| Popis: |
Cold diesel start-up, in Arctic conditions with minimum temperatures below −60 °C, presents significant difficulties due to: low air charge temperature; increased resistance to cranking the crankshaft and moving other kinematically related parts due to increased oil viscosity; deterioration of fuel atomization conditions; increased heat transfer to the cylinder walls; loss of part of the air charge. This article is devoted to solving an urgent problem related to the development of a theoretical model that provides a comprehensive simulation of the pre-start mode of the diesel engine in low ambient temperatures when using means to facilitate start-up. 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 speeds of temperature and density of the working fluid in the cylinder and in the crankcase of the internal combustion engine, the ideal gas equation of state, as well as differential equations of change in the angular velocity and angle of rotation of the engine shaft. The mathematical model was tested on the example of a diesel engine 1H9,5/8,0. The article presents the results of calculations of the pre-start mode of the engine operation at various low ambient temperatures in comparison with the results of full-scale experiments conducted in the cooling chamber or the complete chapter. |
