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CN-121991566-A - Integrated continuous process for spraying, drying, cooling and detecting graphite slurry of PAFC separator of phosphoric acid fuel cell

CN121991566ACN 121991566 ACN121991566 ACN 121991566ACN-121991566-A

Abstract

The invention relates to the technical field of energy power and discloses a spraying-drying-cooling-detecting integrated continuous process for graphite slurry of a PAFC separator of a phosphoric acid fuel cell, wherein the slurry is prepared from raw materials comprising crystalline flake graphite, fluorine modified phenolic resin, polytetrafluoroethylene emulsion, a dispersing agent and a diluting solvent. The process comprises the steps of carrying out double-sided coating by using a spraying station and matching shielding protection, adopting a near infrared heater for drying, generating micro negative pressure by using the linkage of an exhaust hood and a dust collector for cooling and dust collection, and carrying out quality detection by using an online weighing table and a vision system. The core of the invention is to establish a closed-loop self-adaptive compensation mechanism between detection data and spraying execution, and eliminate coating deviation by adjusting slurry parameters in real time. Meanwhile, the blocking of the shielding plate is monitored visually and the on-line switching is triggered, so that the secondary pollution of the bonding surface is eliminated. The invention solves the problems of poor process consistency and low efficiency in the prior art, and improves the corrosion resistance and the production control degree of the separator.

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 PAFC separator graphite slurry for the phosphoric acid fuel cell is characterized by comprising, by weight, 60-80 parts of flake graphite, 10-20 parts of fluorine modified phenolic resin, 1-5 parts of polytetrafluoroethylene emulsion, 1-5 parts of a dispersing agent and 100-150 parts of a diluting solvent.
  2. 2. The graphite slurry for a PAFC separator of a phosphoric acid fuel cell according to claim 1, wherein the purity of the crystalline flake graphite is greater than or equal to 99.9%, the median particle diameter is 8-15 microns, and the dilution solvent consists of deionized water and ethanol in a mass ratio of 7:3 to 9:1.
  3. 3. The graphite slurry for PAFC separator of phosphoric acid fuel cell according to claim 1, wherein the fluorine modified phenolic resin is a random copolymer polymer compound with the number average molecular weight of 3500-4500 g/mol and the molecular weight distribution index of 1.2-1.5, the repeating unit is composed of phenolic hydroxyl structural unit bridged by methylene and benzene ring structural unit with perfluorooctyl side chain, and the fluorine modified phenolic resin is polymerized by phenol, formaldehyde solution and 1H, 2H-perfluoro-1-octanol according to the mole ratio of 1:0.8-0.95:0.08-0.20.
  4. 4. A phosphoric acid fuel cell PAFC separator graphite slurry spray-dry-cool-test integrated continuous process characterized by using the graphite slurry of claim 1 comprising the steps of: step 1, a spraying stage, namely continuously spraying the front and back sides of the partition board by using a spraying station A and a spraying station B, and shielding a reserved area for bonding of the partition board by using a shielding plate during spraying; step 2, a drying stage, namely continuously drying the sprayed partition board by adopting a near infrared heater; Step 3, cooling after drying, and collecting graphite dust by using an exhaust hood and a dust collector; Step 4, a detection stage, namely acquiring weight difference before and after spraying of the partition board by using an online weighing table to calculate the coating amount, and identifying spraying defects on the surface of the coating by using a visual detection system; the coating quantity data obtained in the step 4 are fed back to the spraying control system in the step 1 in real time, and closed-loop self-adaptive compensation of the spraying quantity is realized by adjusting slurry pumping flow or spraying pressure.
  5. 5. The integrated continuous process of spraying, drying, cooling and detecting the graphite slurry of the PAFC separator of the phosphoric acid fuel cell according to claim 4, wherein in the step 1, the slurry accumulation height at the edge of the shielding plate is monitored in real time by a visual sensor, and when the accumulation height reaches 0.2-0.5 mm, an online automatic switching device of the shielding plate is triggered to replace the polluted plate with a clean plate.
  6. 6. The integrated continuous process for spraying, drying, cooling and detecting graphite slurry for PAFC separator of phosphoric acid fuel cell according to claim 4, wherein in step 2, the radiation power density of the near infrared heater is 20 kilowatts to 40 kilowatts per square meter, the temperature of the drying zone is controlled within the range of 120-160 degrees celsius, and the effective drying time is 60-120 seconds.
  7. 7. The integrated continuous process of spraying, drying, cooling and detecting graphite slurry for PAFC separator of phosphoric acid fuel cell according to claim 4, wherein in step 3, the negative pressure of the cooling zone is controlled to be minus 10 to minus 30 pascals, the surface temperature of the separator is ensured to be maintained in the range of 20-30 degrees celsius, and the cooling wind speed is controlled to be 5-12 meters per second.
  8. 8. The integrated continuous process for spraying, drying, cooling and detecting graphite slurry for PAFC separator of phosphoric acid fuel cell according to claim 4, wherein in step 4, when the system determines that the coating weight deviation of 3-5 continuous products exceeds plus or minus 1% of the target value, the spraying control system automatically performs step-by-step compensation adjustment according to the ratio of 1.0% -3.0% of the original flow.
  9. 9. The integrated continuous process for spraying, drying, cooling and detecting the graphite slurry of the PAFC separator of the phosphoric acid fuel cell according to claim 4, wherein the step 1 is preceded by a slurry premixing step, namely, the raw material components are dispersed in a mixing kettle at a high speed, and the fluctuation range of the solid content of the slurry is controlled within plus or minus 2.0 percent.
  10. 10. The integrated continuous process of spraying, drying, cooling and detecting the graphite slurry for the PAFC separator of the phosphoric acid fuel cell according to claim 4, wherein in the step 4, the uneven spraying or the missing spraying defect is identified by a visual detection system, and when the missing spraying area is identified to be more than 0.5 square millimeter or the local stacking height deviation is identified to be more than 10 micrometers, the defective product is judged and removed.

