Development of a Jet-Stabilized Combustion System for the Use of Low-Caloric SOFC Off-Gas

A promising technology solution to meet the demands for highly efficient and clean CHP systems with the highest load and fuel flexibility is the SOFC/MGT hybrid power plant concept (HPP). In this concept, a solid oxide fuel cell (SOFC) is combined with a micro gas turbine (MGT) to use the hot and low-caloric SOFC off-gases for further energy production. In this study, the focus is set on the development of a suitable single-stage jet-stabilized combustor which combines the functionality of a gas turbine combustor and a SOFC off-gas burner for low-caloric SOFC off-gases at combustor inlet temperatures up to 1073 K. To experimentally characterize the newly developed SOFC off-gas combustion system beyond the turbine operating conditions in the HPP, atmospheric tests were carried out. The anode and cathode flows within the test series are provided without the SOFC being in place. Reflecting the resulting SOFC off-gas conditions at different possible HPP operating points, the results from variations of the cathode and anode mass flow rates, the O2 content and the LHV were carried out and are presented. The off-gas burner proves a wide operational stability of the combustion concept with CO emissions below 10 ppm and NOx emissions below 3 ppm. The shape and location of the flame is investigated using the OH* signal detected by an ICCD camera.