Refrigerant pressure drop in chevron and bumpy style flat plate heat exchangers

Adiabatic pressure drop in chevron and two styles of bumpy plate heat exchangers were investigated for vertical upward flow with R134a. Qualities ranging from sub-cooled liquid to superheated vapor were investigated. Mass fluxes ranged from 16 kg/m2 s (for superheated vapor) to approximately 300 kg/m2 s (for sub-cooled liquid). The pressure drop experiments were conducted for 10 °C and 20 °C inlet temperatures. A two-phase pressure drop model, based on the kinetic energy of the flow, was developed in order to relate the two-phase pressure drop data to the single-phase data. The model predicts two-phase pressure drop within 15% of experimental measurements.