Performance Analysis of a RED-MED Salinity Gradient Heat Engine
A performance analysis of a salinity gradient heat engine (SGP-HE) is presented for the conversion of low temperature heat into power via a closed-loop Reverse Electrodialysis (RED) coupled with Multi-Effect Distillation (MED). Mathematical models for the RED and MED systems have been purposely deve...
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| Format: | Article |
| Language: | English |
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MDPI AG
2018-12-01
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| Series: | Energies |
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| Online Access: | https://www.mdpi.com/1996-1073/11/12/3385 |
| _version_ | 1818038039891410944 |
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| author | Patricia Palenzuela Marina Micari Bartolomé Ortega-Delgado Francesco Giacalone Guillermo Zaragoza Diego-César Alarcón-Padilla Andrea Cipollina Alessandro Tamburini Giorgio Micale |
| author_facet | Patricia Palenzuela Marina Micari Bartolomé Ortega-Delgado Francesco Giacalone Guillermo Zaragoza Diego-César Alarcón-Padilla Andrea Cipollina Alessandro Tamburini Giorgio Micale |
| author_sort | Patricia Palenzuela |
| collection | DOAJ |
| description | A performance analysis of a salinity gradient heat engine (SGP-HE) is presented for the conversion of low temperature heat into power via a closed-loop Reverse Electrodialysis (RED) coupled with Multi-Effect Distillation (MED). Mathematical models for the RED and MED systems have been purposely developed in order to investigate the performance of both processes and have been then coupled to analyze the efficiency of the overall integrated system. The influence of the main operating conditions (i.e., solutions concentration and velocity) has been quantified, looking at the power density and conversion efficiency of the RED unit, MED Specific Thermal Consumption (STC) and at the overall system exergy efficiency. Results show how the membrane properties (i.e., electrical resistance, permselectivity, water and salt permeability) dramatically affect the performance of the RED process. In particular, the power density achievable using membranes with optimized features (ideal membranes) can be more than three times higher than that obtained with current reference ion exchange membranes. On the other hand, MED STC is strongly influenced by the available waste heat temperature, feed salinity and recovery ratio to be achieved. Lowest values of STC below 25 kWh/m<sup>3</sup> can be reached at 100 °C and 27 effects. Increasing the feed salinity also increases the STC, while an increase in the recovery ratio is beneficial for the thermal efficiency of the system. For the integrated system, a more complex influence of operating parameters has been found, leading to the identification of some favorable operating conditions in which exergy efficiency close to 7% (1.4% thermal) can be achieved for the case of current membranes, and up to almost 31% (6.6% thermal) assuming ideal membrane properties. |
| first_indexed | 2024-12-10T07:36:24Z |
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| id | doaj.art-87d025d1662541ad9c89667670f47dac |
| institution | Directory Open Access Journal |
| issn | 1996-1073 |
| language | English |
| last_indexed | 2024-12-10T07:36:24Z |
| publishDate | 2018-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Energies |
| spelling | doaj.art-87d025d1662541ad9c89667670f47dac2022-12-22T01:57:25ZengMDPI AGEnergies1996-10732018-12-011112338510.3390/en11123385en11123385Performance Analysis of a RED-MED Salinity Gradient Heat EnginePatricia Palenzuela0Marina Micari1Bartolomé Ortega-Delgado2Francesco Giacalone3Guillermo Zaragoza4Diego-César Alarcón-Padilla5Andrea Cipollina6Alessandro Tamburini7Giorgio Micale8CIEMAT-Plataforma Solar de Almería, Ctra. de Senés s/n, 04200 Tabernas, Almería, SpainDIID—Dipartimento dell’Innovazione Industriale e Digitale—Ingegneria Chimica, Gestionale, Informatica, Meccanica, Università degli Studi di Palermo (UNIPA), viale delle Scienze, Ed. 6, 90128 Palermo, ItalyDIID—Dipartimento