Combined non-gray radiative and conductive heat transfer in solar collector glass cover

Solar Energy ◽  
2003 ◽  
Vol 75 (4) ◽  
pp. 285-293 ◽  
Author(s):  
Maatouk Khoukhi ◽  
Shigenao Maruyama ◽  
Seigo Sakai ◽  
Masud Behnia
2021 ◽  
Vol 7 ◽  
Author(s):  
Muhammad Zain ◽  
Muhammad Amjad ◽  
Muhammad Farooq ◽  
Zahid Anwar ◽  
Rabia Shoukat ◽  
...  

The convective and conductive heat transfer between the solar collector and working fluids make photothermal performance limited, and result in a higher rate of heat loss from the surface of the conventional absorber to the surroundings. Direct absorption solar collectors (DASC) are a favorable alternative for their improved photothermal performance. In this study, a simulation based on the performance of a nanostructured solar collector has been carried out using TRNSYS. The connective and conductive heat transfer from direct solar collectors were improved by using nanofluids and three different nanostructured materials, CuO, GO, and ZnO, in this study. The analysis determines the outlet temperature of the working fluids that passed through the direct solar collector. The TRNSYS model consists of a direct solar collector and weather model for Lahore city, the simulations were performed for the whole year for 1,440 h. The stability of these nanostructured materials in the water was investigated by using a UV‐Vis spectrophotometer. Various performance parameters of direct solar collectors were determined, such as variation in outlet collector temperature and heat transfer rates. The numerical model is validated with experimental results. A maximum outlet temperature of 63°C was observed for GO-based nanofluids. The simulation results show that for the whole year, nanofluids improved the performance of direct solar collectors. Significant improvements in the heat transfer rate of 23.52, 21.11, and 15.09% were observed for the nanofluids based on nanostructures of CuO, ZnO, and GO respectively, as compared to water. These nanostructured energy materials are beneficial in solar-driven applications like solar desalination, solar water, and space heating.


2016 ◽  
Vol 289 ◽  
pp. 371-380 ◽  
Author(s):  
Alexander Yu. Chebotarev ◽  
Andrey E. Kovtanyuk ◽  
Gleb V. Grenkin ◽  
Nikolai D. Botkin ◽  
Karl-Heinz Hoffmann

1984 ◽  
Vol 106 (3) ◽  
pp. 613-619 ◽  
Author(s):  
M. M. Razzaque ◽  
J. R. Howell ◽  
D. E. Klein

A numerical solution of the exact equations of coupled radiative/conductive heat transfer and temperature distribution inside a medium, and of the heat flux distribution at all the gray walls of a two-dimensional rectangular enclosure with the medium having uniform absorbing/emitting properties, using the finite element method, is presented. The medium can also have distributed energy sources. Comparison is made to the results of the P-3 approximation method.


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