Title: Estimation of operational costs due to entropy generation in a vertical annulus

Authors: Omid Mahian; Hakan F. Oztop; Ahmet Z. Sahin; Somchai Wongwises

Addresses: Young Researchers and Elite Club, Mashhad Branch, Islamic Azad University, Mashhad, Iran ' Technology Faculty, Department of Mechanical Engineering, F?rat University, Elazig 23119, Turkey ' Mechanical Engineering Department, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia ' Fluid Mechanics, Thermal Engineering and Multiphase Flow Research Lab. (FUTURE), Department of Mechanical Engineering, Faculty of Engineering, King Mongkut's University of Technology Thonburi, Bangmod, Bangkok 10140, Thailand

Abstract: The study of flow and heat transfer in a vertical annulus is important due to its applications in the cooling of reactors, industrial heat exchangers, microelectronic devices, and so forth. The aim of the present work is to estimate the operational costs due to entropy generation in an annulus with isoflux boundary conditions. For this purpose, the governing equations are simplified and solved analytically to obtain the entropy generation distribution in the annulus. Using the results obtained by the entropy generation analysis, the operational costs due to entropy generation are calculated for various radius ratios and different quantities of the flow parameters involved in the problem. The results of this study can be helpful in the design of such heat exchangers to reduce the operational costs caused by the irreversibilities.

Keywords: operational costs; isoflux heat exchangers; entropy generation; refrigerant flow; analytical solutions; vertical annulus; heat transfer; irreversibilities.

DOI: 10.1504/IJEX.2013.058103

International Journal of Exergy, 2013 Vol.13 No.4, pp.472 - 486

Available online: 08 Dec 2013 *

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