The cause of a reduced plant performance in vapour-compression plants is the substitution of working fluids. Therefore, extremely accurate design procedures are needed, because the relative sizing of each plant-component is essential for the cycle performance. For this reason, the knowledge of the heat transfer characteristics of new fluids in condensers and evaporators is mandatory. The heat transfer characteristics of the near-zeotropic mixtures: R410A, R404A and the zeotropic mixtures: R407C and R417A were experimentally investigated and analyzed as a function of evaporating pressure, heat and mass flux. The test section was a smooth, horizontal, stainless steel tube (6.0 mm I.D:, 6.00 m length) uniformly heated by the Joule effect. The working parameters were varied within the following ranges: evaporating pressure 360 to 1200 kPa, heat flux 9.0 to 30.0 kW m-2 at an almost costant refrigerant mass flux of 350 kg m -2 s-1.
Flow Boiling Heat Transfer with HFC Mixtures in a Smooth Horizontal Tube
DE ROSSI F;
2005-01-01
Abstract
The cause of a reduced plant performance in vapour-compression plants is the substitution of working fluids. Therefore, extremely accurate design procedures are needed, because the relative sizing of each plant-component is essential for the cycle performance. For this reason, the knowledge of the heat transfer characteristics of new fluids in condensers and evaporators is mandatory. The heat transfer characteristics of the near-zeotropic mixtures: R410A, R404A and the zeotropic mixtures: R407C and R417A were experimentally investigated and analyzed as a function of evaporating pressure, heat and mass flux. The test section was a smooth, horizontal, stainless steel tube (6.0 mm I.D:, 6.00 m length) uniformly heated by the Joule effect. The working parameters were varied within the following ranges: evaporating pressure 360 to 1200 kPa, heat flux 9.0 to 30.0 kW m-2 at an almost costant refrigerant mass flux of 350 kg m -2 s-1.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
