基于保温性能的磷石膏空腔楼盖内空气层研究

Research on the Air Layer in the Interior of the Fabricated Hollow-ribbed Floor Based on Thermal Insulation Property of Phosphogypsum

空腔模盒内空气层的存在使得磷石膏空腔楼盖具有较大的保温隔热潜力,常规厚度的空气层对于空腔楼盖的保温性能提高不大。通过对磷石膏空腔内空气对流情况进行分析,确定了磷石膏空腔内空气对流的数学模型。根据Ostrach给出的对流临界Ra数,结合贵阳市冬季气候条件,将傅里叶定律运用于平壁,确定了保温条件下常规尺寸的磷石膏空腔模盒内不发生对流换热的最优空气层厚度为0.02 m,改良了磷石膏空腔模盒。最后运用Fluent软件模拟,验证该工况下空腔内对流换热难以展开。

The air layer in the cavity box greatly improves the thermal insulation of fabricated hollow-ribbed floor made of phosphogypsum while the air layer with routine thickness isn＇t good to improve the thermal insulation of fabricated hollow-ribbed floor The mathematical model of air convection in the cavity of phosphogypsum was determined by analyzing the air convection in the cavity of phosphogypsum. According to the convection critical Ra number given by Ostrach,the Fourier law was applied in plane wall,together with the winter climate in Guiyang to determine that the optimum air layer thickness without convection heat transfer in conventional cavity mold box under thermal insulation conditions is 0.02 m. So the cavity mold box was upgraded. Finally,FLUENT was simulated to prove that the convection heat transfer was unavailable under the working condition.