Patent ID: 8349506
Filing Date: 2013-01-08
Classification: H01M,Y02E

Abstract:
1. A fuel cell system comprising: a storage portion that stores liquid hydrogen; a fuel cell that uses hydrogen gas as fuel gas; a fuel supply portion that provides hydrogen gas to an anode of the fuel cell, the hydrogen gas being generated caused by a vaporization of the liquid hydrogen stored in the storage portion; a hydrogen circulation system in fluid communication with the anode of the fuel cell and the fuel supply portion, and which comprises a hydrogen pump that circulates the hydrogen in the hydrogen circulation system; a boil-off gas supply portion, in fluid communication with both the storage portion and the circulation system, that provides boil-off gas generated in the storage portion to the hydrogen circulation system, a pressure detection portion that detects a pressure in the hydrogen circulation system; a determination portion that determines whether the boil-off gas is provided to the hydrogen circulation system when a value detected by the pressure detection portion is more than a threshold value; and a hydrogen-circulation-amount controller that reduces a rotation frequency of the hydrogen pump when the determination portion determines that the boil-off gas is provided to the hydrogen circulation system; wherein the boil-off gas supply portion is in fluid communication with the hydrogen circulation system at a point along the hydrogen circulation system upstream of an inlet of the anode of the fuel cell, and wherein the storage portion includes a storage tank having two separate supply paths: the fuel supply portion and the boil-off gas supply portion.