Numerical Simulation Study Of Flow Field In Twin Rotary Compressor

China has become a global manufacturing base for refrigeration,air conditioning and compressors and is at the forefront of compressor research and development.As a result of simple structure rolling compressor has become the most widely used refrigeration compressors.Single-cylinder rolling compressor has the most widely used in the small refrigeration unit(below 3 HP)in the field of home air conditioning.Compared with the single-cylinder rolling-rotor compressor,the double-cylinder rolling-rotor compressor has better torque properties,vibration properties,and smaller noise.In the compressor market with 3HP to 5HP cooling capacity,the scroll compressor is gradually occupied.Based on the ANSYS-CFX platform,a numerical simulation model is established for the twin-cylinder rolling piston compressor using the dynamic mesh technology.The three-dimensional compressible turbulence transient simulation was carried out in the fluid domain except for the gas-liquid separator in the compressor.The influence of the lubricating oil was neglected during the calculation.Only the R410A refrigerant in the compressor single-phase flow was considered.The error between the calculated cooling capacity and power is 6.28%and 4.7%respectively,which shows that the calculated results are credible,and the simulation results are reliable for the study of refrigerant flow characteristics in the compressor.The effects of the upper and lower cylinder exhausts on the pressure,the flow field,the temperature and the turbulent kinetic energy are analyzed.It is observed that a large pressure difference occurs between the upper space of the motor and the lower space of the motor in the compressor during the periodical exhaust of the upper and lower cylinders.This pressure difference is mainly caused by the influence of the gas flow path of the gas passage of the motor part and the gas passage of the upper and lower spaces of the muffler cover on the refrigerant flow.The analysis of axial gas force on the rotor system of the compressor is completed.Provided and verified a equation to evaluate the axial air force.On this basis,the axial force of the rotor system is analyzed for the same type of compressor with different structure motors by the established numerical simulation model of the double-cylinder rolling-rotor compressor.The influence of the rotor core on the axial gas force is obtained,and compared with some modified model experiments.Based on the numerical simulation model of twin-cylinder rolling piston compressor,a model of the stator cross-sectional area between the stator and the shell of the motor is numerically simulated.The relation between the area of the stator channel and the axial force is analyzed.