Search

CN-121988474-A - Phosphate quantitative spraying system and corrosion prevention method for phosphoric acid fuel cell

CN121988474ACN 121988474 ACN121988474 ACN 121988474ACN-121988474-A

Abstract

The invention relates to the technical field of phosphoric acid fuel cells, and discloses a phosphate quantitative spraying system and an anti-corrosion method of a phosphoric acid fuel cell. The control module calculates and sets flow to drive the metering pump according to the technological parameters, dynamically corrects the volumetric efficiency coefficient of the metering pump based on the actual coating quantity error fed back by the weight detection module, and realizes closed-loop quantitative control. The system monitors pipeline back pressure in real time by using a pressure sensor, when the pressure deviation exceeds a preset threshold value, the three-way switching valve is automatically controlled to be communicated with the cleaning liquid storage tank, the metering pump is driven to output pulse flow to carry out self-adaptive cleaning on the pipeline and the spray head, and pipeline replacement and anti-corrosion treatment are carried out after the operation is finished. The invention effectively solves the technical problems of large metering deviation of phosphate spraying and easy moisture absorption and blockage of pipelines.

Inventors

  • LU CONG

Assignees

  • 中科润谷智慧能源科技(佛山)有限公司

Dates

Publication Date
20260508
Application Date
20260210

Claims (10)

