| 基于数值模拟的红枣片不同干燥方式热质传递仿真与试验 |
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| 引用本文： | 李孟卿,张小强,朱丽春,张茜,贾文婷,金新文,杨旭海.基于数值模拟的红枣片不同干燥方式热质传递仿真与试验[J].农业工程学报,2024,40(6):50-59. |
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| 作者姓名： | 李孟卿 张小强 朱丽春 张茜 贾文婷 金新文 杨旭海 |
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| 作者单位： | 石河子大学机械电气工程学院，石河子 832003;石河子大学机械电气工程学院，石河子 832003;农业农村部西北农业装备重点试验室，石河子 832003;新疆农垦科学院农产品加工研究所，石河子 832000;石河子大学机械电气工程学院，石河子 832003;现代农业机械兵团重点试验室，石河子 832003 |
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| 基金项目： | 国家自然科学基金项目（32360605）；新疆生产建设兵团科技创新人才计划（2021CB042；2023CB016）；新疆农垦科学院科技创新团队（2022-2024）。 |
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| 摘 要： | 为揭示并对比红枣片热风干燥、红外热风干燥及红外真空脉动干燥中的传热传质及干燥动力学特性，并填补关于果蔬红外真空脉动干燥数值模型的研究空白。该研究使用菲克扩散定律、安托因方程及比尔朗伯定律等控制方程分别建立了针对三种干燥方式的红枣片三维热质传递耦合数值模型，并利用试验数据对模型的可靠性进行验证。该研究基于枣片的实际几何尺寸进行建模并利用COMSOL求解。结果表明：1）与热风干燥相比，红外热风与红外真空脉动干燥分别缩短了46.43%和41.07%的干燥时间，且仿真结果与实测值吻合较好；2）温度场模拟图显示红外辐射可有效对红枣片内部进行加热，干燥20 min时红外热风和红外真空干燥的物料中心温度较热风干燥分别提高了11.33%和5.59%；3）模拟数据显示红外真空脉动干燥中的压力变化对干燥动力学产生了明显影响，其中含水率和干燥速率随压力脉动分别呈现阶梯状和峰状分布，并且干燥速率对压力变化的敏感性随着物料含水率的下降而下降；4）将测得的红枣片品质及质构特性与仿真数据进行综合对比，给出了关于分段组合干燥研究方向的见解，并对果蔬干燥数值模型的发展方向进行展望。该研究建立并验证了红枣片三种干燥方式下的数值模型，并结合模拟结果对各干燥过程的特点进行分析，对未来不同果蔬数值模型的建立及干燥机理的研究具有重要意义。
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| 关 键 词： | 干燥动力学 热质传递 数值模型 红外辐射 压力脉动 |
| 收稿时间： | 2023/9/5 0:00:00 |
| 修稿时间： | 2023/10/21 0:00:00 |
Numerical simulation and experiment on heat and mass transfer in different drying modes of red jujube slices |
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| LI Mengqing,ZHANG Xiaoqiang,ZHU Lichun,ZHANG Qian,JIA Wenting,JIN Xinwen,YANG Xuhai.Numerical simulation and experiment on heat and mass transfer in different drying modes of red jujube slices[J].Transactions of the Chinese Society of Agricultural Engineering,2024,40(6):50-59. |
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| Authors: | LI Mengqing ZHANG Xiaoqiang ZHU Lichun ZHANG Qian JIA Wenting JIN Xinwen YANG Xuhai |
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| Institution: | College of Mechanical and Electrical Engineering, Shihezi University, Shihezi 832003, China;College of Mechanical and Electrical Engineering, Shihezi University, Shihezi 832003, China;Key Laboratory of Northwest Agricultural Equipment, Ministry of Agriculture and Rural Affairs, Shihezi 832003, China;Xin jiang Academy of Agricultural and Reclamation Science, Shihezi , 832000, China; College of Mechanical and Electrical Engineering, Shihezi University, Shihezi 832003, China;Xinjiang Production and Construction Corps Key Laboratory of Modern Agricultural Machinery, Shihezi 832003, China |
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| Abstract: | This study aims to reveal and compare the heat and mass transfer and the drying kinetic parameters of red jujube slices during hot air drying, infrared combined hot air drying, and infrared vacuum pulsation drying. A three-dimensional coupled model was established for the heat and mass transfer of jujube slices under the three drying modes, according to the control equations of Fick''s law of diffusion, Antonin''s equation and Beer Lambert''s law. The reliability of the model was verified using experimental data. Subsequently, the utility of the model was tested by varying parameters, such as hot air temperatures, infrared radiation intensities, and vacuum pulsation ratios. Each drying was further analyzed to combine with the measured quality indexes, textural properties and microstructure. The actual geometry of jujube slices was simulated and solved using COMSOL Multiphysics 6.0. The result shows that: 1) The infrared hot air and infrared vacuum drying saved 46.43% and 41.07% of the drying time, compared with the hot air drying. The simulation was in better agreement with the measured values (the coefficients of determination R2 for dry basis moisture content and temperature were 0.964, 0.959, 0.917 and 0.947, 0.922, 0.951, respectively). 2) The temperature field diagram showed that the effective heat of the inside of the material, and the center temperature of the material during infrared hot air and infrared vacuum drying increased by 11.33% and 5.59%, respectively, compared with the hot air drying, when drying for 20 min. The high energy density and penetrability of infrared radiation significantly improved the drying efficiency. 3) The simulation data showed that there was a significant effect of pressure variation on the drying kinetics in the infrared vacuum pulsation drying. The increasing vacuum time was favorable to the decrease of moisture. The water content and drying rate showed a step and peak distribution with the pressure pulsation. The sensitivity of the drying rate to the pressure change decreased with the decrease in the water content of the material. Further explanation was provided for the formation of porous structure in the red jujube slices during vacuum pulsation drying. 4) A comparison was made on the measured quality and textural properties of jujube slices with the simulated data. Segmented drying was proposed for the future direction in the numerical model of heat and mass transfer for fruit and vegetable drying. For example, the nutritional content and microstructure of products were coupled with the numerical model in the future. The nutritional, structural and rheological properties of materials can be expected to be quantified and visualized during drying. The numerical models of jujube slices were established and verified under three drying modes. The characteristics of each drying were obtained after simulation. It is of great significance to establish numerical models for fruit drying. |
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| Keywords: | drying kinetics heat and mass transfer numerical modeling infrared radiation pressure pulsation |
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