Heat transfer characteristics on a vertical tube in a fluidized bed combustor has been investigated based on an appropriate model selected involving radiant heat transfer.
The combustor is composed of a fluidized bed zone of 15cm in diameter, 100cm in height and a free board zone of 25cm in diameter, 50cm in height.
Experimental measurements have been carried out with varying operating conditions - particle size 0.33-0.78 mm, air velocity 60-190cm/sec (bed temperature basis), bed temperature 800-850℃ - as wall as with as with different radial position of vertical heat transfer tube.
An analytical equation describing the relationship between the heat transfer coefficient (ht) associated with radiation effect is derived as a function of several variables including gas film thickness.
From the experimented results, correlating equations between dimensionless groups characterizing heat transfer through tube wall are introduced.
