Analysis of a directly heated oxyfuel supercritical power generation system

Directly heated supercritical oxy-fuel gas turbines have potential to provide a higher thermal efficiency with carbon capture compared to current gas turbine systems. Furthermore, due to the higher density of the working fluids the turbomachinery footprint can be reduced significantly. Motivated by the advantages of the directly heated supercritical power system, this paper presents the analysis of such a system. The analysis was conducted using ASPEN HYSYS assuming two different phases of combustion feed system including the gaseous and liquid phases. P-v diagrams for both cycles were generated and compared to each other to determine which is more efficient. The analysis revealed that the liquid phase feeding system produced a higher net power than the gaseous phase feeding system. The investigation showed that the system yielded a higher net efficiency of 55.1% when gaseous carbon dioxide is employed as a diluent.