Mechanism Of Flash In The Flow Of Refrigerant In A Capillary

Flash delay (non-equilibrium phenomenon) occurred in refrigerant flow in a capillary affects apparently the prediction accuracy of refrigerant flow rate in a capillary. “Combined nucleation” theory that accounts for both “homogeneous nucleation” and “wall nucleation” was developed, based on which, a flash flow model was established. Underpressure, an important parameter reflecting non-equilibrium phenomenon in a capillary, was obtained with this flash flow model. The simulation results agree well with the experimental data. The results show that underpressure increases with increase of the mass flow rate of refrigerant and also increases with decrease of inlet temperature.