Space heating performance of novel ventilated mortar blocks integrated with phase change material for floor heating

摘要

Energy flexible building is promising for the penetration of renewable energy, and electric heating floor with built-in ventilation duct is one important form. However, the thermal and energy performance of such thermal active system is still unclear, which makes it necessary to develop a reliable thermal model of such system. In this research, a scale experimental system was established to test the space heating performance and energy consumption characteristics of four ventilated mortar blocks under different operational modes, and three blocks were integrated with different distributions of micro-encapsulated phase change material (PCM). An analysis was conducted of the critical parameters including the surface temperature of mortar block, the average temperature of space air, the temperature of black globe and the power consumption. It was found out that when PCM was concentrated on the upper part, and ventilation started at the same time as heating, the heating power consumption was increased by up to 41.5% compared to the heating without ventilation. For a further predictive control, a simplified state space model was also established and validated by the experimental data. Additionally, the impact of some geometrical and operational parameters was also analysed based on the model, including the thickness of mortar block, the air speed and the diameter of tube. It was demonstrated that the thickness of block had the most significant impact on the surface temperature of mortar block, ventilation rate had a considerable impact on the thermal responsiveness of indoor air, and tube diameter had a comprehensive impact on the thermal performance of block and space air.