Design of an R-134a Loop for Subcritical and Supercritical Forced-Convection Heat Transfer Studies

Abstract

The R-134a test loop is a forced-flow experimental facility for the study of heat transfer properties of R-134a under subcritical and supercritical thermodynamic conditions. The loop is designed to operate with pressures as high as 6 MPa and temperatures up to 140 °C. The intended mass flux is in the range of 500-6000 kg/m2s for the experiments with subcritical thermodynamic states and 500-4000kg/m2s for supercritical conditions. The loop has been designed to accommodate a variety of test-section geometries, ranging from a straight circular tube to a 7-rod bundle, achieving heat fluxes up to 2.5 MW/m2 depending on the test section geometry. The design of the loop allows for easy reconfiguration of the test-section orientation relative to the gravitational direction and adjustment to the length of the test section.