Effects of Diesel Particulate Filter Structural Parameters on
Filtration Performance of Different Size Particles

TAN Piqiang¹  HU Zhiyuan¹  LOU Diming¹  WAN Gang¹  LI Zhijun²

(1. School of Automobile, Tongji University, Shanghai 201804;
2. State Key laboratory of Engines, Tianjin Unversity, Tianjin 300072)

Abstract: In this study, microcosmic capturing mechanism of single unit on diesel engine particles is firstly studied, then, macroscopical filtration model of single porous medium bed and trap model of monolithic wall-flow diesel particulate filter (DPF) on particulate matter (PM) are developed and formulated. Effects of main DPF structural parameters on filtration performance of different size particles from diesel engines are studied. The results show that the trap efficiency of 10 nm diameter particles is highest, and the efficiency descends while the particle diameter increases. The trap efficiency will be lowest near 500 nm diameter particles, and the trap efficiency ascends with particles diameter increasing to 1μm continuously. This indicates the complex effects of diffusion, inertia and interception mechanisms on particle trap. With increasing cell density, wall thickness, diameter and length of filters, the filtration efficiencies of different size particles ascend with different extents. The trap efficiencies rapidly increase with decreasing porosity and mean pore size of filter substrates. These results are valuable for matching DPF structural parameters and improving filtration performance of DPF.

Key words: Filtration performance  Filter  Structural parameter  Particle size  Particulate matter  Diesel engine

CLC No: TK421.5 U464.1

上海市科技攻关计划(053012009)、中国博士后科学基金(2005037151)、上海市博士后科研基金(06R214151)、内燃机燃烧学国家重点实验室开放基金(200706)、国家科技攻关计划(2005BA413B13)和上海汽车工业科技发展基金(0408)资助项目. Received 20070312, received in revised form 20070929