Solid oxide fuel cell systems

According to one embodiment of the present invention a fuel cell system comprises: (i) a plurality of fuel cell packets, each packet comprising at least one fuel inlet, at least one fuel outlet, a frame, and two multi-cell fuel cell devices, the fuel cell devices situated such that an anode side of one fuel cell device faces an anode side of another fuel cell device, and the two fuel cell devices, in combination, at least partially form a fuel chamber connected to the fuel inlet and the fuel outlet; (ii) a plurality of heat exchange packets, each packet comprising at least one oxidant inlet, at least one oxidant outlet, and an internal oxidant chamber connected to the at least one oxidant inlet and the least one oxidant outlet; the heat exchange packets being parallel to and interspersed between the fuel cell packets, such that the heat exchange packets face the fuel cell packets and form, at least in part, a plurality of cathode reaction chambers between the heat exchange packets and the fuel cell packets; (iii) a housing supporting and enclosing the fuel packets and the heat exchange packets; (iv) an oxidant inlet plenum operatively connected to oxidant inlets of the heat exchange packets; (v) an oxidant exhaust plenum operatively connected to the cathode reaction chambers; (vi) an inlet fuel manifold connected to fuel inlets of the fuel cell packets; and (vii) an exhaust fuel manifold connected to the fuel outlets of the fuel cell packets.