Enhanced boiling of saturated water on copper coated heating tubes

摘要

This paper pertains to an experimental investigation on nucleate pool boiling of saturated water from uncoated as well as copper coated mild steel heating tubes of thicknesses 19,26,33,41 and 60 mu m at atmospheric and subatmospheric pressures.It also includes the effect of heat flux,pressure and coating thickness on boiling heat transfer coefficient on coated tube surfaces.Heat transfer coefficient for saturated boiling of water on uncoated tube as well as on copper coated tubes at atmospheric and subatmospheric pressures increases with the increase in heat flux and pressure.Further,coating on plain tube enhances the value of heat transfer coefficient at atmospheric and subatmospheric pressures,enhancement continue up to a certain value of coating thickness and thereafter decreases with increase in thickness of coating.A criterion for enhanced boiling of water on copper coated tubes has also been prescribed in this paper.