多旋风分离器及返料系统是保证循环流化床锅炉高效燃烧的关键设备,是循环流化床大型化研究的关键部件之一。本文采用电容层析成像技术结合压力测量,对多旋风分离器返料系统内部气固两相流场进行实验研究。通过六旋风分离器冷态循环流化床电容层析成像浓度分布和压力测量,揭示循环流化床多分离返料系统颗粒流动分配特性,为循环流化床锅炉大型化,特别是超临界锅炉多旋风分离器的优化布置提供科学依据,基础实验数据库和技术手段,研究内容将电容层析成像技术的应用扩展到工程设计中,对实际工程起到理论指导的作用。
To understand the hydrodynamic behaviour of a circulating fluidised bed(CFB),a cold CFB test rig with symmetrical arrangements of six cyclone separators on the top of the boiler,three separators in each side has been built and the characteristics of solid distribution in the standpipe of cyclone are investigated by electrical capacitance tomography(ECT).The objective of this research is to investigate the cold gas-solids distribution among the six cyclones by ECT measurement and compared with pressure-drop measurement.The experiment result includes the effect of fluidisation velocity and boiler load(initial material weight) on the solids flux through the inlet of cyclones.The preliminary experiment result demonstrates that the three cyclone separators have different solids distribution along one side of the CFB.The analysis results will be used to scale up a CFB boiler from small scale to large scale,i.e.,super-pressure circulating" fiuidised bed with multi-cyclone separators.