An Improved Modelling Approach for the Comprehensive Study of Direct Contact Membrane Distillation
Direct Contact Membrane Distillation (DCMD) is a promising and feasible technology for water desalination. Most of the models used to simulate DCMD are one-dimensional and/or use a linear function of vapour pressure which relies on experimentally determined parameters. In this study, the model of DC...
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-04-01
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| Series: | Membranes |
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| Online Access: | https://www.mdpi.com/2077-0375/11/5/308 |
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| author | Abolfazl Ansari Saman Kavousi Fernanda Helfer Graeme Millar David V. Thiel |
| author_facet | Abolfazl Ansari Saman Kavousi Fernanda Helfer Graeme Millar David V. Thiel |
| author_sort | Abolfazl Ansari |
| collection | DOAJ |
| description | Direct Contact Membrane Distillation (DCMD) is a promising and feasible technology for water desalination. Most of the models used to simulate DCMD are one-dimensional and/or use a linear function of vapour pressure which relies on experimentally determined parameters. In this study, the model of DCMD using Nusselt correlations was improved by coupling the continuity, momentum, and energy equations to better capture the downstream alteration of flow field properties. A logarithmic function of vapour pressure, which is independent from experiments, was used. This allowed us to analyse DCMD with different membrane properties. The results of our developed model were in good agreement with the DCMD experimental results, with less than 7% deviation. System performance metrics, including water flux, temperature, and concentration polarisation coefficient and thermal efficiency, were analysed by varying inlet feed and permeate temperature, inlet velocity, inlet feed concentration, channel length. In addition, twenty-two commercial membranes were analysed to obtain a real vision on the influence of membrane characteristics on system performance metrics. The results showed that the feed temperature had the most significant effect on water flux and thermal efficiency. The increased feed temperature enhanced the water flux and thermal efficiency; however, it caused more concentration and temperature polarisation. On the other hand, the increased inlet velocity was found to provide increased water flux and reduced temperature and concertation polarisation as well. It was also found that the membrane properties, especially thickness and porosity, can affect the DCMD performance significantly. A two-fold increase of feed temperature increased the water flux and thermal efficiency, 10-fold and 27%, respectively; however, it caused an increase in temperature and concertation polarisation, at 48% and 34%, respectively. By increasing Reynolds number from 80 to 1600, the water flux, CPC, and TPC enhanced by 2.3-fold, 2%, and 21%, respectively. The increased feed concentration from 0 to 250 [g/L] caused a 26% reduction in water flux. To capture the downstream alteration of flow properties, it was shown that the ratio of inlet value to outlet value of system performance metrics decreased significantly throughout the module. Therefore, improvement over the conventional model is undeniable, as the new model can assist in achieving optimal operation conditions. |
| first_indexed | 2024-03-10T12:03:46Z |
| format | Article |
| id | doaj.art-649a1c0d199046ee85c94dea1d41fc9b |
| institution | Directory Open Access Journal |
| issn | 2077-0375 |
| language | English |
| last_indexed | 2024-03-10T12:03:46Z |
| publishDate | 2021-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Membranes |
| spelling | doaj.art-649a1c0d199046ee85c94dea1d41fc9b2023-11-21T16:44:36ZengMDPI AGMembranes2077-03752021-04-0111530810.3390/membranes11050308An Improved Modelling Approach for the Comprehensive Study of Direct Contact Membrane DistillationAbolfazl Ansari0Saman Kavousi1Fernanda Helfer2Graeme Millar3David V. Thiel4School of Engineering and Built Environment, Griffith University, Brisbane, QLD 4111, AustraliaIndependent Researcher, Esteghlal Blvd., Shiraz 71757-43659, IranSchool of Engineering and Built Environment, Griffith University, Brisbane, QLD 4111, AustraliaInstitute for Future Environments, School of Mechanical, Medical & Process Engineering, Science and Engineering Faculty, Queensland University of Technology (QUT), Brisbane, QLD 4000, AustraliaSchool of Engineering and Built Environment, Griffith University, Brisbane, QLD 4111, AustraliaDirect Contact Membrane Distillation (DCMD) is a promising and feasible technology for water desalination. Most of the models used to simulate DCMD are one-dimensional and/or use a linear function of vapour pressure which relies on experimentally determined parameters. In this study, the model of DCMD using Nusselt correlations was improved by coupling the continuity, momentum, and energy equations to better capture the downstream alteration of flow field properties. A logarithmic function of vapour pressure, which is independent from experiments, was used. This allowed us to analyse DCMD with different membrane properties. The results of our developed model were in good agreement with the DCMD experimental results, with less than 7% deviation. System performance metrics, including water flux, temperature, and concentration polarisation coefficient and thermal efficiency, were analysed by varying inlet feed and permeate temperature, inlet velocity, inlet feed concentration, channel length. In addition, twenty-two commercial membranes were analysed to obtain a real vision on the influence of membrane characteristics on system performance metrics. The results showed that the feed temperature had the most significant effect on water flux and thermal efficiency. The increased feed temperature enhanced the water flux and thermal efficiency; however, it caused more concentration and temperature polarisation. On the other hand, the increased inlet velocity was found to provide increased water flux and reduced temperature and concertation polarisation as well. It was also found that the membrane properties, especially thickness and porosity, can affect the DCMD performance significantly. A two-fold increase of feed temperature increased the water flux and thermal efficiency, 10-fold and 27%, respectively; however, it caused an increase in temperature and concertation polarisation, at 48% and 34%, respectively. By increasing Reynolds number from 80 to 1600, the water flux, CPC, and TPC enhanced by 2.3-fold, 2%, and 21%, respectively. The increased feed concentration from 0 to 250 [g/L] caused a 26% reduction in water flux. To capture the downstream alteration of flow properties, it was shown that the ratio of inlet value to outlet value of system performance metrics decreased significantly throughout the module. Therefore, improvement over the conventional model is undeniable, as the new model can assist in achieving optimal operation conditions.https://www.mdpi.com/2077-0375/11/5/308desalinationmembrane distillationmodellingtemperature and concentration polarisation |
| spellingShingle | Abolfazl Ansari Saman Kavousi Fernanda Helfer Graeme Millar David V. Thiel An Improved Modelling Approach for the Comprehensive Study of Direct Contact Membrane Distillation Membranes desalination membrane distillation modelling temperature and concentration polarisation |
| title | An Improved Modelling Approach for the Comprehensive Study of Direct Contact Membrane Distillation |
| title_full | An Improved Modelling Approach for the Comprehensive Study of Direct Contact Membrane Distillation |
| title_fullStr | An Improved Modelling Approach for the Comprehensive Study of Direct Contact Membrane Distillation |
| title_full_unstemmed | An Improved Modelling Approach for the Comprehensive Study of Direct Contact Membrane Distillation |
| title_short | An Improved Modelling Approach for the Comprehensive Study of Direct Contact Membrane Distillation |
| title_sort | improved modelling approach for the comprehensive study of direct contact membrane distillation |
| topic | desalination membrane distillation modelling temperature and concentration polarisation |
| url | https://www.mdpi.com/2077-0375/11/5/308 |
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