Tangential leakage flow control with seal-grooves on the static scroll of a CO2 scroll compressor

Abstract

• The seal-grooves are arranged on the sidewall of the static scroll. • Tangential leakage flow is reduced by the seal-grooves on the static scroll. • The seal-grooves arranged in the compression chamber brings more benefit. • Multi seal-grooves prolongs the energy dissipation of the tangential leakage flow. • Both streamwise and secondary axial vortex contribute to the sealing effect. Tangential leakage is an important factor affecting the aerothermodynamic performance of the scroll compressor, and existing methods to reduce tangential leakage usually aim at narrowing leakage path. In this paper, continuous seal-grooves arranged on the sidewall of static scroll was proposed, in order to achieve the passive flow control of the tangential leakage. Numerical methods were conducted to investigate the flow characteristics of tangential leakage in the radial clearance with seal-grooves. The impacts of diverse geometric parameters and arrangement schemes on the performance of the scroll compressor were also discussed. Results showed that throttling effect, flow separation of tangential leakage, and secondary axial turbulence was the main influence mechanism of the seal-grooves. Appropriate groove depth and spacing contributes to the developments of flow separation and secondary axial turbulence in seal-grooves, while increasing seal-groove number brought better flow control effect. Based on the above results, the seal-grooves arranged on the sidewall of compression chamber increased separately the volumetric efficiency and isentropic efficiency by 1.63% and 1.32%, and the volumetric efficiency also improved by 0.99% when the seal-grooves were arranged in the suction chamber. This work may provide a new flow control method of tangential leakage in the scroll compressor.