Experimental study of condensation heat transfer in a condenser with a liquid-vapor separator

Abstract

The condensation heat transfer and the separation efficiency of R134a in a condenser with a liquid-vapor separator were studied experimentally. The condenser had 33 parallel horizontal rectangular channels each100 mm long and 1.5 mm in hydraulic diameter divided into three channel passes. The liquid-vapor separator was a 2 mm diameter U-type tube installed at the junction between the first and second channel passes. The experiments used a saturation temperature of 25 °C with refrigerant mass fluxes of 74–212 kg/m2 s and cooling water mass fluxes of 25–250 kg/m2 s. The results showed that the condensation in the second channel pass was influenced by the liquid-vapor separator in the outlet of the first channel pass with the inlet vapor quality improved significantly by the removal of the condensate from the first channel pass. The heat transfer coefficient in the second channel pass was increased by 20% to 40% with the overall heat transfer coefficient in the condenser with the liquid-vapor separator improved by 10% to 20%. Increasing the cooling water mass flow rate slightly increased the condensate separation rate, but the separation ratio decreased. Both the amount of separated condensate and the separation ratio increased with increasing vapor mass flux. The condensate separation capacity was limited by the liquid-vapor separator tube diameter.