Comparative Study of Phase Change Material Characterization Methods

Modeling latent heat thermal energy storage systems is mostly achieved by implementing the enthalpy curve of the phase change material (PCM) into a numerical model. Then, the accuracy of the model depends on the accuracy of the enthalpy curve. The objective of this study is to compare the enthalpy curve obtained with four different characterization methods. Two methods are based on differential scanning calorimeter (DSC) experiments with dynamic and step modes. By modeling an experimental set-up, which contains a greater mass of PCM than with DSC, the two other methods use inverse methods to identify the analytical model describing the phase change process. Paraffin RT58, a PCM suitable for domestic hot water (DHW) storage, is selected for this study. Results highlight the same enthalpy difference for each method between 20 degrees C and 65 degrees C. Even if the end of the phase change process is described slightly differently for the two DSC methods than for the two inverse methods, results are mainly similar and all methods give a correct description of the phase change process. Conclusions are only relevant for the studied PCM, which does not undergo supercooling.