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Vijay Gagare,
Ritesh Ware,
Sarthak Kalbande,
Abhijeet Malge,
Pramod Kothmire,
- UG Scholar, Department of Mechanical Engineering, MIT Academy of Engineering, Alandi, Pune, Maharashtra, India
- UG Scholar, Department of Mechanical Engineering, MIT Academy of Engineering, Alandi, Pune, Maharashtra, India
- UG Scholar, Department of Mechanical Engineering, MIT Academy of Engineering, Alandi, Pune, Maharashtra, India
- Professor, Department of Mechanical Engineering, MIT Academy of Engineering, Alandi, Pune, Maharashtra, India
- Associate Professor, Department of Mechanical Engineering, MIT Academy of Engineering, Alandi, Pune, Maharashtra, India
Abstract
Double-pipe heat exchangers remain one of the most widely adopted thermal devices because of their simple construction, operational reliability, and ease of maintenance. Nevertheless, their performance is often constrained by the limited heat transfer area of smooth tubes and the long-term challenges associated with metallic materials, including corrosion, scaling, and structural weight. Recent advances in thermally conductive polymer composites provide an opportunity to overcome these limitations by replacing conventional metals with lightweight, corrosion-resistant materials whose thermal properties can be tailored through conductive fillers. Motivated by this concept, the present study investigates the combined influence of annular fins and graphite-filled epoxy composite tubes on the thermo-hydraulic performance of a double-pass concentric double-pipe heat exchanger operating under counter-flow conditions. A three-dimensional conjugate heat transfer model was developed in ANSYS Fluent using the realizable k–ε turbulence model to simulate turbulent flow, heat conduction through the tube wall, and fluid–solid thermal interaction. Cold water entered the inner tube at 25°C, while hot water flowed through the annulus at 70°C, with flow rates varied from 1 to 10 LPM to evaluate performance over a broad operating range. The annular fins intensified turbulence and disrupted thermal boundary layers, resulting in improved convective heat transfer, while the graphite-filled epoxy tube provided enhanced thermal conduction compared with neat polymers without compromising its lightweight and corrosion-resistant characteristics. Although fin-induced turbulence increased pressure losses, the corresponding improvement in heat transfer produced a favourable thermo-hydraulic balance throughout the investigated operating range. The study demonstrates that integrating passive geometric enhancement with thermally conductive graphite-filled epoxy composites offers an effective strategy for developing compact, lightweight, and durable heat exchangers capable of delivering high thermal performance in chemically aggressive and weight-sensitive industrial applications.
Keywords: Double-pass heat exchanger; Annular fins; Graphite-filled epoxy composite; Polymer heat exchanger; CFD analysis; Thermo-hydraulic performance; Heat transfer enhancement.
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Journal of Polymer & Composites
| Volume | 14 | |
| 05 | ||
| Received | 09/07/2026 | |
| Accepted | 06/08/2026 | |
| Published | 01/10/2026 | |
| Publication Time | 84 Days |