Boiling Heat Transfer Surface Capable of Transient Heating and Nucleation Control

Using MEMS technique, we develop a novel boiling heat transfer surface with three types of circuits: a heater, a bubbling trigger, and thermocouples. This paper presents the design of the heat transfer surface and experimental results of bubbling behavior on this surface during highly subcooled boiling at high heat flux. The heater makes superheated liquid layer transiently. Then the bubbling trigger make a tiny hydrogen bubble playing a role of a nuclei of a boiling bubble. The thermocouple signal reveals a growth of superheated liquid layer, vaporization of the liquid layer beneath the bubble, and rewetting. It has been known that highly subcooled boiling at high heat flux results in atomization of vapor bubbles on heat transfer surfaces due to the violent condensation. Parametric experiments were conducted to clarify the occurrence condition of the atomization by changing heat flux and heating time before nucleation. Bubbling behavior was categorized into four patterns: Oscillating, Not-Oscillating, Single-bubble emission, and Multi-bubbles emission.