Current progress in the design and setup of a SOFC/GT hybrid power plant

Kurzfassung

The German Aerospace Center (DLR) is setting up a hybrid power plant with 30 kW electrical power output. It consists of a SOFC and a micro gas turbine (MGT). The hybrid power plant can reach electrical system efficiencies greater than 60 % throughout a wide operating range. Due to the SOFC’s high operation temperature and incomplete fuel utilisation, the exhaust gas will always contain usable energy. The MGT will use this energy to provide compressed and preheated air for the SOFC and generate electricity. Before entering the cathode the compressed air will be preheated in the turbine exhaust heat exchanger. The SOFC will be operated at elevated pressure, which has positive effects on its efficiency. Therefore the SOFC is located in a pressure vessel to allow for an operating pressure of up to 0.3 MPa. The hot SOFC exhaust is led to the combustion chamber of the MGT where the unused fuel is burned. The gases are then expanded via the turbine. At the moment testing of different peripheral components is being performed. The power plant start-up is planned for 2017 starting first with a standalone SOFC- as well as a MGT-system. In both systems the behaviour of the missing component will be emulated. These standalone systems will be used to test control strategies and create experimental performance data. The data is further used for model validation, to predict the operating range, heat losses and pressure losses of the combined system and for development of hybrid system control strategies. Once the standalone systems are tested sufficiently, the combined system will be build-up in 2018. The build-up progress, the technical challenges and the design decisions will be explained on the poster. Additionally, an overview of all major system components will be presented.