Where published:
Year:2025
Twin Screw compressors are widely used in the refrigeration sector, chillers, and applications like heat pumps due to their high durability and reliability. In this study, the use of an ultra-low GWP refrigerant R1234ze(E) and oil injected operation of a test compressor is evaluated using thermodynamic chamber model. A 4/5 lobe combination with an N type rotor profile is used. Design exploration is set up to analyse parameters of wrap angle, rotor length and built-in volume index to improve the rotor geometry at a rated pressure ratio of 8 and speed of 10,000 rpm. A full operating condition performance map is then obtained on the improved geometry. A 12% improvement in refrigeration capacity from 86 to 96 kW was achieved with a 5% higher adiabatic efficiency. Further, a detailed CFD model is employed to verify these design changes. Performance results from the chamber and CFD models are compared and indicate an average of 8% difference in the refrigerant mass flow rate and compressor power.