COGENERATION SYSTEM FOR A FUEL CELL AND METHOD THEREOF

A cogeneration system for a fuel cell is provided to perform initial driving using exhaust gas generated from the system without using a separate preheater. A cogeneration system for a fuel cell includes: a fuel supply unit which supplies a fuel gas needed for generating electricity; a gas-liquid supply unit(51) which supplies water and oxidant gas through different routes; a reformer(20) which reforms the fuel supplied from the fuel supply unit and the water supplied from the gas-liquid supply unit to produce a hydrogen gas; a fuel cell stack(30) which exposes the oxidant gas supplied from the gas-liquid supply unit and the hydrogen gas supplied from the reformer to electrodes to generate electric energy; and an exhaust gas recovery unit which recovers and heats the exhaust gas generated from the fuel cell stack, senses the remaining hydrogen gas contained in the exhaust gas, and selectively provides a heat source needed for the initial driving or normal driving of the system.