Patent ID: 7223487
Filing Date: 2007-05-29
Classification: H01M,Y02E

Abstract:
1. A fuel cell system comprising: a fuel cell to generate electric power, having a fuel electrode to which a fuel gas is supplied and an air electrode to which air is supplied; a compressor for compressing air and supplying the compressed air to the air electrode; a cooling water system for cooling the fuel cell with cooling water circulating therethrough, the cooling water system including a radiator for releasing heat of the cooling water, and a liquid-gas heat exchanger for cooling the compressed air to be supplied to the air electrode with the cooling water: a gas-gas heat exchanger which cools air discharged from the compressor to be supplied to the liquid-gas heat exchanger with air discharged from the air electrode; an expander for expanding air discharged from the gas-gas heat exchanger to recover energy therefrom; a compressor driving motor for driving rotation of the compressor; a generator being driven by rotation of the expander to generate electric power; and a controller for distributing electric power generated by the generator and the fuel cell to the compressor driving motor and a load; wherein the rotation of the expander is independent of the rotation of the compressor.