摘要

The transient heat transfer characteristics of a new kind of combined multilayer thermal insulation material (MTIM) were numerically investigated in this paper. This new kind of multilayer thermal insulation is composed by silica aerogel and alumina aerogel doping with erythritol and stearic acid phase change materials. Finite Volume method combined with Enthalpy method as well as the Discrete Ordinate method is used to consider the combined conduction and radiation heat transfer with phase change problems. Based on the constructed numerical model, the transient heat transfer characteristics of the MTIM with two kinds of different arrangements were calculated and analyzed in detail. The results indicated that: (1) putting the PCMs at the bottom of the MTIM fails to enhance the thermal insulation. performance of the MTIM; (2) in contrast, putting the PCMs at the middle of the MTIM can enhance the thermal insulation performance of the MTIM successfully; (3) there is an optimum doping content of the PCMs that can lead to the lowest of the temperature of the MTIM which makes the thermal insulation performance of the MTIM to be the best.