Experimental characterisation of CO2 + C6F6 mixture: Thermal stability and vapour liquid equilibrium test for its application in transcritical power cycle

Nowadays supercritical CO2 cycles are considered as a promising alternative to the traditional steam cycle for power block in CSP plants with aim of enhancing system efficiency and reducing costs. This work deals experimental characterisation blend working fluid transcritical cycle: addition C6F6 dopant increases critical temperature allowing condensing hot environment ambient higher than 40 °C. The potential benefits on adopting this mixture passes through thermal stability test identifying its maximum operating Vapour Liquid Equilibrium measurements tuning Equations State, thus having good prediction thermodynamic properties. static method stress at different temperatures shows that can withstand about 600 °C an Inconel 625 vessel. Furthermore, standard Peng-Robinson optimised binary interaction parameter is selected preliminary assessment cycle. An 41.9% found optimum composition molar content 84% considering turbine inlet pressure 250 bar minimum 550 51 respectively.