Evaluation of the Fluid-Dynamically Down-Scaled Model of a ~200 MWth CFB Boiler

Experimental campaigns in commercial CFB boilers are often limited to some extent by safety demands, narrow operational range imposed by requirements on safe and cost-efficient operation, limited access to in-situ measurements and lack of experimental methods due to harsh in-furnace environment. The use of fluid-dynamical scaling laws allows the design of lab-scale experimental setups which can operate under ambient conditions, while still resemble mixing and fluid-dynamics under hot conditions and allowing for a large span in operational condition, detailed measurements and visual observations of the flow.

This work presents first operating and measurement experience from a 1/13 fluid-dynamically down-scaled model of a 200 MW_th CFB boiler, which is operated according to Glicksman’s simplified set of scaling parameters for fluid-dynamical scaling. Having this, the measured vertical profile of solids concentration is validated by comparing with corresponding data from the full-scale boiler. The external solids circulation rate is directly measured in the cold flow model and values obtained for the industrial cases resembled are studied. Finally, the size distribution of the bed material in different parts of the unit is also studied.