Prediction of vapour-liquid equilibria of neon-nitrogen, neon-oxygen and neon-argon mixtures used in J-T refrigerators

Abstract

Neon is one of the main components of the mixture used in J-T refrigerators operating below 70 K along with nitrogen, argon and oxygen. The properties of mixtures of these fluids need to be estimated accurately for designing optimum mixture compositions for these refrigerators. However, the binary interaction parameters of neon and other cryogens are not readily available in the literature for the widely used cubic equations of state. The binary interaction parameters of neon-nitrogen, neon-argon and neon-oxygen mixtures for the Peng-Robinson equation of state and that of neon-oxygen mixture for the Helmholtz energy equation of state have been regressed in this work. The vapour-liquid equilibria of neon-nitrogen, neon-argon, neon-oxygen mixtures estimated with the Helmholtz energy and the Peng-Robinson equations of states are compared with experimental data.