Simulation of CI engine powered by neat vegetable oil under variable fuel inlet temperature

Abstract Vegetable oil was being used as fuel in earlier days when the petroleum fuel supply was quite expensive and/or difficult to obtain. Later, with the ease of availability and supply of petroleum products, vegetable oil was replaced with the diesel which reduced the dependence on vegetable oil and the entire research efforts were directed towards improving the performance of CI engine using diesel fuel and the research efforts directed towards improving the performance of CI engines using vegetable oil as fuel for CI engines were reduced to very large extent. The present work describes the simulated result of the performance of a four stroke, single cylinder, air-cooled, direct-injection compression ignition engine powered by neat jatropha oil. The preheating of the neat jatropha oil is done from 30 o C to 100 o C. The performance of the engine was studied for a speed range between 1500 to 4000 rpm, with the engine set at full throttle opening and hence the engine was operated under full load conditions. The parameters considered for comparing the performance of neat jatropha oil with that of diesel fuel operation, were brake specific fuel consumption, thermal efficiency, brake power, NO X emission of the engine. The software established that i) the engine offers lower thermal efficiency when it is powered by preheated neat jatropha oil at higher speed ii) the power developed and Nox emission increase with the increase in the fuel inlet temperature iii) and the specific fuel consumption is higher than diesel fuel operation at all elevated fuel inlet temperature