Research on Flow Analysis of Dense Gas-Solid Two-Phase Flows with Heat Transfer

本研究的目的是发展用于分析具有传热的致密气固两相流现象的数值格式。采用红外热像仪测量颗粒温度分布。实验结果与数值结果进行了比较。我们的实验和数值结果总结如下。实验用红外热像仪测量了二维流化床内颗粒温度的分布。一个可以传输红外线的尖晶石窗户被放置在前墙的中心。采用玻璃和铝两种不同的颗粒材料，研究了颗粒的物理性质对流化床传热的影响。在床上注入热空气（50和100摄氏度）以使颗粒流化。结果表明，玻璃颗粒的温度比铝颗粒的温度变化更大。与气粒换热和颗粒对流换热相比，颗粒间换热可以忽略不计。数值分析基于实验结果，我们的模型忽略了颗粒间传热。预测的温度分布与实验结果基本一致。我们还建立了具有尺寸分布的系统阻力模型。此外，我们提出了一个用于大规模计算的相似模型。

The objective of this study is the development of numerical scheme for analyzing the phenomena in dense gas-solid two-phase flows with heat transfer. An infrared thermography was employed to measure the distribution of particle temperature. The experimental results were compared with the numerical results. Our experimental and numerical results are summarized below.ExperimentThe distribution of particle temperature was measured in a 2-D fluidized bed by using an infrared thermography. A spinel window, which can transmit infrared rays, was placed at the center of the front wall. Two different materials (glass and aluminum) of particles were used to study the effect of the physical properties on the heat transfer in the fluidized bed.The hot air (50 and 100 degrees centigrade) was injected in the bed to fluidize the particles. It was found that the temperature of glass particles varied more than that of aluminum particles. It was also found that the inter-particle heat transfer is negligible compared to gas-particle heat exchange and heat transfer by particle convection.Numerical analysisThe inter-particle heat transfer were neglected in our model based on the experimental results. Predicted temperature distribution agreed qualitatively with the experimental results. We also developed a drag force model for the system with size distribution. Further, we proposed a similarity model for large scale computations.