Development and testing of a mathematical model of the engine pre-start operation at low ambient temperatures

Starting a cold diesel engine, in the Arctic, with minimum temperatures below -60 ° C, presents significant difficulties due to: low temperature of the air charge; increased resistance to cranking the crankshaft and moving other kinematically related parts (pistons, parts of the gas distribution mechanism; etc.) due to the increased viscosity of the oil, deterioration of fuel atomization conditions, enhanced heat transfer to the cylinder wall, loss of part of the air charge. This article is devoted to solving the urgent problem associated with the development of a theoretical framework that provides comprehensive simulation of the starting mode of a diesel engine at low ambient temperatures when using start-up facilitators. The article proposes a mathematical model of a diesel engine, based on thermal mechanics (thermodynamics of open systems), which reflects the main features of an internal combustion engine (ICE) as a system that converts energy over time. The system of equations of the mathematical model is based on the laws of conservation of energy, mass, equations of motion of solid links and includes differential equations of the rate of change of temperature and density of the working fluid in the cylinder and in the engine crankcase, ideal gas equation of state, as well as differential equations of change of angular velocity and angle of rotation of engine shaft. The mathematical model is tested on the example of a 1CH9.5 / 8.0 diesel engine. The article presents graphs of changes in the angular velocity, pressure and temperature in the cylinder, as well as the results of calculating the engine pre-start operation at various low ambient temperatures in comparison with the results of full-scale experiments conducted in the refrigerating chamber.

diesel, low temperatures, prestart mode, mathematical modeling