Abstract:
This experimental work studies the distribution of a two-phase
refrigerant flow over a horizontal impacting T-junction. A setup
was built which consists of two parts: a flow conditioner and
a test section. The flow conditioner creates a two-phase mixtures
(R32) at a saturation temperature between 10 C and 20 C
with a mass flux of 150 to 700 kg=(m2 s) and a vapour quality
between 0 and 1. In the test section, the two-phase flow is
distributed over two identical parallel sections using an impacting
T-junction. The backpressure and heat input of each parallel
section can be regulated. The mass flow rates and vapour qualities
are measured before and after the T-junction. Further, the
pressure gradient over the T-junction is measured and the void
fraction is determined before the T-junction using a capacitive
void fraction sensor. Using design of experiments, the main effects
of superficial vapour velocity, superficial liquid velocity and
saturation pressure on the distribution of R32 were studied. For
R32, the two phases only distribute uniformly over the T-junction
when the mass flow rate through the two outlet branches is equal.
Further, the experiments show a decreased tendency of the liquid
to exit through the outlet with the lowest mass flow rate with increasing
vapour superficial velocity. The influence of the superficial
liquid velocity was less pronounced and dependent on the
superficial vapour velocity. Finally, no effect of the saturation
pressure was found. The obtained results were then compared
with the results of water-air mixtures found in literature.
Description:
Papers presented at the 13th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Portoroz, Slovenia on 17-19 July 2017 .
