【摘要】 通过质量和能量衡算，建立了描述冷冻干燥过程的非稳态耦合热质传递动力学模型．计算模型可以从物理过程中区分升华干燥和解析干燥２ 个阶段，模型所需的输入参数较少，具有较大的灵活性．采用变时间步长和步进的算法求解数学模型，计算结果表明：干燥室压力的降低使升华干燥时间略有增加，却减少了解析干燥时间，有利于减少总干燥时间；尽管强化冻结层的传热可使升华干燥时间显著地减少，却增加了解析干燥时间，但总干燥时间并未由此明显减少．因而，增加冻结层的热通量对于总干燥时间的影响较小更多还原

【Abstract】 A dynamic model is developed to describe freeze drying by mass and energy balance. Primary and secondary drying are distinguished. Variable time step and marching algorithm are used in the numerical analysis. Results of computation show that a reduction in chamber pressure can decrease secondary and total drying time even though the primary drying time is increased. The latter is reduced by the enhancement of heat flux through the frozen layer while the secondary drying time is increased.更多还原