WATER RECOVERY IN A FUEL CELL SYSTEM

A fuel cell system comprises a fuel cell stack with a cathode exhaust outlet coupled to a cathode exhaust conduit. A condenser is provided in the cathode exhaust conduit for extracting water from a cathode exhaust stream in the cathode exhaust conduit. A compressor is disposed in the cathode exhaust conduit between the cathode exhaust outlet and the condenser and an expander is disposed downstream of the condenser for recovering energy from the condenser exhaust stream. By providing compressor and expander stages on either side of the condenser, the condenser performance can be enhanced by higher pressure operation independent of the fuel cell pressure. The parasitic load of this pressurised operation of the condenser is reduced by recovering the energy from the exhaust stream.