Research On The Regeneration Technology Of Post Injection Of Catalytic Diesel Particle Filter

DOC and DPF can effectively deal with particulate matter emitted by diesel engines.But how to improve efficiency and durability,and reduce the cost,have become problems to be solved urgently.In this paper,the CDPF active regeneration method of "Heat management+Post injection+Catalytic regeneration" is proposed.The control strategy of regenerative process is designed.The AVL FIRE software is used to study the pressure drop,conversion efficiency,working temperature and temperature gradient of DOC and CDPF.The engine test bench is set up to study the regeneration process of high idle.The results of the study show that:At the inlet temperature of DOC from 200? to 300?,the conversion efficiency of HC is increasing,and the conversion efficiency of HC is 95.41% at 280?.The temperature gradient of CDPF is high in the process of starting and stopping regeneration,and the temperature gradient increases with the increase of carbon load.In order to improve the fuel economy and the durability of the material,the time interval between the carbon load and the regeneration time should be controlled in a certain range.In this paper,the carbon load of CDPF is set to 3 g/L.The exhaust emission temperature can be improved to DOC working temperature by the intake throttling and other heat management methods and the PI.The steady control of the CDPF inlet temperature can be achieved by the LPI.During the progress of high idling regeneration,with the increase of regeneration time and temperature,the regeneration efficiency is increasing.Under the condition of 500? and 20 min,the regeneration efficiency reaches 98%.The internal temperature of the carrier is stable,the peak value is about 560?,and the outlet temperature is stable at about 480?,which meets the requirements of the application.The NOx concentration of the tail gas is measured in the range of 200~450? and in different system positions.DOC and CDPF can convert some NO into NO2 from 300?.The proportion of NO2 increases with the increase of temperature.