FUEL BATTERY SYSTEM AND METHOD FOR CALCULATING CIRCULATION RATIO IN THE FUEL BATTERY SYSTEM

摘要

This invention provides a fuel battery system, which, during the operation of the system, can suppress freezing at a part where a supply gas meets a circulation gas, and a method for calculating the circulation ratio of the system. In the fuel battery system, a circulation gas discharged from a fuel battery is allowed to meet a supply gas from a gas supply source and is then supplied into a fuel battery. The ratio of the flow rate of the circulation gas relative to the flow rate of the supply gas is set while taking into consideration the condensation latent heat of steam in the circulation gas. The ratio of the flow rate of the circulation gas to the flow rate of the supply gas can be set by taking the condensation latent heat into consideration in the calculation of heat balance at the meeting part.