Experimental measurements and computational predictions of the gas flow field in refrigerant oil separator.

Oil separators are essential components in a refrigeration system to ensure optimum performance of heat exchangers and overall plant efficiency. A key factor in being able to determine the performance of an oil separator is to understand the gas flow field within the unit which leads to droplet separation. This study utilises experimental data using Laser Doppler Anemometry (LDA) in a Perspex replica of a helical oil separator to validate a single phase computational model using Fluent 6.3.26. Four turbulence models were assessed against the experimental data which demonstrated that those based on the eddy-viscosity hypothesis fail to accurately predict the Precessing Vortex Core (PVC) which was visualised experimentally. The use of more complex turbulence approaches such as the Reynolds Stress Model (RSM) and Large Eddy Simulation (LES) produced results which were in reasonable agreement with the results obtained experimentally.