喷点匹配策略对氨氢发动机燃烧特性的影响

Effects of Injection-Ignition Matching Strategies on Combustion Characteristics of Ammonia-Hydrogen Engines

摘要

针对氨气点火能量高、燃烧速度慢的问题,设计开发了主动预燃室式氨氢发动机燃烧系统,通过数值模拟的方法,研究了射流引燃模式下喷射/点火匹配策略对发动机燃烧特性的影响. 结果表明:喷点间隔较短的先喷后点匹配策略具有最佳的燃烧性能(燃烧持续期为 26.5 °CA,指示热效率为 43.7%),得益于预燃室形成了较为明显的浓度分层,有利于火核的形成和发展,提升了射流引燃的促燃效能,从而提高了燃烧的指示热效率,但由于缸内更高的燃烧温度,导致高温富氧区域产生更多的 NO_x,而低温积累形成的 N₂O 相对较低.

Abstract

Aiming at ammonia’s high ignition energy and low combustion rate, an active pre-chamber-type ammonia-hydrogen engine combustion system was designed and developed. The influence of injection/ignition matching strategies on engine combustion characteristics under jet ignition mode was numerically investigated. The results indicate that the “inject-before-ignite” strategy with a shorter injection-ignition interval delivers optimal combustion performance(combustion duration of 26.5 °CA, indicated thermal efficiency of 43.7%). This is attributed to the pronounced concentration stratification formed in the pre-chamber, which facilitates the formation and development of flame kernels, enhances the combustion-promoting efficacy of jet ignition, and thereby improves the indicated thermal efficiency. However, higher combustion temperatures in the cylinder lead to the increased NO_x emissions in high-temperature oxygen-rich zones, while N₂O formation due to low-temperature accumulation remains relatively low.

关键词

主动预燃室 / 氨氢发动机 / 射流点火 / 喷点匹配 / 促燃效能

Key words

active pre-chamber / ammonia-hydrogen engine / jet ignition / injection-ignition matching / combustion promotion efficiency

参考文献

[1] El—Shafie Mostafa, Kambara Shinji. Recent advances in ammonia synthesis technologies: Toward future zero carbon emissions[J]. International Journal of Hydrogen Energy, 2023, 48(30): 11237-11273.

[2] Pyrc Michał, Gruca Michał, Tutak Wojciech, et al. Assessment of the co—combustion process of ammonia with hydrogen in a research VCR piston engine[J]. International Journal of Hydrogen Energy, 2023, 48(7): 2821-2834.

[3] Qi Yunliang, Liu Wei, Liu Shang, et al. A review on ammonia—hydrogen fueled internal combustion engines[J]. eTransportation, 2023, 18: 100288.

[4] Wang Wentao, Herreros José M, Tsolakis Athanasios, et al. Ammonia as hydrogen carrier for transportation; investigation of the ammonia exhaust gas fuel reforming[J]. International Journal of Hydrogen Energy, 2013, 38(23): 9907-9917.

[5] Kobayashi Hideaki, Hayakawa Akihiro, Somarathne K D Kunkuma A, et al. Science and technology of ammonia combustion[J]. Proceedings of the Combustion Institute, 2019, 37(1): 109-133.

[6] Wang Qingxuan, Shen Juanya, Li Xiangchao, et al. Combustion and emissions of a spark—ignition ammonia—hydrogen engine at lean combustion conditions[J]. International Journal of Hydrogen Energy, 2025, 136: 261-274.

[7] Wang Bowen, Yang Can, Chen Yuxin, et al. Combustion and emissions of an ammonia heavy—duty engine with a hydrogen—fueled active pre—chamber ignition system[J]. International Journal of Hydrogen Energy, 2024, 90: 419-430.

[8] Yun Hongli, Bu Zidong, Yang Zhenzhong, et al. Optimization of fuel injection timing and ignition timing of hydrogen fueled SI engine based on DOE—MPGA[J]. International Journal of Hydrogen Energy, 2023, 48(25): 9462-9473.

[9] Lin Zhelong, Liu Shang, Sun Qiyang, et al. Numerical investigation of multiple hydrogen injection in a jet ignition ammonia—hydrogen engine[J]. International Journal of Hydrogen Energy, 2024, 77: 336-346.

[10] Huo Jinlu, Zhao Tongbin, Lin He, et al. Study on lean combustion of ammonia—hydrogen mixtures in a pre—chamber engine[J]. Fuel, 2024, 361: 130773.

[11] Liu Zongkuan, Wei Haiqiao, Shu Gequn, et al. Ammonia—hydrogen engine with reactivity—controlled turbulent jet ignition(RCTJI)[J]. Fuel, 2023, 348: 128580.

[12] Zhou Xinyi, Li Tie, Wang Ning, et al. Pilot diesel—ignited ammonia dual fuel low—speed marine engines: A comparative analysis of ammonia premixed and high—pressure spray combustion modes with CFD simulation[J]. Renewable and Sustainable Energy Reviews, 2023, 173: 113108.

[13] Kanchiralla Fayas Malik, Brynolf Selma, Olsson Tobias, et al. How do variations in ship operation impact the techno—economic feasibility and environmental performance of fossil—free fuels? A life cycle study[J]. Applied Energy, 2023, 350: 121773.

[14] Dimitriou Pavlos, Javaid Rahat. A review of ammonia as a compression ignition engine fuel[J]. International Journal of Hydrogen Energy, 2020, 45(11): 7098-7118.

[15] Zhang Xiaoyuan, Moosakutty Shamjad P, Rajan Rajitha P, et al. Combustion chemistry of ammonia/hydrogen mixtures: Jet—stirred reactor measurements and comprehensive kinetic modeling[J]. Combustion and Flame, 2021, 234: 111653.

[16] Gotama Gabriel J, Hayakawa Akihiro, Okafor Ekenechukwu C, et al. Measurement of the laminar burning velocity and kinetics study of the importance of the hydrogen recovery mechanism of ammonia/hydrogen/air premixed flames[J]. Combustion and Flame, 2022, 236: 111753.

[17] Otomo Junichiro, Koshi Mitsuo, Mitsumori Teruo, et al. Chemical kinetic modeling of ammonia oxidation with improved reaction mechanism for ammonia/air and ammonia/hydrogen/air combustion[J]. International Journal of Hydrogen Energy, 2018, 43(5): 3004-3014.

[18] Shrestha Krishna Prasad, Lhuillier Charles, Barbosa Amanda Alves, et al. An experimental and modeling study of ammonia with enriched oxygen content and ammonia/hydrogen laminar flame speed at elevated pressure and temperature[J]. Proceedings of the Combustion Institute, 2021, 38(2): 2163-2174.

[19] Chen Jundie, Jiang Xue, Qin Xiaokang, et al. Effect of hydrogen blending on the high temperature auto—ignition of ammonia at elevated pressure[J]. Fuel, 2021, 287: 119563.

基金资助

国家自然科学基金资助项目(52276100)