To improve the load regulation ability of the circulating fluidized bed (CFB) unit, investigating the hydrodynamic characteristics of the gas-solid flow in the CFB loop during such processes is of vital importance. In this work, based on the mass and pressure balance in the whole loop, a one-dimensional dynamic model on the gas-solid flow in the full-loop of an industrial CFB was established. In particular, the solid mass flow rate at the dust exit was correlated with the total inventory of the cyclone, and the re-circulating rate to the furnace was depicted by the pressure drop in the loop seal. The model was validated by the field test data of a 350 MW supercritical CFB boiler during a load increasing process. Subsequently, the impact of the load change rate and operating bed pressure on the hydrodynamic performance in the whole loop of the CFB boiler during the load reduction process were analyzed. The results show that the bed pressure in the furnace will fluctuate more violently when the load change rate increases, while the operating bed pressure has a weak effect on the load regulation process. These conclusions can provide theoretical guidance to the variable load operation of the CFB boiler.

为了提高循环流化床（CFB）单元的负载调节能力，研究CFB回路中气固两相流动的流体动力学特性至关重要。在这项工作中，基于整个回路的质量和压力平衡，建立了工业CFB全回路中气固流的一维动力学模型。尤其是，粉尘出口处的固体质量流速与旋风分离器的总库存量相关，并且通过环封中的压降描述了回炉的再循环率。在负荷增加过程中，通过350 MW超临界CFB锅炉的现场测试数据验证了该模型。随后，分析了负荷变化率和工作床压力对CFB锅炉减负荷过程全循环水动力性能的影响。结果表明，当负荷变化率增加时，炉内床压波动更大，而工作床压对负荷调节过程的影响较弱。这些结论可以为CFB锅炉的变负荷运行提供理论指导。