Optimization of geometrical parameters of a solar collector coupled with a thermal energy storage system

Abstract

Solar thermal collector is a device allows the conversion of solar radiation on useful thermal energy (heat). This technology has become mature and manageable. However, because its input comes from an intermittent source (sun) its production is variable during the day; also it's vulnerable to climatic conditions. To adopt this technology, it is therefore necessary to invest in energy storage means or to use a secondary energy source. In this work, a solar thermal collector has been studied and modeled. The objective of this study consists of; firstly, analyze the impact of the geometrical form of the absorbing surface on the solar collector's thermal performance. Three geometries are tested, namely flat, triangular and corrugated. The depth and period of the last two configurations is low to not affect the collector dimensions. The solar collector is evaluated under a hot climate considering the meteorological data of Er-rachidia city (Morocco). The second part of the present study consists of integrating a latent heat storage system using Phase Change Materials (PCM) to store part of the heat and exploit it during the night. Integrating PCM in this system is a relevant technique to overcome the problem of intermittency of solar energy. Moreover, according to the finding of this study it allows significant improvement of the solar collector thermal performance. The temperature remains locked in acceptable values with a deviation of 6'C from the case without PCM during the last hours of the night.