Computational study of the effects of material properties on heat transfer in gas fluidization
Computational study of the effects of material properties on heat transfer in gas fluidization
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DOI：
10.1021/ie3015999
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发表时间：
2012-08
影响因子：
4.2
通讯作者：
Q. Hou;Zongyan Zhou;A. Yu
中科院分区：
文献类型：
--
作者：
Q. Hou;Zongyan Zhou;A. Yu
采用离散元法和计算流体力学相结合的方法，研究了不同粉体在气体流态化过程中的传热特性。首先，研究了A组粉末在三种流动状态下的传热特性。然后，Hamaker常数和颗粒尺寸的影响，都与货车德瓦尔斯力，进行了详细的研究。结果表明，在床层温度较高的情况下，对流换热占主导地位，而辐射换热占主导地位。然而，传导热传递也起作用，取决于流动状态和材料性质。在一定条件下，观察到Hamaker常数和颗粒尺寸的显着影响。最后，努力量化的Hamaker常数，颗粒尺寸和入口气体速度的影响。研究结果将有助于更好地理解和预测气体流化的传热。
Heat transfer characteristics of different powders in gas fluidization are investigated by means of a combined approach of discrete element method and computational fluid dynamics. First, the heat transfer characteristics in three flow regimes of group A powders are examined. Then, the effects of the Hamaker constant and particle size, both related to the van der Waals force, are investigated in detail. The results confirm that the convective heat transfer is dominant, and radiative heat transfer becomes important when the bed temperature is high. However, conductive heat transfer also plays a role depending on the flow regimes and material properties. Significant effects of the Hamaker constant and particle size are observed under certain conditions. Finally, an effort is made to quantify the effects of the Hamaker constant, particle size, and inlet gas velocity. The findings should be useful for better understanding and prediction of the heat transfer in gas fluidization.