A hybrid working fluid reverse electrodialysis low-grade heat energy power generation system with two feed inlets

Abstract

The present invention relates to a hybrid working fluid reverse electrodialysis low-grade thermal energy power generation system with double feed inlets, which includes a heat generation module, a working condition adjustment module and a concentration difference power generation module. The heat generation module is used to convert low-grade thermal energy into chemical potential energy; the working condition adjustment module conducts processes of conductivity adjustment, temperature adjustment, pressure adjustment and flow rate adjustment on the dilute solution and the concentrated solution according to the working conditions; the concentration difference power generation module utilizes the salt concentration difference between the dilute solution and the concentrated solution to carry out the reverse electrodialysis power generation process. This system uses a liquid distribution pipeline to respectively lead the dilute and concentrated solutions to different feed inlets of the generator, reducing or eliminating the dissipation losses generated in the heat transfer process and the solution mixing process; adopts an alternative solvent with low boiling point and latent heat of vaporization to reduce the energy consumption and vacuum degree of the heat generation module; at the same time, a regulator is introduced to adjust the conductivity of the solution, reducing the internal resistance loss, and giving full play to the complementary advantages of the hybrid working fluid. The whole system has a simple structure, reliable operation and adjustable parameters.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy, and particularly to a hybrid working fluid reverse electrodialysis low-grade heat energy power generation system with a double feed inlet. Background Art

[0002] Energy is the cornerstone of social and economic development. With the rapid development of society, the demand for primary energy by humans has been increasing day by day. However, with the excessive exploitation and use of natural resources by humans, the reserves of primary energy are decreasing day by day, and the existing oil reserves are only enough for about 80 years. At the same time, due to the generation of a large amount of pollutants and carbon dioxide during the combustion process of primary energy, environmental problems have become increasingly prominent. According to statistics, if the existing energy use mode cannot be changed, the earth's temperature will rise by 6°C by the end of the 21st century. Therefore, it is urgent to improve the efficiency of existing energy utilization technologies and reduce the consumption of primary energy.

[0003] Waste heat is the heat dissipated into the environment in the form of heat energy during industrial production. Waste heat resources are very rich and widely distributed in industries such as petroleum, iron and steel, coal, and building materials, accounting for about one-third of the energy input in industrial production, and are regarded as the 5th large conventional energy source after coal, petroleum, natural gas, and hydropower. Since this part of the energy is not effectively utilized in the production process, a great loss of energy is caused. Therefore, the efficient utilization of waste heat can significantly improve the utilization efficiency of primary energy. Given that most industrial production uses electric energy as the main driving energy, and the transmission and matching of electric energy are relatively easy, it is more suitable for industrial actual situations to convert waste heat energy into electric energy.

[0004] Existing waste heat power generation technologies include: steam turbine power generation, organic Rankine cycle power generation, total flow turbine power generation, screw expander power generation, and reverse electrodialysis heat engine power generation. Except for the reverse electrodialysis heat engine power generation technology, other power generation technologies are only applicable to medium-high grade and high-grade waste heat, and problems such as efficiency, working fluid selection, turbine manufacturing, and economy have been plaguing the development and application of the above technologies, resulting in most technologies remaining at the experimental and theoretical levels. More notably, low-grade waste heat accounts for about 42% of the total waste heat, and the efficient utilization of low-grade waste heat can further increase the overall utilization efficiency of waste heat resources.

[0005] Reverse electrodialysis heat engine technology is an ideal low-grade waste heat power generation technology. This technology uses a generator to convert the heat energy in waste heat into the chemical potential energy between salt solutions, and uses reverse electrodialysis technology to convert the chemical potential energy into electrical energy, thereby realizing power generation using waste heat. Since there is no irreversible loss in the reverse electrodialysis power generation process under ideal conditions, its efficiency is relatively high. However, there are still many problems in the existing reverse electrodialysis heat engine system: First, the dilute solution and the concentrated solution that complete the power generation process are directly mixed, resulting in dissipative irreversible losses and reducing the system efficiency; Second, the working fluid usually uses water as a solvent. Due to the large latent heat of vaporization of water, the heat generation module consumes a high amount of energy; Third, the normal boiling point of water is high, and when using low-grade waste heat for power generation, the system has a high vacuum degree; Fourth, when using other liquids such as ethanol as a solvent, the conductivity of the salt solution is low, the internal resistance of the battery module is large, and the internal resistance loss increases; Fifth, the internal heat regeneration effect of the system is poor, and the system has large losses. Summary of the Invention

[0006] Based on this, an object of the present invention is to provide a dual-feed port hybrid working fluid reverse electrodialysis low-grade heat energy power generation system. This system uses a liquid distribution pipeline to lead the dilute and concentrated solutions to different feed ports of the generator respectively, so as to reduce or eliminate the dissipative losses generated in the heat transfer process and the solution mixing process; adopt an alternative solvent with a low boiling point and latent heat of vaporization to reduce the energy consumption and vacuum degree of the heat generation module; at the same time, introduce a regulator to adjust the conductivity of the solution, reduce the internal resistance loss, and give full play to the complementary advantages of the hybrid working fluid; in addition, the system structure is optimized, and multiple components inside the system are coupled to reduce the losses in the heat transfer process and the mixing process, and ensure a simple structure, reliable operation, and adjustable parameters.

[0007] A dual-feed port hybrid working fluid reverse electrodialysis low-grade heat energy power generation system includes a heat generation module, a working condition adjustment module connected to the heat generation module, and a concentration difference power generation module connected to the working condition adjustment module. The heat generation module includes a generator and a rectifier connected to the generator. The working condition adjustment module includes a solvent condenser, a dilute solution mixer, a dilute solution pump, and a temperature equalizer arranged in sequence, and also includes a regulator diverter, a regulator condenser, a concentrated solution mixer, a concentrated solution pump arranged in sequence, and a dilute solution throttle valve and a concentrated solution throttle valve connected to different outlets of the concentration difference power generation module; wherein,

[0008] The dilute solution and concentrated solution that have completed the power generation process in the concentration difference power generation module flow into the generator of the heat generation module through the dilute solution regulating valve and the concentrated solution regulating valve of the operating condition regulating module respectively. The generator is a double-feed inlet generator. The dilute solution and concentrated solution that have completed the power generation process undergo a regeneration process in the generator. The generator converts low-grade thermal energy into chemical potential energy to separate the dilute solution and concentrated solution that have completed the power generation process, generating a regulator and solvent vapor mixture and an initial concentrated solution. The regulator and solvent vapor mixture flows into the rectifier for rectification, outputs regulator vapor and solvent vapor respectively, and flows into the operating condition regulating module. At this point, the heat generation module completes the regeneration process;

[0009] The solvent vapor flows into the solvent condenser of the operating condition regulating module to be condensed and cooled to form a solvent liquid, the solvent liquid flows into the dilute solution mixer, and is mixed with the regulator liquid flowing into the dilute solution mixer, the initial concentrated solution, the dilute solution that has completed the power generation process, and one or more of the concentrated solutions that have completed the power generation process, to undergo a conductivity regulating process and a concentration regulating process to form a dilute solution, the dilute solution flows through the dilute solution pump and the thermostat in sequence to undergo a pressure regulating process and a temperature regulating process, respectively, and then flows into the concentration difference power generation module;

[0010] The regulator steam flows into the regulator splitter of the working condition regulating module and is split, with one part flowing into the dilute solution mixer or the heat generating module, and the other part flowing into the regulator condenser for condensation and cooling, and then flowing into the concentrated solution mixer after forming regulator liquid;

[0011] All or part of the initial concentrated solution flows into the concentrated solution mixer to mix with the regulator liquid, and forms a concentrated solution after undergoing conductivity adjustment process and concentration adjustment process; or part of the initial concentrated solution flows into the dilute solution mixer, and the other part flows into the concentrated solution mixer to mix with the regulator liquid, and forms a concentrated solution after undergoing conductivity adjustment process and concentration adjustment process, and the concentrated solution is sequentially subjected to pressure adjustment process and temperature adjustment process by the concentrated solution pump and the thermostat, and then flows into the concentration difference power generation module, and the operating condition adjustment process of the operating condition adjustment module is completed;

[0012] After the dilute solution and the concentrated solution flow into the concentration difference power generation module, the concentration difference power generation module performs reverse electrodialysis power generation based on the salt concentration difference between the dilute solution and the concentrated solution to convert chemical potential energy into electrical energy. At this point, the concentration difference power generation module completes the power generation process.

