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绝热材料内部添加反射屏是实现高温绝热的有效方法和手段,主要通过数值模拟研究绝热材料与反射屏组成的多层绝热系统的传热特性。采用能量守恒定律和双通量方程近似法建立多层绝热系统的辐射导热耦合换热模型,通过方程的离散化数值求解,在保证绝热层低温侧温度不变的情况下,分析反射屏发射率,反射屏数目,绝热材料消光系数,绝热材料气固耦合导热系数等参数对高温绝热层厚度的影响特性。研究结果表明,绝热材料消光系数越小,材料气固耦合导热系数越小,反射屏发射率越小,则反射屏对绝热层绝热效果的影响越显著,该文的研究对于多层高温绝热层的设计具有指导作用。
The reflective screen added inside the insulation material is an effective method and means to achieve high temperature thermal insulation. The heat transfer characteristics of the multilayer thermal insulation system composed of the insulation material and the reflective screen are mainly studied through numerical simulation. Based on the law of conservation of energy and the approximation of the two-flux equation, the radiation heat-conduction coupled heat transfer model of a multilayer thermal insulation system is established. By numerical solution of the discretization of the equation, the emissivity of the reflective screen , The number of reflective screen, the extinction coefficient of insulation material, the thermal conductivity of gas-solid coupling of insulation material and other parameters on the thickness of high temperature insulation layer. The results show that the smaller the extinction coefficient of the thermal insulation material, the smaller the thermal conductivity of the material is and the smaller the reflection of the reflective screen, the more significant the effect of the reflective screen on the thermal insulation effect of the thermal insulation layer. The design has a guiding role.