A mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet

Abstract

The invention relates to a mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet, comprising a heat generation module, a working condition adjustment module and a concentration difference power generation module. The heat generation module is driven by low-grade thermal energy and is used to convert low-grade thermal energy into chemical potential energy to realize the regeneration process of an intermediate concentration solution; the working condition adjustment module performs conductivity adjustment, temperature adjustment, pressure adjustment and flow adjustment processes on a dilute solution and a concentrated solution according to the working condition; the concentration difference power generation module performs a reverse electrodialysis power generation process using the salt concentration difference between the dilute solution and the concentrated solution, and outputs the intermediate concentration solution to complete the power generation cycle process. The system adopts 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, a regulator is introduced to adjust the solution conductivity, reduce the internal resistance loss, and give full play to the complementary advantages of the mixed working fluid. The entire system has a simple structure, reliable operation, and adjustable parameters.

Description

Technical Field

[0001] The invention relates to the field of new energy technology, and in particular to a mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet. Background Art

[0002] Energy is the cornerstone of social and economic development. With the rapid development of society, human demand for primary energy is increasing day by day. However, with the over-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, since the combustion process of primary energy is accompanied by the generation of a large amount of pollutants and carbon dioxide, environmental problems are becoming increasingly prominent. According to statistics, if the existing energy use mode cannot be changed, the earth's temperature will rise by 6℃ by the end of the 21st century. Therefore, it is urgent to improve the efficiency of existing energy utilization technology and reduce primary energy consumption.

[0003] Waste heat is the heat lost to the environment in the form of thermal energy during industrial production. Waste heat resources are very abundant and widely distributed in industries such as petroleum, steel, coal, and building materials. It accounts for about one-third of the energy input of industrial production and is regarded as the fifth largest conventional energy after coal, oil, natural gas, and hydropower. Since this part of energy is not effectively utilized in the production process, it causes a great loss of energy. Therefore, the efficient use of waste heat can significantly improve the utilization efficiency of primary energy. In view of the fact that most industrial production uses electricity as the main driving energy, and the transmission and matching of electricity are relatively easy, it is more suitable for the actual industrial situation to convert waste heat into electricity.

[0004] Existing waste heat power generation technologies include: steam turbine power generation, organic Rankine cycle power generation, full-flow turbine power generation, screw expander power generation and reverse electrodialysis heat engine power generation. Except for reverse electrodialysis heat engine power generation technology, other power generation technologies are only applicable to medium-high-grade and high-grade waste heat, and efficiency issues, working fluid selection issues, turbine manufacturing issues and economic issues have always plagued the development and application of the above technologies, causing most technologies to remain at the experimental and theoretical level. What is more noteworthy is that low-grade waste heat accounts for about 42% of the total waste heat. The efficient use of low-grade waste heat can 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 thermal energy in waste heat into chemical potential energy between salt solutions, and uses reverse electrodialysis technology to convert the chemical potential energy into electrical energy, thereby realizing the use of waste heat for power generation. 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 with the existing reverse electrodialysis heat engine system: First, 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 lot of energy; second, the boiling point of water at normal pressure is high. When using low-grade waste heat for power generation, the system vacuum degree is high; third, when other liquids such as ethanol are used as solvents, the conductivity of the salt solution is low, the internal resistance of the battery module is large, and the internal resistance loss increases; fourth, the internal heat recovery effect of the system is poor, and the system The loss is huge. Summary of the invention

[0006] Based on this, one object of the present invention is to provide a mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet. The system introduces a solvent with a low boiling point and a low 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 and reduce the internal resistance loss. In addition, the system structure is optimized to ensure a simple structure, reliable operation, adjustable parameters and good heat recovery effect.

[0007] A mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet comprises 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 contains an intermediate concentration solution and is configured to be driven by low-grade thermal energy, and is used to convert low-grade thermal energy into chemical potential energy generated by the concentration difference between salt solutions, so as to separate the intermediate concentration solution into a regulator, a solvent, and an initial concentrated solution. The working condition adjustment module is used to adjust the conductivity, temperature, pressure, and flow rate of the regulator, the solvent, and the initial concentrated solution, respectively, so as to output a dilute solution and a concentrated solution to the concentration difference power generation module. The concentration difference power generation module is used to perform 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 of the concentration difference power generation module that have completed the power generation process flow into the working condition adjustment module to form the intermediate concentration solution, and the intermediate concentration solution flows into the heat generation module for a regeneration process.

[0008] In one embodiment of the present invention, the heat generation module includes a generator and a rectifier connected to the generator, the operating condition adjustment module includes a solvent condenser, a dilute solution mixer and a dilute solution pump arranged in sequence, the operating condition adjustment module also includes a regulator condenser, a regulator splitter, a concentrated solution mixer and a concentrated solution pump arranged in sequence, the generator is used to convert low-grade thermal energy into chemical potential energy, so that the intermediate concentration solution is separated into a mixture of regulator and solvent and the initial concentrated solution, wherein the initial concentrated solution flows in whole or in part into the concentrated solution mixer, wherein the mixture of regulator and solvent flows into the rectifier for distillation, and regulator vapor and solvent vapor are output respectively, wherein the regulator vapor passes through the regulator condenser After condensation and cooling, a regulator liquid is formed, and the regulator liquid is diverted by the regulator diverter, and a part of it flows into the concentrated solution mixer, and is mixed with the initial concentrated solution to form the concentrated solution, and the concentrated solution flows into the concentration difference power generation module through the concentrated solution pump, and the other part of the regulator liquid flows into the dilute solution mixer or the heat generation module; wherein the solvent vapor flows into the solvent condenser for condensation and cooling to form a solvent liquid, and the solvent liquid flows into the dilute solution mixer for conductivity and concentration adjustment, and forms the dilute solution with any one or more of the regulator liquid, the intermediate concentration solution and the initial concentrated solution, and the dilute solution flows into the dilute solution pump for pressure adjustment and then flows into the concentration difference power generation module.

[0009] In one embodiment of the present invention, the operating condition regulation module also includes a concentrated solution regenerator connected to the generator, a regulator regenerator connected to the rectifier, the regulator condenser and the concentrated solution regenerator, a solvent regenerator connected to the rectifier and the solvent condenser, and a thermostat connected to the dilute solution pump, the concentrated solution pump and the concentration difference power generation module, wherein the concentrated solution regenerator is used to perform heat recovery treatment on the initial concentrated solution to reduce the temperature of the initial concentrated solution, the regulator regenerator is used to perform heat recovery treatment on the regulator vapor to reduce the temperature of the regulator vapor, the solvent regenerator is used to perform heat recovery treatment on the solvent vapor to reduce the temperature of the solvent vapor, and the thermostat is used to regulate the temperature of the dilute solution and the concentrated solution.

