Numerical Simulation Of Dual-fuel Of Methanol And Diesel Combustion

The diesel engine is a highly efficient heat engine widely used in social production. That is also an important one of the energy sources. Within the cylinder, the fuel is uneven mixed with air and lacks oxygen in some place. Those cause the fuel combustion incompletely and produce a large number of emissions of soot. That is why diesel engine been constrained by the increasingly stringent emission regulations. Therefore, reducing soot emissions is an important issue to be solved in diesel engine research.In this paper, methanol and diesel dual-fuel combustion in the diesel engine to increase the oxygen content in the fuel, to change the fuel effects, and to promote full combustion of the fuel. Use n-heptane as alternative fuel of diesel, and select the appropriate detailed reaction mechanism of n-heptane and methanol. By constant volume model in Chemkin, study the dual-fuel ignition delay period from the perspective of chemical kinetics. The simulation results show that:Methanol has great influence on the ignition delay of the diesel. It inhibits the low temperature combustion reaction, promotes the high temperature combustion reaction and extends the ignition delay period of dual-fuel.The simulation study calculates the soot formation and oxidation process by the soot chemical mechanism with IC Engine model in Chemkin software. The analysis of the influence of methanol on gaseous precursors, PAH and soot formation has been done according to the combustion reaction path. The simulation results show that: methanol has few influences on C2H2and C3H3formation. But that has a significant influence on PAH formation. Methanol can reduce soot formation because it reduces the formation of PAH.Based on the calculation of the zero dimensional, coupled numerical calculation for the dual fuel is carried out using Fire software. The soot gaseous precursor and benzene which produce in the process of dual-fuel combustion have been calculated by considering the air motion in cylinder, the fuel spray, chemical kinetics and other factors. We have gotten the influence of methanol and the inlet temperature on C2H2 and benzene.