| 摘要 |
PURPOSE:To obtain a heat-exchanger suitable for phosphoric acid fuel cell by applying water-repellent agent onto the endface of carbon cooling board. CONSTITUTION:Cooling tubes 3 are burried in the grooves 2 made in carbon cooling board 1 in heat-exchanger. The cooling tube 3 is a steel pipe coated with tetra-ethylene fluoride resin (PTFE). The gap between the groove 2 and the cooling tube 3 is filled with filler 4 composed of mixture of graphite powder and PTFE. While fluororesin water-repellent agent is applied onto the sideface and the circumferential section of upper and lower faces of cooling board 1 by 50mm to form a water-repellent layer 5. Such carbon cooling board 1 is inserted through a glassy carbon separator 6 having excellent phosphoric acid resistance between unit cells 7a, 7b. In such a manner, the carbon cooling board 1 is assembled as required into the laminated cell 8. With such arrangement, phosphoric acid mist existing in reaction gas is blocked by water-repellent layer 5 and carbon separator 6 resulting in improvement of phosphoric acid resistance of carbon cooling board. |
