Development of Micro Gas Turbine Combustor with a Recirculation Zone Induced by an Upward Swirl

3rd Report, Effect of a Primary Zone Configuration on Spray Combustion Characteristics and Combustion Gas Flow

Abstract

A low NO_x combustor for kerosene-fueled micro gas turbine based on a new concept was proposed. The combustor consisted of primary and secondary combustion zones, and they were connected by a throat. A swirler was set between the primary and secondary combustion zones. In order to enhance recirculation of burned gas in the primary combustion zone, combustion air was introduced through the swirler and forced to flow upward to the combustor bottom. In this study, effects of configuration of primary combustion zone on combustion gas flow in it were investigated. The length of primary combustion zone, swirler vane angle, diameter of throat and height of guide vane were changed independently from the standard configuration. Distributions of gas flow in the primary combustion zone were measured with LDA. The relation between combustion stability and the distributions of gas flow was discussed, and it was found that appropriate combustion gas recirculation in the primary combustion zone was necessary to keep combustion stability high.