Guidelines for Sizing Shading Devices for Typical Residential Houses in Muscat, Oman

Energy consumption of Oman＇s building sector is around 55% of the country＇s total energy demand and it has increased by 59% from 2005 to 2010. This paper investigates the potential of energy conservation in residential buildings in the city of Muscat by providing guidelines to reduce solar gain in overheated season. It aims to identify the problem of high energy consumption in modem houses and study the relationship between energy consumption and thermal performance of the building. Based on the authors＇ analysis of Oman＇s solar data, recommendations for shading devices were developed and evaluated using e-QUEST. An energy reduction of around 10% was achieved without drastically increasing the cost of construction while also taking into consideration of society＇s requirement for privacy and its concern to visually maintain cultural identity.

不同基板的GaN器件集成模块传热分析及热优化

分别对基于3种基板,即印刷电路板(PCB)、覆铜陶瓷板(DBC)及低温共烧陶瓷板(LTCC)的氮化镓(GaN)器件集成模块的传热性能进行对比分析。结果表明,DBC模块的结-空气热阻最低,较高的是LTCC模块,最高是PCB模块。在自然对流情况下,DBC模块的结-空气热阻比PCB模块低约20%,强制对流情况下低约50%。LTCC基板相对于常用PCB基板及DBC陶瓷基板优势不显著。设计制造了基于PCB基板的GaN器件降压转换器集成模块,并对其传热性能进行热仿真及实验研究。根据热仿真模型,分析了热通孔对传热的强化作用及平行布置时器件之间的间距对其传热性能的影响。结果显示通过在PCB基板上打热通孔可显著提高模块的传热性能,从无通孔变为有通孔(通孔面积为10%芯片面积),即可使模块的结-空气热阻降低12%。

夏热冬冷地区遮阳保温一体化窗户系统研究

夏热冬冷地区,夏季太阳辐射强烈,外窗得热是影响建筑供冷能耗的关键,冬季夜间相对寒冷,外窗是室内热量散失的重要通道。立足于改善窗户系统遮阳性能和保温性能,文章介绍了研发的一种遮阳保温一体化装置,并对其热工性能进行理论计算和数值模拟。研究结果表明,装置与普通双层玻璃窗结合后,窗口综合遮阳系数SCW和传热系数K均减小,东、南、西和北四个朝向的窗口综合遮阳系数SCW最小为0.26、0.26、0.19和0.39,传热系数K可减小至1.15~1.49 W/(m2·K)。

遮阳与保温一体化窗户系统及保温性能研究

在既有建筑中,窗户通常是围护结构中保温隔热性能最差的构件,是建筑节能改造的重点;直接更换高性能窗户造价高,且会影响墙体的原有构造并产生建筑垃圾。本文设计了一种用于提高窗户系统遮阳保温性能的窗户附件———遮阳与保温一体化装置,并采用防护热箱法测试了窗户系统的热阻;实验用的窗户系统为双层玻璃,遮阳与保温一体化装置安装在玻璃冷侧;实验中考虑了该装置的空腔结构、材料热阻和材料表面发射率对窗户系统热阻的影响。实验结果显示,窗户系统热阻可达到0.66~0.80(m^(2)·K)/W,是双层玻璃热阻的3~4倍,传热系数为1.05~1.23 W/(m^(2)·K)。