Investigation of Mg-Zn-Al metal alloys as new PCMs for latent heat energy storage applications

Abstract

The main objective of this thesis is to investigate metal alloys as phase change material (PCM) for thermal energy storage (TES) applications. In particular, This work consists to analyze and characterize a set of binary and ternary metal alloys based on different compositions of Mg-Al-Zn mixtures, in order to identify new eutectic and peritectic compositions with adequate melting temperatures combined with appropriate thermophysical properties for their use as PCM storage media at high temperature for concentrated solar power (CSP) and industrial waste heat recovery applications among others. The first stage of this experimental work consists on synthesis of the selected metal alloys by using different routes of preparation. When the materials are synthesized a complete structural analysis is conducted by combining different techniques such as X-ray diffraction (XRD) and scanning electron microscopy (SEM). The second stage of this work is to determine the most relevant thermophysical properties of these materials in this field such as the melting temperature, the heat capacity, the latent heat, the thermal conductivity, among others. The third stage is to investigate the long term thermal stability of the studied PCM by accelerated thermal cycling tests. The final stage consists to investigate the compatibility study between the selected alloys and different containment materials in order to identify the most suitable stainless steels that can be used in the construction of TES unit.