| Title |
External Condensation Heat Transfer Coefficients of R245fa on Low Fin and Turbo-C Tubes |
| Authors |
심윤보(Yun-Bo Shim) ; 박기정(Ki-Jung Park) ; 정동수(Dongsoo Jung) |
| Keywords |
응축 열전달 ; 열전달계수 ; 26fpi 낮은 핀관 ; 터보 씨 촉진관 ; 냉매 245fa Condensation heat transfer ; Heat transfer coefficients(HTCs) ; 26fpi low fin tube ; Turbo-C enhanced tube ; R245fa |
| Abstract |
In this study, condensation heat transfer coefficients(HTCs) of R22, R123, R134a and R245fa are measured on both 26fpi low fin and Turbo-C tubes. All data are taken at the vapor temperature of 39 ℃ with a wall subcooling of 3～8 ℃. Test results show that HTCs of the newly developed low vapor pressure alternative refrigerant, R245fa, are 7.8～9.2% and 10.3～18.6% higher than those of R123 for 26fpi low fin tube and Turbo-C tube respectively. For all refrigerants tested, HTCs of Turbo-C enhanced tube are higher than those of 26fpi low fin tube. For the low fin tube, Beatty and Katz’s prediction equation yielded 20% deviation for all fluids. The heat transfer enhancement ratio of R245fa on the Turbo-C tube is 5. 9～6.4 while that of R123 is 5.7～5.9. From the view point of environmental safety and condensation heat transfer, R245fa is a long term candidate to replace R123 currently used in centrifugal chillers. |