Chimney Effect Assessment of the Double-skin Facade

The mathematic model of heat transfer through ventilated double glazing was verified with the measured data,which were from a test chamber equipped with glass face temperature,solar radiation,ambient temperature,and wind speed measurement facility.After the model validation,the double-skin facade assessment was carried out through simulation with ESP-r software integrating thermal simulation and air low net work module.The air flow situation in the air gap was analyzed on the basis of the hourly air velocity simulation data within typical winter week,summer week,spring week and autumn week.The differences of chimney effect in different seasons were discussed,and the thermal loads resulted from the ventilated and unventilated double skin facade were presented.

Ventilated Double Skin Facades in Hot-Summer and Cold-Winter Zones in China

Double-skin facades(DSF)are a technique developed for colder climates,so few people think about whether or not it can also be used for hot-summer and cold-winter zones in China.After analyzing the problems of using DSF for hot-summer zones,this paper explored on the possibility of applying DSF in hot-summer and cold-winter zones in China.The main existing research methods for DSF were also collected and commented.If properly managed,the ventilated DSF with controlled shading devices can be used even in hot summer in China.

THERMAL ENVIRONMENTS OF AN OFFICE BUILDING WITH DOUBLE SKIN FACADE

As a symbol of green architecture,double skin facade(DSF)represents a design which possesses many energy saving features,but due to the complexity of the system,the real performances and benefits have been difficult to predict.The objective of this study was to inform the applicability of DSFs,and contribute to the positive impacts of DSF designs.This study compared and contrasted energy savings in a temperate climate,where heating was the dominant energy strategy,and in a subtropical climate,where cooling spaces was the dominant issue.This paper focused on a university office building with a west facing shaft box window facade.The research method was a paired analysis of simulation studies which compared the energy performance of a set of buildings in two different climates.Simulation results showed a good agreement with measurements undertaken in the exiting building during a two-week period.The results specified that DSFs are capable of almost 50%energy savings in temperate and 16%in subtropical climates.Although these indicated DSFs are more suitable for temperate climates than warmer regions,the amount of energy savings in subtropical climates were also considerable.However,due to the costs of DSFs and potential loss of leasable floor area,investigations into other feasible ventilation options are necessary before final building design decisions are made.

Experimental study on thermal characteristics of a double skin faade building

An experimental study of the thermal characteristics of an existing office building with double skin facade DSF were conducted in hot summer daytime in Nanjing China. The temperature distributions of the DSF and indoor environment were measured at different control modes of DSF.The results show that the energy consumption of the air conditioning system in room B with opened exterior vents a closed interior facade and an air cavity with shading was 21.0% less than that in room A with closed exterior vents a closed interior facade and air cavity without shading in 9.5 h. The temperature distributions of the DSF and indoor environment in both horizontal and vertical directions were decisively influenced by shading conditions. The usage of shading devices strengthens the stack effect on the air cavity. Compared to room A the temperature distribution in room B is more uniform with smaller fluctuations.Meanwhile the problem of overheating in the air cavity of the DSF is still present in all tested conditions.

Optimisation of the double skin facade in hot and humid climates through altering the design parameter combinations

Architects welcome double skin facade(DSF)due to its aesthetic quality.The first DSF structure was intended to prevent cold weather and strong winds.Nowadays,the application of DSF under different climates has been investigated in many previous studies.Fiowever,little work had been done on the behaviour of DSF in hot and humid climates.Therefore,this paper aimed to extend the application into this specific climate and Guangzhou was selected as the sample city.Both the climate and the design influence the performance of DSF.In this paper,rather than explore how each design parameter influences the performance,the design was evaluated from an overall aspect.The Designbuilder software was used to build the single skin facade(SSF)and double skin facade base model.Annual HVAC energy consumption for both the two models was calculated and compared.An optimisation process was conducted to figure out what kinds of parameter combination could make the design more energy-saving and thermally comfortable.The results indicated that it was possible to design an energy-saving DSF system applied in hot and humid climates compared with the SSF model.The efficiency of the DSF could be further enhanced with a better parameter combination.The optimised options had some features in common,which could provide some inspirations for the application of DSF in hot and humid climates.

