Experimental Investigation of a Self-Sustained Liquid Fuel Burner Using Inert Porous Media

A self-sustained porous burner without a sprayed atomizer was built for diesel oil. It consisted of metal fiber felt as an evaporator upstream and ceramic foam as an emitter downstream. The liquid fuel underwent film boiling in the porous evaporator and was rapidly evaporated by the heat recirculated from the porous emitter to the porous evaporator through intense irradiative heat flux. The effect of the porous structure and its installation location on the performance of the porous burner was investigated. The results indicated that the evaporation and combustion of liquid fuel could be prompted by the radiation of porous media. The position of the flame moved downstream, and the flame temperature decreased when the distance between the metal fiber felt and the ceramic foam was increased. The lowest NOx concentration was obtained when the distance between the foam and the metal fiber felt was 90 mm. When the diameter of the central hole of the ceramic foam was increased, the position of the flame moved towards the burner outlet, and the flame temperature and NOx emission declined. The flame temperature of the divergent configuration as emitter was higher than that of the convergent configuration, and the flame temperature of the C-D configuration was higher than that of the D-C configuration. Different ceramic foam structures had a significant effect on the temperature and emission in the combustion chamber, which showed that the evaporation and radiation performance of inert porous media burners with different structures is quite different.