Effect of Fuel Injection Pressure and Preheating on the Performance and Emissions of a Vegetable Oil Fuelled Diesel Engine

In the present investigation, waste frying oil, a non-edible vegetable oil is used as a diesel fuel substitute. Performance and emission tests were carried out in a naturally aspirated, single cylinder, direct injection diesel engine with and without preheating the waste frying oil and with fuel injection pressures of 190 bar, 210 bar, 230 bar and 250 bar. Performance parameters such as brake specific energy consumption and brake thermal efficiency and emission parameters such as NO_x and smoke density were evaluated at various operating conditions. Increasing the injection pressure with and without preheating the fuel is found to improve the performance and reduce smoke emissions. At these conditions, the NOx concentration is seen to increase, however it is lower than pure diesel operation.