A fuel cell and a boiler are coupled in such a manner that the water used to capture excess heat generated by the fuel cell is used for boiler feedwater heating. In one embodiment, steam generated by the boiler is used in an operation that converts the steam to condensate, and the condensate is returned...http://www.google.fr/patents/US5335628?utm_source=gb-gplus-shareBrevet US5335628 - Integrated boiler/fuel cell system