基于通风与火灾分析的办公建筑双层玻璃幕墙挑檐研究

随着办公建筑的快速发展,双层玻璃幕墙(double skin facade,DSF)这种新型的围护结构得到了广泛的应用,但其防火与通风性能的问题也日益凸显。因此,本研究使用Fluent和Pyrosim软件对双层玻璃幕墙进行实验分析,探究防火挑檐对烟气和通风二者的影响。结果表明,对于竖向空腔高度为三层的多楼层双层玻璃幕墙建筑而言,在防火方面挑檐宽度越宽其防火效果越好,而在通风方面挑檐宽度越小其通风率越高。因此,空腔宽度为2 m的双层玻璃幕墙办公建筑,当挑檐宽度为1.5 m时,其防火性能最优;当挑檐宽度为1 m时,同时兼顾防火与通风性能;当不设置挑檐,采用防火封堵装置时,其通风性能最优。

寒冷地区自然通风型光伏双层皮幕墙全年节能特性研究

针对寒冷地区普通双层中空玻璃幕墙、自然通风型透明双层皮幕墙(CG-DSF)和半透明光伏双层皮幕墙(PV-DSF)进行了全年建筑能耗分析,利用Energyplus软件对建筑供冷、供热、照明能耗及光伏产能情况进行模拟,并分析了新型PV-DSF幕墙结构的节能潜力.首先通过实验测量结果验证了传热模型、通风模型、发电模型和光照模型的可靠性;然后利用双层幕墙自然通风的功能,分别设定合理的通风模式进行全年能耗模拟.结果表明,相比于普通中空玻璃幕墙,CG-DSF及PV-DSF均可以降低建筑全年的空调能耗,其空调能耗分别为普通中空玻璃幕墙的60%和52%左右.耦合碲化镉半透明光伏玻璃的PV-DSF夏季供冷能耗显著降低,其年光伏发电量约为50.68 kW·h/m^(2),虽然其供热和照明能耗有所增加,但其全年总净能耗最低,比普通中空玻璃幕墙降低了46%,表现出优异的建筑节能潜力.

新型相变双层呼吸式幕墙热性能模拟研究

为解决双层呼吸式幕墙(double skin facade,DSF)自然通风效果不佳、夏季太阳辐射导致室内温度过高等问题,将相变材料(phase change material,PCM)与DSF系统有机结合,利用MATLAB数值模拟软件,探究其在不同参数影响下,PCM的相变时间和风道温升。结果显示:相变门板高度从2 m升高到6 m,PCM相变时间缩短、出风口空气温度略有升高;室外温度在10~30℃变化时,PCM相变时间从15.58 h缩短至12.92 h,出风口空气温度从0.45℃减至0.3℃;当太阳辐射量从200 W/m^(2)升至1200 W/m^(2)时,PCM相变时间由35.15 h减至7.45 h,出风口空气温度从0.15℃增至0.56℃;室内温度在10~30℃变化时,PCM的相变时间由15.77 h减至13.62 h。

温室效应和烟囱效应在双层呼吸式玻璃幕墙中实际效果验证及定性分析

温室效应对双层呼吸式玻璃幕墙热工性能存在负面影响,烟囱效应的实际效果也没有直观感受。本文对某双层呼吸式玻璃幕墙进行了一次简易热工性能实测,目的是对存在的温室效应和烟囱效应实际效果进行验证,进一步对夏季高温环境下双层呼吸式玻璃幕墙的隔热效果和原理进行定性分析。

Numerical study of thermal characteristics of double skin facade system with middle shade

Architectural shade is an effective method for improving building energy efficiency.A new shade combined with the double skin façade(DSF)system,called middle shade(MS),was introduced and developed for buildings.In this paper,a 3D dynamic simulation was conducted to analyze the influence of MS combined with DSF on the indoor thermal characteristics.The research on MS for DSF involves the temperature,the ventilation rate,the velocity distribution of the air flow duct,and the indoor temperature.The results show that the angle and position of the shade in the three seasons are different,and different conditions effectively enhance the indoor thermal characteristics.In summer,the appearance of MS in DSF makes the indoor temperature significantly lower.The indoor temperature is obviously lower than that of the air flow duct,and the temperature of the air flow duct is less affected by MS.The influence of the position of blinds on indoor temperature and ventilation rate is greater than the influence of the angle of blinds.According to the climate characteristics of winter and transition season,in winter,early spring,and late autumn,the indoor temperature decreases with the increase of the position of blinds at daytime,but the opposite is true at night.The results found in this paper can provide reference for the design and use of MS combined with DSF in hot summer and cold winter zone.

