Centrifugal Compressor Map Prediction for Application in High-Temperature Heat-Pumps using different working gases

Kurzfassung

In the medium temperature range, replacing fossil energy sources through the use of hightemperature heat pumps is a promising technology. To meet the various requirements for temperature lift, efficiency and power range, turbomachinery are used. A radial compressor stage designed for air applications is used for this study at boundary conditions for water vaper as working medium at the inlet. Based on the established similarity criteria approach from Buckingham's Π-theorem, the compressor map for air can be recalculated for another gas - here for superheated water vapor. This analytical approach will be examined by 3D-RANS CFD calculations of the centrifugal compressor stage for both working media. The investigations show the predicted total pressure ratio based on the analytical approach and numerical methods and are primarily intended to indicate if the operating range can be represented accurately. It leads to the conclusion that the analytical approach gives a reasonable first guess of the performance map prediction concerning the pressure ratio and the mass flow range.