International Scientific Journal

Thermal Science - Online First

online first only

Theoretical and numerical analysis of the fixed flat-plate solar collector with Sn-Al2O3 selective absorber and gravity water flow

This paper presents two methods (theoretical and numerical) for the thermal analysis of the previously experimentally installed solar collector construction at the Faculty of Engineering in Kragujevac - a fixed flat-plate solar collector with Sn-Al2O3 selective absorber and gravity water flow. The theoretical research was based on the application of a specific calculation algorithm with a triple iterative procedure, i.e. with a three-stage check of all important performance indicators of the fixed flat-plate solar collector. In the numerical phase of the research, Simple Linear Regression was applied to experimentally measured values of solar radiation intensity and experimentally determine values of heat power to form simple equations that could be used to predict the thermal performance of similar solar structures in the future. The results of theoretical and numerical studies showed agreement with experimental studies, because in the first case, the absolute measurement error was less than 10%, while in the second case, the determination coefficient was greater than 90%, so the authors hope that this work will be useful to the wider scientific community.
PAPER REVISED: 2023-03-09
PAPER ACCEPTED: 2023-04-05
  1. Ibrahim, A., Kocak, S., Theoretical energy and exergy analyses of solar assisted heat pump space heating system, Thermal Science, 18 (2014), 2, pp. S417-S427, Doi: 10.2298/TSCI120813024A.
  2. Solanki, A., Yash, P., Applications of a flat plate collector in dairy industries: A review, International Journal of Ambient Energy, 43 (2022), 1, pp. 1915-1923, Doi: 10.1080/01430750.2020.1721326.
  3. Nešović, A., Theoretical model of solar incident angle for an optionally oriented fixed flat surface, Technique, 77 (2022), 3, pp. 328-333, Doi: 10.5937/tehnika2203328N.
  4. Wazwaz, A., et. al., Solar thermal performance of a nickel-pigmented aluminium oxide selective absorber, Renewable Energy, 27 (2002), 2, pp. 277-292, Doi: 10.1016/S0960-1481(01)00192-6.
  5. Wazwaz, A., et. al., The effects of nickel-pigmented aluminium oxide selective coating over aluminium alloy on the optical properties and thermal efficiency of the selective absorber prepared by alternate and reverse periodic plating technique, Energy Conversion and Management, 51 (2010), 8, pp. 1679-1683, Doi: 10.1016/j.enconman.2009.11.047.
  6. Li, Z., et. al., Aqueous solution-chemical derived Ni-Al2O3 solar selective absorbing coatings, Solar Energy Materials and Solar Cells, 105 (2012), No, pp. 90-95, Doi: 10.1016/j.solmat.2012.05.030.
  7. Xue, Y., et. al., Spectral properties and thermal stability of solar selective absorbing AlNi-Al2O3 cermet coating, Solar Energy, 96 (2013), No, pp. 113-118, Doi: 10.1016/j.solener.2013.07.012.
  8. Teixeira V., et. al., Spectrally selective composite coatings of Cr-Cr2O3 and Mo-Al2O3 for solar energy applications, Thin Solid Films, 392 (2001), 2, pp. 320-326, Doi: 10.1016/S0040-6090(01)01051-3.
  9. Xinkang, D., et. al., Microstructure and spectral selectivity of Mo-Al2O3 solar selective absorbing coatings after annealing, Thin Solid Films, 516 (2008), 12, pp. 3971-3977, Doi: 10.1016/j.tsf.2007.07.193.
  10. Antonaia, A., et. al., Stability of W-Al2O3 cermet based solar coating for receiver tube operating at high temperature, Solar Energy Materials and Solar Cells, 94 (2010), 10, pp. 1604-1611, Doi: 10.1016/j.solmat.2010.04.080.
  11. Ding, D., et. al., Optical, structural and thermal characteristics of Cu-CuAl2O4 hybrids deposited in anodic aluminum oxide as selective solar absorber, Solar Energy Materials and Solar Cells, 94 (2010), 10, pp. 1578-1581, Doi: 10.1016/j.solmat.2010.04.075.
  12. Nuru, Z. Y., et. al., Pt-Al2O3 nanocoatings for high temperature concentrated solar thermal power applications, Physica B: Condensed Matter, 407 (2012), 10, pp. 1634-1637, Doi: 10.1016/j.physb.2011.09.104.
  13. Barshilia, H. C., et. al., Structure and optical properties of Ag-Al2O3 nanocermet solar selective coatings prepared using unbalanced magnetron sputtering, Solar Energy Materials and Solar Cells, 95 (2011), 7, pp. 1707-1715, Doi: 10.1016/j.solmat.2011.01.034.
  14. Chorchong, T., et. al., Characterization and spectral selectivity of Sn-Al2O3 solar absorber, Key Engineering Materials, 675 (2016), No, pp. 467-472, Doi: 10.4028/
  15. Wamae, W., et. al., Influence of tin content on spectral selectivity and thermal conductivity of Sn-Al2O3 solar selective absorber, Materials for Renewable and Sustainable Energy, 7 (2018), No, pp. 1-8, Doi: 10.1007/s40243-017-0109-1.
  16. Wamae, W., et. al., Thermal efficiency of a new prototype of evacuated tube collector using Sn-Al2O3 as a selective solar absorber, Walailak Journal of Science and Technology, 15 (2018), 11, pp. 793-802, Doi: 10.48048/wjst.2018.5965.
  17. Alvarez, A., et. al., Experimental and numerical investigation of a flat-plate solar collector, Energy, 35 (2010), 9, pp. 3707-3716, Doi: 10.1016/
