Imperial College London

ProfessorChristosMarkides

Faculty of EngineeringDepartment of Chemical Engineering

Professor of Clean Energy Technologies
 
 
 
//

Contact

 

+44 (0)20 7594 1601c.markides Website

 
 
//

Location

 

404ACE ExtensionSouth Kensington Campus

//

Summary

 

Publications

Citation

BibTex format

@article{Oyewunmi:2016:10.3390/en9060448,
author = {Oyewunmi, OA and Markides, C},
doi = {10.3390/en9060448},
journal = {Energies},
title = {Thermo-Economic and Heat Transfer Optimization of Working-Fluid Mixtures in a Low-Temperature Organic Rankine Cycle System},
url = {http://dx.doi.org/10.3390/en9060448},
volume = {9},
year = {2016}
}

RIS format (EndNote, RefMan)

TY  - JOUR
AB - In the present paper, we consider the employment of working-fluid mixtures in organicRankine cycle (ORC) systems with respect to thermodynamic and heat-transfer performance,component sizing and capital costs. The selected working-fluid mixtures promise reduced exergylosses due to their non-isothermal phase-change behaviour, and thus improved cycle efficienciesand power outputs over their respective pure-fluid components. A multi-objective cost-poweroptimization of a specific low-temperature ORC system (operating with geothermal water at 98 C)reveals that the use of working-fluid-mixtures does indeed show a thermodynamic improvementover the pure-fluids. At the same time, heat transfer and cost analyses, however, suggest that it alsorequires larger evaporators, condensers and expanders; thus, the resulting ORC systems are alsoassociated with higher costs. In particular, 50% n-pentane + 50% n-hexane and 60% R-245fa + 40%R-227ea mixtures lead to the thermodynamically optimal cycles, whereas pure n-pentane and pureR-245fa have lower plant costs, both estimated as having ∼14% lower costs per unit power outputcompared to the thermodynamically optimal mixtures. These conclusions highlight the importanceof using system cost minimization as a design objective for ORC plants.
AU - Oyewunmi,OA
AU - Markides,C
DO - 10.3390/en9060448
PY - 2016///
SN - 1996-1073
TI - Thermo-Economic and Heat Transfer Optimization of Working-Fluid Mixtures in a Low-Temperature Organic Rankine Cycle System
T2 - Energies
UR - http://dx.doi.org/10.3390/en9060448
UR - http://hdl.handle.net/10044/1/33175
VL - 9
ER -