Transient cooling by a liquid spray of a surface heated above the boiling temperature: Experimental investigation

Abstract

This investigation deals with the feasibility of quick cooling of hot surfaces by means of a water jet. The temperatures of the hot surfaces are above boiling in the region of partial nucleate boiling with an unstable film. Experiments were performed in which a heated pipe was sprayed with a water jet on its inner surface. The quantities of water were 50, 100, and 150 Liters per square meter. The wall temperatures were measured and the heat flux was obtained. The results are presented as a function of the pipe wall temperatures, which were in the range of 110°C to 220°C. Heat convection coefficients were also calculated, and values as high as 150 kilowats per square meter per degree Kelvin were obtained. The active parts of the phenomena, i.e., those parts in which boiling took place, were transient and their duration never exceeded one second.