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本文基于颗粒动理学理论建立了流化床中的欧拉双流体模型,采用了单气泡沿壁面运动物理模型,从颗粒分布特性、温度分布特性和瞬时传热特性三个方面对超临界水流化床和气固流化床的床层与壁面间传热特性进行了对比研究。研究表明,相同条件下,相对于气固流化床,超临界水流化床中气泡的直径和上升速度都较小;超临界水流化床中床层与壁面间的传热系数与颗粒浓度呈反相关关系,而对于气固流化床则是正相关关系;并且不同于气固流化床,超临界水流化床床层与壁面间传热系数在颗粒浓度较低处对表观速度变化比较敏感。
In this paper, the Euler bi-fluid model in fluidized bed was established based on the particle kinetic theory. The physical model of single bubble along the wall was used to analyze the characteristics of particle distribution, temperature distribution and instantaneous heat transfer. The heat transfer characteristics between the bed and the wall of the bed and the gas-solid fluidized bed are compared. The results show that under the same conditions, the diameter and the rising speed of the bubbles in the supercritical fluidized bed are small compared with the gas-solid fluidized bed. The heat transfer coefficient between the bed and the wall in the supercritical fluidized bed Concentration is inversely related to the gas-solid fluidized bed is a positive correlation; and different from the gas-solid fluidized bed, supercritical water fluidized bed bed and wall heat transfer coefficient at a lower particle concentration on the apparent Speed changes more sensitive.