Dual Phase Change Material Segmentation and Orientation Effects in Shell‐and‐Tube Latent Heat Storage: A Validated CFD Simulation

This study employs an in‐house CFD solver to simulate melting in single and dual phase change materials (PCMs) arrangements within a shell‐and‐tube heat exchanger for thermal energy storage via latent heat. Dual PCMs are configured radially and axially, with heat exchangers positioned horizontally, inclined, and vertically. Experiments on single PCM melting validate the simulation across different Reynolds numbers and PCM configurations. The research assesses thermal performance during transient melting, heat storage, and temperature uniformity, considering PCM type, configuration, orientation, and inlet temperature. Results show that conduction and convection modes in dual PCMs enhance heat transfer, with natural convection playing a key role. Dual PCM setups outperform single PCM, increasing energy storage by 15.5% and reducing outlet temperature fluctuations by 12.8%. The horizontally oriented radial dual PCM is the most efficient, improving natural convection and reducing melting time by 22.5% compared to single PCM. Higher inlet temperatures accelerate melting but decrease efficiency, emphasizing the importance of thermal matching. These insights support the development of energy‐efficient PCM heat exchangers for solar thermal energy, waste heat recovery, and heating, ventilation, and air conditioning applications.