可焓变纳米隔热材料的数值模拟和试验研究  

Numerical and Experimental Investigations on the Nanoporous Insulation Material with Enthalpy-change Component

作　　者：肖鹏[1] 孙陈诚[1] 吴文军[1] 李俊宁[1] 王俊山[1] Xiao Peng;Sun Chen-cheng;Wu Wen-jun;Li Jun-ning;Wang Jun-shan(Aerospace Research Institute of Materials&Processing Technology,Beijing,100076)

机构地区：[1]航天材料及工艺研究所,北京100076

出　　处：《导弹与航天运载技术》2022年第4期80-85,共6页Missiles and Space Vehicles

摘　　要：在纳米隔热材料中增加相变或热解吸热的可焓变组分,可以显著增加纳米隔热材料的吸热能力,提升飞行器热防护结构的隔热时长。针对纳米隔热材料的孔隙内焓变量以及产物动态扩散速率难以准确测量的问题,开展了基于分子动力学的纳米孔隙内焓变与传输过程的仿真计算与样件测试,分析纳米孔隙的尺度对焓变过程的影响。结果显示,小孔径(小于4nm)的孔隙会对显著影响相变产物的聚集态和产物扩散行为,提升相变产物由固态/液态到气态的相变点和对水蒸气的阻碍作用。同时纳米隔热材料的热导率与石英灯背温测试结果显示,存在可焓变组分的最佳粒径,使隔热性能达到最优,为进一步提高纳米隔热材料的隔热性能提供了一种思路和方法。The addition of phase change or pyrolysis materials as enthalpy-change component can remarkably promote the heat absorbing performance and the thermal insulation duration time of the aerocraft.To solve the issue of measuring enthalpy change and product dynamic diffusion rate in nano holes of nanoporous insulation material,the enthalpy change and product dynamic diffusion processes are numerically investigated by molecular dynamics simulation method,for analyzing the effects of diameter of nano-pores on the enthalpy change phenomenon.The simulation results show that the small nano-pores smaller than 4nm can significantly change the product condensed state and its diffusion behavior.The small nano-pores(<4nm)can hinder the diffusion of water vapor and promote the the enthalpy-change temperature in nano-pores.Meanwhile,the results of thermal conductivity test and quartz lamp heating test indicate that,there is a optimal diameter of nano-pores to achieve the best thermal performance.The idea and method for further improving thermal insulation performance of nanoporous insulation material are provided.

关 键 词：纳米隔热材料 焓变 分子动力学 

分 类 号：TB34[一般工业技术—材料科学与工程]