Thermal Buffering Performance of a Propyl Palmitate/Expanded Perlite-Based Form-Stable Composite: Experiment and Numerical Modeling in a Building Model

A phase change material (PCM) composite was prepared by impregnating propyl palmitate in expanded perlite (EP, as a support matrix), and its thermal buffering performance was tested in building applications. Five composites with varying PCM contents, i.e., 60, 55, 50, 45, and 40%, were prepared, and the composite with 55 wt % (EP-55) was chosen for thermal buffering performance analysis. All composite samples showed melting between 18.5 and 18.8 degrees C (as a PCM), while attenuated total reflection-infrared spectroscopy analysis confirmed simple physical adsorption occurring between the PCM and EP. Differential scanning calorimetry measurements (EP-55) showed a phase change enthalpy of 81.98 +/- 1 J g(-1), and stable performance during 1000 thermal cycles with the EP-55 composite confirmed appreciable thermal stability and reliability. The thermal buffering performance of the composite was tested in a building model, which was simulated using COMSOL Multiphysics 5.5. The unsteady-state energy (conduction/convection/radiation and latent heat of a PCM) transport from a source to the building was expressed mathematically along with its boundary conditions. The model was validated using a blank and with a composite, which was later applied to predict another unknown case. The model-predicted temperatures could very closely match (< +/- 4.0%) with experimental values.

Automated summary

A phase change material (PCM) composite was prepared by impregnating propyl palmitate in expanded perlite for thermal buffering in building applications. The composite showed stable phase change enthalpy and thermal stability during 1000 thermal cycles, with the model-predicted temperatures closely matching experimental values. COMSOL Multiphysics 5.5 simulation further validated the thermal buffering performance of the composite in building applications.