Methanol-water concentration proportioning system based on membrane permeation
By using a membrane-permeation-based methanol-water concentration ratio system, which utilizes a proton exchange membrane and a heat exchanger, the problem of difficult concentration control of methanol-water solution in direct methanol fuel cells is solved, achieving simple and easy-to-control concentration ratio and reducing system costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHANGHAI ZHONGHYDROGEN NEW ENERGY TECH CO LTD
- Filing Date
- 2025-06-06
- Publication Date
- 2026-05-12
AI Technical Summary
The concentration of methanol-water solution in existing direct methanol fuel cells is difficult to control, and the pumps in the fuel supply system require high precision, which increases costs.
A methanol-water concentration ratio system based on membrane permeation is adopted. The methanol chamber and the water mixing chamber are separated by a proton exchange membrane. Methanol and pure water are mixed through the proton exchange membrane. Combined with a heat exchanger, the temperature and pressure of methanol are increased, so as to achieve a simple and easy-to-control concentration ratio.
This approach enables easy control of the concentration of methanol-water solution, reduces the precision requirements of the pump, simplifies operation, and lowers system costs.
Smart Images
Figure CN224221266U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the technical field of direct methanol fuel cells, and specifically to a methanol-water concentration ratio system. Background Technology
[0002] A direct methanol fuel cell (DMFC) is a device that uses methanol-water solution as fuel and directly converts chemical energy into electrical energy through an electrochemical reaction. It boasts advantages such as high energy density, easy fuel storage, and rapid low-temperature start-up, making it an ideal power source for portable electronic devices and micro-energy systems. Its core reactions include: Anode reaction: Methanol and water are oxidized under the action of a catalyst to produce CO2, protons, and electrons, with the reaction equation: CH3OH + H2O → CO2 + 6H⁺ + 6e⁻; Cathode reaction: Oxygen combines with protons and electrons to produce water, with the reaction equation: 3 / 2O2 + 6H⁺ + 6e⁻ → 3H2O.
[0003] The fuel for direct methanol fuel cells should be a methanol-water mixture, typically with a concentration of 3% to 5%. Existing fuel supply systems for direct methanol fuel cells generally include a methanol tank, a water tank, and a mixing tank. The methanol tank pumps pure methanol into the mixing tank, and the water tank pumps water into the mixing tank, creating a 3% to 5% methanol-water solution. The disadvantages of this fuel supply system include: 1. The concentration of the methanol-water solution in the mixing tank is difficult to control; 2. Continuously replenishing pure methanol from the methanol tank to the mixing tank requires very high precision from the pump, resulting in a high pump cost.
[0004] Chinese invention patent CN117654319A discloses an automatic fuel proportioning system for a methanol reforming hydrogen production unit, comprising a pure methanol storage tank, a deionized water storage tank, a pure methanol buffer tank, a deionized water buffer tank, and a methanol-water solution storage tank. The outlet of the pure methanol storage tank is connected to the inlet of the pure methanol buffer tank via a diaphragm pump, and the overflow port of the pure methanol buffer tank is connected to the return port of the pure methanol storage tank. The outlet of the pure methanol buffer tank is equipped with a solenoid valve and connected to the methanol-water solution storage tank. The outlet of the deionized water storage tank is connected to the inlet of the deionized water buffer tank via a diaphragm pump, and the overflow port of the deionized water buffer tank is connected to the return port of the deionized water storage tank. The outlet of the deionized water buffer tank is equipped with a solenoid valve and connected to the methanol-water solution storage tank. The weights of pure methanol and deionized water stored in the volumes below the overflow ports of the two buffer tanks are equal. This invention uses the pure methanol storage tank, deionized water storage tank, pure methanol buffer tank, deionized water buffer tank, and methanol-water solution storage tank to proportion the concentration of the methanol-water solution.
[0005] Therefore, the current need is to solve the problem of easily controlling the concentration of methanol-water solution in direct methanol fuel cells. Summary of the Invention
[0006] The purpose of this invention is to overcome the shortcomings of the prior art and to provide a methanol-water concentration ratio system based on membrane permeation.
[0007] To achieve the above objectives, this utility model provides the following technical solution: a methanol-water concentration ratio system based on membrane permeation, comprising a pure methanol storage tank, a pure water storage tank, a methanol-water storage tank, and a diaphragm mixing tank.