[0013] In an embodiment of the present invention, the operating condition adjustment module further includes a solvent regenerator connected to the rectifier and the solvent condenser, a regulator regenerator connected to the rectifier, the regulator diverter, and the first feed port of the generator, and a concentrated solution regenerator connected to the second feed port of the generator. Wherein the solvent vapor flows into the solvent condenser after being heat regenerated and cooled by the solvent regenerator, wherein the regulator vapor flows into the regulator diverter after being heat regenerated and cooled by the regulator regenerator, wherein the initial concentrated solution flows into the concentrated solution mixer after being heat regenerated and cooled by the concentrated solution regenerator, and wherein all or part of the dilute solution that has completed the power generation process in the concentration difference power generation module is sequentially heat regenerated and heated by the solvent regenerator, the rectifier, and the regulator regenerator, and then flows into the generator through the first feed port, and all or part of the concentrated solution that has completed the power generation process in the concentration difference power generation module is heat regenerated and heated by the concentrated solution regenerator and then flows into the generator through the second feed port.

[0014] In an embodiment of the present invention, the operating condition adjustment module further includes a dilute solution diverter connected to the dilute solution throttle valve, the dilute solution mixer, and the solvent regenerator. After the dilute solution that has completed the power generation process is throttled and depressurized by the dilute solution throttle valve and flows into the dilute solution diverter for diversion, a part of it flows into the dilute solution mixer, and the other part is sequentially heat regenerated and heated by the solvent regenerator, the rectifier, and the regulator regenerator, and then flows into the generator through the first feed port.

[0015] In an embodiment of the present invention, the operating condition adjustment module further includes a concentrated solution diverter connected to the dilute solution mixer, the concentrated solution mixer, and the concentrated solution regenerator. The initial concentrated solution after being heat regenerated by the concentrated solution regenerator flows into the concentrated solution diverter, and a part of it flows into the dilute solution mixer, and the other part flows into the concentrated solution mixer.

[0016] In an embodiment of the present invention, the operating condition adjustment module further includes a concentrated solution diverter connected to the concentrated solution throttle valve, the dilute solution mixer, and the concentrated solution regenerator. The concentrated solution that has completed the power generation process in the concentration difference power generation module flows into the concentrated solution diverter through the concentrated solution throttle valve, a part of it flows into the dilute solution mixer, and the other part flows into the concentrated solution regenerator for heat regeneration and heating, and then flows into the generator through the second feed port.

[0017] In an embodiment of the present invention, the operating condition adjustment module further includes a regulator mixer connected to the dilute solution diverter, the regulator diverter, and the solvent regenerator. A part of the dilute solution that has completed the power generation process output by the dilute solution diverter and a part of the regulator steam output by the regulator diverter flow into the regulator mixer for mixing. After that, they are sequentially heated and raised in temperature through the solvent regenerator, the rectifier, and the regulator regenerator, and then flow into the generator through the first feed port.

[0018] In an embodiment of the present invention, the operating condition adjustment module further includes a regulator mixer connected to the regulator diverter, the dilute solution throttle valve, and the solvent regenerator. A part of the regulator steam diverted by the regulator diverter flows into the regulator mixer, where it is mixed with the dilute solution that has completed the power generation process and flows in through the dilute solution throttle valve. After that, they are sequentially heated and raised in temperature through the solvent regenerator, the rectifier, and the regulator regenerator, and then flow into the generator through the first feed port.

[0019] In an embodiment of the present invention, the operating condition adjustment module further includes a dilute solution storage tank disposed between the dilute solution mixer and the dilute solution pump, and a concentrated solution storage tank disposed between the concentrated solution mixer and the concentrated solution pump. The dilute solution storage tank is used to adjust the flow rate of the dilute solution, and the concentrated solution storage tank is used to adjust the flow rate of the concentrated solution.

[0020] In an embodiment of the present invention, the dual-feed-port hybrid working fluid reverse electrodialysis low-grade heat energy power generation system uses a hybrid working fluid for power generation. The hybrid working fluid includes a solute, a regulator, and a solvent. The solute is composed of one or more pairs of anions and cations. The cations include lithium ions, sodium ions, magnesium ions, potassium ions, calcium ions, manganese ions, zinc ions, silver ions, iron ions, ferrous ions, aluminum ions, barium ions, copper ions, rubidium ions, cesium ions, strontium ions, hydrogen ions, ammonium ions; the anions include fluoride ions, chloride ions, bromide ions, iodide ions, carbonate ions, bicarbonate ions, sulfate ions, bisulfate ions, sulfite ions, bisulfite ions, cobaltate ions, silver nitrate ions, hypochlorite ions, perchlorate ions, manganate ions, oxalate ions, acetate ions, hydrocyanate ions, formate ions, phosphate ions, phosphite ions, benzoate ions, sulfide ions, chromate ions;

[0021] Or the solute is composed of one or more liquids, and the liquids include water, ethanol, methanol, gasoline, diesel, kerosene, acetonitrile, ether, acetone, isopropanol, hexafluoroisopropanol, trifluoroethanol, trifluoroacetic acid, tetrahydrofuran, dimethylformamide, dimethylacetamide;

[0022] The regulator is composed of one or more of water, formamide, trifluoroacetic acid, DMSO, acetonitrile, DMF, hexamethylphosphoramide, methanol, ethanol, acetic acid, isopropanol, pyridine, tetramethylethylenediamine, acetone, triethylamine, n-butanol, dioxane, tetrahydrofuran, methyl formate, tributylamine, methyl ethyl ketone, ethyl acetate, chloroform, trioctylamine, dimethyl carbonate, ether, isopropyl ether, n-butyl ether, trichloroethylene, diphenyl ether, dichloromethane, dichloroethane, toluene, carbon tetrachloride, carbon disulfide, cyclohexane, hexane, and kerosene;

[0023] The solvent is composed of one or more of water, formamide, trifluoroacetic acid, DMSO, acetonitrile, DMF, hexamethylphosphoramide, methanol, ethanol, acetic acid, isopropanol, pyridine, tetramethylethylenediamine, acetone, triethylamine, n-butanol, dioxane, tetrahydrofuran, methyl formate, tributylamine, methyl ethyl ketone, ethyl acetate, chloroform, trioctylamine, dimethyl carbonate, ether, isopropyl ether, n-butyl ether, trichloroethylene, diphenyl ether, dichloromethane, dichloroethane, toluene, carbon tetrachloride, carbon disulfide, cyclohexane, hexane, and kerosene.

[0024] In an embodiment of the present invention, the concentration difference power generation module includes a reverse electrodialysis cell stack and an external circuit electrically connected to the reverse electrodialysis cell stack. The reverse electrodialysis cell stack includes an ion exchange membrane and an electrode system. The ion exchange membrane is used to enable the dilute solution and the concentrated solution output by the working condition adjustment module to simultaneously flow and mass transfer, so as to form a directional ion flow on both sides. The electrode system is used to convert the directional ion flow into an electron flow and output electric energy through the external circuit.

[0025] In an embodiment of the present invention, the ion exchange membrane includes one or more cation exchange membranes and one or more anion exchange membranes, and the cation exchange membranes and anion exchange membranes are arranged alternately.

[0026] In an embodiment of the present invention, the reverse electrodialysis cell stack adopts any one of the arrangement forms of a single unit, multiple units in series, multiple units in parallel, or a hybrid of multiple units in series and parallel. The electrode system adopts an active electrode or an inert electrode, including any one of a lithium electrode, a carbon electrode, a carbon rod electrode, a platinum electrode, a titanium electrode, and a copper electrode; the electrode solution is a separate redox working fluid pair or the dilute solution and the concentrated solution.

[0027] In an embodiment of the present invention, the generator has an upper outlet and a lower outlet. The vapor mixture of the regulator and the solvent flows into the rectifier through the upper outlet of the generator, and the concentrated solution flows into the working condition adjustment module through the lower outlet of the generator.

[0028] In an embodiment of the present invention, the rectifier has an upper port and a lower port. The regulator steam flows into the working condition adjustment module through the lower port of the rectifier, and the solvent steam flows into the working condition adjustment module through the upper port of the rectifier.

[0029] In an embodiment of the present invention, the rectifier has an upper port and a lower port. The regulator steam flows into the working condition adjustment module through the upper port of the rectifier, and the solvent steam flows into the working condition adjustment module through the lower port of the rectifier.

[0030] In an embodiment of the present invention, the temperature equalizer is a two-stream heat exchange type temperature equalizer or a three-stream heat exchange type temperature equalizer.

[0031] In an embodiment of the present invention, the dilute solution pump and the concentrated solution pump are any one of volumetric, dynamic, and diaphragm types, and adopt any one of the arrangement forms of single unit, multiple units in series, multiple units in parallel, or a hybrid of multiple units in series and parallel.

[0032] In an embodiment of the present invention, the solvent condenser and the regulator condenser use any one of the heat exchange methods of natural air convection heat transfer, forced air convection heat transfer, mixed air convection heat transfer, radiation heat transfer, natural liquid convection heat transfer, and forced liquid convection heat transfer, and adopt any one of the arrangement forms of single unit, multiple units in series, multiple units in parallel, or a hybrid of multiple units in series and parallel.

