Berce Jure, Hadžić Armin, Može Matic, Arhar Klara, Gjerkeš Henrik, Zupančič Matevž, Golobič Iztok
Faculty of Mechanical Engineering, University of Ljubljana, Aškerčeva 6, 1000 Ljubljana, Slovenia.
School of Engineering and Management, University of Nova Gorica, Vipavska 13, 5000 Nova Gorica, Slovenia.
Nanomaterials (Basel). 2024 Feb 4;14(3):311. doi: 10.3390/nano14030311.
Prior studies have evidenced the potential for enhancing boiling heat transfer through modifications of surface or fluid properties. The deployment of nanofluids in pool boiling systems is challenging due to the deposition of nanoparticles on structured surfaces, which may result in performance deterioration. This study addresses the use of TiO-water nanofluids (mass concentrations of 0.001 wt.% and 0.1 wt.%) in pool boiling heat transfer and concurrent mitigation of nanoparticle deposition on superhydrophobic laser-textured copper surfaces. Samples, modified through nanosecond laser texturing, were subjected to boiling in an as-prepared superhydrophilic (SHPI) state and in a superhydrophobic state (SHPO) following hydrophobization with a self-assembled monolayer of fluorinated silane. The boiling performance assessment involved five consecutive boiling curve runs under saturated conditions at atmospheric pressure. Results on superhydrophilic surfaces reveal that the use of nanofluids always led to a deterioration of the heat transfer coefficient (up to 90%) compared to pure water due to high nanoparticle deposition. The latter was largely mitigated on superhydrophobic surfaces, yet their performance was still inferior to that of the same surface in water. On the other hand, CHF values of 1209 kW m and 1462 kW m were recorded at 0.1 wt.% concentration on both superhydrophobic and superhydrophilic surfaces, respectively, representing a slight enhancement of 16% and 27% compared to the results obtained on their counterparts investigated in water.
先前的研究已经证明，通过改变表面或流体特性来强化沸腾传热具有潜力。在池沸腾系统中使用纳米流体具有挑战性，因为纳米颗粒会沉积在结构化表面上，这可能导致性能下降。本研究探讨了TiO-水纳米流体（质量浓度分别为0.001 wt.%和0.1 wt.%）在池沸腾传热中的应用，以及同时减轻纳米颗粒在超疏水激光纹理化铜表面上的沉积。通过纳秒激光纹理化改性的样品，在制备后的超亲水（SHPI）状态下以及在用氟化硅烷自组装单层进行疏水化处理后的超疏水状态（SHPO）下进行沸腾实验。沸腾性能评估包括在大气压饱和条件下连续进行五次沸腾曲线测试。超亲水表面的结果表明，由于纳米颗粒的高沉积，与纯水相比，使用纳米流体总是导致传热系数下降（高达90%）。在超疏水表面上，纳米颗粒沉积在很大程度上得到缓解，但其性能仍低于在水中相同表面的性能。另一方面，在超疏水和超亲水表面上，0.1 wt.%浓度下的临界热流密度（CHF）值分别记录为1209 kW/m²和1462 kW/m²，与在水中研究的对应表面相比，分别略有提高16%和27%。
