Partial Flow Filter Technology Research For CN4Light Duty Diesel Engine

The world market of diesel engines has developed significantly in the recent yearsbecause of their superior thermal efficiency, durability, and reliability. However, thestringent legislation limits for the amount of pollutants in exhaust gases pose somemajor challenges for the diesel engines. Therefore, mature diesel particular filtertechnology is necessary to control the PM emission of diesel engines, and it isimportant to develop the Technology of Partial Flow Filter (PFF).In this paper, based on the analysis of the PM forming mechanism and PMcomposition, applying PFF and combustion optimization to satisfy CN4emissionlegislation is put forward. This paper has researched the filter performance andregeneration performance of PFF which are the major functions of PFF. DOC isimportant as a diesel oxide catalyst for the PM filter which was tested and verified inthe experiments of this paper. In the research of regeneration performance, theregeneration chemical reactions under different temperatures were studied, and theprediction model of PM regeneration rate based on NO2and C reactions wasestablished, and then the model was calibrated with the experiment results. The lastpart of this paper has studied the failure modes of PFF and has proposed somemeasures to monitor and protect the PFF and engine. The research results of this papershow that:1) PFF technology is important for diesel engine to satisfy CN4emissionlegislation. The diesel engine could satisfy CN4emission legislation byapplying PFF technology and combustion optimization.2) The research results of PFF filter performance and regeneration performanceshows that DOC is important for the PFF, and the amount of PM could beestimated by the regeneration model. The100WHTC cycles test results alsoshow that the PFF regeneration ability was good and the filter performance hasnot declined after the test.3) The PFF regeneration might fail in the practice market applications, by PFFmonitoring and engine torque limit protection, it is able to make the risk offailure to the minimum.