| 摘要 |
A method of operating a fuel cell system 100 comprising a fuel cell stack 102 with a reactant flow path having an inlet 106, 110 and an outlet 108, 112, wherein the reactant flow path forms part of a water circuit of the fuel cell system, is disclosed. The method comprises (a) determining a liquid level in the water circuit; (b) comparing a value related to the liquid level with a threshold; (c) controlling one or more parameters of the fuel cell system in accordance with the comparison in order to set a rate of water retrieval from the outlet 108; and (d) directly injecting water into the inlet 106. Preferably, the water level is measured within a water tank 150, using a liquid level sensor 152, a temperature sensor 153, and/or conductivity sensor 155. The parameter(s) to be controlled may increase or decrease the rate of water retrieval from the outlet 108 depending on the water level, and may comprise controlling (i) temperature through or at the outlet of the stack, e.g. using a heat exchanger 128, (ii) back pressure in the reactant flow path, (iii) oxidant flow rate at the inlet, and/or (iv) current or power drawn from the stack. The water circuit may be a water cooling circuit, e.g. in an evaporatively cooled fuel cell (ECFC) or liquid cooled fuel cell (LCFC) system. A fuel cell system for carrying out the method is also disclosed. |