[0033] The beneficial effects of the present invention are as follows:

[0034] The dual-feed port hybrid working fluid reverse electrodialysis low-grade heat energy power generation system of the present invention uses the reverse electrodialysis technology to convert low-grade waste heat into chemical potential energy, and uses the concentration difference between salt solutions to convert the chemical potential energy into electrical energy, realizing the efficient recovery and utilization of low-grade waste heat, which is beneficial to improving the overall utilization efficiency of waste heat resources.

[0035] The dual-feed port hybrid working fluid reverse electrodialysis low-grade heat energy power generation system of the present invention uses a hybrid working fluid, and no other harmful substances will be generated during the power generation process, which is pollution-free to the environment, environmentally friendly, and the hybrid working fluid can be recycled for power generation, realizing the cyclic recovery and utilization of low-grade waste heat.

[0036] The dual-feed port hybrid working fluid reverse electrodialysis low-grade heat energy power generation system of the present invention uses a liquid distribution pipeline to lead dilute and concentrated solutions to different feed ports of the generator respectively, reducing or eliminating the dissipation loss generated during the solution mixing process.

[0037] The hybrid working fluid reverse electrodialysis low-grade heat energy power generation system with double feed inlets of the present invention also introduces a solvent and a regulator. A solution with low boiling point and low latent heat of vaporization is used as the solvent, which is beneficial to reducing the energy consumption and vacuum degree of the heat generation module. At the same time, a regulator is used to adjust the conductivity of the solution, which is beneficial to increasing the conductivity of the salt solution, thereby reducing the internal resistance loss and giving full play to the complementary advantages of the hybrid working fluid. In addition, the structure of the whole system is optimized to ensure simple structure, reliable operation, adjustable parameters and good regenerative effect.

[0038] The system structure of the hybrid working fluid reverse electrodialysis low-grade heat energy power generation system with double feed inlets of the present invention is simple and has no moving parts. Its core components such as ion exchange membranes and generators have mature applications in both the electrodialysis industry and the distillation separation industry. Therefore, this technology is more easily productized and put into actual industrial production.

[0039] Through the understanding of the subsequent description and drawings, the further objectives and advantages of the present invention will be fully reflected. Brief Description of the Drawings

[0040] Figure 1 Schematic structural diagram of the hybrid working fluid reverse electrodialysis low-grade heat energy power generation system with double feed inlets provided for the first embodiment of the present invention;

[0041] Figure 2 Schematic structural diagram of the hybrid working fluid reverse electrodialysis low-grade heat energy power generation system with double feed inlets provided for the second embodiment of the present invention;

[0042] Figure 3 Schematic structural diagram of the hybrid working fluid reverse electrodialysis low-grade heat energy power generation system with double feed inlets provided for the third embodiment of the present invention;

[0043] Figure 4 Schematic structural diagram of the hybrid working fluid reverse electrodialysis low-grade heat energy power generation system with double feed inlets provided for the fourth embodiment of the present invention;

[0044] Figure 5 Schematic structural diagram of the hybrid working fluid reverse electrodialysis low-grade heat energy power generation system with double feed inlets provided for the fifth embodiment of the present invention;

[0045] Figure 6 Schematic structural diagram of the hybrid working fluid reverse electrodialysis low-grade heat energy power generation system with double feed inlets provided for the sixth embodiment of the present invention;

[0046] Figure 7 Schematic structural diagram of the hybrid working fluid reverse electrodialysis low-grade heat energy power generation system with double feed inlets provided for the seventh embodiment of the present invention;

[0047] Figure 8Schematic diagram of the structure of a low-grade thermal energy power generation system with a dual-feed inlet and a reverse electrodialysis of mixed working fluids provided by the eighth embodiment of the present invention;

[0048] Figure 9 Schematic diagram of the structure of a low-grade thermal energy power generation system with a dual-feed inlet and a reverse electrodialysis of mixed working fluids provided by the ninth embodiment of the present invention;

[0049] Figure 10 Schematic diagram of the structure of a low-grade thermal energy power generation system with a dual-feed inlet and a reverse electrodialysis of mixed working fluids provided by the tenth embodiment of the present invention;

[0050] Figure 11 Schematic diagram of the structure of a low-grade thermal energy power generation system with a dual-feed inlet and a reverse electrodialysis of mixed working fluids provided by the eleventh embodiment of the present invention;

[0051] Figure 12 Schematic diagram of the structure of a low-grade thermal energy power generation system with a dual-feed inlet and a reverse electrodialysis of mixed working fluids provided by the twelfth embodiment of the present invention;

[0052] Explanation of the reference numerals in the drawings: Generator 1, Rectifier 2, Solvent Regenerator 3, Solvent Condenser 4, Dilute Solution Mixer 5, Dilute Solution Storage Tank 6, Dilute Solution Pump 7, Temperature Equalizer 8, Modulator Regenerator 9, Modulator Divider 10, Modulator Condenser 11, Concentrated Solution Mixer 12, Concentrated Solution Storage Tank 13, Concentrated Solution Pump 14, Concentrated Solution Regenerator 15, Reverse Electrodialysis Cell Stack 16, Ion Exchange Membrane 16a, Electrode System 16b, External Circuit 17, Dilute Solution Throttle Valve 18, Dilute Solution Divider 19, Concentrated Solution Throttle Valve 20, Concentrated Solution Divider 21, Modulator Mixer 22. In the drawings, the arrow direction indicates the solution flow direction. Detailed Description of the Preferred Embodiments

[0053] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and other obvious variations can be conceived by those skilled in the art. The basic principles defined in the following description can be applied to other embodiments, deformation schemes, improvement schemes, equivalent schemes, and other technical schemes without departing from the spirit and scope of the present invention.

[0054] Those skilled in the art should understand that in the disclosure of the present invention, the orientation or positional relationships indicated by the terms "vertical", "horizontal", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings. These are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limiting the present invention.

[0055] It is understood that the term "a" should be understood as "at least one" or "one or more". That is, in one embodiment, the number of an element can be one, while in other embodiments, the number of the element can be multiple. The term "a" should not be understood as a limitation on the quantity.

[0056] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "mounted", "connected", and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a connection that allows mutual communication; it can be a direct connection, or an indirect connection through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0057] In the field of reverse electrodialysis heat engine technology, the factors restricting the efficiency of reverse electrodialysis heat engines mainly include two points. One is that the heat generation module consumes a high amount of energy. Specifically, due to the large latent heat of vaporization of the solute, the conversion efficiency of "heat-chemical potential energy" is restricted. The other is that when using a solute with a low latent heat of vaporization, usually the solute has poor conductivity, resulting in a large internal resistance of the battery unit and a large ohmic loss. Since the existing reverse electrodialysis heat engine technology generally uses water as a solvent and uses a single working fluid for power generation, there are problems such as high energy consumption of the heat generation module, large internal resistance of the battery module, and large losses. In addition, because the existing reverse electrodialysis heat engine technology directly mixes the dilute solution and the concentrated solution and then returns them to the heat generation module for the regeneration process during cyclic power generation, there is a problem of generating dissipation losses. All these lead to a relatively low overall utilization efficiency of waste heat resources.

[0058] To solve the above problems, the present application provides a dual-feed port hybrid working fluid reverse electrodialysis low-grade heat energy power generation system. This system uses a liquid distribution pipeline to lead the dilute solution and the concentrated solution to different feed ports of the heat generation module respectively, so as to reduce or eliminate the dissipation losses generated during the heat transfer process and the solution mixing process; uses a substitute solvent with a low boiling point and latent heat of vaporization to reduce the energy consumption and vacuum degree of the heat generation module; at the same time, introduces a regulator to adjust the solution conductivity and reduce the internal resistance loss, giving full play to the complementary advantages of the hybrid working fluid; in addition, the system structure is optimized, and multiple components inside the system are coupled to reduce the losses during the heat transfer process and the mixing process, and ensure a simple structure, reliable operation, and adjustable parameters.

[0059] As Figure 1As shown, the specific structure of a dual-feed mixed working fluid reverse electrodialysis low-grade heat energy power generation system provided by the first embodiment of the present invention is illustrated. Specifically, the dual-feed mixed working fluid reverse electrodialysis low-grade heat energy power generation system includes a heat generation module, a working condition adjustment module connected to the heat generation module, and a concentration difference power generation module connected to the working condition adjustment module. The concentration difference power generation module is used for reverse electrodialysis power generation based on the salt concentration difference between the dilute solution and the concentrated solution. The dilute solution and the concentrated solution that have completed the power generation process in the concentration difference power generation module flow into the heat generation module from different feed ports through the working condition adjustment module for the regeneration process. The heat generation module is arranged to be driven by low-grade heat energy and is used to convert low-grade heat energy into chemical potential energy generated by the concentration difference between salt solutions, so as to separate the dilute solution and the concentrated solution that have completed the power generation process into regulator steam, solvent steam, and the initial concentrated solution. The working condition adjustment module is used to respectively perform conductivity adjustment, temperature adjustment, pressure adjustment, and flow adjustment on the regulator steam, the solvent steam, and the initial concentrated solution, so as to output the dilute solution and the concentrated solution to the concentration difference power generation module for reverse electrodialysis power generation, thereby completing the power generation cycle.

