Young Soo Joung, Hye Jung Cho, Jung Kurn Park, In Seob Song, Seong Kee Yoon, China Patent: CN101807706
A fuel cell system includes: a fuel cell stack for generating electrical energy by reacting oxidant and mixed fuel, and for discharging non-reacted fuel, oxidant, moisture, and carbon dioxide; a mixer for preparing the mixed fuel by mixing at least a portion of the non-reacted fuel, oxidant and moisture with concentrated fuel and for supplying the mixed fuel to the fuel cell stack; a fuel supply unit for supplying the concentrated fuel to the mixer; an oxidant supply unit for supplying the oxidant to the fuel cell stack; a first heat exchanger between an outlet of the fuel cell stack and the mixer; and a second heat exchanger between the mixer and an inlet of the fuel cell stack.
https://www.google.com/patents/US20100209788?dq=EP2226883+A1&ei=UTt4UqLSKuHJsQTI-4HwBA&cl=en