Performance and Exergy Transfer Analysis of Heat Exchangers with Graphene Nanofluids in Seawater Source Marine Heat Pump System
A marine seawater source heat pump is based on the relatively stable temperature of seawater, and uses it as the system’s cold and heat source to provide the ship with the necessary cold and heat energy. This technology is one of the important solutions to reduce ship energy consumption. Therefore,...
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MDPI AG
2020-04-01
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| Series: | Energies |
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| Online Access: | https://www.mdpi.com/1996-1073/13/7/1762 |
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| author | Zhe Wang Fenghui Han Yulong Ji Wenhua Li |
| author_facet | Zhe Wang Fenghui Han Yulong Ji Wenhua Li |
| author_sort | Zhe Wang |
| collection | DOAJ |
| description | A marine seawater source heat pump is based on the relatively stable temperature of seawater, and uses it as the system’s cold and heat source to provide the ship with the necessary cold and heat energy. This technology is one of the important solutions to reduce ship energy consumption. Therefore, in this paper, the heat exchanger in the CO<sub>2</sub> heat pump system with graphene nano-fluid refrigerant is experimentally studied, and the influence of related factors on its heat transfer enhancement performance is analyzed. First, the paper describes the transformation of the heat pump system experimental bench, the preparation of six different mass concentrations (0~1 wt.%) of graphene nanofluid and its thermophysical properties. Secondly, this paper defines graphene nanofluids as beneficiary fluids, the heat exchanger gains cold fluid heat exergy increase, and the consumption of hot fluid heat is heat exergy decrease. Based on the heat transfer efficiency and exergy efficiency of the heat exchanger, an exergy transfer model was established for a seawater source of tube heat exchanger. Finally, the article carried out a test of enhanced heat transfer of heat exchangers with different concentrations of graphene nanofluid refrigerants under simulated seawater constant temperature conditions and analyzed the test results using energy and an exergy transfer model. The results show that the enhanced heat transfer effect brought by the low concentration (0~0.1 wt.%) of graphene nanofluid is greater than the effect of its viscosity on the performance and has a good exergy transfer effectiveness. When the concentration of graphene nanofluid is too high, the resistance caused by the increase in viscosity will exceed the enhanced heat transfer gain brought by the nanofluid, which results in a significant decrease in the exergy transfer effectiveness. |
| first_indexed | 2024-03-10T20:37:43Z |
| format | Article |
| id | doaj.art-586b0bfc2962462ab6dedc4af33a7094 |
| institution | Directory Open Access Journal |
| issn | 1996-1073 |
| language | English |
| last_indexed | 2024-03-10T20:37:43Z |
| publishDate | 2020-04-01 |
| publisher | MDPI AG |
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| series | Energies |
| spelling | doaj.art-586b0bfc2962462ab6dedc4af33a70942023-11-19T20:51:51ZengMDPI AGEnergies1996-10732020-04-01137176210.3390/en13071762Performance and Exergy Transfer Analysis of Heat Exchangers with Graphene Nanofluids in Seawater Source Marine Heat Pump SystemZhe Wang0Fenghui Han1Yulong Ji2Wenhua Li3Marine Engineering College, Dalian Maritime University, Dalian 116026, ChinaMarine Engineering College, Dalian Maritime University, Dalian 116026, ChinaMarine Engineering College, Dalian Maritime University, Dalian 116026, ChinaMarine Engineering College, Dalian Maritime University, Dalian 116026, ChinaA marine seawater source heat pump is based on the relatively stable temperature of seawater, and uses it as the system’s cold and heat source to provide the ship with the necessary cold and heat energy. This technology is one of the important solutions to reduce ship energy consumption. Therefore, in this paper, the heat exchanger in the CO<sub>2</sub> heat pump system with graphene nano-fluid refrigerant is experimentally studied, and the influence of related factors on its heat transfer enhancement performance is analyzed. First, the paper describes the transformation of the heat pump system experimental bench, the preparation of six different mass concentrations (0~1 wt.%) of graphene nanofluid and its thermophysical properties. Secondly, this paper defines graphene nanofluids as beneficiary fluids, the heat exchanger gains cold fluid heat exergy increase, and the consumption of hot fluid heat is heat exergy decrease. Based on the heat transfer efficiency and exergy efficiency of the heat exchanger, an exergy transfer model was established for a seawater source of tube heat exchanger. Finally, the article carried out a test of enhanced heat transfer of heat exchangers with different concentrations of graphene nanofluid refrigerants under simulated seawater constant temperature conditions and analyzed the test results using energy and an exergy transfer model. The results show that the enhanced heat transfer effect brought by the low concentration (0~0.1 wt.%) of graphene nanofluid is greater than the effect of its viscosity on the performance and has a good exergy transfer effectiveness. When the concentration of graphene nanofluid is too high, the resistance caused by the increase in viscosity will exceed the enhanced heat transfer gain brought by the nanofluid, which results in a significant decrease in the exergy transfer effectiveness.https://www.mdpi.com/1996-1073/13/7/1762exergy transfer performancenanofluidsheat exchangermarine seawater sourceheat pumpgraphene nanoparticles |
| spellingShingle | Zhe Wang Fenghui Han Yulong Ji Wenhua Li Performance and Exergy Transfer Analysis of Heat Exchangers with Graphene Nanofluids in Seawater Source Marine Heat Pump System Energies exergy transfer performance nanofluids heat exchanger marine seawater source heat pump graphene nanoparticles |
| title | Performance and Exergy Transfer Analysis of Heat Exchangers with Graphene Nanofluids in Seawater Source Marine Heat Pump System |
| title_full | Performance and Exergy Transfer Analysis of Heat Exchangers with Graphene Nanofluids in Seawater Source Marine Heat Pump System |
| title_fullStr | Performance and Exergy Transfer Analysis of Heat Exchangers with Graphene Nanofluids in Seawater Source Marine Heat Pump System |
| title_full_unstemmed | Performance and Exergy Transfer Analysis of Heat Exchangers with Graphene Nanofluids in Seawater Source Marine Heat Pump System |
| title_short | Performance and Exergy Transfer Analysis of Heat Exchangers with Graphene Nanofluids in Seawater Source Marine Heat Pump System |
| title_sort | performance and exergy transfer analysis of heat exchangers with graphene nanofluids in seawater source marine heat pump system |
| topic | exergy transfer performance nanofluids heat exchanger marine seawater source heat pump graphene nanoparticles |
| url | https://www.mdpi.com/1996-1073/13/7/1762 |
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