A Study of Low Compression Ratio Diesel Engines Operated with Neat Dimethyl Ether (DME)

A new concept of using DME as an alternative fuel in direct injection compression ignition engines with low compression ratios was presented to seek a combustion regime with the highest thermal efficiency. The concept was experimentally evaluated by a comparison of performance and emissions between a DME fueled engine and the corresponding conventional diesel engine. The result demonstrated that the DME fueled engine is superior to the conventional diesel engine in terms of thermal efficiency, emissions and engine noise particularly at low compression ratios. However NOx emission is unacceptably high and needs to be reduced by EGR or after treatment systems.