NUCLEATE POOL BOILING IN A CONFINED SPACE

Abstract

Nucleate pool boiling of pure water and dilute aqueous sodium lauryl sulfate (SLS) solutions within a confined space between heated and unheated horizontal-parallel surfaces has been investigated under atmospheric pressure. The electrically heated lower surface is made of a sheet of stainless steel 304 with the dimension of 145 × 22 × 0.05 mm and the unheated upper plate is a stainless steel cylinder with a diameter of 20 mm. Periphery of the confined space is open and the size of the gap can be varied from 0 to 10 mm. Experimental results show that with the size of the gap between 0.3 and 3 mm, the heat transfer coefficient may increase to as much as 200 percent of those measured for conventional pool boiling. The addition of surfactant has no significant influence on the heat transfer coefficient in this case. Based on the experimental results, the microlayer evaporation with fluid flow driven by the gradient of disjoining pressure is discussed and considered as an important heat transfer mechanism for nucleate pool boiling in confined spaces

KEYWORDS:

• Nucleate boiling
• Confined space
• Disjoining pressure
• Microlayer evaporation

Additional information

Notes on contributors

YU MIN YANG

The author to whom correspondence should be addressed.