Measurement of bubble characteristics in a scale model of a 70 MWe pressurized fluidized bed combustor
- Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Mechanical Engineering
A one-quarter linear scale model of the Tidd 70 MW{sub e} PFBC was constructed. Studies reported previously have shown that the scale model gives local and overall bed expansion values that closely agree with those measured in the PFBC by means of pressure-drop measurements. The cold-scale model was instrumented with light probes embedded in the dowels used to represent the tubes in the boiler. The light probes were used to measure the bubble mean pierced length, bubble frequency, and bubble rise velocity. A probe was positioned in the open area below the tube bank. Measurements were made at u{sub o}/u{sub mf} values between 2.5 and 3.8. In the open area below the tubes, the bubble size and growth rates are smaller than the values predicted from correlations based on atmospheric bubbling beds. This suggests that in a pressurized bed the bubbles either grow more slowly or split as well as coalesce. The bubble size was found to be limited within the tube bank. The bubble velocity is greater than the velocity of a single bubble in an infinite medium, but the bubble velocity was found to be insensitive to the gas superficial velocity. The gas through-flow is closely approximated by the two-phase hypothesis without any bypass flow. This is confirmed by the absence of closely-spaced bubble chains or vertical voids within the tube bank. The bubble behavior is important as it influences both particle and gas mixing through the bed as well as heat transfer to the in-bed tube bundle.
- Sponsoring Organization:
- USDOE Morgantown Energy Technology Center, WV (United States)
- DOE Contract Number:
- FC21-92MC29264
- OSTI ID:
- 357853
- Report Number(s):
- CONF-9705116-; ISBN 0-7918-1557-9; TRN: IM9932%%198
- Resource Relation:
- Conference: 14. international conference on fluidized bed combustion, Vancouver (Canada), 11-16 May 1997; Other Information: PBD: 1997; Related Information: Is Part Of Proceedings of the 14. international conference on fluidized bed combustion: Volume 2; Preto, F.D.S. [ed.] [Canada Centre for Mineral and Energy Technology, Ottawa, Ontario (Canada). Energy Technology Centre]; PB: 647 p.
- Country of Publication:
- United States
- Language:
- English
Similar Records
Verification of the simplified hydrodynamic scaling parameters for commercial pressurized fluidized bed combustors. Part 1: Bubbling fluidized beds
Scaling of pressurized fluidized beds. Quarterly report, October 1993--January 1994