Pure methanol supply system of direct methanol fuel cell

Abstract

The utility model discloses a pure methanol supply system of a direct methanol fuel cell, which relates to the technical field of direct methanol fuel cells and comprises a pure methanol storage tank, a methanol aqueous solution storage tank, a diaphragm pump and a methanol-water liquid mixer, the methanol-water liquid mixer comprises a barrel and a fan, the fan is mounted in the barrel, and a methanol liquid inlet and a water inlet are formed in the side wall of the barrel; the diaphragm pump is arranged on a connecting pipeline between a liquid outlet of the pure methanol storage tank and a methanol liquid inlet of the cylinder body, an outlet of the cylinder body is connected with a liquid inlet of the methanol aqueous solution storage tank, and a liquid outlet of the methanol aqueous solution storage tank is connected with a methanol water liquid inlet of the direct methanol fuel cell; and a water outlet of the direct methanol fuel cell is connected with a water inlet of the barrel. The heat exchanger is used for vaporizing methanol, the diaphragm pump can feed liquid in vacuum, the conveying flow of pure methanol is easier to control, and the cost is low; water output by the cathode of the direct methanol fuel cell is circularly used as a water source and is input into the methanol-water liquid mixer to be uniformly mixed.

Description

Technical Field

[0001] This utility model relates to the technical field of direct methanol fuel cells, and specifically to a pure methanol supply system for direct methanol fuel cells. 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] Traditional direct methanol fuel cells require a continuous supply of methanol-water solution (typically 3%–5% concentration), while water, as one of the reactants, needs to be replenished from an external water source, increasing system complexity and volume. Furthermore, if the water generated at the cathode is not effectively utilized, it can lead to flooding, hindering oxygen transport and reducing battery performance. Therefore, how to utilize the water generated internally as a fuel water source through recycling has become a key technological direction for improving the energy density and self-sufficiency of direct methanol fuel cells.

[0004] like Figure 1 As shown, the fuel supply system of existing direct methanol fuel cells generally includes 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, thus preparing a 3% to 5% methanol-water solution in the mixing tank. The disadvantages of this fuel supply system are: 1. The mixing tank is large; 2. The concentration of the methanol-water solution in the mixing tank is difficult to control; 3. The replenishment of pure methanol from the methanol tank to the mixing tank is intermittent. If continuous replenishment is required, the pump precision requirements are very high, and the pump price is very high.

[0005] 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 adjust the concentration of the methanol-water solution.

[0006] Therefore, the current need is to solve the problems of low cost and easy control of methanol aqueous solution concentration in direct methanol fuel cells. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of the prior art and to provide a pure methanol supply system for a direct methanol fuel cell.

[0008] To achieve the above objectives, this utility model provides the following technical solution: a pure methanol supply system for a direct methanol fuel cell, comprising: a pure methanol storage tank and a methanol-water solution storage tank, wherein the pure methanol storage tank stores pure methanol and the methanol-water solution storage tank stores methanol-water solution; further comprising: a diaphragm pump and a methanol-water mixer.

[0009] The methanol-water mixer includes a cylinder and a blower. The inside of the cylinder is a mixing chamber. The cylinder has an inlet and an outlet at its two ends. The blower is installed inside the cylinder, forming an airflow channel from the inlet, the mixing chamber, and the outlet within the cylinder. The side wall of the cylinder has a methanol inlet and a water inlet that communicate with the mixing chamber. The blower introduces external air into the cylinder through the inlet.

[0010] The diaphragm pump is installed on the connecting pipe between the outlet of the pure methanol storage tank and the methanol inlet of the cylinder. The outlet of the cylinder is connected to the inlet of the methanol-water solution storage tank, the outlet of the methanol-water solution storage tank is connected to the methanol-water inlet of the direct methanol fuel cell, the methanol-water outlet of the direct methanol fuel cell is connected to the inlet of the methanol-water solution storage tank, and the drain outlet of the direct methanol fuel cell is connected to the water inlet of the cylinder. Pure methanol and water are mixed evenly in the cylinder under the action of the fan.

[0011] Preferably, the system also 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 water inlet of the cylinder, 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 inlet of the diaphragm pump. 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, causing the pure methanol to vaporize.

[0012] Preferably, an air filter is provided at the inlet of the cylinder.

[0013] Preferably, the methanol-water solution storage tank is equipped with a methanol concentration sensor for detecting the concentration of the methanol-water solution.

[0014] Preferably, a first water pump is provided on the connecting pipe between the outlet of the methanol-water solution storage tank and the inlet of the methanol-water solution of the direct methanol fuel cell, a second water pump is provided on the connecting pipe between the outlet of the methanol-water solution of the direct methanol fuel cell and the inlet of the methanol-water solution storage tank, and a third water pump is provided on the connecting pipe between the outlet of the direct methanol fuel cell and the inlet of the cylinder.

