A Method for Improving Critical Heat Flux

BACKGROUND

Boiling is a phenomenon of vital importance in a broad range of industries such as power generation, desalination, chemical processing, refrigeration, and electronics thermal management. Nucleate boiling is an efficient way of transferring heat, for a given difference between the heat transfer surface and the fluid temperatures (the so-called wall superheat). Unfortunately, Boiling Crisis occurs when a vapor layer forms on a heating surface resulting in orders of magnitude reduction in the rate of boiling. This requires additional energy inputs to achieve boiling which can be detrimental (up to catastrophic failure) to a vessel and power consumption.

SUMMARY OF TECHNOLOGY

OSU research has developed a simple, novel, and very efficient method to prevent boiling crisis by physically separating and engineering the heating and boiling surfaces. The method significantly improves the critical heat flux and reduces the wall superheating required to achieve bubble nucleation and boiling. Shown as a simplified embodiment in Figure 1 while heat can be applied to standard vessel with this method the vessel is protected using a liquid-philic coating (in yellow) and includes separate liquid-phobic boiling focus-point(s) (in blue) to prevent boiling crisis thus separating the heating surface from the boiling surface. By reducing or eliminating the vapor layer at the heat transfer surface and using liquid-phobic coatings at the boiling focus point(s), the required energy to achieve boiling is greatly reduced. So much so the system can be run using solar energy. 

 Figure 1: Simplified Setup