| With the deepening of environment protection and atmosphere management and the severe requirements of pollution regulations, particulate emission control has become a grave topic of atmosphere pollution management and diesel engine production. For its high filtration efficiency and good reliability, et al, diesel particulate filter (DPF) has been the research focus of the current vehicle particulate emission control technology. It has been recognized as one of the most effective means to solve the problem of particulate emission for diesel engine. From the view of research process, regeneration technology has been the key of particulate filter technology, which restricts the development of particulate filter technology.Currently, many DPF regeneration ways have been proposed and been given a lot of research respectively. The research of catalytic regeneration, infrared and microwave regeneration, etc abroad is much more than in domestic because of being restricted by domestic oil due to high component of sulfur, arsenic and plumbum, etc. In domestic, the periodic or continuous pyrogenation method is usually used to clean the captured particulate in filter in order to ensure the well continuous working performance of DPF. In many pyrogenation regeneration methods, the burner-type system technology isn’t restricted by fuel quality of the high content of sulfur and so on in our country. It is adopted the same fuel in core device-burner as diesel engine, and not made great changes for the original engine structure with the DPF in vehicle. In addition, it is not restricted by the exhaust temperature and can be carried out the regeneration under all working conditions with wide regeneration window, etc., it provides a new way to reduce the diesel particulate emission. The contents for thermal parameters models and control process have been studied based on a full flow burner-type DPF.At present, the research on burner-type DPF is very popular whether in abroad or at home, it mainly focuses on design and optimization of the burner, and its combustion performance and experiment research, etc., but there are little systematic researches on the control model of thermal parameters in the regeneration process. Therefore, based on the projects, such as the National Natural Science Foundation of China-Compound regeneration mechanism research of microwave and cerium-manganese additive on porous medium of diesel particulate filter (ID:50876027), the sub-item of National863project-R&D of a new generation environment-pretection and efficient engine"(ID:2008AA11A116) and Hunan Provincial Natural Science Foundation of "gas-particle two phase flow and combustion numerical simulation of vehicle diesel particulate filter in the compound regeneration process"(ID:06JJ20018), etc. The burner-type regeneration technology has been studied as follows:(1) Taken the wall-flow honeycomb ceramic filter as the research object, the numerical regeneration model of the burner-type DPF is built. Through the numerical coupling solution, the DPF regeneration process, influenced by the main thermal parameters of burner-type regeneration such as ratio of fuel to gas, injection pressure, injection rate, air-supplied quantity and other parameters like initial particle deposition quantity, exhaust mass flow and so on, have been calculated and analyzed. The influence laws provide a theoretical guidance to modeling, optimal control and control system study in DPF regeneration.(2) Based on above model, the regeneration numerical model of the inlet channel has been simplified. Combined with the steady-state Semenov theory and Adler/Enig’s batch reactor theory, the inlet exhaust critical temperature model for filter regeneration has been built on the base of consumption reaction, and its influence factors have been analyzed. It is greatly significant to design and adjust the burner power.(3) Considered the nonlinear changes of DPF back pressure under engine’s non-steady state working conditions, the influenced factors of dynamic response of the DPF backpressure signal acquisition system have analyzed and discussed. Based on the numerical model of the exhaust back pressure of the wall-flow honeycomb ceramic filter, the theoretic dynamic response numerical model of DPF pressure measurement system has been built, it provides theoretical basis for improving the measurement accuracy and response performance for the backpressure.(4) The exhaust backpressure threshold MAP of DPF has been built based on the total fuel consumption and the regeneration time has been determined by the exhaust back pressure method. To obtain the regeneration backpressure threshold MAP, the engine simulation model equipped with the DPF of the burner-type system has been built in AVL BOOST software. After the experimental validation, the model can be used to simulate the exhaust backpressure, fuel consumption and other results. The results have been put into MATLAB, with its powerful function of mathematic calculation and capabilities of graph disposal, and then the regeneration exhaust backpressure MAP of DPF under all engine’s working conditions has been built with the least square method and linear interpolation technology based on the theory of multiple linear regression.(5) The burner injection optimal control model has been improved. Combined with the inlet channel regeneration critical temperature, the terminate temperature in the boundary condition has been strengthened reasonably. The corresponding optimal control model of air-supplied quantity has been added. With the inner point penalty function method and logistic chaos optimization algorithm, the corresponding optimal control values of the improved model have been compared with the original model. It makes the foundation for the intelligent optimal control process for burner-type DPF.(6) A more systematic control strategy for a burner-type DPF has been proposed and analyzed its characteristics. And the hardware design and program debugging for the control system has been made. From the randomly selected DPF regeneration experiments, it shows that DPF can be regenerated timely, accurately, securely, efficiently and reliably.The research provides the theoretical basis and technical reference for burner-type DPF in structural design, performance analysis and regeneration control etc. and lays the foundation for its practical. Some methods of the research and results have important reference value to other type DPF too. |
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