任广跃,张伟,张乐道,段续.多孔介质常压冷冻干燥质热耦合传递数值模拟[J].农业机械学报,2016,47(3):214-220.
Ren Guangyue,Zhang Wei,Zhang Ledao,Duan Xu.Numerical Simulation of Mass and Heat Transfer of Porous Media during Atmospheric Freeze Drying[J].Transactions of the Chinese Society for Agricultural Machinery,2016,47(3):214-220.
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多孔介质常压冷冻干燥质热耦合传递数值模拟   [下载全文]
Numerical Simulation of Mass and Heat Transfer of Porous Media during Atmospheric Freeze Drying   [Download Pdf][in English]
投稿时间:2015-09-07  
DOI:10.6041/j.issn.1000-1298.2016.03.030
中文关键词:  多孔介质  苹果片  常压冷冻干燥  质热耦合
基金项目:国家自然科学基金项目(31271972)
作者单位
任广跃 河南科技大学 
张伟 河南科技大学 
张乐道 河南科技大学 
段续 河南科技大学 
中文摘要:以苹果片为研究对象,研究了基于涡流管制冷效应的常压冷冻干燥技术处理含湿冷冻多孔物料的干燥机制。利用ANSYS ICEM CFD软件对常压冷冻干燥工况建立二维几何模型并对其进行网格划分,采用多孔介质模型,通过有限体积法对控制方程进行离散,迭代求解不同风速和温度下冷冻物料内部水分比及中心温度随时间的变化。通过分析不同干燥工况下物料质热传递变化得出最佳组合参数,研究该干燥条件下不同干燥时刻的速度场、温度场、压力场以及多孔介质干区迁移界面变化规律,并采用入口风速2.5m/s、辐射温度283.15K,对模型进行验证。借助SPSS-21软件对物料内部含水率与中心温度的试验值和模拟值进行相关性分析,其R2分别为0.564和0.982,表明试验值与模拟值有较好的一致性,所建模型适用于多孔介质的冷冻干燥。
Ren Guangyue  Zhang Wei  Zhang Ledao  Duan Xu
Henan University of Science and Technology,Henan University of Science and Technology,Henan University of Science and Technology and Henan University of Science and Technology
Key Words:porous media  atmospheric freeze drying  mass and heat transfer
Abstract:This research aims to explore the drying behaviors of the saturated frozen porous media during atmospheric freeze drying, which is based on the refrigeration of vortex tube. The experimental study to analyze heat and mass transfer in drying of apples was undertaken numerically. In the numerical part, a two dimensional geometric model of atmospheric freeze drying conditions was constructed by using the software of ANSYS ICEM CFD, and the model was divided into meshes for the computational domain which can make the numerical simulation results clearer. The changes of moisture ratio and core temperature of frozen material was obtained through iterative solution, which was adopted the methods of porous jump model and the finite volume method(FVM), under different conditions of inlet velocity and radiation temperature. The optimal combination of the parameters was got by means of analyzing the changes of mass and heat transfer of drying sample during different conditions. According to the simulation results of optimal parameters, heat and mass transfer for material can be investigated from velocity field, temperature field, pressure field and the migration of drying area in porous media under different time. In the experimental part, apple slices was applied to drying process. As expected, while drying condition was carried out at a wind speed of 2.5m/s on the inlet and an irrational temperature of 283.15K, experimental values are fitted with the simulated values. The correlation analysis was carried out between experimental and simulated value of material moisture ratio and core temperature through the SPSS-21 analysis software, the R2 value was 0.564 and 0.982 respectively. Such a methodology could be reasonable for studying of freeze drying.

Transactions of the Chinese Society for Agriculture Machinery (CSAM), in charged of China Association for Science and Technology (CAST), sponsored by CSAM and Chinese Academy of Agricultural Mechanization Science(CAAMS), started publication in 1957. It is the earliest interdisciplinary journal in Chinese which combines agricultural and engineering. It always closely grasps the development direction of agriculture engineering disciplines and the published papers represent the highest academic level of agriculture engineering in China. Currently, nearly 8,000 papers have been already published. There are around 3,000 papers contributed to the journal each year, but only around 600 of them will be accepted. Transactions of CSAM focuses on a wide range of agricultural machinery, irrigation, electronics, robotics, agro-products engineering, biological energy, agricultural structures and environment and more. Subjects in Transactions of the CSAM have been embodied by many internationally well-known index systems, such as: EI Compendex, CA, CSA, etc.

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