Compression ignition of homogeneous charges in IC engines proposes possibilities of achieving the high thermal efficiency of DI diesel engines with low level of NOx and particulate emissions of SI engines. The objectives of this study are to further u...
Compression ignition of homogeneous charges in IC engines proposes possibilities of achieving the high thermal efficiency of DI diesel engines with low level of NOx and particulate emissions of SI engines. The objectives of this study are to further understand the characteristics of the HCCI (Homogeneous charge compression ignition) combustion, and to find practical ways of extending the rich HCCI operation limit in an engine-like environment. DME fuel is supplied either in the form of premixture with air or directly injected in the combustion chamber of a rapid compression and expansion machine under the conditions of various equivalence ratio and injection timing. The cylinder pressure is measured and the rate of he at release is computed from the measured pressure for the analysis of the combustion characteristics. Exhaust emissions are analyzed by an FT-IR (Fourier transform infrared) and a CLD(Chemiluminescent Detector). The experimental data to date show that the RCEM operates without knock on mixtures of higher equivalence ratio and exhaust emissions reduced when DME is directly injected than inducted as perfect or nearly perfect premixture.