Fuel cell system

A fuel cell system comprising:

• a fuel cell module including a plurality of unit cells for generating electric energy using oxygen of air and hydrogen of reformed fuel gas;
• a first module including:
• a burner to burn unreacted fuel gas and air discharged from the fuel cell module;
• a heat-transfer device placed adjacent to the burner to heat air via heat exchange thereof with flame and hot combusted gas generated from the burner and to supply the heated air to the fuel cell module;
• and
• a water-vapor generator disposed adjacent to the burner to convert water moving therein to water vapor via heat exchange thereof with the hot combusted gas;
• and
• a second module placed adjacent to the first module, wherein the second module is configured to:
• mix fuel supplied from an external fuel supply source and the water vapor supplied from the water-vapor generator with each other to form a mixture;
• perform a water vapor reforming reaction of the mixture;
• and
• supply the reformed fuel gas to the fuel cell module;
• wherein the heat-transfer device includes:
• a first container having a first inner space defined therein, wherein the first container has a bottom having a first opening and a second opening defined therein for exposing the first inner space, wherein the first opening and the second opening are spaced from each other;
• and
• a heat-exchange pipe received in the first inner space and having an inlet connected to an external air supply source and an outlet connected to the fuel cell module,
• wherein the burner includes:
• an outer casing coupled to the bottom of the first container, wherein the outer casing has an open top and has a second inner space communicating with the first inner space through the first opening;
• an inner casing received in the second inner space, wherein the inner casing has a third inner space defined therein, wherein a horizontal cross sectional area of the third inner space increases as the third inner space extends upwards, and wherein the inner casing has an open top, and a side wall having through-holes defined therein communicating the second inner space and the third inner space with each other;
• an ignition device received in the third inner space;
• a fuel supply pipe connected to the inner casing for supplying the unreacted fuel gas discharged from the fuel cell module to the third inner space;
• and
• an air supply pipe connected to the outer casing for supplying the unreacted air discharged from the fuel cell module to the second inner space,
• wherein the water-vapor generator includes:
• a second container having a fourth inner space defined therein communicating with the first inner space through the second opening, wherein the second container is coupled to the bottom of the first container and is disposed adjacent to the outer casing;
• and
• a vaporization pipe received in the fourth inner space and having an inlet connected to an external water supply source and an outlet connected to the second module.