The Design, Analysis, and Fabrication of an Additively Manufactured Twisted Tube Heat Exchanger

Abstract

The rapid development of Additive Manufacturing (AM) technologies has provided engineers with new methods to design and fabricate complex mechanisms. AM offers unique methods to allow for integration and simplification of components, reduced manufacturing time, fabrication of complex-shaped objects, improvements upon existing designs, and extending the creative design space which engineers rely on for ingenuity. For many applications, heat exchanger performance can be improved by reducing its size, increasing the overall heat transfer coefficient and surface area, and making more efficient use of the mechanical structure for heat exchange. Traditional manufacturing often limits or prohibits many of these enhancements due to increased manufacturing and assembly costs. This study explored using AM to design and fabricate a compact twisted tube stainless steel shell and tube heat exchanger that would improve upon all of the features just mentioned. This paper discusses the design of the heat exchanger and the AM technique used to fabricate a prototype. The manuscript will show via CFD analyses, how the heat transfer area of the unit was improved 18% and the overall heat transfer coefficient as increased by 40% over a traditional round tube heat exchanger with an identical footprint. Further, the study will show how AM was leveraged to combine five manufacturing steps into one to fabricate a prototype, fully functional twisted tube heat exchanger.