湿热地区外遮阳构件风热调节作用实测与CFD模拟研究

Research on the Effects of External Shading Devices on Wind Velocity and Thermal Environment in Hot-humid Climate Regions

外遮阳构件是湿热地区常见的建筑构件,但针对遮阳构件带来的室内自然通风与热环境影响研究仍较为缺乏。本研究结合热环境实测、热成像测量、动态流体计算(CFD)模拟等方法对一实验建筑外遮阳构件的热环境调节作用进行测试。结果显示,遮阳构件遮挡区域平均温度降低0.5~1.22℃;风速比外部风速降低1.5~1.7 m/s;黑球温度平均值降幅达6.82~8.12℃,计算MRT平均值降幅也达8.96~9.21℃。立面表面温度实测结果,南立面、西立面百叶比玻璃温度高0.9~2.8℃。对于遮阳构件的CFD模拟,显示水平百叶与50%水平遮阳构件工况对风速影响较小,对于立面设计整合较有潜力。实测与实验结果反映了外遮阳百叶对太阳热辐射、室内通风均有一定削减作用,在低风速的自然对流状态下对室内热环境具有一定调节作用。研究所采用的综合性热环境评估方法对于设计与使用后评估均有参考价值。进而,针对建筑构件尺度与室内外耦合的CFD模拟方法,对建筑立面与构造设计优化也具有借鉴意义。

Shading devices(SDs) are widely applied in hot-humid climate regions,however,the study on the effects of SDs on wind velocity and thermal environment is still lagging behind.This study tested an SDs system on an office building in Guangzhou,China through thermal environmental measurements,thermal images of building fa9ade,and computational fluid dynamic(CFD) simulations.Results reveal that the average temperature of the shading area was reduced by 0.5~1.22 ℃,the wind velocity of the shading area was reduced by 1.5~1.7 m/s compared with indoor environment.The globe temperature of test points was reduced by 6.82~8.12 ℃,and the mean radiant temperature(MRT) was reduced also by 8.96~9.21 ℃.The measurements of surface temperature(T_s) of the building fa9ade material results reveal that the temperature of SDs on the south and west was higher than that of shaded glass by 0.9 ℃ and 2.8 ℃.The CFD simulation results reveal that the horizontal SDs with 50% opening showed less effects on wind velocity,indicating great potential for facade design integration.The measurement and test results revealed that the SDs would reduce the thermal radiation and indoor ventilation to some extent,and provide the optimization on indoor thermal comfort even in a low natural ventilation situation.The comprehensive thermal environment evaluation method used can provide a reference for future design and evaluation.And the CFD simulation method for building component scale and indoor and outdoor coupling also can serve as a reference for SDs design and implications.