Patent ID: 7968242
Filing Date: 2011-06-28
Classification: H01M,Y02E

Abstract:
1. An onboard fuel cell system comprising: a fuel cell which may be supplied with hydrogen gas and oxidative gas, which is able to generate electric power using the hydrogen gas and the oxidative gas, and which is able to discharge hydrogen-off gas and oxygen-off gas that have been consumed; a first flow passage which leads to a hydrogen-off gas exhaust port of the fuel cell and through which the discharged hydrogen-off gas can flow; a second flow passage which leads to an oxygen-off gas exhaust port of the fuel cell and through which the discharged oxygen-off gas can flow; a mixing portion which is connected to receive the discharged hydrogen-off gas and the discharged oxygen-off gas from the first and second flow passages respectively and in which the oxygen-off gas may be mixed with the hydrogen-off gas; a third flow passage which leads from the mixing portion and through which the mixed gases can flow so that the hydrogen-off gas is discharged to the atmosphere; a valve which is disposed in the first flow passage; and a control portion programmed to control the valve to open and close the valve to allow or block flow of the hydrogen-off gas to the mixing portion and thereby control flow of hydrogen-off gas which is mixed with the oxygen-off gas in the mixing portion; wherein the control portion is programmed to control feeding of hydrogen-off gas to the mixing portion so that a proportion of hydrogen-off gas fed to the mixing portion is sufficiently diluted in the mixing portion such that a mixture of the hydrogen-off gas and the oxygen-off gas in the mixing portion avoids ignition, the mixture subsequently exiting the mixing portion.