中文摘要：

通过数值求解一个考虑吸湿效应的带有移动升华界面的多孔介质热、质传递耦合模型,理论考察介电材料对微波加热冷冻干燥过程的影响。介电材料用烧结的碳化硅（SiC）。甘露醇,一种典型的药物赋形剂被选为待干溶液中的溶质。模拟结果表明在微波冷冻干燥过程中使用介电材料可以加快冷冻干燥速率,特别是在待干溶液的固含量很低或者固体产品的介电损耗因子很小的情况下尤为有效。模型预测和实验测定的干燥曲线相比较显示了良好的一致性。通过考察冰饱和度和温度的分布侧形,研究分析了物料内部的质热传递机理,并讨论了干燥速率的控制因素。

英文摘要：

The effects of the dielectric material on the microwave freeze-drying process were theoretically studied by mathematically solving the heat and mass transfer model considering the hygroscopic effect with a moving boundary in the porous media. Sintered silicon carbide （SIC） was used as the dielectric material, and the mannitol, a typical pharmaceutical excipient, was selected as the solute in aqueous solution. Simulation results show that the dielectric material can significantly enhance the microwave freeze drying rate under the experimental operating conditions, especially when the solid content in the freeze dried solution is very low or the solid product has a very small dielectric loss factor. Comparisons of the drying curves display good agreements between experimental measurements and model predictions. Based on the profiles of ice saturation and temperature, mechanisms of heat and mass transfer inside the material were analyzed, and the drying rate-controlling factor was discussed.