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ISSN Online: 2379-1748

ISBN Flash Drive: 978-1-56700-431-1

ISBN Online: 978-1-56700-430-4

First Thermal and Fluids Engineering Summer Conference
August, 9-12, 2015 , New York City, USA

EFFECT OF CORRUGATED TUBES ON HEAT EXCHANGERS USING NUMERICAL SIMULATIONS

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DOI: 10.1615/TFESC1.fnd.012826

Abstract

Double tube heat exchangers are widely used in the industry due to its simplicity and low cost. They are especially competitive versus shell and tube heat exchangers in high pressure and small duty applications. For certain applications in which one the heat transfer fluid is highly viscous, the flow in the tube could be laminar, reducing notably the global heat transfer coefficient of the heat exchanger. A traditional solution consists of including extended surface on the shell side to reduce its thermal resistance. An alternative solution is the use of corrugated tubes. The corrugations in the tubes force a laminar flow to transform into a turbulent or transition regime, increasing the heat transfer coefficient.
In this work, we conduct numerical simulations of a laminar flow in a simple tube heat exchanger with a corrugated tube surface. The objective is to quantify the increase in the heat duty and the pressure drop for different corrugations, varying the pitch and the depth of the corrugation. The influence of Reynolds number in the heat exchanger will be also addressed, varying this parameter up to values close to the transition to turbulent flow in a smooth tube. For all the analyzed flow cases, the temperature distribution for a cross sectional area across the tube was more homogeneous for the corrugated tubes in comparison to the smooth tube. Moreover, the pressure drop increased as Reynolds number also increased, obtaining that the pressure drop for corrugated tubes was higher than smooth tubes.