Design of Turbomachinery for the Supercritical CO2 Gas Turbine Fast Reactor

Turbomachinery design has been carried out for the supercritical CO2 turbine power generation system connected indirectly to Na cooled fast reactor of 600 MW(t). CO2 pressure is 20 MPa and temperature is 373 deg C and 527 deg C at the inlet and exit of IHX, respectively. Two recuperators of PCHE type can be designed in the reasonable sizes for these conditions. An inter-cooling was employed to achieve as high cycle thermal efficiency as possible and then three unique compressors: low pressure compressor (LPC), high pressure compressor (HPC) and bypass compressor (BC) are needed. The aerodynamic condition for the BC is most critical since it has large pressure ratio and relatively small flow rate. High enough efficiency values, which are 93.4%, 88.3%, 88.2% and 88.2%, were achieved for the turbine, LPC, HPC and BC, respectively. These values are higher than those assumed in the cycle calculation. Then, the value of cycle thermal efficiency of 42.5% was confirmed. No technical difficulty can be found though the gas bending stress becomes critical due to the large mass flow rate. (authors)