喷氢射流点火对煤层气发动机燃烧特性影响  

Effect of Hydrogen Jet Ignition on Combustion Characteristics of Coalbed Methane Engine

作　　者：何义团[1] 王乾[1] 秦子涵 付艳艳 HE Yituan;WANG Qian;QIN Zihan;FU Yanyan(College of Transportation,Chongqing Jiaotong University,Chongqing 400074,China)

机构地区：[1]重庆交通大学交通运输学院,重庆400074

出　　处：《郑州大学学报(工学版)》2025年第2期97-103,共7页Journal of Zhengzhou University(Engineering Science)

基　　金：国家自然科学基金资助项目(52276100);重庆交通大学研究生科研创新项目(CYS23500)

摘　　要：为避免大缸径低浓度煤层气发动机在发电过程中出现燃烧不稳、爆震等现象,对喷氢射流点火的助燃效果进行研究,探究点火-喷氢间隔对射流火焰结构以及对发动机助燃效能的影响。基于三维流体力学软件,固定喷氢时刻及喷氢脉宽,通过改变点火时刻来研究不同点火-喷氢匹配策略对发动机燃烧性能的影响。结果表明:在一定范围内先点后喷(喷氢前5℃A内点火)及边喷边点两种工况均可形成较为明显的烟羽射流火焰结构,可提高发动机燃烧速率,滞燃期及燃烧持续期相较于原机分别缩短了64%和68%;缸压峰值和放热率峰值分别提高2.1 MPa和1.05 kJ/℃A。另外,固定喷氢时刻改变点火时刻,先点后喷和边喷边点两种工况指示热效率相差不大,均在40%左右;而先喷后点的两组案例效率有所下降,分别为38.3%和36.7%。合理控制点火-喷氢时刻可使发动机指示热效率比原机提高约4%。In order to avoid the phenomena of combustion instability and knock in the process of power generation of large bore low concentration coalbed methane engine,the promoting effect on combustion of hydrogen jet ignition was studied.The influence of ignition-hydrogen injection interval on jet flame structure and combustion-supporting efficiency of engine were investigated.Based on the three-dimensional fluid mechanics software,the effects of different ignition-hydrogen injection matching strategies on the combustion performance of the engine were studied by changing the ignition time with fixed hydrogen injection time and hydrogen injection pulse width.The results showed that the obvious plume jet flame could be formed in the two working conditions of ignition before hydrogen injection(ignition in 5℃A before hydrogen injection)and ignition during hydrogen injection,which could improve the combustion rate of the engine.The ignition delay period and combustion duration were shortened by 64%and 68%respectively compared with the original engine.The peak pressure and the peak heat release rate were increased by 2.1 MPa and 1.05 kJ/℃A.Fixing the hydrogen injection time and changing the ignition time,the indicated thermal efficiency of the two working conditions of the ignition before hydrogen injection and the ignition during hydrogen injection was not much different,both of which are about 40%.The efficiency of the two groups of cases that ignition after hydrogen injection were 38.3%and 36.7%,respectively.The indicated thermal efficiency of the engine could be increased by about 4%compared with the original engine by reasonably controlling the ignition-hydrogen injection time.

关 键 词：低浓度煤层气 喷氢助燃 复合喷射 点火喷氢匹配 火焰结构 

分 类 号：U464.1[机械工程—车辆工程] TK431[交通运输工程—载运工具运用工程]