Investigation of a FLOX®-Based Combustor for a Micro Gas Turbine With Exhaust Gas Recirculation
Micro gas turbines (MGT) offer interesting advantages for the use in combined heat and power (CHP) systems. A possibility to raise the total efficiency of a MGT is the introduction of an external exhaust gas recirculation (EGR). The composition of the working fluid due to EGR affects the combustion process and the formation of pollutants. Changes in flame position, flame volume and flame intensity as well as rising CO emissions in state of the art industrial burners have been described by several authors before. This paper describes the experimental investigation of a single stage FLOX®-based combustor for a MGT in the power range of 1–3 kWel applied with EGR. The tests were performed on an atmospheric test rig with optical access. The combustion air was preheated up to 718 °C and diltued with N2, CO2 and steam. A probe of the exhaust gas was analyzed for emissions and OH* chemiluminescence measurements were performed. In addition to the experiments, chemical kinetic simulations were performed. Results show, that the examined combustor is able to work stable even at very low oxygen levels (down to 12.6 %) at combustor inlet, although the possible range of operation under EGR conditions is reduced. The measured increase of CO emissions matches to the performed simulations.