[0060] It can be understood that the principle of power generation of the dual-feed mixed working fluid reverse electrodialysis low-grade heat energy power generation system is as follows: The heat generation module is used to convert low-grade heat energy into chemical potential energy generated by the concentration difference between salt solutions, and the reverse electrodialysis technology is utilized, that is, the chemical potential energy is converted into electrical energy by using the salt concentration difference between the dilute solution and the concentrated solution, realizing the efficient recovery and utilization of low-grade waste heat, which is beneficial to improving the overall utilization efficiency of waste heat resources.

[0061] Furthermore, the heat generation module includes a generator 1 and a rectifier 2 connected to the generator 1. The working condition adjustment module includes a solvent condenser 4, a dilute solution mixer 5, a dilute solution pump 7, and a temperature equalizer 8 arranged in sequence, and also includes a regulator splitter 10, a regulator condenser 11, a concentrated solution mixer 12, a concentrated solution pump 14 arranged in sequence, and a dilute solution throttle valve 18 and a concentrated solution throttle valve 20 connected to different outlets of the concentration difference power generation module. The dual-feed mixed working fluid reverse electrodialysis low-grade heat energy power generation system includes a regeneration process, a working condition adjustment process, and a power generation process. Specifically, the dual-feed mixed working fluid reverse electrodialysis low-grade heat energy power generation system uses the heat generation module to complete the regeneration process, uses the working condition adjustment module to complete the working condition adjustment process, and uses the concentration difference power generation module to complete the power generation process.

[0062] More specifically, the cyclic power generation process of the dual-feed mixed working fluid reverse electrodialysis low-grade heat energy power generation system is as follows:

[0063] The dilute solution and the concentrated solution that complete the power generation process in the concentration difference power generation module respectively flow into the generator 1 of the heat generation module through the dilute solution regulating valve and the concentrated solution regulating valve of the working condition regulating module. The generator 1 is a double-feed inlet generator. The dilute solution and the concentrated solution that complete the power generation process carry out a regeneration process in the generator 1. The generator 1 converts low-grade heat energy into chemical potential energy to separate the dilute solution and the concentrated solution that have completed the power generation process, generating a mixture of a regulator and a solvent vapor and an initial concentrated solution. The mixture of the regulator and the solvent vapor flows into the rectifier 2 for rectification, and the regulator vapor and the solvent vapor are respectively output and flow into the working condition regulating module. Thus, the heat generation module completes the regeneration process;

[0064] The solvent vapor flows into the solvent condenser 4 of the working condition regulating module for condensation and cooling to form a solvent liquid. The solvent liquid flows into the dilute solution mixer 5 and is mixed with one or more of the regulator liquid, the initial concentrated solution, the dilute solution that has completed the power generation process, and the concentrated solution that has completed the power generation process flowing into the dilute solution mixer 5 to carry out a conductivity adjustment process and a concentration adjustment process to form a dilute solution. The dilute solution sequentially flows through the dilute solution pump 7 and the temperature equalizer 8 to respectively carry out a pressure adjustment process and a temperature adjustment process, and then flows into the concentration difference power generation module;

[0065] The regulator vapor flows into the regulator diverter 10 of the working condition regulating module for diversion. A part flows into the dilute solution mixer 5 or the heat generation module, and the other part flows into the regulator condenser 11 for condensation and cooling. After forming a regulator liquid, it flows into the concentrated solution mixer 12;

[0066] All or part of the initial concentrated solution flows into the concentrated solution mixer 12 and is mixed with the regulator liquid. After carrying out a conductivity adjustment process and a concentration adjustment process, a concentrated solution is formed; or a part of the initial concentrated solution flows into the dilute solution mixer 5, and the other part flows into the concentrated solution mixer 12 and is mixed with the regulator liquid. After carrying out a conductivity adjustment process and a concentration adjustment process, a concentrated solution is formed. The concentrated solution sequentially undergoes a pressure adjustment process and a temperature adjustment process through the concentrated solution pump 14 and the temperature equalizer 8 respectively, and then flows into the concentration difference power generation module. Thus, the working condition regulating module completes the working condition regulation process;

[0067] After the dilute solution and the concentrated solution flow into the concentration difference power generation module, the concentration difference power generation module carries out reverse electrodialysis power generation based on the salt concentration difference between the dilute solution and the concentrated solution, converting chemical potential energy into electrical energy. Thus, the concentration difference power generation module completes the power generation process.

[0068] It is worth mentioning that, in the first embodiment of the present invention, all of the initial concentrated solution flows into the concentrated solution mixer 12 to be mixed with the regulator liquid, and after the conductivity adjustment process and the concentration adjustment process, the concentrated solution is formed.

[0069] It is also worth mentioning that the temperature equalizer 8 is a two-stream heat exchange type temperature equalizer or a three-stream heat exchange type temperature equalizer. In other words, the temperature equalizer 8 can adopt the two-stream heat exchange form, or a third fluid can be introduced to adjust the temperature of the solution, and the present invention does not limit this.

[0070] In addition, it is worth mentioning that the dilute solution pump 7 and the concentrated solution pump 14 can be any one of volumetric, dynamic and diaphragm types, and can adopt any one of the arrangement forms of single unit, multiple units in series, multiple units in parallel or a hybrid of multiple units in series and parallel. In other words, the dilute solution pump 7 and the concentrated solution pump 14 can be selected from volumetric, dynamic and diaphragm types, and can adopt the arrangement forms of single unit, multiple units in series, multiple units in parallel or a hybrid of multiple units in series and parallel.

[0071] In addition, the solvent condenser 4 and the regulator condenser 11 exchange heat by any one of the heat exchange methods of natural air convection heat exchange, forced air convection heat exchange, mixed air convection heat exchange, radiation heat exchange, natural liquid convection heat exchange and forced liquid convection heat exchange, and adopt any one of the arrangement forms of single unit, multiple units in series, multiple units in parallel or a hybrid of multiple units in series and parallel.

[0072] In other words, the solvent condenser 4 and the regulator condenser 11 can exchange heat with the outside world in different ways, including natural air convection heat exchange, forced air convection heat exchange, mixed air convection heat exchange, radiation heat exchange, natural liquid convection heat exchange and forced liquid convection heat exchange, and can adopt the arrangement forms of single unit, multiple units in series, multiple units in parallel or a hybrid of multiple units in series and parallel.

[0073] It is worth mentioning that when the solvent condenser 4 and the regulator condenser 11 adopt forced convection heat exchange, the hot and cold fluids can exchange heat in the forms of co-current flow, counter-current flow and cross flow.

[0074] Further, the operating condition adjustment module further includes a solvent regenerator 3 connected to the rectifier 2 and the solvent condenser 4, a regulator regenerator 9 connected to the rectifier 2, the regulator diverter 10, and the first feed port of the generator 1, and a concentrated solution regenerator 15 connected to the second feed port of the generator 1. The solvent vapor flows into the solvent condenser 4 after being heat regenerated and cooled by the solvent regenerator 3. The regulator vapor flows into the regulator diverter 10 after being heat regenerated and cooled by the regulator regenerator 9. The initial concentrated solution flows into the concentrated solution mixer 12 after being heat regenerated and cooled by the concentrated solution regenerator 15. All or part of the dilute solution that has completed the power generation process in the concentration difference power generation module is heat regenerated and heated by passing through the solvent regenerator 3, the rectifier 2, and the regulator regenerator 9 in sequence, and then flows into the generator 1 through the first feed port. All or part of the concentrated solution that has completed the power generation process in the concentration difference power generation module is heat regenerated and heated by the concentrated solution regenerator 15 and then flows into the generator 1 through the second feed port.

[0075] It should be understood that the dilute solution that has completed the power generation process can flow through one or more of the rectifier 2, the solvent regenerator 3, the regulator regenerator 9, and the concentrated solution regenerator 15 in any order for the heat regeneration process; the concentrated solution that has completed the power generation process can also flow through one or more of the rectifier 2, the solvent regenerator 3, the regulator regenerator 9, and the concentrated solution regenerator 15 in any order for the heat regeneration process, and the present invention does not limit this.

[0076] Furthermore, the operating condition adjustment module further includes a dilute solution diverter 19 connected to the dilute solution throttle valve 18, the dilute solution mixer 5, and the solvent regenerator 3. After the dilute solution that has completed the power generation process is throttled and depressurized by the dilute solution throttle valve 18 and flows into the dilute solution diverter 19 for diversion, a part of it flows into the dilute solution mixer 5, and the other part is heat regenerated and heated by passing through the solvent regenerator 3, the rectifier 2, and the regulator regenerator 9 in sequence, and then flows into the generator 1 through the first feed port.

