| Title |
An Experimental Study of Flow Boiling Heat Transfer inside Small-Diameter Round Tubes |
| Keywords |
Flow boiling ; 대류비등 ; Heat transfer ; 열전달 ; Heat exchanger ; 열교환기 ; R-22 |
| Abstract |
Flow boiling heat transfer in small-diameter round tubes has been experimentally studied. The experimental apparatus consisted mainly of refrigerant pump, condenser, receiver, test section of a 1.67mm inner-diameter round tube and pre-heater for control of refrigerant quality at the inlet of test section. To investigate the effect of bubble nucleation site characteristics of different tube materials, three different tubes of copper, aluminum and brass were used. The ranges of the major experimental parameters were 5～30kW/m2 of the wall heat flux, 0.0～0.9 of the inlet vapor quality and the refrigerant mass flux was fixed at 600 kg/m2s. The experimental results showed that the flow boiling heat transfer coefficients in small tubes were affected only by heat flux, but independent of mass flux and vapor quality. The effect of tube material on flow boiling heat transfer was observed small. |