A Design Strategy for Supercritical CO2 Compressors

Abstract

The international scientific community researching the supercritical carbon dioxide power cycle has already developed the first turbomachinery designs, which are currently operating in reference laboratories worldwide. Nevertheless, the performance of this equipment is still quite far from the target values yielding fairly disappointing system efficiencies (65% vs. 80% total to total efficiency for radial compressors). In the light of these past results, the thermal Power Group (GMTS) at the University of Seville, Spain, has been researching the SCO2 cycle during the last few years. Hence, after researching elementary diffusion processes and some basic features of the system, the authors are now in the process of developing guidelines for compressor design based on one-dimensional codes developed in-house and CFD analysis. The results stemming from both approaches are presented in this paper showing that the rather simple 1D model is able to produce a fairly good model which can then be tuned with a more complex and computationally expensive 3D CFD code. The entire approach is presented in this paper, from the initial reference value for the key design parameters through the 1D code and to the multi-dimensional tool. The results of the two latter approaches are compared in detail in this paper.