涂层参数对多孔介质压降与捕集性能的影响  

Influence of Coating Parameters on Pressure Drop and Trapping Performance of Porous Media

作　　者：李志军[1] 张建华[1,2] 焦运景 杨绵松 张时杰 吕和音 Li Zhijun;Zhang Jianhua;Jiao Yunjing;Yang Miansong;Zhang Shijie;Lyu Heyin(State Key Laboratory of Engines,Tianjin University,Tianjin 300350,China;Weichai Power Emission Solutions Technology Company Limited,Weifang 261061,China;School of Mechanical and Electrical Engineering,North China Institute of Aerospace Engineering,Langfang 065000,China)

机构地区：[1]天津大学先进内燃动力全国重点实验室,天津300350 [2]潍柴动力空气净化科技有限公司,山东潍坊261061 [3]北华航天工业学院机电工程学院,河北廊坊065000

出　　处：《内燃机学报》2024年第5期447-455,共9页Transactions of CSICE

基　　金：国家自然科学基金资助项目(51976136,51576140);河北省自然基金资助项目(E2015409022);河北省教育厅科学研究重点资助项目(ZD2017201).

摘　　要：为研究涂层对颗粒捕集器(DPF)在颗粒捕集过程中效率及压降的变化情况、孔道轴向及壁厚方向的沉积情况,建立二维加膜DPF孔道模型.主要考虑颗粒拦截机理和扩散机理、涂层渗透率及厚度等诸参数,研究涂层渗透率和厚度对捕集过程的影响以及对速度增加不利影响的抑制作用.结果表明:入口速度为1 m/s时穿壁速度呈“U形”,入口速度为5 m/s和10 m/s时呈“钩形”,涂层提高进/出口孔道轴线速度的线性,降低末端穿壁速度的峰值;涂层有效提高孔壁的捕集效率并且明显缩短饱和时间,使更多颗粒堆积在孔壁表面,但涂层过低的渗透率使得压降急剧增加;厚度增加使初始捕集效率小幅增加,但无法有效缩短饱和时间,厚度为39.0/23.4μm较为适宜;厚度相较于渗透率对压降的影响较小;大部分颗粒拦截在多孔介质壁的前端,可以防止颗粒进入壁面深处所带来的永久性压降.In order to study the effect of coating on the efficiency,the pressure drop and the deposition in the pore axial and wall thickness directions during the particle trapping process of a diesel particulate filter(DPF),a twodimensional plus-film DPF pore channel model was established.The parameters of particle interception mechanism and diffusion mechanism,coating permeability and thickness were mainly considered to study the influence of coating permeability and thickness on the trapping process and the suppression of the adverse effect of increasing velocity.The results show that the inlet velocity is"U-shaped"at 1 m/s and"hook-shaped"at 5 m/s and 10 m/s,and the coating increases the linearity of the velocity of the inlet and outlet pore axis and reduces the peak velocity of the end penetration.The coating effectively improves the trapping efficiency of the pore wall and significantly shortens the saturation time,so that more particles accumulate on the surface of the pore wall,but the low permeability of the coating makes the pressure drop increase sharply.In addition,the thickness increases the initial trapping efficiency slightly,but cannot effectively shorten the saturation time.It also has less influence on the pressure drop compared with the permeability.The more appropriate thickness is 39.0/23.4μm.Most of the particles are intercepted at the front of the porous media wall,which can prevent a permanent pressure drop damage caused by the particles entering deeply into the wall.

关 键 词：颗粒捕集器 涂层 渗透率 捕集效率 颗粒沉积 

分 类 号：TK411.5[动力工程及工程热物理—动力机械及工程]