Application of Airblast Atomizing Full Nozzles to Two Prototype Industrial Gas Turbines

This paper describes the development history of the CW352 engine combustor from the time when the persistent problem of a hot primary zone wall when operating in the regenerative mode while burning diesel oil was solved by the incorporation of an airblast atomizer. The problems of stability and poor atomization at low engine cranking speeds which accompany the use of airblast atomizers were addressed in the combustion laboratory but evaluation tests on an engine showed that further improvement in these areas would be beneficial. Concurrently, the preliminary design strategy of the CW182 combustor was predicted on the use of an airblast atomizer and its development program emphasized a phase of testing which examined the effects on nozzle performance of variations in local flowfield and of the use of atomizing air. The paper documents the particular problems met and solved in the areas of burning oil fuel in a regenerative machine, of maintaining low emissions of smoke while designing for single inventory of parts and providing stable combustion by the use of auxiliary atomizing air.