EXPERIMENTAL VALIDATION OF A CAPPILARY TUBE SIMULATION MODEL WITH REFRIGERANT MIXTURES FLOW

Abstract

This paper presents the experimental validation of a simulation model for
refrigerant mixtures flow through capillary tubes. To perform such
validation it was built an experimental apparatus using a blow-down
process. It was carried out preliminary tests for characterization of
experimental parameters: actual capillary tube diameters; relative
roughness; and the heat losses in subcooling/quality control system. It
was obtained almost 200 experimental points for R-407C (a zeotropic
mixture) and R-410A (a near azeotropic mixture). Complete data set for
each point consists of the measured pressure and temperature profiles,
mass flow rate and mixture composition, as well as subcooling/quality
control system inlet and outlet temperatures and heater electric power
consumption for tests with two-phase flow capillary tube inlet conditions.
Comparison of simulation and experimental data show a good agreement.
Main deviations are connected with the delay of vaporization
phenomenon occurrence, experimentally verified by the authors.