微粒捕集器压降特性理论与仿真分析

摘要

对DPF的压降特性进行了理论和仿真分析，阐明了压降产生的机理，指出DPF的压降主要由可视为多孔介质的载体壁面和炭烟层及载体的入口通道和出口通道的摩擦造成，且压降历程与炭烟捕集过程相似，分为3个阶段。在深床过滤阶段，载体壁面渗透率随炭烟的积累迅速减小，DPF压降迅速增大，当壁面达到饱和时，饼状层单独起到捕集炭烟的作用，且炭烟层的渗透率保持不变，DPF压降上升趋缓。由壁面带来的压降占压降的绝大部分。%The theoretical and simulation analysis of DPF pressure drop characteristics were carried out and the mechanism of pressure drop was clarified .It was pointed out that the pressure drop of DPF was the result of the gas flow blocked by the multi-hole carrier wall ,soot layer and inlet and outlet channel .Similar to the process of soot collection ,the process of pressure drop consisted of three phases .In the phase of deep bed collection ,the wall penetration rate decreased rapidly with the accumu-lation of soot and the pressure drop of DPF increased .When the wall reached the saturation ,the cake-shaped layer collected the soot alone ,the penetration rate of soot layer kept the same and the pressure drop increased slowly .The pressure drop caused by the wall accounted for the main part .