Dependence of HCCI Combustion on Compression Ratio and Fuel Property in a Gasoline Direct Injection Engine

In this paper,multiple injection strategy and variable valve technology were utilized to achieve SI/HCCI hybrid combustion in a gasoline direct injection engine.The effect of HCCI combustion and emission on different compression ratios and fuel properties were investigated.The results show that gasoline HCCI combustion demonstrates single-stage heat release process.Ignition near TDC leads to lower fuel consumption.Lower compression ratio leads to richer HCCI combustion with higher NOx emission.Higher octane gasoline leads to narrower HCCI load operation range.Gasoline HCCI engine fueled lower octane fuel with lower compression ratio can achieve better performance on economy and emission.