Experimental investigation on the electrospray counterflow flame in a small combustor with a porous media as the grounding electrode

Abstract

An experimental study on electrospray counterflow combustion of ethanol in a new type combustor with a porous media as the grounding electrode is carried out. The electrospray process of ethanol is separated from the combustion system for visualization and four typical spraying modes are identified. The characteristics of electrospray counterflow combustion are discussed. Four flame shapes are classified and the distribution region is determined. The results demonstrate that the double-layer flame and dromedary flame are easier to be observed. The change of fuel mass fraction can significantly affect the flame diameter and temperature. When the fuel mass fraction YF > 0.075, the increase of carrier gas flow rate promotes the fuel evaporation. Ethanol vapor is carried into the porous media, and the flame diameter and temperature are incrensed. When YF < 0.075, the dilution of ethanol vapor by carrier gas is dominant, resulting in the decrease of fuel concentration. The combustion efficiency and ratio of CO2/CO is highest at the dromedary flame, and the maximum combustion efficiency and ratio of CO2/CO are 95.25% and 7.78 for Φ = 0.76 respectively, which means a very efficient conversation of fuel. The results gained insights for the design and operation of electrospray counterflow combustors.