CO2, rotary compressor, OCR, flow field, simulation
The oil circulation rate(OCR) of a CO2 inverter rotary compressor is higher than expected. The computational fluid dynamics(CFD) method is used to build a flow field simulation model of the compressor. Boundary conditions are determined according to the real running conditions of the compressor, involving the pressure, the temperature, the mass flow rate and other necessary parameters. There are four paths for refrigeration gas and oil flowing across: the motor rotor channel, the air gap between the motor rotor and the motor stator, the winding gap and the motor stator core cut. The CO2 mass flow rates of these four paths are obtained and compared. The pressure field in the compressor is obtained and analyzed, which determines the gas and oil flow pattern and path. The velocity is also investigated. The research shows: the CO2 mass flow rate through motor rotor channel and winding gap have a great influence on the OCR of CO2 inverter rotary compressors. The simulation result agrees well with the test result.