Heating and energy performances of a dynamic Trombe wall incorporating phase change materials under different operation modes

Dynamic Trombe wall incorporating PCMs (DTWP) is promising for effectively utilizing solar energy and latent heat storage to achieve building energy saving and different operating modes of the DTWP have different functions corresponding to different thermal and energy performances. However, the suitable operation mode for this system is still unclear. Therefore, in this research, the heating and energy performances of the DTWP system with different operation modes and companion static concrete and PCM Trombe walls under a typical winter day in a cold climate were comprehensively investigated using the corresponding CFD model validated by experimental data. The main results are: (1) The DCNC mode(fully closed vents of the thermal storage wall during daytime and nighttime) showed significant decreases in heat loss and good heating performance for the DTWP system; (2) The DCNC mode could extend the time lag and the thermal comfort duration, and showed significantly improved energy saving by 97.6 %; (3) Compared to the DONO mode (opened vents of the thermal storage wall during daytime and nighttime), the DCNC mode could decrease the indoor temperature stratification by 53.7 % and 67.7 % at noon and midnight, respectively; (4) The air velocity near the outer surface of the energy storage wall and the inner surface of the glazing layer is higher than in the other regions at noon and midnight, respectively. The findings would provide guidance for the application and practical operation optimization of DTWP in cold climate regions.