STEAM GENERATING DEVICE, AND FUEL CELL SYSTEM INCLUDING THE SAME

A water vapor generating apparatus includes a chamber having an inner space defined therein; a space partitioning member including a first partitioning portion, and a second partitioning portion, wherein the space partitioning member divides the inner space into a water vapor discharge space and a heating space; a first evaporation tube disposed in the heating space and in a coil shape surrounding the second partitioning portion; a second evaporation tube disposed in the heating space and in a coil shape surrounding the first evaporation tube; an inner cage disposed between the first evaporation tube and the second evaporation tube, wherein the inner cage presses against the first evaporation tube toward the second partitioning portion; and an outer cage surrounding the second evaporation tube, wherein the outer cage presses against the second evaporation tube toward the first evaporation tube.