| 郭博田,王谦,钟汶君,等.氨–柴油双燃料发动机燃烧的光学诊断研究[J].内燃机工程,2024,45(3):1-10. |
| 氨–柴油双燃料发动机燃烧的光学诊断研究 |
| Optical Diagnostics Study of Ammonia-Diesel Dual-Fuel Engine Combustion |
| DOI：10.13949/j.cnki.nrjgc.2024.03.001 |
| 关键词:氨替代率 双燃料 喷射策略 火焰发展 内燃机 |
| Key Words:ammonia replacement rate dual fuel injection strategy flame development internal combustion engine |
| 基金项目:国家自然科学基金项目（52076103，52376113） |
|
| 摘要点击次数: 878 |
| 全文下载次数: 509 |
| 摘要:为了解决氨燃料在发动机中燃烧不稳定的问题，通过开展氨–柴油双燃料发动机燃烧过程的光学诊断研究，以获得柴油引燃氨的燃烧及火焰发展特性，研究了不同氨替代率及不同柴油喷射时刻对氨–柴油双燃料缸内燃烧和火焰发展特性的影响。结果表明：随着氨替代率的增加，缸压和放热率峰值先增加后减小，燃烧相位不断后移，滞燃期和燃烧持续期延长，70%和80%氨替代率下放热率峰值相比40%氨替代率降低了41.7%和58.8%。随氨替代率增加，火焰光强和火焰面积均逐渐减小，氨替代率为80%时，火焰向燃烧室中心的扩散燃烧速度变慢，火焰面积峰值为612.5 mm2，占燃烧室总面积约19%，燃烧表现较差；随着柴油喷射时刻的不断推迟，缸压和放热率峰值先增加后减小，燃烧相位不断后移，燃烧持续期先减小后增加，火焰光强和火焰面积均先增加后减小。-25°喷射时刻缸压和放热率峰值分别为4.28 MPa和115.4 J/（°），相比其他时刻具有较好的放热性能。与-20°喷射时刻相比火焰光强和火焰面积分别增加了15%和42.5%，此时燃烧室中心未燃区域最小，对氨有较好的引燃效果。 |
| Abstract:In order to solve the problem of unstable combustion of ammonia fuel in engines， optical diagnosis research on combustion process of an ammonia-diesel dual-fuel engine was carried out to obtain combustion and flame development characteristics of ammonia-diesel induced ammonia， and the influence of ammonia-diesel dual-fuel on in-cylinder combustion and flame development characteristics at different ammonia replacement rates and different diesel injection times was studied. The results indicate that with increasing ammonia substitution rates， the peak cylinder pressure and heat release rate initially increase and then decrease. The combustion phase continuously shifts later， and the ignition delay and combustion duration prolong. Compared to a 40% ammonia substitution rate， the peak heat release rate decreases by 41.7% and 58.8% at 70% and 80% ammonia substitution rates， respectively. The flame intensity and flame area both decrease gradually with increasing ammonia substitution rates. When the ammonia replacement rate is 80%， the flame diffusion to the center of the combustion chamber slows down， and the peak flame area is 612.5 mm2， accounting for about 19% of the total area of the combustion chamber， indicating poor combustion performance. As the diesel injection timing is delayed， the peak cylinder pressure and heat release rate follow a similar trend， with the combustion phase shifting later. The combustion duration initially decreases and then increases， while flame luminosity and flame area show an initial increase followed by a decrease. At -25° direct injection timing， the peak cylinder pressure and heat release rate are 4.28 MPa and 115.4 J/（°）， respectively， exhibiting superior heat release performance compared to other timings. Compared to -20° direct injection timing， flame luminosity and flame area increase by 15% and 42.5%， respectively， indicating improved ignition efficiency in the combustion chamber center， with the smallest unburned region， demonstrating favorable ignition effects with ammonia. |
|
查看全文 HTML
查看/发表评论 下载PDF阅读器 |