Novel usage of the curved rectangular fin on the heat transfer of a double-pipe heat exchanger with a nanofluid

• Published in: Case studies in thermal engineering Vol. 35; p. 102086
• Main Authors: Jalili, Bahram, Aghaee, Narges, Jalili, Payam, Domiri Ganji, Davood
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.07.2022; Elsevier
• Subjects: Convection heat transfer; Double-pipe heat exchanger; Nanofluid; Turbulent flow; Convection heat transfer; Turbulent flow; Nanofluid; Double-pipe heat exchanger
• ISSN: 2214-157X; 2214-157X
• DOI: 10.1016/j.csite.2022.102086

The convection heat transfer in a countercurrent double-tube heat exchanger with various fins in a turbulent flow is investigated. The suitable heating or cooling process of fluids is the effective use of the double-pipe heat exchanger. We use water-aluminum oxide nanofluid and water-titanium dioxide at four concentrations (0.4%, 2%, 4%, 6%) as the cold fluid in the inner tube and water as the hot fluid in the annular space. The single-phase model for nanofluid modeling and the standard k-ε model with scalable wall function for simulating the turbulent flow is utilized. To better examine this novel geometry, its performance is compared with simple and rectangular-finned geometries. The results show that the water aluminum oxide nanofluid has a better convection heat transfer coefficient than water titanium dioxide and pure water. Raising the nanofluid concentration from 0.4% to 6% increases the convection heat transfer coefficient by 12%. Heat exchangers with a rectangular and curved fin have 81% and 85% better efficiency than the heat exchanger without a fin. The novel geometry causes a smaller pressure drop despite its higher convection heat transfer coefficient. Also, it is shown that with raising the Reynolds number and nanofluid concentration, the pressure drop increases.