[0010] In one embodiment of the present invention, the thermostat is a two-stream heat exchange type thermostat or a three-stream heat exchange type thermostat.

[0011] In one embodiment of the present invention, the operating condition adjustment module also includes a solution mixer connected to the concentration difference power generation module and a throttle valve connected to the solution mixer. The dilute solution and the concentrated solution that complete the power generation process of the concentration difference power generation module flow into the solution mixer to form the intermediate concentration solution. After the intermediate concentration solution is throttled and reduced in pressure by the throttle valve, all of the solution is successively heat-recovered by the solvent regenerator, the rectifier, the regulator regenerator and the concentrated solution regenerator before flowing into the heat generation module, or a part of the solution flows into the dilute solution mixer, and the other part of the solution is successively heat-recovered by the solvent regenerator, the rectifier, the regulator regenerator and the concentrated solution regenerator before flowing into the heat generation module.

[0012] In one embodiment of the present invention, the operating condition adjustment module also includes an intermediate concentration solution diverter connected to the throttle valve and the dilute solution mixer, wherein the intermediate concentration solution output by the throttle valve is diverted by the intermediate concentration solution diverter, and a part of it flows into the dilute solution mixer, and the other part flows into the heat generation module after being heat-recovered in sequence by the solvent regenerator, the distillation device, the regulator regenerator and the concentrated solution regenerator.

[0013] In one embodiment of the present invention, the operating condition adjustment module also includes a concentrated solution diverter connected to the concentrated solution regenerator, the concentrated solution mixer and the dilute solution mixer, and the concentrated solution diverter is used to divert the initial concentrated solution after heat recovery treatment by the concentrated solution regenerator, a part of the initial concentrated solution flows into the concentrated solution mixer, and the other part flows into the dilute solution mixer.

[0014] In one embodiment of the present invention, the operating condition adjustment module also includes a regulator mixer connected to the intermediate concentration solution diverter, the regulator diverter and the solvent regenerator, wherein a portion of the regulator liquid diverted by the regulator diverter and a portion of the intermediate concentration solution diverted by the intermediate concentration solution diverter flow into the regulator mixer for mixing, and then flow through the solvent regenerator, the distillation device, the regulator regenerator and the concentrated solution regenerator in sequence for heat recovery treatment before flowing into the heat generation module.

[0015] In one embodiment of the present invention, the flow splitting ratio adjustment range of the regulator splitter, the intermediate concentration solution splitter and the concentrated solution splitter is 0% to 100%.

[0016] In one embodiment of the present invention, the operating condition adjustment module also includes a dilute solution storage tank and a concentrated solution storage tank. The dilute solution storage tank is arranged between the dilute solution mixer and the dilute solution pump, and is used to adjust the flow rate of the dilute solution output by the dilute solution mixer; the concentrated solution storage tank is arranged between the concentrated solution mixer and the concentrated solution pump, and is used to adjust the flow rate of the concentrated solution output by the concentrated solution mixer.

[0017] In one embodiment of the present invention, the intermediate concentration solution includes a solute, a regulator and a dissolving agent, 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, and 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, and chromate ions. ; 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, tetrafluorofuran, dimethylformamide, and dimethylacetamide; the polarity of the regulator is higher than the polarity of the solvent, and the regulator or 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.

[0018] In one 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 make the dilute solution and the concentrated solution output by the operating condition adjustment module flow and transfer mass at the same time 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 to the outside through the external circuit.

[0019] In one embodiment of the present invention, the ion exchange membrane comprises 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.

[0020] In one embodiment of the present invention, the reverse electrodialysis cell stack adopts any one of the arrangements of a single unit, multiple units in series, multiple units in parallel, or a mixture of multiple units in series and parallel; the electrode system 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 liquid is a separate redox working fluid pair or the dilute solution and the concentrated solution.

[0021] In one embodiment of the present invention, the generator has an upper outlet and a lower outlet, the 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 operating condition adjustment module through the lower outlet of the generator.

[0022] In one embodiment of the present invention, the rectifier has an upper port and a lower port, the regulator vapor flows into the operating condition adjustment module through the lower port of the rectifier, and the solvent vapor flows into the operating condition adjustment module through the upper port of the rectifier.

[0023] In one embodiment of the present invention, the rectifier has an upper port and a lower port, the regulator vapor flows into the operating condition adjustment module through the upper port of the rectifier, and the solvent vapor flows into the operating condition adjustment module through the lower port of the rectifier.

[0024] In one embodiment of the present invention, the dilute solution pump and the concentrated solution pump are any one of volumetric, dynamic and diaphragm types, and are arranged in any form of a single unit, multiple units in series, multiple units in parallel or a mixture of multiple units in series and parallel.

[0025] In one embodiment of the present invention, the solvent condenser and the regulator condenser use any one of air natural convection heat exchange, air forced convection heat exchange, air mixed convection heat exchange, radiation heat exchange, liquid natural convection heat exchange and liquid forced convection heat exchange for heat exchange, and use any one of the arrangements of a single unit, multiple units in series, multiple units in parallel, or a mixture of multiple units in series and parallel.

[0026] The beneficial effects of the present invention are as follows: the mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed port of the present invention utilizes reverse electrodialysis technology to convert low-grade waste heat into chemical potential energy, and utilizes the concentration difference between salt solutions to convert chemical potential energy into electrical energy, thereby realizing efficient recovery and utilization of low-grade waste heat, which is beneficial to improving the overall utilization efficiency of waste heat resources. Moreover, the mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed port of the present invention introduces a solubilizer and a regulator, and uses a solution with a low boiling point and low latent heat of vaporization as a solubilizer, which is beneficial to reducing the energy consumption and vacuum degree of the heat generation module; at the same time, the regulator is used to adjust the conductivity of the solution, which is beneficial to improving the conductivity of the salt solution, thereby reducing the internal resistance loss and giving full play to the complementary advantages of the mixed working fluid; in addition, the structure of the entire system is optimized to ensure a simple structure, reliable operation, adjustable parameters and good heat recovery effect. In addition, the single-feed mixed working fluid reverse electrodialysis low-grade thermal energy power generation system of the present invention has a simple system structure and no moving parts, and its core components such as ion exchange membranes and generators have mature applications in the electrodialysis industry and distillation separation industry, so this technology is easier to commercialize and put into actual industrial production.