[0015] Compared with related technologies, the pure methanol supply system for a direct methanol fuel cell provided by this utility model has the following beneficial effects:

[0016] 1. This utility model utilizes a heat exchanger to vaporize methanol output from a pure methanol storage tank. The diaphragm pump can adjust the vacuum level and boiling point. Using a diaphragm pump makes it easier to control the flow rate of pure methanol and is also low in cost.

[0017] 2. The water output from the cathode of the direct methanol fuel cell is used as a water source and input into the methanol-water mixer. Under the action of the fan, a negative pressure is generated inside the cylinder, and pure methanol and water are injected into the cylinder, mixed evenly, and then input into the methanol-water solution storage tank. Attached Figure Description

[0018] Figure 1 This refers to the fuel supply system for existing direct methanol fuel cells;

[0019] Figure 2 A three-dimensional diagram of a pure methanol supply system for a direct methanol fuel cell;

[0020] Figure 3 A top view of a pure methanol supply system for a direct methanol fuel cell;

[0021] Figure 4 A three-dimensional view of a methanol-water mixer;

[0022] Figure 5 This is a structural block diagram of a pure methanol supply system for a direct methanol fuel cell.

[0023] Figure 6 A three-dimensional view of the pure methanol supply system and its supporting structure.

[0024] Reference numerals: 1. Pure methanol storage tank; 2. Methanol-water solution storage tank; 3. Diaphragm pump; 4. Methanol-water mixer; 41. Shell; 42. Fan; 5. Direct methanol fuel cell; 6. Heat exchanger; 7. First water pump; 8. Second water pump; 9. Third water pump; 10. Support bracket. Detailed Implementation

[0025] 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.

[0026] 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.

[0027] 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. Example

[0028] Please see Figures 2-5 As shown, the pure methanol supply system for a direct methanol fuel cell provided in this embodiment includes a pure methanol storage tank 1, a methanol-water solution storage tank 2, a diaphragm pump 3, and a methanol-water mixer 4. The pure methanol storage tank 1 is used to store pure methanol, the methanol-water solution storage tank 2 is used to store methanol-water solution, and the diaphragm pump 3 is used to input the pure methanol in the pure methanol storage tank 1 into the methanol-water mixer 4 in a vacuum form. Using the diaphragm pump 3 makes it easier to control the flow rate of pure methanol and has low cost. The water output from the cathode of the direct methanol fuel cell 5 flows back into the methanol-water mixer 4, and the pure methanol and water are mixed in the methanol-water mixer 4.

[0029] Specifically, the methanol-water mixer 4 includes a cylinder 41 and a blower 42. The inside of the cylinder 41 is a cylindrical mixing chamber. The two ends of the cylinder 41 are respectively provided with an inlet for introducing external air into the cylinder 41 and an outlet for outputting the methanol-water mixture. The blower 42 is installed inside the cylinder 41 near the outlet, forming an airflow channel inside the cylinder 41 that connects the inlet, the mixing chamber, and the outlet in sequence. The side wall of the cylinder 41 is provided with a methanol inlet and a water inlet that are connected to the mixing chamber. When the blower 42 rotates, it will create a negative pressure inside the cylinder 41. Pure methanol and water enter the cylinder 41 from the methanol inlet and the water inlet, respectively. Under the action of the airflow, the mixing can be completed quickly.

[0030] The outlet of the pure methanol storage tank 1 is connected to the methanol inlet of the cylinder 41 via a pipeline. A diaphragm pump 3 is installed on the connecting pipeline between the outlet of the pure methanol storage tank 1 and the methanol inlet of the cylinder 41, used to evacuate pure methanol from the pure methanol storage tank 1 into the cylinder 41 in a vacuum manner. The outlet of the cylinder 41 is connected to the inlet of the methanol-water solution storage tank 2, inputting the mixed methanol-water solution in the cylinder 41 into the methanol-water solution storage tank 2. The methanol-water outlet of the methanol-water solution storage tank 2 is connected to the methanol-water inlet of the direct methanol fuel cell 5, used to supply methanol-water solution to the direct methanol fuel cell 5. The methanol-water outlet of the direct methanol fuel cell 5 is connected to the inlet of the methanol-water solution storage tank 2, allowing unreacted methanol-water solution in the direct methanol fuel cell 5 to flow back into the methanol-water solution storage tank 2. The drain outlet of the direct methanol fuel cell 5 is connected to the water inlet of the cylinder 41, allowing water generated inside the direct methanol fuel cell 5 to be transported into the cylinder 41, using the water generated inside the direct methanol fuel cell 5 as a water source.

