scholarly journals Heat transfer in high temperature fluidized beds with immersed tubes for coal combustion service. Final report, October 1, 1977-March 31, 1981

1984 ◽  
Author(s):  
J. R. Welty
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Coal Combustion ◽  
Fluidized Beds ◽  
Final Report

Freeboard heat transfer in high-temperature fluidized beds

1987 ◽  
Vol 53 (3) ◽  
pp. 187-194 ◽  
Author(s):  
S. Biyikli ◽  
K. Tuzla ◽  
J.C. Chen
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Fluidized Beds

Analysis of the Heat Transfer Mechanism in High-Temperature Circulating Fluidized Beds by a Numerical Model

2002 ◽  
Vol 124 (1) ◽  
pp. 34-39 ◽  
Author(s):  
Qiao He ◽  
Franz Winter ◽  
Ji-Dong Lu
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Radiative Heat Transfer ◽  
Fluidized Beds ◽  
Radiative Heat ◽  
Total Heat ◽  
Circulating Fluidized Beds ◽  
Total Heat Transfer

A general numerical model is presented here to describe the complex fluid dynamics and the heat transfer process in high-temperature circulating fluidized beds (CFBs). The core-wall concept is used to describe the gas-solid flow in the dilute phase section of CFBs. The variation of the thickness of the wall layer along the height direction is considered in the fluid dynamic model in order to approach the practical conditions. Three components of heat transfer, i.e., the particle-convective heat transfer, the gas-convective heat transfer, and the radiative heat transfer, and their contributions to the total heat transfer coefficient are investigated. The influences of some operating parameters on the total heat transfer and its components are predicted. Detailed information about the mechanism of heat transfer is discussed. The radiative heat transfer accounts for about 30∼60% of the total heat transfer in high temperature CFBs. It gradually increases along the height direction of the furnace. When the contribution of particle convection increases, the contribution of gas convection decreases, and vice versa. Particle size shows a significant effect on the radiative heat transfer and the convective heat transfer. High bed and wall temperatures will primarily increase the radiative heat transfer.

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