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Numerical study on pressure oscillation suppression of low-speed marine engine with in-cylinder direct injection of natural gas
journal contribution
posted on 2020-01-08, 11:20 authored by Chengwei Yuan, Bo Liu, Xiaoxiao Jiang, Lei Zhou, Rui Chen, Haiqiao WeiBased on the computational fluid dynamics (CFD) software (CONVERGE), the simulation model of a large low-speed two-stroke marine engine in which pilot diesel and natural gas are injected directly in cylinder was established. Validated by the experimental data from the literature, the model was then applied to studying the suppression effect of the Miller cycle and natural gas two-stage injection strategy on the pressure oscillation in high pressure direct injection mode. The calculation results indicated that when the exhaust valve was closed later, the overall combustion pressure was lower, both the combustion phase and the moment of severe pressure oscillation were delayed. The intensity of pressure oscillation was reduced with smaller delay of exhaust valve closing, while it was increased instead with an excessive delay. This was primarily attributed to the competitive relation between in-cylinder thermodynamic state and auto-ignition characteristics of fuel. Adjusting the pre-injection quantity of natural gas would reduce the formation of premixed combustible mixture before combustion, thus reducing the proportion of premixed combustion in the combustion phase, which could effectively suppress pressure oscillation, but could also reduce the output power and increase the fuel consumption. Compared with the pre-injection quantity, varying injection interval has less effect on the pressure oscillation, but the excessive injection interval would affect the combustion phase, resulting in considerable power loss. A reasonable injection strategy can ensure the power output while suppressing intense pressure oscillation.
Funding
Marine Low-Speed Engine Project Phase I (CDGC01-KT0308)
History
School
- Aeronautical, Automotive, Chemical and Materials Engineering
Department
- Aeronautical and Automotive Engineering
Published in
Neiranji Gongcheng/Chinese Internal Combustion Engine EngineeringVolume
40Issue
6Pages
56 - 63Publisher
Shanghai Neiranji Yanjiusuo, Shanghai Internal Combustion Engine Research InstituteVersion
- VoR (Version of Record)
Rights holder
© Editorial Office of Chinese Internal Combustion Engine EngineeringPublisher statement
This paper was accepted for publication in the journal Neiranji Gongcheng/Chinese Internal Combustion Engine Engineering and the definitive published version is available at https://doi.org/10.13949/j.cnki.nrjgc.2019.06.009.Publication date
2019-12-15Copyright date
2019ISSN
1000-0925Publisher version
Language
- zh
Depositor
Prof Rui Chen. Deposit date: 6 January 2020Usage metrics
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