[0077] That is to say, in the first embodiment of the present invention, part of the dilute solution that has completed the power generation process in the concentration difference power generation module flows into the generator 1 for the regeneration process. And all of the concentrated solution that has completed the power generation process in the concentration difference power generation module flows into the generator 1 for the regeneration process.

[0078] It can be understood that since the dilute solution and the concentrated solution that have completed the power generation process in the hybrid working fluid reverse electrodialysis low-grade heat energy power generation system with the double feed ports flow into the generator 1 through the first feed port and the second feed port respectively for the regeneration process, it is possible to avoid the energy consumption loss generated by direct mixing before entering the generator 1, which is beneficial to reducing the overall energy consumption of the hybrid working fluid reverse electrodialysis low-grade heat energy power generation system with the double feed ports, and thus is beneficial to improving the overall utilization efficiency of low-grade heat energy.

[0079] In other words, by setting up two liquid distribution pipelines and combining with the coupling method of one or more components among the dilute solution throttle valve 18, the dilute solution diverter 19, and the concentrated solution diverter 21, the present invention leads the dilute solution and the concentrated solution that have completed the power generation process to different feed ports of the generator 1 respectively, which can reduce or eliminate the dissipation loss generated in the heat transfer process and the solution mixing process, and thus is beneficial to improving the overall utilization efficiency of the waste heat resources of the entire system.

[0080] Furthermore, the operating condition adjustment module further includes a dilute solution storage tank 6 arranged between the dilute solution mixer 5 and the dilute solution pump 7, and a concentrated solution storage tank 13 arranged between the concentrated solution mixer 12 and the concentrated solution pump 14. The dilute solution storage tank 6 is used to adjust the flow rate of the dilute solution, and the concentrated solution storage tank 13 is used to adjust the flow rate of the concentrated solution, so that the hybrid working fluid reverse electrodialysis low-grade heat energy power generation system with the double feed ports can store energy and potential energy and ensure the stability of power generation.

[0081] Particularly, the hybrid working fluid reverse electrodialysis low-grade heat energy power generation system with the double feed ports uses a hybrid working fluid for power generation. The hybrid working fluid includes a solute, a regulator, and a solvent. The solute is composed of one or more pairs of anions and cations. The cations include lithium ions, sodium ions, magnesium ions, potassium ions, calcium ions, manganese ions, zinc ions, silver ions, iron ions, ferrous ions, aluminum ions, barium ions, copper ions, rubidium ions, cesium ions, strontium ions, hydrogen ions, ammonium ions; the anions include fluoride ions, chloride ions, bromide ions, iodide ions, carbonate ions, bicarbonate ions, sulfate ions, bisulfate ions, sulfite ions, bisulfite ions, cobaltate ions, silver nitrate ions, hypochlorite ions, perchlorate ions, manganate ions, oxalate ions, acetate ions, hydrocyanate ions, formate ions, phosphate ions, phosphite ions, benzoate ions, sulfide ions, chromate ions;

[0082] Alternatively, the solute consists of one or more liquids, including water, ethanol, methanol, gasoline, diesel, kerosene, acetonitrile, ether, acetone, isopropanol, hexafluoroisopropanol, trifluoroethanol, trifluoroacetic acid, tetrahydrofuran, dimethylformamide, and dimethylacetamide.

[0083] The regulator consists of one or more of water, formamide, trifluoroacetic acid, DMSO, acetonitrile, DMF, hexamethylphosphoramide, methanol, ethanol, acetic acid, isopropanol, pyridine, tetramethylethylenediamine, acetone, triethylamine, n-butanol, dioxane, tetrahydrofuran, methyl formate, tributylamine, methyl ethyl ketone, ethyl acetate, chloroform, trioctylamine, dimethyl carbonate, ether, isopropyl ether, n-butyl ether, trichloroethylene, diphenyl ether, dichloromethane, dichloroethane, toluene, carbon tetrachloride, carbon disulfide, cyclohexane, hexane, and kerosene.

[0084] The solvent consists of one or more of water, formamide, trifluoroacetic acid, DMSO, acetonitrile, DMF, hexamethylphosphoramide, methanol, ethanol, acetic acid, isopropanol, pyridine, tetramethylethylenediamine, acetone, triethylamine, n-butyl ether, dioxane, tetrahydrofuran, methyl formate, tributylamine, methyl ethyl ketone, ethyl acetate, chloroform, trioctylamine, dimethyl carbonate, ether, isopropyl ether, n-butyl ether, trichloroethylene, diphenyl ether, dichloromethane, dichloroethane, toluene, carbon tetrachloride, carbon disulfide, cyclohexane, hexane, and kerosene.

[0085] It is worth mentioning that the concentration range of the dilute solution in the present invention is from zero to less than the saturation concentration of the solution, and the concentration range of the concentrated solution is from greater than zero to the saturation concentration. The present invention does not limit the specific concentrations of the dilute solution and the concentrated solution.

[0086] It can be understood that the dual-feed inlet hybrid working fluid reverse electrodialysis low-grade heat energy power generation system uses an alternative solvent with low boiling point and latent heat of vaporization, which is beneficial to reducing the energy consumption and vacuum degree of the heat generation module. Moreover, the dual-feed inlet hybrid working fluid reverse electrodialysis low-grade heat energy power generation system also introduces a regulator to adjust the solution conductivity, which is beneficial to reducing the internal resistance loss of the concentration difference power generation module. In addition, the system structure is optimized, and the internal use of multiple components coupling reduces the heat transfer process and mixing process losses, ensuring a simple structure, reliable operation, adjustable parameters, and good heat regeneration effect.

[0087] Furthermore, the concentration difference power generation module includes a reverse electrodialysis cell stack 16 and an external circuit 17 electrically connected to the reverse electrodialysis cell stack 16. The reverse electrodialysis cell stack 16 includes an ion exchange membrane 16a and an electrode system 16b. The ion exchange membrane 16a is used to enable the dilute solution and the concentrated solution output by the working condition adjustment module to simultaneously flow and mass transfer processes, so as to form a directional ion flow on both sides. The electrode system 16b is used to convert the directional ion flow into an electron flow and output electrical energy through the external circuit 17.

[0088] Specifically, the ion exchange membrane 16a includes one or more cation exchange membranes and one or more anion exchange membranes, and the cation exchange membranes and anion exchange membranes are arranged alternately. Moreover, the cation exchange membranes and the anion exchange membranes may appear in pairs or not in pairs, and the number may be one or more. The present invention does not limit this.

[0089] It is worth mentioning that the reverse electrodialysis cell stack 16 adopts any one of the arrangement forms of a single unit, multiple units in series, multiple units in parallel, or a hybrid of multiple units in series and parallel. The electrode system 16b is an active electrode or an inert electrode, including any one of a lithium electrode, a carbon electrode, a carbon rod electrode, a platinum electrode, a titanium electrode, and a copper electrode; the electrode solution is a separate redox working medium pair or the dilute solution and the concentrated solution.

[0090] Furthermore, the generator 1 has an upper outlet and a lower outlet. The mixture of the regulator and the solvent flows into the rectifier 2 through the upper outlet of the generator 1, and the concentrated solution flows into the working condition adjustment module through the lower outlet of the generator 1.

[0091] In addition, it is also worth mentioning that in this embodiment of the present invention, the rectifier 2 has an upper port and a lower port. The regulator vapor flows into the working condition adjustment module through the lower port of the rectifier 2, and the solvent vapor flows into the working condition adjustment module through the upper port of the rectifier 2.

[0092] In some embodiments of the present invention, such as in the seventh to twelfth embodiments, when the boiling point of the regulator is higher than the boiling point of the solvent, the regulator vapor flows into the regulator recuperator 9 of the working condition adjustment module through the upper port of the rectifier 2, and the solvent vapor flows into the solvent recuperator 3 of the working condition adjustment module through the lower port of the rectifier 2. That is to say, the dual-feed port hybrid working medium reverse electrodialysis low-grade heat energy power generation system of the present invention is applicable to the case where the boiling point of the regulator is higher than the boiling point of the solvent.

[0093] It can be understood that in this embodiment of the present invention, the dilute solution is formed by the solvent liquid, a part of the regulator vapor, and a part of the dilute solution that has completed the power generation process; all of the initial concentrated solution flows into the concentrated solution mixer 12 and is mixed with the regulator liquid to form the concentrated solution.