Description

Integrated continuous process for spraying, drying, cooling and detecting graphite slurry of PAFC separator of phosphoric acid fuel cell Technical Field The invention relates to the technical field of energy power, in particular to a continuous process integrating spraying, drying, cooling and detecting of graphite slurry of a PAFC separator of a phosphoric acid fuel cell. Background Phosphoric acid fuel cells act as a highly efficient energy conversion device, with the internal separator assembly serving the functions of conducting electricity and physical support. In order to increase the conductivity of the separator surface and to enhance its corrosion resistance in high temperature and strong acid environments, it is often necessary to prepare a uniform conductive graphite coating on the substrate surface, which coating physical consistency and chemical stability directly affect the operating life of the stack. In the current industrial production, the preparation of the separator graphite coating mostly adopts a sectional or intermittent operation flow. The specific technological process generally comprises discrete links of spraying, drying, cooling, end detection and the like, and materials are physically transported between stations. The spraying link mainly depends on preset fixed parameters to operate, and the drying and cooling processes are completed in an open or semi-closed environment. The quality detection means is usually arranged at the end of the production line, and the weight increment and the surface defects of the finished product are subjected to spot check or full check by manual or automatic equipment. The prior art has obvious technical consistency guarantee difficult problems in the long-term operation process. Because the spraying link and the detection link are in mutually independent physical procedures, the system lacks an effective online data feedback mechanism, and the spraying parameters at the front end cannot be corrected in real time according to the detected coating quantity deviation. When the viscosity of the slurry is subjected to fluctuation caused by environmental interference or the system drift is caused by mechanical abrasion of the nozzle, the thickness of the coating often continuously deviates, the production process is in an open loop state, and accurate self-compensation and control of the coating quality are difficult to realize in continuous operation. Disclosure of Invention Aiming at the defects of the prior art, the invention provides an integrated continuous process of spraying, drying, cooling and detecting graphite slurry of a PAFC separator of a phosphoric acid fuel cell, and solves the problems mentioned in the background 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 graphite slurry for a PAFC separator of a phosphoric acid fuel cell, which adopts the following technical scheme: the graphite slurry for the PAFC separator of the phosphoric acid fuel cell comprises the following raw materials in parts by weight: 60-80 parts of flake graphite, 10-20 parts of fluorine modified phenolic resin, 1-5 parts of polytetrafluoroethylene emulsion, 1-5 parts of dispersing agent and 100-150 parts of diluting solvent. By adopting the technical scheme, the principle and innovation mechanism are as follows: because the fluorine modified phenolic resin with a specific proportion is adopted as the core bonding component, the high bond energy is utilized Key (about)) The shielding effect formed on the molecular skeleton makes the coating layer onThe high-temperature phosphoric acid environment has extremely high chemical inertness and can prevent the acid liquor from corroding and degrading the resin main chain. Meanwhile, the hydrophobic effect of polytetrafluoroethylene emulsion and the high conductivity of crystalline flake graphite are matched, so that the electrochemical performance and the stability of the physical structure of the separator under long-term operation are ensured. Preferably, the fluorine modified phenolic resin is a random copolymer polymer compound with number average molecular weight3500-4500 G/mol, molecular weight distribution index1.2-1.5, Glass transition temperature82-88 Degrees celsius. By adopting the technical scheme: The synthesis process follows the following reaction mechanism: and in the primary polycondensation stage, phenol and formaldehyde undergo methylolation reaction under the catalysis of oxalic acid to generate the linear phenolic oligomer bridged by methylene. And in the fluorination modification stage, 1H, 2H-perfluoro-1-octanol is dropwise added into a reaction system, hydroxyl of the fluoroalcohol and hydroxymethyl at the tail end of the oligomer are subjected to etherification reaction, and a perfluorooctyl side chain is grafted on a phenolic backbone. The linear structure with medium polymerization degree ensures