Research On Internal Friction Power And Instantaneous Driving Torque Of Internal Combustion Engine

The energy conservation and emissions reduction of engine is one of the most effective measures to reduce the fuel consumption and emissions. In general, about 30% of engine energy is outputted by the crankshaft. Friction heat production of engine account for about 10% of the total energy, in some states, it is highly about 25%. Own to the cylinder maximum explosion pressure of diesel engine is higher and the friction power consumption proportion is much bigger, so that the energy conservation and emissions reduction of engine can be improved by reducing engine friction power consumption. Frictional system of engine is consisted by multiple friction pairs, establishing accurate mathematical model of the friction components and researching characteristics of friction power consumption is considered. Besides, the method of reducing friction power consumption of the whole system is researched. In this way, it is a great significance to improve the fuel economy and reduce the HC in the exhaust gas, CO and NOx emission.In the study of friction power consumption and simulation of engine, the main research of the friction components include piston, bearings,valve-train and accessories. Based on the characteristics of hydrodynamic lubrication, mixed lubrication and the boundary lubrication, according to the actual situation of engine components, model of different friction coefficient is established. Considering the deformation of bearing and cylinder, the influence of temperature on the oil viscosity factors, the whole friction system was established.Application of the labVIEW software program, the main friction pairs are simulated in transient conditions and steady conditions respectively. Designing drag experiment bench experiment scheme of engine, friction power consumption is simulated at different rotational speed.The whole internal friction power consumption, instantaneous drive torque and the transient friction power consumption can be quickly simulated at different rotation speed and the crankshaft angle. By comparing the simulation and experimental results, they can match each other very well. In this way, mathematical model of internal friction power consumption is tested very accurate, and the results can provide theoretical basis for the optimization and calibration of friction MAP of engine system.