Experimental research on condensation of R134a and R404A refrigerants in tubular mini-channels during impulsive instabilities. Part II

The following paper presents the results of experimental research on the condensation of R134a and R404A refrigerants in tubular mini-channels during impulsive hydrodynamic instabilities. The first part includes an analysis of the influence of impulsive instabilities on the development of the condensation phase-change of R134a and 404A refrigerants in horizontal tubular mini-channels. The second part will present results of research on the same type of instabilities during the decay of the condensation phase-change process of R134a and 404A refrigerants. This research was conducted using the same set of investigated mini-channels with internal diameters of D = 0.63-3.30 mm. Special attention was paid to the possible occurrence of characteristic instabilities during condensation in mini-channels, so-called capillary blocking.