Effect of Injection Pressure and Preheating on the Performance and Emissions of a Waste Frying Oil Fuelled Diesel Engine

In the present investigation, waste frying oil was used as a diesel fuel substitute. Performance and emission tests were carried out in a naturally aspirated, single cylinder, direct injection die sel engine with and without preheating waste frying oil and with fuel injection pressure of 190 bar, 210 bar, 230 bar and 250 bar. Combustion parameters such as peak cylinder pressure and net heat release rates, performance parameters such as brake specific energy consumption and brake thermal efficiency and emission parameters such as NO_X and smoke density were evaluated. The maximum heat release rate was found to increase with increase in injection pressure with and without preheating the fuel. Engine performance was improved and there was reduction in smoke density. The NO_X concentration increased with increase in the injection pressure and preheating the fuel.