Fuel cell system and liquid discharging method for the same

Abstract

To provide a fuel cell system capable of reliably and rapidly discharging liquid in a fuel cell stack to the outside. The fuel cell system includes a discharge passage (76) capable of discharging at least liquid in the fuel cell stack (20), and is characterized in that: when the fuel cell stack (20) is started, a specific amount of fuel is supplied to the fuel cell stack (20) The normal operation of the battery pack (20) is supplied with a higher velocity of reactant gas or a large amount of reactant gas. By supplying a high-velocity or large amount of reaction gas before starting, the residual liquid in the fuel cell stack 20 can be blown off and reliably and quickly discharged to the outside. In addition, the discharge can be made easier by providing the reservoir (30) in the discharge passage (76), or by setting the internal pressure of the fuel cell stack to a negative pressure state when the fuel cell stack (20) is started.

Description

technical field [0001] The present invention relates to a fuel cell system, in particular to a fuel cell system capable of efficiently discharging liquid remaining in a fuel cell stack when the fuel cell is started, and a liquid discharge method thereof. Background technique [0002] Fuel cells are attracting attention as environmentally friendly and clean power sources. A fuel cell generates electricity through an electrochemical reaction using a fuel gas such as hydrogen and an oxidizing gas such as air. Since generated water (water vapor) is generated by the electrochemical reaction between the fuel gas and the oxidizing gas, the generated water should be properly discharged during the operation of the fuel cell. [0003] However, when the fuel cell is restarted after the operation of the fuel cell is stopped, produced water and dew condensation water remain in the fuel cell stack, and it is difficult to restart smoothly if the fuel cell remains as it is. As a method of...

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Problems solved by technology

[0003] However, when the fuel cell is restarted after the operation of the fuel cell is stopped, generated water and dew condensation water remain in the fuel cell stack, and it is difficult to restart smoothly if it is left as it is.

As a method of removing the generated water and dew condensation water, it is conceivable to operate the circulation pump of the fuel gas circulation system at a high rotation speed, but there is a problem of deterioration of noise.

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