Two phase pressure drop characteristics in a horizontal smooth pipe refrigeration ammonia (R717) system

Abstract

This paper focused on comparison of pressure drop characteristics verses the vapour qualities and modeled of ammonia refrigeration system using the results of experiments and simulation results in a virtual environment. In this study two-phase ammonia fluid flow system with mass fluxes from 50 to 100 kg/s.m2, vapour qualities between 0 and 1, and saturation temperatures from -20oC to 30oC were considered. The single-phase pressure drop equation with a modified fluid density was used to predict the two-phase pressure drop of the system. The results indicate that two phase pressure drop is dependent upon the average kinetic energy density of the flow, hydraulic diameter and friction factor of the pipe.