| 摘要 |
The object is to suppress degradation of the durability of an electrolyte membrane caused by deformation by expansion and contraction of the electrolyte membrane. A controller 150 calculates a humidity P of an electrolyte membrane 112 based on a cell resistance value (step S11) and determines whether the humidity P of the electrolyte membrane 112 is less than a humidity threshold A (step S12). When the humidity P is less than the humidity threshold A, the controller 150 determines that a dimensional change rate of the electrolyte membrane is not greater than a predetermined value and performs a process of increasing the humidity of the electrolyte membrane 112 (step S13). The predetermined value is a dimensional change rate that is unlikely to have damage by drying stress. This enables the electrolyte membrane 112 to be humidified before the electrolyte membrane 112 is excessively dried and thereby suppresses tensile stress from being applied to the electrolyte membrane 112 by drying of the electrolyte membrane 112. Accordingly this suppresses cracking and thinning of the electrolyte membrane 112 and improves the durability of the electrolyte membrane 112. |
