Numerical Study of Nanofluid Irreversibilities in a Heat Exchanger Used with an Aqueous Medium

• Main Authors: Guillermo Efren Ovando-Chacon, Sandy Luz Ovando-Chacon, Abelardo Rodriguez-Leon, Mario Diaz-Gonzalez, Jorge Arturo Hernandez-Zarate, Alberto Servin-Martinez
• Format: Article
• Language: English
• Published: MDPI AG 2020-01-01
• Series: Entropy
• Subjects: nanofluid; heat exchanger; entropy generation; heat transfer; performance evaluation criteria
• Online Access: https://www.mdpi.com/1099-4300/22/1/86

Heat exchangers play an important role in different industrial processes; therefore, it is important to characterize these devices to improve their efficiency by guaranteeing the efficient use of energy. In this study, we carry out a numerical analysis of flow dynamics, heat transfer, and entropy generation inside a heat exchanger; an aqueous medium used for oil extraction flows through the exchanger. Hot water flows on the shell side; nanoparticles have been added to the water in order to improve heat transfer toward the cold aqueous medium flowing on the tube side. The aqueous medium must reach a certain temperature in order to obtain its oil extraction properties. The analysis is performed for different Richardson numbers (<i>Ri</i> = 0.1&#8722;10), nanofluid volume fractions (<i>&#966;</i> = 0.00&#8722;0.06), and heat exchanger heights (<i>H</i> = 0.6&#8722;1.0). Results are presented in terms of Nusselt number, total entropy generation, Bejan number, and performance evaluation criterion. Results showed that heat exchanger performance increases with the increase in <i>Ri</i> when <i>Ri</i> &gt; 1 and when reducing <i>H</i>.