Search Results

Ethanol direct injection plus gasoline port injection (EDI+GPI) is a new technical approach to make the use of ethanol fuel more effective and efficient in spark ignition (SI) engines. Ethanol fuel direct injection timing, as one of the primary control parameters in EDI+GPI engines, directly affects the quality of the fuel/air mixture and consequently combustion and emissions. This paper reports the experimental investigation to the effect of ethanol injection timing and pressure on engine performance, combustion, emissions of a single cylinder SI engine equipped with EDI+GPI. Firstly, the effect of EDI timing before and after the inlet valve closing, defined as early and late injection timings (EEDI and LEDI) was investigated at three injection pressure levels of 40 Bar, 60 Bar and 90 Bar and a fixed ethanol/gasoline ratio. Spark timing was fixed at original engine setting to investigate the potential engine efficiency improvement due to the EDI solely.

Ethanol has been used either as an alternative fuel or in blends with gasoline in spark ignition (SI) engines for many years. However, the existing method of using ethanol fuel by blending gasoline and ethanol fuel does not fully exploit the ethanol fuel's potential in improving engine thermal efficiency and reducing pollutant emissions. The dual-fuel injection strategy, ethanol direct injection plus gasoline port injection (EDI+GPI), offers a potentially new way to make the best use of ethanol fuel. In this paper the potential of EDI+GPI is investigated based on experiments conducted on a single cylinder SI research engine equipped with EDI+GPI. The leveraging effect of EDI+GPI on engine performance was investigated at different ethanol/gasoline energy ratios (EERs) and speeds. Then further investigation to the leveraging effect enhanced by ethanol injection timing and spark timing was performed. Experimental results showed that the IMEP increased with the increase of EER.