柴油机DPF孔道气相流场及噪声特性分析  

Analysis of Gas Phase Flow in Channels and Its Noise Characteristics for a Diesel Engine DPF

作　　者：李冰[1] 李靓雪 陈贵升[1] 周群林 孙富贤 黄震 Li Bing;Li Liangxue;Chen Guisheng;Zhou Qunlin;Sun Fuxian;Huang Zhen(Yunnan Key Laboratory of Internal Combustion Engine,Kunming University of Science and Technology,Kunming 650500,China)

机构地区：[1]昆明理工大学云南省内燃机重点实验室,云南昆明650500

出　　处：《内燃机学报》2021年第3期265-272,共8页Transactions of Csice

基　　金：国家自然科学基金资助项目(51866004).

摘　　要：利用数值模拟(CFD)软件建立柴油机微粒捕集器(DPF)孔道三维模型,对孔道内气体流动情况进行计算;通过建立加装DPF的一维整机仿真模型,结合孔道流场分布特性,分析不同转速工况下DPF载体及加载不同碳烟量对其噪声特性的影响.结果表明:各入口流速下,流速分布在DPF进气孔道内呈现从中心径向递减、从始端轴向递减趋势,且后段出现波纹状流速突变区;排气孔道流速分布趋势与进气孔道相反;进气孔道内压力分布相对均匀;排气孔道前中段压力分布较均,在低流量下中后段呈轴向递减趋势,高流量下在后段出现骤增.高转速工况下DPF气动再生噪声量大于低转速工况;深层碳烟在较高转速工况下对DPF噪声的影响更显著,A计权声压级降幅可达2 dB以上;碳烟饼层在较低转速工况下对DPF噪声特性影响更大.A 3D model of diesel particulate filter(DPF)channel was established and the gas flow in the channel was calculated.A one-dimensional thermodynamics model of the engine with DPF,combined with flow field distribution characteristics in the channel,was used to analyze the influence of the DPF carrier and different soot loads on its noise performance under different rotating speed conditions.The results show that at each inlet velocity,the velocity distribution in the DPF inlet channels decreases radially from the center and axially from the beginning end,and an abrupt transition zone of corrugated velocity appears in the rear section.The distribution trend of velocity in outlet channels are opposite to that in inlet channels.The pressure distribution in the inlet channels is relatively uniform.The pressure distribution in the front middle section of the outlet channels is relatively uniform,showing an axial decreasing trend at low flow rate in the middle and rear section and a sharp increase at high flow rate in the rear section.At higher engine speed,the noise quantity of DPF pneumatic regeneration is higher than that at lower engine speed.The influence of deep soot on DPF noise is more significant at higher engine speed with a decrease of more than 2 dB.The influence of soot cake on DPF noise is greater at lower engine speed.

关 键 词：柴油机微粒捕集器 孔道 流动 噪声 碳载量 

分 类 号：TK422[动力工程及工程热物理—动力机械及工程]