Mathematical model for calculating solar radiation on horizontal and inclined surfaces for the conditions of Yakutsk

Abstract

The purpose of this research is to develop a simple calculation technique for solar flux density on horizontal and inclined surfaces to allow estimation of the amount of heat energy entering a hybrid system of solar heat supply at any time. Based on the suggested method corresponding software is developed for defining solar flux on horizontal and inclined surfaces using measurement data of maximum daily solar radiation. Hourly values of total and diffuse solar radiation on horizontal surface are defined, as well as average daily, monthly and annual values of total solar radiation. The obtained calculation results are compared to the existing reference, experimental and calculation data on total solar radiation falling on horizontal surface in the city of Yakutsk. The calculated solar flux values show sufficient consistency with the reference materials and NASA SSE database. The paper provides description of the method for calculating specific solar heat flux on inclined surface with known heat fluxes of direct and diffuse solar radiation falling on horizontal surface.