scholarly journals Scale models of a fluidized bed combustor: Simplification of the scaling laws over all flow regimes from bubbling to circulating flow and the scaling of heat transfer. Quarterly report, [April 1, 1992--June 30, 1992]

1992 ◽  
Author(s):  
L.R. Glicksman ◽  
M. Hyre
Keyword(s):  
Heat Transfer ◽  
Fluidized Bed ◽  
Scaling Laws ◽  
Flow Regimes ◽  
Scale Models ◽  
Fluidized Bed Combustor

Experimental Study on Compact External Heat Exchanger for a 4 MWth Circulating Fluidized Bed Combustor

2013 ◽  
Vol 448-453 ◽  
pp. 3259-3269
Author(s):  
Zhi Wei Li ◽  
Hong Zhou He ◽  
Huang Huang Zhuang
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Fluidized Bed ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Cooling Water ◽  
External Heat ◽  
Circulating Ash ◽  
Fluidized Bed Combustor ◽  
External Heat Exchanger

The characteristics of the external heat exchanger (EHE) for a 4 MWth circulation fluidized bed combustor were studied in the present paper. The length, width and height of EHE were 1.5 m, 0.8 m and 9 m, respectively. The circulating ash flow passing the heating surface bed could be controlled by adjusting the fluidizing air flow and the heating transferred from the circulating ash to the cooling water. The ash flow rate passing through the heat transfer bed was from 0.4 to 2.2 kg/s. The ash average temperature was from 500 to 750 °C. And the heat transfer rate between the ash and the cooling water was between 150 and 300 W/(m2·°C). The relationships among the circulating ash temperature, the heat transfer, heat transfer rate, the heat transfer coefficient and the circulating ash flow passing through the heating exchange cell were also presented and could be used for further commercial EHE design.

A Future Trend on Research Scope of Numerical Simulation on Conical Fluidized Bed

2020 ◽  
pp. 401-437 ◽  
Author(s):  
Hirakh Jyoti Das ◽  
Pinakeswar Mahanta ◽  
Rituraj Saikia
Keyword(s):  
Heat Transfer ◽  
Fluidized Bed ◽  
Scale Up ◽  
Future Trend ◽  
Numerical Techniques ◽  
Cfd Modelling ◽  
Mixing Characteristics ◽  
Fluidized Bed Combustor ◽  
Computing Speed ◽  
Conical Fluidized Bed

Fluidized bed technology is a well-established environment friendly technology, by which energy can be generated through combustion and gasification techniques. It is widely prevalent today owing to its excellent heat transfer, mixing characteristics and compactness. The design and scale-up of the fluidized beds are vital to the enhancement of heat transfer and mixing characteristics. However, heat transfer characteristics play a key role in determining the combustion and gasification characteristics. CFD is a technique which helps to optimize the design and operation of fluidized bed combustor and gasifiers. Enhancement of computing speed and numerical techniques has led to CFD being used as a widely implemented tool to provide a bridge between laboratory scale and industrial study. In this chapter, a comprehensive review of CFD modelling and experimental study on the conical fluidized bed has been carried out. Primarily this chapter demonstrates probable future accomplishments and identifies trends and regions where further research is required.

Heat transfer to horizontal tubes immersed in a fluidized-bed combustor

1987 ◽  
Vol 52 (2) ◽  
pp. 149-159 ◽  
Author(s):  
N.S. Grewal ◽  
J. Menart ◽  
D.R. Hajicek ◽  
B.J. Zobeck
Keyword(s):  
Heat Transfer ◽  
Fluidized Bed ◽  
Horizontal Tubes ◽  
Fluidized Bed Combustor

The Performance of a Loop Seal in a CFB Boiler

2006 ◽  
Vol 128 (2) ◽  
pp. 135-142 ◽  
Author(s):  
Andreas Johansson ◽  
Filip Johnsson ◽  
Bengt-Åke Andersson
Keyword(s):  
Heat Transfer ◽  
Flow Pattern ◽  
Fluidized Bed ◽  
Scaling Laws ◽  
Circulating Fluidized Bed ◽  
Vertical Direction ◽  
Scale Model ◽  
Corrosive Environment ◽  
Cfb Boiler ◽  
Load Conditions

High in-bed heat transfer and low corrosive environment imply that the loop seal of a circulating fluidized bed (CFB) boiler is an advantageous location for superheaters. In order to increase the knowledge on the flow pattern and the heat transfer distribution to the tubes within a loop seal, measurements were performed in the loop seal of a 30MW CFB boiler as well as in a 1∕3 scaled-down seal operated according to simplified scaling laws. The scale model measurements show that the solids recirculation flux can be maintained with a substantial decrease of the fluidization flow in the seal compared to that currently used at full load conditions. It was also possible to significantly decrease the fraction of the bottom of the seal that was fluidized without affecting the solids flux through the seal. A gradient in the solids flow were detected in the vertical direction.

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