Modeling of the SNL S-CO₂ Loop With ANL Plant Dynamics Code

The ANL Plant Dynamics Code (PDC) for the analysis of supercritical carbon dioxide (S-CO₂) Brayton cycle power converters has been under development at Argonne National Laboratory for several years. In previous years, limited validation of the PDC models on an individual basis was carried out using experimental data obtained from facilities directed at individual components. Recently, experimental data from the SNL/BNI small-scale S-CO₂ Brayton cycle demonstration that is being assembled in a staged fashion has been provided to ANL. The loop configuration with a single turbo-alternator-compressor (TAC) was modeled with the Plant Dynamics Code and the performance prediction of individual components and the entire loop obtained from the PDC was compared with the experimental data. Overall, reasonably good agreement is obtained for steady state conditions around the loop when a value is inferred for the heat loss downstream of the turbine such that a steady state loop energy balance can be established.