[0027] Further objects and advantages of the present invention will be fully apparent from an understanding of the following description and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A schematic structural diagram of a mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet provided in the first embodiment of the present invention;

[0029] Figure 2 A schematic structural diagram of a mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet provided in a second embodiment of the present invention;

[0030] Figure 3 A schematic structural diagram of a mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet provided in a third embodiment of the present invention;

[0031] Figure 4 A schematic structural diagram of a mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet provided in a fourth embodiment of the present invention;

[0032] Figure 5 A schematic structural diagram of a mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet provided in a fifth embodiment of the present invention;

[0033] Figure 6 A schematic structural diagram of a mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet provided in a sixth embodiment of the present invention;

[0034] Figure 7 A schematic structural diagram of a mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet provided in the seventh embodiment of the present invention;

[0035] Figure 8 A schematic structural diagram of a mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet provided for the eighth embodiment of the present invention.

[0036] Description of the accompanying 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, regulator regenerator 9, regulator condenser 10, regulator splitter 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, solution mixer 18, throttle valve 19, intermediate concentration solution splitter 20, concentrated solution splitter 21, regulator mixer 22. In the accompanying drawings, the arrow direction is the solution flow direction. DETAILED DESCRIPTION

[0037] 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 those skilled in the art can think of other obvious variations. The basic principles of the present invention defined in the following description can be applied to other embodiments, deformation schemes, improved schemes, equivalent schemes, and other technical solutions that do not deviate from the spirit and scope of the present invention.

[0038] Those skilled in the art should understand that, in the disclosure of the present invention, the terms "vertical", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, which 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 understood as limiting the present invention.

[0039] It is to be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the element may be multiple, and the term "one" should not be understood as a limitation on the quantity.

[0040] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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 mutual communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0041] In the field of reverse electrodialysis heat engine technology, the factors that restrict the efficiency of reverse electrodialysis heat engine mainly include two points. First, the regeneration unit consumes a lot of energy. Specifically, due to the large latent heat of vaporization of the solute, the "thermal-chemical potential energy" conversion efficiency is restricted. Second, when using a low latent heat of vaporization solute, the solute conductivity is usually poor, 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, resulting in a low overall utilization efficiency of waste heat resources.

[0042] To solve the above problems, the present application provides a low-grade thermal energy power generation system for mixed working fluid reverse electrodialysis with a single feed inlet. The system uses an alternative solvent with a low boiling point and latent heat of vaporization, which can 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, which is conducive to reducing the internal resistance loss. In addition, the overall structure of the system is optimized to ensure a simple structure, reliable operation, adjustable parameters and good heat recovery effect.

[0043] like Figure 1As shown, the specific structure of a mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet provided according to the first embodiment of the present invention is explained. Specifically, the mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet 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 contains an intermediate concentration solution and is configured to be driven by low-grade thermal energy, and is used to convert low-grade thermal energy into chemical potential energy generated by the concentration difference between salt solutions, so as to separate the intermediate concentration solution into a regulator, a solvent and an initial concentrated solution. The working condition adjustment module is used to adjust the conductivity, temperature, pressure and flow rate of the regulator, the solvent and the initial concentrated solution, respectively, so as to output a dilute solution and a concentrated solution to the concentration difference power generation module. The concentration difference power generation module is used to perform 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 of the concentration difference power generation module that complete the power generation process flow into the working condition adjustment module to form the intermediate concentration solution, and the intermediate concentration solution flows into the heat generation module for a regeneration process.

[0044] It can be understood that the principle of power generation by the mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet is: using the heat generation module to convert low-grade thermal energy into chemical potential energy generated by the concentration difference between salt solutions, and using reverse electrodialysis technology to convert the chemical potential energy into electrical energy by utilizing the salt concentration difference between the dilute solution and the concentrated solution, thereby achieving efficient recovery and utilization of low-grade waste heat, which is beneficial to improving the overall utilization efficiency of waste heat resources.

[0045] In this embodiment, the heat generating module includes a generator 1 and a distillation device 2 connected to the generator 1, the operating condition adjustment module includes a solvent regenerator 3, a solvent condenser 4, a dilute solution mixer 5 and a dilute solution pump 7 arranged in sequence, the operating condition adjustment module also includes a regulator regenerator 9, a regulator condenser 10, and a regulator diverter 11 arranged in sequence, the operating condition adjustment module also includes a concentrated solution regenerator 15, a concentrated solution mixer 12 and a concentrated solution pump 14 arranged in sequence, the operating condition adjustment module also includes a solution mixer 18, a throttle valve 19 connected to the solution mixer 18, an intermediate concentration solution diverter 20 connected to the throttle valve 19, the dilute solution mixer 5, and the solvent regenerator 3, and a thermostat 8 connected to the dilute solution pump 7 and the concentrated solution pump 14.

