Patent ID: 6979509

Claim:
A freeze tolerant fuel cell power plant ( 10 ) for generating an electrical current from hydrogen containing reducing fluid fuel and oxygen containing oxidant reactant streams, the plant comprising: a. at least one fuel cell ( 12 ) having a proton exchange membrane electrolyte ( 19 ); b. a coolant loop ( 42 ) including a porous water transport plate ( 44 ) secured in heat and mass exchange relationship within the fuel cell ( 12 ), a coolant circulating means ( 46 ) secured to a coolant passage ( 68 ) in fluid communication with the porous water transport plate ( 44 ) for circulating a coolant through the plate ( 44 ) and for transferring water into or out of the plate ( 44 ) with the coolant, coolant heat exchanger ( 52 ) means secured to the coolant passage ( 68 ) for removing heat from the coolant, an accumulator ( 66 ) means secured in fluid communication with the coolant passage ( 68 ) for storing the coolant and water; and, c. wherein the coolant is a two-component mixed coolant circulating through the coolant loop ( 42 ), the two-component mixed coolant consisting of a water immiscible fluid component and a water component.