[0094] As Figure 2 shown, the specific structure of a dual-feed port hybrid working fluid reverse electrodialysis low-grade thermal energy power generation system provided according to the second embodiment of the present invention is elucidated. The second embodiment is a variant embodiment of the first embodiment. Specifically, different from the first embodiment, the operating condition adjustment module further includes a regulator mixer 22 connected to the dilute solution splitter 19, the regulator splitter 10, and the solvent regenerator 3. A part of the dilute solution that has completed the power generation process output by the dilute solution splitter 19 and a part of the regulator vapor output by the regulator splitter 10 flow into the regulator mixer 22 and are mixed. Then, after being regenerated and heated in sequence through the solvent regenerator 3, the rectifier 2, and the regulator regenerator 9, they flow into the generator 1 through the first feed port.

[0095] That is to say, in the second embodiment, the dilute solution is formed by the solvent liquid and a part of the dilute solution that has completed the power generation process; a part of the regulator vapor output by the regulator splitter 10 and another part of the dilute solution that has completed the power generation process flow into the regulator mixer 22 and are mixed. Then, after being regenerated and heated in sequence through the solvent regenerator 3, the rectifier 2, and the regulator regenerator 9, they flow into the generator 1 through the first feed port.

[0096] As Figure 3 shown, the specific structure of a dual-feed port hybrid working fluid reverse electrodialysis low-grade thermal energy power generation system provided according to the third embodiment of the present invention is elucidated. The third embodiment is a variant embodiment of the first embodiment. Specifically, different from the first embodiment, the operating condition adjustment module further includes a concentrated solution splitter 21 connected to the concentrated solution throttle valve 20, the dilute solution mixer 5, and the concentrated solution regenerator 15. The concentrated solution that has completed the power generation process in the concentration difference power generation module flows into the concentrated solution splitter 21 through the concentrated solution throttle valve 20. A part flows into the dilute solution mixer 5, and another part flows into the concentrated solution regenerator 15 for regeneration and heating, and then flows into the generator 1 through the second feed port.

[0097] Moreover, in the third embodiment, the operating condition adjustment module does not include the dilute solution splitter 19. That is to say, in the third embodiment, all of the dilute solution that has completed the power generation process is sequentially regenerated and heated through the solvent regenerator 3, the rectifier 2, and the regulator regenerator 9, and then flows into the generator 1 through the first feed port.

[0098] It can be understood that in the third embodiment, the dilute solution is formed by the solvent liquid, a part of the regulator vapor, and a part of the concentrated solution that has completed the power generation process. The concentrated solution is formed by mixing all of the initial concentrated solution and the regulator liquid flowing into the concentrated solution mixer 12.

[0099] As Figure 4 shown, the specific structure of a dual-feed port hybrid working fluid reverse electrodialysis low-grade heat energy power generation system provided according to the fourth embodiment of the present invention is illustrated. The fourth embodiment is a modified embodiment of the third embodiment. Specifically, different from the third embodiment, the concentrated solution diverter 21 of the operating condition adjustment module is connected to the dilute solution mixer 5, the concentrated solution mixer 12, and the concentrated solution regenerator 15. The initial concentrated solution after heat treatment flowing back from the concentrated solution regenerator 15 flows into the concentrated solution diverter 21, with a part flowing into the dilute solution mixer 5 and another part flowing into the concentrated solution mixer 12.

[0100] That is to say, in the fourth embodiment, the concentrated solution diverter 21 is used to divert the initial concentrated solution, rather than the concentrated solution that has completed the power generation process.

[0101] It should be understood that in the fourth embodiment, the dilute solution is formed by the solvent liquid, a part of the regulator vapor, and a part of the initial concentrated solution, and the concentrated solution is formed by mixing a part of the initial concentrated solution and the regulator liquid.

[0102] As Figure 5 shown, the specific structure of a dual-feed port hybrid working fluid reverse electrodialysis low-grade heat energy power generation system provided according to the fifth embodiment of the present invention is illustrated. The fifth embodiment is another modified embodiment of the third embodiment. Specifically, different from the third embodiment, the operating condition adjustment module further includes a regulator mixer 22 connected to the regulator diverter 10, the dilute solution throttle valve 18, and the solvent regenerator 3. A part of the regulator vapor diverted by the regulator diverter 10 flows into the regulator mixer 22, where it is mixed with the dilute solution that has completed the power generation process and flows in through the dilute solution throttle valve 18. After being heated and regenerated successively through the solvent regenerator 3, the rectifier 2, and the regulator regenerator 9, it flows into the generator 1 through the first feed port.

[0103] That is to say, in the fifth embodiment, the dilute solution is formed by the solvent liquid and a part of the concentrated solution that has completed the power generation process, and the concentrated solution is formed by mixing all of the initial concentrated solution and the regulator liquid flowing into the concentrated solution mixer 12.

[0104] As Figure 6As shown, the specific structure of a dual-feed inlet hybrid working fluid reverse electrodialysis low-grade thermal energy power generation system provided according to the sixth embodiment of the present invention is elucidated. The sixth embodiment is a variant embodiment of the fourth embodiment. Specifically, different from the fourth embodiment, the operating condition adjustment module further includes a regulator mixer 22 connected to the regulator splitter 10, the dilute solution throttle valve 18, and the solvent regenerator 3. A part of the regulator steam split by the regulator splitter 10 flows into the regulator mixer 22, where it is mixed with the dilute solution that has completed the power generation process and flows in through the dilute solution throttle valve 18. After that, it is successively heated and temperature-raised through the solvent regenerator 3, the rectifier 2, and the regulator regenerator 9, and then flows into the generator 1 through the first feed inlet.

[0105] It can be understood that in the sixth embodiment, the dilute solution is formed by the solvent liquid and a part of the initial concentrated solution, and the concentrated solution is formed by mixing another part of the initial concentrated solution and the regulator liquid flowing into the concentrated solution mixer 12.

[0106] As Figure 7 shown, the specific structure of a dual-feed inlet hybrid working fluid reverse electrodialysis low-grade thermal energy power generation system provided according to the seventh embodiment of the present invention is elucidated. The seventh embodiment is a variant embodiment of the first embodiment. Specifically, different from the first embodiment, the boiling point of the regulator adopted in the seventh embodiment is higher than that of the solvent. Therefore, in the seventh embodiment, the regulator steam flows into the regulator regenerator 9 of the operating condition adjustment module from the upper port of the rectifier 2, and the solvent steam flows into the solvent regenerator 3 from the lower port of the rectifier 2.

[0107] As Figure 8 shown, the specific structure of a dual-feed inlet hybrid working fluid reverse electrodialysis low-grade thermal energy power generation system provided according to the eighth embodiment of the present invention is elucidated. The eighth embodiment is a variant embodiment of the second embodiment. Specifically, different from the second embodiment, the boiling point of the regulator adopted in the eighth embodiment is higher than that of the solvent. Therefore, in the eighth embodiment, the regulator steam flows into the regulator regenerator 9 of the operating condition adjustment module from the upper port of the rectifier 2, and the solvent steam flows into the solvent regenerator 3 from the lower port of the rectifier 2.

[0108] As Figure 9As shown, the specific structure of a dual-feed mixed working fluid reverse electrodialysis low-grade heat energy power generation system provided according to the ninth embodiment of the present invention is elucidated. The ninth embodiment is a variant embodiment of the third embodiment. Specifically, different from the third embodiment, the boiling point of the regulator adopted in the ninth embodiment is higher than that of the solvent. Therefore, in the ninth embodiment, the regulator vapor flows into the regulator recuperator 9 of the operating condition adjustment module from the upper opening of the rectifier 2, and the solvent vapor flows into the solvent recuperator 3 from the lower opening of the rectifier 2.

[0109] As Figure 10 As shown, the specific structure of a dual-feed mixed working fluid reverse electrodialysis low-grade heat energy power generation system provided according to the tenth embodiment of the present invention is elucidated. The tenth embodiment is a variant embodiment of the fourth embodiment. Specifically, different from the fourth embodiment, the boiling point of the regulator adopted in the tenth embodiment is higher than that of the solvent. Therefore, in the tenth embodiment, the regulator vapor flows into the regulator recuperator 9 of the operating condition adjustment module from the upper opening of the rectifier 2, and the solvent vapor flows into the solvent recuperator 3 from the lower opening of the rectifier 2.

[0110] As Figure 11 As shown, the specific structure of a dual-feed mixed working fluid reverse electrodialysis low-grade heat energy power generation system provided according to the eleventh embodiment of the present invention is elucidated. The eleventh embodiment is a variant embodiment of the fifth embodiment. Specifically, different from the fifth embodiment, the boiling point of the regulator adopted in the eleventh embodiment is higher than that of the solvent. Therefore, in the eleventh embodiment, the regulator vapor flows into the regulator recuperator 9 of the operating condition adjustment module from the upper opening of the rectifier 2, and the solvent vapor flows into the solvent recuperator 3 from the lower opening of the rectifier 2.

