Combustion Numerical Simulation Of Biodiesel And Its Application Research On JX493Diesel Engine

Biodiesel is the clean and renewable energy. Its application can not only alleviate the serious increasingly energy crisis, but its products of combustion lower the pollution of environment. Biodiesel is very similar with diesel, which can be directly used in diesel engines. Biodiesel has a large molecular weight and high viscosity, which resulting in the fuel atomization even worse and penetration distance increases. This has an important influence on the combustion. Meanwhile, biodiesel is an oxygenated fuel, and the oxygen can improve combustion and reduce soot emissions. But. many studies have also found that the addition of biodiesel make the emissions of NO increase.In this paper. JX493diesel engine fueled with mixture fuel of biodiesel and diesel has been studied through the simulation and experimental method. The experimental part selects the mixture fuel B20, in which the volume fraction of biodiesel is20%, and diesel as compared. The experimental results shows that the mixture fuel added with biodiesel makes the peak of combustion pressure increase and the corresponding crank angle somewhat in advance. This is mainly due to the oxygen contained in the biodiesel making combustion more fully, while the biodiesel’s shorter ignition delay period and injection advance make burning forward. which is because of biodiesel’s compressibility.Through the zero-dimensional simulation software of CHEMKIN. different mechanisms of methyl butanoate and methyl decanoate were used to analysis the ignition delay and the oxidation path in biodiesel combustion. Then, the multidimensional simulation software of FIRE is used to contrast the spray and emissions when JX493diesel engine fueled with different fules of diesel and B20. After that injection angle is adjusted to analysis its impact on emissions. At last, coupling model is established with mechanism of ERC-mb. and the effect of chemical reaction rate and turbulent mixing in the numerical simulation of biodiesel combustion is dicussed. After the simulation, conclusions were got. Biodiesel makes the penetration distance of B20longer and droplets diameter larger than diesel in the initial spray. The NO emission of B20increased significantly, and by putting off the injection timing1deg. NO and soot emissions both reduced. Using the simplified mechanism of ERC-mb, coupling calculation of biodiesel becomes simple, with the accuracy of results. Coupling model can make a clearer understanding of biodiesel’s combustion process in the cylinder and intermediate combustion products, considering detail combustion mechanisms and spray characteristics of different fuel.