Experimental analysis of the synergistic impact of fan and nocturnal thermal insulation on enhancing the thermal performance of latent-energy-storage solar air collectors

• Published in: Journal of energy storage Vol. 99; p. 113432
• Main Authors: Fu, Wenkai, Ge, Liming, Bo, Renfei, Gao, Yanna
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 10.10.2024
• Subjects: Forced convection; Nocturnal thermal insulation; Phase change material; Solar air collector; Wintery heating; Forced convection; Phase change material; Nocturnal thermal insulation; Wintery heating; Solar air collector
• ISSN: 2352-152X
• DOI: 10.1016/j.est.2024.113432

Solar air collectors equipped with energy storage functionality are widely utilized to address the mismatch between heat demand and supply periods during winter, effectively facilitating heating needs. However, phase change energy storage flat plate solar air collectors are hindered by inefficiencies, primarily due to the low rate of convective heat transfer and substantial nocturnal energy losses, which considerably undermine the overall energy efficiency of these collectors. In response to these challenges, a forced convection approach utilizing a fan was adopted to augment the convective heat transfer rate, and insulation was applied to glass panes overnight to curb energy wastage. Two solar air collector systems were constructed and examined: a natural convection-based energy storage solar air collector (NCSAC-PCM) and another solar air collector incorporating forced convection with nocturnal thermal insulation (FCSAC-PCM-NTI). Comparative experiments revealed that the combination of forced convection with nighttime insulation in the latter design led to an elevation in the mean indoor temperature by 1.4 °C, alongside a decrease in the temperature gradient variation within the space during the test period. Furthermore, this integration significantly enhanced the energy efficiency by 53.71 % and the exergy efficiency by 11.45 %. •The fan and nocturnal thermal insulation are coupling employed.•This integration enhanced indoor air temperature by 1.4 °C.•This integration significantly enhanced the energy efficiency by 53.73 %.•The integration increased exergy efficiency by 11.58 %.