[0031] It also includes a heat exchanger 6, which has a methanol inlet, a methanol outlet, a water inlet, and a water outlet. The drain outlet of the direct methanol fuel cell 5 is connected to the water inlet of the heat exchanger 6, the water outlet of the heat exchanger 6 is connected to the water inlet of the cylinder 41, the outlet of the pure methanol storage tank 1 is connected to the methanol inlet of the heat exchanger 6, and the methanol outlet of the heat exchanger 6 is connected to the inlet of the diaphragm pump 3. The high-temperature water output from the drain outlet of the direct methanol fuel cell 5 exchanges heat with the pure methanol output from the pure methanol storage tank 1 in the heat exchanger 6, vaporizing the pure methanol liquid.

[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, an air filter (not shown in the figure) is provided at the inlet of the cylinder 41 to filter out impurities in the air.

[0034] In this embodiment, the methanol-water solution storage tank 2 is equipped with a methanol concentration sensor to detect the concentration of the methanol-water solution. Based on the detected methanol-water solution concentration, the flow rate of pure methanol is controlled by the diaphragm pump 3 so that the methanol-water concentration in the methanol-water solution storage tank 2 reaches a preset concentration value.

[0035] In this embodiment, a first water pump 7 is installed on the connecting pipe between the outlet of the methanol-water solution storage tank 2 and the methanol-water inlet of the direct methanol fuel cell 5, for introducing the methanol-water solution into the direct methanol fuel cell 5. A second water pump 8 is installed on the connecting pipe between the methanol-water outlet of the direct methanol fuel cell 5 and the inlet of the methanol-water solution storage tank 2, for returning unreacted methanol-water solution to the methanol-water solution storage tank 2. A third water pump 9 is installed on the connecting pipe between the drain outlet of the direct methanol fuel cell 5 and the inlet of the cylinder 41, for transporting the generated water into the cylinder 41, allowing the water to circulate as a water source.

[0036] In this embodiment, as Figure 6 As shown, the pure methanol storage tank 1, the methanol-water solution storage tank 2, the diaphragm pump 3, and the methanol-water mixer 4 are all mounted on the support bracket 10.

[0037] 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.

[0038] 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 pure methanol supply system for a direct methanol fuel cell, comprising a pure methanol storage tank (1) and a methanol-water solution storage tank (2), wherein the pure methanol storage tank (1) stores pure methanol, characterized in that, Also includes: Diaphragm pump (3) and methanol-water mixer (4); The methanol-water mixer (4) includes a cylinder (41) and a blower (42). The inside of the cylinder (41) is a mixing chamber. The two ends of the cylinder (41) are respectively provided with an inlet and an outlet. The blower (42) is installed inside the cylinder (41). The side wall of the cylinder (41) is provided with a methanol inlet and a water inlet that are connected to the mixing chamber. The diaphragm pump (3) is installed on the connecting pipe between the outlet of the pure methanol storage tank (1) and the methanol inlet of the cylinder (41). The outlet of the cylinder (41) is connected to the inlet of the methanol aqueous solution storage tank (2). The outlet of the methanol aqueous solution storage tank (2) is connected to the methanol water inlet of the direct methanol fuel cell (5). The methanol water outlet of the direct methanol fuel cell (5) is connected to the inlet of the methanol aqueous solution storage tank (2). The drain outlet of the direct methanol fuel cell (5) is connected to the water inlet of the cylinder (41).

2. The direct methanol fuel cell system according to claim 1, wherein It also includes a heat exchanger (6), which has a methanol inlet, a methanol outlet, a water inlet and a water outlet. The drain outlet of the direct methanol fuel cell (5) is connected to the water inlet of the heat exchanger (6), the water outlet of the heat exchanger (6) is connected to the water inlet of the cylinder (41), the outlet of the pure methanol storage tank (1) is connected to the methanol inlet of the heat exchanger (6), and the methanol outlet of the heat exchanger (6) is connected to the inlet of the diaphragm pump (3).

3. The direct methanol fuel cell system according to claim 1, wherein An air filter is provided at the inlet of the cylinder (41).

4. The direct methanol fuel cell system according to claim 1, wherein The methanol-water solution storage tank (2) is equipped with a methanol concentration sensor for detecting the concentration of the methanol-water solution.

5. The direct methanol fuel cell system according to claim 1, wherein A first water pump (7) is provided on the connecting pipe between the outlet of the methanol-water solution storage tank (2) and the inlet of the direct methanol fuel cell (5). A second water pump (8) is provided on the connecting pipe between the outlet of the direct methanol fuel cell (5) and the inlet of the methanol-water solution storage tank (2). A third water pump (9) is provided on the connecting pipe between the outlet of the direct methanol fuel cell (5) and the inlet of the cylinder (41).

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