为了优化花椒干燥室内部流场均匀性,提高干燥品质,该文以空气源热泵干燥箱干燥花椒实验为基础,依据局部非热平衡理论,建立花椒多孔介质传热传质数值模型,通过实验对比验证模型准确性,并综合评价指标温度不均匀系数、速度不均匀系数与水分不均匀系数,对不同数量的送风口Case 1~Case 5(1、2、4、8、16)的结构进行温度场、速度场、含水率分布特性分析,确定干燥条件下最佳的风口数量。结果表明:当各层含水率降至安全含水率11%时,模拟得出水分降至11%所用时间为435 min,与实验结果较为吻合,误差在0.1%~11%;第15 min时模拟值与物料各测点温度误差为0.1%~3.77%,验证了模拟的可靠性;不同风口数量条件下,Case 3的温度不均匀系数最小,均匀性最好;Case 5虽速度不均匀系数最小,但流场风速仅约0.3 m/s;且Case 4和Case 5的含水率明显高于Case 3,在干燥2 h时,分别比Case 3高出39%和75%,综合考虑,当送风口数量为4个时,箱内的温度场和相对湿度场均匀性最佳,能量利用系数最高。
To optimize the internal flow uniformity of the Zanthoxylum bungeanum drying chamber and enhance drying quality, this study established a numerical model for heat and mass transfer in Z.bungeanum porous media based on local thermal equilibrium theory.The model was validated through experiments conducted using an air source heat pump drying oven.A comprehensive evaluation index, including temperature non-uniformity coefficient, velocity uniformity coefficient, and moisture non-uniformity coefficient, was used to analyze the temperature field, velocity field, and water content distribution characteristics across different numbers of air supply outlets (Case 1-Case 5:1, 2, 4, 8, 16).The optimal number of air outlets under dry conditions was determined.Results showed that when the moisture content of each layer decreased to 11%, it took 435 min, consistent with experimental results, with an error range of 0.1%-11%.The simulated material temperature at each measuring point at 15 min had an error of 0.1%-3.77% compared to actual measurements, verifying the reliability of the simulation.Under different tuyere numbers, Case 3 exhibited the lowest temperature inhomogeneity coefficient and best uniformity.In Case 5, although the velocity inhomogeneity coefficient was the smallest, the wind speed of the flow field was only about 0.3 m/s.Moreover, the moisture content of Case 4 and Case 5 was significantly higher than that of Case 3, being 39% and 75% higher after 2 h of drying, respectively.Considering all factors, when the number of air supply outlets is 4, the temperature field and relative humidity field inside the box achieve the best uniformity and highest energy utilization efficiency.
[1] 王纪辉, 陈应福, 侯娜, 等.源自不同产地青花椒主要特征品质分析[J].食品工业, 2018, 39(8):322-325.
WANG J H, CHEN Y F, HOU N, et al.Analysis of main characteristics of Zanthoxylum schinifolium Sieb.et Zucc from different areas[J].The Food Industry, 2018, 39(8):322-325.
[2] 吴青荣, 王高敏, 曾恩, 等.农产品热泵组合干燥研究进展[J].食品科技, 2016, 41(11):88-92.
WU Q R, WANG G M, ZENG E, et al.Advances on heat pump combined drying of agricultural products[J].Food Science and Technology, 2016, 41(11):88-92.
[3] 金听祥, 马家豪.木瓜热泵干燥特性数值模拟及试验研究[J].食品与发酵工业, 2025, 51(1):266-272.
JIN T X, MA J H.Numerical simulation and experimental study of heat pump drying characteristics of papaya[J].Food and Fermentation Industries, 2025, 51(1):266-272.
[4] 董霖, 王爽, 欧阳锐凌, 等.网带式花椒干燥机流场模拟与结构优化[J].农业机械学报, 2023, 54(S1):373-380.
DONG L, WANG S, OUYANG R L, et al.Flow field simulation and structural optimization of mesh-belt pepper drying machine[J].Transactions of the Chinese Society for Agricultural Machinery, 2023, 54(S1):373-380.
[5] 朱伊枫, 孙丽萍, 李季成.干燥窑结构改进对风速流场均匀性的影响[J].农业工程学报, 2021, 37(24):327-337.
ZHU Y F, SUN L P, LI J C.Influence of improved structure of drying kiln on the uniformity of wind velocity flow field[J].Transactions of the Chinese Society of Agricultural Engineering, 2021, 37(24):327-337.
[6] 满余, 童军杰.基于红薯片多孔介质的间歇微波干燥数值分析[J].食品与发酵工业, 2024, 50(4):157-164.
MAN Y, TONG J J.Numerical analysis of intermittent microwave convective drying based on porous media for sweet potato slices[J].Food and Fermentation Industries, 2024, 50(4):157-164.
[7] 康宏彬, 邓先奋, 肖波, 等.热泵干燥室的流场模拟及结构优化[J].农机化研究, 2024, 46(10):15-20.
