The focus of the research in the research power plant laboratory is the development and demonstration of innovative, fuel-flexible, low emission and highly efficient decentralized power plant concepts. The planned research power plant consists of two testing plants and is equipped with security mechanisms for testing using combustible gases.
The laboratory possesses a comprehensive and flexible media supply. Fixed connections of natural gas at various pressures up to 18 bar and compressed air up to 12 bar are complemented by supplies of other fuels via an external gas storage facility. Additionally, the synthesis gas facility which will compose the required individual gases (for example, H2, O2, CH4, CO, CO2) for the research power plant, is currently under construction. Small amounts of fuel can be supplied using gas cylinders/fuel storage cabinets.
A comprehensive process control and measurement data logging system for monitoring and controlling the processes and gathering the data produced, is currently being built. Amongst the lab’s most important equipment is an emission analysis facility (O2, CO, CO2, NO, NO2, UHC, H2O) for the continuous detection of pollutant emissions as well as an OH* chemiluminiscence camera which analyses the flame shape, its width and position. Laser-based methods from the department for combustion diagnostics are used to observe the flow and combustion processes in detail.
The cogeneration testing rig based on micro gas turbines has been designed for the development, testing and demonstration of fuel-flexible, gas turbine-based cogeneration plants for decentralized energy supply in a low output power range of up to 30 kWel. The testing rig displays the entire power plant process, from fuel preparation and gas turbine-based cogeneration to CO2 utilization.
The micro gas turbine EnerTwin from the company MTT is currently being used at an output of 3 kWel and has been modified and equipped in detail for research and development purposes.
Micro Gas Turbine Test Rig MTT
The micro gas turbine is used for the further development of gas turbine combustion systems. Minimizing emissions, observing reliability and the expansion of a stable operating range of technical combustion, as well as the flexible use of conventional and alternative fluid and gaseous fuels belong to the key research activities.
The experimental data gained from the micro gas turbine help to validate numerical cycle and combustion simulations. The micro gas turbine is used as a testing platform for power plant concepts such as the gas turbine-based cogeneration plant and the hybrid power plant.
In order to investigate the dynamic combustion processes, a visually accessible combustion chamber is currently being developed for the micro gas turbine in order to enable laser-based measurements.
Summary of the Testing System
The MTT micro gas turbine compresses ambient air using a radial compressor to 3 bar (full load). Before the air is fed into the combustion chamber, it is heated to around 700°C. The recuperator increases the electrical efficiency by using the waste heat from the turbine to pre-heat the air. This pre-heated air is burned with the injected fuel in the combustion chamber. Exhaust resulting from this process is decompressed to ambient pressure in the turbine. A subsequent water heat exchanger used to produce heating energy cools the exhaust gas to a temperature between 20-50°C, depending on the connected heating system. The turbine, compressor and electric generator are all located on one shaft. The speed of the shaft reaches max. 240,000 revolutions per minute. The high-frequency alternating current generated is first converted to direct current and then to the desired supply frequency and voltage using power electronics.
The micro gas turbines have been modified and equipped in detail in order to examine system components as well as the system as a whole.
Current research topics:
For the development, testing and demonstration of a properly connected hybrid power plant, consisting of a pressurized solid oxide fuel cell (SOFC) and a micro gas turbine (MGT), a testing rig is currently being built. The target electric output of the pilot plant is between 15-30 kWel. The micro gas turbine from the company MTT forms the basis of the hybrid power plant, with an electric output of 3 kWel.