Abstract
Background: Pipe-type heat exchangers are commonly used in industrial
applications to facilitate heat transfer between two fluids at different temperatures
without mixing them.
Method: In this study, turbulators were employed in a counterflow concentric pipetype
heat exchanger. Water at a flow rate of 50 l/h and a temperature of 298.14 K, and
air at a temperature of 350 K were directed through the inner pipe. The different stages
of circular turbulators placed inside the inner pipe were numerically investigated using
the feasible κ-ε turbulence model. Heat transfer characteristics were examined for a
turbulator-free heat exchanger and for turbulator-heat exchanger models with helical
turbulators of 25, 50, 75, and 100 mm pitch at Reynolds numbers ranging from 4000
to 26000. The governing equations for three-dimensional and turbulent flow conditions
in a steady state were solved using a computational fluid dynamics program
based on the finite volume method. Temperature distributions and velocity contours in
the heat exchanger were generated using the data obtained from numerical analysis.
Additionally, predictions were made using artificial neural networks.
Results: The results revealed that the highest enhancement in heat transfer, amounting to
233.08% compared to the empty tube case, was achieved with the 25 mm pitch turbulator.
Conclusion: The predictions made using artificial neural networks were in good
agreement with the numerical analysis results. The designed turbulators for the heat
exchanger model promoted turbulent flow, increased the heat transfer area, and led to
an improvement in heat transfer.
Graphical Abstract
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