US Patent 9634337 Freeze-resistant fuel cell condensers

Cathode exhaust of an evaporatively cooled fuel cell stack (50) is condensed in a heat exchanger (12a, 23, 23a) having extended fins (14, 25a) or tubes (24, 24a) to prevent pooling of condensate, and/or having the entire exit surface of the condenser rendered hydrophilic with wicking (32) to conduct water away. The cathode exhaust flow paths may be vertical or horizontal, they may be partly or totally rendered hydrophilic, and if so, in liquid communication with hydrophilic end surfaces of the condenser, and the condensers (49) may be tilted away from a normal orientation with respect to earth's gravity.