An estimating unit for a fuel cell system for estimating residual water content during standstill

摘要

An object of the invention is to provide a fuel cell system capable of improving accuracy of water content estimation during a standstill. A fuel cell system includes a fuel cell having a plurality of single cells laminated together and an estimating unit for estimating residual water content distributions in a fuel gas flow channel and an oxidation gas flow channel and a moisture content distribution in an electrolyte membrane in a cell plane of each single cell while taking into consideration water transfer that occurs between an anode electrode and a cathode electrode via the electrolyte membrane. The estimating unit estimates a residual water content of the fuel gas flow channel during a standstill from a shutdown to a restart of the fuel cell system based on temperature information on each single cell acquired during the standstill. In addition, the fuel cell system is capable of executing a scavenging process on the fuel gas flow channel when the residual water content of the fuel gas flow channel estimated during the standstill exceeds a predetermined threshold.