Hydrogen combustion in two-stage high-pressure gas turbine—thermal and flow simulations for performance comparison with fossil fuels

Abstract

Hydrogen energy forms an attractive solution for reducing greenhouse gas emissions from gas turbine systems. Although hydrogen combustion has been widely studied for combustors, only a few studies have considered the combustion effect downstream of the combustor. This study conducted an integral simulation of the combustion and flow of a GE-E³ aero-engine under hydrogen fuel and compared its performance with that of representative fossil fuels such as Jet A in an aero-engine and methane in an industrial gas turbine. All simulations were conducted under a constant heat input at the combustor and turbine inlet temperatures. During combustion simulation, the HyChem mechanism was applied to evaluate the composition of the products in an equilibrium model. Specifically, Reynolds-averaged Navier–Stokes steady simulation of a two-stage high-pressure gas turbine was conducted using the calculated boundary condition from the combustion simulation and k − ω shear stress transport γ turbulence model. The results revealed the high velocity of the hydrogen combustion flue gas owing to its low density under a large pressure difference. Overall, the power output, thermal efficiency, and fuel consumption were improved by hydrogen combustion. The thermal and flow results of the simulation can be used to develop hydrogen gas turbines.