  1. 1. The phosphate quantitative spraying system of the phosphoric acid fuel cell is characterized by comprising a phosphate storage tank (1), wherein the phosphate storage tank (1) is used for storing phosphate slurry; -a stirrer (12), the stirrer (12) being mounted on the phosphate tank (1), the stirrer (12) being for stirring the phosphate slurry; a cleaning liquid storage tank (2), the cleaning liquid storage tank (2) being used for storing a cleaning medium; The three-way switching valve (3) is provided with a first input port, a second input port and a public output port, the first input port is communicated with the phosphate storage tank (1), and the second input port is communicated with the cleaning liquid storage tank (2); the inlet end of the metering pump (4) is connected with the public output port of the three-way switching valve (3); An acid-resistant conveying pipeline (5), wherein one end of the acid-resistant conveying pipeline (5) is connected with the outlet end of the metering pump (4); The spray head (7) is connected to the other end of the acid-resistant conveying pipeline (5); The pressure sensor (6) is arranged on the acid-resistant conveying pipeline (5), the pressure sensor (6) is positioned close to the spray head (7), and the pressure sensor (6) is used for collecting the fluid pressure in the acid-resistant conveying pipeline (5); the spraying platform (8) is positioned below the spray head (7), and the spraying platform (8) is used for bearing an electrode to be sprayed and driving the electrode to be sprayed to move relative to the spray head (7); The gas collecting cover (9) is arranged above the spraying platform (8) or moves along with the spray head (7), and the gas collecting cover (9) is used for surrounding a spraying area and collecting waste liquid; a weight detection module (10), wherein the weight detection module (10) is arranged on the spraying platform (8) and is used for detecting the weight of the electrode to be sprayed, and The control module (11) is electrically connected with the stirrer (12), the three-way switching valve (3), the metering pump (4), the pressure sensor (6), the spraying platform (8) and the weight detection module (10) respectively, and the control module (11) is configured to receive signals of the pressure sensor (6) and the weight detection module (10) and control the rotating speed of the stirrer (12), the switching state of the three-way switching valve (3) and the operation parameters of the metering pump (4).
  2. 2. The phosphate metering spray system of a phosphoric acid fuel cell according to claim 1, wherein the three-way switching valve (3) is an acid-resistant electric ball valve or a pneumatic angle seat valve, and the control module (11) is configured to control the three-way switching valve (3) to communicate the first input port with the common output port in a spray operation mode and to control the three-way switching valve (3) to communicate the second input port with the common output port in a purge maintenance mode.
  3. 3. The phosphate quantitative spraying system of the phosphoric acid fuel cell according to claim 1, wherein the pressure sensor (6) is a flush diaphragm type pressure transmitter, a pressure sensing diaphragm of the pressure sensor (6) is made of tantalum, hastelloy or ceramic, the pressure sensor (6) is installed at the tail end of the acid-resistant conveying pipeline (5) in series, and the length of a pipeline between the pressure sensor (6) and a liquid inlet of the spray head (7) is smaller than 10 cm.
  4. 4. The phosphate dosing spray system of a phosphoric acid fuel cell according to claim 1, characterized in that the paddles of the agitator (12) extend to the inner bottom end of the phosphate tank (1), the control module (11) being configured to drive the agitator (12) to run at a constant rotational speed to prevent sedimentation of the phosphate slurry.
  5. 5. The phosphate quantitative spraying system of a phosphoric acid fuel cell according to claim 1, wherein the gas-collecting hood (9) is a semi-closed cavity made of transparent corrosion-resistant material, and a flow guiding structure is arranged at the bottom or at the side edge of the gas-collecting hood (9), and is connected to an external waste liquid collecting container.
  6. 6. The phosphate dosing spray system of a phosphoric acid fuel cell according to claim 1, characterized in that the weight detection module (10) is mounted between the base and the carrying floor of the spray platform (8), the control module (11) is configured to calculate the relative error of the actual coating amount and the target coating amount based on the difference of the weights before and after spraying fed back by the weight detection module (10), and to adjust the volumetric efficiency coefficient of the metering pump (4) of the next spray cycle based on the relative error.
  7. 7. The phosphate quantitative spraying system of the phosphoric acid fuel cell according to claim 1, wherein the metering pump (4) is a precision ceramic plunger pump or an acid-resistant gear pump, an overflow part of the metering pump (4) is made of acid-resistant materials, and the acid-resistant conveying pipeline (5) is a soluble polytetrafluoroethylene hose or a stainless steel hard tube.
  8. 8. The phosphate quantitative spraying system of a phosphoric acid fuel cell according to claim 1, wherein an outlet pipeline of the cleaning liquid storage tank (2) is provided with a one-way valve structure for preventing fluid from flowing back, and the spraying platform (8) comprises an X-axis module, a Y-axis module and a Z-axis module, wherein the X-axis module, the Y-axis module and the Z-axis module are driven by a servo motor or a stepping motor.
  9. 9. The phosphate quantitative spraying system of a phosphoric acid fuel cell according to claim 1, wherein a reference spraying back pressure value and a pressure abnormality judgment threshold value are stored in the control module (11), the control module (11) is configured to calculate a deviation coefficient between a real-time pressure value fed back by the pressure sensor (6) and the reference spraying back pressure value, and when the deviation coefficient is larger than the pressure abnormality judgment threshold value and the real-time pressure value is larger than the reference spraying back pressure value, the control module (11) executes an adaptive cleaning program to control the spraying platform (8) to move the spray head (7) to a waste liquid collecting area below the gas collecting hood (9), control the three-way switching valve (3) to be communicated with the cleaning liquid storage tank (2), and control a flow of pressure fluctuation output by the metering pump (4) to flush the acid-resistant conveying pipeline (5) and the spray head (7).
  10. 10. A method of corrosion protection based on phosphate dosing of a phosphoric acid fuel cell of the system of any one of claims 1 to 9, characterized by the steps of: Step 100, the control module (11) performs system initialization, controls the three-way switching valve (3) to be communicated with the phosphate storage tank (1), drives the metering pump (4) to fill a pipeline, and obtains the reference spraying back pressure in the acid-resistant conveying pipeline (5); Step 200, the control module (11) obtains the initial weight of the electrode to be sprayed by utilizing the weight detection module (10); Step 300, the control module (11) drives the metering pump (4) and the spraying platform (8) to execute spraying operation according to preset process target parameters, and monitors the real-time working pressure in the acid-resistant conveying pipeline (5) in real time by utilizing the pressure sensor (6); Step S400, the control module (11) compares the real-time working pressure with the reference spraying back pressure, when the deviation of the real-time working pressure and the reference spraying back pressure exceeds an allowable range and accords with a blocking characteristic, the three-way switching valve (3) is controlled to be switched to the cleaning liquid storage tank (2), and the metering pump (4) is driven to execute cleaning operation on the acid-resistant conveying pipeline (5) and the spray head (7) by utilizing the cleaning medium; Step S500, after the spraying is finished, the control module (11) acquires the final weight of the electrode to be sprayed by utilizing the weight detection module (10), calculates the actual coating amount according to the final weight and the initial weight, and corrects the control parameter of the next spraying period based on the deviation of the actual coating amount and the target loading amount; And S600, after the spraying task is finished, the control module (11) controls the three-way switching valve (3) to be communicated with the cleaning liquid storage tank (2), and the cleaning medium is utilized to replace the phosphate slurry in the acid-resistant conveying pipeline (5), so that the acid-resistant conveying pipeline (5) is in an anti-corrosion protection state.

