Improvement of the Forced Diesel Engines Cold Starting Characteristics by Oil Injection into the Cylinder

Abstract

One way to improve the cold starting characteristics is to reduce the operating loss of air mass at the compression stroke using oil injection into the combustion chamber. The article presents the results of theoretical and experimental investigation of oil injection in diesel cylinder at the cold start modes. A mathematical model of the working process in the combustion chamber is developed. The methodological basis of the synthesis engine cycle at crankshaft rotation with compressed air on the starting conditions is the system of mass and energy balances differential equations. The model takes into account the futures of engine start with compressed air and air leakage through the gap between piston and cylinder. The mathematical model allows calculating non-stationary regimes and processes. The mathematical model was implemented as a program in Matlab/Simulink environment. The experimental studies of diesel engine cold start have been conducted in the “climate” chamber. The experiment confirmed the correctness of the mathematical model. The study made recommendations to improve the starting characteristics of the forced diesel engine with oil injection into combustion chamber. The equation, based on the analysis of experimental data, allows assessing the impact of the oil mass, injected in the cylinders, and other factors on the maximum air compression pressure and temperature in the combustion chamber. Using of oil injection system can be recommended as a means to improve the forced diesel engine with cylinder diameter 150mm starting characteristics.