| Title |
Condensation Heat Transfer Coefficients of R245fa on a Plain Tube |
| Authors |
심윤보(Yun-Bo Shim) ; 박기정(Ki-Jung Park) ; 정동수(Dongsoo Jung) ; 김종성(Jong-Seong Kim) |
| Keywords |
응축 열전달 ; 열전달계수 ; 냉매 R245fa ; 오존층 붕괴 Condensation heat transfer ; Heat transfer coefficients(HTCs) ; R245fa ; Ozone layer depletion |
| Abstract |
In this study, condensation heat transfer coefficients (HTCs) of R22, R134a, R245fa and R123 are measured on a horizontal plain tube. All data are taken at the vapor temperature of 39℃ with a wall subcooling temperature 3-8℃. Test results show the HTCs of newly developed alternative low vapor pressure refrigerant, R245fa, on a plain tube are 9.5% higher than those of R123 while they are 3.3% and 5.6% lower than those of R134a and R22 respectively. Nusselt’s prediction equation for a plain tube underpredicts the data by 13.7% for all refrigerants while a modified equation yielded 5.9% deviation against all data. From the view point of environmental safety and condensation heat transfer, R245fa is a long term good candidate to replace R123 used in centrifugal chillers. |