稻谷热风干燥水分扩散特性及含水率预测

Water Diffusion Characteristics and Prediction of Moisture Content in Hot Air Drying of Rice

为深入研究稻谷热风干燥过程中的水分扩散特性,在稻谷热风干燥试验基础上,分析了不同温度下、不同含水率稻谷的水分扩散特性;利用灰色系统理论建立数学模型,针对45℃热风干燥的稻谷含水率进行预测并与试验数据进行比较。研究结果表明:不同初始含水率稻谷的水分扩散系数和活化能均随着干燥温度的升高而增大;相同干燥温度下,不同含水率稻谷的水分扩散系数不同,初始含水率越高,水分扩散系数越大,45℃干燥时,含水率为14.091%、23.368%、24.963%、25.253%稻谷的水分扩散系数分别为3.71×10^(-8)、3.73×10^(-7)、4.02×10^(-7)、5.78×10^(-7)。利用灰色模型预测稻谷干燥过程中含水率,预测结果显示:均方差比值和小误差概率精确等级均为一级,表明灰色预测模型适用于稻谷干燥过程中含水率预测。研究结果为稻谷高效均化干燥提供了理论与基础数据参考。

In order to further study the water diffusion characteristics of rice during hot air drying,based on the hot air drying experiment of rice,the water diffusion characteristics of rice with different moisture content during hot air drying at different temperatures were analyzed.The moisture content of rice was predicted at 45℃hot-air dryingand compared with the experimental data.The results showed that the water diffusion coefficient and activation energy of rice with different initial water content increased with the increase of drying temperature.Under the same drying temperature,the water diffusion coefficient of rice with different moisture content was different,and the higher the initial water content was,the greater the water diffusion coefficient was.When dried at 45℃,the water diffusion coefficients of rice with 14.091%,23.368%,24.963%and 25.253%moisture content were 3.71×10^(-8),3.73×10^(-7),4.02×10^(-7) and 5.78×10^(-7),respectively.The grey model was used to predict the moisture content in rice drying process,and the prediction results showed that the mean square error ratio and small error probability were both at the first level,which indicated that the grey prediction model was suitable for predicting the moisture content in rice drying process,and the research results provided theoretical and basic data reference for efficient homogenized drying of rice.