The mature and scale utilization of renewable energy is restricted by the deficient efficiency of latent heat storage (LHS) technology. To address this, an innovative Vicsek fractal fin is first proposed herein for the heat charging/discharging rate enhancement. The phase transition behavior and thermal characteristics of the innovative LHS unit are solved numerically and compared to the traditional one, employing the enthalpy–porosity algorithm and a two-dimensional transient model. The results indicate that Vicsek fractal fins remarkably promote the thermal efficiency of LHS units. Compared to the traditional LHS units, innovative LHS units with Vicsek fractal fins, respectively, reduce the melting/solidification duration by 16.1% and 28.7%. The melting process is divided into early thermal conduction, subsequent convective thermal transport, and later thermal conduction, while solidification processes are dominated by the initial natural convection and the subsequent continuous heat conduction. Moreover, the impact of free convection is higher on melting processes than on solidification processes. Importantly, the efficient heat transfer path of Vicsek fractal fins allows the inherent natural convection suppression to be much weaker than the improvement level of heat transfer efficiency, facilitating the interstitial thermal transport between the phase change material (PCM) and fins and improving the overall temperature uniformity of LHS units.

中文翻译：

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VICSEK 分形鳍片增强的潜热蓄热单元的性能改进评估

可再生能源的成熟和规模利用受到潜热蓄热（LHS）技术效率低下的制约。为了解决这个问题，本文首先提出了一种创新的 Vicsek 分形翅片，用于提高热充电/放电率。采用焓-孔隙度算法和二维瞬态模型，对创新 LHS 单元的相变行为和热特性进行了数值求解，并与传统单元进行了比较。结果表明，Vicsek 分形翅片显着提高了 LHS 单元的热效率。与传统的 LHS 装置相比，具有 Vicsek 分形翅片的创新 LHS 装置分别将熔化/凝固持续时间缩短了 16.1% 和 28.7%。熔化过程分为早期热传导、后续对流热传输、和后来的热传导，而凝固过程则以最初的自然对流和随后的连续热传导为主。此外，自由对流对熔化过程的影响比对凝固过程的影响更大。重要的是，Vicsek分形翅片的高效传热路径使得固有的自然对流抑制比传热效率的提高水平要弱得多，有利于相变材料（PCM）和翅片之间的间隙热传递，提高整体温度LHS 单位的一致性。自由对流对熔化过程的影响大于对凝固过程的影响。重要的是，Vicsek分形翅片的高效传热路径使得固有的自然对流抑制比传热效率的提高水平要弱得多，有利于相变材料（PCM）和翅片之间的间隙热传递，提高整体温度LHS 单位的一致性。自由对流对熔化过程的影响大于对凝固过程的影响。重要的是，Vicsek分形翅片的高效传热路径使得固有的自然对流抑制比传热效率的提高水平要弱得多，有利于相变材料（PCM）和翅片之间的间隙热传递，提高整体温度LHS 单位的一致性。