A related art of this type of fuel cell system is disclosed in JP 2005-201822 A. In JP 2005-201822 A, two openable/closable shut valves are provided in a fuel gas supply path for connecting a fuel tank and the anode side of a fuel cell, and a regulating valve is provided between the two shut valves. When generating electricity from the fuel cell, the two shut valves are opened to let the fuel gas flow from the fuel tank to the fuel cell. The pressure of the fuel gas is regulated by the regulating valve before being supplied to the fuel cell. On the other hand, when stopping the generation of electricity from the fuel cell, the two shut valves are closed to stop supply of the fuel gas to the fuel cell. Accordingly, sealability of fuel gas when stopping generation of electricity from the fuel cell is improved.
A fuel cell system is also disclosed in JP 2005-11703 A, JP 2004-170321 A, and JP 8-329965 A.
In JP 2005-201822 A, two shut valves are provided in the fuel gas supply path for connecting the fuel tank with the anode side of the fuel cell so as to improve sealability. In this case, performance required of each shut valve depends on where each shut valve is disposed. For example, a shut valve disposed on an upstream side (fuel tank side) of the fuel gas flow is required to ensure sealability against high pressure of fuel gas. On the other hand, a shut valve disposed on the downstream side (fuel cell side) of the fuel gas flow is required to ensure sealability against low pressure of fuel gas. Conventionally, common shut valves having the sealability required in all locations of disposal are arranged in series. However, as a result of higher pressure of supplied fuel gas (higher pressure of fuel gas storage means), the pressure range and temperature range, etc. required of shut valves became broader. Consequently, it became necessary to use rare materials as materials for the shut valve seal member, and the size of components became larger due to the provision of redundancy, which resulted in a complicated shut valve configuration.
The present invention provides a fuel cell system, a fuel cell valve system, and fuel gas supply device, using a simpler shut valve without deteriorating the sealability of the entire system.