THE JOURNEY TOWARDS LOWER NO_X EMISSIONS

摘要

In a world where environmental issues are a primaryrnconcern, increased attention is being paid to the impactrnof aviation. There are strong social and economicrndrivers to reduce emissions from aero engines.rnCustomer demands for cleaner technology, combinedrnwith tightening legislation, contribute to the competitivernpressures on engine manufacturers. Therefore reducingrnaero engine emissions is of vital importance to Rolls-rnRoyce. Internationally agreed targets include reducingrnNOx emissions to 50% of today’s levels, with progressrnbeyond this ultimately becoming necessary. Therncombustion system plus engine cycle and architecturernhave significant effect on the overall emissions from thernengine. This paper outlines the requirements for lowrnemissions, and a route to achieving these goals.rnSignificant research has been conducted into therncombustion and control system technologies needed tornreduce emissions. These technologies have now beenrndemonstrated in an engine environment. Numerousrncombustion system architectures have been identifiedrnand evaluated theoretically and experimentally. Novelrnfuel staging concepts have been explored to enable lowrnemissions to be realised without compromisingrncombustor functionality. Fuel staging has beenrnemployed within a single annular combustorrnarrangement, providing a degree of simplicity andrnensuring maximum commonality across a range ofrnengine applications. NOx levels compatible with therntargets have been achieved. The technologies developedrnwill be available for insertion into next generationrnproducts.