Geometric modeling and performance analysis of a combined algebraic spiral scroll compressor

This study proposed a combined algebraic spiral (CAS) scroll compressor with a profile that consists of two algebraic spirals with different parameters smoothly connected by a higher-order curve. The advantage lies in the ability of the ending algebraic spiral to regulate the stroke volume and wrap size, while the starting algebraic spiral can control the discharge volume and the center part of the wrap, thus improving the geometric performance of the scroll compressor. The research established the geometric model of CAS scroll wrap and conducted parametric studies. The results indicate that CAS scroll compressor exhibits the minimum discharge volume, maximum stroke volume, and compression ratio when both the discharge volume chamber and the stroke volume chamber are entirely constructed using the algebraic spiral. Moreover, it was observed that the radial leakage curve length decreases as the polar angle at the connection point increases. Under identical wrap diameters and adequate minimum wall thickness, a larger spiral coefficient may be chosen for the ending algebraic spiral in order to enhance geometric performance. Conversely, a smaller spiral coefficient and spiral index for the starting algebraic spiral can improve compression and reduce leakage. Moreover, in comparison to a single algebraic spiral scroll compressor with an equivalent wrap size, CAS scroll compressor exhibits a 20.62% decrease in discharge volume, a 31.62% rise in compression ratio, a 30.75% reduction in radial leakage curve length, and superior geometric performance when compared to other algebraic spiral scroll compressors.