  18. Hellstrom, B., et. al., The impact of optical and thermal properties on the performance of flat plate solar collectors, Renewable Energy, 28 (2003), 3, pp. 331-344, Doi: 10.1016/S0960-1481(02)00040-X.
  19. Shemelin, V., Matuska, T., Detailed modeling of flat plate solar collector with vacuum glazing, International Journal of Photoenergy, No (2017), No, pp. 1-9, Doi: 10.1155/2017/1587592.
  20. Khoukhi, M., et. al., Flat-plate solar collector performance with coated and uncoated glass cover, Heat Transfer Engineering, 27 (2006), 1, pp. 46-53, Doi: 10.1080/01457630500343009.
  21. Akhtar, N., Mullick, S. C., Computation of glass-cover temperatures and top heat loss coefficient of flat-plate solar collectors with double glazing, Energy, 32 (2007), 7, pp. 1067-1074, Doi: 10.1016/
  22. Subiantoro, A., Ooi, K. T., Analytical models for the computation and optimization of single and double glazing flat plate solar collectors with normal and small air gap spacing, Applied Energy, 104 (2013), No, pp. 392-399, Doi: 10.1016/j.apenergy.2012.11.009.
  23. Chen, C. Q., et. al., Numerical evaluation of the thermal performance of different types of double glazing flat-plate solar air collectors, Energy, 233 (2021), No, pp. 121087, Doi: 10.1016/
  24. Vettrivel, H., Mathiazhagan, P., Comparison study of solar flat plate collector with single and double glazing systems, International Journal of Renewable Energy Research, 7 (2017), 1, pp. 266-274, Doi: 10.20508/ijrer.v7i1.5397.g6985.
  25. Baccoli, R., et. al., A mathematical model of a solar collector augmented by a flat plate above reflector: Optimum inclination of collector and reflector, Energy Procedia, 81 (2015), No, pp. 205-214, Doi: 10.1016/j.egypro.2015.12.085.
  26. Baccoli, R., et. al., A comprehensive optimization model for flat solar collector coupled with a flat booster bottom reflector based on an exact finite length simulation model, Energy Conversion and Management, 164 (2018), No, pp. 482-507, Doi: 10.1016/j.enconman.2018.02.091.
  27. Chiam, H. F., Planar concentrators for flat-plate solar collectors, Solar Energy, 26 (1981), 6, pp. 503-509, Doi: 10.1016/0038-092X(81)90161-4.
  28. Larson, D. C., Mirror enclosures for double-exposure solar collectors, Solar Energy, 23 (1979), 6, pp. 517-524, Doi: 10.1016/0038-092X(79)90076-8.
  29. Nikolić, N., Lukić, N., A mathematical model for determining the optimal reflector position of a double exposure flat-plate solar collector, Renewable Energy, 51 (2013), No, pp. 292-301, Doi: 10.1016/j.renene.2012.09.034.
  30. Maia, C. B., et. al., Evaluation of a tracking flat-plate solar collector in Brazil, Applied Thermal Engineering, 73 (2014), 1, pp. 953-962, Doi: 10.1016/j.applthermaleng.2014.08.052.
  31. Neville, R. C., Solar energy collector orientation and tracking mode, Solar Energy, 20 (1978), 1, pp. 7-11, Doi: 10.1016/0038-092X(78)90134-2.
  32. Drago, P., A simulated comparison of the useful energy gain in a fixed and a fully tracking flat plate collector, Proceedings of the International Symposium - Workshop on Solar Energy, Cairo, Egypt, 1980, Vol. No, pp. 258-273.
  33. Attalage, R. A., Agami, R. T., Annual collectible energy of a two-axis tracking flat-plate solar collector, Solar Energy, 48 (1992), 3, pp. 151-155, Doi: 10.1016/0038-092X(92)90133-U.
  34. Nešović, A., et. al., Experimental analysis of the fixed flat-plate solar collector with Sn-Al2O3 selective absorber and gravity water flow, Thermal Science, 27 (2023), 1A, pp. 349-358, Doi: 10.2298/TSCI220904171N.
  35. Beckman, W. A., et. al., Solar heating design, by the f-chart method, NASA STI/Recon Technical Report A, 78 (1977), No, pp. 31071, Doi: No.
  36. Mehregan, M., et. al., Energy, economic, environmental investigations and optimization of a combined cooling, heating and power system with hybrid prime mover of gas engine and flat plate solar collector, Energy Conversion and Management, 251 (2022), No, pp. 115018, Doi: 10.1016/j.enconman.2021.115018.
  37. Rabl, A., Active solar collectors and their applications, Oxford University Press on Demand, Oxford, UK, 1985.
  38. Kalogirou, S. A., Solar thermal collectors and applications, Progress in Energy and Combustion Science, 30 (2004), 3, pp. 231-295, Doi: 10.1016/j.pecs.2004.02.001.
  39. Stine, W. B., Harrigan, R. W., Solar energy fundamentals and design, Wiley-Interscience, New York, USA, 1985.
  40. Wang, D., et. al., Thermal performance analysis of large-scale flat plate solar collectors and regional applicability in China, Energy, 238 (2022), No, pp. 121931, Doi: 10.1016/
  41. Ali, S. H., et. al., Energetic and exegetic performance analysis of flat plate solar collector under variables heat transfer coefficient and inlet water temperature, Case Studies in Thermal Engineering, 28 (2021), No, pp. 101700, Doi: 10.1016/j.csite.2021.101700.
  42. Jurišević, N., System for monitoring and targeting of energy and water consumption in pubic buildings, Ph. D. thesis, University of Kragujevac, Kragujevac, SRB, 2021.