The micro gas turbine Turbec T100 is the key element for the development of gas turbine combustion systems. Goals of the research include pollutant minimization and a reliability analysis of technical combustion systems. A further priority of the research activities is fuel flexibility in conventional and alternative fluid and gas fuels.
Experimental data gathered under real technical conditions is used to validate the numerical situation. The micro gas turbine is also a central testing system for the investigation and application of various power plant concepts for sustainable, decentralized energy generation and for a hybrid power plant consisting of a high-temperature fuel cell and a gas turbine.
Summary of the testing system
The Turbec T100 compresses ambient air using a centrifugal compressor. The compression ratio is at 4.5:1 (full load). In order to increase the electrical efficiency of the system, a recuperator is used to heat the compressed air to around 600°C. Then the air is fed into the combustion chamber, where the lean mixed air/fuel mixture is combusted. The turbine entry temperature is around 950°C, the turbine exit temperature around 645°C. The turbines, compressor and electric generator are all located on one shaft. The speed of the shaft reaches max. 70,000 revolutions per minute. Electricity is produced using a permanent magnet generator, which is also used as a motor to start the micro gas turbine. The high-frequency alternating current generated by the generator is converted to the desired supply frequency and voltage using power electronics. In order to increase the total efficiency of the testing system, it is possible to remove the remaining thermal energy in the micro gas turbine’s exhaust.
In order to investigate the dynamic combustion process, an optically accessible combustion chamber is used. This means that laser-based measurement techniques can be applied.
The laboratory is equipped with safety features suited to the testing of combustible gases. A synthesis gas unit is used to ensure a reliable supply of various combustible gases. The synthesis gas unit composes the gas mixture from various individual gases (for example, H2, O2, CH4, CO, CO2) directly before it is fed into the micro gas turbine.
Additionally, the emissions of the micro gas turbine can be measured using an exhaust gas analysis, which continuously measures the residual content of O2, water and the amount of unburnt hydrocarbons (UHCs) CO, CO2, NO und NO2. An OH* chemiluminiscence camera analyses the flame shape, its width and position. Laser-based methods from the department for combustion diagnostics are used to observe the flow combustion processes in detail.