[0008] The diaphragm mixing tank includes a first end plate, a proton exchange membrane, and a second end plate. The side of the first end plate is provided with a methanol chamber, and the side of the second end plate is provided with a water mixing chamber. The proton exchange membrane is sandwiched between the first end plate and the second end plate, and the proton exchange membrane separates the methanol chamber and the water mixing chamber on both sides. Methanol in the methanol chamber can permeate through the proton exchange membrane into the water mixing chamber and mix with the pure water in the water mixing chamber.
[0009] The first end plate has a methanol inlet and a methanol outlet at both ends, which are connected to the methanol chamber. The second end plate has a pure water inlet and a methanol-water outlet at both ends, which are connected to the mixed water chamber. The outlet of the pure methanol storage tank is connected to the methanol inlet of the first end plate, the inlet of the pure methanol storage tank is connected to the methanol outlet of the first end plate, the outlet of the pure water storage tank is connected to the pure water inlet of the second end plate, and the methanol-water outlet of the second end plate is connected to the inlet of the methanol-water storage tank.
[0010] Preferably, both the first end plate and the second end plate have sealing grooves on their sides, and sealing rings are embedded in the sealing grooves to ensure the sealing between the first end plate, the second end plate and the proton exchange membrane.
[0011] Preferably, the first end plate and the second end plate are fastened together by a plurality of bolt assemblies.
[0012] Preferably, it also includes a direct methanol fuel cell, wherein the outlet of the methanol-water storage tank is connected to the methanol-water inlet of the direct methanol fuel cell, and the methanol-water outlet of the direct methanol fuel cell is connected to the inlet of the methanol-water storage tank.
[0013] Preferably, the system further includes a heat exchanger having a methanol inlet, a methanol outlet, a water inlet, and a water outlet. The drain outlet of the direct methanol fuel cell is connected to the water inlet of the heat exchanger, the water outlet of the heat exchanger is connected to the inlet of a pure water storage tank, the outlet of the pure methanol storage tank is connected to the methanol inlet of the heat exchanger, and the methanol outlet of the heat exchanger is connected to the methanol inlet of the first end plate.
[0014] Preferably, the methanol-water storage tank is equipped with a methanol concentration sensor for detecting the methanol-water concentration inside the tank.
[0015] Compared with related technologies, the methanol-water concentration ratio system based on membrane permeation provided by this utility model has the following advantages:
[0016] 1. This utility model utilizes the mechanism that the proton exchange membrane allows methanol molecules to diffuse due to its hydrophilic channels, resulting in high methanol permeability. The interior of the membrane mixing tank is divided into a methanol chamber and a water mixing chamber by the proton exchange membrane. Some methanol on the methanol chamber side can permeate into the water mixing chamber through the proton exchange membrane and be mixed with pure water to prepare a methanol-water concentration suitable for direct methanol fuel cells. The operation is simple and the methanol-water concentration is easy to control.
[0017] 2. The high-temperature water output from the drain outlet of the direct methanol fuel cell exchanges heat with the pure methanol output from the pure methanol storage tank in the heat exchanger, increasing the temperature and pressure of the pure methanol liquid, making it easier for the pure methanol to permeate from the methanol chamber into the mixing chamber. Attached Figure Description
[0018] Figure 1 A three-dimensional view of a methanol-water concentration ratio system based on membrane permeation;
[0019] Figure 2 A three-dimensional view of the diaphragm mixing tank;
[0020] Figure 3 This is a three-dimensional view of the first end plate;
[0021] Figure 4 This is a three-dimensional view of the second end plate;
[0022] Figure 5 This is a block diagram of a methanol-water concentration mixing system based on membrane permeation.
[0023] Reference numerals: 1. Pure methanol storage tank; 2. Pure water storage tank; 3. Methanol-water storage tank; 4. Diaphragm mixing tank; 41. First end plate; 411. Methanol chamber; 42. Proton exchange membrane; 43. Second end plate; 431. Mixing chamber; 5. Sealing ring; 6. Bolt assembly; 7. Direct methanol fuel cell; 8. Heat exchanger. Detailed Implementation
[0024] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments.
[0025] It should be noted that in the description of this utility model, terms such as "upper," "lower," "left," and "right," which indicate direction or positional relationship, are based on the direction or positional relationship shown in the accompanying drawings. This is merely for ease of description and does not indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this utility model.
[0026] Furthermore, it should be noted that, in the description of this utility model, unless otherwise explicitly specified and limited, the terms "installation," "setting," and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.
