Enhancing thermal performance of energy storage concrete through MPCM integration: An experimental study

Abstract

Phase change materials melt and solidify at different temperature ranges called Phase change hysteresis. This phenomenon should be understood and evaluated in order to adequately design energy storage concretes for applications. Although many studies have analyzed the phase change process in pure - phase change materials such as paraffin. However, there is not enough information about the Phase change hysteresis of energy storage concrete. In order to realistically reproduce the working condition of concrete. This study explores phase change hysteresis in energy storage concrete slabs, focusing on the impact of microcapsule concentration and temperature change rate on thermal efficiency. Experiments were conducted to analyze the thermophysical properties, particularly observing the variations in specific heat capacity and phase transition temperatures. Results showed that increasing the microcapsule concentration enhances the specific heat capacity and latent heat of phase change, while faster temperature changes intensify hysteresis effects. Compared with the results of previous studies. Phase change hysteresis is more significant due to the pore and complex structure of energy storage concrete that impedes heat transfer. The experimental latent heat values were approximately 75 % of theoretical predictions, likely due to microcapsule damage and microstructural impacts on heat transfer. The study's findings are crucial for optimizing the thermal performance of energy storage concrete.