Experimental Study on Visualized Pool Boiling Heat Transfer Characteristics of Machined Copper Surface
Under normal atmospheric pressure,a visual pool boiling experiment was conducted on a self-designed and manufactured experimental platform using copper rods with different roughness copper based surfaces obtained through mechanical processing.Advanced cameras were used to record the boiling process of bubble generation,growth,and detachment on the copper based surface,while data collectors were used to record the temperature at different nodes of the copper rod.The heat transfer characteristics between smooth surface and machined surface with different roughness degree are obtained through com-parative analysis.It is found that at low heat flux,the smooth surface begins to boil first,followed by the relatively wide threaded groove surface.At a high heat flux,the copper surface with a groove width of 0.3 mm had the fastest bubble detachment frequency and the best heat transfer effect.The copper surface with a groove width of 0.1 mm had a larger bubble detachment frequency and a slower one.However,overall comparison showed that the bubble detachment frequency after mechanical treatment was stronger than that of the smooth surface without processing.Finally,the influence trend of different surfaces on the criti-cal heat flux and heat transfer coefficient is sorted out by processing the laboratory data.
machined surfacepool boilingheat fluxheat transfer coefficient