摘要
该文基于谷物等温吸附原理和局部热湿平衡假设,建立和验证了吸湿性多孔介质内部自然对流和热湿耦合传递的数学模型,并采用数值模拟的方法考察了由于圆筒仓外季节性的大气温度变化而导致的仓储粮堆内部自然对流流动对粮堆内部热量传递和水分迁移的影响。通过数值模拟预测和分析了冬季和夏季两种情况下,高度为16 m、直径为10 m的圆筒仓内部自然对流流场、温度和水分分布规律。
Temperature gradients developed due to the seasonal variations in ambient temperatures cause natural convection airflow, heat transfer and migration of moisture within the bulk grain. In present paper, a mathematical model of natural convection heat and moisture transfer is developed by reflecting the change in air moisture on the grain moisture through the sorption isotherm. Natural convection flows are computed by solving a Brinkman-Darcy equation. The effect of temperature gradients on natural convection, heat transfer and moisture migration is simulated numerically by using Multiphisycs COMSOL 4.3. The validity of the numerical model is ascertained by comparing the predicted results with experimental and numerical results in the literatures. The model is applied to predict the airflow patterns, temperature and grain moisture distributions under conditions approximating winter and summer storage periods in silo with 10 m in diameter a height of 16 m. The predictions of moisture and temperature distribution are consistent with field observations.
出处
《水动力学研究与进展（A辑）》
CSCD
北大核心
2014年第4期487-496,共10页
Chinese Journal of Hydrodynamics
基金
国家自然基金(51276102)
山东省自然基金(ZR2011EEM011)
国家粮食公益专项(201313001)~~
关键词
谷物储藏
自然对流
热量传递
水分迁移
数值模拟
grain storage, natural convection, heat transfer, moisture migration, numerical simulation
