变温加热条件下谷物颗粒内的温湿传递机理研究

项目名称： 变温加热条件下谷物颗粒内的温湿传递机理研究

项目编号： No.51476009

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 能源与动力工程

项目作者： 王立

作者单位： 北京科技大学

项目金额： 82万元

中文摘要： 我国谷物机械化干燥普及率低，因未及时干燥造成的粮食损失数量惊人。谷物干燥技术与装备是我国农业机械化进程中的最短板。目前国内外谷物干燥均采用薄层干燥的方式。只有厚层干燥才能满足我国对谷物干燥设备小型化和可移动化的特殊国情要求。厚层干燥的关键是干燥均匀化的问题。在多年研究工作的基础上，我们提出了变温交变气流和振动相结合的厚层干燥新方法。研究内容包括：对谷物颗粒水分核磁共振T2谱和拉曼谱特征峰进行指征与标定,将核磁共振和拉曼谱方法应用于谷物颗粒中的水分扩散机理研究；实验研究干燥过程中谷物颗粒的物理结构、水分分布及结合形式对水分扩散行为的影响；这些影响在扩散系数中的关系表达；振动与变温交变气流耦合干燥过程中谷物的温湿扩散特征；耦合变温交变气流和颗粒对流因素的干燥动力学数学模型的建立与数值模拟研究。项目研究将为发展紧凑（小型化）、高效节能的谷物干燥技术和设备研发奠定理论基础，提供技术支撑。

中文关键词： 温湿扩散；扩散系数；核磁共振；拉曼光谱；振动床

英文摘要： Due to the low application of mechanized drying technology, grain loss caused by not timely drying is a surprisingly enormous. Grain drying technology and equipment is the short slab in China's process of agricultural mechanization. The grain drying processes generally use thin-layer drying methods at home and abroad. The thick layer drying technology is the only way to meet our country's special requirement for miniaturization and mobility of grain drying equipment. Moisture uniformity is the key issue for thick layer grain drying. Based on many years research, we propose a new method for thick layer grain drying: variable temperature and alternating airflow coupled with vibration (VTAACV). The study includes: indication and calibration of the spectral feature peaks of nuclear magnetic resonance T2 and Raman spectroscopy and the utilization of NMR and Raman spectroscopy in grain moisture measurement; experimental studying the effects of physical structure changing, water distribution and binding water types on moisture diffusion behavior in grain particles in drying process; expressing of the relationship between these effects and the diffusion coefficient; humidity diffusion characteristics in grain particle layer under variable temperature and alternating airflow heating coupled with vibration; Mathematical model of grain drying under VTAACV; and experiment and numerical simulation investigation.

英文关键词： temperature and moisture diffusion;diffusion efficient;nuclear magnetic resonance;Raman spectroscopy;vibrating bed