| Title |
Experimental Study on Condensation Heat Transfer Characteristics of Special Heat Transfer Tubes |
| Keywords |
Thermal resistance ; 열저항 ; Enhancement ratio ; 열전달 촉진비 ; Low integral-fin tubes ; 낮은 핀관 ; Condensation heat transfer ; 응축열전달 |
| Abstract |
In this study, condensation heat transfer characteristics were conducted with special heat transfer tubes of SH-C type. Experiments were carried out the saturated vapor temperature of 334 K and the wall subcooling of 1.5∼4.5 K. The refrigerant was R-113 and the enhanced tubes used in the present study were SH-CDR, SH-CYR and SH-CHR. The experimental results showed that the condensation heat transfer coefficients of SH-C type tubes were about 23∼66% higher than those of a low integral-fin tube. It was visualized that the condensed liquid on the outer surface of SH-C type tubes flowed continuously down unlike a low integral-fin tube and a plain tube, due to a 3-D extending fin on the outer surface of SH-C type tubes. As a result, the thermal resistance of the condensed liquid decreased and the heat transfer coefficient increased. Also, the enhancement ratio of SH-CDR tube was the highest, and it was about 9∼11 times as compared to that of a plain tube. |