基于粮堆尺度的稻谷干燥过程中流体流动及热湿耦合传递的研究  

Fluid Flow and Heat⁃moisture Coupling Transfer in Rice Drying Process Based on Grain Stack Scale

作　　者：刘博 段海峰 杨开敏[1] 杜鑫明 刘俊杰 王远成[1] Liu Bo;Duan Haifeng;Yang Kaimin;Du Xinming;Liu Junjie;Wang Yuancheng(College of Thermal Engineering,Shandong Jianzhu University,250101;Shandong Inspur Intelligent Building Technology Co.,Ltd,250101)

机构地区：[1]山东建筑大学热能工程学院,250101 [2]山东浪潮智慧建筑科技有限公司,250101

出　　处：《粮食储藏》2024年第5期8-15,共8页Grain Storage

基　　金：国家重点研发计划(2024YFE0106800);山东省自然科学基金(ZR2021ME199);山东省高等学校“青创人才引育计划”。

摘　　要：谷物的质量受干燥条件的影响很大,应尽量减少干燥过程中的干物质损失。本研究采用离散元法和计算流体力学方法,构建了由稻谷颗粒组成的粮堆。基于流固耦合的传热传质原理,建立了热湿传递模型,并通过对稻谷的干燥温度和初始含水率的控制,探讨了干燥过程中谷堆内温度和含水率的变化规律。数值模拟工作提供了对干燥过程中粮堆内部流体流动和热湿耦合传递的深入理解,并讨论了温度和湿度对干燥的影响。研究结果表明,粮堆的非均匀孔隙结构以及稻谷表面的间隙导致了复杂的气流模式,导致“通风死角”的形成。在整个干燥过程中,观察到不同粮层之间的温度和湿度差异。由于水分扩散系数的作用,稻谷内部和表面的含水量存在差异。粮堆中的热量和水分通过加热空气的流动和稻谷的热湿扩散从底层传递到上层。同时,研究发现干燥曲线的曲率随着干燥条件的变化而变化,尤其是在温度达到60℃时变化最为显著。该研究可为粮食的安全储存提供参考和理论依据。Grain quality is greatly affected by drying conditions and dry mass loss during drying should be mini⁃mized.In this study,the discrete element method and computational fluid dynamics method were used to construct a grain pile composed of rice grain.Based on the principle of fluid-solid coupling heat and mass transfer,a heat and moisture transfer model was established.By controlling the drying temperature and initial moisture content of rice,the variation law of temperature and moisture content in rice pile during drying was discussed.The numerical solutions provide an insight into the fluid flow and coupled heat and humidity transfer inside the grain pile during drying,and the effects of temperature and humidity on drying are discussed.The results show that the non⁃uniform pore structure of grain pile and the gap on rice surface lead to complex airflow patterns,resulting in the formation of“ventilation dead zone”.Temperature and humidity differences between different grain layers were observed throughout the drying process.Due to the effect of water diffusion coefficient,there are differences in water content inside and on the surface of rice.The heat and moisture in the grain pile are transferred from the bottom layer to the upper layer by the flow of heated air and the heat and moisture diffusion of the rice.At the same time,it is found that the curvature of the drying curve changes with the change of drying conditions,especially when the temperature reaches 60℃.This study can provide reference and theoretical basis for safe storage of grain.

关 键 词：稻谷 非球形颗粒 数值模拟 热湿耦合传递 孔隙结构 

分 类 号：S375[农业科学—农产品加工]