Some Practical Aspects of Staged Premixed, Low Emissions Combustion

Abstract

An experimental program to research, develop, and demonstrate an axially staged, premixed low emissions combustor is described, with particular emphasis on the many mechanical and thermal problems which were encountered and which seem characteristic of the type. Of these, the risks of autoignition and flashback in the premixing duct were perhaps, the most severe. Their elimination imposed severe constraints on premixing duct geometry and indeed, dictated the layout of the whole combustor. Nevertheless, it proved possible to retain conventional technology to a large extent including the basic combustor structure and mounting arrangements and normal fuel injector accessibility. Large emissions reduction capability was demonstrated to be possible though not within conventional combustor dimensions.