Combined Convective-Radiative Thermal Analysis of a Solar Flat-Plate Collector

A model for the combined spectral radiative, conductive and convective heat transfer analysis of solar water heaters is presented. The radiation aspect of this model is based on the spectral distribution of the solar irradiance and spectrally selective properties of the system components. The convective equations that were used are based on well-established empirical models. The heat transfer characteristics of the solar water heater are determined by simultaneously solving a nonlinear system of energy balance equations for the various physical components using an iterative approach. The model is used to predict temperatures and heat fluxes for a typical flat-plate solar collector for various geometries and conditions i.e. flow rates, solar irradiances and spectral properties.