A flexible approach for accurate supercritical CO2 cycle performance modeling

Abstract

A rapid and efficient method for modeling supercritical CO₂ (scCO₂) Brayton cycles is presented, enabling calculations for both design and off-design conditions. A library is developed within an object-oriented simulation environment, to perform the calculations, incorporating an existing open-source library for accurately computing the specific properties of CO₂ near its critical point. For turbomachinery, compressors and turbines, predefined performance maps and appropriate similitude models are utilized for cycle simulations. The recuperator performance representation is based on effectiveness and is scaled according to mass flow rate for off-design operation. A particular feature of the approach is the implementation of adaptive modeling, for producing models that accurately represent operating installations, marking the first application of such a technique in supercritical CO₂ cycle modeling in general. The process of model building is demonstrated through application to a recuperated single shaft closed cycle. The accuracy of computations is validated through comparisons to published results.