Analysis and Optimization of Diesel Injection Strategy to Minimize Unburned Hydrogen in a Hydrogen–Diesel Dual-Fuel Medium-Speed Marine Engine

Abstract

To advance shipping decarbonization, hydrogen is increasingly recognized as a viable zero-carbon fuel. Currently, a hydrogen/diesel dual-fuel medium-speed engine represents an optimal prime mover for ships. However, challenges such as the large cylinder dimensions of marine medium-speed engines and the low temperatures at the combustion chamber walls can hinder efficient flame propagation, leading to the emission of unburnt hydrogen. This not only diminishes the engine’s mechanical output but also poses significant safety risks. To address these issues, this study employs computational fluid dynamics (CFD) modelling to explore optimal diesel injection strategies that minimize unburnt hydrogen emissions in such engines. Specifically, this research examines the impacts of the diesel injection start angle, spray tilt angle, and injection duration on hydrogen combustion efficiency. The findings reveal that fine-tuning injection parameters substantially lower the fraction of unburned hydrogen. Adjusting the injection timing from 9.5°CA BTDC to 49.5°CA BTDC decreases the unburnt hydrogen fraction from 50% to 3%. Furthermore, modifying the spray tilt angle from 75.5° to 55.5° further decreases it to 2%, while shortening the injection duration from 35°CA to 34°CA achieves the lowest unburnt hydrogen fraction at just 1%. These results underscore the effectiveness of diesel injection strategies in optimizing the combustion in hydrogen/diesel dual-fuel marine medium-speed engines, offering a pathway for similar applications in the sector.

Keywords

Hydrogen/diesel dual-fuel / Marine medium-speed engine / Diesel injection strategy / Computational fluid dynamics (CFD) / Unburnt hydrogen emission

References

[1] Anthony Amsden L. A block-structured KIVA program for engines with vertical or canted valves, 1999. Los Alamos, Los Alamos National Laboratory (LANL)

[2] Beale JC, Reitz RD. Modeling spray atomization with the Kelvin-Helmholtz/Rayleigh-Taylor hybrid model. Atomization and Sprays, 1999, 9(6): 623-650.

[3] Cho ES, Ruminski AM, Aloni S, Liu YS, Guo J, Urban JJ. Graphene oxide/metal nanocrystal multilaminates as the atomic limit for safe and selective hydrogen storage. Nat Commun, 2016, 7: 10804.

[4] Dimitriou P, Tsujimura T, Suzuki Y. Low-load hydrogen-diesel dual-fuel engine operation–A combustion efficiency improvement approach. International Journal of Hydrogen Energy, 2019, 44(31): 17048-17060.

[5] DNV. Assessment of selected alternative fuels and technologies in shipping, 2019. [Accessed on April 25, 2024]. Greenhouse gas emissions from global shipping.

[6] DNV. The role of combustion engines in decarbonization: Seeking fuel solutions, 2021. [Accessed on May 15, 2024].

[7] Du H, Chai WS, Wei H, Zhou L. Status and challenges for realizing low emission with hydrogen ultra-lean combustion. International Journal of Hydrogen Energy, 2024, 57: 1419-1436.

[8] Duan Y, Sun B, Li Q, Wu X, Hu T, Luo Q. Combustion characteristics of a turbocharged direct-injection hydrogen engine. Energy Conversion and Management, 2023, 291: 117267.

[9] Gatts T, Li H, Liew C, Liu S, Spencer T, Wayne S, Clark N. An experimental investigation of H₂ emissions of a 2004 heavy-duty diesel engine supplemented with H₂. International Journal of Hydrogen Energy, 2010, 35(20): 11349-11356.

[10] Gao J, Wang X, Song P, Tian G, Ma C. Review of the backfire occurrences and control strategies for port hydrogen injection internal combustion engines. Fuel, 2022, 307: 121553.

[11] Gomes Antunes JM, Mikalsen R, Roskilly AP. An experimental study of a direct injection compression ignition hydrogen engine. International Journal of Hydrogen Energy, 2009, 34(15): 6516-6522.

[12] Han Z, Reitz RD. Turbulence modeling of internal combustion engines using RNG k-ε models. Combustion Science and Technology, 1995, 106(4–6): 267-295.

