An analytical model for the energy storage potential of phase change materials supported by polymeric colloidal aerogels

Abstract

Effective thermal energy storage has become one of the well-recognized aspects of modern energy management. Phase change materials (PCMs) shape-stabilized in the porous structure of porous support materials are one of the candidates to reach stable and effective thermal energy storage. This study presents an analytical model for the prediction of thermal energy storage density and thermal conductivity of colloidal aerogels impregnated by a PCM (TCAP model). The TCAP model is a series-parallel model that combines the thermal conductivity of the structure of the supporting aerogel and the thermal characteristics of the impregnated PCM. To validate the model, a mesoporous resorcinol-formaldehyde aerogel with an average pore diameter of 5.2 nm is synthesized, and two types of polyethylene glycol PCMs (PEG600 and PEG2000) are impregnated into the porous structure of the supporting material. The results confirm that the TCAP model can accurately predict the thermal energy storage characteristics of the system in terms of energy storage rate and density. Based on parametric studies, the highest heat capacity that can be achieved in a resorcinol-formaldehyde aerogel/polyethylene glycol is 35 kJ/kg.k with a ΔT of 40 K. On the other hand, it can be predicted that when ΔT increases from 10 K to 20 K, the energy storage of the system will change in the range of 52 % to 74 %. Moreover, The TCAP model developed in this study can be used to design/optimize energy storage materials for various applications such as smart buildings, solar energy storage devices, environmental thermal management systems, wearable thermal management devices, and temperature control in electronics.