Abstract: Disclosed is a solid oxide fuel cell system with enhanced thermal efficiency. Accordingly, provided is a solid oxide fuel cell system with enhanced thermal efficiency, which is capable of heating and using fuel, air, or water supplied to a hot box at a room temperature by a heat exchanger in the hot box and minimizing heat discharged to the outside of the hot box.

Abstract: Disclosed is a boiler system using a fuel cell including a boiler installed in a home, a building, or the like, a fuel cell for generating electricity and reaction heat by electrochemical reaction between a fuel and oxygen, a storage tank for recovering and storing the reaction heat generated by the fuel cell with a fluid, a room heating line buried beneath a room floor of the home, the building, or the like, a warm water line connected to supply warm water to a washroom or a kitchen of the home or the building through the boiler or the storage tank when water is supplied thereto from the outside, and a suction and exhaust integrated pipe having at least two of at least one first exhaust line, at least one first suction line of the boiler, at least one second exhaust line, and at least one second suction line of the fuel cell connected thereto to be used in common.