Fuel cell system and method for removing residual fuel gas

Abstract

A fuel battery system capable of quickly consuming residual hydrogen gas even if a restriction is imposed to surplus power consuming means. While the system is not in operation, a fuel battery (10) is allowed to generate power by using the surplus fuel gas to charge a secondary battery (41), and non-storable surplus power is consumed by consuming means (22, 33, 13). When the surplus power generated by the fuel battery is consumed by the consuming means, the restricted state of the system is detected, and the power generated by the fuel battery is varied depending on the detected restricted state.

Description

technical field [0001] The present invention relates to a fuel cell system, and more particularly to an improvement in a fuel cell system that consumes excess fuel gas remaining in a fuel cell and gas piping when operation is stopped by generating electricity. Background technique [0002] Conventionally, a fuel cell system has been developed that generates electricity by a fuel cell and consumes hydrogen gas remaining in piping when the operation is stopped. For example, Japanese Unexamined Patent Publication No. 2001-229951 discloses a mobile fuel cell system that can switch between charging the battery and discharging the electric power generated from residual hydrogen gas to the discharge resistor circuit according to the state of charge of the battery. [0003] Specifically, when the remaining power is at a voltage that can charge the battery and the battery is not overcharged, the remaining power is charged into the battery; when the battery is fully charged or the rem...

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Problems solved by technology

[0005] However, in the above-mentioned conventional technology, since the value of the surplus power generated by the fuel cell is maintained at a constant value, problems may arise depending on the state of the components that consume the surplus power.

For example, when the power consuming device is a motor, the motor may not be able to consume the remaining power that cannot be charged to the storage battery due to restrictions such as NV requirements on the motor.

In such a case, the total amount of electric power that can be charged to the battery and consumed by the electric motor is not constant, and as a result, the electric power generated decreases, and the remaining hydrogen gas cannot be disposed of in a short time.

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