In the context of decarbonizing the transport sector, the focus is more and more on heavy commercial vehicles and mobile off-road machinery. Vehicle and engine manufacturers, suppliers, and science have partnered up in the “PoWer” project for a thorough investigation of the cross-application use of concepts for powertrains driven by hydrogen-powered engines for CAVs (commercial, construction, and agricultural vehicles). The project in which KIT (Karlsruhe Institute of Technology) is involved with three institutes is headed by the automotive supplier MAHLE. The Federal Ministry for Economic Affairs and Climate Action is funding “PoWer” with around EUR 5 million over a period of three years; the project is supported by TÜV Rheinland.
Thanks to properties such as high efficiency, robustness, and low engine-out emissions, hydrogen-powered engines have many advantages that make them particularly suitable for construction and agricultural machinery applications. It is also possible to convert machinery such as excavators, combined harvesters, or conveyor vehicles, from conventional internal combustion engines to hydrogen engines. To facilitate the future implementation of this technology, three KIT institutes take part in the “PoWer” project, examining hydrogen combustion in engines, suitable exhaust-gas catalysts, and the behavior of materials exposed to hydrogen.
Efficient Use of Hydrogen in Complex Engines
“Due to the low ignition limit and the broad flammability range of hydrogen, undesired auto-ignition may occur. It is crucial to avoid this phenomenon in order to prevent damage to the engine,” as Dr. Uwe Wagner from KIT’s Institut für Kolbenmaschinen (Institute of internal combustion engines, IFKM) says, explaining the challenges. Therefore, the IFKM researchers investigate how hydrogen-based fuel can be used in the safest and most efficient way in CAV engines – based on intake pipe or direct injection technology. “In addition, the geometry of the engine and the influx of lubricating oil into the combustion chamber play a key role for a smooth combustion process,” says Wagner. In order to test and optimize different injection strategies and engine parameters, the researchers use a single-cylinder research test unit and a multi-cylinder engine.
Environmentally Friendly Energy Source for Off-road Applications
“In order to comply with current and future exhaust-gas limits, it is necessary to provide not only a low-emission engine, but also efficient exhaust-gas catalysts,” explains Dr. Patrick Lott from KIT’s Institute for Chemical Technology and Polymer Chemistry (ITCP). “The specific operating conditions of hydrogen engines can be very challenging for the catalysts,” says Lott. This is why the ITCP team examines how existing catalyst systems behave in the interaction with hydrogen-powered engines. The researchers want to find out how to improve the engine durability and efficiency in order to adapt them to the new operating conditions. At the same time, the scientists are working out innovative concepts for exhaust treatment so that hydrogen can be used as an environmentally friendly energy source in off-road applications.
How Hydrogen Impacts Material Properties
“The contact with hydrogen can considerably decrease the strength and deformability of metallic materials,” explains Dr. Stefan Guth from KIT’s Institute for Applied Materials – Materials Science and Engineering (IAM-WK). This is why the IAM-WK researchers investigate the effect of hydrogen on typical materials used for the components of combustion engines. To do so, they conduct mechanical materials testing under the influence of hydrogen, in particular with cyclically changing loads as they occur typically in engine operation. A main goal for the research group is to develop and establish methods for assessing the influence of hydrogen on material strength. “After all, we want to provide recommendations for the safe and efficient use of the materials to our industry partners,” says Guth.
About the “PoWer” Project
Headed by MAHLE, the project’s participants are, besides KIT, DEUTZ AG, the German Aerospace Center (DLR), Purem GmbH, Claas KGaA mbH, the TU Braunschweig, Liebherr GmbH, Nagel Maschinen- und Werkzeugfabrik GmbH, Umicore S.A., NGK Europe GmbH, and Castrol Limited as partners.
Being “The Research University in the Helmholtz Association”, KIT creates and imparts knowledge for the society and the environment. It is the objective to make significant contributions to the global challenges in the fields of energy, mobility, and information. For this, about 10,000 employees cooperate in a broad range of disciplines in natural sciences, engineering sciences, economics, and the humanities and social sciences. KIT prepares its 22,800 students for responsible tasks in society, industry, and science by offering research-based study programs. Innovation efforts at KIT build a bridge between important scientific findings and their application for the benefit of society, economic prosperity, and the preservation of our natural basis of life. KIT is one of the German universities of excellence.
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