| 1. |
- Andersson, Bengt-Åke, et al.
(author)
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Bed-to-wall heat transfer in a 10m2 bubbling fluidized bed
- 1994
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In: Congreso Europeo de Fluidización. - 8478060936 ; 1, s. 251-260
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Conference paper (peer-reviewed)abstract
- The heat transfer is measured on the membrane tube wall in contact with a bubbling fluidized bed boiler. Measurements are carried out by heat transfer meters through holes in the wall both in the bed and above the bed in the splash zone and freeboard. Heat transfer coefficients are given and compared with previous measurements of material loss at the same wall and under the same conditions (typical for a fluidized bed boiler)
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| 2. |
- Andersson, Bengt-Åke, et al.
(author)
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Experimental methods of estimating heat transfer in circulating fluidized bed boilers
- 1992
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In: International Journal of Heat and Mass Transfer. - 0017-9310. ; 35:12, s. 3353-3362
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Journal article (peer-reviewed)abstract
- Four different experimental methods have been used for the estimation of the bed-to-membranewall heat transfer in a 12 MW,, circulating fluidized bed boiler. The methods are compared for a case ofnormal operating conditions and the measured heat transfer coefficients are presented. In the central partof the combustion chamber where most of the cooling surface is located, the cross-sectional averagesuspension density normally varies in the range of 10-20 kg m -’ and the heat transfer coefficient is around130 W m ’ K-’ with a scatter of + 15% due to the different methods. The methods are critically analyzedand the heat transfer data are compared with relevant literature data.
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| 3. |
- Andersson, Bengt-Åke, et al.
(author)
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Local lateral distribution of heat transfer on tube surface on membrane walls in CFB boilers
- 1993
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In: Proc of the 4th International Conference on Circulating Fluidized Beds. ; , s. 311-318
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Conference paper (peer-reviewed)abstract
- The wall to bed heat transfer was investigated in a 12 MWth CFB boiler at different locations in the combustion chamber and under various operating conditions. At high levels in the furnace the lateral distribution of heat flow to the tube and fin was found to be a result of radiation from the hot bed bulk, especially at low bulk densities. The local heat flow to the fin decreased considerably with decreasing height in contrast to the heat flow to the crest of the tube. This is due to the large down-flow of particles in the fin region and the growth of the boundary layer. The average heat transfer coefficient across the membrane wall was found to decrease with decreased bulk density, but at low bulk densities the decrease is very small since radiation dominates heat transfer.
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| 4. |
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| 5. |
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| 6. |
- Leckner, Bo G, 1936, et al.
(author)
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Characteristic features of heat transfer in circulating fluidized bed boilers
- 1992
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In: Powder Technology. - 1873-328X .- 0032-5910. ; 70:3, s. 303-314
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Journal article (peer-reviewed)abstract
- The characteristic features of heat transfer in circulating fluidized bed boilers are described. First, the conditionsfor heat transfer are listed. Then, examples of measurements from the research boiler at Chalmers Universityof Technology are presented, including thermal and fluid-dynamic boundary layers as well as heat transfercoefficients measured with a heat flow meter and with thermocouples mounted on the tube walls of the boiler.Differences in heat transfer efficiency of the fins and of the tubes of a membrane tube wall are shown. Finally,heat transfer mechanisms are briefly discussed, and the influence of the macroscopic flow pattern caused byexit, secondary air, etc. is indicated.
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| 7. |
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