Air Path Design, Technical Definition and Pre-Calibration of an Ultra-Lean Hydrogen Engine Based on OD/1D Simulation

Abstract

<div class="section abstract"><div class="htmlview paragraph">Transport sector decarbonization is a key requirement to achieve Green House Gases emissions reduction. Future regulations and the large deployment of Low Emission Zones (LEZ) will lead to deep changes in this sector. The green hydrogen appears as a promising fuel, containing no carbon. H2 Internal combustion engine (H2 ICE) offers the opportunities of quick refueling, known reliability, relative low total cost of ownership. It is based on mature manufacturing processes and tools. Hence this solution can be commercialized in a near future, offering a short term pathway to decarbonization and a H2 market growth accelerator.</div><div class="htmlview paragraph">However, hydrogen combustion in air generates NOx emissions, which should be reduced close to zero to fulfill future requirements.</div><div class="htmlview paragraph">The HyMot project gathers seven public and industrial partners to develop an H2 engine for Light Commercial Vehicle (LCV) application offering the same performances as the replaced Diesel Engine. Target is intercity use with access to LEZ. The consortium develop an H2 engine almost from blanksheet which will be integrated in a demonstrator. The minimum air fuel ratio target will be 2.5 on the whole engine map, so that NOx emissions stay at a very low level. This requires a specific air path to reach performance targets, with H2 and vehicle constraints.</div><div class="htmlview paragraph">This paper presents the 0D/1D model developed to design this new air path, define its architecture and choose the most efficient components. We will present the assumptions, the used methodology and the management of the different actuators. The model was used to build a virtual database to size some mechanical elements and the cooling system, define the valve lift and to supply boundary conditions for the combustion chamber and the after – treatment devices. Both static and transient conditions were studied to give some hints to calibration department in advance.</div><div class="htmlview paragraph">The authors are aware that a purely simulation-based study has significant limitations when it comes to characterize the behaviour of an internal combustion engine. Further research will involve an experimental validation step for the results presented here as soon as real engine data are available.</div></div>