[0027] Example
[0028] Please see Figures 1-5 As shown, the methanol-water concentration mixing system based on membrane permeation provided in this embodiment of the present invention includes a pure methanol storage tank 1, a pure water storage tank 2, a methanol-water storage tank 3, and a diaphragm mixing tank 4. The pure methanol storage tank 1 is used to transport methanol into the diaphragm mixing tank 4, and the pure water storage tank 2 is used to transport pure water into the diaphragm mixing tank 4.
[0029] Specifically, the diaphragm mixing tank 4 includes a first end plate 41, a proton exchange membrane 42, and a second end plate 43 connected in sequence. The proton exchange membrane 42 is sandwiched between the first end plate 41 and the second end plate 43. A methanol chamber 411 is provided in the middle of the side of the first end plate 41 near the proton exchange membrane 42. Methanol supplied from the pure methanol storage tank 1 to the diaphragm mixing tank 4 enters the methanol chamber 411. A water mixing chamber 431 is provided in the middle of the side of the second end plate 43 near the proton exchange membrane 42. Pure water is stored in the water chamber. The pure water delivered from tank 2 to the diaphragm mixing tank 4 enters the mixing chamber 431. The proton exchange membrane 42 separates the methanol chamber 411 and the mixing chamber 431 on the left and right sides. Some of the pure methanol in the methanol chamber 411 can permeate through the proton exchange membrane 42 into the mixing chamber 431 and mix with the pure water in the mixing chamber 431. By adjusting the flow rate and pressure of pure methanol and pure water, the methanol-water concentration is adjusted to 3%~5%, which can then be input into the direct methanol fuel cell 7 for use.
[0030] The first end plate 41 has a methanol inlet and a methanol outlet at both ends, respectively, which are connected to the methanol chamber 411. The outlet of the pure methanol storage tank 1 is connected to the methanol inlet of the first end plate 41 via a pump and a pipeline, and the methanol outlet of the first end plate 41 is connected to the inlet of the pure methanol storage tank 1 via a pump and a pipeline. Methanol in the pure methanol storage tank 1 is transported from the methanol inlet to the methanol chamber 411, and methanol in the impermeable mixed water chamber 431 flows back to the pure methanol storage tank 1 from the methanol outlet.
[0031] The second end plate 43 has a pure water inlet and a methanol water outlet at both ends, which are connected to the mixing chamber 431. The outlet of the pure water storage tank 2 is connected to the pure water inlet of the second end plate 43 via a pump and a pipeline, and the methanol water outlet of the second end plate 43 is connected to the inlet of the methanol water storage tank 3 via a pump and a pipeline. The pure water in the pure water storage tank 2 is transported from the pure water inlet to the mixing chamber 431, where it mixes with the methanol that permeates from the methanol chamber 411 to form a methanol-water solution. The methanol-water solution is then transported from the methanol water outlet to the methanol-water storage tank 3.
[0032] The above are merely preferred embodiments of the present utility model and do not limit the implementation methods and protection scope of the present utility model. The present utility model also has the following embodiments based on the above:
[0033] In this embodiment, in order to ensure the seal between the first end plate 41, the second end plate 43 and the proton exchange membrane 42, sealing grooves are provided on the sides of both the first end plate 41 and the second end plate 43, and sealing rings 5 are embedded in the sealing grooves. The sealing groove on the first end plate 41 surrounds the outer edge of the methanol chamber 411, and the sealing groove on the second end plate 43 surrounds the outer edge of the mixing chamber 431.
[0034] In this embodiment, the first end plate 41 and the second end plate 43 are fastened together by multiple bolt assemblies 6 to ensure the airtightness of the diaphragm mixing tank 4 and to facilitate disassembly and maintenance.
[0035] In this embodiment, a direct methanol fuel cell 7 is also included. The outlet of the methanol-water storage tank 3 is connected to the methanol-water inlet of the direct methanol fuel cell 7 via a pump and pipeline to supply methanol-water fuel to the direct methanol fuel cell 7. The methanol-water outlet of the direct methanol fuel cell 7 is connected to the inlet of the methanol-water storage tank 3 via a pump and pipeline to return unreacted methanol-water fuel to the methanol-water storage tank 3.
