Condensation of refrigerant R404A under external disturbances

The paper describes results of experimental investigations of condensation of the refrigerant R404A in the flow through a coiled tube under conditions of external disturbances that occur in refrigeration units. The development and decay of condensation is induced by impulse changes of parameters of the two-phase system, such as pressure and mass flux density in the tubular channel. It is confirmed that the two-phase systems exhibit wave properties and that the disturbances propagate with finite velocities. Experiment-based correlations are obtained to describe the propagation of disturbances during development and decay of condensation of the refrigeration medium in the tubular channel.