Boiling heat transfer characteristics in water spray cooling on hot steel plate

Abstract

Water spray cooling has been widely used in a great number of engineering applications, especially in hot steel plate cooling like as an accelerated cooling of plate mills. The boiling heat transfer characteristics during water spray cooling were investigated by simultaneous boiling visualization and heat transfer measurement. The hot steel plate was uniformly heated up to 900°C and was cooled down during the water spray cooling. The local surface temperature, heat flux and heat transfer coefficient on the hot steel plate was determined by solving 2-dimensional inverse heat conduction with the flat-plate type heat flux gauge. The boiling visualization shows when the nucleate boiling starts to occur and turns to collapse the film boiling on the hot surface. The measured onset of nucleate boiling agrees well with the corresponding boiling visualization. The cooling uniformity on the hot steel plate can be controlled by spray nozzle height. So the present study can be helpful to understand the boiling heat transfer mechanism during water spray cooling. © 2016, ThermoMechanical Processing (TMP). All rights reserved.