Numerical investigation on property effects in a low speed supercritical carbon dioxide centrifugal compressor

Compressor is one of the key components in the closed Brayton cycle operating with supercritical carbon dioxide, but the design method is far from mature. The physical property effects on the 1D isentropic compression process and a low speed centrifugal compressor are numerically investigated in the present work. The results show that with similar inlet conditions, the physical property of the supercritical carbon dioxide results in lower outlet Mach number than the ideal air. Furthermore, the static pressure coefficient distribution is surprisingly almost the same between these two working fluids at low Mach number situations for both the compression process and the low speed centrifugal compressor. It indicates that lots of air compressor design experience can be well applied to the low speed centrifugal supercritical carbon dioxide compressor design.