Atmospheric Experimental Investigations of a Jet-Stabilized SOFC Off-Gas Combustor for a Hybrid Power Plant operated with Biogas

摘要

The increasing importance of decentralized energy production based on renewable resources requires gas turbine systems due to their low emissions and flexible energy conversion. Therefore, a suitable hybrid power plant demonstrator consisting of an SOFC (solid oxide fuel cell) coupled to an MGT (micro gas turbine) is being set up at the German Aerospace Center (DLR). This facility requires a burner concept for low calorific gases capable of combusting the exhaust products of the fuel cell system anode side, here referred to as SOFC off-gas. The combustor behavior for the demonstrator system is investigated using an atmospheric combustor test rig at DLR. The main aspect of this work is the combustor operation inside the power plant system with varying power demands and also varying methane contents, representing biogas operation. This is leading to operating points with very low heating values (LHV) which require a flame stabilization strategy via direct addition of natural gas / biogas into the SOFC off-gas before entering the combustor. This is tested in view of expected impacts on electrical system efficiency and other critical system parameters. The combustion system is furthermore investigated in view of CO emissions in various significant operating points.