Experimental study on nucleate boiling enhancement and bubble dynamic behavior in saturated pool boiling using a nonuniform dc electric field

Abstract

In order to investigate the effects of an electric field on the nucleate boiling heat transfer enhancement including bubble dynamic behavior, basic experiments have been performed under saturated pool boiling. In the present study, the working fluid is Freon-113 and the plate-wire electrode is used to generate a steep electric field gradient around the wire. A single-photo/high photography method is applied to measure boiling parameters. The experimental results show the shift of the boiling curve and the delay of ONE and CHF to a higher heat flux by an electric field. These EHD effects are much more considerable when the applied voltage increases. It is confirmed that the mechanisms of EHD nucleate boiling are closely connected with the dynamic behaviors of bubbles. Boiling parameters are investigated by using a high speed camera. The present results show that the boiling parameters are significantly changed by the electric field strength and nonuniformity. The relative contribution of latent heat to boiling heat transfer in an electric field is introduced. At very high voltage, the amount of latent heat transported by bubbles nearly corresponds to the total heat flux. (C) 2000 Elsevier Science Ltd. All rights reserved.