Studies on performance and emission characteristics of a variable compression ratio engine using ether gasoline blends

Abstract

Additives are the new and alternate renewable fuel that can be directly used as fuels in petrol or gasoline engines. However, their high volatility and little lower caloric value lead to reduce the thermal efficiency and increase in specific fuel consumption to some extent. But there is significant change in emissions such as carbon monoxide, carbon-dioxide, hydrocarbon, smoke density and oxides of nitrogen. In the present work, an experimental study has been carried out to estimate the engine performance, and emission characteristics of petrol engine fueled with ether oxygenates as blends in different volumetric proportion with petrol. The objective of this study was to determine the properties of blends, to investigate the effect of compression ratio on combustion and to check the performance and emission characteristics of gasoline engine for the blended fuels namely M10,M20,M30,M40 of methyl tertiary butyl ether (MTBE) ,D10, D20, D30, D40 of Di-iso-propyl ether (DIPE), DE10, DE20, DE30, DE40 of Di-ethyl-ether (DEE). In line with the framed objective, a single cylinder four stroke multi-fuel, Variable Compression Ratio (VCR) petrol engine developing a different load of 2, 4, 6 and 8 (kgs) at 1500 rpm was used for experiments. The engine performance was investigated with compression ratio of 8:1, 9:1 and 10:1 at full load condition. From the test results, the compression ratio of 10:1 was identified as optimized value for the better performance and lower emissions. Base data was generated by using pure gasoline as fuel. The engine was operated with constant spark timing and speed of 1500 rpm at optimized compression ratio 10:1 for all loads under steady state conditions using all the blends, as fuel. The blend which delivered the best performance when used in engine has been identified for optimized compression ratio The result indicates that optimum blend M 40 (40% of MTBE+ 60% of petrol) at compression ratio of 10:1 and full load are found to be suitable to have better results in terms of performance such as specific fuel consumption and brake thermal efficiency and emissions such as hydrocarbon, carbon monoxide, smoke density and oxides of nitrogen and carbon-di-oxide, and combustion characteristics such as heat release rate. The results are compared with neat petrol operations at full load condition. The blend M40(40% of MTBE+60% of petrol) shows reasonable reduction in emission namely HC decreased by 20.77%,CO decreased by 46.03%,CO2 increased by 2.70%,smoke density reduced by 3.44 % ,NOX increased by 7.97 % and with little lower performance of SFC increased by 3.03%,BTE decreased by7.6% and combustion of heat release rate decreased by 3.46% when compared with that of neat petrol. newline