Effect of working-fluid mixtures on organic Rankine cycle system performance : heat transfer and cost analysis

dc.contributor.authorOyewunmi, O.A.
dc.contributor.authorMarkides, C.N.
dc.date.accessioned2016-07-19T07:17:46Z
dc.date.available2016-07-19T07:17:46Z
dc.date.issued2015
dc.description.abstractPapers presented to the 11th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 20-23 July 2015.en_ZA
dc.description.abstractA thermodynamic limitation of single-component working fluids in organic Rankine cycles (ORCs) is the large exergy destruction (and, consequently, useful power loss) associated with evaporation and condensation. Due to their non-isothermal phase-change behaviour, non-azeotropic working-fluid mixtures have shown reduced exergy losses, leading to improved cycle efficiencies and power outputs. These benefits are exclusively observed from a thermodynamic perspective. The present paper considers the effects of selecting such working-fluid mixtures on heat transfer performance, component sizing and system costs compared with those of pure fluids; a mixture of n-pentane and n-hexane is selected. While the fluid-mixture cycles do indeed allow higher efficiencies and the generation of higher power outputs, they require larger evaporators, condensers and expanders; thus, the resulting ORC systems are more expensive than those based on the pure fluids. While a working-fluid mixture (60% n-pentane + 40% n-hexane) leads to the thermodynamically optimal cycle, a pure n-pentane ORC system has reduced costs of 37% per unit power output over the thermodynamic optimum.en_ZA
dc.description.librarianam2016en_ZA
dc.format.mediumPDFen_ZA
dc.identifier.citationOyewunmi, OA & Markides CN 2015, 'Effect of working-fluid mixtures on organic Rankine cycle system performance : heat transfer and cost analysis', Paper presented to the 11th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Florida, 20-23 July 2015.en_ZA
dc.identifier.isbn97817759206873
dc.identifier.urihttp://hdl.handle.net/2263/55917
dc.language.isoenen_ZA
dc.publisherInternational Conference on Heat Transfer, Fluid Mechanics and Thermodynamicsen_ZA
dc.rights© 2015 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria.en_ZA
dc.subjectOrganic Rankine cyclesen_ZA
dc.subjectWorking-fluid mixturesen_ZA
dc.subjectBenefitsen_ZA
dc.subjectThermodynamicen_ZA
dc.titleEffect of working-fluid mixtures on organic Rankine cycle system performance : heat transfer and cost analysisen_ZA
dc.typePresentationen_ZA

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