Combustion and performance analysis of direct injection, compression ignition engine fuel with preheated neat cotton seed methyl ester

Abstract

In many countries, methyl esters of vegetable oils are blended with petroleum diesel and used as a partial substituent to petroleum diesel. In our experimentation, neat cotton seed methyl ester (without blending) was implemented as fuel for a direct injection compression ignition engine. Cotton seed methyl ester cetane number and calorific value are close to petroleum diesel. But the flash point, auto-ignition temperature and viscosity are higher than petroleum diesel. If it is preheated, the viscosity will decrease and flow ability in the fuel lines will increase. While injecting, the atomization level of the fuel was also improved by the preheating. But too much heating is not preferable, because it causes formation of vapors in the fuel lines. Preheating of methyl ester to the correct temperature gives better thermal efficiency and lower environmental pollution. Hence in our investigations, cotton seed methyl ester is preheated to different temperatures (27°C, 35°C, 40°C, 45°C, 52°C and 55°C) and implemented as fuel for a direct injection compression ignition engine. At these temperatures, engine performance, fuel combustion and pollutants in the exhaust gas are analyzed. It was found, preheating of cotton seed methyl ester to a temperature between 45°C and 52°C gives lower pollutants and better thermal efficiency.