Volume 4: Innovative Solutions for Energy Transitions: Part III

Combustion and Emission Characteristics of a Spark-Ignition Aviation Piston Engine Fuled With Alcohol/Kerosene Blends Guibin Liu, Zilong Li, Qiyan Zhou, Yong Qian*, Xingcai Lu

Abstract

The fuel utilized in spark-ignition aviation piston engine is undergoing a transformation from gasoline to heavy fuels (kerosene and diesel) for security reasons. To overcome the problem that kerosene is difficult to be ignited by spark but easy to cause engine knocking, in this paper, short-chain alcohols were used to blend with kerosene to improve fuel physical and chemical properties. Specifically, three kind of alcohols namely ethanol, n-propanol and n-butanol were blended with kerosene by volume fraction of 30%, 50%, 70%, respectively. Results indicated that alcohol/kerosene blends could reach higher brake thermal efficiency (BTE) (alcohol ratio ≥ 50%) compared to gasoline. The low energy density of alcohols led to the increase in brake special fuel consumption (BSFC). Excessive ratio of ethanol and n-propanol (70%) led to higher maximum pressure rising rate (MPRR). For the main gaseous emissions aspects, CO and NOx emissions of blend fuels decreased. However, the unburned hydrocarbons (UHC) and soot emissions were relatively higher. Notably, nbutanol/kerosene exhibited better emission characteristics, which have the lowest CO, UHC and soot emissions, compared with other blends. With the increase of alcohol proportion in blends, the downward trends of CO, UHC as well as soot emissions were more pronounced, while NOx emissions increased first and then decreased for ethanol/kerosene and n-propanol/ kerosene. N-butanol in 70% volume fraction led to extremely high NOx emissions.

Keywords Alcohols; Kerosene; Spark-ignition aviation piston engine; Combustion and emission; Brake thermal efficiency