PROJECTS

Turbomachinery for future energy conversion systems

Hydrogen research at the Institute of Turbomachinery and Fluid Dynamics (Leibniz Universität Hannover)

Successful research at universities and colleges plays a decisive role in the implementation of the energy transition. This is because research ensures technological innovation and helps to find solutions to complex challenges. Research also contributes to the development of new or improved products and processes that can increase competitiveness and open up new markets. This is particularly true in the context of hydrogen, as the development of the hydrogen economy is still in the starting blocks. But what does hydrogen research actually look like? We asked the Institute for Turbomachinery and Fluid Dynamics (TFD) at Leibniz Universität Hannover how research in the field of hydrogen is conducted at the institute

"The use of hydrogen in the mobility sector is currently in great demand: especially in areas where electrification is difficult to achieve - e.g. heavy goods vehicles, trains or air traffic - the use of hydrogen can provide the necessary decarbonization of transport," says Prof. Seume, Head of the Institute of Turbomachinery and Fluid Dynamics (TFD).

In this context, turbomachinery is an important component for improving the efficiency and power density of hydrogen utilization and thus reducing emissions. The Institute of Turbomachinery and Fluid Dynamics (TFD) at Leibniz Universität Hannover is conducting research on a wide range of projects in which the efficient use of hydrogen is being tested - whether chemically converted in the PEM fuel cell or burned in hydrogen engines and aircraft engines. Dr. Dajan Mimic, Group Leader Axial Compressors at TFD , also emphasizes the diverse areas of research in the context of hydrogen : "The topics of hydrogen and turbomachinery are linked in many ways. The possible applications range from hydrogen-powered gas turbines and fuel cell air supply systems to the complete integration of fuel cells in hybrid aircraft engine architectures."

Hydrogen the focus of numerous research projects

The diversity of hydrogen research also becomes clear when looking at the research projects being implemented at the TFD. In 2021, the research consortium "Sustainable Hydrogen Combustion Concepts (WaVe) ", funded by the state of Lower Saxony, was launched. As part of the project, the TFD is investigating possibilities for the so-called supercharging of hydrogen engines. The motivation is to reduce the combustion temperatures through a large excess of air and thus almost completely avoid nitrogen oxide emissions. This will make it possible to develop clean hydrogen combustion engines that guarantee the emission-free use of hydrogen in the mobility sector. In order to achieve this goal, the engine must be equipped with a highly efficient charging system that provides the necessary air. To this end, an axial compressor with a peak efficiency of over 80% is being developed at the institute and will be tested experimentally in the future. The project is expected to be completed in April 2024. The "WaVe" project was described at the NWN on the following page.

Focus on efficiency

Efficiency plays a decisive role in the use of hydrogen. The institute is therefore specifically dedicated to improving the efficiency of fuel cells - more specifically, PEM fuel cells. In the "ARIEL" project, the units for supplying air to the cathode (ARIEL) were optimized for this purpose.

Charging system for PEM fuel cells investigated in the ARIEL project. Source

In the "REZEBT" project , a recirculation blower was developed that transports unused hydrogen from the fuel cell outlet back to the inlet. This reduces the hydrogen requirement and significantly increases both the service life and the efficiency of the fuel cell. The PEM fuel cells are to be used in the 80 - 200 kW electrical power class. The main application is therefore in passenger cars and heavy goods vehicles - but the knowledge can also be transferred to rail, maritime and aviation applications.

REZEBT: Innovative hydrogen recirculation blower to increase the efficiency of fuel cells, source

In the SE²A Cluster of Excellence (EXC 2163), the knowledge generated to date is being applied and expanded to enable the use of PEM fuel cells in aviation. The challenges posed by the low ambient pressure at high altitudes are overcome by innovative compressor concepts. For example, mechanisms for actively influencing the flow through air injection and boundary layer suction are being investigated and combined with targeted humidification and cooling of the gas flow.

Young scientists can gain important experience

The TFD is also supporting a team of students in the construction of a hydrogen-powered multicopter in order to train young scientists in the use of hydrogen and allow them to gain important experience. The project, which is funded by the Hannover Region, involves the construction and testing of a multicopter with a diameter of over 2 meters and a take-off weight of almost 25 kg. By using hydrogen, the multicopter achieves longer flight times than are currently possible with conventional lithium-ion batteries. Further information can be found here and here.

Design of the multicopter, which is powered by a fuel cell with an output of 2.4 kW.

More about these and other hydrogen research projects at the institute: