Study On Fuel Injection Assisted Compound Regeneration Technology Of Automotive Diesel Particulate Filter

As the emission regulations are more and more rigorous throughout the world, Diesel Particulate Filter(DPF) technology has become an important way to control the Diesel Particulate emission. The study on DPF is mainly concentrated in the filter material and regeneration. The filter regeneration is the obstacles of DPF technology widely used.According to the situation of diesel and high sulfur fuel in China, fuel injection assisted compound regeneration technology of diesel vehicle particulate filter is studied in theory and experiment way.First of all, the characteristics of various fuel injection regeneration technology and typical diesel exhaust is analyzed. The composited-regeneration method which composites the fuel injection active regeneration and the fuel borne catalyst(FBC)passive regeneration is presented. The after-treatment system adopts dual filters which is regenerated one by one, the air which is needed in regeneration process is come from external air supply and exhaust according to different regeneration phase.Secondly, in accordance with requirements of the on-board regenerative burner and characteristics of different burners, the fuel-evaporation premixed vortex regenerative burner is designed. The burner uses the exhausting heat of burner to evaporate diesel fuel. The burner adopts the structure of multiple swirling air inlet to mix the diesel evaporation and air to make sure of diesel premixed combustion. In the way of 3d modeling analysis and experiment, key parameters of the structure of burner are optimized. According to the different work stage of burner, the different control map is made to reduce consume of regeneration energy and emissions and to reduce the difference of temperature in outlet field of burner.Again, the method to calculate the amount of particulate in the filter is proposed based on the pressure loss model of filter. This method considers exhaust gas flow, the exhaust gas temperature and exhaust back pressure as the main parameters to calculate the actual quantity of particulate. The accuracy of method is proved by experiment, which gets rid of the restriction of the traditional back pressure judgment method based on different types of engine and working condition. The influence of quantity of particulate to engine performance and filter regeneration performance is studied, and then the judgment method of regeneration timing is proposed on the basis of the amount of particulate.Finally, the control strategy of regeneration process is studied in theory and vehicle road experiment. The control parameter included in regeneration air flow rate, air temperature and oxygen content is optimized. On the basis of analysis of energy transformation in the process of regeneration, the strategy of exhaust assistant regeneration is studied, in order to reduce the regeneration energy and decrease the regeneration time, maintaining the high regeneration efficiency. The experiment devices have been tested on the small test vehicle team for a long time, long-term effects of regeneration temperature and FBC to accumulation of particulate rate, regeneration time,regeneration energy consume, regeneration ash accumulation and engine particulate emissions are studied, and the judgment basis of filter service life is researched.