A novel measurement method of thermal performances for an improved thermal storage concrete with microencapsulated phase change materials

Abstract

Integrating micro-encapsulated phase change materials into concrete member is among the effective strategies to optimize its thermal properties. However, the addition of microencapsulated phase change materials changes the meso-structure and heat storage of concrete, which gives rise to the difference in measurement method of thermal properties between common concrete and concrete with micro-encapsulated phase change materials. The primary aim of this paper is to develop an experimental model that takes into consideration both the structure and phase-transition characteristics of concrete with micro-encapsulated phase change material. The developed experimental model consists of three Modules that form different thermal boundary conditions to test specific heat capacity, latent heat, thermal conductivity, and heat attenuation. To investigate the effect of environment temperature on the thermal properties, three groups of concrete slabs with different micro-encapsulated phase change material dosage were and fabricated and tested. Results shown that the environment temperature has little effect on both specific heat capacity and thermal conductivity of concrete without micro-encapsulated phase change material, while significantly affects that of concrete containing micro-encapsulated phase change material. The specific heat capacity of concrete with 5.0 % micro-encapsulated phase change material was 1.273 J/g °C at around 28 °C, yet 0.958 J/g °C at around 18 °C.The thermal conductivity of concrete with micro-encapsulated phase change material was affected by both paraffin state and dosage. The thermal conductivity of the concrete with 5.0 % micro-encapsulated phase change material reduced by 8.44 % when the state of paraffin changed from solid to liquid. The latent heat of concrete with micro-encapsulated phase change material were enhanced. Additionally, the heat attenuation ascends by 32.34 % when the MPCM dosage increase from 0.0 % to 5.0 %.