[0046] It is worth mentioning that the generator 1 is used to convert low-grade thermal energy into chemical potential energy so that the intermediate concentration solution is separated into a mixture of a regulator and a solvent and the initial concentrated solution, the rectifier 2 is used to rectify the mixture of the regulator and the solvent to output regulator vapor and solvent vapor respectively, the solvent regenerator 3 is used to reheat the solvent vapor to reduce the temperature of the solvent vapor, the solvent condenser 4 is used to condense and cool the cooled solvent vapor to form a solvent liquid, the dilute solution mixer 5 is used to condense the solvent liquid, the intermediate concentration solution and the solvent vapor obtained by mixing the intermediate concentration solution with the dilute solution. A portion of the intermediate concentration solution output by the intermediate concentration solution splitter 20 and a portion of the regulator liquid output by the regulator splitter 11 are adjusted in conductivity and concentration to form the dilute solution, wherein the dilute solution pump 7 is used to adjust the pressure of the dilute solution; wherein the regulator regenerator 9 is used to perform heat recovery treatment on the regulator steam to reduce the temperature of the regulator steam, wherein the regulator condenser 10 is used to condense and cool the cooled regulator steam to form a regulator liquid, and the regulator splitter 11 is used to split the regulator liquid so that the regulator liquid is output in two parts, A portion of the regulator liquid enters the concentrated solution mixer 12, and another portion of the regulator liquid enters the dilute solution mixer 5; wherein the concentrated solution regenerator 15 is used to perform heat recovery treatment on the initial concentrated solution to reduce the temperature of the initial concentrated solution, the concentrated solution mixer 12 is used to adjust the conductivity and concentration of the regulator liquid flowing in from the regulator diverter 11 and the initial concentrated solution to form the concentrated solution, the concentrated solution pump 14 is used to adjust the pressure of the concentrated solution, the thermostat 8 is used to adjust the temperature of the dilute solution after pressure adjustment and the concentrated solution after pressure adjustment, and the dilute solution after temperature adjustment The dilute solution and the concentrated solution flow into the concentration difference power generation module for reverse electrodialysis power generation, wherein the solution mixer 18 is used to mix the dilute solution and the concentrated solution that have completed the power generation process to form the intermediate concentration solution, the throttle valve 19 is used to throttle and reduce the pressure of the intermediate concentration solution, and the intermediate concentration solution diverter 20 diverts the intermediate concentration solution after the pressure reduction, so that a part of the intermediate concentration solution enters the dilute solution mixer 5, and the other part of the intermediate concentration solution is successively reheated and heated through the solvent regenerator 3, the distillation device 2, the regulator regenerator 9 and the concentrated solution regenerator 15 before flowing into the generator 1.

[0047] It is understandable that the generator 1 has only a single feed inlet for the intermediate concentration solution to enter, so the present invention provides a mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet.

[0048] It can also be understood that, since the mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet respectively uses the solvent regenerator 3 to perform heat recovery treatment on the solvent vapor, uses the regulator regenerator 9 to perform heat recovery treatment on the regulator vapor, uses the concentrated solution regenerator 15 to perform heat recovery treatment on the initial concentrated solution, and uses the thermostat 8 to perform heat recovery treatment on the dilute solution and the concentrated solution, the temperature adjustment processes between the solvent vapor, the regulator vapor and the initial concentrated solution can be performed independently without interfering with each other. Moreover, the mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet uses the solvent regenerator 3, the regulator regenerator 9 and the concentrated solution regenerator 15 to perform heat recovery treatment on the intermediate concentration solution, which is conducive to ensuring that the entire system has a good heat recovery effect, making the structure of the entire system more compact and simple.

[0049] In some embodiments of the present invention, the intermediate concentration solution flows from the concentration difference power generation module into the operating condition adjustment module, and can flow through one or more devices in the rectifier 2, the solvent regenerator 3, the regulator regenerator 9 and the concentrated solution regenerator 15 in any order to undergo a heat recovery process, with the temperature rising, and then flows into the heat generation module. The present invention does not impose any restrictions on this.

[0050] It is worth mentioning that the thermostat 8 is a two-stream heat exchange type thermostat or a three-stream heat exchange type thermostat. In other words, the thermostat 8 can adopt a two-stream heat exchange form, and can also introduce a third fluid to adjust the temperature of the solution.

[0051] It is also worth mentioning that the regulator splitter 11, the intermediate concentration solution splitter 20 and the concentrated solution splitter 21 can adjust the split ratio according to actual working conditions, and the adjustment range is 0% to 100%.

[0052] In addition, it is worth mentioning that the dilute solution pump 7 and the concentrated solution pump 14 are any of the volumetric, power and diaphragm types, and are arranged in a single unit, multiple units in series, multiple units in parallel or multiple units in series and parallel. In other words, the dilute solution pump 7 and the concentrated solution pump 14 can be selected from the volumetric, power and diaphragm types, and can be arranged in a single unit, multiple units in series, multiple units in parallel or multiple units in series and parallel.

[0053] In addition, the solvent condenser 4 and the regulator condenser 10 use any one of the heat exchange methods of air natural convection heat exchange, air forced convection heat exchange, air mixed convection heat exchange, radiation heat exchange, liquid natural convection heat exchange and liquid forced convection heat exchange for heat exchange, and use any one of the layout forms of a single unit, multiple units in series, multiple units in parallel, or a mixture of multiple units in series and parallel.

[0054] In other words, the solvent condenser 4 and the regulator condenser 10 can exchange heat with the outside in different ways, including natural convection heat exchange by air, forced convection heat exchange by air, mixed convection heat exchange by air, radiation heat exchange, natural convection heat exchange by liquid and forced convection heat exchange by liquid, and can be arranged in the form of a single unit, multiple units in series, multiple units in parallel, or a mixture of multiple units in series and parallel.

[0055] It is worth mentioning that when the solvent condenser 4 and the regulator condenser 10 adopt forced convection heat exchange, the cold and hot fluids can exchange heat in a co-current, counter-current and cross-current manner.

[0056] Furthermore, the operating condition adjustment module also includes a dilute solution storage tank 6 and a concentrated solution storage tank 13. The dilute solution storage tank 6 is arranged between the dilute solution mixer 5 and the dilute solution pump 7, and is used to adjust the flow rate of the dilute solution output by the dilute solution mixer 5; the concentrated solution storage tank 13 is arranged between the concentrated solution mixer 12 and the concentrated solution pump 14, and is used to adjust the flow rate of the concentrated solution output by the concentrated solution mixer 12, which is beneficial to ensure the stability of power generation of the entire system and make the power output stable.

[0057] It is worth mentioning that 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 operating condition adjustment module through the lower outlet of the generator 1.

[0058] In addition, it is 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 operating condition adjustment module through the lower port of the rectifier 2, and the solvent vapor flows into the operating condition adjustment module through the upper port of the rectifier 2.

[0059] In some embodiments of the present invention, such as in the fifth to eighth embodiments, when the boiling point of the regulator is higher than the boiling point of the solvent, the regulator vapor flows into the regulator reheater 9 of the operating condition adjustment module through the upper port of the rectifier 2, and the solvent vapor flows into the solvent reheater 3 of the operating condition adjustment module through the lower port of the rectifier 2.

[0060] 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 make the dilute solution and the concentrated solution output by the operating condition adjustment module flow and transfer mass at the same time 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 to the outside through the external circuit 17.

[0061] In particular, 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 the 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, and the present invention is not limited to this.

