Patent ID: 8900770
Filing Date: 2014-12-02
Classification: H01M,Y02E,Y02T

Abstract:
1. A fuel cell system, comprising: a fuel cell stack that generates electrical power by electrochemical reaction of a fuel gas and an oxidant gas; a total generated electrical energy computation device that computes a value pertaining to the total generated electrical energy (Q) as a sum related to the electrical energy generated by said fuel cell stack in a time period from start-up of the fuel cell system until the fuel cell reaches a steady state; and a residual water volume estimation device that is programmed to estimate a residual water volume left in the fuel cell stack based on Q computed by said total generated electrical energy computation device, wherein the estimating comprises: (a) determining whether residual water volume is an increasing function of Q for values of Q below a first pre-determined threshold Q a , for values of Q satisfying Q<Q a ; (b) determining whether residual water volume is an increasing function of Q for values of Q below a second pre-determined threshold Q b , for values of Q satisfying Q a <Q<Q b ; (c) determining whether residual water volume is a decreasing function of Q for values of Q below a third pre-determined threshold Q c , for values of Q satisfying Q b <Q<Q c ; (d) determining whether residual water volume is an essentially constant function of Q for values of Q satisfying Q c <Q; and (e) estimating the residual water volume based on (a)-(d) to: (i) have a negligible value when (a) occurs; (ii) have a value given by a predetermined increasing function of Q when (b) occurs; (iii) have a value given by a predetermined decreasing function of Q when (c) occurs; and (iv) have a value given by a predetermined constant function of Q when (d) occurs.