Substantiation of parameters and operational modes of air solar collector

Authors

DOI:

https://doi.org/10.15587/1729-4061.2018.132090

Keywords:

air solar collector, transparent coating, temperature field, heat flow, heat exchange, heat loss

Abstract

We developed a new design of an air solar collector for a fruit dryer including double glazing and a selective surface made of a thin metal substrate with inlet and outlet openings on its bottom. We established that it is necessary to use a glass with a heat-reflecting coating of a solid K-glass type with a radiation coefficient ε=0.1...0.15 for a double-glazing substrate. This makes it possible to obtain the widest possible spectrum of direct sunlight rays that irradiate a surface of an absorbing plate and reduces a diffuse component of radiation, which ensures an increase in efficiency of a solar collector.

We determined regularities of the influence of a change in flow speed of a heat-transfer agent, a temperature drop, and radiation intensity on power of a solar collector. We developed a model of heat exchange processes occurring in an air solar collector. We presented the methodology for estimation of heat loss of an air solar collector with passive use of solar energy.

We established that energy illumination E, which is from 377 to 1,223 W/m2, affects heat output of an air collector Q=117...480 W significantly. We established that a use of a non-selective absorbing surface in an air solar collector with a low insolation level E=377 W/m2 makes it possible to increase efficiency by η=70.7 % more for selective, and at a large energy illumination of E=1,000 W/m2, on the contrary small η=54.6 %. This makes it possible to explain how redistribution of the ratio of the maximum current thermal power (NSC=48.8...100 W) and efficiency of an air solar collector occurs.

One can use the obtained results in development and improvement of technical means for fruit drying to improve technological and energy efficiency of the process.

Author Biographies

Serhiy Korobka, Lviv National Agrarian University Volodymyra Velykoho str., 1, Dublyany, Ukraine, 80381

PhD, Senior Lecturer

Department of Energy

Mykhailo Babych, Lviv National Agrarian University Volodymyra Velykoho str., 1, Dublyany, Ukraine, 80381

PhD

Department of Energy

Roman Krygul, Lviv National Agrarian University Volodymyra Velykoho str., 1, Dublyany, Ukraine, 80381

PhD

Department of Energy

Andriy Zdobytskyj, Lviv National Agrarian University Volodymyra Velykoho str., 1, Dublyany, Ukraine, 80381

PhD

Department of operation and technical service of machines named after professor Semkovich O. D.

References

  1. Englmair, G., Dannemand, M., Johansen, J. B., Kong, W., Dragsted, J., Furbo, S., Fan, J. (2016). Testing of PCM Heat Storage Modules with Solar Collectors as Heat Source. Energy Procedia, 91, 138–144. doi: 10.1016/j.egypro.2016.06.189
  2. Horta, P., Osório, T. (2014). Optical Characterization Parameters for Line-focusing Solar Concentrators: Measurement Procedures and Extended Simulation Results. Energy Procedia, 49, 98–108. doi: 10.1016/j.egypro.2014.03.011
  3. Chamoli, S. (2013). Exergy analysis of a flat plate solar collector. Journal of Energy in Southern Africa, 24 (3), 8–13.
  4. NASA Surface meteorology and Solar Energy. Available at: http://eosweb.larc.nasa.gov
  5. Vishwakarma, D., Kale, J. (2017). Experimental study and analysis of solar air heater using of various inlet temperatures. International Journal of Research, 5 (10), 76–80. doi: 10.5281/zenodo.1039619
  6. Sabiha, M. A., Saidur, R., Mekhilef, S., Mahian, O. (2015). Progress and latest developments of evacuated tube solar collectors. Renewable and Sustainable Energy Reviews, 51, 1038–1054. doi: 10.1016/j.rser.2015.07.016
  7. Solar energy – Solar thermal collectors – Test methods. International Standard. ISO/FDIS 9806:2013(E).
  8. Syvoraksha, V. Yu. et. al. (2003). Teplovi rozrakhunky heliosystem. Dnipropetrovsk: Vyd-vo DNU, 132.
  9. Daffi, Dzh., Bekman, U. A. (1987). Teplovye processy s ispol'zovaniem solnechnoy energii. Moscow: Mir, 420.
  10. Duffie J. А., Beckmаn W. А. Solar engineering of thermal processes. John Wiley & Sons, 2013. 910 p. doi: 10.1002/9781118671603
  11. ASHRAE Standard 93-1986 (RA 91) Metods of Testing to Determine The Thermal Performance of Solar Collektors, American Society of Heating, Refrigerating and Air-Conditioning Engineers Inc (2002). Atlanta, USA.
  12. Hematian, A., Ajabshirchi, Y., Bakhtiari, A. (2012). Experimental analysis of flat plate solar air collector efficiency. Indian Journal of Science and Technology, 5 (8), 3183–3187.
  13. Shemelin, V., Matuska, T. (2017). Detailed Modeling of Flat Plate Solar Collector with Vacuum Glazing. International Journal of Photoenergy, 2017, 1–9. doi: 10.1155/2017/1587592
  14. Vega, E. V., Noh-Pat, F. (2014). Validation of the Simulation of Solar Air Collector Prototypes. Energy Procedia, 57, 2295–2304. doi: 10.1016/j.egypro.2014.10.237
  15. Ondieki, H. O., Koech, R. K., Tonui, J. K., Rotich, S. K. (2014). Mathematical Modeling Of Solar Air Collector With a Trapezoidal Corrugated Absorber Plate. International Journal of Scientific & Technology Research, 3 (8), 51–56.
  16. Labai, V. Y. (2004). Teplomasoobmin. Lviv: Triada Plius, 260.
  17. Miheev, M. A., Miheeva, I. M. (1977). Osnovy teploperedachi. Moscow: Energiya, 344.
  18. Fokin, V. M., Boykov, G. P. Vidin, Yu. V. (2005). Osnovy energosberezheniya v voprosah teploobmena. Moscow: Mashinostroenie, 192.

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Published

2018-05-24

How to Cite

Korobka, S., Babych, M., Krygul, R., & Zdobytskyj, A. (2018). Substantiation of parameters and operational modes of air solar collector. Eastern-European Journal of Enterprise Technologies, 3(8 (93), 16–28. https://doi.org/10.15587/1729-4061.2018.132090

Issue

Section

Energy-saving technologies and equipment