Hydrodynamics of a commercial scale CFB boiler-study with radioactive tracer particles

This paper presents the experimental results with radioactive tracer partic les in an 80 MWth circulating fluidized-bed boiler. Batches of gamma-ray em itting tracer particles were injected into the standpipe. The response curv es of the impulse injection were measured by a set of successive scintillat ion detectors located at different parts of the boiler. The results show th at there are significant differences of the response signals when boiler lo ading changes. A model has been developed to obtain information from the ex perimental data. The particle recirculating rate is obtained by fitting the model to the experimental data. In the same way, the average particle velo cities in the furnace are estimated. The impact of loading on the particle recirculating rate and on the hydrodynamics of the boiler is discussed. (C) 1999 Elsevier Science Ltd. All rights reserved.