| 摘要 |
Water flow field inlet manifolds ( 33, 37 ) are disposed at the fuel cell stack ( 11 ) base. Water flow field outlet manifolds ( 34, 38 ) are located at the fuel cell stack top. Outlet and inlet manifolds are interconnected ( 41-43, 47, 49, 50 ) so gas bubbles leaking through the porous water transport plate cause flow by natural convection, with no mechanical water pump. Variation in water level within a standpipe ( 58 ) controls ( 56, 60, 62, 63 ) the temperature or flow of coolant. In another embodiment, the water is not circulated, but gas and excess water are vented from the water outlet manifolds. Water channels ( 70 ) may be vertical. A hydrophobic region ( 80 ) provides gas leakage to ensure bubble pumping of water. An external heat exchanger ( 77 ) maximizes water density differential for convective flow. |
