{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,16]],"date-time":"2026-03-16T16:06:48Z","timestamp":1773677208392,"version":"3.50.1"},"reference-count":19,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2012,2,21]],"date-time":"2012-02-21T00:00:00Z","timestamp":1329782400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/3.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Entropy"],"abstract":"<jats:p>A numerical model of subcritical and trans-critical power cycles using a fixed-flowrate low-temperature heat source has been validated and used to calculate the combinations of the maximum cycle pressure (Pev) and the difference between the source temperature and the maximum working fluid temperature (DT) which maximize the thermal efficiency (\u03b7th) or minimize the non-dimensional exergy losses (\u03b2), the total thermal conductance of the heat exchangers (UAt) and the turbine size (SP). Optimum combinations of Pev and DT were calculated for each one of these four objective functions for two working fluids (R134a, R141b), three source temperatures and three values of the non-dimensional power output. The ratio of UAt over the net power output (which is a first approximation of the initial cost per kW) shows that R141b is the better working fluid for the conditions under study.<\/jats:p>","DOI":"10.3390\/e14020370","type":"journal-article","created":{"date-parts":[[2012,2,21]],"date-time":"2012-02-21T11:10:48Z","timestamp":1329822648000},"page":"370-389","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":38,"title":["Optimal Design of ORC Systems with a Low-Temperature Heat Source"],"prefix":"10.3390","volume":"14","author":[{"given":"Mohammed","family":"Khennich","sequence":"first","affiliation":[{"name":"Facult\u00e9 de G\u00e9nie, Universit\u00e9 de Sherbrooke, Sherbrooke QC, J1K 2R1, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Nicolas","family":"Galanis","sequence":"additional","affiliation":[{"name":"Facult\u00e9 de G\u00e9nie, Universit\u00e9 de Sherbrooke, Sherbrooke QC, J1K 2R1, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2012,2,21]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"565","DOI":"10.1016\/j.geothermics.2003.10.003","article-title":"Second law assessment of binary plants generating power from low-temperature geothermal fluids","volume":"33","author":"DiPippo","year":"2004","journal-title":"Geothermics"},{"key":"ref_2","first-page":"1","article-title":"Description and evaluation of the new 1,000 kWel organic Rankine cycle process integrated in the biomass CHP plant in Lienz, Austria","volume":"10","author":"Obernberger","year":"2002","journal-title":"Euroheat and Power"},{"key":"ref_3","unstructured":"Quoilin, S., and Lemort, V. (2009, January 14\u201317). Technological and economical survey of organic Rankine cycle systems. Proceedings of the 5th European Conference Economics and Management of Energy in Industry, Vilamoura, Algarve, Portugal."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1207","DOI":"10.1016\/j.energy.2004.01.004","article-title":"Effect of working fluids on organic Rankine cycle for waste heat recovery","volume":"29","author":"Liu","year":"2004","journal-title":"Energy"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1210","DOI":"10.1016\/j.energy.2006.07.001","article-title":"Working fluids for low-temperature organic Rankine cycles","volume":"32","author":"Saleh","year":"2007","journal-title":"Energy"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1262","DOI":"10.1016\/j.applthermaleng.2010.02.009","article-title":"Working fluids for low-temperature heat source","volume":"30","author":"Lakew","year":"2010","journal-title":"Appl. Therm. Eng."},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Khennich, M., and Galanis, N. (2011). Thermodynamic analysis and optimization of power cycles using a finite low-temperature heat source. Int. J. Energy Res.","DOI":"10.1002\/er.1839"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"136","DOI":"10.1016\/j.energy.2011.12.022","article-title":"The optimal evaporation temperature and working fluids for subcritical organic Rankine cycle","volume":"38","author":"He","year":"2012","journal-title":"Energy"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1349","DOI":"10.1016\/j.apenergy.2009.08.031","article-title":"Parametric study and optimization of a transcritical power cycle using a low temperature source","volume":"87","author":"Cayer","year":"2010","journal-title":"Appl. Energy"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"718","DOI":"10.1115\/1.3230794","article-title":"Efficiency prediction for axial-flow turbines operating with non conventional fluids","volume":"103","author":"Macchi","year":"1981","journal-title":"J. Eng. Power Trans. ASME"},{"key":"ref_11","unstructured":"EES Engineering equation solver. Available online: http:\/\/www.mhhe.com\/engcs\/mech\/ees\/whatisees.html."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1698","DOI":"10.1016\/j.energy.2007.01.005","article-title":"Optimum design criteria for an organic Rankine cycle using low-temperature geothermal heat sources","volume":"32","author":"Golubovic","year":"2007","journal-title":"Energy"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"3059","DOI":"10.1016\/j.rser.2010.07.006","article-title":"A review of thermodynamic cycles and working fluids for the conversion of low-grade heat","volume":"14","author":"Chen","year":"2010","journal-title":"Renew. Sus. Energy Rev."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1033","DOI":"10.1016\/j.energy.2009.06.019","article-title":"Efficiency optimization potential in supercritical organic Rankine cycles","volume":"35","author":"Schuster","year":"2010","journal-title":"Energy"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"2639","DOI":"10.1016\/j.energy.2011.02.005","article-title":"Fluids and parameters optimization for a novel cogeneration system driven by low-temperature geothermal sources","volume":"36","author":"Guo","year":"2011","journal-title":"Energy"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"3406","DOI":"10.1016\/j.energy.2011.03.041","article-title":"Study of working fluid selection of organic Rankine cycle (ORC) for engine waste recovery","volume":"36","author":"Wang","year":"2011","journal-title":"Energy"},{"key":"ref_17","first-page":"657","article-title":"An international standard formulation of the thermodynamic properties of 1,1,1,2-tetrafluoroethane (HFC-134a) covering temperatures from 170 K to 455 K at pressures up to 70 MPa","volume":"23","author":"Baehr","year":"1994","journal-title":"J. Phys. Chem. Ref."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"142","DOI":"10.1002\/aic.690010203","article-title":"Development of an equation of state for gases","volume":"1","author":"Martin","year":"1955","journal-title":"AIChE J."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1055","DOI":"10.1016\/j.apenergy.2008.09.018","article-title":"Analysis of a carbon dioxide transcritical power cycle using a low temperature source","volume":"86","author":"Cayer","year":"2009","journal-title":"Appl. Energy"}],"container-title":["Entropy"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1099-4300\/14\/2\/370\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T21:49:00Z","timestamp":1760219340000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1099-4300\/14\/2\/370"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2012,2,21]]},"references-count":19,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2012,2]]}},"alternative-id":["e14020370"],"URL":"https:\/\/doi.org\/10.3390\/e14020370","relation":{},"ISSN":["1099-4300"],"issn-type":[{"value":"1099-4300","type":"electronic"}],"subject":[],"published":{"date-parts":[[2012,2,21]]}}}