高速空调客车车内粉尘分布特性分析

发布时间：2018-02-12 12:45

本文关键词： 高速空调列车粉尘浓度分布数值模拟计算流体力学　出处：《西南交通大学》2012年硕士论文　论文类型：学位论文

【摘要】：高速列车为人们出行带来便利,显著地缩短了人们的出行时间。由于生活水平的不断改善,人们对健康与舒适的诉求使得对空气质量的要求越来越高,高速空调车内的空气质量同样如此。因此,无论是列车的设计人员还是乘客都越来越关注车内空气流场的质量。粉尘的危害在近年来倍受关注,大气环境的粉尘状况令人堪忧,对于相对密闭的高速空调列车,粉尘随新风入口的进入会给客室内空气质量带来影响,所以深入分析研究列车在高速运行状态下车内流场的粉尘分布是相当必要的。本文采用流体力学中应用最广泛的数值计算方法有限体积法,基于三维、可压缩、粘性流体的N-S流体流动控制方程,k-ω两方程湍流模型以及拉格朗日法离散相模型(DPM),对高速空调客车车内粉尘的分布情况进行分析。首先,研究了列车以350km/h的速度运行时粉尘在车内流场的分布状况以及流场内粉尘分布的影响因素；其次,对不同车外空气环境下客室内粉尘的浓度进行研究,并加入滤网对其进行过滤,对比室内空气质量标准的粉尘浓度参数给出各外界环境下列车滤网参数的推荐值；最后,对不同标准的粉尘浓度要求做了对比,探讨列车车内粉尘控制的方法。计算结果表明：车内粉尘分布受车内流场的紊流强度影响,紊流扩散效应使粉尘分布更加均匀。粉尘在送风口较多的乘客区分布较均匀,而在座椅下、车厢边角处等区域产生堆积。粉尘平均浓度随时间不断增大,900s后逐渐趋于平缓,加装滤网后使浓度显著下降,列车在350km/h的速度下运行时,外界环境空气质量为一、二级时车内空气的可吸入颗粒物含量达到室内空气质量标准,而外界环境空气质量为三级时车内可吸入颗粒物含量超标。选取筛分粒径处于粉尘颗粒群分布的质量中位径附近的滤网过滤效率高。为达到室内空气质量标准规定的粉尘浓度值,外界环境空气质量一、二级时应选取目数为1250的滤网进行过滤,三级时应选取目数为2500的滤网进行过滤,滤网参数的选取应使达到过滤效果的前提下尽可能的减小滤网压降对车内流场的影响。为达到高速空调列车的乘车舒适性以及乘客的健康需求,可通过对粉尘进行多种过滤方式过滤以及对送风方式进行改进,以到达对客室内粉尘的控制。
[Abstract]:High-speed trains bring convenience to travel and significantly shorten travel time. Because of the continuous improvement of living standards, people's demands for health and comfort make the demand for air quality higher and higher. The same is true of air quality in high-speed air-conditioned vehicles. Therefore, both train designers and passengers are paying more and more attention to the quality of the air flow field inside the vehicle. Dust hazards have attracted much attention in recent years, and the dust situation in the atmospheric environment is worrying. For a relatively closed high-speed air-conditioned train, dust with the entrance of fresh air will have an impact on the air quality in the passenger room, so it is necessary to analyze and study the dust distribution in the flow field of the train getting off at high speed. In this paper, the finite volume method, which is the most widely used numerical method in fluid mechanics, is based on three-dimensional, compressible, The turbulent model of the N-S fluid flow control equation of viscous fluid and the Lagrange discrete phase model are used to analyze the distribution of dust in high-speed air-conditioned passenger car. The distribution of dust in the flow field and the influencing factors of the dust distribution in the flow field are studied when the train is running at 350 km / h. Secondly, the concentration of dust in the passenger room under different air conditions outside the vehicle is studied. The filter screen is added to filter it, and the recommended values of train filter screen parameters are given by comparing the dust concentration parameters of indoor air quality standards. Finally, the requirements of different standards for dust concentration are compared. The method of dust control in train is discussed. The results show that the dust distribution in the vehicle is affected by the turbulence intensity of the flow field inside the vehicle. The turbulent diffusion effect makes the dust distribution more uniform, and the dust distribution is more uniform in the passenger area with more air outlets, but under the seat. At the corner of the car, and other areas, the dust concentration gradually leveled off with the increase of time, and the concentration decreased significantly after installing the filter. When the train was running at a speed of 350 km / h, the ambient air quality of the outside environment was one. At the second stage, the content of inhalable particulate matter in the air in the vehicle reaches the indoor air quality standard. However, when the ambient air quality is third grade, the content of inhalable particles in the vehicle exceeds the standard. The filter screen with sieve particle size near the median diameter of dust particle group distribution has high filtration efficiency. In order to meet the indoor air quality standard, the filter screen has high filtration efficiency. Determined dust concentration, The air quality in the outside environment should be filtered by the filter screen with 1250 mesh number at the second stage, and the filter screen with 2500 mesh number should be selected for filtering at the third level. The selection of filter screen parameters should minimize the influence of filter pressure drop on the flow field of vehicle on the premise of filter effect. In order to achieve the ride comfort of high-speed air-conditioned train and the health needs of passengers, In order to control the dust in the guest room, we can filter the dust by many kinds of filter and improve the way of air supply.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R128

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