[0062] It is worth mentioning that the reverse electrodialysis cell stack 16 adopts any one of the arrangements of a single unit, multiple units in series, multiple units in parallel, or a mixture 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 liquid is a separate redox working fluid pair or the dilute solution and the concentrated solution.

[0063] In particular, the intermediate concentration solution of the present invention comprises a solute, the regulator and the solubilizer, wherein the solute is composed of one or more pairs of anions and cations, wherein 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, and ammonium ions; and the anions include fluoride ions, chloride ions, bromide ions, iodide ions, carbonate ions, bicarbonate ions, sulfate ions, bisulfate ions, and sulfite ions. Ion, bisulfite ion, cobaltate ion, silver nitrate ion, hypochlorite ion, perchlorate ion, manganate ion, oxalate ion, acetate ion, hydrocyanate ion, formate ion, phosphate ion, phosphite ion, benzoate ion, sulfide ion, chromate ion; or the solute is composed of one or more liquids, and the liquid includes water, ethanol, methanol, gasoline, diesel, kerosene, acetonitrile, ether, acetone, isopropanol, hexafluoroisopropanol, trifluoroethanol, trifluoroacetic acid, tetrafluorofuran, dimethylformamide, and dimethylacetamide.

[0064] 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, ethyl ether, isopropyl ether, n-butyl ether, trichloroethylene, diphenyl ether, dichloromethane, dichloroethane, toluene, carbon tetrachloride, carbon disulfide, cyclohexane, hexane, and kerosene, and the polarity of the regulator is higher than that of the solvent.

[0065] 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, ethyl ether, isopropyl ether, n-butyl ether, trichloroethylene, diphenyl ether, dichloromethane, dichloroethane, toluene, carbon tetrachloride, carbon disulfide, cyclohexane, hexane, and kerosene.

[0066] It is worth mentioning that the concentration range of the dilute solution of 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.

[0067] It should be understood that since the polarity of the regulator is higher than that of the solvent, the regulator and the solvent cannot be selected as the same solution, so the mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed port of the present invention uses a mixed working fluid for power generation. Specifically, the mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed port uses a solution with a low boiling point and low latent heat of vaporization as a solvent to reduce the energy consumption and vacuum degree of the heat generation module; at the same time, the regulator is used to adjust the conductivity of the solution to improve the conductivity of the salt solution, thereby reducing the internal resistance loss and giving full play to the complementary advantages of the mixed working fluid.

[0068] In particular, the mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet has a regeneration process, a working condition adjustment process and a power generation process. Specifically, the mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet uses the heat generation module to complete the regeneration process, uses the working condition adjustment module to complete the working condition adjustment process, the working condition adjustment process includes a temperature adjustment process, a conductivity adjustment process, a flow adjustment process, and a pressure adjustment process, and uses the concentration difference power generation module to complete the power generation process.

[0069] More specifically, the intermediate concentration solution flows from the working condition regulating module into the generator 1 for the regeneration process, and the generator 1 uses the heat of the low-grade driving heat source to separate the intermediate concentration solution to produce the regulator and solvent vapor mixture and the initial concentrated solution; the regulator and solvent vapor mixture that completes the regeneration process flows out from the upper port of the generator 1 and flows into the rectifier 2 for the distillation process to become the regulator vapor and the solvent vapor, which flow out from the lower port and the upper port of the rectifier 2 respectively and flow into the working condition regulating module; the concentrated solution that completes the regeneration process flows out from the lower port of the generator 1 and flows into the working condition regulating module; at this point, the heat generating module completes the regeneration process;

[0070] The solvent vapor flows from the heat generation module into the operating condition adjustment module, and flows through the solvent regenerator 3 and the solvent condenser 4 in sequence, undergoes a regeneration process and a condensation process, and the temperature is reduced to become the solvent liquid; the solvent liquid flows into the dilute solution mixer 5, undergoes a conductivity adjustment process and a concentration adjustment process, and is mixed with the regulator liquid and the intermediate concentration solution to become the dilute solution; the dilute solution flows through the dilute solution storage tank 6, the dilute solution pump 7 and the thermostat 8 in sequence, undergoes a flow adjustment process, a pressure adjustment process and a temperature adjustment process, and then flows into the concentration difference power generation module;

[0071] The regulator steam flows from the heat generating module into the working condition regulating module, and flows through the regulator regenerator 9 and the regulator condenser 10 in sequence, undergoes a regenerating process and a condensing process, and the temperature is reduced to become the regulator liquid; the regulator liquid flows into the regulator splitter 11 and is split, with a part of the liquid flowing into the dilute solution mixer 5 and the rest flowing into the concentrated solution mixer 12;

[0072] The concentrated solution flows from the heat generation module into the working condition adjustment module, and sequentially flows through the concentrated solution regenerator 15, the concentrated solution mixer 12, the concentrated solution storage tank 13, the concentrated solution pump 14 and the thermostat 8, undergoing a heat recovery process, a conductivity adjustment process, a flow adjustment process, a pressure adjustment process and a temperature adjustment process, and then flows into the concentration difference power generation module;

[0073] The dilute solution and the concentrated solution that have completed the power generation process flow from the concentration difference power generation module into the operating condition adjustment module, and undergo a mixing process in the solution mixer 18 to become the intermediate concentration solution; the intermediate concentration solution flows into the throttle valve 19 to undergo a throttling process, the pressure is reduced, and then flows into the intermediate concentration solution diverter 20 for diversion, a part of the liquid flows into the dilute solution mixer 5, and the rest preferably flows through the solvent regenerator 3, the rectifier 2, the regulator regenerator 9 and the concentrated solution regenerator 15 in sequence, undergoes a heat recovery process, the temperature rises, and then flows into the heat generation module; at this point, the operating condition adjustment module completes the operating condition adjustment process;

[0074] The dilute solution and the concentrated solution flow from the operating condition adjustment module into the concentration difference power generation module, and then flow into the reverse electrodialysis cell stack 16 to carry out the reverse electrodialysis power generation process; the dilute solution and the concentrated solution simultaneously carry out the flow and mass transfer process between the ion exchange membrane 16a, and the salt ions in the dilute solution and the concentrated solution pass through the ion exchange membrane 16a in a directed manner under the action of concentration potential energy, forming a directed ion flow on both sides of the ion exchange membrane 16a, and then the directed ion flow is converted into an electron flow through the electrode system 16b, and the electrical energy is output to the outside through the external circuit 17; the dilute solution and the concentrated solution that have completed the power generation process flow into the operating condition adjustment module; at this point, the concentration difference power generation module completes the power generation process.

