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. •A new liquid–vapor separation microchannel condenser (LSMC) is presented.•Pressure drop of LSMC is half of parallel flow microchannel condenser (PFMC).•Heat transfer coefficient of LSMC exceeds PFMC at high mass flux and quality.•The LSMC shows an excellent combined thermodynamic performance than the PFMC.