| Title |
Effects of Hydrophilic Surface Treatment on Evaporation Heat Transfer at the Outside Wall of Horizontal Tubes |
| Keywords |
Hydrophilic surface treatment ; 친수성 표면처리 ; Absorption refrigerator ; 흡수식 냉동기 ; Evaporation heat transfer ; 증발열전달 ; Heat transfer coefficient ; 열전달계수 ; Horizontal tubes ; 수평관 |
| Abstract |
Evaporation heat transfer characteristics have been investigated experimentally whendistilled water is sprayed on the outside wall of horizontal tubes in a evaporator. This problem is of particular interest in the design of evaporator of an absorption system.Hydrophilic surface treatment was employed to increase the wettability on copper tubes. The results indicate that evaporation heat transfer with hydrophilic tubes is shown to be 25-44% higher than that with bare tubes at evaporation pressure of 31.8 Torr(evaporation temperature 30℃). Evaporation heat transfer rates of hydrophilic treatment tubes are improved substantially, comparing with those of conventional copper tubes in the wide range of operating parameters, such as water inlet temperatures, water mass flow rates and evaporation pressures. |