循环式谷物干燥机干燥过程的模拟计算和分析

Simulation and analysis of drying process for recirculating grain dryer

论述了利用薄层干燥方程理论建立的可模拟循环式谷物干燥机的干燥模型。用此模型可以计算出干燥水稻所需的干燥时间、能耗、缓苏程度系数,以及干燥过程中谷物水分变化和排气温、湿度的变化。经实际验证,所建模型模拟计算结果与试验结果基本相符,可用于分析此类干燥机的工作情况,为研发和改进此类干燥设备提供了有效技术手段。通过模型计算,选择适当的风温和风量,可较好地兼顾干燥时间和能量消耗的需求;模型计算表明干燥初期使用较低的风温,以后逐步升温的变温干燥可节约能量,提高稻谷品质;适当增大干燥段的容量可较大幅度降低干燥时间和能耗。

The theory of thin-layer drying equations was used to set up a drying model which could simulate recirculating grain dryer.The model could be used to calculate the data of drying time,energy consumption,tempering coefficient,as well as the changes of grain moisture,temperature and humidity of exhaust air in drying process.By experimental validation,the model simulation conformed to the experimental results,and the model could be used to analyze the same kind of dryer＇s working condition,and provide effective technical means for research and development as well as the improvement of the dryers.According to the model calculation,selecting appropriate temperature and mass flow rate of air can balance drying time and energy consumption,and the operation that could save energy and improve the grain quality was to keep low drying temperature at the initial stage of drying and gradually increase it.Proper increase in drying section cubage will significantly reduce drying time and energy consumption.