摘要
以细胞作为传输过程的基本单元,建立了一维质量传递和热量传递数学模型。渗透脱水质量传递模型考虑了不同组分在细胞内、外,通过细胞膜与胞间连丝的质量扩散,以及在细胞外空间的集流传输。冻结过程的数学模型建立基于热平衡方程,且考虑了相变问题。通过Matlab软件有限差分方法求解方程,得到的实验结果(芒果渗透脱水过程的失水率和增固率,以及冻结过程的冻结曲线)与模拟结果十分接近,相对偏差控制在15%之内,从而验证了模型的有效性。结果表明:所建立的数学模型可详细描述芒果渗透脱水过程中细胞内、外水和蔗糖的质量浓度分布,以及冻结过程中的温度变化。
The one-dimensional mass transfer and heat transfer mathematical models were developed by taking mango cells as a basic unit for the effective prediction and process control of osmo-dehydrofreezing.The mass balance equations for the diffusion of different species were established separately for the intracellular and extracellular volumes taking into account the transfer through the cellular membrane and the plasmodesma. Moreover,the model also considered bulk flow of different species in the extracellular volumes. The thermal balance equations for modeling the subsequent freezing step were developed,which included the phase change phenomena. The numerical solutions were solved by a finite difference method with Matlab programs. A good agreement was obtained between the simulated and experimental results including water loss and solid gain during osmotic dehydration and temperature profile during freezing,and the relative error was controlled in 15%,which proved that this model was practical. Numerical results could describe the distribution of water and sucrose in the intracellular and extracellular volumes of mangoes during osmotic dehydration and show the change of temperature at different time during freezing.
出处
《农业机械学报》
EI
CAS
CSCD
北大核心
2014年第12期262-270,共9页
Transactions of the Chinese Society for Agricultural Machinery
基金
中国农业科学院创新工程资助项目
关键词
芒果
渗透脱水
冻结
质量传递
热量传递
模拟
Mango Osmotic dehydration Freezing Mass transfer Heat transfer Modeling