[0111] As Figure 12 As shown, the specific structure of a dual-feed mixed working fluid reverse electrodialysis low-grade heat energy power generation system provided according to the twelfth embodiment of the present invention is elucidated. The twelfth embodiment is a variant embodiment of the sixth embodiment. Specifically, different from the sixth embodiment, the boiling point of the regulator adopted in the twelfth embodiment is higher than that of the solvent. Therefore, in the twelfth embodiment, the regulator vapor flows into the regulator recuperator 9 of the operating condition adjustment module from the upper opening of the rectifier 2, and the solvent vapor flows into the solvent recuperator 3 from the lower opening of the rectifier 2.

[0112] It should be understood that the hybrid working fluid reverse electrodialysis low-grade heat energy power generation system with double feed inlets of the present invention is a cyclic regenerative power generation system. Utilizing low-grade heat energy, the hybrid working fluid can be decomposed into dilute solution and concentrated solution and enter the concentration difference power generation module for power generation. After the dilute solution and concentrated solution are mixed after the power generation process, they can be regenerated again in the heat generation module for the next power generation process. Therefore, the hybrid working fluid reverse electrodialysis low-grade heat energy power generation system with double feed inlets of the present invention can utilize low-grade waste heat for cyclic regenerative power generation, realizing the efficient recovery and utilization of low-grade waste heat.

[0113] It can also be understood that the hybrid working fluid reverse electrodialysis low-grade heat energy power generation system with double feed inlets uses a hybrid working fluid. No other harmful substances are generated during the power generation process, and there is no pollution to the environment. Therefore, it provides an environmentally friendly power generation system. Moreover, by using the hybrid working fluid for cyclic power generation, resource waste is avoided, and the cyclic recovery and utilization of low-grade waste heat can be realized.

[0114] Generally speaking, the hybrid working fluid reverse electrodialysis low-grade heat energy power generation system with double feed inlets of the present invention uses the reverse electrodialysis technology to convert low-grade waste heat into chemical potential energy, and uses the concentration difference between salt solutions to convert the chemical potential energy into electrical energy, realizing the efficient recovery and utilization of low-grade waste heat, which is beneficial to improving the overall utilization efficiency of waste heat resources. Moreover, the hybrid working fluid reverse electrodialysis low-grade heat energy power generation system with double feed inlets of the present invention uses a liquid distribution pipeline to lead the dilute and concentrated solutions to different feed inlets of the generator 1 respectively, reducing or eliminating the dissipation loss generated during the solution mixing process. In addition, the hybrid working fluid reverse electrodialysis low-grade heat energy power generation system with double feed inlets of the present invention also introduces a solvent and a regulator. A solution with low boiling point and low latent heat of vaporization is used as the solvent, which is beneficial to reducing the energy consumption and vacuum degree of the heat generation module; at the same time, a regulator is used to adjust the conductivity of the solution, which is beneficial to increasing the conductivity of the salt solution, thereby reducing the internal resistance loss and giving full play to the complementary advantages of the hybrid working fluid; the structure of the whole system is also optimized to ensure simple structure, reliable operation, adjustable parameters and good heat regeneration effect. In addition, the hybrid working fluid reverse electrodialysis low-grade heat energy power generation system of the present invention has a simple system structure and no moving parts. Its core components such as the ion exchange membrane 16a and the generator 1 have mature applications in the electrodialysis industry and the distillation separation industry. Therefore, this technology is more conducive to productization and actual industrial production.

[0115] The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0116] The above embodiments merely represent the preferred embodiments of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all fall within the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims.

Claims

1. A hybrid working fluid reverse electrodialysis low-grade heat energy power generation system with double feed inlets, characterized in that, it includes a heat generation module, a working condition adjustment module connected to the heat generation module, and a concentration difference power generation module connected to the working condition adjustment module. The heat generation module includes a generator and a rectifier connected to the generator. The working condition adjustment module includes a solvent condenser, a dilute solution mixer, a dilute solution pump, and a temperature equalizer arranged in sequence, and also includes a regulator diverter, a regulator condenser, a concentrated solution mixer, a concentrated solution pump arranged in sequence, and a dilute solution throttle valve and a concentrated solution throttle valve connected to different outlets of the concentration difference power generation module; wherein, the dilute solution and the concentrated solution that complete the power generation process in the concentration difference power generation module flow into the generator of the heat generation module through the dilute solution regulating valve and the concentrated solution regulating valve of the working condition adjustment module respectively. The generator is a double-feed inlet generator. The dilute solution and the concentrated solution that complete the power generation process carry out a regeneration process in the generator. The generator converts low-grade heat energy into chemical potential energy to separate the dilute solution and the concentrated solution that complete the power generation process, generating a regulator and a solvent vapor mixture and an initial concentrated solution. The regulator and the solvent vapor mixture flow into the rectifier for rectification, and the regulator vapor and the solvent vapor are output respectively and flow into the working condition adjustment module. Thus, the heat generation module completes the regeneration process; the solvent vapor flows into the solvent condenser of the working condition adjustment module for condensation and temperature reduction to form a solvent liquid. The solvent liquid flows into the dilute solution mixer and mixes with one or more of the regulator liquid, the initial concentrated solution, the dilute solution that completes the power generation process, and the concentrated solution that completes the power generation process flowing into the dilute solution mixer to carry out a conductivity adjustment process and a concentration adjustment process to form a dilute solution. The dilute solution flows through the dilute solution pump and the temperature equalizer in sequence to carry out a pressure adjustment process and a temperature adjustment process respectively, and then flows into the concentration difference power generation module; the regulator vapor flows into the regulator diverter of the working condition adjustment module for diversion. One part flows into the dilute solution mixer or the heat generation module, and the other part flows into the regulator condenser for condensation and temperature reduction. After forming a regulator liquid, it flows into the concentrated solution mixer; all or part of the initial concentrated solution flows into the concentrated solution mixer to mix with the regulator liquid, and after carrying out a conductivity adjustment process and a concentration adjustment process, a concentrated solution is formed; or a part of the initial concentrated solution flows into the dilute solution mixer, and the other part flows into the concentrated solution mixer to mix with the regulator liquid, and after carrying out a conductivity adjustment process and a concentration adjustment process, a concentrated solution is formed. The concentrated solution passes through the concentrated solution pump and the temperature equalizer in sequence to carry out a pressure adjustment process and a temperature adjustment process respectively, and then flows into the concentration difference power generation module. Thus, the working condition adjustment module completes the working condition adjustment process; After the dilute solution and the concentrated solution flow into the concentration difference power generation module, the concentration difference power generation module performs reverse electrodialysis power generation based on the salt concentration difference between the dilute solution and the concentrated solution to convert chemical potential energy into electrical energy. At this point, the concentration difference power generation module completes the power generation process.

2. The mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with dual feed inlets according to claim 1, It is characterized in that The operating condition adjustment module also includes a solvent regenerator connected to the rectifier and the solvent condenser, a regulator regenerator connected to the rectifier, the regulator diverter and the first feed port of the generator, and a concentrated solution regenerator connected to the second feed port of the generator, wherein the solvent vapor flows into the solvent condenser after being reheated and cooled by the solvent regenerator, wherein the regulator vapor flows into the regulator diverter after being reheated and cooled by the regulator regenerator, wherein the initial concentrated solution flows into the concentrated solution mixer after being reheated and cooled by the concentrated solution regenerator, wherein the dilute solution that completes the power generation process of the concentration difference power generation module is fully or partially reheated and heated in turn by the solvent regenerator, the rectifier and the regulator regenerator, and then flows into the generator through the first feed port, wherein the concentrated solution that completes the power generation process of the concentration difference power generation module is fully or partially reheated and heated in the concentrated solution regenerator, and then flows into the generator through the second feed port.

3. The mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with dual feed inlets according to claim 2, It is characterized in that The operating condition adjustment module also includes a dilute solution diverter connected to the dilute solution throttle valve, the dilute solution mixer and the solvent regenerator, wherein the dilute solution that has completed the power generation process after throttling and reducing the pressure by the dilute solution throttle valve flows into the dilute solution diverter and after diversion, a part of it flows into the dilute solution mixer, and the other part of it flows into the generator through the first feed port after being reheated and heated in turn by the solvent regenerator, the distillation device and the regulator regenerator.

4. The mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with dual feed inlets according to claim 2, It is characterized in that The operating condition adjustment module also includes a concentrated solution diverter connected to the dilute solution mixer, the concentrated solution mixer and the concentrated solution regenerator, wherein the initial concentrated solution after heat recovery in the concentrated solution regenerator flows into the concentrated solution diverter, a part of which flows into the dilute solution mixer, and the other part flows into the concentrated solution mixer.

5. The mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with dual feed inlets according to claim 2, It is characterized in that The working condition adjustment module further includes a concentrated solution diverter connected to the concentrated solution throttle valve, the dilute solution mixer, and the concentrated solution regenerator. The concentrated solution that has completed the power generation process in the concentrated difference power generation module flows into the concentrated solution diverter through the concentrated solution throttle valve. A part of it flows into the dilute solution mixer, and the other part flows into the concentrated solution regenerator for heat regeneration and temperature increase, and then flows into the generator through the second feed port.

