Abstract: In a fuel evaporator provided with an evaporation chamber 11 that produces raw fuel gas FG by vaporizing raw fuel liquid by heat received from a plurality of heat medium tubes 12 through which a high temperature heat medium passes, a raw fuel injection portion that injects raw fuel liquid onto the heat medium tubes 12 is situated in the evaporation chamber 11. The heat medium tubes 12 are arranged sparsely near the raw fuel injection portion and densely away from it. A catalytic combustor 20 is provided adjacent to the bottom surface 11b of the evaporation chamber 11 to form the high temperature heat medium. Such a fuel evaporator efficiently vaporizes raw fuel liquid and can be suitably applied in a fuel cell system for a fuel cell-powered automobile.

Abstract: A fuel evaporator (1) includes an evaporation chamber (11) to prepare a fuel gas FG by evaporating a liquid fuel FL with heat, a fuel injector (40) to supply a liquid fuel to the evaporation chamber, a plurality of heating medium tubes (12) to lead a combustion gas HG through said evaporation chamber, a superheating part (11U) to heat a fuel gas FG evaporated in said evaporation chamber by means of the combustion gas HG, an exhaust duct (22) to exhaust the fuel gas FG, and a fuel injection tube (41). The fuel injection tube is provided with a plurality of injection holes (42), said fuel injection tube being extended into said evaporation chamber and said fuel injection tube is provided crossing at right angle with respect to a heating medium tube. Injection property of the fuel injection tube in said evaporation chamber is greatly improved. The liquid fuel is evaporated effectively and rapidly.