[0036] In this embodiment, a heat exchanger 8 is also included. The heat exchanger 8 has a methanol inlet, a methanol outlet, a water inlet, and a water outlet. The drain outlet of the direct methanol fuel cell 7 is connected to the water inlet of the heat exchanger 8 via a pump and a pipeline. The water outlet of the heat exchanger 8 is connected to the inlet of the pure water storage tank 2, allowing water output from the direct methanol fuel cell 7 to flow back into the pure water storage tank 2. The outlet of the pure methanol storage tank 1 is connected to the methanol inlet of the heat exchanger 8 via a pump and a pipeline. The methanol outlet of the heat exchanger 8 is connected to the methanol inlet of the first end plate 41. The high-temperature water output from the drain outlet of the direct methanol fuel cell 7 exchanges heat with the pure methanol output from the pure methanol storage tank 1 in the heat exchanger 8, increasing the temperature and pressure of the pure methanol liquid, making it easier for pure methanol to permeate from the methanol chamber 411 into the mixing chamber 431.
[0037] In this embodiment, a methanol concentration sensor is installed in the methanol-water storage tank 3 to detect the methanol-water concentration value in the methanol-water storage tank 3. Then, by adjusting the pressure and temperature, the amount of pure methanol in the methanol chamber 411 permeates through the proton exchange membrane 42 into the mixing chamber 431 is controlled to adjust the methanol-water concentration to 3%~5%.
[0038] In this embodiment, the proton exchange membrane 42 is a short-chain perfluorosulfonic acid membrane. Because the hydrophilic channels allow methanol molecules to diffuse and the methanol permeability is high, the perfluorosulfonic acid membrane with model number FUMAPEM® FS-990-PK from FUMATECH BWT GmbH in Germany is preferred.
[0039] It should be noted that, in this document, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.
[0040] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A methanol-water concentration mixing system based on membrane permeation, comprising a pure methanol storage tank (1), a pure water storage tank (2), and a methanol-water storage tank (3), characterized in that, Also includes: Diaphragm mixing tank (4); The diaphragm mixing tank (4) includes a first end plate (41), a proton exchange membrane (42), and a second end plate (43). The side of the first end plate (41) is provided with a methanol chamber (411), and the side of the second end plate (43) is provided with a water mixing chamber (431). The proton exchange membrane (42) is sandwiched between the first end plate (41) and the second end plate (43). The proton exchange membrane (42) separates the methanol chamber (411) and the water mixing chamber (431) on both sides. Methanol in the methanol chamber (411) can permeate into the water mixing chamber (431) through the proton exchange membrane (42). The first end plate (41) is provided with a methanol inlet and a methanol outlet communicating with the methanol chamber (411) at both ends, and the second end plate (43) is provided with a pure water inlet and a methanol water outlet communicating with the mixing chamber (431) at both ends, respectively. The outlet of the pure methanol storage tank (1) is connected to the methanol inlet of the first end plate (41), the inlet of the pure methanol storage tank (1) is connected to the methanol outlet of the first end plate (41), the outlet of the pure water storage tank (2) is connected to the pure water inlet of the second end plate (43), and the methanol water outlet of the second end plate (43) is connected to the inlet of the methanol water storage tank (3).
2. The methanol-water concentration ratio system based on membrane permeation according to claim 1, characterized in that, The first end plate (41) and the second end plate (43) are both provided with sealing grooves on their sides, and sealing rings (5) are embedded in the sealing grooves.
3. The methanol-water concentration ratio system based on membrane permeation according to claim 2, characterized in that, The first end plate (41) and the second end plate (43) are fastened together by a plurality of bolt assemblies (6).
4. The methanol-water concentration ratio system based on membrane permeation according to claim 1, characterized in that, It also includes a direct methanol fuel cell (7), wherein the outlet of the methanol-water storage tank (3) is connected to the methanol-water inlet of the direct methanol fuel cell (7), and the methanol-water outlet of the direct methanol fuel cell (7) is connected to the inlet of the methanol-water storage tank (3).
5. The methanol-water concentration ratio system based on membrane permeation according to claim 4, characterized in that, It also includes a heat exchanger (8), which has a methanol inlet, a methanol outlet, a water inlet and a water outlet. The drain outlet of the direct methanol fuel cell (7) is connected to the water inlet of the heat exchanger (8), the water outlet of the heat exchanger (8) is connected to the inlet of the pure water storage tank (2), the outlet of the pure methanol storage tank (1) is connected to the methanol inlet of the heat exchanger (8), and the methanol outlet of the heat exchanger (8) is connected to the methanol inlet of the first end plate (41).
6. The methanol-water concentration ratio system based on membrane permeation according to claim 1, characterized in that, A methanol concentration sensor is installed inside the methanol-water storage tank (3).