Patent ID: 6602624
Filing Date: 2003-08-05
Classification: B60L,H01M,Y02E,Y02T

Abstract:
In a fuel cell system having a fuel processor generating reformate to a fuel cell stack, a combustor generating heat for the fuel processor upon combusting a fuel from one of a variable fuel injector and excess fuel from the fuel cell stack, and a heat dump valve coupled to the combustor for diverting excess heat from the combustor, the method comprising the steps of:determining a temperature difference between the actual operating temperature of the fuel processor and the desired operating temperature of the fuel processor at a given fuel cell stack load; if the actual temperature of the fuel processor is less than the desired temperature of the fuel processor, predicting the amount of heat required by the fuel processor based on the determined temperature difference; generating a command to the fuel injector to supply fuel to the combustor to generate the required amount of heat only if the heat dump valve is closed; if the actual temperature of the fuel processor is greater than the desired temperature of the fuel processor, determining the amount of heat that must be diverted from the combustor prior to input to the fuel processor to lower the actual temperature of the fuel processor to the desired temperature; determining the position of the heat dump valve orifice to divert the determined amount of heat; and generating a command to the heat dump valve orifice to divert the desired amount of heat only if the fuel injector is closed.