Phase separation of two-phase ammonia in horizontal T-junction at low mass velocity

Phase separation of a two-phase working fluid accompanies the thermal-hydraulic process in every system and device, with at least one T-junction used in a two-phase line. Adequate qualitative and quantitative prediction of phase separation in T-junction is critical for successful designing, e.g., refrigeration, thermal control, and fluid transport systems. Three simple T-junctions with different inlet and side diameters were tested in the horizontal position on two-phase ammonia at a saturation level of 40 divided by 60 degrees C and mass velocities of 25 divided by 150 kg center dot m(-2)s(-1). Based on test data, it has been revealed that at the relative side branch mass flow rate above 0.6, the phase separation behaviour does not depend on inlet mass velocity, vapour quality, void fraction, flow patterns (stratified, slug and annular) and relative side branch diameter. A simplified empirical correlation has been proposed describing the ammonia test points with an error margin of +/- 15%.

Automated summary

Phase separation occurs in every system and device with a T-junction used in a two-phase line, making it crucial to predict it accurately for successful designing of refrigeration, thermal control, and fluid transport systems. Testing was conducted on three simple T-junctions with different inlet and side diameters, using two-phase ammonia at a saturation level of 40/60 degrees C and mass velocities of 25/150 kg·m(-2)·s(-1). Based on the test data, it was found that the phase separation behavior is independent of inlet mass velocity, vapor quality, void fraction, flow patterns, and relative side branch diameter when the relative side branch mass flow rate exceeds 0.6. A simplified empirical correlation was proposed with an error margin of +/- 15% to describe the ammonia test points.