The purpose of this investigation is to analyze the effects of
the holed-pin fins which are located in the entrance of a
concentric heat exchanger on heat transfer and pressure loss.
The outer surface of the inner tube is maintained at constant
temperature (100 C) by continuous contact with saturated
water vapor introduced and filled into the annular space
between the inner and outer tubes and discharged by a channel,
like a teapot. The surface temperatures of the inner pipe, inlet
and outlet temperatures of the air and pressure loss through the
pipe are measured. The measurements are carried out for the
Reynolds number ranged from 6000 to 12000. The design
parameters are considered as the distance between the
turbulators (s = 20, 30, 40 mm), hole diameter that is drilled on
the pin fins (d = 6, 9, 12 mm) and the positions of the holes (top
of the plate; namely Type T and center of the plate; namely
Type C). Nusselt number and friction factor are found out based
on the measurements. The comparison between the results of
tabulated pipe and empty pipe, by means of Nusselt number
and friction factor are done in order to show the effect of the
turbulators in the concentric tube.
Papers presented to the 12th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Costa de Sol, Spain on 11-13 July 2016.