Influence of Combustion Duration on the Performance and Emission Characteristics of a Spark-Ignition Engine Fueled with Pure Methanol and Ethanol

In this research, we estimated and summarized the effects of combustion duration on the performance and emission characteristics of a spark-ignition engine using pure methanol and ethanol as fuels, which have not been previously presented. From the results, we demonstrated that an increase in combustion duration causes a decrease in peak firing temperature and peak firing pressure and an increase in trapped residual gas. The level of trapped residual gas when using ethanol as fuel is higher than that of methanol fuel. The indicated mean effective pressure (IMEP) and brake mean effective pressure (BMEP) increase to maximum values and then decrease with increasing combustion duration, while the brake specific fuel consumption (BSFC) reaches a minimum value and then increases. The optimal BSFC improved to 33.31% when the engine used ethanol fuel instead of methanol. The increase in combustion duration helps to reduce NOx and HC emissions, but an increase in CO emissions is observed.

Automated summary

In this research, the effects of combustion duration on the performance and emissions of a spark-ignition engine using methanol and ethanol fuels were estimated and summarized. The results showed that increasing combustion duration leads to a decrease in peak firing temperature and pressure, and an increase in trapped residual gas. The level of trapped residual gas is higher with ethanol fuel compared to methanol fuel. The indicated mean effective pressure and brake mean effective pressure initially increase and then decrease with increasing combustion duration, while the brake specific fuel consumption reaches a minimum and then increases. The optimal brake specific fuel consumption improved by 33.31% when ethanol fuel was used instead of methanol. Increasing combustion duration helps reduce NOx and HC emissions, but leads to an increase in CO emissions.