Radiation Heat Exchange between Fluidized Particles and Heated Surface in a Fluidized Bed.

This paper deals with mechanisms of heat transfer in a gas–solid fluidized bed. Heat transfer due to heat exchange by direct contact from a heat transfer tube immersed in the bed to fluidized particles was studied by means of visualization of contact of the fluidized particles to the heat transfer surface. The results show that the duration of contact of fluidized particles was almost uniform over the tube circumference and was hardly affected by the flow rate of fluidizing gas. On the other hand, the contact frequency between the particles and heat transfer tube was evidently influenced by the gas flow rate and particles diameter, as well as the location on the tube circumference. Using the visualized results, the amount of heat conducted to fluidized particles during the contact was estimated. This result showed that unsteady heat conduction to the fluidized particles plays an important role in the heat transfer, especially at the condition of incipient fluidization.

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Influence of window and door position at the wall on the radiation heat exchange in relation to interior room surfaces

Energy and Buildings ◽

10.1016/s0378-7788(02)00162-7 ◽

2003 ◽

Vol 35 (6) ◽

pp. 533-538 ◽

Cited By ~ 1

Author(s):

Dimitrije Lilić

Keyword(s):

Heat Exchange ◽

Radiation Heat ◽

Radiation Heat Exchange

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Numerical modeling of radiation heat exchange in combustion chambers and heat exchangers of power installations

E3S Web of Conferences ◽

10.1051/e3sconf/202020903018 ◽

2020 ◽

Vol 209 ◽

pp. 03018

Author(s):

Nikolay Moskalenko ◽

Ibragim Dodov ◽

Azat Akhmetshin

Keyword(s):

Numerical Modeling ◽

Heat Exchange ◽

Radiation Heat Transfer ◽

Combustion Products ◽

Spectral Lines ◽

Spectral Transmission ◽

Radiation Heat ◽

Combustion Chambers ◽

Two Phase ◽

Radiation Heat Exchange

The application of numerical modeling is considered to solve the problems of radiation heat exchange in structurally inhomogeneous two-phase media which are realized during the combustion of fuel in boiler units atmospheric emissions from air carriers when they move at supersonic speeds. The optically active ingredients of the gas phase of the combustion products have a sharp selection of spectral absorption lines (radiation) which causes a difference in the spectral transmission functions for selective radiation from the spectral transmission functions for non-selective radiation (gray body). In the presence of a dispersed phase of the combustion products acute selection is subjected to such a parameter of the radiation propagation medium as the probability of quantum survival. The number of spectral lines determining the spectral transmission functions increases with temperature and is determined by hundreds of thousands of lines at high temperatures. In this paper we consider a closed simulation of radiation heat transfer in combustion chambers when the temperature field in the combustion chambers is calculated first and then the flux of thermal radiation to the tube heat-receiving surfaces.

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