反射型金属保温结构热性能试验及数值分析

Thermal Performance Test and Numerical Analysis of a Reflective Type Metallic Isolation Structure

本研究应用防护热箱法原理的金属保温层热性能试验,并且基于传热学理论和数值分析方法,建立了保温层结构传热分析模型,并使用MATLAB软件编写计算程序求解模型方程组,将计算结果与试验数据进行对比,误差大都在10%以内。利用该传热模型进行敏感性分析,结果表明:金属箔层数并不是越多越好,应该合理考虑经济性及其它限制条件;热损失和导热系数随箔层间距的增加而增大,但箔层间距并非越小越好;应选择低法向反射率的金属箔,降低辐射产生的热损;热损失和导热系数随着热面温度增加而增大,基本呈线性变化。

By making use of the metallic foil structures with a low normal reflectivity to reduce the heat losses,the reflective type metallic isolation structures have been successfully used in the equipment items and pipelines in pressurized water and boiling water reactor nuclear power stations for the purpose of thermal isolation. The principles of the protective hot box method was applied to conduct a metallic isolation layer thermal performance test. Based on the heat transfer theory and numerical analytic methods,a heat transfer analytic model for isolation layer structures was established and by using the software Matlab,a calculation program was prepared to seek solutions to the equations of the model. The calculation results were compared with the test data. It has been proven that the analytic model thus established can correctly simulate the key parameters influencing the thermal performance of the isolation structures.Finally,the analytic model thus established was used to obtain the relationship curves showing the influence of the number of the metallic foil layers,metallic foil spacing,normal reflectivity of the metallic foil and temperature on the hot surface of the isolation structure on the thermal performance.