一种卷烟厂高架库空调系统气流组织的优化的探索

以杭州地区某一高架库为例,基于高架库的负荷分布特点以及平面布局,提出较好地满足高架库室内参数均匀性要求的气流组织形式:下部侧送+上部顶送、车间中部和上部回风,然后根据负荷分布位置的不同来分配送风量。采用CFD手段对上下层不同风量比例时的气流组织进行模拟分析,分析表明,上下层风管的设计送风量比例为:夏季为1.783:1,冬季为3.178:1,可以很好地满足室内设计要求。     

基于结构可靠性的双曲线冷却塔施工期风荷载取值及应用

针对施工期间的钢筋混凝土双曲线冷却塔塔筒结构,采用"结构可靠度的时段分析方法",以"结构在施工期内的可靠度=设计基准期内的可靠度"为前提,求出塔筒施工期风荷载的标准值,并将其用于实际工程。该成果可为冷却塔(特别是超大型冷却塔)塔筒结构的施工期验算提供依据,对规范作出相应的补充。     

抗裂剂与冷却水管协同控制金鸡湖隧道侧墙结构开裂应用研究

为了抑制金鸡湖隧道主体结构厚度为1.4 m侧墙的早期收缩裂缝,在优选原材料与配合比设计的基础上,提出了采用抗裂剂与冷却水管控温协同控制的方法来降低混凝土开裂风险,并通过理论评估与工程应用分析了该方法的可行性.结果表明:夏季高温施工时,通过使用抗裂剂与合理预埋、操作冷却水管来调控结构温升和变形,可将收缩开裂风险系数基本控...     

橡胶混凝土的含气量及其控制方法

试验研究了橡胶的粒度、掺量和粒形对橡胶混凝土含气量的影响.结果表明,混凝土的含气量随橡胶粒掺量的增加而明显增加,在橡胶粒掺量相同的情况下,当橡胶粒的粒度小于60目时,混凝土的含气量则随橡胶粒度的减小而增加.试验还表明,消泡剂能有效降低橡胶混凝土的含气量,显著提高混凝土的强度.据此,作者提出采用消泡剂来控制橡胶混凝土含气量的建议.     

Impact of placement of portable air cleaning devices in multizone residential environments

An advantage of portable air cleaners is that they can be positioned in different parts of a building and used where air cleaning is needed. This makes them a popular choice for use in residential buildings. In typical indoor particle modeling efforts, perfect air mixing and uniform contaminant concentration distribution are assumed. However, nonuniform spatial concentrations of particles are more reflective of most environments. Using experiments to validate computational fluid dynamic and particle tracking models and applying these models in numerical based parametric analysis, this paper analyzes the overall contaminant removal in a multi-room residential building. Simulations varied (1) particle size (0.74, 3.4 and 10 μm), (2) clean air delivery rate (CADR) of the air cleaner (50 m³/h and 500 m³/h), and (3) position of portable air cleaner in different rooms. The results show very large variation of the overall particle removal for different positions of portable cleaning device. In extreme cases, the effective positioning of cleaning device can result in a factor of 2.5 change in overall particle removal and, consequently, strongly affect occupant exposure to particles.     

Classroom ventilation and indoor air quality—results from the FRESH intervention study

Inadequate ventilation of classrooms may lead to increased concentrations of pollutants generated indoors in schools. The FRESH study, on the effects of increased classroom ventilation on indoor air quality, was performed in 18 naturally ventilated classrooms of 17 primary schools in the Netherlands during the heating seasons of 2010–2012. In 12 classrooms, ventilation was increased to targeted CO₂ concentrations of 800 or 1200 ppm, using a temporary CO₂ controlled mechanical ventilation system. Six classrooms were included as controls. In each classroom, data on endotoxin, β(1,3)‐glucans, and particles with diameters of <10 μm (PM₁₀) and <2.5 μm (PM_2.5) and nitrogen dioxide (NO₂) were collected during three consecutive weeks. Associations between the intervention and these measured indoor air pollution levels were assessed using mixed models, with random classroom effects. The intervention lowered endotoxin and β(1,3)‐glucan levels and PM₁₀ concentrations significantly. PM₁₀ for instance was reduced by 25 μg/m³ (95% confidence interval 13–38 μg/m³) from 54 μg/m³ at maximum ventilation rate. No significant differences were found between the two ventilation settings. Concentrations of PM_2.5 and NO₂ were not affected by the intervention. Our results provide evidence that increasing classroom ventilation is effective in decreasing the concentrations of some indoor‐generated pollutants.     

自然通风室内热舒适均匀度ADPl研究

《绿色建筑评价标准》中对自然通风时外窗的室内外风压差提出了要求,但并未考虑室内热舒适均匀度的问题.通过结合空气分布特性指标(ADPI)对天津地区过渡季自然通风室内热舒适区的确定,对不同外窗风压、房间进深及门窗组织形式进行了数值模拟计算,发现室内热舒适均匀度与室外风压、房间进深均存在比例关系,室内热舒适均匀度随室外风压的上升而下降,并给出了ADPI在不同房间进深、风压及门窗组织形式下的预测图表,供建筑师参考.     

厨房烟气对室内空气品质的影响及其改善方法

厨房烟气主要由烹调油烟和燃料燃烧产物组成,两者都对人体健康产生极大的危害。厨房烟气现有的改善方法分为烟气净化和厨房通风两大类,它们分别有着不同的实现方法和作用。最后,根据厨房烟气产生的原因,指出了应主要从控制油烟污染源、提高厨房烟气排放能力和加强厨房烟气净化能力等三个方面来改善厨房烟气对室内环境的影响。     

住宅房间空调器运行状况的调查分析

本文根据1999年夏季对北京市区42户安装空调住宅的调查结果及空调房间室温的测试数据,分析和了解住宅房间空调器的运行特点,依据热舒适理论,确定出房间空调的启动温度为29℃左右,而房间空调的控制温度则为26℃。本文的论述为住宅建筑的能耗分析以及住宅热性能的分析评价提供了基础。