李冰 单炜

摘 要：针对现有车辆排气系统净化效率较低，无法有效改善车辆运行期间带来的空气污染、噪声污染等现象，本文提出复合等离子体技术与纳米光催化技术的车用消声器优化设计，并利用有限元分析软件进行优化后消声器流场及耦合振动特性分析。仿真结果表明：尾气气流对消声器的振型影响不大，且主要影响集中在低频区;耦合前后，主消声器主要振型皆为摆动和扭转，且整体没有出现明显气阻现象。通过试验进行复合等离子体与光催化净化技术的车用消声器声学性能和净化性能测试，试验结果表明：复合等离子体与光催化净化技术车用消声器在0～5 000 Hz 频段内，消声器整体插入损失为17 dB，整体消声效果良好;在等离子体与光催化协同净化的作用下，其NOx的净化效率最小为20.51%，最大净化效率可达47.76%，并且NOx质量分数在怠速状态可下降至0.74×10-6。这表明基于复合等离子体与光催化净化技术的车用消声器实现了系统良好的消声性能和净化性能。

关键词：车用消声器;等离体子净化;纳米光催化净化;数值模拟;消除声音的性能;净化性能

中图分类号：S776.26 文献标识码：A 文章编号：1006-8023（2021）06-0135-08

Abstract：In view of the existing vehicle exhaust system purification efficiency is low， and cannot effectively improve the air pollution， noise pollution and other phenomena during the operation of the vehicle， the optimum design of vehicle muffler based on composite plasma technology and nanometer photocatalysis technology is presented in this paper， and the flow field and coupling vibration characteristics of the optimized muffler are analyzed by using finite element analysis software. The simulation results show that the exhaust gas has little influence on the vibration mode of the muffler， and the influence is mainly concentrated in the low frequency region. Before and after coupling， the main vibration modes of the main muffler are swing and torsion， and there is no obvious gas resistance. Finally， the acoustic performance and purification performance of the vehicle muffler using the composite plasma and photocatalytic purification technology are tested. The test results show that the overall insertion loss of the vehicle muffler is 17dB in the frequency band of 0～5000Hz， and the overall noise elimination effect is good. Under the synergistic action of plasma and photocatalysis， the minimum and maximum purification efficiency of NOx is 20.51% and 47.76%， and the NOx concentration can be reduced to 0.74×10-6 at idle speed. It shows that the muffler based on composite plasma and photocatalytsis purification technology has achieved good performance of noise elimination and purification.

Keywords：Vehicle muffler; plasma purification; nanometer photocatalysis purification; numerical simulation; eliminate noise performance; purification performance

0 引言

隨着我国汽车保有量的增加，汽车在给人们的生活带来便利的同时也带来了严重的社会问题，比如大气污染、汽车噪声污染和能源紧缺等。目前针对车辆尾气排放治理的主要方法还停留在传统的改进可燃混合气的品质、改进燃烧室结构、优化进气配时以及采用三元催化转换器、废气再循环系统等。……