Potential of a Hydrogen Fuel-Share Combustion Concept for a Conventional Medium-Speed Marine Diesel Engine Technische Universitat Munchen, Engineering and Design

Format:

Book

Conference/Event

Author/Creator:

Achenbach, Tobias, author.

Contributor:

Jaensch, Malte

Kunkel, Christian

Mahler, Kay

Meinert, Robert

Prager, Maximilian

Rösler, Sebastian

Conference Name:

Automotive Technical Papers (2026-01-01 : Warrendale, Pennsylvania, United States)

Language:

English

Physical Description:

1 online resource cm

Place of Publication:

Warrendale, PA SAE International 2026

Summary:

To meet the International Maritime Organization's (IMO) short-term greenhouse gas (GHG) reduction targets, partial decarbonization of the existing fleet, often powered by medium-speed diesel engines, is required. One approach for reducing CO2 emissions is to enrich the charge air with hydrogen to substitute diesel. However, hydrogen's high reactivity can lead to combustion abnormalities such as backfire, pre-ignition, and knocking, thus limiting the feasible admixture rates. These challenges are particularly relevant in medium-speed diesel engines designed for high power output and efficiency at low rpm. While hydrogen fuel-share has previously been tested in small-bore engines at moderate loads, this study investigates the influence on combustion and achievable hydrogen admixture rates in a medium-speed, 4-stroke diesel engine operating with up to 30 bar net indicated mean effective pressure (net IMEP). To minimize retrofitting efforts and to preserve diesel performance, the investigations were conducted on a single-cylinder engine with representative design features of a conventional diesel engine: a high compression ratio, Miller valve timing, valve overlap, and a piston with deep valve pockets. The piston ring system is suited for heavy fuel oil (HFO) operation. Hydrogen was supplied via a port fuel injection (PFI) system. 0D/1D process simulations supplement the experimental data. Findings indicate that energetic hydrogen admixture rates of up to 43% are achievable at low loads, limited by an advancing start of combustion, and up to 15% hydrogen share at high loads, constrained by backfire. This results in an average CO2 reduction of ~22% on the E2 cycle for constant-speed main propulsion engines. Due to rising NOx emissions, the results are only applicable when meeting IMO Tier II limits with selective catalytic reduction (SCR). The results demonstrate that conventional medium-speed diesel engines are suited for hydrogen fuel-share operation and that CO2 reductions comparable to liquid natural gas (LNG) conversions are feasible

Notes:

Vendor supplied data

Publisher Number:

2026-01-5007

Access Restriction:

Restricted for use by site license