Abstract
Effect of impurities of fuel, which are worried to mix during producing and delivering when DME fuel for vehicles is put on a market, on DME powered diesel engine performances were investigated with negligible emission DME engine installed a common-rail fuel injectin system by partial load stable mode and Japanese transient mode(JE05 mode) test. Water has a most harmful influence on increasing unburned emissions and formaldehyde. Blending FAME increase CO emission in low excess-air ratio conditions, and HCs emission is increased compared to other impurities. Propane mixing increase THC slightly in medium load conditions. Methanol mixing increase THC and CO emissions slightly in low excess-air ratio conditions. Oxidation catalyst cannot decease CO, THC and formaldehyde emissions when the catalyst temperature isn't enough high. However, any tendencies of impurity's effects on emissions cannot catch by JE05 mode test.
