Micro Gas Turbine Combustion Chamber Design and CFD Analysis

In the framework of the non-standard fuel combustion research in micro-small turbomachinery, a newly designed micro gas turbine combustor for a 100-kWe power plant in CHP configuration is under development at the Ansaldo Ricerche facilities. Combustor design starts from a single silo chamber shape with two fuel lines, and is associated with a radial swirler flame stabiliser. Lean premix technique is adopted to control both flame temperature and NO_x production. Combustor design process envisages two major steps, i.e. diagnostics-focussed design for methane only and experimentally validated design optimisation with suitable burner adaptation to non-standard fuels. The former step is over, as the first prototype design is ready for experimental testing. Step two is now beginning with a preliminary analysis of the burner adaptation to non-standard fuels. The present paper focuses on the first step of the combustor development. In particular, main design criteria for both burner and liner cooling system development are presented. Besides, design process control invoked both 2D and 3D CFD analysis. Two turbulence models, FLUENT standard k-ε model and Reynolds Stress Model (RSM), are refereed and the results compared. Here both a detailed analysis of CFD results and a preliminary analysis of main chemical kinetic phenomena are discussed.