冬季自然通风与室内污染物的迁移特性

Natural ventilation in winter and migration characteristics of indoor pollutants

为研究冬季自然通风条件下室内污染物的分布及迁移规律,以非稳定传热方法确定了建筑围护结构的等热流边界条件,在此基础上,采用FLUENT中的Realizable k-ε湍流模型对兰州地区某住宅内的污染物浓度场进行了数值分析。结果表明:通过围护结构的耦合传热过程使得室内不同房间污染物浓度场的时空分布存在较大差异,房间整体通风效率随通风时间延长呈逐渐下降趋势;在51 min的通风期间,工况10、11、12的通风效率均在95%以上,而"双进口、单出口"的工况12通风效率达到了97%以上;综合考虑室内采暖温度、污染物浓度限值以及室内竖向温差,最终确定了工况12为最佳通风模式。

To study the profile of indoor pollutants and their migration characteristics under natural ventilation in winter, in this study, we adopted the realizable k-εturbulent model of computational fluid dynamics （ CFD） to nu-merically analyze the pollutant concentration field in a Lanzhou residence. We used the unsteady heat transfer meth-od to obtain the wall boundary condition of the uniform heat flux. The results indicate that the pollutant concentra-tion profiles in different rooms differ significantly with respect to the coupled heat transfer through the building enve-lope. The average ventilation efficiency decreases with increasing ventilation time. During a ventilation time of 51 minutes, the ventilation efficiencies of cases 10, 11, and 12 were all over 95%, and the ventilation efficiency of case 12, which had two inlets and one outlet, was over 97%. By simultaneously considering the differences in heat-ing temperature, pollutant concentration, and indoor vertical temperature, our study results show that case 12 is the optimum ventilation mode.