Hernaiz Marta, Elexpe Iker, Aranzabe Estibaliz, Aguayo Andrés T
TEKNIKER Basque Research and Technology Alliance (BRTA), C/Iñaki Goenaga, 5, 20600 Eibar, Spain.
Department of Chemical Engineering, University of the Basque Country (UPV/EHU), Apdo. 644, 48080 Bilbao, Spain.
Nanomaterials (Basel). 2023 Aug 1;13(15):2230. doi: 10.3390/nano13152230.
Flow boiling is a complex process but very efficient for thermal management in different sectors; enhancing flow boiling heat transfer properties is a research field of great interest. This study proposes the use of various nanomaterials, carbon-based materials, and metal oxides; in n-pentane as a hydrocarbon-based refrigerant to enhance the flow boiling heat transfer coefficient. This thermal property has been experimentally evaluated using a vertical evaporation device of glass with an internal diameter of 20 mm. The results have shown that proposed nanomaterials dispersion in n-pentane has a limited effect on the thermophysical properties and is conditioned by their dispersibility but promotes a significant increment of pentane heat transfer coefficient (h), increasing the overall heat transfer coefficient (U) of the evaporator. The enhanced heat transfer performance is attributed to the behavior of nanoparticles under working conditions and their interaction with the working surface, promoting a higher generation of nucleation sites. The observed behavior suggests a heat transfer mechanism transition from forced convection to nucleate heat transfer, supported by visual observations.
流动沸腾是一个复杂的过程，但在不同领域的热管理中非常高效；增强流动沸腾传热特性是一个备受关注的研究领域。本研究提出使用各种纳米材料、碳基材料和金属氧化物；以正戊烷作为碳氢化合物基制冷剂来提高流动沸腾传热系数。已使用内径为20毫米的玻璃垂直蒸发装置对这种热性能进行了实验评估。结果表明，所提出的纳米材料在正戊烷中的分散对热物理性质的影响有限，并且受其分散性的制约，但促进了戊烷传热系数（h）的显著增加，提高了蒸发器的总传热系数（U）。增强的传热性能归因于纳米颗粒在工作条件下的行为及其与工作表面的相互作用，促进了更多成核位点的产生。观察到的行为表明传热机制从强制对流转变为核态传热，这得到了可视化观察的支持。
