Najim Farqad T, Mohammed Hayder I, Al-Najjar Hussein M Taqi, Thangavelu Lakshmi, Mahmoud Mustafa Z, Mahdi Jasim M, Tiji Mohammadreza Ebrahimnataj, Yaïci Wahiba, Talebizadehsardari Pouyan
Electrical Engineering Department, College of Engineering, Al-Iraqia University, Baghdad 10071, Iraq.
Department of Physics, College of Education, University of Garmian, Kalar 46021, Iraq.
Nanomaterials (Basel). 2022 Jan 26;12(3):403. doi: 10.3390/nano12030403.
Employing phase-change materials (PCM) is considered a very efficient and cost-effective option for addressing the mismatch between the energy supply and the demand. The high storage density, little temperature degradation, and ease of material processing register the PCM as a key candidate for the thermal energy storage system. However, the sluggish response rates during their melting and solidification processes limit their applications and consequently require the inclusion of heat transfer enhancers. This research aims to investigate the potential enhancement of circular fins on intensifying the PCM thermal response in a vertical triple-tube casing. Fin arrays of non-uniform dimensions and distinct distribution patterns were designed and investigated to determine the impact of modifying the fin geometric characteristics and distribution patterns in various spatial zones of the heat exchanger. Parametric analysis on the various fin structures under consideration was carried out to determine the most optimal fin structure from the perspective of the transient melting evolution and heat storage rates while maintaining the same design limitations of fin material and volume usage. The results revealed that changing the fin dimensions with the heat-flow direction results in a faster charging rate, a higher storage rate, and a more uniform temperature distribution when compared to a uniform fin size. The time required to fully charge the storage system (fully melting of the PCM) was found to be reduced by up to 10.4%, and the heat storage rate can be improved by up to 9.3% compared to the reference case of uniform fin sizes within the same fin volume limitations.
采用相变材料（PCM）被认为是解决能源供需不匹配问题的一种非常高效且具有成本效益的选择。高存储密度、低温度降解以及易于材料加工使PCM成为热能存储系统的关键候选材料。然而，其熔化和凝固过程中的缓慢响应速率限制了它们的应用，因此需要加入传热增强剂。本研究旨在研究圆形翅片在增强垂直三管套管中PCM热响应方面的潜在增强作用。设计并研究了尺寸不均匀且分布模式不同的翅片阵列，以确定在热交换器的各个空间区域改变翅片几何特征和分布模式的影响。对所考虑的各种翅片结构进行了参数分析，以在保持翅片材料和体积使用的相同设计限制的情况下，从瞬态熔化演变和蓄热速率的角度确定最优化的翅片结构。结果表明，与均匀翅片尺寸相比，沿热流方向改变翅片尺寸可实现更快的充电速率、更高的存储速率以及更均匀的温度分布。发现在相同翅片体积限制下，与均匀翅片尺寸的参考情况相比，将存储系统完全充电（PCM完全熔化）所需的时间最多可减少10.4%，蓄热速率最多可提高9.3%。
