Fuel cell system

Abstract

The fuel system includes a fuel cell capable of generating electric power to be supplied to electric loads, a storage battery charged by the fuel cell and capable of supplying electric power stored therein to the electric loads, a first gas-supply path through which the oxidizing gas to be supplied to the fuel cell passes, a compressor for compressing the oxidizing gas passing through the first gas-supply path, a second gas-supply path branching from the first gas-supply path, through which the oxidizing gas discharged from the compressor passes toward the storage battery, a flow-switch valve operating to switch a flow direction of the oxidizing gas between a first direction through the first gas-supply path toward the fuel cell and a second direction through the second gas-supply path toward the storage battery, and a control unit controlling a flow direction switching operation of the flow-switch valve.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings:

FIG. 1 is a diagram showing an overall structure of a fuel cell system according to an embodiment of the invention, which is mounted on an electric vehicle (fuel cell vehicle) that runs on the electric power supplied from this fuel cell system;

FIG. 2 is a diagram explaining signals inputted to and outputted from a control unit included in the fuel cell system shown in FIG. 1; and

FIG. 3 is a flowchart showing flow of a temperature control performed by the control unit shown in FIG. 2.

Claims

1. A fuel system comprising: a fuel cell capable of generating electric power by electrochemical reaction between an oxidizing gas and a reducing gas, and supplying generated electric power to electric loads;a storage battery electrically connected to said fuel cell so as to be charged by said fuel cell, and capable of supplying electric power stored therein to said electric loads;a first gas-supply path through which said oxidizing gas to be supplied to said fuel cell passes;a compressor provided in said first gas-supply path to compress said oxidizing gas passing through said first gas-supply path;a second gas-supply path branching from said first gas-supply path, through which said oxidizing gas discharged from said compressor passes toward said storage battery;a flow-switch valve operating to switch a flow direction of said oxidizing gas between a first direction through said first gas-supply path toward said fuel cell and a second direction through said second gas-supply path toward said storage battery; anda control unit controlling a flow direction switching operation of said flow-switch valve.

2. The fuel cell system according to claim 1, wherein said flow-switch valve is configured to individually adjust a flow rate of said oxidizing gas flowing in said first direction and said oxidizing gas flowing in said second direction.

3. The fuel cell system according to claim 1, further comprising a temperature sensor for detecting a temperature of said storage battery, said control unit controlling said flow-direction switching operation of said flow-switch valve on the basis of said temperature of said storage battery detected by said temperature sensor.

4. The fuel cell system according to claim 2, further comprising a temperature sensor for detecting a temperature of said storage battery, said control unit controlling said flow-direction switching operation of said flow-switch valve on the basis of said temperature of said storage battery detected by said temperature sensor.

5. The fuel cell system according to claim 1, further comprising a first temperature sensor for detecting a temperature of said storage battery, and a second temperature sensor for detecting a temperature of said oxidizing gas discharged from said compressor, said control unit controlling said flow-direction switching operation of said flow-switch valve on the basis of said temperature of said storage battery detected by said first temperature sensor, and said temperature of said oxidizing gas detected by said second temperature sensor.

6. The fuel cell system according to claim 2, further comprising a first temperature sensor for detecting a temperature of said storage battery, and a second temperature sensor for detecting a temperature of said oxidizing gas discharged from said compressor, said control unit controlling said flow-direction switching operation of said flow-switch valve on the basis of said temperature of said storage battery detected by said first temperature sensor, and said temperature of said oxidizing gas detected by said second temperature sensor.

7. The fuel cell system according to claim 1, further comprising a heat exchanger provided in said first gas-supply path for cooling said oxidizing gas discharged from said compressor, said second gas-supply path branching from said first gas-supply path in the upstream of said heat exchanger.

8. The fuel cell system according to claim 7, further comprising a third gas-supply path through which said oxidizing gas supplied to said storage battery passes to return to said first gas-supply path in the downstream of said heat exchanger.