The Automotive Gas Turbine and Nitric Oxide Emissions

Abstract

A model for the formation of nitric oxide, NO, in regenerative automotive gas turbine engines is presented. The model is shown to closely predict relative NO emission trends for an existing engine, while predicting absolute levels within a factor of 2. A typical “near future” automotive turbine cycle is then described. Engine performance and NO emissions are calculated for this cycle. The trade-off between fuel consumption and NO emissions for conventional combustor design is presented as a function of turbine inlet temperature. The methods by which NO emissions can be reduced are examined, and it is found that to meet the proposed 1976 Federal Emissions Standard for NO_x, the combustor's primary zone must be made considerably leaner and more homogeneous than is typical of current combustor designs.