超临界CO₂径流透平一维计算模型的研究

Turbine,as the cyclic output power component,is one of the core components of the supercritical carbon dioxide (SCO₂) Brayton cycle.This paper determines a high-precision numerical simulation calculation model-SST(extended wall function)turbulence model by comparing with the experimental data of the SCO₂radial-inflow turbine from Sandia Laboratory in the United States. On this base,by comparing with numerical simulation results,the incidence loss,rotor passage loss and tip clearance loss for the SCO₂Brayton cycle radial-inflow turbine are analyzed emphatically,and the loss model combination suitable for SCO2 working fluid is determined. The Wasserbauer-Glassman model is selected for incidence loss,the best angle of incidence is calculated by Chen model; the CETI model is selected for rotor passage loss,and the Jansen model is selected for tip clearance loss. According to the selected loss model,the multi-condition flow rate and isentropic efficiency predictions of the high-pressure and low-pressure turbines are carried out and compared with the numerical simulation results. The results show that the maximum deviation of the high-pressure turbine does not exceed 2.4% and 1.5%,and the maximum deviation of the low-pressure turbine does not exceed 2.1% and 1.2%.