Simulation Of Combustion And Emission Characteristics On A Diesel Engine With Biodiesel-diesel

Energy saving and greenhouse gas reduction have been the focus of research in the field of IC engine industries. Diesel engines are widely used in various industries for its high thermal efficiency and low exhaust gas emission. With the drying up of fossil energy resources, to seek clean and high efficient alternatives is the key to the sustainable development of diesel engine.At home in the ongoing exploration and development of alternative fuels, the goal of alternative fuels was not only in order to reduce exhaust pollution, but also in order to save and develop new energy, to relieve the internal combustion engine’s dependence on fossil fuels. At present, the main alternative fuel ware dimethyl ether, natural gas, liquefied petroleum gas (LPG) and bio-diesel, among these, bio-diesel was a kind of clean and renewable biomass energy and an excellent alternative fuel.This article used YZ4102QF diesel as research prototype, with the method of numerical simulation, has researched the influence of combustion and emission characteristics of the original engine under the condition that engines blended with different proportions of bio-diesel.Through using the CFD software AVL FIRE v2008, mesh division and establish the cylinder combustion model on YZ4102QF. Simulate, respectively, the combustion and emission characteristics of the diesel engine which was under the condition of different load rate with a fixed speed and burning the four kinds of fuel:B0, B10, B20, B50. Analyze the regulation of cylinder pressure and heat release rate, and the characteristics of fuel economy and NOX and Soot emission. The simulation results show that:blended with bio-diesel, the peak cylinder pressure decline slightly; peak heat release rate decrease, the phase advance also; the instruction slightly higher than the pure diesel fuel, and with the increase of the load, the gap of various fuel’s fuel consumption was decreasing gradually; the NOx emissions increase, and with the increase of the bio-diesel ratio, the Soot emissions decrease gradually.Bio-diesel was an oxygenated fuel, therefore, diesel engine fueled with bio-diesel will lead to an increase in NOx emissions. In order to reduce NOx emissions, this paper introduces the EGR rate, simulates and analyzes bio-diesel engine combustion and emissions.By adjusting the EGR rate, simulate and analyze the influence of engine cylinder pressure, indicating that the fuel consumption rate, and the characteristics of NOx and soot emissions, with different EGR rate.With the increase of EGR rate, the engine cylinder pressure decreases; the instructions fuel consumption rate increases while the EGR rate increase; NOx emissions greatly reduced while EGR rate increase and the smoke emission of carbon reduction is small.