Investigation on the modifications of the suction flow passage in a scroll refrigeration compressor

Abstract

Six modification schemes are proposed by enlarging or reducing the volume of the suction flow passage based on a scroll refrigeration compressor to improve its performance. The three-dimensional unsteady Computational Fluid Dynamics model is established to investigate the flow field and the performance of every modified compressor numerically. The results indicate that the enlargement of the suction passage only improves the volumetric efficiency a little while the shrink of the passage can improve it effectively. The volume variation of flow passage due to the movement of orbiting scroll leads to the mass flow rate fluctuation. The volumetric efficiency increases and the mass flow rate pulsation decreases with the modification meshing angle among the tight modification schemes. The volumetric efficiency of the best modification scheme is 14.8% higher than the original one and its suction pulsation intensity is the lowest. But its indicated power increases a lot due to the large discharge loss and radial leakage loss, which result from the higher built-in volume ratio and pressure in the modified suction chamber. The build-in volume ratio of the chamber can be reduced by modifying the profile of the orbiting scroll to weaken the discharge loss of the compressor.