US 7,462,414 B2
Fuel cell system
Yuichi Sakajo, Toyohashi (Japan); Naoto Hotta, Aichi-gun (Japan); and Ken Matsunaga, Kariya (Japan)
Assigned to Denso Corporation, Kariya (Japan)
Filed on Jul. 05, 2007, as Appl. No. 11/822,440.
Claims priority of application No. 2006-200585 (JP), filed on Jul. 24, 2006.
Prior Publication US 2008/0145731 A1, Jun. 19, 2008
Int. Cl. H01M 8/04 (2006.01)
U.S. Cl. 429—26  [429/25] 13 Claims
OG exemplary drawing
 
1. A fuel cell system comprising:
a fuel cell for generating electrical power by performing electrochemical reaction of combining oxidizing agent gas and fuel gas;
an oxidizing agent gas exhaust passage through which non-reacted residual oxidizing agent gas in the oxidizing agent gas supplied to the fuel cell passes to the outside of the fuel cell system;
a refrigerant circulation passage through which refrigerant is circulated;
a refrigerant compressor for compressing the refrigerant and sending the compressed refrigerant to the refrigerant circulation passage;
a refrigerant-outdoor air heat exchanger for performing heat exchange between an outdoor air and the refrigerant discharged from the refrigerant compressor;
an oxidizing agent gas-refrigerant heat exchanger for performing heat exchange between the oxidizing agent gas passing through the oxidizing agent gas exhaust passage and the refrigerant passing through the refrigerant circulation passage;
a primary pressure reducing valve for reducing a pressure of the refrigerant, which is disposed between the refrigerant compressor and the oxidizing agent gas-refrigerant heat exchanger; and
a secondary pressure reducing valve for reducing a pressure of the refrigerant, which is disposed between the oxidizing agent gas-refrigerant heat exchanger and the refrigerant-outdoor air heat exchanger,
wherein during the heat transfer between the oxidizing agent gas and the refrigerant by the oxidizing agent gas-refrigerant heat exchanger, the primary pressure reducing valve reduces the pressure of the refrigerant so that a temperature of the refrigerant becomes not less than a specified temperature at which water component contained in the oxidizing agent gas does not freeze.