[0075] It can be understood that in this embodiment of the present invention, the dilute solution is formed by the solvent liquid, a portion of the regulator liquid and a portion of the intermediate concentration solution, and the initial concentrated solution all flows into the concentrated solution mixer 12 to mix with another portion of the regulator liquid to form the concentrated solution.

[0076] like Figure 2 As shown, the specific structure of a mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet provided according to the second embodiment of the present invention is explained. The second embodiment is a modified embodiment of the first embodiment. Specifically, unlike the first embodiment, the operating condition adjustment module also includes a concentrated solution diverter 21 connected to the concentrated solution regenerator 15, the concentrated solution mixer 12 and the dilute solution mixer 5, and the concentrated solution diverter 21 is used to divert the initial concentrated solution after the heat recovery treatment of the concentrated solution regenerator 15, a part of the initial concentrated solution flows into the concentrated solution mixer 12, and the other part flows into the dilute solution mixer 5 to form the dilute solution with the solvent liquid and a part of the regulator liquid.

[0077] Moreover, in this embodiment, the working condition adjustment module does not include the intermediate concentration solution diverter 20. That is, in the second embodiment, the dilute solution does not include the intermediate concentration solution, and all the intermediate concentration solutions are throttled and depressurized by the throttle valve 19, and then successively reheated and heated by the solvent regenerator 3, the rectifier 2, the regulator regenerator 9 and the concentrated solution regenerator 15 before flowing into the generator 1 for the regeneration process.

[0078] 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 liquid and a part of the initial concentrated solution, and another part of the initial concentrated solution flows into the concentrated solution mixer 12 to mix with another part of the regulator liquid to form the concentrated solution. Moreover, all of the intermediate concentration solution flows into the heat generation module through the working condition adjustment module.

[0079] like Figure 3 As shown, the specific structure of a mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet provided according to the third embodiment of the present invention is explained. The third embodiment is a modified embodiment of the first embodiment. Specifically, unlike the first embodiment, the operating condition adjustment module also includes a regulator mixer 22 connected to the intermediate concentration solution diverter 20, the regulator diverter 11 and the solvent regenerator 3, wherein a portion of the regulator liquid diverted by the regulator diverter 11 and a portion of the intermediate concentration solution diverted by the intermediate concentration solution diverter 20 flow into the regulator mixer 22 for mixing, and then successively pass through the solvent regenerator 3, the distillation device 2, the regulator regenerator 9 and the concentrated solution regenerator 15 for heat recovery treatment before flowing into the heat generation module.

[0080] In a third embodiment, the dilute solution is formed by the solvent liquid and a portion of the intermediate concentration solution.

[0081] like Figure 4 As shown, the specific structure of a mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet provided according to the fourth embodiment of the present invention is explained. The fourth embodiment is a modified embodiment of the first embodiment. Specifically, unlike the first embodiment, the operating condition adjustment module also includes a concentrated solution diverter 21 connected to the concentrated solution regenerator 15, the concentrated solution mixer 12 and the dilute solution mixer 5, and the concentrated solution diverter 21 is used to divert the initial concentrated solution after the heat recovery treatment of the concentrated solution regenerator 15, and a part of the initial concentrated solution flows into the concentrated solution mixer 12, and the other part flows into the dilute solution mixer 5.

[0082] The operating condition adjustment module also includes a regulator mixer 22 connected to the intermediate concentration solution diverter 20, the regulator diverter 11 and the solvent regenerator 3, wherein a portion of the regulator liquid diverted by the regulator diverter 11 and a portion of the intermediate concentration solution diverted by the intermediate concentration solution diverter 20 flow into the regulator mixer 22 for mixing, and then successively pass through the solvent regenerator 3, the distillation device 2, the regulator regenerator 9 and the concentrated solution regenerator 15 for heat recovery treatment before flowing into the heat generation module.

[0083] That is to say, in the fourth embodiment, the dilute solution is formed by the solvent liquid, a part of the initial concentrated solution and a part of the intermediate concentration solution, and the other part of the intermediate concentration solution and a part of the regulator liquid enter the regulator mixer 22 for mixing, and then pass through the solvent regenerator 3, the distillation device 2, the regulator regenerator 9 and the concentrated solution regenerator 15 for heat recovery treatment in sequence before flowing into the heat generating module.

[0084] like Figure 5 As shown, the specific structure of a mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet provided in accordance with the fifth embodiment of the present invention is illustrated. The fifth embodiment is a modified embodiment of the first embodiment. Specifically, unlike the first embodiment, the boiling point of the regulator used in the fifth embodiment is higher than the boiling point of the solvent. Therefore, in the fifth embodiment, the regulator vapor flows from the upper port of the rectifier 2 into the regulator regenerator 9 of the operating condition adjustment module, and the solvent vapor flows from the lower port of the rectifier 2 into the solvent regenerator 3.

[0085] like Figure 6 As shown, the specific structure of a mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet provided according to the sixth embodiment of the present invention is explained. The sixth embodiment is a modified embodiment of the second embodiment. Specifically, unlike the second embodiment, the boiling point of the regulator used in the sixth embodiment is higher than the boiling point of the solvent. Therefore, in the sixth embodiment, the regulator vapor flows from the upper port of the rectifier 2 into the regulator regenerator 9 of the operating condition adjustment module, and the solvent vapor flows from the lower port of the rectifier 2 into the solvent regenerator 3.

[0086] like Figure 7 As shown, the specific structure of a mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet provided according to the seventh embodiment of the present invention is explained. The seventh embodiment is a modified embodiment of the third embodiment. Specifically, unlike the third embodiment, the boiling point of the regulator used in the seventh embodiment is higher than the boiling point of the solvent. Therefore, in the seventh embodiment, the regulator vapor flows from the upper port of the rectifier 2 into the regulator regenerator 9 of the operating condition adjustment module, and the solvent vapor flows from the lower port of the rectifier 2 into the solvent regenerator 3.

[0087] like Figure 8As shown, the specific structure of a mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet provided in accordance with the eighth embodiment of the present invention is explained. The eighth embodiment is a modified embodiment of the fourth embodiment. Specifically, unlike the fourth embodiment, the boiling point of the regulator used in the eighth embodiment is higher than the boiling point of the solvent. Therefore, in the eighth embodiment, the regulator vapor flows from the upper port of the rectifier 2 into the regulator regenerator 9 of the operating condition adjustment module, and the solvent vapor flows from the lower port of the rectifier 2 into the solvent regenerator 3.

