| 摘要 |
Fuel cell/electrolyser stacks 1 are housed in a chamber 101 having a manifold system 102 for connection to fuel outlets (6), oxidant outlets (7), coolant inlet/outlets (8,9) and electrical connections, and electrical connection system 103. Void space 104 is filled with an oxidant gas. Each stack is annular and contains a central aperture 403 formed by stacking a number of membrane electrode assemblies (MEAs) bracketed by field flow plates 2. Fuel enters the flow field plate 2 via aperture 403, passes through inlet 404 to humidification section 407, through flow field 408 to outlet 409 via drain 405. On the reverse of the plate, oxidant enters through the outer edge (402), to inner drain 407 and out through aperture 407, Adjacent apertures 407 form a continuous channel leading to oxidant outlet 7. Flow plate 2 also includes a coolant channel (not shown) which serves to humidify the incoming fuel in section 407 via a porous membrane. Adjacent flow plates have a sealing ring between them mounted in a groove (not shown). In use the oxidant filled chamber exerts a force on the stack that at least partially counteracts the force generated by the gases within the stack. The fuel and oxidant flows are also countercurrent over the MEA which maintains a more even pressure over the electrolyte membrane. Finally the fuel and oxidant pressures may be adjusted such that each flow plate is urged towards its neighbour to help maintain a positive seal. The system may be reversed, ie the surrounding chamber contains fuel, whilst oxidant enters through the central aperture. |
