光伏直热蓄热墙体特性实验研究

Experimental Study on Thermal Characteristics of Photovoltaic Direct-Heating Thermal Storage Wall

摘要: 在“碳达峰、碳中和”目标驱动下，降低建筑能耗成为关键任务。本文提出一种新型光伏直热蓄热墙体系统，将光伏电力直接驱动电加热丝发热，热量被墙体吸收后通过热对流/辐射向室内供暖，实现蓄热与供暖终端一体化。通过实验研究了电加热丝底部横向排布方式下，顶部保温封闭与顶部开孔两种工况的性能。结果表明：1) 保温封闭工况下，系统光伏发电量3525 Wh (转换率11.3%)，墙体蓄热量1731.23 Wh (蓄热率51%)，单位体积蓄热量6612.81 Wh/m³，夜间放热持续10小时；2) 开孔工况蓄热率降至43.3%，放热时间缩短至6小时，但白天室温提升更快。保温封闭工况在蓄热性能、夜间供暖持续性方面显著更优，为建筑光伏蓄热系统提供了高效解决方案。

Abstract: Under the “Carbon Peak and Carbon Neutrality” targets, reducing building energy consumption is critical. This study proposes a novel photovoltaic direct-heating thermal storage wall system, where PV electricity drives electric heating elements to generate heat, absorbed by the wall and released indoors via convection/radiation, integrating thermal storage and heating terminal functions. Experiments evaluated two configurations with bottom-mounted horizontal heating elements: top-insulated sealed and top-opened. Key results show: 1) For the insulated case, PV generation reached 3525 Wh (conversion efficiency: 11.3%), wall heat storage was 1731.23 Wh (storage ratio: 51%), volumetric storage density hit 6612.81 Wh/m³, with 10-hour nighttime heat release; 2) The opened case had reduced storage ratio (43.3%) and shorter discharge duration (6 h), but faster daytime room temperature rise. The insulated configuration demonstrates superior heat retention and extended nighttime heating, providing an efficient solution for building-integrated PV thermal storage systems.