The Influence of Fuel Injection Pressure on Economic Efficiency, Technical Parameters, and Emissions of 490QZL Diesel Engine

Abstract

The operation of a diesel engine is greatly affected by the fuel injection process. This process directly impacts fuel atomization and the spray's characteristic parameters, as well as the engine's economic efficiency, technical parameters, and emissions. The present study examines how increasing the fuel injection pressure affects the operating parameters of the 490 QZL diesel engine at maximum torque using a 3D model from the AVL Fire package. The results show that increasing the fuel injection pressure from 500 bar to 3,000 bar increases the power value by 19.7% and decreases the useful fuel consumption rate by 17.6%, with a fuel injection angle of 22 degrees before the Top Dead Center (TDC) remaining constant. Soot emission decreases by 44%, with a more significant decrease observed at injection pressures ranging from 1500 bar to 3000 bar. Nitrogen Οxide (NOx) emissions slowly increase at injection pressures from 1000 bar to 1500 bar, but rapidly increase at injection pressures above 1500 bar. Hydrocarbon (HC) and Carbon Monoxide (CO) emissions decrease most markedly at injection pressures from 1000 bar to 2000 bar, at higher pressure values, the decrease is slower. Additionally, as the injection pressure increases, the length of the fuel spray increases significantly, however, the spray cone angle changes minimally due to the influence of the nozzle hole's geometrical size. Increasing the injection pressure improves the economic efficiency and technical parameters, while reducing the HC, CO, and especially soot emissions. These results form the basis for improving the diesel engine test bed at the Mechanical Laboratory of the University of Transport and Communications in Vietnam.