Study of the diesel engine working process during its operation with a fuel injection pressure of 300 MPa

The paper presents the simulation result of the influence of the ratio of the diameter of the combustion chamber Dкс to its depth hкс and boost pressure рк on the characteristics of a 1ChN 12/13 single-cylinder engine with an injection pressure of 300 MPa at a crankshaft speed of 1400 min-1. The simulation was performed with Dкс/hкс from 3,4 to 10,0, and рк from 0,15 to 0,45 MPa. The results show that the engine achieves the best performance, nitrogen oxides NOx in the exhaust gases decreases at Dкс/hкс = (7,8-10), and the pressure рк from 0,25 to 0,35 MPa. At рк = 0,35 MPa, Dкс/hкс = 10, the indicated power increases by 7,1 %. NOx reduces by 68 % but soot, CO, HC increase 4,5, 9,5, and 2,2 times, respectively. The results also show the impact of the boost pressure on spray characteristics. The boost pressure increases, the penetration, and the tip velocity decrease, but the spray angle changes a little. While the combustion chamber diameter changes, the penetration, and the spray angle change a little, and the tip velocity varies much. Changing the boost pressure is a means of redistributing the amount of fuel burned in the jet and near the wall of the combustion chamber. With an increase in the boost pressure, the proportion of fuel that burns at the beginning of the combustion process under conditions of volumetric mixing increases, while at the end of the combustion process, a large concentration of fuel is located near the combustion chamber wall.

diesel, combustion chamber, fuel injection pressure 300 MPa, boost pressure, exhaust gas