浅圆仓不同运行方式对粮堆通风调温效果影响

The effect of different operation modes of squat silo on the ventilation and temperature regulation of grain stacks

浅圆仓在粮食储藏中有着广阔的应用前景,探究垂直通风与径向通风系统不同运行方式的通风降温效果,有助于为粮食的安全储存提供支持。文章以浅圆仓内粮堆(大豆)为研究对象,通过有限体积法,数值模拟了3种不同风道在正压上行通风和负压下行通风为期14 d的调温过程,获得了粮堆内部的气流和温度分布情况,并对比分析了通风降温速率、均匀性与能耗等。结果表明:各通风方式下均无通风死角,形式差异导致流向与涡团的位置差异;垂直风道正、负压方式下通风7 d后仓内无高温区域,其他两种风道出现高温区域,14 d时各种工况均无高温区域;只有径向风道的负压通风的降温速率与最终温度低于正压通风;径向风道的通风均匀性优于其他两种风道,正压通风的均匀性优于负压通风的;而正压通风的能耗普遍低于负压通风。

The squat silo has an extensive prospect in grain storage.The paper of ventilation and temperature regulation effect of conventional vertical ventilation system and new radial ventilation system can provide support for the actual grain storage process.In this paper,the grain type is soybean.The 14-day temperature regulation process of three different air ducts in squat silo under forward ventilation and reverse ventilation is numerically simulated by the finite volume method.The air flow and temperature distribution in the grain pile are obtained,and the ventilation cooling rate,uniformity and energy consumption are compared and analyzed.The results indicate that there is no ventilation dead corner in all ventilation modes,and the difference of ventilation modes leads to the difference of flow direction and vortex position.Under the positive and negative pressure form of vertical air ducts,there is no high temperature area in the squat silo for 7 days of ventilation,while the other two air ducts exhibit high-temperature areas.And there is no high temperature area in all working conditions for 14 days.Only when the air duct is radial,the cooling rate and final temperature of negative pressure ventilation are lower than those of positive pressure ventilation.The ventilation uniformity of radial air duct is better than the other two air ducts,and the uniformity of positive pressure ventilation is better than negative pressure ventilation.The energy consumption of positive pressure ventilation is generally lower than that of negative pressure ventilation.