Influence of Meteorological Factors on the Thermal Loss Coefficient of Light-Absorbing Heat Exchange Panels of Flat-Plate Solar Water Heating Collectors through Transparent Coatings of Their Casings

Abstract

The results of computational studies aimed at determining the coefficient of thermal losses of light-absorbing heat-exchange panels (LAHP) of flat-plate solar water-heating collectors (FPSWHC) through their translucent coatings (TC) are presented. The calculations take into account the effect of free and forced convection on the external surface of the TC, as well as on the convective heat transfer coefficient and the FPSWHC tilt, the atmospheric transparency, and the air humidity on the total heat transfer coefficient from the external surface of the TC to the environment. An example is given to test the proposed approach for practical use to determine the values of $$~\alpha _{{{\text{i}}{{{\text{n}}}_{{{\text{w}} - {{c}_{1}}}}}}}^{\Sigma }$$ , $$\alpha _{{{\text{ex}}{{{\text{t}}}_{{{{c}_{2}} - {\text{amb}}}}}}}^{\Sigma }$$ , and their convective and the radiant components, and also the degree of their influence on the value of $${K}_{{{{c}_{{{\text{w}} - {\text{amb}}}}}}}^{~}$$ .