| Title |
Pool Boiling Heat Transfer Coefficients of Mixtures Containing Propane, Isobutane and HFC134a on a Plain Tube |
| Authors |
박기정(Ki-Jung Park) ; 백인철(In-Cheol Baek) ; 정동수(Dongsoo Jung) |
| Keywords |
핵비등 열전달계수 ; 대체냉매 ; 탄화수소 ; 이원 혼합냉매 ; 비등 상관식 ; 증발기 Nucleate boiling heat transfer coefficient ; Alternative refrigerant ; Hydrocarbons ; Binary mixtures ; Pool boiling correlation ; Evaporator ; |
| Abstract |
Nucleate pool boiling heat transfer coefficients(HTCs) were measured with one nonazeotropic mixture of Propane/Isobutane and two azeotropic mixtures of HFC134a/Isobutane and Propane/HFC134a. All data were taken at the liquid pool temperature of 7℃ on a horizontal plain tube with heat fluxes of 10kW/m2 to 80kW/m2 with an interval of 10kW/m2 in the decreasing order of heat flux. The measurements were made through electrical heating by a cartridge heater. The nonazeotropic mixture of Propane/Isobutane showed a reduction of HTCs as much as 41% from the ideal values. The azeotropic mixtures of HFC134a/Isobutane and Propane/HFC134a showed a reduction of HTCs as much as 44% from the ideal values at compositions other than azeotropic compositions. At azeotropic compositions, however, the HTCs were even higher than the ideal values due to the increase in the vapor pressure. For all mixtures, the reduction in heat transfer was greater with a larger gliding temperature difference. Stephan and Ko?rner's and Jung et al's correlations predicted the HTCs of mixtures with a mean deviation of 11%. The largest mean deviation occurred at the azeotropic compositions of HFC134a/Isobutane and Propane/HFC134a. |