Photographic study of bubble departure diameter in saturated pool boiling to electrolyte solutions

Steady State Vapor Bubble in Pool Boiling

Boiling, a dynamic and multiscale process, has been studied for several decades; however, a comprehensive understanding of the process is still lacking. The bubble ebullition cycle, which occurs over millisecond time-span, makes it extremely challenging to study near-surface interfacial characteristics of a single bubble. Here, we create a steady-state vapor bubble that can remain stable for ho...

Pool Boiling Heat Transfer in Water/Amines Solutions

In this investigation, nucleate boiling heat transfer coefficients were experimentally measured during pool boiling of mixtures, consisting of water/monoethanolamine and water/diethanolamine on a horizontal heating rod, under atmospheric pressure. The experiment was carried out below 205 kW.m-2 heat flux, over a wide range of concentrations. These experiments include, measurement of pool boilin...

Prediction of bubble departure in forced convection boiling: A mechanistic

Flow Boiling on Micropin Fins Entrenched Inside a Microchannel—Flow Patterns and Bubble Departure Diameter and Bubble Frequency

Flow boiling of HFE 7000 in five parallel microchannels of 222 m hydraulic diameter, each containing a single row of 24 in-line 100 m pin fins, was investigated. High speed photography revealed the dominant flow patterns, namely, the bubbly flow, the multiple flow, and the wavy-annular flow. The interaction of the bubble with the pin fins during nucleate boiling from G 350 kg /m2 s to G 827 kg ...

Mechanism and Prevention of Scale Formation in Boilers

Nucleate boiling heat transfer coefficients may be strongly reduced by scale formation, even for conditions where the bulk foulant concentration is well below the saturation concentration. Due to the mechanism of micro-layer evaporation, the local concentration at the heat transfer surface can be considerably increased, causing the formation of scale and changes in bubble frequency and bubble d...