Pool boiling heat transfer characteristics of iron oxide nano-suspension under constant magnetic field

• Published in: International journal of thermal sciences Vol. 147; p. 106131
• Main Authors: Sarafraz, M.M., Pourmehran, O., Yang, B., Arjomandi, M., Ellahi, R.
• Format: Journal Article
• Language: English
• Published: Elsevier Masson SAS 01-01-2020
• Subjects: Bubble formation; Critical heat flux; Fouling mitigation; Magnetic field; Pool boiling; Bubble formation; Critical heat flux; Fouling mitigation; Magnetic field; Pool boiling
• ISSN: 1290-0729; 1778-4166
• DOI: 10.1016/j.ijthermalsci.2019.106131

In this paper, we quantified the heat transfer coefficient (HTC) of Fe3O4 aqueous nano-suspension at various mass concentrations of 0.05% 0.2%. The potential role of operating parameters including heat flux perpendicular to the surface (HF), concentration of the nanoparticle (NP), strength of magnetic field (MF), zeta potential and concentration of a specific surfactant on HTC, critical heat flux (CHF) and transient fouling resistance of the surface was identified. Results showed that MF can lower the fouling resistance providing that the nano-suspension is stable. It was shown that in this case, the HTC value was also promoted. However, the enhancement of HTC strongly depended on the zeta potential value. Likewise, by increasing the NP concentration, the CHF value was augmented, while the HTC was promoted u to wt. % = 0.15 and then decreased at wt. % = 0.2. This behavior was attributed to the existence of a thermal resistance on the surface. Notably, the bubble formation on the surface was intensified due to the MF, which was attributed to the formation of irregularities and micro-cavities due to the deposition of the NPs.
•The pool boiling heat transfer to Fe3O4/water nanofluid was conducted.•Critical heat flux and heat transfer coefficient were quantified in pool boiling.•Influence of magnetic field on boiling thermal performance was analyzed.•Bubble formation under the magnetic field was visualized.