Effect of Injection Pressure on Performance, Emission and Combustion Characteristics of D I Diesel Engine Running on Blends of Jatropha Methyl Esters and Diesel Fuel

Due to the increasing demand for fossil fuels and environmental threat, a number of renewable sources of energy have been studied worldwide. An attempt is made to assess the suitability of vegetable oil for diesel engine operation, without any modifications in its existing construction. One of the important factors which influence the performance and emission of diesel engine is fuel injection pressure. A single cylinder constant speed air-cooled four-stroke direct injection diesel engine of 4.4 kW is selected for the experimental investigations to evaluate the performance, combustion and emission characteristics fuelled with methyl esters of Jatropha oil (JTME). The performance parameters are analyzed include Brake thermal efficiency, specific fuel consumption, and exhaust gas temperature whereas exhaust emissions include oxides of nitrogen, HC, Smoke and CO. The results of the experiment in each case were compared with baseline data of diesel fuel. It concluded that lower blends of biodiesel 20%JTME act as best alternative fuel among all tested fuel at full load condition.

Tests are conducted on CI engine fuelled with diesel at Injection pressure of 200 bar to get base line data for comparing engine performance and emissions with 20% JTME as fuel at different injection pressures (200, 210, 220, and 230 bar). The results indicate that the performance of engine is improved with 20% JTME at injection pressure of 220 bar compared at different injection pressures. The results indicated that the brake thermal efficiency is increased about 1.26% for 20% JTME at 220 bar compared to 200 bar injection pressure. It is also observed that CO, HC and Smoke are lesser for 20% JTME at 220 bar compared at different injection pressures. The nitrogen oxide emission (NO) was increased for 20% JTME with 220 bar injection pressure. However 20% JTME can be used at higher injection pressure safely in a conventional CI engine without any engine modification that could help in controlling air pollution.