Research On The Fibre Filtrating Material Diesel Particulate Filter Character And Regeneration Control System

In the background of the global oil crisis and environmental pollution, diesel engine get more people's attention with it's better fuel consumption and emission performance. But diesel engine exhaust more particulate matter than the gasoline engine, and these particles will caused serious influence to human health. Thus reducing emissions of exhaust particulates of diesel becomes one of the important conditions of further widely used of diesel vehicles. In the present researches and applications, exhausts post-processing technology becomes one of the most successful methods to solve this problem. As a typical representative, in practical application diesel particulate filter gain greater success, but also exist some problems,such as high back pressure and inconvenient regeneration which are closely ralated with the performance of the filter materials. Fibre filtrating material is an important diesel particulate filter materials, but currently lack of the theory research about fiber materials as exhaust particles filtration material. Thereby establishing the pressure drop and filtration efficiency model for fiber materials and on this basis establish computer simulation method for designing diesel particulate filter have great significance. On the other hand, it will realize the automatic regeneration of diesel particulate filter and dvelop new diesel particulate filter regeneration methods by reducing the adhesive force between filter material and exhaust particles.Studying surface adhesion properties of fiber filter materials by experimental method and exploring the method of lowing the adhesive force between filter materials and exhaust particles are the important basis of studying self cleaning diesel particulate filter.Basis of previous work,the research established the pressure drop and filtration efficiency model for fiber materials when used in particle trap and the mathematical model of diesel exhaust particulate drag force.Based on these works, the research applyed fluid dynamics simulation software--FLUENT established computer simulation method of fiber materials pressure drop,filtration efficiency and filter cake distribution.At the same time,the research changed wire mesh's surface shape and researched it's surface wetting characteristics through the experiment method. Establishing the parallel particle trap's control strategy and designing the valve actuator.We got some useful conclusions by analyzing experiment and mathematics model.The adoption of two parameters of permeability and inertial coefficient can well describ the characteristics of wire mesh pressure drop.For exhaust particles, fiber filter materials in diameter of 200-400nm have lowest capture efficiency, inertial mechanism is the main filteration mechanism to influence these particles. To reduce the diameter of filter material fiber and filtration velocity is the most effective method to improve the filtering efficiency.After surface chemical plating Ni-P coating,wire mesh surface wetting characteristics have been improved obviously.Deposition coefficient can be used as a standard to judge the regeneration time,adopting stepping motor as a parallel trap valve driver can satisfy the valve movement and positioning requirement.