Aerodynamic Design and Numerical Analysis of a Centrifugal Compressor in Carbon Dioxide Heat Pump System

Carbon dioxide heat pump is a very promising energy‐saving technology. Based on the system parameters of the transcritical carbon dioxide heat pump cycle, this article has carried out 1D and 3D aerodynamic design of the compressor, and optimized the two‐stage parameters respectively. The reliability of the model is verified by comparing the calculated results with the published experimental data. At the same time, the grid independence of the compressor calculation model is verified. By optimizing the blade parameters, the first‐stage design efficiency is 78.8%, the second‐stage design efficiency is 79.7%, and the final 3D calculation efficiency of the compressor is 79%. By comparing the 1D prediction results with the 3D numerical calculation results, the 1D prediction results of the total pressure ratio at different speeds are in good agreement with the 3D simulation values. 3D calculation results show that there is no obvious airflow separation in the compressor passage, the fluid flow is subsonic, and no obvious high Mach number flow is found in the impeller or diffuser, indicating that the throat will not be blocked. This study provides a reference for the design and optimization of a carbon dioxide compressor.