Subcritical Thermodynamic Cycles with Organic Medium and Isothermal Expansion
The efficiencies of the Organic Rankine Cycle (ORC) are not very high and only very seldom do they exceed 20%. The increase and optimization of initial parameters and certain modifications of the thermodynamic cycle make it possible to overcome these drawbacks. A new modified cycle has been describe...
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MDPI AG
2020-08-01
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| Series: | Energies |
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| Online Access: | https://www.mdpi.com/1996-1073/13/17/4340 |
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| author | Krzysztof Kosowski Marian Piwowarski |
| author_facet | Krzysztof Kosowski Marian Piwowarski |
| author_sort | Krzysztof Kosowski |
| collection | DOAJ |
| description | The efficiencies of the Organic Rankine Cycle (ORC) are not very high and only very seldom do they exceed 20%. The increase and optimization of initial parameters and certain modifications of the thermodynamic cycle make it possible to overcome these drawbacks. A new modified cycle has been described and analyzed in detail in the paper. Similarly to the Ericsson cycle for gas turbines, isothermal expansion in the turbine is suggested for the power plant with organic media. The new cycle and the typical ORC power plants have the same block diagram. The only difference is that expansion in the proposed cycle occurs not adiabatically but as an isothermal process. The thermodynamic calculations have been carried out for 11 various fluids and 4 different cycles. The obtained results have clearly shown that cycles with isothermal expansion (isothermal turbines) are characterized by remarkably higher efficiency than typical power plants with adiabatic turbines. The increase in efficiency varies from 6 to 12 percent points for cycles with saturated live vapor and from 4 to 7 percent points for cycles with superheated live vapor. The performed analyses have shown that it is possible to achieve a very high efficiency (over 45%) of organic cycle, which is a very competitive value. In such cases the proposed power plants can achieve an efficiency which is higher than that of modern steam turbine plants with supercritical parameters. |
| first_indexed | 2024-03-10T17:00:40Z |
| format | Article |
| id | doaj.art-358cd6609cbe4d52bfcc5dc3b530ca76 |
| institution | Directory Open Access Journal |
| issn | 1996-1073 |
| language | English |
| last_indexed | 2024-03-10T17:00:40Z |
| publishDate | 2020-08-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Energies |
| spelling | doaj.art-358cd6609cbe4d52bfcc5dc3b530ca762023-11-20T10:58:23ZengMDPI AGEnergies1996-10732020-08-011317434010.3390/en13174340Subcritical Thermodynamic Cycles with Organic Medium and Isothermal ExpansionKrzysztof Kosowski0Marian Piwowarski1Faculty of Mechanical Engineering, Gdansk University of Technology, Gabriela Narutowicza Street 11/12, 80-233 Gdansk, PolandFaculty of Mechanical Engineering, Gdansk University of Technology, Gabriela Narutowicza Street 11/12, 80-233 Gdansk, PolandThe efficiencies of the Organic Rankine Cycle (ORC) are not very high and only very seldom do they exceed 20%. The increase and optimization of initial parameters and certain modifications of the thermodynamic cycle make it possible to overcome these drawbacks. A new modified cycle has been described and analyzed in detail in the paper. Similarly to the Ericsson cycle for gas turbines, isothermal expansion in the turbine is suggested for the power plant with organic media. The new cycle and the typical ORC power plants have the same block diagram. The only difference is that expansion in the proposed cycle occurs not adiabatically but as an isothermal process. The thermodynamic calculations have been carried out for 11 various fluids and 4 different cycles. The obtained results have clearly shown that cycles with isothermal expansion (isothermal turbines) are characterized by remarkably higher efficiency than typical power plants with adiabatic turbines. The increase in efficiency varies from 6 to 12 percent points for cycles with saturated live vapor and from 4 to 7 percent points for cycles with superheated live vapor. The performed analyses have shown that it is possible to achieve a very high efficiency (over 45%) of organic cycle, which is a very competitive value. In such cases the proposed power plants can achieve an efficiency which is higher than that of modern steam turbine plants with supercritical parameters.https://www.mdpi.com/1996-1073/13/17/4340subcritical thermodynamic cyclesorganic mediaefficiencyisothermal expansionadiabatic expansion |
| spellingShingle | Krzysztof Kosowski Marian Piwowarski Subcritical Thermodynamic Cycles with Organic Medium and Isothermal Expansion Energies subcritical thermodynamic cycles organic media efficiency isothermal expansion adiabatic expansion |
| title | Subcritical Thermodynamic Cycles with Organic Medium and Isothermal Expansion |
| title_full | Subcritical Thermodynamic Cycles with Organic Medium and Isothermal Expansion |
| title_fullStr | Subcritical Thermodynamic Cycles with Organic Medium and Isothermal Expansion |
| title_full_unstemmed | Subcritical Thermodynamic Cycles with Organic Medium and Isothermal Expansion |
| title_short | Subcritical Thermodynamic Cycles with Organic Medium and Isothermal Expansion |
| title_sort | subcritical thermodynamic cycles with organic medium and isothermal expansion |
| topic | subcritical thermodynamic cycles organic media efficiency isothermal expansion adiabatic expansion |
| url | https://www.mdpi.com/1996-1073/13/17/4340 |
| work_keys_str_mv | AT krzysztofkosowski subcriticalthermodynamiccycleswithorganicmediumandisothermalexpansion AT marianpiwowarski subcriticalthermodynamiccycleswithorganicmediumandisothermalexpansion |