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采用稳态法测量高温条件下的材料热物性参数,需设计有效的热防护结构.本文设计了隔热材料和多层金属屏相结合的热防护结构,根据能量平衡方程和同心圆柱面辐射换热方程建立了热防护结构的稳态传热模型.分别讨论了隔热材料热导率、金属屏发射率、隔热材料厚度、金属屏层数对隔热结构性能的影响.结果表明:当选用碳纤维硬毡作为隔热材料,厚度105 mm,金属屏表面发射率为0.05,金属屏层数为5层,可以达到最佳隔热效果.“,”The design of an efficient thermal protection structures is essential for thermophysical property testing system at high temperature using steady state method.The combined thermal protection structures of insulation materials and multi-layer metal screens is proposed in this paper.The steady state heat transfer model of the thermal protection structures is presented based on the energy balanced equations and the radiation heat transfer equations of concentric cylinders.The effects of the thermal conductivity of insulation materials,the emissivity of metal screens,the thickness of insulation materials,the numbers of metal screens on the insulation performance for the thermal protection structures are investigated respectively.The results show that the thermal protection structures have the best insulation performance when the carbon fibrous felt is taken as the insulation materials,and when the thickness of insulation materials is 105 mm,the emissivity of metal screens is 0.05 and the numbers of metal screens is 5.