dell’Innovazione Industriale e Digitale—Ingegneria Chimica, Gestionale, Informatica, Meccanica, Università degli Studi di Palermo (UNIPA), viale delle Scienze, Ed. 6, 90128 Palermo, ItalyDIID—Dipartimento dell’Innovazione Industriale e Digitale—Ingegneria Chimica, Gestionale, Informatica, Meccanica, Università degli Studi di Palermo (UNIPA), viale delle Scienze, Ed. 6, 90128 Palermo, ItalyCIEMAT-Plataforma Solar de Almería, Ctra. de Senés s/n, 04200 Tabernas, Almería, SpainCIEMAT-Plataforma Solar de Almería, Ctra. de Senés s/n, 04200 Tabernas, Almería, SpainDIID—Dipartimento dell’Innovazione Industriale e Digitale—Ingegneria Chimica, Gestionale, Informatica, Meccanica, Università degli Studi di Palermo (UNIPA), viale delle Scienze, Ed. 6, 90128 Palermo, ItalyDIID—Dipartimento dell’Innovazione Industriale e Digitale—Ingegneria Chimica, Gestionale, Informatica, Meccanica, Università degli Studi di Palermo (UNIPA), viale delle Scienze, Ed. 6, 90128 Palermo, ItalyDIID—Dipartimento dell’Innovazione Industriale e Digitale—Ingegneria Chimica, Gestionale, Informatica, Meccanica, Università degli Studi di Palermo (UNIPA), viale delle Scienze, Ed. 6, 90128 Palermo, ItalyA performance analysis of a salinity gradient heat engine (SGP-HE) is presented for the conversion of low temperature heat into power via a closed-loop Reverse Electrodialysis (RED) coupled with Multi-Effect Distillation (MED). Mathematical models for the RED and MED systems have been purposely developed in order to investigate the performance of both processes and have been then coupled to analyze the efficiency of the overall integrated system. The influence of the main operating conditions (i.e., solutions concentration and velocity) has been quantified, looking at the power density and conversion efficiency of the RED unit, MED Specific Thermal Consumption (STC) and at the overall system exergy efficiency. Results show how the membrane properties (i.e., electrical resistance, permselectivity, water and salt permeability) dramatically affect the performance of the RED process. In particular, the power density achievable using membranes with optimized features (ideal membranes) can be more than three times higher than that obtained with current reference ion exchange membranes. On the other hand, MED STC is strongly influenced by the available waste heat temperature, feed salinity and recovery ratio to be achieved. Lowest values of STC below 25 kWh/m<sup>3</sup> can be reached at 100 °C and 27 effects. Increasing the feed salinity also increases the STC, while an increase in the recovery ratio is beneficial for the thermal efficiency of the system. For the integrated system, a more complex influence of operating parameters has been found, leading to the identification of some favorable operating conditions in which exergy efficiency close to 7% (1.4% thermal) can be achieved for the case of current membranes, and up to almost 31% (6.6% thermal) assuming ideal membrane properties.https://www.mdpi.com/1996-1073/11/12/3385salinity gradient energyexergyartificial solutionsmodelingheat engineRED-HE |
| spellingShingle | Patricia Palenzuela Marina Micari Bartolomé Ortega-Delgado Francesco Giacalone Guillermo Zaragoza Diego-César Alarcón-Padilla Andrea Cipollina Alessandro Tamburini Giorgio Micale Performance Analysis of a RED-MED Salinity Gradient Heat Engine Energies salinity gradient energy exergy artificial solutions modeling heat engine RED-HE |
| title | Performance Analysis of a RED-MED Salinity Gradient Heat Engine |
| title_full | Performance Analysis of a RED-MED Salinity Gradient Heat Engine |
| title_fullStr | Performance Analysis of a RED-MED Salinity Gradient Heat Engine |
| title_full_unstemmed | Performance Analysis of a RED-MED Salinity Gradient Heat Engine |
| title_short | Performance Analysis of a RED-MED Salinity Gradient Heat Engine |
| title_sort | performance analysis of a red med salinity gradient heat engine |
| topic | salinity gradient energy exergy artificial solutions modeling heat engine RED-HE |
| url | https://www.mdpi.com/1996-1073/11/12/3385 |
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