Heat exchange device and fuel cell system

The utility model discloses a heat exchange device and a fuel cell system, and belongs to the field of fuel cells. The fuel cell system comprises an electric pile and a heat exchange device, the heat exchange device comprises a cold flow pipeline and a hot flow pipeline, the middle of the cold flow pipeline is sleeved with the hot flow pipeline, and the flowing direction of cold fluid in the cold flow pipeline is opposite to that of hot fluid in the hot flow pipeline. High-temperature cooling liquid from the galvanic pile enters the hot flow pipeline and finally flows back to the galvanic pile, and a gaseous mixture from the galvanic pile and fresh hydrogen form hydrogen mixed gas which enters the cold flow pipeline, so that the high-temperature cooling liquid and the hydrogen mixed gas fully exchange heat in the heat exchange device. The temperature of the hydrogen mixed gas before entering the stack is close to the proper temperature of a fuel cell system, and meanwhile, the risk that the hydrogen mixed gas