Experimental study on the application of bioethanol in dual-fuel intelligent charge compression ignition (ICCI) engine

Recently, the intelligent charge compression ignition (ICCI) combustion mode was proved to be very efficient for the internal combustion engine. Bioethanol is one of the most available renewable fuels at present. In order to improve the utilization efficiency of ethanol in internal combustion engine, this study tested the combustion and emission characteristics of bioethanol-diesel in ICCI mode at various bioethanol substitute ratios and injection strategies. The results demonstrated that with bioethanol substitute ratio of 64% similar to 68%, the indicated thermal efficiency of the engine reached high level (50.1%), and the engine emissions decreased to a low level with ultralow NOX (below 1 g/kwh) and particulate matter (particle number close to 1 x 10(6)/cm(3)). The bioethanol double-injection strategy at 3:1 split ratio intensified the stability of the local heat release process, increasing thermal efficiency by 1.4%. Increasing bioethanol injection pressure diminished the possibility of local misfire increasing combustion efficiency. The dilemma of nucleation particle, HC, and CO emissions due to the low average temperature at the end of combustion could be solved by increasing bioethanol injection pressure.

Automated summary

The study demonstrated that the ICCI combustion mode with bioethanol-diesel blend can significantly improve the thermal efficiency of internal combustion engines and reduce emissions levels. The stable combustion process and reduced emissions were achieved with a 64% bioethanol substitute ratio.