압축착화엔진에서 바이오디젤의 연소 및 배출물 특성에 관한 연구

Abstract

Abstract

A Study on Combustion and Exhaust Emissions Characteristics in a Compression Ignition Engine fueled with Biodiesel Blended Diesel Fuel

Jho, Yongwoo Directed by Professor Lee, Chang Sik, Ph.D. Department of Mechanical Engineering Hanyang University The aim of this study was to confirm the effect of soybe an biodiesel, and canola biodiesel with blended diesel fu el on the combustion and emission characteristics of four -cylinder direct injection passenger vehicle diesel engi ne. In order to analyze the combustion and NOx, soot emis sion reduction characteristics, the experimental conditio ns applied by various parameters, such as an engine speed, engine load, injection pre ssure and fuel blending ratio. Also, the experimental results of biodies el blended dies el fuel are compared to the results of pure diesel combus bution and emission characteristics. In this study, the test engine has a compression ratio of 17.3, a displacement volume of 1.582L and maximum fuel injection pressure up to 160 MPa. Test fuel were used for six kinds of fuels such as BD10 (ULSD 90%, soybean biodie sel or canola biodiesel 10%), BD20 and BD40. Also, the ex perimental results of biodiesel blends were compared to those of ULSD. In order to control engine load, the dynamometer system used to an EC dynamometer and a control program. In this investigation of experiment results, engine measuring data values were obtained by using data aequsition board and its acquisition program to analyze combustion charac teristics. The exhaust gases from the test engine were me asured with a NOx, HC, CO emission and a smoke analyzer. The experimental results showed that the ignition delay of BD40 was adv anced compared to ULSD because biodiesel has oxygen content about 11%,so it brought about early ignition than ULSD. In the results of engine combustion characteristics, combustion pressures and heat release rates of b iodiesel and blends showed the similar charact eristics at 1000rpm and 20 00rpm. But the combustion char acteristics due to engine load condition shows different result because increasing engine load,injection quantity. The experimental results showed that IS-NOx and IS-Soot emissions indic ated the trade-off relations. When injection pressure and blending ratio are increased, IS-NOx emission is increased but IS-Soot emission level decreased. In theoretical view point,IS-Soot emission decreases with the increase of fuel injection pressure due to the better mixing effect between fuel and air.