Numerical Study on Thermal Performance of Radiant Panels Coupled with V-Shaped Grooves and Phase Change Materials

This study focuses on a proposed aluminum alloy radiant panel with 60° V-shaped grooves and integrated copper tubes. A numerical model of this novel grooved phase change material (PCM)-integrated radiant panel was established via Fluent 2022 R1 software. Through numerical simulations, the complete melting and solidification processes of two PCMs (n-hexadecane and LTXC-PCM-A-18) were analyzed, and differences in their phase change heat transfer performance were compared—revealing the role of the groove structure in enhancing PCM heat transfer and the material-structure compatibility. Results indicate that the groove structure effectively enhances convective heat transfer in the PCM liquid phase. During the melting stage, LTXC-PCM-A-18 exhibited a preheating rate of 0.00125 K/s, which is 67% higher than that of n-hexadecane (0.00075 K/s); its liquid fraction growth rate (0.0002 s−1) was 2.67 times that of n-hexadecane, and the melting completion time was accelerated by 20% (2000 s). During solidification, LTXC-PCM-A-18’s initial cooling rate (0.0006 K/s) was 50% higher than that of n-hexadecane (0.0004 K/s), with a liquid fraction decay rate twice that of n-hexadecane. Additionally, its solidification temperature plateau was 1 K higher, providing superior thermal output stability. These findings reflect two distinct technical strategies: “steady-state temperature control” and “dynamic regulation.” n-Hexadecane exhibits smoother melting and solidification processes, making it suitable for continuous heating applications. In contrast, LTXC-PCM-A-18 demonstrates superior thermal responsiveness and phase change efficiency, aligning with intermittent heating requirements. This study provides quantitative guidance for PCM selection in grooved radiant panels.