多孔介质中高温气体非稳态渗流传热数值计算

Gas Flow and Heat Transfer in a Moving Packed Bed of Particle

针对水平导管中填充颗粒物料层内的高温气体渗流传热现象 ,考虑渗流与传热的相互作用并采用局部非平衡假设建立多孔介质中的瞬态渗流传热物理数学模型。研究不同情况下填充物料中的渗流速度和气固温度分布。计算结果表明 ,高温热气体对水平导管中移动颗粒料层的热渗透主要发生在渗流入口端区域 ,随着渗流时间延长 ,热渗透深度沿导管推进。增大入口渗流速度以及减小出料速度 ,将导致物料温度沿导管慢速下降 ,热渗透深度扩大 ,热渗透作用区域内的物料温度水平提高。在热渗透作用区域 ,孔隙率对流场和温度场有很大的影响。研究结果对于高温反应器的颗粒输运和给料器的设计与运行有一定的参考作用。

High heat penetration into a moving packed bed of particle is described mathematically with a comprehensive gas flow and heat transfer model.Considering the complicated mix of fluid flow and heat transfer and by using the thermal non uniform conditions,the transient distribution of gas velocity,the temperature field of gas and solid in the packed bed are examined for different conditions.The results show that the thermal infection to the moving packed bed particles by the seepage flow fluid is high only in the position near the gas entrance.The thermal penetration depth moves with the interrupting time along the pipe and tends to increase with the seepage flow velocity.In the thermal penetration influence field,the porosity of solid bed has important effects on the gas field and temperature field.