Using Graphene Nanoplatelets Nanofluid in a Closed-Loop Evacuated Tube Solar Collector—Energy and Exergy Analysis
| Autor: | Hwai C. Ong, Alireza Esmaeilzadeh, Soudeh Iranmanesh, Bee Chin Ang, M.S. Naghavi, Mahyar Silakhori |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Exergy
exergy Technology Materials science business.industry Science graphene nanoplatelets Thermodynamics Bejan number Volumetric flow rate thermal energy Entropy (classical thermodynamics) Nanofluid Thermal Ceramics and Composites Particle nanofluid business entropy Engineering (miscellaneous) Thermal energy |
| Zdroj: | Journal of Composites Science, Vol 5, Iss 277, p 277 (2021) Journal of Composites Science Volume 5 Issue 10 |
| Popis: | Recently, nanofluid application as a heat transfer fluid for a closed-loop solar heat collector is receiving great attention among the scientific community due to better performance. The performance of solar systems can be assessed effectively with the exergy method. The present study deals with the thermodynamic performance of the second law analysis using graphene nanoplatelets nanofluids. Second law analysis is the main tool for explaining the exergy output of thermodynamic and energy systems. The performance of the closed-loop system in terms of energy and exergy was determined by analyzing the outcome of field tests in tropical weather conditions. Moreover, three parameters of entropy generation, pumping power and Bejan number were also determined. The flowrates of 0.5, 1 and 1.5 L/min and GNP mass percentage of 0.025, 0.5, 0.075 and 0.1 wt% were used for these tests. The results showed that in a flow rate of 1.5 L/min and a concentration of 0.1 wt%, exergy and thermal efficiencies were increased to about 85.5 and 90.7%, respectively. It also found that entropy generation reduced when increasing the nanofluid concentration. The Bejan number surges up when increasing the concentration, while this number decreases with the enhancement of the volumetric flow rate. The pumping power of the nanofluid-operated system for a 0.1 wt% particle concentration at 0.5 L/min indicated 5.8% more than when pure water was used as the heat transfer fluid. Finally, this investigation reveals the perfect conditions that operate closest to the reversible limit and helps the system make the best improvement. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|