严寒地区住宅通风换气参数的研究

严寒地区节能住宅执行外窗气密闭性等级6级标准后,提高了室内的气密性,降低了冷风渗透能耗。但是,同时降低了室内空气质量和舒适度。因此,采用有组织的通风换气对于提高室内空气质量,营造健康舒适的室内环境非常必要。本文研究了严寒地区住宅建筑冬季室内通风换气的现状,提出了改善住宅建筑冬季室内通风换气的技术措施,确定了冬季室内通风换气的主要参数取值方法,给出了严寒地区住宅通风换气装置的运行调节模式。对严寒地区住宅建筑的冬季通风换气设计及其系统运行具有一定指导作用。     

耦合风压和热压的中庭建筑自然通风模拟分析

建立一个简化的中庭建筑模型,利用Airpak软件模拟单独风压作用和耦合热压风压作用两种状况下的室内自然通风效果,然后分别改变窗口位置和增加室内热源强度,根据模拟计算结果,统计建筑内各房间空气换气次数,分析这几种因素对室内自然通风的影响,研究表明热压和风压共同作用时,对迎风面房间起促进作用,对背风面房间产生抑制作用,通风开口位置和室内热源强度是影响室内气流流动的关键因素。     

严寒地区住区室外风环境数值模拟研究

该文立足于优化建筑小区规划设计的理念,利用CFD软件模拟严寒地区住区在冬、夏季主导风向下的绕流风场,得到住区内人行高度处的风场分布,然后依据相关规范对小区的风环境进行了详细的分析,提出了有助于严寒地区小区规划的措施与建议.     

厦门地区单侧通风房间的窗户开口形式对室内风环境的影响研究

针对厦门地区的气候特征及自然通风条件,对该地区建筑中有代表性的单侧通风房间进行简化抽象,得到五种不同通风开口形式的单侧通风物理模型,并加入不同楼层高度这一变量,运用CFD方法对其进行模拟研究。通过分析模拟结果得出,楼层高度可影响进入室内的风速、方向以及室内风场的分布,在单侧通风模型迎风面的竖向增设通风开口可在局部或整体上提高室内通风效果并且可以增强地面除潮和室内采光效果,但仍需从构造上解决此类开口形式的防水等问题。     

一种适用于寒冷地区近零能耗居住建筑的新风系统

近零能耗居住建筑的卫生间大都采用独立的机械排风系统进行通风换气,极易导致建筑处于负压状态并造成卫生间排风能量损失。通过研究适用于寒冷地区近零能耗居住建筑高效新风热回收系统的基本特征,提出了一种新风系统,从性能设计、控制原理、运行模式、能耗特点四个方面进行了详细阐述,为近零能耗居住建筑实现室内良好的气流组织,最大限度地降低换气过程中的热损失,并解决卫生间排风造成的能量损失及室内气流组织不合理的问题提供参考。     

基于Airpak的被动房办公室地送风数值模拟研究

被动房仅依靠新风换气机实现通风和热回收,能大幅度降低建筑能耗,且办公室作为工作人员长时间停留场所,增强室内通风效果具有重要意义。本文主要研究了地送风出风口与排风口的不同数量及不同位置对被动房办公室气流组织的影响。利用Airpak软件对被动房办公室地送风进行数值模拟,得到室内气流组织的温度场及速度场,并采用PMV-PPD对室内人员热舒适性及空气品质进行了评价。在通风效果方面,对被动房办公室的地送风设计进行了优化。     

某观演建筑室内气流组织模拟

以某观演建筑为实例,建立其物理和数学模型,对建筑内气流组织进行数值模拟,给出室内速度场和温度场的分布情况.通过对不同空间位置速度和温度的等值线图和矢量图分析,找出室内气流组织不合理之处,以此指导和改进建筑室内的空调通风设计.     

模拟分析学生宿舍自然通风下不同楼层的室内环境

室内通风与热舒适性研究,是暖通专业的一个重要课题。文章采用FLUENT软件,对北京某高校学生宿舍不同楼层的室内环境进行数值模拟,比较了热压单独作用以及热压与风压共同作用时室内气流速度分布情况,证明在单独热压作用下高层宿舍通风环境优于低层宿舍,而风压的影响将使得低层宿舍通风环境恶化。通过分析宿舍不同的通风方式对室内气流组织的影响,得出3层以下宿舍不能仅仅依靠自然通风,而应结合强制送风或排风来改善室内环境品质的结论。     

