At present, heavy-duty vehicles with long range and or high-performance requirements account for by far the largest proportion of CO2 emissions in the transport sector. For this application, the Hydrogen Internal Combustion Engine (H2 ICE) offers a promising addition to fuel cells for CO2-free transport.
The aim of this paper is to further present the MAHLE H2 research engine and the potential improvements and solutions that can be achieved by optimizing the engine power cell unit (PCU), covering key challenges of an H2 fuelled ICE and its impact on lube oil consumption and blow-by.
The study considers the results of real-time thermal load of the pistons and cylinder walls using H2-combustion measurements as input data for the components simulation model calibration. The model considers the complete oil transport by checking PCU dynamics, structural and lubrication analysis. Furthermore, material solutions known from gaseous fuels, as well as hydrogen-specific studies to cope with dry tribological conditions, were part of the requirements considered when selecting the component materials.
To test and validate the simulated models, a state-of-the-art 12.8 l diesel HD engine was converted to hydrogen and commissioned on a MAHLE test bench. Through a European Stationary-Cycle (ESC), tests were performed by continuously measuring the engine performance focusing on exhaust gases, blow-by, oil emission and oil consumption.
The paper concludes with a review of the key engine component results and their application to a heavy-duty hydrogen SI engine. These provide an additional basis for future developments with alternative fuels such as hydrogen, which offers a promising CO2-neutral solution for the transport sector.
