Abstract:

Gas-solid circulating fluidized bed (CFB) has been widely used in many fields due to its good mixing, heat transfer, mass transfer and reaction characteristics as well as advantages of large processing capacity and continuous production. CFB is a circulating loop composed of several units, and all the units are coupled and interacted with each other. Therefore, the full-loop simulation, in which the whole CFB system is chosen as the simulation object, is more conducive to obtain accurate and comprehensive results and has advantages in revealing the flow dynamics in the CFB system and in studying the interactions inside the unit between the unit and between the unit and the system. This kind of full-loop simulation has been emerged as a promising research method in the recent decade for the CFB system. The present work will conduct review on the research progress of full-loop simulation, and have in-depth introduction on the application of such simulation method and its relating model and model characteristics. For the CFB, a system with multi flow patterns, it is necessary to establish the multi flow physical model (e.g. interphase drag model, model for the solid pressure) for the full-loop simulation of the CFB system. With the improvement of computing capacity and the development of physical modeling, the full loop simulation method will play an increasingly important role.

Key words: gas-solid circulating fluidized bed, full-loop, numerical simulation, two-phase flow

摘要：

气固循环流化床具有良好的混合、传热、传质、反应特性，同时还具有处理量大、可连续生产等优点，在众多领域均有广泛应用。气固循环流化床是一个由多个单元连接组合形成的循环回路，各单元间相互耦合、相互影响。对整个循环流化床系统进行全回路数值模拟，不仅能够获得更全面和详实的结果，而且在揭示系统流动规律和探究各单元内、单元间、单元与系统间的相互作用上具有独特优势。近十年来，以气固循环流化床全系统为模拟对象的全回路数值模拟研究逐渐兴起。本文对气固循环流化床全回路数值模拟方法的研究进展进行综述，对该方法的应用情况进行详细介绍，并对方法中采用的模型及相应特点进行逐一分析。循环流化床全回路系统同时存在多种流态，有待于建立适用于全回路系统的多流态物理模型（气固曳力模型与固相应力模型）。随着计算能力的提高以及物理建模的不断发展，全回路模拟方法将不断完善并发挥出更大的作用。

关键词: 气固循环流化床, 全回路, 数值模拟, 两相流