【作者】 许婕；

【导师】 亢燕铭；

【作者基本信息】 东华大学 ， 供热、供燃气、通风及空调工程， 2008， 硕士

【摘要】 随着人们在室内时间的增加和对室内环境要求的提高,使用空调系统提供良好的热舒适性和室内空气品质变得越来越重要。置换通风作为一种新的通风方式,与传统的混合通风相比,在许多场合具有明显的优势。但在我国,有关置换通风室内颗粒污染物输送方面的研究还非常少。因此,本文将采用数值预测的方法,对置换通风房间中的气流运动和颗粒物分布规律进行了研究和分析。本文针对采用置换通风系统的典型办公室,分别就室内不同的颗粒污染物分布位置、不同送风温度以及送风口布置方式等工况进行了模拟计算。对比分析这些因素对室内流场的影响,研究它们对颗粒物浓度场的影响规律。文中就颗粒物在室内呼吸平面沿房间开间和进深方向的变化特征展开了详细地分析研究。研究结果表明,置换通风方式下,不同污染源高度对室内颗粒物浓度分布影响很大,污染源在接近地面高度时,室内呼吸高度上的颗粒物浓度较低,而污染源分布位于较高处时,在室内呼吸高度上的浓度较高,对室内空气环境的影响不容忽视。模拟结果还发现,不同送风参数对室内颗粒物浓度分布影响显著。大温差送风工况相对于小温差送风来说,颗粒物在室内呼吸高度上的开间和进深方向上浓度大多数情况下小于小温差情况。因此,对室内人员的危害相对较小。此外,通过对比两种送风口布置方式下的浓度分布结果可以发现,不同位置颗粒污染源释放出来的气溶胶粒子在不同送风口布置方式下也呈现出了不同的分布特性,粒子源位于无热源区域时,风口竖放下的室内空气质量略优于风口横放,而污染源位于近送风口热源区和远送风口热源区域时,风口竖放时的室内空气质量明显差于风口横放时的空气品质。更多还原

【Abstract】 As people spend more time indoors, heating, ventilating and air-conditioning systems that provide high thermal comfort and indoor air quality become more and more important. Compared with the traditional mixing ventilation, displacement ventilation, as a new type of air-conditioning strategy, has showed remarkable advantages on many occasions. However, in China, the research and application of this system is still in beginning up to now, especially in the aspect of indoor particle dispersion. So the numerical simulations are carried out in the present paper to investigate and analyze the airflow and particle dispersion in a displacement ventilated room.A typical office room with displacement ventilation was used as research object. Simulation is performed to study the change of contaminant sources locations, in-air temperature and positions. The impact of these factors on indoor airfield was compared and analyzed to make further research on particle concentration distribution. The characteristics of particle concentration variations in room length and width at breathing zone are also investigated in detail. Numerical results show that the height of pollutant source has great influence on indoor particle concentration. When the pollutant source is located around floor, particle concentration in the breathing zone is relatively low; however, when pollutant source is located at taller place, the particle concentration in the breathing zone is much higher which can’t be negligible.In addition, it can be seen that various supply parameters have great effects on indoor particle distribution. Contrast to the case of lower supply temperature difference, Particle concentration under higher supply temperature difference system in room length and room width at breathing zone is smaller. So it will result in lower risk to human health. It also can be concluded that particle dispersion characteristics under two diffuser location type is obviously different. When the contaminant source is located at none-heat source area, Vertical diffuser supply system has appreciably better indoor air quality, on the opposite, when the contaminant source is located at near-inlet area and away-inlet area, indoor air quality under vertical diffuser supply system was much worse than the case of horizontal diffuser supply system.更多还原