Comparison of the Transient Behaviors of Bubbling and Circulating Fluidized Bed Combustors

This work compares the transient behaviors of flue gas sides large-scale bubbling and circulating fluidized bed (BFB CFB, respectively) boilers. For this purpose, a dynamic model in-furnace side combustors presented validated by authors in former is used to simulate two industrial units. The results show that for load changes heat transfer waterwalls stabilizes more rapidly BFB Differences stabilization time between dense top furnace are observed both units, caused distribution solids along combustor: contains than regions located higher up and, therefore slower respond, with times around 15 minutes, as compared range 1–8 minutes upper furnace. behavior accentuated BFB, where all remain bottom region. effect characteristic main mechanisms (fluid-dynamics, fuel conversion, transfer) on performance CFB units has been explored expressed through proposed mathematical relationships.