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 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.
Analysis of the Heat Transfer Mechanism in High-Temperature Circulating Fluidized Beds by a Numerical Model
Contributed by the Advanced Energy Systems Division for publication in the JOURNAL OF ENERGY RESOURCES TECHNOLOGY. Manuscript received by the AES Division, November 3, 2000; revised manuscript received November 30, 2001. Associate Editor: D. L. O’Neal.
- Views Icon Views
- Share Icon Share
- Cite Icon Cite
- Search Site
He , Q., Winter, F., and Lu, J. (March 25, 2002). "Analysis of the Heat Transfer Mechanism in High-Temperature Circulating Fluidized Beds by a Numerical Model ." ASME. J. Energy Resour. Technol. March 2002; 124(1): 34–39. https://doi.org/10.1115/1.1446473
Download citation file:
- Ris (Zotero)
- Reference Manager