Thermoeconomic Analysis of Organic Rankine Cycle Using Zeotropic Mixtures

Muhammad Imran, Muhammad Usman, Dong Hyun Lee, Byung Sik Park

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

The selection of the working fluid is an important part of design and optimization of ORC system as it effects the systems efficiency, design of ORC components, stability, safety and environmental impact. Present study aims to investigate the performance of ORC system using pure working fluids and zeotropic mixtures for low temperature geothermal heat source on the basis of thermodynamic and economic parameters of ORC system. Evaporator, expander, condenser and feed pump models are developed in MATLAB. The control volume approach is adopted for evaporator and condenser model with appropriate database of heat transfer and pressure drop correlations. For comparison, pure working fluids are taken as the base case. The ORC system with pure working fluid and zeotropic mixture under same heat and sink source conditions are optimized using multi objective genetic algorithm for maximum exergy efficiency and minimum specific investment cost. The exergy efficiency of ORC system with zeotropic mixture is improved by 14.33% compared to pure working fluid. The exergy destruction in evaporator and condenser is reduced by 24~30%. The fraction of more volatile component in zeotropic mixture effected the thermal and economic performance of ORC system, for current study the mass fraction of 40% of R245fa corresponds to optimum exergy efficiency and specific investment cost. For same condensing pressure and expander power, area of evaporator for pure working fluids and zeotropic mixture is also calculated. The required heat transfer area for zeotropic mixture is approximately 13% less than required for pure working fluid.
Original languageEnglish
Title of host publicationProceedings of the 3rd International Seminar on ORC Power Systems
Number of pages11
Publication statusPublished - 2015
Event3rd International Seminar on ORC Power Systems - Brussels, Belgium
Duration: 12 Oct 201514 Oct 2015

Conference

Conference3rd International Seminar on ORC Power Systems
CountryBelgium
CityBrussels
Period12/10/1514/10/15

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Bibliographical note

© 2015 The Authors

Cite this

Imran, M., Usman, M., Lee, D. H., & Park, B. S. (2015). Thermoeconomic Analysis of Organic Rankine Cycle Using Zeotropic Mixtures. In Proceedings of the 3rd International Seminar on ORC Power Systems [161]