窗户热损失的补充

窗户是住宅建筑围护结构的一个重要部分,它的主要作用是采光和通风。但在北方严寒地区,冬季窗户带来的热损失又是相当惊人的,住宅室内大部分热能是通过窗户散失的。冬季,由于室内温度比室外高,就会由热压引起空气渗透。另一方面由于人们的呼吸、洗衣、烧饭等活动,室内水蒸汽的含量比室外高,湿度也比室外大,这就将出现蒸汽渗透。当窗户的内表面温度达到室内空气露点温度     

严寒地区住宅建筑通风及遮阳技术方案的节能率研究

为了寻求高效降低严寒地区建筑节能技术,根据严寒地区典型住宅建筑仿真模型,深入分析了基于典型通风及遮阳的15种被动技术方案的节能率。研究结果表明,与普通自然通风相比,其他通风方式对建筑能耗的节能率并不高,仅能达到0.03%。与无遮阳相比,其他遮阳方式对建筑能耗产生负面作用,并不能节约建筑能耗。对于严寒地区典型住宅建筑,建议采用自然通风及无遮阳方式。研究成果可为严寒地区被动技术应用与管理方向提供一些参考。     

基于风速补偿的自然通风房间热舒适性模拟研究

为获得自然通风条件下室内的热舒适评价方法,利用Fluent软件,根据杭州市典型室外气象参数确定边界条件,模拟居住建筑室外绕流场、室内通风场和温度场的分布规律;运用基于风速补偿的热适应性评价模型分析室内热舒适状况,并将此法与PMV模型结果对比,表明前者定义舒适的阈值较小,且正向偏离较大,后者则能较好反映自然通风房间的热环境。     

Ventilation of air-conditioned residential buildings: A case study in Hong Kong

More and more studies reported that there were insufficient ventilation and excessive CO_2 concentration in air-conditioned residential buildings, but few solutions were provided. This study investigates the overnight evolution of CO_2 concentration in air-conditioned residential buildings and then focuses mainly on the evaluation of three ventilation strategies, including overnight natural ventilation, short-term mechanical ventilation and short-term natural ventilation. On-site measurements were conducted in a typical residential bedroom in Hong Kong in September. The indoor and outdoor CO_2 concentration, air temperature and relative humidity as well as the outdoor wind speed during the measurements were analysed. Ventilation rates were calculated based on the time series of CO_2 concentration. This study confirms that additional ventilation is usually needed in air-conditioned residential buildings. Overnight natural ventilation with even a small opening is associated with excessive energy consumption and deteriorated indoor thermal environment. Short-term natural ventilation strategies are inefficient and uncontrollable. Compared to the best short-term natural ventilation strategy, a reasonably designed short-term mechanical ventilation strategy requires only a 41% of ventilation period to complete one full replacement of indoor air and to reach a lower indoor CO_2 concentration. Nighttime case studies and a theoretical analysis suggest that a few several-minute mechanical ventilation periods could potentially maintain an acceptable indoor air quality for a normal sleeping period of 8 h.     

深圳居住建筑夏季自然通风降温实验研究

以深圳市六种布局不同、楼层不同的居住建筑为对象，调查了夏季室内热环境，测试了不同通风工况下围护结构内表面以及室内外温湿度，分析了居住建筑在夏季采用自然通风降温的可行性，比较了持续自然通风与间歇自然通风的优劣以及不同遮阳方式的遮阳效果，提出了采用自然通风降温方式的条件及建筑设计中应改进之处。     

重庆农村住宅热环境调查与能耗模拟分析

通过对重庆地区农村住宅的实地调研和对农村典型住宅室内外温度的连续监测,获得农村住宅的主要围护结构类型及典型农村住宅供暖季与空调季的室内、外热环境状况,利用重庆地区自然通风适应性热舒适性评价模型进行分析。在现有农村住宅围护结构热工性能条件下,供暖季室内温度达到舒适范围的有0 d,空调季有73 d;室内热环境状况差,冬季保温要求比夏季隔热要求更高。在供暖空调设备典型运行模式下,以调研数据为基础,借助DeST-h软件对农村典型住宅供暖空调能耗进行模拟,获得了农村住宅单位建筑面积供暖空调设备耗电量。     

广东地区农村住宅室内热环境优化研究

广东地区新建农宅有向多层发展和天井消失的趋势,室内热环境因此而变化。为了解广东地区新建农宅室内热环境现状,选取有天井现代农宅、无天井现代农宅和传统农宅各一栋进行现场实测,在对比分析的基础上发现现代农宅室内热环境存在优化的空间。针对广东地区现代农宅存在的问题,借助计算机辅助分析的手法提出适宜的优化措施,屋面遮阳、增大天窗高度及天窗开口置于下风向是改善有天井多层农宅夏季室内热环境的有效措施,无天井现代农宅通过局部架空和窗口遮阳改善室内热环境效果显著。     