[0088] It should be understood that the mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed port of the present invention is a cyclic regenerative power generation system. By utilizing low-grade thermal energy, the intermediate concentration solution can be decomposed into a dilute solution and a concentrated solution and enter the concentration difference power generation module to generate electricity. After the power generation, the dilute solution and the concentrated solution are mixed and can be regenerated again in the heat generation module to complete the power generation cycle.

[0089] It can also be understood that the single-feed-port mixed working fluid reverse electrodialysis low-grade thermal energy power generation system uses a mixed working fluid, and does not produce other harmful substances during the power generation process, and does not pollute the environment. Therefore, it provides an environmentally friendly and environmentally friendly power generation system.

[0090] In general, the mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed port of the present invention utilizes reverse electrodialysis technology to convert low-grade waste heat into chemical potential energy, and utilizes the concentration difference between salt solutions to convert chemical potential energy into electrical energy, thereby realizing efficient recovery and utilization of low-grade waste heat, which is beneficial to improving the overall utilization efficiency of waste heat resources. Moreover, the mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed port of the present invention introduces a solubilizer and a regulator, and uses a solution with a low boiling point and low latent heat of vaporization as a solubilizer, which is beneficial to reducing the energy consumption and vacuum degree of the heat generation module; at the same time, the regulator is used to adjust the conductivity of the solution, which is beneficial to improving the conductivity of the salt solution, thereby reducing the internal resistance loss and giving full play to the complementary advantages of the mixed working fluid; in addition, the structure of the entire system is optimized to ensure a simple structure, reliable operation, adjustable parameters and good heat recovery effect. In addition, the single-feed mixed working fluid reverse electrodialysis low-grade thermal energy power generation system of the present invention has a simple system structure and no moving parts. Its core components such as ion exchange membranes and generators have mature applications in the electrodialysis industry and distillation separation industry, so it is easy to commercialize and put into actual industrial production.

[0091] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, 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, they should be considered to be within the scope of this specification.

[0092] The above embodiments only express the preferred implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for those of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet, characterized in that: It comprises 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, wherein the heat generation module contains an intermediate concentration solution and is configured to be driven by low-grade thermal energy, and is used to convert the low-grade thermal energy into chemical potential energy generated by the concentration difference between salt solutions, so as to separate the intermediate concentration solution into a regulator, a solvent, and an initial concentrated solution, wherein the working condition adjustment module is used to adjust the conductivity, temperature, pressure, and flow rate of the regulator, the solvent, and the initial concentrated solution, respectively, so as to output a dilute solution and a concentrated solution to the concentration difference power generation module, wherein the concentration difference power generation module is used to perform reverse electrodialysis power generation based on the salt concentration difference between the dilute solution and the concentrated solution, wherein the dilute solution and the concentrated solution of the concentration difference power generation module that have completed the power generation process flow into the working condition adjustment module to form the intermediate concentration solution, and the intermediate concentration solution flows into the heat generation module to perform a regeneration process; The heat generation module includes a generator and a rectifier connected to the generator, the operating condition adjustment module includes a solvent condenser, a dilute solution mixer and a dilute solution pump arranged in sequence, the operating condition adjustment module also includes a regulator condenser, a regulator splitter, a concentrated solution mixer and a concentrated solution pump arranged in sequence, the generator is used to convert low-grade thermal energy into chemical potential energy, so that the intermediate concentration solution is separated into a mixture of a regulator and a solvent and the initial concentrated solution, wherein the initial concentrated solution flows in whole or in part into the concentrated solution mixer, wherein the mixture of the regulator and the solvent flows into the rectifier for distillation, and the regulator vapor and the solvent vapor are output respectively, wherein the regulator vapor is condensed and cooled by the regulator condenser to form The regulator liquid is split by the regulator splitter, a part of which flows into the concentrated solution mixer, and is mixed with the initial concentrated solution to form the concentrated solution. The concentrated solution flows into the concentration difference power generation module through the concentrated solution pump, and the other part of the regulator liquid flows into the dilute solution mixer or the heat generation module; wherein the solvent vapor flows into the solvent condenser for condensation and cooling to form a solvent liquid, the solvent liquid flows into the dilute solution mixer for conductivity and concentration adjustment, and forms the dilute solution with any one or more of the regulator liquid, the intermediate concentration solution and the initial concentrated solution, and the dilute solution flows into the dilute solution pump for pressure adjustment and then flows into the concentration difference power generation module.

2. The mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet according to claim 1 is characterized in that: The operating condition adjustment module also includes a concentrated solution regenerator connected to the generator, a regulator regenerator connected to the rectifier, the regulator condenser and the concentrated solution regenerator, a solvent regenerator connected to the rectifier and the solvent condenser, and a temperature equalizer connected to the dilute solution pump, the concentrated solution pump and the concentration difference power generation module, wherein the concentrated solution regenerator is used to perform heat recovery treatment on the initial concentrated solution to reduce the temperature of the initial concentrated solution, the regulator regenerator is used to perform heat recovery treatment on the regulator vapor to reduce the temperature of the regulator vapor, the solvent regenerator is used to perform heat recovery treatment on the solvent vapor to reduce the temperature of the solvent vapor, and the temperature equalizer is used to regulate the temperature of the dilute solution and the concentrated solution.

3. The mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet according to claim 2 is characterized in that: The thermostat is a two-stream heat exchange type thermostat or a three-stream heat exchange type thermostat.

4. The mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet according to claim 2 is characterized in that: The operating condition adjustment module also includes a solution mixer connected to the concentration difference power generation module and a throttle valve connected to the solution mixer. The dilute solution and the concentrated solution that complete the power generation process of the concentration difference power generation module flow into the solution mixer to form the intermediate concentration solution. After the intermediate concentration solution is throttled and reduced in pressure by the throttle valve, all of the intermediate concentration solution is sequentially heat-recovered by the solvent regenerator, the rectifier, the regulator regenerator and the concentrated solution regenerator before flowing into the heat generation module, or a part of the intermediate concentration solution flows into the dilute solution mixer, and the other part of the intermediate concentration solution flows into the heat generation module after being heat-recovered by the solvent regenerator, the rectifier, the regulator regenerator and the concentrated solution regenerator.

