Modification of thermal properties for a composite of stearic acid/kaolin used as a phase change material by infrared camera analysis approaches

In order to overcome the energy crisis and environmental issues, many types of research have been done. Thermal energy storage (TES) is a cost-effective method for maintaining thermal equilibrium and ban wasting energy. Phase change materials (PCMs) can save large amounts of thermal energy from the surrounding by changing the phase from solid to liquid depending on the phase change temperature of the employed PCM, and release the absorbed energy in a vice versa process. Organic materials such as paraffin waxes, fatty acids, etc. are widely used PCMs in the past few years that have some significant properties including available in a large range, inflammable, non-reactive, etc. Clay minerals, such as kaolinite, diatomite, perlite, etc. widely have been investigated as supporting material to limit the PCM from leakage and prepare form-stable phase change material (FSPCM). PCMs could be embedded in a supporting material via various methods such as melt and vacuum impregnation, micro and macro encapsulation and so on.In this study stearic acid (SA) impregnated into the kaolin with a mass fraction of 50%. The heat storage behavior of the obtained composites is determined by using an infrared camera. Figure 1 demonstrates the heating trend of FSCPCM and also the slope of the trend was computed to find the area that composite absorbs energy. In Fig. 1a, the infrared camera curves indicate that FSPCM melts at around 52 °C that has a good agreement with the melting point of raw stearic acid and can save energy as phase changing happens. The peaks specified in Fig. 1b indicating the thermal energy saving area in Fig. 1a that is computed about 2750.4 by Trapezoidal integration method.