Experimental Study on Submerged Combustion of n-Heptane in A Meso-scale Burner

To achieve stable and efficient combustion of liquid fuel in meso-scale burner, a porous media burner without atomizer is proposed. Porous media is used as fuel evaporator, mixer and flame holder. Flame propagation in porous media and combustion characteristics at steady state are experimentally investigated. Results shows that the axis temperature and gas temperature at outlet of submerged flame are lower than that of free flame. Besides, wall temperature of submerged flame is higher and temperature distribution is more uniform. Heat exchange between flame and wall is enhanced due to the existence of porous media. Surface flame propagates upstream into porous media when mixtures temperature is high enough, and combustion mode changes to submerged flame. Flame is stable in porous media despite large heat loss. For submerged combustion, increase of flow rate causes the axis temperature and range of luminous zone to become larger. The heat passing through the wall increases with flow rate. Since exhaust gas temperature also rises, the heat exchange efficiency of gas and wall decreases from 88.3% to 79.6%.