Measurement And Analysis Of The Vehicle Engine Control And Performance Parameters In The State Of Cold Start And Warmed Up

As emission regulations become more and more stringent,the operating rules of engines under steady-state operating conditions can no longer meet the requirements of traditional cars for high efficiency and energy saving.Although in the engine field,more and more researchers and engineers have noticed the importance of transient operating conditions and have carried out some research.However,there are still difficulties in the research in this direction.On the one hand,it is not suitable to obtain the operating parameters of the vehicle engine under transient conditions;on the other hand,there are few systematic studies on the operation,performance,and control parameters.In this paper,a cold and hot start-up test under NEDC operating conditions is carried out.In the experiment,the “mutual inductance principle” was used to detect the timing of engine and the phase of variable valve timing,and the “advanced sensing technology and digital-analog simulation coupling method” was used to detect the effective power and effective thermal efficiency,and the team’s "Transient Detection Principle" framework was systematically summarized.First,the study steady operation conditions,Pumping loss,RGF,the filling coefficient,the combustion efficiency,10-90% combustion duration,CA50 and combustion control parameter,summarized some influencing factors of ventilation process and combustion process.Then,the transient performance of the engine is analyzed from the aspects of the gas exchange process and the combustion process,and the intrinsic relationship between the control parameters and the performance parameters under the transient operating conditions is obtained.Finally,analyze the similarities and differences in the performance of the cold and hot starters according to the summarized operating rules.The research results show that the pumping loss under transient operating conditions is mainly affected by the throttle percentage at low load,and the phase of variable valve timing is the main influencing factor under heavy load;RGF under transient operating conditions When the load is small,because the fresh charge is less,the change in the residual exhaust gas volume dominates,so the main influencing factors are the phase of variable valve timing,at the high load,the dilution of the fresh charge dominates,so Intake pressure,parameters related to fresh charge are the main influencing factors;the charge coefficient and RGF are mainly related to the gas state in the cylinder when the intake valve is closed;the combustion efficiency is related to the coefficient of excess air changes linearly and increases with the increase of the coefficient of excess air;CA50is mainly related to the ignition advance angle and load.With the increase of the ignition advance angle,CA50 gradually decreases,that is,close to the top dead center.The increase in load also shows a decreasing trend.