Expansion of HCCI Operating Region by the Combination of Direct Fuel Injection, Negative Valve Overlap and Internal Fuel Reformation

摘要: A gasoline-fueled homogeneous charge compression ignition (HCCI) engine with both direct fuel injection and negative valve overlap for exhaust gas retention was examined. The injected directly into the residual in-cylinder during interval purpose of reforming it by using high temperature resulting from recompression. With this strategy, HCCI combustion region expanded dramatically without any increase in NOx emissions which were seen case stroke injection. Injection timing found to be an important parameter that affects width. also had most suitable value each engine'load best consumption. From result, new strategy only a portion interval, while rest intake stroke, proposed. split injection, selecting amounts fuel, further consumption improvement realized. higher load becomes, less amount required combustion. Finally, advantage utilizing combination expanding operating summarized figure as contours on speed ratio plane. effect mixture stratification reformation can utilized reduce under set conditions.