Cold Experiment On A Circulating Fluidized Bed Multi-Generation System

A cold model of a circulating fluidized bed multi-generation system is built. It consists of a circulating fluidized bed of 400mm in diameter and 6000mm in height and a combined moving bed of 476mm in diameter and 2000mm in height. A pneumatic distribution valve is used to adjust circulating ash flows between the two beds. Experiments mainly on the pneumatic distribution valve and large particles flow from the moving bed to the lift of the CFB are made and the results are described in the paper.Experiments on the load-adjustment of the circulating fluidized bed multi-generation system are conducted under different operating conditions. Experimental results show that the pneumatic distribution valve has good load-adjustment capability. This feature ensures stable operation of the circulating fluidized bed multi-generation system at full or partial loads when the moving bed gasifier is operated or is in standby mode. The pneumatic distribution valve can be used as gas-sealing device between the circulating fluidized bed and the moving bed.Large particles from moving bed can enter the lift of the CFB successfully through loop-seal recycle device. The effect of large particles flowrate, solids circulating flowrate and air flow fluidization velocity on large particles recycle property are analyzed through experiments.The circulating fluidized bed multi-generation system is modified based on the experiments. Experimental results after modification show that solids circulating flowrate is crucial for stable operation of the system.On the basis of the experiments, some features of the circulating fluidized bed multi-generation system such as pressure distribution along the circulating system, load-adjustment of the pneumatic distribution valve and the design method of gasifier are discussed.