| Title |
Characteristics on Evaporating Heat Transfer and Pressure Drop of HCs Refrigerants |
| Keywords |
Heat transfer coefficient ; 열전달계수 ; Hydrocarbon ; 탄화수소 ; Pressure drop ; 압력강하 ; Natural refrigerant ; 자연냉매 ; Evaporator ; 증발기 |
| Abstract |
Experimental results for heat transfer characteristic and pressure gradients of HCs refrigerants R-290, R-600a, R-1270 and HCFC refrigerant R-22 during evaporating inside horizontal double pipe heat exchangers are presented. The test sections which has one tube diameter of 12.70mm with 0.86mm wall thickness, another tube diameter of 9.52mm with 0.76mm wall thickness are used for this investigation. The local evaporating heat transfer coefficients of hydrocarbon refrigerants were higher than that of R-22. The average evaporating heat transfer coefficient increased with the increase of the mass flux. It showed the higher values in hydrocarbon refrigerants than R-22. Hydrocarbon refrigerants have higher pressure drop than R-22 in 12.7mm and 9.52mm. This results form the investigation can be used in the design of heat transfer exchangers using hydrocarbons as the refrigerant for the air-conditioning systems. |