Research On The Regeneration Control Strategy Of Diesel Particulate Filter

Diesel engine has a higher nitrogen oxide(NO_X)emissions and particulate matter(PM,particle mass)emissions,which restricts the development of diesel engine.Comparing to CHINA 5 emission regulations,NO_Xemission limit will cuts of about 67%to meet CHINA 6a emission regulations.On the PM emission limit,increases restrictions on PN(the amount of particulate matter).CHINA 6b emission regulations will cuts off about 33%PM emission limit.As the most effective technology to control particulate emission,diesel particulate filter will be an integral part of diesel engine after-treatment.The regeneration control of DPF is the key technology to ensure the DPF working safely and efficiently.This paper focus on the regeneration control,develops a complete regeneration control strategy,including DPF carbon loads evaluation model,regeneration process control model and regeneration degree evaluation model.Accurate carbon load assessment is the core of DPF regeneration control.This paper builds a combine model to calculation the carbon loads of the DPF,including pressure dorp model,pressure dorp simulation math model and emission and passive regeneration math model.Through the combine model,could evaluate carbon loads of DPF more accurately,to ensure the DPF system effectively capture and safety regeneration.DPF control strategy was established based on MATLAB/Simulink platform model.The modelincluding a combination DPF carbon loads evaluation model,regeneration process control model and regeneration degree evaluation model.DPF carbon loads evaluation model consists of three sub models:the back pressure model,the pressure drop mathematical simulation model emission model and passive regenerationmodel.DPF regeneration control modelincludes temperature monitoring model and uncontrolled regeneration control model.Combine model has also established a model credibility evaluation mechanism.The exhaust flow rate,excess air coefficient as boundary points,engine operation point has divided into 36 state.At each state,the credibility of the simulation results of the three models have different value,and the credibility of the model of quantitative for the final weighted average weighted average coefficient of carbon loads.DPF regeneration control model gives a scheme of regeneration process temperature control,and uncontrollably regeneration condition.Formulate a uncontrolled regeneration emergency control strategy,in order to ensure the safety of the hardware of the DPF during regeneration.DPF regeneration degree evaluation model can simulate the combustion of carbon particles base on the combustion temperature and duration of combustion.We can get the regeneration degree and Carbon residue through this model.Through diesel engine test bench,MAP and the parameters of the combine model are calibrated and identified.By simulation test,analysis shows that the regeneration control model can accurately assess the internal carbon load of DPF in different operating conditions,can ensure the DPF regeneration safely and effectively.