Numerical study of intake flow field inside the high-speed refrigeration scroll compressor with spiral suction channels in the motor rotor

To control the temperature of the electric motor, the suction gas is introduced flowing through the motor in hermetic scroll compressors. For high-speed compressors, this flow resistance is high, which results in decreasing of the efficiency. In this paper, spiral flow channels were designed inside the motor rotor to decrease the suction flow resistance and increase the refrigerant flow rate inside the scroll compressor. Simulation of the suction flow through the motor was carried out. Two structure of straight and spiral intake channels were brought into the simulation model, under 3000 rpm, 5000 rpm, 7000 rpm and 9000 rpm. The results showed that the spiral channels could increase the refrigerant flow rate inside the motor rotor and the suction pressure of the compressor, and with the increase of the motor speed, the effect of the intake supercharging improved. At 9000 rpm, the suction pressure at the suction port of the compressor increased by about 4% by using spiral channels, while the mass flow rate increased by about 6%. The increases of total refrigerant flow rate in spiral channels are mainly due to the increase in unblocked channels. The size and the layout of the balance weight have a great effect on intake flow.