Proceedings of the
Second International Energy 2030 Conference,
November 4-5, 2008, Abu Dhabi, U.A.E.
Improvement of Fluidized Bed Bottom Ash Cooler Performance in CFB Boiler
Ryo Samuel Amano
University of Wisconsin-Milwaukee, USA
Xiaofeng Lu
Chongqing University, China
Abstract
Fluidized bed combustion offer significant potential for uniform thermal field and low NOx emission.
Sulfur in the fuel can also be captured in the bed. However, the pressure drop across the bed is a concern
and must be determined. This paper provides the selective fluidized bed bottom ash cooler behavior from
a 410 t/h CFB boiler. A visual cold experimental apparatus at the ratio of 1:10 was set up to determine the
global flow behavior. Under the condition of the steadily operating furnace, a series of cold experimental
tests were completed with bed materials of ash floater. The relationship of various parameters, such as the
velocity of the fluidizing air, the bed pressure drops, the height of the static bed materials in each chamber
of the bottom ash cooler, and the relationship of the ash inlet pipe pulse air and the velocity of ash flowing
from the furnace to the bottom ash cooler, were obtained. The numerical simulation of the cold flow
characteristics on the gas-solid flow in the bottom ash cooler simulating the cold experimental tests were
also carried out and are presented here. The results of the primary experiments and simulation indicate that
according to the variation of the bed pressure drop, the velocity of the fluidizing air of each chamber could
be adjusted to keep the steady operation of the selective fluidized bed bottom ash cooler. Thus modeling
studies can assist in the design and development of fluidized bed combustors.
