海面反射特性对海岛建筑空调负荷影响研究

Study on the Influence Law of Sea Reflection Characteristics on Building Air Conditioning Load in Island-reef Areas

为探究海域岛礁建筑在强辐射条件下海面下垫面反射特性对建筑的影响规律,本文基于Cox-Munk粗糙海面反射模型,分析了海面下垫面半球反射率在不同风速及太阳高度角下的变化规律,进而探讨了永暑礁年平均风速下海面反射对建筑各朝向辐射能、室外空气综合温度、日射得热因数及建筑空调负荷的影响规律。结果表明:日逐时海面半球反射率呈U字型,风速/太阳高度角越大,海面平均/逐时半球反射率越小;永暑礁年平均风速下的海面平均半球反射率为0.167;由于海面反射,建筑各朝向总太阳辐射强度增值均大于60 W/m^2(10:00-15:00),室外空气综合温度增值均在1℃以上(9:00-16:00),日射得热因数最大值增值为22 W/m^2;针对本文建筑模型、围护结构构造及材料热物性参数,考虑/不考虑海面反射,永暑礁冷负荷指标分别为26.40 W/m^2和23.23 W/m^2,相应的冷负荷指标修正因子约为1.05。该研究可为我国海域岛礁地区建筑空调设备的合理选型提供依据。

In order to explore the influence law of sea reflection characteristics on island-reef building, this paper adopted the "Cox-Munk" rough sea reflection model to analyze the change rules of sea hemisphere reflectivity under different wind speeds and solar altitude angles, then discussed the influence function of sea reflection characteristics under annual average wind speed in Yongshu Reef on solar radiant energy, outdoor air synthetic temperature, solar heat gain factor and building air conditioning load. The results indicated that the daily sea hemisphere reflectivity showed U-shaped, and as wind speed/solar altitude angle increased, the sea average/hourly hemisphere reflectivity reduced. The sea hemisphere reflectivity under annual average wind speed of Yongshu Reef was 0.167. Owing to sea surface reflection, the value-added for total solar radiation intensity and outdoor air synthetic temperature of each direction was respectively more than 60 W/m2 (10:00-15:00) and 1 ℃(9:00-16:00), and the maximum value of solar heat gain factor magnified 22 W/m^2. Aiming at building model, structure and thermal properties of building envelop appeared in this article, the cooling load index for Yongshu Reef was severally 26.40 W/m2 and 23.23 W/m^2 with/without considering sea reflection, and the corresponding correction factor was about 1.05. This study can provide basis for the reasonable selection of air conditioning equipment in island-reef areas.