Name : The 10th International Conference on Modeling and Diagnostics for Advanced Engine Systems (COMODIA 2022)
Date : July 05, 2022 - July 08, 2022
Polyoxymethylene dimethyl ethers (PODEn) has the characteristics of high cetane number and high oxygen content. It is a promising alternative fuel for diesel engine. In order to explore the effect of natural gas substitution rate on the combustion and emission of PODEn pilot natural gas engine under low load, the combustion and emission parameters in the cylinder when the natural gas substitution rate is 40 ~ 90% are compared and studied by using the CONVERSE 3D simulation model. The results show that with the increased of natural gas substitution rate, the peak cylinder pressure decreased, the combustion phase advanced, the ignition delay period prolonged and the combustion duration increased. When the natural gas substitution rate is 40 ~ 60%, the heat release rate curve shows double peaks and the emissions of HC and SOOT are lower; When the natural gas substitution rate is more than 70%, with the increased of natural gas substitution rate, the incomplete combustion of natural gas in the cylinder increased, and CO and NOx emissions reduced. When the natural gas substitution rate is 90%, a low proportion of PODEn causes misfire. When the natural gas substitution rate is 80%, as the pilot fuel with SOI sweeping from 0 ° to - 25 ° ATDC, the peak in-cylinder pressure and heat release rate first increased and then decreased. When the injection timing is - 10 ° ATDC, the peak in-cylinder pressure and heat release rate are the highest. CO, NOx and SOOT emissions first increased and then decreased with the advanced of injection timing, while HC emissions first decreased and then increased with the advanced of injection timing. Early and late injection timing are not conducive to the combustion of natural gas.
