基于数值预测的稻谷横向降温保水通风最佳湿度研究

本实验基于多孔介质热湿传递原理和粮粒吸湿/解吸湿理论,建立了通风过程中粮堆内部热湿耦合传递方程,采用数值预测的方法,研究了吨粮通风量不变、粮堆初始温度与通风空气温度差8℃情况下,粮堆初始平衡湿度与通风空气湿度差分别为-5%、0%和5%时,粮堆内部温度和水分随时间的变化规律。探究了通风湿度对稻谷横向保水降温通风过程中粮堆温度和水分的影响,分析了一定初始粮温和水分时通风空气温湿度对降温保水的效果,得到了稻谷横向降温保水通风的最佳湿度。研究结果可以丰富和完善横向降温保水通风工艺,同时也为横向降温保水通风的操作提供依据。

Optimum Humidity of numerical prediction to cooling effect and water retention of large warehouse during cross ventilation

Based on the heat and mass transfer principle of porous media and the moisture absorption/desorption theory of grain, the coupled heat and moisture transfer equation in grain stack during ventilation was established. The numerical prediction method was used to study on the change of temperature and moisture content in bulk stored grain in warehouse during cross ventilation when the ventilation volume per ton of grain was constant, the initial temperature difference between grain stack and ventilated air temperature was 8 C, and the difference between initial equilibrium humidity and ventilated air humidity was -5%, 0% and 5%, respectively. The influence of ventilation air temperature and humidity on the effect of cooling and water retention was analyzed when the initial grain temperature and moisture were given. It was obtained that optimum humidity parameters of cooling and water retention during transverse ventilation. The research results can enrich and improve the cross ventilation technology, and also provide a basis for the operation of cross ventilation.