Selection of phase change material for improved performance of Trombe wall systems using the entropy weight and TOPSIS methodology

Abstract

The past decade has witnessed a lot of technological advancement towards the use of renewable and sustainable energy resources, these efforts are geared towards mitigating the effect of climate change and to make our environment safe and habitable. Today, buildings account for over 40% of the world's total energy consumption. Thermal energy storage in buildings contributes significantly to the reduction of building energy demand by releasing its stored energy when the demand arises. Trombe walls are used for thermal energy storage and delivery in buildings and thus regulates the rooms ambient temperature. A lot of studies have considered the use of phase change materials for latent heat thermal energy storage in Trombe walls in order to improve its performance. The selection of phase change materials for optimum Trombe wall performance was considered in this article, the weights of the various criteria were determined using the entropy weight method while the various alternative phase change materials were ranked using the technique for order preference by similarity to ideal solution (TOPSIS) methodology. The four criteria considered were the heat of fusion, thermal conductivity, density, and cost. A total of eleven commonly available phase change materials were considered in this study, with phase change temperatures within the range 18 C–28 C which corresponds to the average temperature range for human comfort. The result had the thermal conductivity was assigned the highest weight of 72.12% while the eutectic combination of capric acid and palmitic acid ranked the best at 95.1% for Trombe wall application.