Heat Transfer and Pressure Drop Analysis of Double Tube Heat Exchanger with and Without Metal Foam in Annular Space

Abstract

AbstractMetal foam can be used to create a high-surface area to exchange more heat which will reduce size of heat exchange device. It is becoming more popular due to its weight-saving and impact absorbing characteristics as compared to traditional approaches. It can be used in heat exchangers for various applications to improve heat transfer characteristics. Present work is carried out in two parts as analysis of a circular pipe 1.5 m long having ID 40 mm and OD 45 mm with metal foam firstly, and in other part, analysis of double tube heat exchanger with metal foam in annular space is done. The numerical analysis was further extended to 1.5 m long heat exchanger with inner tube of SS (ID 9.5, OD 12.7 mm) and outer tube of GI (ID 28, OD 33.8 mm). Nickel metal foam having 0.9 porosity and pore density 20 PPI was used A geometry with foam was generated in Creo, and then, the simulation was carried out in Ansys fluent flow using the K-omega (2 equation) viscous model which yielded in higher heat transfer coefficients. It has been noticed that the heat transfer coefficient (HTC) was about 1.5 times higher for single circular tube after inserting a metal foam. In double tube heat exchanger, HTC was found to be 2–2.5 times higher for flow through annular space with metal foam which increased overall HTC by approximately two times. Pressure drop is higher when metal foam was inserted in both the cases.KeywordsMetal foamAnnular spacesDouble tube heat exchangerHeat transfer coefficient