Description

Phosphate quantitative spraying system and corrosion prevention method for phosphoric acid fuel cell Technical Field The invention relates to the technical field of phosphoric acid fuel cells, in particular to a phosphate quantitative spraying system and an anti-corrosion method of a phosphoric acid fuel cell. Background Phosphoric Acid Fuel Cells (PAFCs) are highly efficient chemical power supplies that utilize concentrated phosphoric acid as an electrolyte, and are widely used in the fields of distributed power generation and backup power supplies. In the preparation process of the membrane electrode of the phosphoric acid fuel cell, the loading of the phosphoric acid electrolyte or the phosphate slurry onto the porous electrode substrate is a key step in determining the performance of the cell. The loading (i.e., loading) of phosphate on the electrode surface and the uniformity of distribution directly affect proton conduction efficiency, three-phase interfacial reactivity, and the end life of the battery. Therefore, the quantitative coating of the phosphate slurry is realized by adopting an automatic spraying system, and is a core link in the current battery manufacturing process. Existing phosphate spraying techniques typically employ mechanical spraying devices based on volumetric metering pumps for operation. In the prior art, the system mainly comprises a liquid storage tank, a delivery pump, a transfusion pipeline and an atomization nozzle. During operation, an operator presets the rotating speed or frequency of the metering pump and the moving speed of the spraying platform, and the system conveys phosphate slurry to the spray head at constant theoretical flow according to preset technological parameters and atomizes and sprays the phosphate slurry to the surface of the electrode. In the production process, open-loop control is usually performed by means of the corresponding relation between the pump speed and the flow established in the equipment debugging stage, namely, the output flow of the default pump is kept constant in the whole working period, so that the phosphate load amount in unit area is controlled. However, the conventional open-loop control method has the defect of difficult quantitative accuracy in practical application. Because phosphate slurries are typically non-newtonian in nature, their viscosity is extremely sensitive to temperature changes and shear forces, and moreover, the internal components of the metering pump inevitably wear mechanically over time, these factors result in deviations between the actual output flow of the pump and the preset theoretical flow. Under the condition of lacking a real-time detection and feedback correction mechanism, the system cannot sense and compensate flow fluctuation caused by the physical property change of the fluid or the equipment state change, so that the phosphate load actually coated on the electrode deviates from a target value, and the consistency and stability of the membrane electrode product performance in mass production are seriously affected. Disclosure of Invention In order to overcome the defects in the prior art, the invention provides a phosphate quantitative spraying system and an anti-corrosion method of a phosphoric acid fuel cell, and solves the problems in the prior art. In order to achieve the above purpose, the invention is realized by the following technical scheme: in a first aspect, the invention provides a phosphate metering spray system for a phosphoric acid fuel cell. The system mainly comprises a feeding unit, a fluid conveying unit, a spraying executing unit and a detection control unit. The feeding unit comprises a phosphate storage tank for storing phosphate slurry and a cleaning liquid storage tank for storing a cleaning medium, wherein a stirrer is arranged on the phosphate storage tank and used for keeping the slurry uniformly dispersed. The core component of the fluid conveying unit comprises a three-way switching valve and a metering pump, wherein the input end of the three-way switching valve is respectively connected with the phosphate storage tank and the cleaning liquid storage tank, the output end of the three-way switching valve is connected with the inlet of the metering pump, and the outlet of the metering pump is connected to the spray head through an acid-resistant conveying pipeline. In this system, the critical monitoring components include a pressure sensor mounted at the end of the acid-resistant delivery conduit near the location of the spray head, and a weight detection module disposed on the spray platform. The control module is respectively connected with the execution components and the sensing components to form a closed-loop control framework. Through the hardware layout, the system can realize the rapid switching of the feeding loop and the cleaning loop on a physical level, and the pressure sensor close to the spray head is utilized to capture rheological characteristic cha