Implementing active vapor-liquid adjustment during phase change processes can enhance the heat transfer coefficient (h) and decrease the pressure drop (Δp) simultaneously. In this study

the current status of vapor-liquid adjustment principles

vapor-liquid adjustment units

and heat exchangers are comprehensively reviewed. The objective of active vapor-liquid adjustment is to adjust the vapor quality to extend the highly efficient heat transfer region during condensation (liquid-separation condensation) and evaporation (liquid adjustment evaporation) processes; however

the targeted vapor qualities are different. The vapor-liquid adjustment units

namely

the orifice-baffle header

T-junction header

and header with mesh-pore structure

are considered. It was observed that the liquid drainage ratio (FL) of the orifice-baffle and T-junction headers can be up to 100% at a low inlet mass flow rate

but only 30% in headers with mesh-pore structures. The HTC of liquid-separation condensers can be increased by up to 112% compared to conventional condensers. However

the application of vapor- liquid adjustment during evaporation is limited

and its mechanisms require further investigation. The performance of vapor-liquid adjusting heat exchangers is highly correlated to the vapor-liquid separation efficiency (η) and distributions of the vapor quality and mass flow rate in the branches. Based on the co-simulation method that adds the flow pattern factors in the header (bubble

liquid film

and droplet)

the mass transfer between the vapor and liquid interface and branch pressure drop improves the model accuracy of the vapor-liquid adjusting heat exchanger.