高层办公建筑立面光伏表皮设计研究现状

文章旨在探讨光伏系统在建筑立面表皮设计中的应用。首先,回顾光伏立面表皮设计的发展历程;其次,探讨光伏组件作为建筑墙体材料应用的构造设计;最后,探讨高层办公建筑在光伏立面应用方面面临的挑战,并提出未来的发展方向。文章旨在为推动光伏系统在建筑立面表皮设计上的应用提供有价值的参考。

内呼吸玻璃幕墙综合传热系数CFD模拟计算

采用CFD模拟分析了内呼吸玻璃幕墙的传热现象,比较了不同通风量以及不同幕墙宽度条件下内呼吸幕墙的综合传热系数以及百叶不同位置的遮阳效果,指出与增大通风量及幕墙宽度的方案相比,采取有效遮阳措施的内呼吸幕墙,减少围护结构热损失的效果更显著。

双层玻璃幕墙的CFD模拟与设计优化

简述了双层玻璃幕墙的节能原理。应用CFD技术对夏季简化的双层玻璃幕墙模型进行热工分析,揭示了热通道内的气流运动规律,指出双层玻璃幕墙存在的问题,并比较了几种不同设计方案的差异。最后,计算出幕墙综合传热系数和热效率两个关键参数,可为双层玻璃幕墙的工程设计提供参考。

重庆某双层皮外围护结构通风效果实测及分析

对某改造建筑的双层皮外围护结构间层通道内的冬、夏季空气温度和速度及内侧墙体壁面温度进行了实测,分析了该双层皮外围护结构在冬、夏季的通风效果,结合室内工作者在外围护结构改造前后对室内空气环境的舒适性感受,分析了该双层皮外围护结构设计上的一些问题,指出了该结构体系设计中的注意事项。

典型体型高层建筑双层幕墙风压分布试验

为了明确高层建筑双层通风幕墙的风荷载取值以及与单层幕墙的差异,分别对具有弧形和L形廊道式双幕墙的圆柱形和矩形高层建筑进行风洞试验研究,通过对内外层幕墙平均风压、脉动风压随位置及风向角的分布,以及各测点全风向角下最大正、负风压的对比分析,结果表明:廊道内任意处,外幕墙内侧和内幕墙外侧承受的风压基本一致;在整体结构抗风计算时,风荷载可按相同体型单幕墙建筑的风载取值;双幕墙内幕墙的风载可按单幕墙下的进行取值,并将偏于安全.外幕墙的风载,对圆弧的中段或L形的长边,可按单幕墙的适当折减;对圆弧的端部或L形的拐角及短边,需要进行放大.

双层皮玻璃幕墙节能研究综述及探讨

从传热机理研究、与建筑运行模式结合的研究以及全寿命周期分析三方面总结和分析了当前国内外双层皮玻璃幕墙热工性能研究的方法和成果,认为应将双层皮玻璃幕墙的设计纳入建筑设计的全过程,在不同的阶段采用不同的设计方法和工具,以便得到性能优良的双层皮玻璃幕墙。

矩形建筑双层幕墙的风荷载特征及阵风系数

采用刚性模型风洞试验和内、外层幕墙同步测压技术对矩形建筑的风荷载和阵风系数的分布规律进行详细研究,探讨了内、外层幕墙在不同气流流动区域内的风荷载大小关系.结果表明,涡脱落产生的强大吸力无论是平均风压还是脉动风压均主要作用在外幕墙上,而气流附着及气流碰撞产生的压力主要作用在内幕墙上;双层幕墙的阵风系数随测点和风向角的变化较大,平均风压越小,阵风系数越大,但对于在控制风向角下的最大瞬时风压,其内、外层幕墙的阵风系数均与规范值十分接近。根据试验结果,提出了矩形双层幕墙建筑的内、外层幕墙墙面和墙角体型系数的建议值.

夏热冬冷地区VDSF自然通风实验研究与优化

以长沙作为夏热冬冷地区的典型城市,通过试验对位于长沙地区的一已搭建好的通风式双层皮玻璃幕墙自然通风和机械通风时热通道内的流场和温度场进行对比分析.研究表明,当玻璃间距分别为0.10,0.20,0.30和0.40m时,均可实现自然通风;当玻璃间距为0.30和0.40m时,自然通风和机械通风效果十分接近.对热通道内百叶的位置进行了试验研究,发现玻璃间距为0.40m,百叶位于离外玻璃0.10m或位于热通道正中间时,自然通风和机械通风效果基本一致.结合Fluent软件分别对自然通风状态下通风式双层皮玻璃幕墙玻璃间距为0.30和0.40m,百叶位置位于离外玻璃0.10m及位于热通道正中间的情形分别进行流场和温度场的模拟对比分析.结果表明,夏季,通风式双层皮玻璃幕墙自然通风下的最佳玻璃间距是0.30m,百叶离外层玻璃0.10m.

双层幕墙性能化消防设计初探

提出了双层幕墙所带来的消防安全问题。采用计算流体力学 (CFD)方法对火焰和烟气在双幕墙结构中的传播进行了模拟分析 ,模拟分析针对两种工况 ,一种是上、下楼层设有窗槛墙的工况 ;另一种是在通风夹层内上、下楼层之间设置防火挑檐的工况。通过对模拟结果的分析 。