Sie können Bookmarks mittels Listen verwalten, loggen Sie sich dafür bitte in Ihr SLUB Benutzerkonto ein.
Medientyp:
E-Book
Titel:
Boiling Heat Transfer Performance of Loop Thermosyphon on Super-Hydrophilic Aluminum Surfaces Fabricated Via Laser Interference Surface Structuring
Beschreibung:
Due to the recent advances in the manufacturing of electronic devices, efficient cooling and heat dissipation systems are required to achieve high technological performance. In this regard, several studies have been focused on improving boiling heat transfer using laser-fabricated surfaces; however, these studies have failed to consider practical conditions comprehensively and elucidate the influence of the laser-fabricated surfaces on the boiling heat transfer. To address this deficiency in the literature, this paper presents the experimentally obtained boiling heat transfer performance of a gravity-driven loop thermosyphon using super-hydrophilic aluminum surfaces fabricated via laser interference surface structuring (LISS). Untreated and line- and grid-grooved surfaces fabricated via LISS with different configurations were tested using R1234ze(E) as the working fluid. In comparison with the untreated surface, the grid-grooved LISS-fabricated surfaces exhibited significant enhancements in the boiling heat transfer coefficients due to the agglomerated groove structures, leading to a lower superheating temperature. A maximum heat transfer coefficient of 82.3 kWm−2K−1 and maximum improvement of 195% were achieved with the LISS240a surface, as compared with the bare surface, at a chip heat flux of 750 kWm−2. In addition, the highest critical heat flux (CHF) of 1057 kWm−2, which corresponds to an enhancement of 194% when compared with the values calculated using the Zuber correlation, was obtained for the LISS5-fabricated surface. Furthermore, analyses of the heat transfer mechanisms in the presence of the microgroove surfaces were conducted. Finally, a CHF correlation was developed to characterize the super-hydrophilic surfaces with groove structures in the thermosyphon by incorporating the effects of the liquid–vapor interfacial resistance in the microgrooves. The CHF thus predicted agreed well with that determined based on the experiments