Experimental and numerical study of epoxy resin-based composite phase change material in packed-bed thermal energy storage system for ventilation

Abstract

Air heating of ventilation system occupies large energy consumption of buildings. Using phase change material (PCM) in active thermal energy storage system (TES) has practical significant to avoid unstable input and improve energy capacity. This work proposed a packed-bed TES system with solar collector for ventilation, by employing the novel epoxy resin-based composite PCM without capsule shell as fillers. In experiment, two types composites were first prepared and compared: the epoxy resin-based composite with Al additives has loading capacity up to 65% and a latent heat of 116.7 J kg−1, which shows better thermal performance than that of the Al-based composite (maximum 25%, 46.92 J kg−1). Then, a numerical model of TES system was built, validated, and then used to simulate the outlet temperature variation of air. Simulation results shows the designed TES system is beneficial to stabilize output temperature. Therefore, when the energy storage process is from 7:30 am to 17:30 pm, the utilization efficiency for composite filler system of 51.1 % is higher than that of pure PCM filler system of 49.7 %. At last, determining the phase change temperature of the composite at around 25 °C leads to an efficiency improvement around 22 %.