Aerodynamic Characteristics of a Centrifugal Compressor Working in Supercritical Carbon Dioxide

摘要

Development of a closed cycle gas turbine with supercritical carbon dioxide as a working fluid is underway to generate power from low-range or intermediate-range waste heat sources. A demonstration test using a reduced scale turbomachine was conducted and the aerodynamic characteristics of a compressor were examined. A compressor was selected as centrifugal with 30 mm outer diameter and rated rotational speed of 1.7 kHz and mass flow rate of 1.2 kg/s. To reduce compression work, the operating condition at the inlet to compressor was chosen in a supercritical state close to the critical point of 7.38 MPa, 304 K where the compressibility coefficient z becomes markedly small and real gas effect dominant. The experimental range in terms of z is 0.16