claim 4, characterized in that, The refrigeration method is suitable for absorption refrigeration cycle, which is not only limited to single-effect cycle but also suitable for double-effect cycle, triple-effect cycle and multi-effect cycle.

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