Experimental investigation on two-phase frictional pressure drop of R600a and R600a/3GS oil mixture in a smooth horizontal tube

摘要

The current work demonstrates an empirical investigation on the two-phase flow frictional pressure drops attributes of the R600a/3GS oil within an inner diameter horizontal tube, sized 8 mm. Furthermore, experiments were carried out at the nominal oil concentrations between 0% and 4% at the saturation temperature of 20 degrees C, having the heat flux amounting to 10.0 kW.m(-2), together with the mass flux that ranged between 150 and 300 kg.m(-2).s(-1). Moreover, the impact of the nominal oil concentration, together with the mass flux and quality on the frictional pressure drops were not only investigated but also debated. As the findings indicate, the existence of oil augments the two-phase frictional pressure drop approximately between 0 and 60% with the present test conditions. Meanwhile, the comparison of the experimental data of the two-phase frictional pressure drops was carried out with some of the relationships present in literatures. The result showed the fact that the experimental data reasonably agree with the correlation of Schlager, with 95% of the empirical points being in an error bandwidth amounting to +/- 25%. Besides that, a new correlation for predicting the frictional pressure drop of R600a/oil mixture was modified on the basis of the local attributes of the oil. In accordance with the forecasted values from the modified correlation, there is an acceptable agreement with the empirical data. Moreover, the deviations are located within -20%-+15%. Accordingly, it could be put to use for predicting the frictional pressure drops of R600a/oil mixture in evaporator while designing a refrigeration system. (C) 2020 Elsevier Ltd and IIR. All rights reserved.