建筑结构屋面常用玻璃的太阳辐射特性试验研究

Solar Radiation Characteristics of Commonly-Used Glass on Building Roof

双层中空玻璃广泛应用于大跨结构的屋面结构,其太阳辐射透射系数影响建筑钢结构的热环境.通过试验研究了透明玻璃、福特蓝膜、蓝星灰膜、绿色玻璃、蓝星灰玻共16种双层中空玻璃的透射系数特性.根据玻璃下钢板的温度,计算钢板表面的太阳辐射强度,通过与空白对照组的比较,得到不同时刻玻璃的太阳辐射透射系数.根据菲涅耳公式提出的透射系数与入射角的关系,推算得到玻璃的透射率.为了简化计算,提出了简化的菲涅耳公式和玻璃折射常数k.结果表明:透明玻璃的透射率可达80%,以上,蓝星灰玻、蓝星灰膜和绿色玻璃透射率在50%,左右,福特蓝膜型玻璃的透射率在35%,左右;试验得到玻璃的透射率随玻璃厚度的增大略微有所减小,符合光学理论;双层中空玻璃夹层空气厚度对玻璃透射率没有明显影响;不同时刻太阳的辐射角度不同,得到的玻璃透过系数就不同,透过系数随太阳入射角的减小而增大.

The double-layer hollow glass is widely used on the roof of the large-span structure,and its solar radiation transmission coefficient has an effect on the thermal environment of the building.In this paper,experiment is carried out to explore the transmission coefficient of16different types of hollow glass such as clear glass,Futelanmo glass,Lanxinghuimo glass,etc.According to the temperature of steel plate under the glass,the solar radiation intensity on the surface of the glass can be calculated.And comparing with the counterpart of the blank control group,the solar radiation transmission coefficients at different times can be obtained.Based on this,the transmissivity of glass could be obtained according to the Fresnel formula which illustrates the relationship between the transmissivity and the angle of incidence.In order to simplify the calculation,the simplified Fresnel formula and refraction constant k are given.Results show that the transmissivity of clear glass can be more than80%,while it is around50%,for the Lanxinghui glass,Lanxinghuimo glass,and green glass,and around35%,for the Futelanmo glass.The transmissivity decreases with the increase of the glass thickness in this experiment,which conforms to the optical theory.The thickness of air between the two glass layers show no obvious effect on the transmissivity.The transmissivities obtained are different with different solar radiation angles,and the transmissivity increases with the narrowing of the angle.