[13] Hanafi Gharehlar H, Ebrahimi M, Hosseinzadeh M, Hosseini S. Hydrogen/diesel RCCI engine performance assessment at low load. International Journal of Hydrogen Energy, 2024, 58: 200-209.

[14] International Maritime Organization. Marine Environment Protection Committee (MEPC 80), 2023. [Accessed on April 25, 2024].

[15] Jabbr AI. Combustion and emission characteristics of IC engines fueled by hydrogen and hydrogen/diesel mixtures and multi-objective optimization of operating paramete, 2020. Rolla, Missouri University of Science and Technology

[16] Khairallah HA. Combustion and pollutant characteristics of IC engines fueled with hydrogen and diesel/hydrogen mixtures using 3D computations with detailed chemical kinetics, 2015. Rolla, Missouri University of Science and Technology

[17] Liew C, Li H, Nuszkowski J, Liu S, Gatts T, Atkinson R, Clark N. An experimental investigation of the combustion process of a heavy-duty diesel engine enriched with H₂. International Journal of Hydrogen Energy, 2010, 35(20): 11357-11365.

[18] Liu X, Seberry G, Kook S, Chan QN, Hawkes ER. Direct injection of hydrogen main fuel and diesel pilot fuel in a retrofitted single-cylinder compression ignition engine. International Journal of Hydrogen Energy, 2022, 47(84): 35864-35876.

[19] Liu Y, Jia M, Xie M, Pang B. Enhancement on a skeletal kinetic model for primary reference fuel oxidation by using a semidecoupling methodology. Energy & Fuels, 2012, 26(12): 7069-7083.

[20] MAN Energy Solutions. MAN to investigate engine concepts for maritime hydrogen applications, 2023. [Accessed April 25, 2024].

[21] Mitsui Engineering & Shipbuilding. World’s first successful hydrogen combustion operation with a large marine engine, 2024. [Accessed April 25, 2024].

[22] Olmer N, Comer B, Roy B, Mao X, Rutherford D. Greenhouse gas emissions from global shipping, 2013–2015 Detailed Methodology, 2017. Washington, DC, USA, International Council on Clean Transportation: 1-38

[23] O’rourke P, Amsden A. A particle numerical model for wall film dynamics in port-injected engines, 19962000-2013. SAE Transactions.

[24] Qu W, Fang Y, Song M, Wang Z, Xia Y, Lu Y, Feng L. Hydrogen injection optimization of a low-speed two-stroke marine hydrogen/diesel engine. Fuel, 2024, 366: 131352.

[25] Qu W, Fang Y, Wang Z, Sun H, Feng L. Optimization of injection system for a medium-speed four-stroke spark-ignition marine hydrogen engine. International Journal of Hydrogen Energy, 2022, 47(44): 19289-19297.

[26] Senecal P, Pomraning E, Richards K, Briggs T, Choi C, McDavid R, Patterson M. Multi-dimensional modeling of direct-injection diesel spray liquid length and flame lift-off length using CFD and parallel detailed chemistry, 20031331-1351. SAE Transactions.

[27] Schmidt DP, Rutland CJ. A new droplet collision algorithm. Journal of Computational Physics, 2000, 164(1): 62-80.

[28] Sharma P, Dhar A. Compression ratio influence on combustion and emissions characteristic of hydrogen diesel dual fuel CI engine: Numerical Study. Fuel, 2018, 222: 852-858.

[29] UNCTAD. Review of maritime transport 2021, 2021. [Accessed on May 15, 2024].

[30] Verhelst S, Wallner T. Hydrogen-fueled internal combustion engines. Progress in Energy and Combustion Science, 2009, 35(6): 490-527.

[31] Wärtsilä. Hydrogen test, 2023. [Accessed April 25, 2024].

[32] Wang X, Sun B, Luo Q, Bao L, Su J, Liu J, Li X. Visualization research on hydrogen jet characteristics of an outward-opening injector for direct injection hydrogen engines. Fuel, 2020, 280: 118710.

[33] Xie Y, Liu J, Qin J, Xu Z, Zhu J, Liu G, Yuan H. Numerical simulation of hydrogen leakage and diffusion in a ship engine room. International Journal of Hydrogen Energy, 2024, 55: 42-54.

[34] Yuan Y, Wang J, Yan X, Shen B, Long T. A review of multi-energy hybrid power system for ships. Renewable and Sustainable Energy Reviews, 2020, 132: 110081.

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