基于隔热采光性能的建筑百叶综合节能效果研究

本文兼顾隔热以及采光性能,研究了建筑百叶对室内制冷能耗和照明能耗的综合影响,并提出光热综合能耗来全面评估其节能性。依据软件模拟无遮阳、45°以及90°开启百叶三类模型在夏季典型日的制冷负荷与所需光通量,计算出建筑窗体引起的光热综合能耗。结果表明：夏季在使用光效较低的灯具时,90°开启百叶比无遮阳情况节能13%,而使用光效高的灯具时,90°开启百叶比无遮阳情况节能29%,但45°开启百叶的节能效果与其相差不大。当根据室外光热环境对百叶进行合理控制时,光热综合能耗将会更小,节能率高达40%。     

百叶型外遮阳对建筑光热能耗影响的优化探讨

为探究水平百叶外遮阳装置对室内全年照明、制冷、采暖能耗的影响，以确定装置的最优调节策略和对应节能效率，文章以上海地区某建筑为例，通过Ladybug和Honeybee分析软件，结合Energy Plus、Radiance、Daysim等模拟引擎，对无遮阳与不同百叶遮阳条件下，室内全年的制冷、采暖、照明能耗进行对比，得出三部分能耗的增减情况。然后以全年为周期，对百叶倾角进行人工调整，当全年频率为0次、2次、4次、6次、12次时，对应的室内最低光热综合能耗降幅分别为3.17%、4.16%、4.99%、4.96%、5.54%。研究从定量的角度证明水平百叶外遮阳装置可降低室内夏季制冷能耗，但也会显著增加全年照明和采暖能耗，可作为百叶遮阳装置节能调控的参考依据。     

基于综合能耗下外遮阳百叶控制策略

针对目前建筑能耗增长过快的现状,结合空调采暖能耗与照明能耗在能耗组成中占比大的事实,提出了基于综合能耗下的外遮阳百叶控制策略,深入挖掘建筑节能潜力。使用建筑设计软件Ecotect,建立郑州地区某遮阳建筑的仿真模型,分别导入采光分析软件Daysim和能耗模拟软件EnergyPlus中,模拟11种百叶倾角(15°～165°)下全年逐时照明能耗和空调采暖能耗,整理出各时刻下11种百叶倾角对应的综合能耗,取各时刻综合能耗最小值对应的百叶倾角作为动态百叶开启角度,分析得到动态遮阳下的全年综合能耗。结果表明,与常规外遮阳控制策略相比,基于综合能耗下的外遮阳优化控制策略可大幅提高建筑节能率。     

近零能耗建筑外百叶遮阳节能采光耦合特性研究

近零能耗建筑的研究是我国建筑节能低碳发展的必然趋势,而外百叶遮阳是提高近零能耗建筑能效的有效措施之一,外百叶遮阳应用于近零能耗建筑的节能采光耦合作用值得深入研究和讨论。因此,该研究通过EnergyPlus能耗模拟与Daysim采光模拟,分析并量化了我国不同气候区百叶倾角下近零能耗建筑外百叶遮阳的节能采光耦合特性,并在此基础上,给出了不同气候区近零能耗建筑外百叶遮阳综合节能(电)潜力最大的百叶倾角推荐表,填补现有建筑节能标准的空白,并为外百叶遮阳在我国不同气候区近零能耗建筑中的应用提供设计参考。     

西安地区居住建筑活动式外遮阳节能效果优化研究

文章以西安地区居住建筑活动式外遮阳为主要研究对象,通过Energy plus软件建立遮阳研究模型,分别调整外遮阳类型及构造参数,模拟出不同工况下模型的夏季空调能耗,根据模拟数据,提出适合于西安地区居住建筑的外遮阳设置策略。根据模拟数据显示,西安地区在西向房间设置横百叶遮阳能够大大降低夏季的空调能耗,同时又兼顾房间的自然采光,当遮阳特征值在1～2,百叶控制角度在30°～45°之间时,遮阳能够取得较好的节能效果。     

夏热冬冷地区窗户遮阳系统的综合能效研究

为了比较夏热冬冷地区常见窗户遮阳系统的综合能效,本文以长沙地区典型住宅建筑为例,利用Energy Plus建立模型,对光伏遮阳以及蜂巢帘、固定遮阳篷、卷帘、水平百叶窗帘等传统遮阳系统进行综合能效研究。研究内容包括光伏遮阳系统在不同方位角和不同倾斜角下的净能耗,以及其它4种传统遮阳系统在不同品质和不同布置方式下的总能耗,最后对光伏遮阳系统与传统遮阳系统的节能效果进行了比较分析。研究结果表明:南向光伏遮阳系统最佳安装角度为30°,东西向光伏遮阳系统最佳安装角度在35°到45°之间;传统遮阳系统中,蜂巢帘和卷帘节能效果最好,相比于无遮阳条件可实现节能20%以上;此外,光伏遮阳系统相比于最优的传统遮阳系统至少可以节能30%。     

