Computational fluid dynamics (CFD) study on the pressure uniformity of symmetric working chambers in a scroll compressor for electric vehicle thermal systems

As a core component of thermal systems in electric vehicles, the scroll compressor plays a crucial role in energy saving and emission reduction by enhancing its performance. The uniformity of pressure within the symmetrical working chambers of the scroll compressor significantly affected the work efficiency. This study utilizes computational fluid dynamics simulation technology to investigate methods for improving the uniformity of pressure within the symmetrical working chambers of a scroll compressor. First, the axial clearance on one side was calculated for the first time. The results indicate that when the axial clearance was located at the top of the orbiting scroll, the maximum pressure difference in the symmetrical working chambers decreased from 1.21 MPa to 0.83 MPa. Second, the groove at the beginning of the orbiting scroll can significantly enhance pressure uniformity. Under the calculation model provided in this paper, the average power of the scroll compressor can be reduced by 232.58 W, a reduction of 17.39%, through the groove. Finally, this study presents matching principles for the design of the groove and exhaust ports to ensure that both working chambers are simultaneously connected to the exhaust port. When the diameter of the exhaust port was reduced, and the size of the exhaust port did not match the groove, under the low-pressure-ratio working condition, the maximum pressure difference of the compressor increased by 0.20 MPa, and the average power increased by 158.95 W. The above conclusions have a significant reference value for improving the performance of scroll compressors and extending the driving range of electric vehicles.