Calculations of the time-averaged local heat transfer coefficients in circulating fluidized bed
- Huzhong Univ. of Science and Technology, Wuhan, Hubei (China). National Lab. of Coal Combustion
The great potential to burn a wide variety of fuels and the reduced emission of pollutant gases mainly SO{sub x} and NO{sub x} have inspired the investigators to conduct research at a brisk pace all around the world on circulating fluidized bed (CFB) technology. An accurate understanding of heat transfer to bed walls is required for proper design of CFB boilers. To develop an optimum economic design of the boiler, it is also necessary to know how the heat transfer coefficient depends on different design and operating parameters. It is impossible to do the experiments under all operating conditions. Thus, the mathematical model prediction is a valuable method instead. Based on the cluster renewal theory of heat transfer in circulating fluidized beds, a mathematical model for predicting the time-averaged local bed-to-wall heat transfer coefficients is developed. The effects of the axial distribution of the bed density on the time-average local heat transfer coefficients are taken into account via dividing the bed into a series of sections along its height. The assumptions are made about the formation and falling process of clusters on the wall. The model predictions are in an acceptable agreement with the published data.
- OSTI ID:
- 343666
- Journal Information:
- International Communications in Heat and Mass Transfer, Vol. 26, Issue 3; Other Information: PBD: Apr 1999
- Country of Publication:
- United States
- Language:
- English
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