Mahle Powertrain has announced that it is supporting Liebherr Machines Bulle SA in its research to develop hydrogen-fueled internal combustion engines.
According to the company, the work involves the use of its pre-chamber jet ignition system. Engine tests have shown that by using this technology, the mixture of hydrogen and air can be ignited and burned at a high compression ratio, which makes the combustion process very efficient and stable. This paves the way for hydrogen generated in climate-neutral processes to be used in heavy-duty and off-road applications, such as excavators, track vehicles, and wheeled loaders, the company said.
In order to achieve stable operation with a high compression ratio whilst avoiding engine knock and pre-ignition, hydrogen engines must be operated with a large amount of excess air. The energy from a conventional spark plug is not enough to ignite such a mixture. Mahle Jet Ignition solves the problem by burning a small amount of an ignitable mixture in a pre-chamber cylinder. The resulting gas plasma is passed through small openings into the main combustion chamber and, due to its high energy content, rapidly and evenly ignites the main gas mixture. Tests with H966 and H964 engines from Liebherr have delivered excellent results in terms of combustion speed, performance, and emissions.
Peter Wieske, Director Corporate Advanced Engineering, Mahle, said, 'The use of hydrogen as a combustion fuel has the potential to make many heavy-duty and off-road applications climate-neutral quickly. A large number of studies in recent decades have shown that hydrogen can be used in internal combustion engines without any problems.”
Bouzid Seba, Head of Predevelopment, Liebherr Machines Bulle, said the expertise of Liebherr’s engineering teams in off-highway engine combustion and research on alternative fuels has been critical in this project.
According to Mike Bunce, Head, Research, Mahle Powertrain US, the challenge is to stop engine knocking and premature ignition without reducing the compression ratio and thus efficiency and performance yield. 'Our joint tests suggest that we have found the right solution with MAHLE Jet Ignition,” he added.