茄子冷冻干燥冻结过程模型的建立与求解

Modeling and numerical solution of eggplant freezing during freeze-drying process

该文以茄子球形样本为对象,研究果蔬物料冷冻干燥中预冻模型的建立及求解方法。通过能量衡算建立了果蔬冻结过程的非稳态数学模型,依据冻结过程试验参数,给出了冻结过程中物料液相区和固相区温度变化所满足的定解问题。采用"欧拉向后差分格式"数值计算方法,对冻结模型进行了数值求解,得出了茄子在冻结过程中冻结界面的移动规律和冻结时间。试验结果表明,所建模型能够准确地描述茄子的冻结过程,采用的数值解法是可行的。该文研究方法及结果为果蔬物料冷冻干燥预冻结过程模型的建立与求解提供了参考,并为果蔬冷冻干燥预冻结过程的优化控制提供了科学依据。

Taking the research object of eggplant spherical samples,the modeling and numerical solution to the pre-freezing process of fruits and vegetables were studied.The non-steady-state mathematical model of fruits and vegetables was established by means of energy balance.Based on the test process parameters,the problem for determining solution was given,which met the temperature changing of samples in liquid phase region and solid phase region during the freeze-drying process.Using numerical method of Euler receding difference scheme,the numerical solution to the freezing mathematical model was found,and the freezing time and the displacement law of freezing boundary were concluded.Test results showed that：the model could describe the freezing process of eggplant accurately,and the numerical solution was feasible.The research provided a means of modeling and solution to fruits and vegetables,and the theoretical basis for optimal control was proposed during the pre-freezing process.