5. The mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet according to claim 4 is characterized in that: The operating condition adjustment module also includes an intermediate concentration solution diverter connected to the throttle valve and the dilute solution mixer, wherein the intermediate concentration solution output by the throttle valve is diverted by the intermediate concentration solution diverter, a part of which flows into the dilute solution mixer, and the other part flows into the heat generation module after being heat-recovered by the solvent regenerator, the rectifier, the regulator regenerator and the concentrated solution regenerator in sequence.

6. The mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet according to claim 4 is characterized in that: The operating condition adjustment module also includes a concentrated solution diverter connected to the concentrated solution regenerator, the concentrated solution mixer and the dilute solution mixer. The concentrated solution diverter is used to divert the initial concentrated solution after heat recovery treatment by the concentrated solution regenerator. A part of the initial concentrated solution flows into the concentrated solution mixer, and the other part flows into the dilute solution mixer.

7. The mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet according to claim 5 is characterized in that: The operating condition adjustment module also includes a concentrated solution diverter connected to the concentrated solution regenerator, the concentrated solution mixer and the dilute solution mixer. The concentrated solution diverter is used to divert the initial concentrated solution after heat recovery treatment by the concentrated solution regenerator. A part of the initial concentrated solution flows into the concentrated solution mixer, and the other part flows into the dilute solution mixer.

8. The mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet according to claim 5, characterized in that: The operating condition adjustment module also includes a regulator mixer connected to the intermediate concentration solution diverter, the regulator diverter and the solvent regenerator, wherein a portion of the regulator liquid diverted by the regulator diverter and a portion of the intermediate concentration solution diverted by the intermediate concentration solution diverter flow into the regulator mixer for mixing, and then successively pass through the solvent regenerator, the rectifier, the regulator regenerator and the concentrated solution regenerator for heat recovery treatment before flowing into the heat generation module.

9. The mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet according to claim 7, characterized in that: The operating condition adjustment module also includes a regulator mixer connected to the intermediate concentration solution diverter, the regulator diverter and the solvent regenerator, wherein a portion of the regulator liquid diverted by the regulator diverter and a portion of the intermediate concentration solution diverted by the intermediate concentration solution diverter flow into the regulator mixer for mixing, and then successively pass through the solvent regenerator, the rectifier, the regulator regenerator and the concentrated solution regenerator for heat recovery treatment before flowing into the heat generation module.

10. The mixed working medium reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet according to claim 7 or 9, characterized in that: The adjustment range of the split ratio of the regulator splitter, the intermediate concentration solution splitter and the concentrated solution splitter is 0% to 100%.

11. The mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet according to any one of claims 2 to 9, characterized in that: The working condition adjustment module further includes a dilute solution storage tank and a concentrated solution storage tank, wherein the dilute solution storage tank is disposed between the dilute solution mixer and the dilute solution pump and is used to adjust the flow rate of the dilute solution output by the dilute solution mixer; The concentrated solution storage tank is disposed between the concentrated solution mixer and the concentrated solution pump, and is used to adjust the flow rate of the concentrated solution output by the concentrated solution mixer.

12. The mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet according to any one of claims 2 to 9, characterized in that: The mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet adopts a mixed working fluid to generate electricity, wherein the mixed working fluid comprises a solute, the regulator and the solvent, wherein the solute is composed of one or more pairs of anions and cations, wherein the cations comprise 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 and ammonium ions; wherein the anions comprise 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 and chromate ions; Or the solute is composed of one or more liquids, including water, ethanol, methanol, gasoline, diesel, kerosene, acetonitrile, ether, acetone, isopropanol, hexafluoroisopropanol, trifluoroethanol, trifluoroacetic acid, tetrafluorofuran, dimethylformamide, dimethylacetamide; The polarity of the regulator is higher than that of the solvent, and 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, ethyl ether, isopropyl ether, n-butyl ether, trichloroethylene, diphenyl ether, dichloromethane, dichloroethane, toluene, carbon tetrachloride, carbon disulfide, cyclohexane, hexane, and kerosene; 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, ethyl ether, isopropyl ether, n-butyl ether, trichloroethylene, diphenyl ether, dichloromethane, dichloroethane, toluene, carbon tetrachloride, carbon disulfide, cyclohexane, hexane, and kerosene.

13. The mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet according to any one of claims 2 to 9, 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 allow the dilute solution and the concentrated solution output by the operating condition adjustment module to flow and transfer mass at the same time 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 to the outside through the external circuit.

14. The mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet according to claim 13, characterized in that: The ion exchange membrane comprises 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.

15. The mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet according to claim 13, characterized in that: The reverse electrodialysis cell stack adopts any one of the following arrangements: a single cell, multiple cells in series, multiple cells in parallel, or a mixture of multiple cells 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 liquid is a separate redox working fluid pair or the dilute solution and the concentrated solution.

16. The mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet according to any one of claims 2 to 9, characterized in that: The generator has an upper outlet and a lower outlet. The 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 operating condition adjustment module through the lower outlet of the generator.

17. The mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet according to claim 16, characterized in that: The rectifier has an upper opening and a lower opening, the regulator vapor flows into the operating condition adjustment module through the lower opening of the rectifier, and the solvent vapor flows into the operating condition adjustment module through the upper opening of the rectifier.

18. The mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet according to claim 16, characterized in that: The rectifier has an upper opening and a lower opening, the regulator vapor flows into the operating condition adjustment module through the upper opening of the rectifier, and the solvent vapor flows into the operating condition adjustment module through the lower opening of the rectifier.

19. The mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet according to any one of claims 2 to 9, characterized in that: The dilute solution pump and the concentrated solution pump are any one of volumetric, dynamic and diaphragm types, and are arranged in any form of a single pump, multiple pumps in series, multiple pumps in parallel or a combination of multiple pumps in series and parallel.

20. The mixed working fluid reverse electrodialysis low-grade thermal energy power generation system with a single feed inlet according to any one of claims 2 to 9, characterized in that: The solvent condenser and the regulator condenser exchange heat by using any one of air natural convection heat exchange, air forced convection heat exchange, air mixed convection heat exchange, radiation heat exchange, liquid natural convection heat exchange and liquid forced convection heat exchange, and adopt any one of the layout forms of a single unit, multiple units in series, multiple units in parallel or multiple units in series and parallel mixed.

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