Numerical analysis of internal recirculation into a radiant tube without internal ignition
Suárez-Castañeda, J. L. (José Luis) | 2014-05-15
This paper presents a numerical analysis using the CFD Fluent (6.3.26 version) program to identify the
effects that can be generated when using radiant tubes with internal recirculation of combustion products,
but with a pre-combustion chamber. The numerical results are validated with an experimental
assembly based on the outlet deviation of gases temperature. These deviations were less than 5 % and
are attributed principality to isolation deficiency in the re-radiant surface.
To independently find the recirculation effect in this tube, the same operational characteristic in the tube
were maintained and an analysis using different windows recirculation widths as well as one without
windows was done. Through this analysis, it was possible to observe the little importance of recirculation
effects when combustion doesn’t occur internally in the tube on the uniformity surface temperature on
the external tube and the emitted energy, but it decrease the system pressure drop slightly although its
magnitude order is very small.