车内及室内环境中材料污染物的散发传质特性研究

发布时间：2017-12-27 17:17

本文关键词：车内及室内环境中材料污染物的散发传质特性研究　出处：《北京理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：进入新世纪以来,我国的汽车业和建筑业蓬勃发展,在方便人们日常生活的同时,也造成了严重的空气污染问题。车内和室内材料散发的挥发性有机物(Volatile organic compounds,简称VOC)是造成空气品质低劣的主要原因之一。研究表明,材料VOC的散发特性由三个关键参数表征:初始可散发浓度C0,扩散系数Dm和分配系数K。测定上述散发关键参数是预测污染物散发和评估健康风险的基础。目前,散发关键参数的测定缺乏快速有效的方法,而且温度、相对湿度等环境因素对上述参数的影响规律尚不明确,难以对VOC的散发特性进行有效预测和控制。本文针对上述问题开展了研究,主要学术贡献如下:首先,建立了直流舱中材料VOC散发传质的新模型并提出了同时测定C0和Dm的浓度轨迹法。该方法先预设一个K值,再对舱内VOC浓度做线性拟合,即可根据斜率和截距获得关键参数C0和Dm。实验测定了一种典型车内材料中7种VOC的散发关键参数值,测试结果表明该方法具有较高的精度。其次,研究了环境因素(温度、相对湿度)对材料VOC散发特性的影响规律。实验结果表明,对于测试的7种VOC,C0和Dm的值随温度的升高而增大,当温度由35℃升高到50℃时,苯的C0和Dm分别增大41.9%和26.4%。而相对湿度对VOC散发关键参数的影响则有所不同,当相对湿度由50%增大到80%时,C0的值随之增大,但Dm的值有所减小。最后,推导了车内准稳态VOC浓度C与温度T和通风量Q之间的理论关系式。结果显示,当Q保持不变时,C/T0.75的对数与T的倒数呈线性关系;而当T保持不变时,C/T0.75的对数与Q的对数呈线性关系。利用文献中的数据,很好地验证了关系式的正确性。一旦关系式中的相关参数得以确定,就可以据此预测给定温度或通风量条件下的准稳态浓度值。
[Abstract]:Since the new century, the automobile industry and construction industry in our country have developed vigorously. At the same time, the problem of air pollution is also caused by the convenience of people's daily life. Volatile organic compounds (VOC) is one of the main reasons for the poor quality of air in the vehicle and indoor materials. The study shows that the emission characteristics of the material VOC are characterized by three key parameters: initial emanable concentration C0, diffusion coefficient Dm and distribution coefficient K. The determination of the key parameters of the emission is the basis for predicting the emission of pollutants and assessing health risks. At present, there is no quick and effective method to determine the key parameters. Moreover, the influence of temperature and relative humidity on the above parameters is not clear. It is difficult to predict and control the emission characteristics of VOC effectively. This paper studies the above problems. The main academic contributions are as follows: first, a new mass transfer model for material VOC in DC cabin is established, and a concentration trajectory method for simultaneous determination of C0 and Dm is proposed. The method first presupposes a K value, and then makes linear fitting of the VOC concentration in the cabin, the key parameters C0 and Dm can be obtained according to the slope and intercept. The emission key parameters of 7 kinds of VOC in a typical internal material are measured. The test results show that the method has high accuracy. Secondly, the influence of environmental factors (temperature and relative humidity) on the emission characteristics of the material VOC was studied. The experimental results show that for the tested 7 kinds of VOC, the values of C0 and Dm increase with the increase of temperature. When the temperature rises from 35 to 50, the C0 and Dm of benzene increase by 41.9% and 26.4%, respectively. The relative humidity has a different effect on the key parameters of VOC emission. When the relative humidity increases from 50% to 80%, the value of C0 increases, but the value of Dm decreases. Finally, the theoretical relationship between the quasi steady state VOC concentration C in the vehicle and the temperature T and the ventilation amount Q is derived. The results show that when the Q remains the same, the logarithm of C/T0.75 is linear with the reciprocal of T, while the logarithm of C/T0.75 is linear with the logarithm of Q when the T remains the same. Using the data in the literature, the correctness of the relationship is verified well. Once the relative parameters in the relationship are determined, the quasi steady state concentration of the given temperature or ventilation can be predicted.
【学位授予单位】：北京理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X51

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