夏热冬冷地区百叶外遮阳对建筑能耗及眩光的影响

以南京某办公建筑为例,采用EnergyPlus软件对南向和西向不同百叶开启度对各季节建筑能耗及眩光的影响进行了模拟。结果表明:南向外窗春、夏、秋、冬各季节百叶最优开启度分别为70°~130°,60°,60°,80°;西向外窗各季节百叶最优开启度分别为60°,40°,60°和120°;与无遮阳相比,外窗百叶在不同季节采用最优开启度时,全年总能耗的减少率南向和西向分别为13%和23%,全年眩光时间的减少率南向和西向分别为96%和94%。     

设施遮阳与绿化遮阳的节能效果对比研究

遮阳措施对于降低建筑能耗意义重大。针对成都地区1栋典型多层居住建筑,分别对水平活动百叶遮阳和垂直绿化遮阳这两种不同形式下的建筑能耗进行了计算,深入分析了节能特点,根据不同朝向对比分析了节能效果。结果表明:垂直绿化遮阳综合节能率是同等条件下水平活动百叶遮阳节能率的2~3倍,是更适用于成都地区的外遮阳设计;4个方向均设遮阳的综合节能效果优于单向设置遮阳,单向设置遮阳中南向设置遮阳最优;绿化遮阳较广的遮阳面积及其对周围气候环境的动态响应机制更利于建筑节能。     

基于能耗控制的建筑外百叶遮阳优化研究

对透过建筑外百叶遮阳进入室内的太阳辐射得热进行了分析,并以建筑全年能耗为控制指标,提出了总辐射净得益量的概念,对建筑外百叶遮阳结构(百叶倾角和百叶数量)进行了优化,对比分析了优化模型与现用模型全年节能效果。结果表明,南向百叶遮阳的效果与百叶倾角有很大关系,而东西向则不明显;总辐射净得益量概念对于综合评价遮阳设施冬夏季的节能效果具有较好的指导作用。     

寒冷地区窗口百叶外遮阳节能改造设计策略探讨

由于现代公共建筑追求美观和通透性,窗口面积越来越大,导致建筑制冷能耗增加。夏季,降低窗和玻璃幕墙的外遮阳系数可以有效降低建筑空调能耗,然而降低窗的外遮阳系数的同时也减少了对自然光的利用,因此,需要对空调能耗和室内光环境进行权衡判断。基于济南实际工程案例,运用Design Builder软件,从光和热两方面考虑,对建筑百叶外遮阳构造进行优化改造分析。结果表明,合理的增加百叶宽度或减小百叶间距,可以降低空调制冷能耗,增加室内采光均匀度。     

外遮阳百叶隔热性能与采光分析

外遮阳百叶能合理控制太阳光线进人室内,减少建筑空调能耗和人工照明用电,改善室内光环境,已成为当前追求"绿色建筑"目标的一项具体措施.该文通过理论分析和模拟,借助EnergyPlus、Radiance等软件,结合光和热两方面综合考虑,对空调时期上海地区布置不同角度和活动的外遮阳百叶办公房间的空调能耗、照明能耗及室内光环境进行了模拟、分析与比较.算例结果表明:外遮阳对照明能耗和建筑光环境的影响不容忽视;夏热冬冷地区固定式遮阳百叶的不同角度设置对建筑能耗的影响较大,其中实施活动式外遮阳措施能大幅度降低建筑能耗,有效改善室内光环境.     

铝合金百叶帘与建筑外遮阳

外遮阳铝合金百叶帘不仅可隔热、调光、反射紫外线,且耐侯性佳、轻质高强、色彩丰富,适用于新建建筑配备或既有建筑改造。是一种节能效果显著、发展前景广阔的新型建筑节能设施。     

Thermal and daylighting performance of an automated venetian blind and lighting system in a full-scale private office

Dynamic envelope/lighting systems have the potential to optimize the perimeter zone energy balance between daylight admission and solar heat gain rejection on a real-time basis, and to increase occupant comfort. Two side-by-side full-scale offices in Oakland, California were built to further develop and test this concept. An automated venetian blind was operated in synchronization with a dimmable electric lighting system to block direct sun, provide the design workplane illuminance, and maximize view. The research program encompassed system design refinements, energy measurements, and human factors tests. In this study, we present lighting energy and cooling load data that were monitored in this facility over the course of a year. Significant energy savings and peak demand reductions were attained with the automated Venetian blind/lighting system compared to a static venetian blind with the same dimmable electric lighting system. Correlations between key weather parameters and cooling and lighting were used to illustrate how the dynamic system was able to simultaneously achieve optimization between lighting and cooling end uses under the full range of weather conditions of this sunny, moderate climate. Energy efficiency estimates were conservative since experience shows that conventional daylighting control systems and manually operated shading devices are rarely used effectively in real world applications.     

