扩展表面在相变储热中的强化换热研究进展

Research Progress of Heat Transfer Enhancement for Extended Surface in Phase Change Thermal Storage

相变储热在节能、电力调峰等领域日益得到关注,然而相变材料热导率普遍较低,导致储热系统热性能较差。文中从强化换热角度出发,对以扩展表面技术强化相变储热单元热量传递相关的翅片、热管、翅片耦合热管或泡沫金属进行了综述。文献分析表明,上述强化换热元件均可显著提升储/释热效率,翅片结构和布置方式会影响相变材料的强化换热效果;热管与相变材料普遍有着较好的相容性,其对相变过程中的均温性较好;翅片耦合热管综合利用了二者之间的传热特性,且热管数量较翅片几何参数对相变材料的凝固/熔化影响更大。在未来研究中,通过拓扑优化获取几何结构更为优异的翅片、热管以及翅片与热管耦合对相变材料传热强化的机理具有重要的研究价值。

Phase change thermal storage has received increasingly concern in fields of energy conservation and peak-load regulation. However, generally speaking, the thermal conductivity of phase change materials is relatively low, which leads to poor performances of thermal energy storage system. From the respective of heat transfer enhancement, the research progress of heat transfer enhancement methods for extended surface, including fin, heat pipe, finned heat pipe and fin-metal foam coupling, in phase change thermal energy storage unit is summarized. Through literatures analysis, it can be seen that all of the mentioned heat transfer enhancement elements above could remarkably improve both charging and discharging rates of the phase change material. As for fins, the structure and arrangement ways could influence the effect of heat transfer. Heat pipes have good compatibility with phase change material in universality, and could dramatically improve temperature uniformity during phase transitions. Finned heat pipes utilize the heat transfer characteristics of both, and moreover, the number of heat pipes show greater influence on solidification and melting rates of phase change materials as compared to geometrical parameters of fins. In the future research, there is still important research value in obtaining excellent geometric structure through topological optimization and the mechanism of heat transfer enhancement by heat pipe and finned heat pipe.