Title: Exergy analysis and optimisation of collector dimensions in a solar chimney power plant using entropy generation minimisation method

Authors: Amir Arefian; Abbas Abbassi; Reza Hosseini

Addresses: Amirkabir University of Technology, Mechanical Engineering Department, 424, Hafez Ave, P.O. Box 1591634311, Tehran, Iran ' Amirkabir University of Technology, Mechanical Engineering Department, 424, Hafez Ave, P.O. Box 1591634311, Tehran, Iran ' Amirkabir University of Technology, Mechanical Engineering Department, 424, Hafez Ave, P.O. Box 1591634311, Tehran, Iran

Abstract: The purpose of this study is to optimise the dimensions of the collector in a solar chimney power plant with entropy generation minimisation (EGM) method. Projection method, based on second-order finite difference discretisation, is developed to solve the coupled equations of continuity, momentum and energy of laminar natural convection in a fully staggered grid. Numerical solution showed that the irreversibility owing to heat transfer is dominant in solar collector and the chimney has minor role in total entropy generation. On the basis of temperature field, local entropy generation and Bejan number distribution in the system, an analytical solution for total entropy generation is developed and compared with numerical results for different Rayleigh numbers and collector height to radius ratios. The study showed that total entropy generation is proportional to square of Rayleigh number and it is inversely proportional to collector height to radius ratio.

Keywords: solar chimney power plants; natural convection; EGM; entropy generation minimisation; projection method; exergy analysis; optimisation; solar collectors; solar power; finite difference discretisation.

DOI: 10.1504/IJEX.2014.065707

International Journal of Exergy, 2014 Vol.15 No.3, pp.328 - 343

Received: 26 Feb 2013
Accepted: 08 Oct 2013
Published online: 30 Apr 2015 *

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