Mixture formation of a catalytic combustor for gas turbines -spray and evaporation characteristics of sprays injected from air-assist nozzle into high temperature air flow

摘要

An automotive ceramic gas turbine was developed to achieve high thermal efficiency and clean exhaust emission. A pre-vaporizing pre-mixing lean combustor installed in the gas turbine was developed, and a catalytic combustor for the gas turbine is under development. In these combustors, air-assist nozzles are used to obtain the required wide range of turn down ratio of fuel. It is still necessary to investigate the optimized mixture formation of the fuel and the air in the vaporizing tube of the catalytic combustor. This paper presents the behavior of the spray injected into the high-temperature air flow in a model vaporizing tube using the air-assist nozzle to understand the fundamental characteristics of the mixture formation process.