The last 10 years of combustor development are characterised by the introduction of lean premixed burners for dry low-NOx emissions. This was easy to achieve as long as sufficient excess air was available. The modern gas turbine with its high turbine inlet temperature and increased need for component cooling sees a competition for air between combustion and requirements in other areas.
The paper describes how these problems have been solved by changing the design of burners and combustion chambers. The goal of minimising the hot surface area for a given combustor volume is achieved with the annular combustors. The number of burners has been selected in order to achieve good cross ignition, uniform temperature distribution and reasonably short residence times with the minimum of components. Test results and experience with operation and maintenance are also reported.