Numerical analysis of zero-carbon HCCI engine fuelled with steam diluted H2/H2O2 blends

Fernie, Oliver; Megaritis, Thanos; Ganippa, Lionel Christopher; Tingas, Efstathios-Al.

Abstract

The addition of hydrogen peroxide and steam to a hydrogen-fuelled HCCI engine was investigated at various fuel lean conditions ( = 0.2–0.6) and compression ratios (15–20) using a 0-dimensional numerical model. The use of hydrogen peroxide as an ignition promoter demonstrated increased IMEP (16%–39%), thermal efficiency (up to 2%), and reduced NOx (50%–76%) when compared to the conventional method of intake charge heating. When hydrogen peroxide was used as an ignition promoter, a 15% addition of steam was sufficient to reduce NOx by 93%–97%, though this reduced IMEP and thermal efficiency slightly. When heat transfer was considered and steam addition was increased from 0%–10%, no increase in intake air heating was able to match the IMEP of 5% hydrogen peroxide addition without an increase in the equivalence ratio (up to 40%). The parametric space of hydrogen peroxide (0%–25%) and steam (0%–40%) addition was explored in view of engine performance metrics, showing the complete range of conditions possible through control of both inputs. A three-order reduction in NOx was possible through steam addition. An optimal balance of performance and emissions occurred at 5%–10% hydrogen peroxide and 10%–15% steam addition. In a study of compression ratio, very little hydrogen peroxide addition (<5%) was required to achieve 98% of the maximum efficiency at higher compression ratios (19–20), though at lower compression ratios (<17) impractical quantities of hydrogen peroxide were required. The 10% steam addition present at these conditions led to extremely low NOx levels for [] of 0.3 and 0.4, though at [] of 0.5 NOx levels would require some after-treatment. Maintaining constant a high or low load across steam additions was possible through reasonable adjustment of hydrogen peroxide addition.

Citation

Fernie, O., Megaritis, T., Ganippa, L. C., & Tingas, E. (2022). Numerical analysis of zero-carbon HCCI engine fuelled with steam diluted H2/H2O2 blends. Fuel, 326, Article 125100. https://doi.org/10.1016/j.fuel.2022.125100

• Journal Article Type: Article
• Acceptance Date: Jun 23, 2022
• Online Publication Date: Jul 1, 2022
• Publication Date: 2022-10
• Deposit Date: Jul 1, 2022
• Publicly Available Date: Jul 4, 2022
• Journal: Fuel
• Print ISSN: 0016-2361
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 326
• Article Number: 125100
• DOI: https://doi.org/10.1016/j.fuel.2022.125100
• Keywords: Hydrogen, HCCI, Ignition promoter, Hydrogen peroxide, Heavy duty engine, NOx
• Public URL: http://researchrepository.napier.ac.uk/Output/2882289
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S0016236122019408#d1e6902