Solar assisted heat pump performance with combined latent and thermochemical storage

This study investigates a solar-assisted heat pump integrated with a hybrid dual thermal energy storage system (DualTES) composed of a phase change material (PCM) unit and a thermochemical (TC) storage unit. A dynamic thermal-thermodynamic model was developed for the heat pump, PVT collector, PCM storage, TC storage, and source-side coupling loop. Five configurations were compared: HP-only, PVT-only, PCM-only, TC-only, and DualTES. Results showed that direct PVT assistance alone yields only a limited performance improvement, whereas PCM storage provides a clear daily benefit through sustained source-temperature support. TC storage produces a different response, characterized by a short-duration supplementary thermal contribution. Among all cases, DualTES achieved the best overall transient performance, with the highest daily COP (2.830), peak COP (3.361), and maximum source temperature (18.00 °C). Relative to PCM-only, DualTES increased the daily COP by 0.34% and the peak COP by 2.69%, while reducing the critical-period cumulative source-temperature deficit by 6.60%. Steady-state analysis over a condenser-load range of 5–50 kW further confirmed that DualTES maintains the highest COP and lowest compressor power. The results indicate that PCM dominates the daily storage contribution, while TC acts mainly as an auxiliary peak-support branch under the adopted control strategy. Under the prescribed operating scenario, the hybrid configuration provided a modest daily COP improvement and greater transient peak support than PCM-only, with the comparison reflecting both storage integration and the assigned control targets.