Partial model of filling the engine cylinder with residual gas recirculation

Abstract

The determination of the cylinder filling value with the help of the engine's electronic control system is very important, since an error in its calculations directly affects the toxicity of exhaust emissions and fuel efficiency, as well as the energy performance of an internal combustion engine (ICE). The value of the cylinder air flow is involved in the calculation of both fuel injection and determination of the effective torque, and is the main argument in choosing an angle function preceding ignition (API). Also, its values are necessary to control the throttle position and the angular positions of the camshafts, as well as to control the boost pressure. Mathematical models for calculating cylinder filling, which are based on the model of the partial pressure of exhaust gases used in the ICE control systems algorithms are considered. The article analyzes several algorithms of different control systems in order to identify the causes of a systematic error in the calculation of cylinder filling. This analysis has shown the following results: in all the models of cylinder charge based on exhaust gas partial pressure and considered in the article, the influence of the partial pressure of recirculating residual gases in the valve overlap phase on the amount of air filling the cylinder had not been taken into account. A cylinder filling model has been proposed, which was also based on the principle of partial pressure of gases, but considering the recirculation of residual gases. The calculation results of cycle filling based on the proposed method were given as well as the results of its verification.