Experimental and numerical study on the thermal performance of ventilated roof composed with multiple phase change material (VR-MPCM). (1st June 2020)

• Record Type: Journal Article
• Authors: Li, Han; Li, Jinchao; Xi, Chang; Chen, Wanhe; Kong, Xiangfei
• Is Part Of: Energy conversion and management. Volume 213(2020)
• Publication Date: 2020-06-01
• Subjects: Thermal storage system -- Phase change material -- Ventilated roof -- Passive cooling storage -- Building energy conservation; Direct energy conversion -- Periodicals; Energy storage -- Periodicals; Energy transfer -- Periodicals; Énergie -- Conversion directe -- Périodiques; Direct energy conversion; Periodicals; 621.3105
• DOI: 10.1016/j.enconman.2020.112836
• Languages: English
• ISSNs: 0196-8904

Abstract

Highlights: A novel ventilated roof composed with multiple phase change material was proposed. Experimental and numerical study on its thermal performance were introduced. The operation strategy and applicability was obtained by numerical research. Our findings provided guidelines for employing the novel roof in the buildings. Abstract: In the hot summer, roof is the prime location absorbed the most solar radiation for both residential and commercial buildings. Hence, enhancing the thermal performance of roofs is essential for reducing the heat gain thus building load. In this study, a novel ventilated roof composed with multiple phase change material (VR-MPCM) was proposed and its thermal performance was investigated experimentally and numerically. A contrast experiment was conducted in two full-scale chambers. The research results indicated that VR-MPCM can reduce the indoor peak temperature by 16.9–18.8%, and push back the peak temperature occurrence time by 30–50 min compared with the conventional ventilated roof (CVR). In addition, the cumulative heat flux during 4320 min demonstrated that the energy conservation rate of VR-MPCM can go up to 97.1% compared with the CVR. A verified three-dimensional transient heat transfer model was introduced for further research. Through the simulation research, intermittent opening of vents was found to be the best operating strategy for reducing heat gain. Regional comparison indicated that VR-MPCM in severe cold and cold climate zones had obvious energy saving potential. In conclusion, VR-MPCM has a potential of energy saving by reducing the diurnal heat gain and utilizing the nightly free cooling.