EXPERIMENTAL INVESTİGATIONS ON PERFORMANCE CHARACTERISTICS OF A VARIABLE COMPRESSİON RATIO ENGINE OPERATED ON DUAL FUEL MODE USING DIESEL AND BIODIESEL (OBTAINED FROM COTTON SEED OIL AND RICE BRAN OIL)

Biodiesel is recognized replacement for fossil fuel in compressed ignition engines due to its significant environmental benefits. In this study, an experimental study has been evaluated on a variable compression ratio diesel engine to investigate the optimum compression ratio, optimum blend and engine performance. Experiments were conducted on single cylinder, four stroke, variable compression ratio and compression ignition engine was operated on a dual fuel mode with diesel and biodiesel obtained from cotton seed oil and rice bran oil and its blends of B5, B10, B15 and B20 at constant speed of 1500 rpm, different compression ratios of 15, 16, 17, 18 and varying the loads. When the various proportions of biodiesel are mixed with the diesel, the equal amounts of Methyl Ester Cotton Seed Oil and Methyl Ester Rice Bran Oil are mixed together and used along with pure diesel. Engine performance test results indicated that the biodiesel blend B20 produced brake thermal efficiency decreased by 4.1% and specific fuel consumption increased by 17.1% compared to pure diesel. It is observed that in the experiments, higher compression ratio CR18 results in higher brake thermal efficiency and thus lower specific fuel consumption. From the present study, by analyzing the various performance parameters with different blends, different compression ratios and the replacement of diesel it is concluded CR18 and blend B20 is optimum compression ratio and optimum blend respectively. This study gives a direction to utilize the renewable fuel to reduce the consumption of fossil fuel