초록 ▼

Fuel Cell stack coolant water is processed by moving the two-phase water/steam coolant exhaust through a steam separator wherein the water phase is separated from the steam phase. The water phase is then moved through a heat exchanger where its temperature is lowered to a subcooled level which is be

Fuel Cell stack coolant water is processed by moving the two-phase water/steam coolant exhaust through a steam separator wherein the water phase is separated from the steam phase. The water phase is then moved through a heat exchanger where its temperature is lowered to a subcooled level which is below the coolant operating temperature in the stack. A flow control valve is associated with the coolant heat exchanger to regulate water flow through and/or around the heat exchanger depending on the temperature of the water which leaves the steam separator. By subcooling the coolant before it reenters the stack, a lessening of electrolyte loss through evaporation is achieved. By eliminating steam condensation as a form of system heat rejection, system engineering is simplified and construction costs are lowered.

대표청구항 ▼

A fuel cell stack cooling using a water coolant comprising: (a) coolant passages in the stack, said coolant passages having an inlet end and an outlet end for receiving water and discharging a water/steam mixture respectively, said coolant passages in counterflow relationship to oxidation gas flowin

A fuel cell stack cooling using a water coolant comprising: (a) coolant passages in the stack, said coolant passages having an inlet end and an outlet end for receiving water and discharging a water/steam mixture respectively, said coolant passages in counterflow relationship to oxidation gas flowing through the stack; (b) a steam separator; (c) a first conduit at said coolant passage outlet end for conveying the water/steam mixture from said stack to said steam separator, wherein the water and steam are separated from each other; (d) a second conduit conveying steam from said steam separator to a catalytic fuel reformer; (e) a heat exchanger for removing heat from water passing therethrough; (f) a third conduit at said steam separator for conveying water from said steam separator to said heat exchanger operable to lower the temperature of the water; (g) a fourth conduit at said heat exchanger for conveying water from said heat exchanger to said inlet end of said coolant passages thereby forming a coolant loop; (h) a pump for circulating coolant through said loop; (i) modulating means for modulating the heat removed by said heat exchanger; (j) sensor means for sensing a measure of the temperature of the water in the steam separator; and (k) control means responsive to said sensor means for varying said modulation means to maintain said measure of temperature at a preselected value.