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Effect of Dissolved Gasses on Spray Evaporative Cooling With Water.


pdf icon Effect of Dissolved Gasses on Spray Evaporative Cooling With Water. (722 K)
Tinker, S. C.; diMarzo, M.

NIST GCR 96-687; Paper 16; June 1996.

Sponsor:

National Institute of Standards and Technology, Gaithersburg, MD

Available from:

National Technical Information Service
Order number: PB96-202304

Keywords:

water sprays; evaporative cooling; water; solid surfaces; droplets; hot surfaces; drop sizes; size distributions; experiments; data processing

Abstract:

An experimental investigation of the effect of non-degassed water used to cool a solid surface is presented. The solid surface is subjected to thermal radiant input from three panels positioned above it. The water is deposited on the surface in the form of a sparse spray with droplets of about 10 ml. Previous experiments with degassed water are compared with these new experiments and the effect of dissolved gasses is quantified in terms of the overall transient thermal behavior of the solid. A lower steady-state average temperature is achieved when gasses are not removed from the water. This result suggests that the configuration of the liquid droplets on the surface is different and that the radiant heat input into the droplet is altered by the gas bubbles present in the deposited droplet. This information provides guidance in practical applications such as sprinkler suppression systems where water damages are a concern.