The Tornado gas turbine was designed at a time when emissions legislation was minimal and was developed through the eighties to accept water or steam injection for NOX reduction. In recent years it has become necessary to develop dry methods of emissions reduction for new engine sales and to enable existing operators to retrofit their engines when legislation demands.
The compact design of the Tornado’s centre section did not lend itself to a simple combustor changeout. The lean pre-mix dry low emissions (DLE) system developed for the Typhoon gas turbine required additional combustor length for CO burnout and could not be fitted into the existing casings of the Tornado engine. The challenge was therefore to redesign the centre section to enable the DLE system to be fitted without compromising the design of the compressor, HP turbine and gas generator rotor.
This paper describes the methodology used and the design of the engine centre section together with the results of design and performance validation undertaken including emissions measurements.