KANG H B, DENG X F, XIAO B, et al.Flow field simulation and structural optimization of Chen pi heat pump drying chamber[J].Journal of Agricultural Mechanization Research, 2024, 46(10):15-20.
[8] ZHAN B F, WANG Z C, SHAO S Q, et al.Simulation investigation on a novel open-loop air cycle heat pump drying system[J].International Journal of Refrigeration, 2022, 141:31-42.
[9] 霍二光.菊花烘干室内气流组织模拟与优化研究[D].南昌:南昌大学, 2016.
HUO E G.Research on simulation and optimization of airflow structure in chrysanthemum drying room[D].Nanchang:Nanchang University, 2016.
[10] 于海明, 李海源, 汪春, 等.秧盘干燥机气流分配室流场均匀性仿真分析[J].农机化研究, 2020, 42(2):15-21.
YU H M, LI H Y, WANG C, et al.Simulation analysis of flow field uniformity in air distribution room of rice seedbed microwave hot air coupling dryer[J].Journal of Agricultural Mechanization Research, 2020, 42(2):15-21.
[11] AMJAD W, MUNIR A, ESPER A, et al.Spatial homogeneity of drying in a batch type food dryer with diagonal air flow design[J].Journal of Food Engineering, 2015, 144:148-155.
[12] 王鹏浩.海带干燥特性及热泵烘干室气流组织研究[D].哈尔滨:哈尔滨理工大学,2019.
WANG P H.Study on drying characteristics of kelp and airflow structure of heat pump drying chamber[D].Harbin:Harbin University of Science and Technology, 2019.
[13] 吴业豪.花椒多孔堆积填充床对流干燥传热传质特性[D].西安:西安科技大学,2021.
Wu Y H.Heat and mass transfer characteristics of convective drying in porous packed bed of Zanthoxylum bungeanum[D].Xi'an:Xi'an University of Science and Technology, 2021.
[14] 王福军.计算流体动力学分析-CFD 软件原理与应用[M].北京:清华大学出版社, 2004.
WANG F J.Computational Fluid Dynamics Analysis-CFD Software Principles and Applications[M].Beijing:Tsinghua University Press, 2004.
[15] WANG P, LIU G H, AO S M, et al.Numerical investigation of airflow and heat transfer characteristics and optimal design of the American ginseng drying room[J].Applied Thermal Engineering, 2021, 183:115885.
[16] 黄成就. 被子植物门: 双子叶植物纲: 芸香科[M]. 北京, 科学出版社, 1997.
HUANG C J. Angiosperm phylum: Dicotyledons: Rutaceae[M]. Beijing: Science Press, 1997.
[17] ZARE D, MINAEI S, MOHAMAD ZADEH M, et al.Computer simulation of rough rice drying in a batch dryer[J].Energy Conversion and Management, 2006, 47(18-19):3241-3254.
[18] 汪火良.多孔介质传热传质过程的数值模拟—烟叶烘烤过程模拟技术研究[D].昆明:昆明理工大学,2010.
WANG H L.Numerical simulation of heat and mass transfer process in porous media—research on simulation technology of tobacco baking process[D].Kunming:Kunming University of Science and Technology, 2010.
[19] 霍平, 王亚州, 李宁宁.基于CFD的干燥室流场均匀性优化研究[J].中国陶瓷, 2023, 59(6):74-82.
HUO P, WANG Y Z, LI N N.Optimization of flow field uniformity in drying chamber based on CFD[J].China Ceramics, 2023, 59(6):74-82.
[20] 张航, 邓胜祥.基于Shannon-Wiener指数的干燥过程中物料含水率均匀性计算及验证[J].农业工程学报, 2016, 32(20):290-297.
ZHANG H, DENG S X.Calculation and validation of moisture uniformity in drying process based on Shannon-Wiener index[J].Transactions of the Chinese Society of Agricultural Engineering, 2016, 32(20):290-297.
[21] 王安娜, 王赟, 彭小伟, 等.不同干燥方式对竹叶花椒叶品质的影响[J].中国农业科学, 2023, 56(18):3655-3669.
WANG A N, WANG Y, PENG X W, et al.Effects of different drying methods on the quality characteristics of dried Zanthoxylum armatum leaves[J].Scientia Agricultura Sinica, 2023, 56(18):3655-3669.
[22] 饶胜其, 徐富慧, 伏晴晴, 等.干制方式对九叶青花椒干燥特性和品质的影响[J].食品科学技术学报, 2025, 43(1):156-170.
RAO S Q, XU F H, FU Q Q, et al.Effect of drying methods on drying characteristics and quality of Zanthoxylum schinifolium Sieb.et Zucc.[J].Journal of Food Science and Technology, 2025, 43(1):156-170.
[23] 李江波, 薛韩玲, 陈 柳.热泵－太阳能花椒干燥系统的设计与数值模拟[J].江苏农业科学, 2019, 47(14):251-255.
LI J B, XUE H L, CHEN L.Design and numerical simulation of heat pump-solar Zanthoxylum drying system[J].Jiangsu Agricultural Sciences, 2019, 47(14):251-255.
