Towards Conceptual Understanding of Pre-Ignition Mechanisms in Hydrogen-Fueled Engines – Recent Progress at Sandia National Laboratories

Authors

A. Srna, T. Lee, G. Nyrenstedt, Sandia National Laboratories, Livermore; R. Rajasegar, Colorado School of Mines, Golden:

Year

2024

Print Info

Production/Publication ÖVK

Summary

Pre-ignition is a key barrier to reaching diesel-like power density, low-end torque and efficiency in hydrogen engines. The complexity of underlying processes and range of potential pre-ignition sources (hot-spots, combustion residuals, glowing particles, carbonaceous deposits and oil droplets) make efficient mitigation of this abnormal combustion phenomenon a challenging endeavour, further aggravated by the lacking conceptual understanding of underlying mechanisms. To this end, Sandia has developed a framework to study pre-ignition using artificial pre-ignition sources in a heavy-duty hydrogen optical engine to develop a conceptual understanding of underlying mechanisms behind individual sources and to propose effective mitigation strategies. This lecture will cover the recent progress on this path – covering the aspects of hot-spot pre-ignition, the role of catalytically-active surfaces, the effects of hydrogen on auto-ignition of oil-vapors and the influence of hot combustion residuals. We will explain the mechanisms of hot-spot preignition suppression through delayed hydrogen injection, show that catalytic surfaces play a minimal role in pre-ignition, and outline the interplay between oil droplet size, evaporation and chemical interactions between hydrogen and oil that jointly govern the oil-induced preignition

ISBN

978-3-9504969-3-2

DOI

https://doi.org/10.62626/935j-t4ij