Experimental investigation on microchannel condensers with and without liquid-vapor separation headers

To enhance heat transfer in microchannels during condensation by improving the refrigerant average quality, a new liquid-vapor separation microchannel condenser (LSMC) is presented in this paper. Compared with the common parallel flow microchannel condenser (PFMC), the LSMC has a pair of headers that can drain away the condensate after each pass. The in-tube heat transfer coefficient and pressure drop of the two kinds of microchannel condensers with similar heat transfer areas are compared under mass fluxes that range from 450 kg/(m2s) to 770 kg/(m2s), heat fluxes that range from 1.5 kW/m2 to 2.45 kW/m2, and condensing temperatures that range from 45 °C to 50 °C. Results show that the average heat transfer coefficient (AHTC) of the LSMC exceeds that of the PFMC when the mass flux is more than 590 kg/(m2s) or the average quality is more than 0.57. The pressure drop of the LSMC greatly reduces by 30.5%-52.6% of the PFMC. The combined thermodynamic performance of the LSMC is better than that of the PFMC based on the ranking through the penalty factor and minimum entropy generation number.