基于COMSOL的平房仓冷却通风过程中粮堆热湿耦合传递研究

粮仓冷却干燥通风是确保储粮安全的重要技术措施,在此过程中粮堆内部的热湿耦合迁移过程非常复杂。在COMSOL软件中,建立了冷却干燥通风过程中高大平房仓的三维物理模型,通过修改COMSOL内置材料方程、耦合渗流、能量守恒、动量守恒和水分迁移控制方程,以实测的送风空气温度和湿度为入口边界条件,数值模拟了湍流、湿空气传热、湿空气传质、多孔介质传热、多孔介质传质等多个物理场,并考虑了热湿耦合、温度耦合和流动耦合,对高大平房仓粮堆内冷却干燥通风过程中的热湿迁移规律进行了研究。基于实际高大平房仓的验证结果表明,通过修改COMSOL内置方程可以准确模拟预测冷却干燥通风过程中粮堆内热湿耦合传递过程,数值模拟结果可用于指导粮仓冷却干燥通风过程和粮仓通风系统优化。

Numerical simulation of coupled heat and moisture transfer in stored grains during cooling ventilation by using COMSOL

Cooling and drying ventilation of big warehouses is an important technique to ensure the stored grain safety. Coupled heat and moisture transfer in stored grains during cooling and drying ventilation is a very complex multi-field coupling process. A three-dimensional physical model of a real large warehouse was established in the COMSOL software. The implementation techniques include modification of the built-in material equations of COMSOL and control equations of coupling analysis of pore fluid flow, conservation of energy, conservation of momentum, and water transfer. Measured temperature and moisture of wet air?is used as the inlet boundary conditions. Physical fields of turbulence flow, heat transfer of wet air, wet air mass transfer, heat transfer in porous media, and mass transfer in porous media are involved in the COMSOL numerical simulation. Coupled physical fields of heat and humidity coupling, temperature coupling and flow coupling are also considered in the COMSOL numerical simulation. Results of verifications based on a large warehouse shows that coupled heat and moisture transfer in stored grains during the cooling and drying ventilation can be accurately?predicted by modifying the built-in equations of COMSOL software. The results of numerical simulation can be used to guide the cooling and drying ventilation process and optimization of ventilation system of big warehouses.