摘要
Alternative refrigerant R-134a is considered to be ozone-friendly and apotential candidate for replacing the refrigerant R-12 in refrigeration and air-conditioningapplications. This paper presents an experimental investigation on condensation heat transfer of thealternative refrigerant R-134a flowing inside a helicoidal pipe with the cooling water flowingthrough the annular helicoidal passage in a counter-flow direction. The heat transfer experimentswere performed for R-134a mass flow flux ranging from 100 to 420 kg/m^2 s with the superheat of theinlet vapor of 2. 8℃ and 8.3℃, respectively. The average Nusselt numbers were experimentallydetermined for a helicoidal pipe with the helix axis of vertical direction. In addition, theobtained experimental results were compared with the results for R-134a condensation in straight andhelicoidal pipes available in the open literature.
Alternative refrigerant R-134a is considered to be ozone-friendly and apotential candidate for replacing the refrigerant R-12 in refrigeration and air-conditioningapplications. This paper presents an experimental investigation on condensation heat transfer of thealternative refrigerant R-134a flowing inside a helicoidal pipe with the cooling water flowingthrough the annular helicoidal passage in a counter-flow direction. The heat transfer experimentswere performed for R-134a mass flow flux ranging from 100 to 420 kg/m^2 s with the superheat of theinlet vapor of 2. 8℃ and 8.3℃, respectively. The average Nusselt numbers were experimentallydetermined for a helicoidal pipe with the helix axis of vertical direction. In addition, theobtained experimental results were compared with the results for R-134a condensation in straight andhelicoidal pipes available in the open literature.
基金
ProjectsupportedbytheNationalNaturalScienceFoundationofChina.(GrantNo :5 0 376 0 30 )
