Nucleate Boiling Heat transfer From an Enhanced Horizontal Tube Using Different Working Liquids

Abstract

In this research, an experimental investigation of nucleate pool boiling froma single horizontal tube has been done ,with distilled water and ethanol as working liquids.The tests were carried out on five tubes;one of them has smooth external surface wherethe other four tubes have enhanced external surfaces of different finish with outer diameter (30 mm( and length (71mm) under atmospheric pressure within the range of heat flux(14.94–67.25kW/m2). The effect of the liquid on the characteristics of boiling and amount of enhancement of enhanced tubeswere studied. The results showed that the enhancement factor of all tubes has maximum value with distilled water as boiling liquid equal to (2.11).Where with ethanol, the maximum value was equal to (1.84) .The comparison between results of smooth tube in the present work and results of (Rohsenowcorrelation ) showed a good agreement.