Numerical simulation on constituents separation of R134a/R600a in a horizontal T-junction

Abstract

Abstract T-junction, which is regarded as an effective solution to phase separation of air-water, has already been widely applied in industry sector, especially in thermodynamic cycles for improving cycle performance. However, the research on constituent separation of organic refrigerants in the T-junction is just emerging without clear understanding on mechanism, variation and application. In this paper, the constituent separation performance of organic refrigerants, R134a/R600a, in horizontal branch T-junctions is numerically investigated. The computations are conducted based on the Eulerian method with the k-e turbulence model, which has been used to predict phase separation and an agreement is concluded. The inlet mass flux and qualities are 200 kg·m−2·s−1 and from 0.1 to 0.4, respectively. Based on the model, detailed phase and constituent distribution in T-junction are obtained and then discussed. Furthermore, the separation efficiencies of R134a are analysed based on calculation results. The results show that an agreement is observed on the separation efficiency with the inlet quality varying from 0.123 to 0.286 by comparing with the experimental results. When the inlet quality is 0.4, the inconsistency between the simulation results and the theoretical results and the experimental results may be due to two factors: changing of flow patterns and mass transfer of constituents.