Effects of direct-current electric fields on flame shape and combustion characteristics of ethanol in small scale

• Published in: Advances in mechanical engineering Vol. 8; no. 1; p. 1
• Main Authors: Gan, Yunhua, Wang, Mei, Luo, Yanlai, Chen, Xiaowen, Xu, Jinliang
• Format: Journal Article
• Language: English
• Published: London, England SAGE Publications 01.01.2016; Sage Publications Ltd; SAGE Publishing
• Subjects: Combustion; Electric fields; Ethanol; Ethyl alcohol; Flame temperature; Liquids; Small scale; Wind effects; direct-current electric field; combustion stability; Small-scale; micro-combustion; voltage–current characteristic
• ISSN: 1687-8132; 1687-8140
• DOI: 10.1177/1687814015624846

The aim of this work is to investigate the effects of direct-current electric fields on the behavior of the small-scale diffusion ethanol flame. The flow rate of liquid ethanol, the flame temperatures, and the flame shapes were measured. The results showed that the stable working ranges of a small-scale combustor became narrower under the direct-current electric field. The main reason was that the evaporation velocity of liquid ethanol limited by great heat loss effect cannot keep up with the increasing of combustion velocity by the ionic wind effect. The movements of those charged particles in flame enhanced the combustion process, resulting in higher flame temperatures under positive or negative direct-current electric field. The flame heights decreased with increasing applied voltages, due to the ionic wind effect increasing the flame temperature and the diffusivity. The flame voltage–current characteristic was also examined. Three regions can be divided: the subsaturation region, the saturation region, and the supersaturation region. Finally, the ratios of electric active power to actual burning thermal power of ethanol flame were calculated. It can be inferred that using the external direct-current electric field with little power consumption to control combustion and flame is a feasible method.