Improved airflow around multiple rows of buildings in hot arid climates

This paper studies the natural wind environments in two locations of hot climate regions at Egypt. Aswan and Farafra in south and west Egypt were selected. Two proposed models are simulated by computational fluid dynamics (CFD) in two cases of wind velocities. The two models have different both of dimensions at passages and cavities between buildings and shapes of windward sides of buildings. The wide distances between passages of buildings at the same row and rectangular shapes that have slope exterior wall in two directions at the windward sides are devoted to Aswan. The narrow distances between passages of buildings at the same row and rectangular shapes that have trapezoid courtyards that face wind are devoted to Farafra. The results show that the Aswan model can achieve at the inlet surfaces (windward side of buildings) 1.8-2.4 m/s (60-80% of wind velocity) especially at the second and third rows of indoor air velocity which is the required indoor air velocity for comfort. The Farafra model which uses a courtyard can achieve at the inlet surface 1-1.2 m/s (33-41% of wind velocity) which is less than the required indoor air velocity for comfort. The results can achieve the high rate of wind velocity 38-70% and between two and three times comparing favorably with previous studies that report only 20% of wind velocity at the second row and 15% of wind velocity at the third row.     

冬季北方地区住宅建筑通风方式对比研究

随着住宅节能技术的广泛推行,对窗户的气密性要求越来越高,冬季冷风渗透远远不能满足室内人员对新风的最低需求。为了寻找节能、舒适的通风方式,本研究利用FLUENT对工程中较为常见的通风方式：自然通风方式、自然进机械排通风方式、带热交换的墙式通风器方式、带热交换的通风换气机组方式在气流组织、舒适性能、能耗特性及初投资方面进行了应用效果评价。最终得出：对于层高和装修标准较高的高级住宅中使用带热交换的通风换气机组,可以使通风系统在满足热舒适性和空气品质的基础上,更加节能,而对于一般住宅建筑,自然进机械排通风方式是相对最优选择。     

Indoor thermal environment and air quality in Chinese-style residential kitchens

This paper reviews the published literature on indoor thermal environment and air quality in Chinese-style residential kitchens (CRKs). The paper first discusses typical characteristics of CRKs, including kitchen layout, cooking methods, and ventilation systems used. Next, the paper describes the current state of the indoor thermal environment and air quality in CRKs. Finally, this paper summarizes measures to control and improve the environment inside CRKs. The results indicate that the indoor environment of CRKs is too hot in summer and exhibits a large vertical temperature difference. No appropriate model was available for accurately evaluating the thermal environment in CRKs. At the same time, CRKs are highly polluted by COx, NOx, TVOC, and particulate matter (PM). Although existing exhaust hoods could improve the indoor environment to some extent, the use of a combined exhaust, make-up air, and air-conditioning system should be considered to provide a comfortable and healthy environment in CRKs.     

Numerical simulation of inter-flat air cross-contamination under the condition of single-sided natural ventilation

The objective of this study is to investigate the mechanism of inter-flat airborne disease transmission under the condition of single-sided natural ventilation. The focus is on one of the typical designs in residential buildings with a rectangular plan layout and having a common corridor separating the two sides, each of which has a flat façade with openable windows. When the wind speed is extremely low, with doors closed and windows opened, the flats become single-sided naturally ventilated driven by buoyancy effects. The air pollutants can travel from a lower flat to a vertically adjacent upper flat through open windows, caused by indoor/outdoor temperature-difference induced buoyancy. Computational fluid dynamics is employed to explore the characteristics of this process. Based on the comparison with experimental data about the air flow distribution in and around a single-sided naturally ventilated room, the renormalization group based k?ε model, together with carbon dioxide used as a tracer, is chosen to reveal this air cross-contamination. The simulation results are in agreement with our prior on-site tracer-gas measurements, revealing that the windows flush with a flat façade can be a major route of the air cross-contamination in high-rise residential buildings. Finally, an assessment index is proposed to evaluate the potential infection risks associated with this inter-flat air flow occurring in high-rise residential buildings.     

自然通风与建筑节能

自然通风是改善室内热环境和空气品质的主要手段,热压、风压是通风形成的基本条件,合理组织自然通风能够节约建筑耗能,通过分析建筑室内通风组织的措施,为建筑师提供一定的设计依据。