Numerical Simulation for Estimating Two-phase Flow of Pure Refrigerants through Short Tube Orifices

摘要

A detailed one-dimensional numerical simulation of the fluid-dynamic behaviour of short tube orifices expansion devices working with pure refrigerants has been developed. The discretized governing equations are coupled using an implicit step by step method in the flow direction. A special treatment has been implemented in order to consider transitions (subcooled liquid region and equilibrium two-phase region) and the sudden contraction (inlet section). The numerical model allows analysis of aspects such as geometry, different working conditions, critical or non-critical flow conditions, transient and steady-state situations, etc. Comparison of the mass flow rate obtained by the numerical simulation and experimental data presented in the technical literature will be shown in order to demonstrate the capabilities of the developed model.