초록 ▼

The fuel cell stack is a phosphoric acid fuel cell stack which can operate at higher pressures because it does not use steam in the operation of the reformer portion. By being able to operate at higher pressures, the stack displays very low system heat rates and thus higher operating efficiency. The

The fuel cell stack is a phosphoric acid fuel cell stack which can operate at higher pressures because it does not use steam in the operation of the reformer portion. By being able to operate at higher pressures, the stack displays very low system heat rates and thus higher operating efficiency. The higher operating pressure also results in improved fuel cell power density and reduced cost. The stack is cooled by a coolant mixture of air and entrained water droplets comprising cathode exhaust and injected water fog. During the cooling operation, the water droplets in the coolant mixture are vaporized in the cooling passages of the stack. The exhaust from the cooling system after being heated is then delivered to an autothermal reformer where it reacts with a raw fuel reactant to produce hydrogen for operating the fuel cells in the stack. The reformer does not require a separate burner to operate properly.

대표청구항 ▼

A high pressure phosphoric acid fuel cell stack assembly comprising: (a) a stack of fuel cells for producing electricity, said stack including cathode means, anode means, and heat exchange means; (b) means for delivering pressurized air to said cathode means; (c) means for delivering a hydrogen rich

A high pressure phosphoric acid fuel cell stack assembly comprising: (a) a stack of fuel cells for producing electricity, said stack including cathode means, anode means, and heat exchange means; (b) means for delivering pressurized air to said cathode means; (c) means for delivering a hydrogen rich fuel gas to said anode means for electrochemically reacting with oxygen in the pressurized air to produce electricity and water; (d) first conduit means connected to said cathode means for exhausting a mixture of oxygen-depleted air and reaction water from said cathode means; (e) second conduit means connected to said first conduit means for delivering a water fog to said first conduit means for entrainment in said mixture of oxygen-depleted air and reaction water to form a two phase coolant having a gaseous air phase and an entrained water droplet phase; (f) means for circulating said coolant to said heat exchange means to cool said stack solely through vaporization of said water droplet phase in said heat exchange means whereby a mixed gas exhaust of air and water vapor is exhausted from said heat exchange means; and (g) means for heating said mixed gas exhaust and delivering the heated mixed gas exhaust at reformer reaction temperatures to an autothermal reformer in said stack assembly for autothermal reaction with a raw fuel to form said hydrogen rich fuel.