Optimum Turbine and Compressor Inlet Pressures for Maximum Net Specific Work of a Regenerative Supercritical Carbon Dioxide Brayton Cycle
Year: 2025
Type: article
Abstract: The Supercritical CO2 (sCO2) Brayton cycle has recently gained more attention and is considered a promising power cycle. In this study, relationships for determining the optimum compressor and turbine inlet pressures, maximizing the net specific work of regenerative and simple sCO2 Brayton cycles, were developed. A key innovation of this work lies in expressing these relationships in terms of dimensionless quantities which have not been previously reported in the literature. The effects of turbine and compressor inlet pressures, inlet temperatures as well as their efficiencies on the optimum compressor and turbine inlet pressures and the maximum net specific work were investigated. The results indicated that, under some operating conditions, no compressor inlet pressure caused a peak of net specific work and the criterion of the optimum compressor inlet pressure could not be satisfied. An increase in turbine inlet pressure led to a slight reduction in the optimum compressor inlet pressure, while an increase in compressor inlet pressure resulted in an increase in the optimum turbine inlet pressure. Both increases had positive effects on the maximum net specific work. The optimum turbine inlet pressure increased with an increase in turbine inlet temperature and decreased with an increase in compressor inlet temperature. However, increases in both temperatures caused opposite changes in the optimum compressor inlet pressure. Increases in compressor and turbine efficiencies resulted in reducing the optimum compressor and increasing the optimum turbine inlet pressures. The optimum pressure calculated based on the ideal gas assumption is not applicable for sCO2 Brayton cycle, as it could result in an absolute percentage difference of 113.01% in the prediction of the optimum compressor inlet pressure.
Source: International Energy Journal
Institution: Kasetsart University
Language: English
Subfield: Mechanical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W4411948202