南京地区活动式建筑外遮阳设施对室内热环境影响

针对活动式铝合金的外遮阳百叶帘和卷帘,对夏季和过渡季节南京地区建筑室内的热环境的影响进行了计算和分析研究,指出在该地区两种活动式建筑外遮阳设施在夏季能有效改善空调房间室内热环境,但对过渡季节自然通风房间室内热环境的影响正相反。     

Airflow and heat transfer in double skin facades

Airflow and heat transfer simulation was conducted for a DSF system equipped with a venetian blind, using computational fluid dynamics (CFD) with RNG turbulence model, for a three-level combination of slat tilt angle and blind position. The CFD prediction was validated using experimental data collected for a mechanically ventilated DSF equipped with venetian blinds. The predicted trends in glass and blind surface temperatures of the CFD model are compared well with the experimental measurements. The present study indicates that the presence of venetian blinds influences the surface heat transfer coefficients (SHTCs), the temperature and the air distribution in the DSF system. For the cases considered, the changes in the position of the blinds (outer, middle, and inner) have more effect on the distribution of temperature, velocity, and SHTCs compared to the changes in the slat angles (θ = 0°, 45°, 90°).     

Convection at the indoor side of complex fenestration systems: the ASHWAT model revisited

This paper examines the three-temperature problem of convection at the indoor side of a complex fenestration system (CFS) based on recent theoretical developments, namely the extended Newton formulation and the dQdT technique. CFD solutions were obtained for natural convection at the indoor side of various CFS configurations. The dQdT technique was then implemented numerically to obtain the paired heat transfer coefficients of each configuration. The results were used to assess the approximate relations used in the ASHRAE Window ATachment (ASHWAT) tool. The comparison shows that while there is remarkable agreement between the ASHWAT estimates and dQdT results for roller blinds, discrepancies exist between results for venetian blinds. Furthermore, although use of a delta resistor network to model convection at the indoor side is valid and relatively accurate for roller blinds, the application of this model to CFSs with venetian blinds requires additional levels of approximation. Nevertheless, the heat transfer rates calculated based on the approximate resistor-network model are in close agreement with the CFD results.     

百叶遮阳对室内光环境的影响

利用Radiance和Daysim等光照模拟软件对百叶外遮阳从照度、光照均匀度、眩光等多方面定量分析其倾角的变化对室内光环境的影响情况。选择了三个处在不同光照分区的城市分析在不同的全年光照条件下百叶遮阳不同倾角对室内全年照明能耗的影响。模拟结果显示:百叶对室内照度的影响很大,百叶遮阳在90°时,室内照度下降了70%,60°时下降了86%,30°时下降了93%;百叶遮阳的增加可以有效地提高室内照度的均匀性;晴天,百叶遮阳可以有效降低室内照度至视觉舒适度范围,阴天,其对室内照度不利,导致室内照明能耗增加;在不同光照条件下,百叶遮阳对全年照明能耗的影响不同。     

活动式建筑外遮阳设施对室内光环境的影响

针对常见的两种活动式建筑外遮阳设施,在其提供有效遮阳效果时,对建筑自然采光和室内光环境的影响进行了计算和分析研究,指出活动外遮阳百叶自然采光效果更为理想。     

Measurements and computations of ventilation efficiency and temperature efficiency in a ventilated room

In order to improve the indoor air quality in a room and to save energy, the air movement and contamination distributions in the room with ventilation have been studied experimentally and numerically. The experiment is carried out in a full-scale climate room with different air supply systems, heat gains from the venetian blinds and ventilation rates. The measurements concern room airflow patterns and air temperature, velocity and contamination concentration fields, etc. The airflow computer program PHOENICS and the cooling load program ACCURACY have been applied for the numerical simulations. PHOENICS solves the conservation equations of air mass, momentum, energy, concentration, kinetic energy and dissipation rate of kinetic energy. ACCURACY, which considers the influence of room air temperature distributions, is employed for the determination of cooling load, wall surface temperatures and convective heat transfer on room enclosure surfaces. These are the boundary conditions required by PHOENICS.The agreements between the computations and the measurements are good. The ventilation efficiency and temperature efficiency which are used for evaluation of indoor air quality and energy consumption are reported for each case. Additional application of these computations to annual energy analysis is also discussed.