Nucleate boiling of dilute nanofluids – Mechanism exploring and modeling

• Mechanistic analysis of the common findings by nanofluid boiling experiments.
• Applicability of the heat flux partitioning model to nanofluids.
• Preliminary model development based on the heat flux partitioning model.
• Suggestions for future work.

Despite the overall merits of using nanofluids as heat transfer fluids are still under controversy in many fields, their application in nuclear reactor systems, especially the IVR system has been proved to be promising. However, the lack of fundamental understanding of the physical mechanisms has hindered the applications. For the purpose of developing a mechanistic model of nucleate boiling of nanofluids for nuclear applications, the common findings yielded from most experimental investigations available in the literature are analyzed in this study. It was demonstrated that the heater surface modification induced by nanoparticle deposition during the boiling process is the major cause of the dramatic boiling heat transfer performance of nanofluids. It was further suggested that the classic heat partitioning model is applicable to predicting nucleate boiling of nanofluids on condition that the surface modification and the nucleate boiling parameters (e.g. the active site density, the bubble departure diameter and frequency) are properly formulated.