6. The hybrid working fluid reverse electrodialysis low-grade heat energy power generation system with a dual feed port according to claim 3, characterized in that the working condition adjustment module further includes a regulator mixer connected to the dilute solution diverter, the regulator diverter, and the solvent regenerator. A part of the dilute solution that has completed the power generation process output by the dilute solution diverter and a part of the regulator steam output by the regulator diverter flow into the regulator mixer for mixing, and then sequentially pass through the solvent regenerator, the rectifier, and the regulator regenerator for heat regeneration and temperature increase, and then flow into the generator through the first feed port.

7. The hybrid working fluid reverse electrodialysis low-grade heat energy power generation system with a dual feed port according to claim 4, characterized in that the working condition adjustment module further includes a regulator mixer connected to the regulator diverter, the dilute solution throttle valve, and the solvent regenerator. A part of the regulator steam diverted by the regulator diverter flows into the regulator mixer, and after mixing with the dilute solution that has completed the power generation process flowing in through the dilute solution throttle valve, it sequentially passes through the solvent regenerator, the rectifier, and the regulator regenerator for heat regeneration and temperature increase, and then flows into the generator through the first feed port.

8. The hybrid working fluid reverse electrodialysis low-grade heat energy power generation system with a dual feed port according to claim 5, characterized in that the working condition adjustment module further includes a regulator mixer connected to the regulator diverter, the dilute solution throttle valve, and the solvent regenerator. A part of the regulator steam diverted by the regulator diverter flows into the regulator mixer, and after mixing with the dilute solution that has completed the power generation process flowing in through the dilute solution throttle valve, it sequentially passes through the solvent regenerator, the rectifier, and the regulator regenerator for heat regeneration and temperature increase, and then flows into the generator through the first feed port.

9. The hybrid working fluid reverse electrodialysis low-grade heat energy power generation system with a dual feed port according to any one of claims 1 to 8, characterized in that the working condition adjustment module further includes a dilute solution storage tank provided between the dilute solution mixer and the dilute solution pump, and a concentrated solution storage tank provided between the concentrated solution mixer and the concentrated solution pump. The dilute solution storage tank is used to adjust the flow rate of the dilute solution, and the concentrated solution storage tank is used to adjust the flow rate of the concentrated solution.

10. The hybrid working fluid reverse electrodialysis low-grade heat energy power generation system with a dual feed port according to any one of claims 1 to 8, characterized in that The described hybrid working fluid reverse electrodialysis low-grade heat energy power generation system with double feed inlets generates electricity using a hybrid working fluid. The hybrid working fluid includes a solute, a regulator, and a solvent. The solute consists of one or more pairs of anions and cations. The cations include lithium ions, sodium ions, magnesium ions, potassium ions, calcium ions, manganese ions, zinc ions, silver ions, iron ions, ferrous ions, aluminum ions, barium ions, copper ions, rubidium ions, cesium ions, strontium ions, hydrogen ions, ammonium ions; The anions include fluoride ions, chloride ions, bromide ions, iodide ions, carbonate ions, bicarbonate ions, sulfate ions, bisulfate ions, sulfite ions, bisulfite ions, cobaltate ions, silver nitrate ions, hypochlorite ions, perchlorate ions, manganate ions, oxalate ions, acetate ions, hydrocyanate ions, formate ions, phosphate ions, phosphite ions, benzoate ions, sulfide ions, chromate ions; Or the solute consists of one or more liquids, and the liquids include water, ethanol, methanol, gasoline, diesel, kerosene, acetonitrile, ether, acetone, isopropanol, hexafluoroisopropanol, trifluoroethanol, trifluoroacetic acid, tetrahydrofuran, dimethylformamide, dimethylacetamide; The regulator consists of one or more of water, formamide, trifluoroacetic acid, DMSO, acetonitrile, DMF, hexamethylphosphoramide, methanol, ethanol, acetic acid, isopropanol, pyridine, tetramethylethylenediamine, acetone, triethylamine, n-butanol, dioxane, tetrahydrofuran, methyl formate, tributylamine, methyl ethyl ketone, ethyl acetate, chloroform, trioctylamine, dimethyl carbonate, ether, isopropyl ether, n-butyl ether, trichloroethylene, diphenyl ether, dichloromethane, dichloroethane, toluene, carbon tetrachloride, carbon disulfide, cyclohexane, hexane, kerosene; The solvent consists of one or more of water, formamide, trifluoroacetic acid, DMSO, acetonitrile, DMF, hexamethylphosphoramide, methanol, ethanol, acetic acid, isopropanol, pyridine, tetramethylethylenediamine, acetone, triethylamine, n-butanol, dioxane, tetrahydrofuran, methyl formate, tributylamine, methyl ethyl ketone, ethyl acetate, chloroform, trioctylamine, dimethyl carbonate, ether, isopropyl ether, n-butyl ether, trichloroethylene, diphenyl ether, dichloromethane, dichloroethane, toluene, carbon tetrachloride, carbon disulfide, cyclohexane, hexane, kerosene; 11. The hybrid working fluid reverse electrodialysis low-grade heat energy power generation system with double feed inlets according to any one of claims 1 to 8, characterized in that, the concentration difference power generation module includes a reverse electrodialysis cell stack and an external circuit electrically connected to the reverse electrodialysis cell stack. The reverse electrodialysis cell stack includes an ion exchange membrane and an electrode system. The ion exchange membrane is used to enable the dilute solution and the concentrated solution output by the working condition adjustment module to flow and mass transfer simultaneously, so as to form a directional ion flow on both sides. The electrode system is used to convert the directional ion flow into an electron flow and output electrical energy through the external circuit.

12. The hybrid working fluid reverse electrodialysis low-grade heat energy power generation system with double feed inlets according to claim 11, characterized in that, The ion exchange membrane described above includes one or more cation exchange membranes and one or more anion exchange membranes, and the cation exchange membranes and the anion exchange membranes are arranged alternately.

13. The dual-feed mixed working fluid reverse electrodialysis low-grade heat energy power generation system according to claim 11, characterized in that, the reverse electrodialysis cell stack adopts any one of the arrangement forms of a single unit, multiple units in series, multiple units in parallel, or a hybrid of multiple units in series and parallel. The electrode system adopts active electrodes or inert electrodes, including any one of lithium electrodes, carbon electrodes, carbon rod electrodes, platinum electrodes, titanium electrodes, and copper electrodes; the electrode solution is a separate redox working fluid pair or the dilute solution and the concentrated solution.

14. The dual-feed mixed working fluid reverse electrodialysis low-grade heat energy power generation system according to any one of claims 1 to 8, characterized in that, the generator has an upper outlet and a lower outlet. The regulator and the solvent vapor mixture flow into the rectifier through the upper outlet of the generator, and the concentrated solution flows into the working condition adjustment module through the lower outlet of the generator.

15. The dual-feed mixed working fluid reverse electrodialysis low-grade heat energy power generation system according to claim 14, characterized in that, the rectifier has an upper port and a lower port. The regulator vapor flows into the working condition adjustment module through the lower port of the rectifier, and the solvent vapor flows into the working condition adjustment module through the upper port of the rectifier.

16. The dual-feed mixed working fluid reverse electrodialysis low-grade heat energy power generation system according to claim 14, characterized in that, the rectifier has an upper port and a lower port. The regulator vapor flows into the working condition adjustment module through the upper port of the rectifier, and the solvent vapor flows into the working condition adjustment module through the lower port of the rectifier.

17. The dual-feed mixed working fluid reverse electrodialysis low-grade heat energy power generation system according to any one of claims 1 to 8, characterized in that, the temperature equalizer is a two-stream heat exchange type temperature equalizer or a three-stream heat exchange type temperature equalizer.

18. The dual-feed mixed working fluid reverse electrodialysis low-grade heat energy power generation system according to any one of claims 1 to 8, characterized in that, the dilute solution pump and the concentrated solution pump are any one of volumetric, dynamic, and diaphragm types, and adopt any one of the arrangement forms of a single unit, multiple units in series, multiple units in parallel, or a hybrid of multiple units in series and parallel.

19. The dual-feed mixed working fluid reverse electrodialysis low-grade heat energy power generation system according to any one of claims 1 to 8, characterized in that, the solvent condenser and the regulator condenser adopt any one of the heat exchange methods of natural air convection heat transfer, forced air convection heat transfer, mixed air convection heat transfer, radiation heat transfer, natural liquid convection heat transfer, and forced liquid convection heat transfer, and adopt any one of the arrangement forms of a single unit, multiple units in series, multiple units in parallel, or a hybrid of multiple units in series and parallel.

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