FREEZE START-UP METHOD FOR FUEL CELL SYSTEM

摘要

Methods are disclosed for starting up a fuel cell system from subzero temperatures using the latent heat of crystallization available in a water supply maintained at above freezing temperature. During start-up, a water spray subsystem is used to spray water from the supply onto a heat exchange surface in a heat exchange element through which coolant from a fuel cell stack coolant circuit is circulating. The water freezes onto the heat exchange surface and the heat of crystallization is exchanged with the circulating coolant across the heat exchange surface, thus warming the coolant.

主权项

1. A method for starting up a fuel cell system from a temperature below freezing, the fuel cell system comprising a fuel cell stack; a coolant circuit configured to circulate coolant through the fuel cell stack; a heat exchange element in the coolant circuit wherein the heat exchange element comprises a heat exchange surface and coolant flows on one side of the heat exchange surface; a container comprising a supply of water; a water spray subsystem configured to obtain water from the water supply in the container and to spray the water onto the other side of the heat exchange surface, and the method comprising:
maintaining the supply of water at above freezing temperature prior to starting up; circulating coolant through the coolant circuit, the fuel cell stack, and the heat exchange element; obtaining water from the water supply in the container; and spraying the water onto the other side of the heat exchange surface while the fuel cell system is at a temperature below freezing.