Investigate the Effect of Compression Ratio over the Performance and Emission Characteristics of Variable Compression Ratio Engine Fueled with Preheated Palm Oil - Diesel Blends

The performance and emission characteristics of a direct injection variable compression ratio engine when fueled with pre- heated palm oil and its 5%, 10%, 15%, 20% blends with diesel (on a volume basis) are investigated and compared with standard diesel. The suitability of raw palm oil using pre-heated in the temperature range of 90 degrees C as a fuel has been presented in this study. Experiments were conducted at constant speed of 1500 rpm, full load and at compression ratios of 16:1, 17:1, 18:1, 19:1 and 20:1. The effects of compression ratio on brake power, mechanical efficiency, indicated mean effective pressure and emission characteristics has been investigated and presented. The blend O20 is found to give maximum mechanical efficiency at higher compression ratio and it is 14.6% higher than diesel. Also the brake power of blend O20 is found to be 6% higher than standard diesel at higher compression ratio and indicated mean effective pressure of blend O20 is found to be lower than diesel at higher compression ratio. Exhaust gas temperature is low for all the blends compared to diesel. The emission of CO, HC dropped with an increase in blending ratio and compression ratio of maximum load. Also CO2 emission found to be higher than diesel. The engine performance was found to be optimum when using O20 as fuel at compression ratio 20:1 during full load condition. (C) 2015 The Authors. Published by Elsevier B.V.