Akademik Veri Yönetim Sistemi
Applied Thermal Engineering, cilt.278, 2025 (SCI-Expanded)
The growing need for decarbonization and efficient use of renewable energy highlights the importance of integrating thermal energy storage (TES) units with heating systems. This study presents a numerical assessment of a TES unit coupled with solar-assisted heat pump (SAHP) in terms of thermal charging/discharging times, latent heat utilization, and contribution to the peak load clipping. The model was established based on preliminary experimental works, and the dynamic simulations were carried out for the selected representative days in the heating period. Four different phase change materials were considered as TES materials within the unit, and water was also included as a TES material to constitute a reference basis for comparisons. The TES unit was thermally charged by solar collectors. Then, pre-stored thermal energy from the TES was used by the SAHP as a heat source during peak hours between 17:00–22:00. The simulation results showed that all PCMs completed melting process during charging by solar energy, except RT28HC, due to its high latent heat capacity. During the SAHP heating process via thermal discharge, three out of the four PCMs (RT24HC, RT26, and RT28HC) failed to solidify completely, leaving 22 % to 44 % of their latent heat unreleased. Nevertheless, the heat release of RT28HC was 47 % to 153 % greater compared to that of the other PCMs, showing the significant potential of this PCM. Additionally, depending on the month and utilized PCM, peak clipping rates between 15 % and 30 % were obtained. The most significant barrier in front of PCM utilization was insufficient thermal conductivity, and increasing the effective thermal conductivity of the selected RT28HC from keff = 0.2 W/mK to 0.4 W/mK improved the rate of latent heat release from 70.4 % to 91.5 %. It was inferred from the outcomes that using PCM can be recommended if heat transfer enhancement techniques are available. Otherwise, water can be considered a more feasible TES material in such systems.