Research on the influence of injection strategies on the in-cylinder combustion process and emissions of methanol

In the context of the global response to climate change, methanol is receiving widespread attention as a potentially clean, renewable fuel. In this paper, the effects of injection timing and split injection strategy on the combustion process and emissions were investigated in methanol engines. The effect of mixture control on the ignition delay period was studied in detail. The results showed that when the injection timing was advanced to 95 degrees CA bTDC, the ignition delay period and combustion duration period were reduced by 28.96 % and 6.14 %, respectively. When the injection timing was delayed, the NOX emissions of the methanol engine were significantly reduced by 6.13 %-20.39 %. The use of split injection strategy enables the formation of a reasonably stratified fuel-air mixture in the cylinder. Under the optimized split injection strategy, the combustion duration was shortened by 0.93 %-14.58 %. The ignition delay period of the IT105S2 was shortened by 28.62% compared with that of the original engine. In addition, the reasonable split injection strategy can effectively reduce the emission of formaldehyde and unburned methanol. This study provides an optimization direction for the application of methanol in the internal combustion engine for high efficiency and clean combustion.