Abstract: Experimental system of porous medium burner with electric preheating was developed to realize a self-sustaining combustion of liquid fuel without second ignition. Based on the stability of the electric preheating temperature field, the flame characteristics and the temperature variation of the diesel oil pre-evaporation combustion within porous media were analyzed, and the influences of the equivalence ratio and the air mass flow on the combustion characters were discussed. The results indicate that the electric preheating system shows a strong stability, and the minimum preheating temperature for a stable combustion is about 750℃. Two types of flame forms, the stable flame and the filtration combustion flame, are found during the process of the liquid fuel pre-evaporation combustion. The highest temperature of the stable flame which is similar to the premixed combustion is 1140.2℃, and the propagation velocity of the filtration combustion flame is near 1m/s. As the gas mass flow increases, the stable flame moves to downstream and the burning becomes more completely. Equivalence ratio has more significant effect on the temperature distribution than that on flame propagation.

Key words: electric preheating; porous medium burner; self-sustaining combustion; filtration combustion flame