摘要：
为了获得最适用于烟草干燥的动力学模型,达到设计、优化和控制烟草干燥过程的目的,采用湿度发生器联用热重技术(TGA)研究了65°C&RH 15%、75°C&RH 10%和85°C&RH 5%条件下片烟的干燥动力学行为,并利用REA(Reaction engineering approach)以及8种经验或半经验的薄层干燥模型分别对不同温湿度条件下的片烟干燥行为进行模拟.结果表明:①干燥温度越高,相对湿度越小时,片烟的干燥速率越快,平衡含水率越低;②REA模型预测的片烟干燥动力学曲线与实验曲线能够很好地吻合,尤其是在含水率由20%降至12%阶段;8种薄层干燥模型中Two term模型拟合出的R2值最大,均方根误差(RMSE)最小,是描述片烟干燥行为较合适的模型;③薄层干燥模型仅仅是获得特定温湿度条件下相对应的动力学参数,而REA模型是将温度和湿度作为变量引入模型中,模型中的动力学参数可以描述任意温湿度条件下的片烟干燥动力学行为;④REA模型构造简单,预测准确快速,较Two term模型更具有普适性、实用性.%In order to select a kinetic model best fit for the design, optimization and control of tobacco drying process, the drying kinetic behavior of tobacco strips under the conditions of 65 °C & RH 15%, 75 °C & RH 10%, 85 °C & RH 5% was investigated with a humidifier combined with TGA (Thermogravimetric analyzer). The drying behavior of tobacco strips was simulated by REA (Reaction engineering approach) model and eight selected thin layer drying models (semi-empirical or empirical). The results showed that: 1) With the rise of temperature and decrease of humidity, the drying rate of strips raised and the equilibrium moisture content of strips lowered. 2) The drying kinetic curves predicted by REA model well agreed with experimental curves, especially at the stage when the moisture content decreased from 20% to 12%. Among eight thin layer drying models, Two term model was the best for predicting the drying behavior of strips with the highest R2 (determination coefficient) and the lowest RMSE (root mean square error). 3) Thin layer drying model reflected only the kinetic parameters corresponding to specified drying conditions, while in the REA model the temperature and humidity served as variables, it enabled the kinetic parameters in REA model to describe the drying kinetic behavior at any drying condition. 4) REA model was simple in structure, fast and accurate in prediction, more universal and practical than Two term model.
