【作者】 褚淑祎；

【导师】 陈建孟；

【作者基本信息】 浙江工业大学 ， 环境工程， 2006， 硕士

【摘要】 在生物过滤系统中，受微生物代谢活动、气流特性以及填料特性的影响，填料床存在明显的热质迁移现象，使系统宏观运行不稳定。本文主要建立了生物过滤系统填料层热质迁移过程的数学模型，考察了一维情况下填料层温度和湿度的变化情况，以及气流特性对填料层湿度的影响，为生物滤床废气处理系统的工程设计提供了参考依据。参考多孔介质的体积平均模型和三参数模型，以流体质量和能量守恒方程为基础，建立了微体积单元中的质量和能量守恒方程，采用Galerkin有限元法，对生物滤床处理H₂S废气过程的一维热质迁移模型进行了数值计算，并与实验数据进行了比较。结果表明，模型计算值与实测点的温、湿度值吻合良好，其相关系数都达到0.9以上。气流特性与填料层湿度变化的数值模拟显示：随着进气气速增加、相对湿度减小、温度增加、浓度增大，填料层的湿度下降，且填料层湿分迁移速率与气速呈对数关系，与温度、浓度呈指数关系，与相对湿度呈负乘幂关系；H₂S计算浓度值沿轴向由下而上逐渐降低，且随着时间的推移，轴向各点的H₂S浓度逐渐增大。去除率、去除负荷和微生物相对活性随着填料层湿度的下降而减小。更多还原

【Abstract】 There was heat and mass transfer in the biofilter media, as a result of microorganism metabolism activity, the properties of air flow and those of packing material, which made the system run unstable. The aim of this research was to develop a model for heat and mass transfer in a biofilter, and to investigate the migration of temperature and moisture under one-dimensional condition with an emphasis on factors affecting the moisture migration, so as to provide adequate data for the design and operation of a full-scale biofilter system.Firstly, a heat and mass transfer model was set up based on porous media volume-averaging model and three-parameter model. The operator splitting algorithms and the finite element method developed by Galerkin were adopted to deduce the discrete equations. The numerical values of one-dimensional model for heat and mass transfer of media in a biofilter system for the treatment of hydrogen sulfide were in good agreement with the experimental data, and all of the correlation coefficients are above 0.9.Secondly, the effects of air flow properties on moisture migration were investigated numerically. The results confirmed that the rate of moisture transportion was in proportion to the logarithm of gas velocity, exponential of temperature and concentration, and negative power of relative humidity, and in the relative order of gas velocity＞temperature＞concentration＞relative humidity.Finally, the effect of moisture on removal efficiency was calculated based on the model, whose result showed that hydrogen sulfide concentration decreased along the biofilter, while increased as time passed. Both the removal efficiency and elimination capacity decreased as moisture of the media decreased. The microbiological relative activity, calculated as the maximum decomposition rate equal to one, increased as moisture of the media increased, and it tended to be one when the moisture was 60%.更多还原