Flow characteristics of tangential and radial leakage in algebraic spiral variable cross-section electric scroll compressors

Abstract

The electric scroll compressor improves compression efficiency and reduces gas leakage by optimizing the scroll profile design, which significantly enhances HPAC performance. This study begins by selecting algebraic spirals to construct the scroll profiles, ensuring a smooth transition at the start of the scroll and eliminating the need for additional corrections. The baseline method is then used to analyze volume variation patterns in the working chambers during the meshing process of the orbiting and fixed scrolls. Next, variations in pressure, velocity, and temperature distributions within each chamber are analyzed using simulation software. A 3D transient flow model with radial and axial clearances of 20 μm and 15 μm, respectively, is established to investigate the impact of leakage flow on the transient flow field and system performance under these clearance conditions. The study shows that the tangential leakage velocity can reach 191 m/s, with the leakage direction opposite to the orbiting scroll’s motion, occurring throughout the entire compression process. Radial leakage is characterized by a symmetrical clearance distribution between the top of the orbiting and fixed scrolls, with leakage occurring only on one side, from the high-pressure to the low-pressure chamber. The leakage direction is along the normal direction at the top of the scroll, with a maximum velocity of 103 m/s. As the main shaft speed increases, the discharge temperature decreases. Furthermore, the increase in gas flow velocity leads to a reduction in both the number and intensity of vortices.