Patent ID: 9653740
Date: 2017-05-16
CPC Classifications: H01M,Y02E

Claim:
1. A fuel cell system comprising: a fuel cell; a fuel supply source that supplies a fuel gas to the fuel cell; a supply passage through which the fuel gas supplied from the fuel supply source flows to the fuel cell; a circulation passage through which the fuel gas partially discharged from the fuel cell flows to the supply passage; a gas-liquid separator that is arranged in the circulation passage and that stores and separates water from the fuel gas partially discharged from the fuel cell; a discharge passage that is connected to the gas-liquid separator, discharges stored water in the gas-liquid separator to an outside, and partially discharges the fuel gas partially discharged from the fuel cell to the outside; a discharge valve that is arranged in the discharge passage; a differential pressure detecting portion that detects a differential pressure between a downstream side of the discharge valve and one of the supply passage, the circulation passage, the gas-liquid separator, and an upstream side of the discharge valve in the discharge passage; and a control unit that estimates a flow rate of the fuel gas partially discharged from the fuel cell partially discharged by opening the discharge valve, wherein the discharge valve includes: the control unit estimates the flow rate of the fuel gas, based on the differential pressure while the discharge valve is opened, and based on a percentage of the fuel gas to a cross sectional area of the discharge outlet, except for a percentage of the stored water to the cross sectional area, while the discharge valve is opened.