SOLAR ABSORBER WITH A STRUCTURED SURFACE – A WAY TO INCREASE EFFICIENCY

Authors

DOI:

https://doi.org/10.14311/AP.2019.59.0134

Keywords:

solar absorber, hydroforming, multiple reflections, absorption efficiency, LS-DYNA

Abstract

The basic idea of a solar absorber’s thermal gain increase is the keyhole effect utilization during which the radiation is absorbed by multiple reflections on cavity walls. The lattice of pyramidal or conical cavities on the solar absorber surface can be formed to create a structured surface leading to its overall absorptivity increase and to a reduction of the surface absorptivity dependence on the solar radiation incident beam angle changes caused by the daily and annual solar cycles. This contribution concludes the results of simulations of the effect of cavity geometry, geographical position and absorber orientation on its thermal gain with respect to the technological manufacturability of cavities. Furthermore, the real construction of the absorber with a structured surface using laser welding and parallel hydroforming is briefly described.

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Author Biographies

  • Libor Mrňa

    Brno University of Technology,

    Institute of Scientific Instruments of the Czech Academy of Sciences

  • Jan Řiháček
    Brno University of Technology
  • Martin Šarbort
    Institute of Scientific Instruments of the Czech Academy of Sciences
  • Petr Horník
    Institute of Scientific Instruments of the Czech Academy of Sciences

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Published

2019-04-30

Issue

Vol. 59 No. 2 (2019)

Section

Articles

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How to Cite

Mrňa, L., Řiháček, J., Šarbort, M., & Horník, P. (2019). SOLAR ABSORBER WITH A STRUCTURED SURFACE – A WAY TO INCREASE EFFICIENCY. Acta Polytechnica, 59(2), 134-143. https://doi.org/10.14311/AP.2019.59.0134