In order to understand the performance changes and potential risks of hydrogen assisted combustion in combustion chamber of a lean-combustion premixed gas turbine

a numerical simulation study of the hydrogen injection combustion process of natural gas was carried out in the combustion chamber of Siemens SGT-800 gas turbine. The fuel ignition

temperature distribution

flame formation and NO_x emission characteristics of the combustion chamber under five working conditions of 0

5%

10%

15% and 30% were investigated. Studies have shown that hydrogen-doped combustion in the current combustion chamber will lead to an earlier ignition position of the fuel

an increase in temperature peaks

a shorter axial length of the flame

and a gradual convergence of the outer duty flame towards the central mixer. The temperature distribution and flame morphology in the combustion chamber will not change significantly when the hydrogen-doped ratio is below 15%

but the ignition position in the mixer tube is seriously retracted at 30% hydrogen-doped ratio

and the flame on the outside is close to the nozzle outlet

which has a risk of tempering. In addition

the NO_x emission value of the combustion chamber outlet increases with the hydrogen doping ratio

and the NO_x emission value exceeds the standard by nearly 1/3 at 30%hydrogen doping ratio

indicating that high NO_x emission is also one of the factors restricting the high proportion of hydrogen doping in gas turbines.