能源研究与管理2025，Vol.17Issue(4)：33-42,10.DOI:10.16056/j.2096-7705.2025.04.005
熔盐相变热缓冲层对槽式太阳能集热系统热力特性的影响
Influence of Molten Salt Phase Change Thermal Buffer Layer on the Thermodynamic Characteristics of Parabolic Trough Solar Collector Systems
摘要
Abstract
Aiming to address the fluctuation in thermal performance of parabolic trough solar collector(PTSC)systems induced by the intermittency and instability of solar radiation,this study is conducted on a PTSC system with a solar aperture area of 15.3 m2.Binary nitrate molten salt(ω(KNO3)40％+ω(NaNO3)60％)is utilized as the phase change material(PCM)thermal buffer layer,and WRY-320 heat transfer oil serves as the heat transfer fluid(HTF).A combined approach of experimental verification and numerical simulation is employed to systematically investigate the effects of adding a PCM layer and varying PCM layer thicknesses on the thermodynamic characteristics of the collector system.The results indicate that,the root mean square error(RMSE)between the numerical model and the experimental data is 0.032,validating the scientific rigor of the simulation method.Incorporating a PCM layer can significantly mitigate the impact of solar radiation fluctuations on the system.Within 60 minutes after heating cessation,the average HTF temperature in the PCM-free system decreased by 7.5 ℃,whereas that in the PCM-equipped system increased by 2.3 ℃.The average cooling rate during the cooling phase was only 60％of that in the PCM-free system.Compared with the PCM-free system,the total heat storage capacity increased by 33.2 MJ,and the heat storage efficiency was enhanced by 18.5％.When the PCM layer thickness ranged from 2.6 mm to 32.6 mm,the HTF heat gain and average oil temperature at the end of heating exhibited a trend of first increasing and then decreasing,while the total heat storage capacity and heat storage efficiency increased continuously.Among all tested thicknesses,the 22.6 mm-thick PCM layer can balance normal heat demand and high heat storage efficiency,achieving the optimal comprehensive performance.Collectively,experimental and numerical results confirm that the binary nitrate molten salt-based PCM layer effectively mitigates PTSC system thermal performance fluctuations caused by solar radiation intermittency.The 22.6 mm-thick PCM layer is identified as the optimal thickness balancing heat demand and storage efficiency,providing a quantitative basis for the optimization of heat storage structures in PTSC systems.关键词
槽式太阳能集热系统/相变储热/二元硝酸熔盐/热力特性/PCM层厚度Key words
parabolic trough solar collector(PTSC)system/phase change heat storage(PCHS)/binary nitrate molten salt/thermodynamic characteristics/phase change material(PCM)layer thickness分类
能源科技引用本文复制引用
XING Wenqing,WANG Hua,WANG Di..熔盐相变热缓冲层对槽式太阳能集热系统热力特性的影响[J].能源研究与管理,2025,17(4):33-42,10.基金项目
河南省科技攻关项目(232102321088) （232102321088）
