Research Of In-Cylinder Combustion Of Methanol Engine For Non-Road Application By Numerical Simulation

As air pollution and energy crisis become more serious,the search for diversified and efficient clean engine fuels is highly valued.Methanol is one of the most promising alternatives to decarbonizing the non-road energy use industry.When methanol fuel is applied to road(ie,vehicle)engines,the operating conditions of the vehicle engine are often at medium and low loads,and the working conditions are more complicated.The low calorific value of methanol has a significant impact on the performance of the vehicle engine.At the same time,the transient load of the vehicle engine changes rapidly,while the transient response speed of the methanol engine is low.However,non-road engines(such as generators)are stable at medium and high load for a long time,which weakens the influence of low calorific value of methanol fuel on engine performance,and effectively avoids the weakness of low fuel value of methanol fuel.This paper presents a numerical simulation of the performance and emission characteristics of neat methanol and diesel/methanol dual fuel combustion processes based on Yuchai YC6 M series Heavy-Duty engine bench tests.An effective reduction of soot emission was observed with increased methanol content in the blends.Nitrogen oxide(NOx)and soot emission control strategies were also investigated at length.At high loads,if the mass fraction of methanol in the blend is controlled less than 40%,the NOx emissions of the engine would be decreased by 12%.In addition,ambient atmospheric pressure and temperature are important factors affecting the comprehensive performance index of diesel engines.As altitude increases,atmospheric pressure and temperature decrease while the air volume and air temperature entering the cylinder per cycle decrease,which directly affects the non-road engine.Performance in the plateau environment degrades while the power,economy,and emission performance of the engine significantly deteriorate.In this paper,numerical simulation is used to clarify the effect of oxygenated methanol as fuel on the performance of the engine at high altitudes.The results show that when the methanol mass fraction is about 40%,the engine power reduction rate in the high altitude region is slower than that of the diesel engine due to the oxygen introduced by the methanol.Moreover,when the mass fraction of methanol is lower than 40%,the NOx emission of methanol engine decreases with the increase of altitude,and the NOx emission of methanol engine at altitude of 4000 m is lower than that of sea level.