On Temperature of Working Fluid Supply to Combustion Chamber in CO2 Power Cycles with Oxy-Combustion of Methane

Abstract

The article addresses the thermodynamic issues of supercritical CO₂ power cycles at combustion of methane with oxygen. By the example of cycle with single-stage pump pressure rise with condensation of the working fluid, we consider the issue of ensuring the temperature of the working fluid supplied to the combustion chamber and the value of the theoretical specific heat flux into the regenerative system of cycle for a wide range of initial parameters at the turbine inlet. It has been shown that, depending on the pressure, the heat flux into the regenerative system is 700–1000 kJ/kgCO₂ when an initial temperature of 1000°C is provided, and its fraction in the total heat transfer to the working fluid is 0.5–0.6 in the zone of operational initial parameters. It has been determined that for the cycle efficiency to be high, the temperature of the working fluid supplied to the combustion chamber in the regenerative heat exchanger should be at least \(\sim 2/3\) of the temperature at its outlet.