二甲醚发动机组合燃烧压力振荡特性研究  

Pressure Oscillation Characteristics of Compound Combustion for DME Engine

作　　者：侯军兴[1] 杨海鹏 郑路 李树豪 张华阳[1] 安晓东 HOU Junxing;YANG Haipeng;ZHENG Lu;LI Shuhao;ZHANG Huayang;AN Xiaodong(Zhengzhou University of Aeronautics,School of Aeronautics and Astronautics,Zhengzhou 450046,China;Zhengzhou University of Technology,School of Mechanical-electronic and Vehicle Engineering,Zhengzhou 450044,China)

机构地区：[1]郑州航空工业管理学院航空宇航学院,河南郑州450046 [2]郑州工程技术学院机电与车辆工程学院,河南郑州450044

出　　处：《车用发动机》2022年第4期36-40,48,共6页Vehicle Engine

基　　金：河南省高等学校重点科研项目计划(22A470010);河南省科技攻关计划(22102210287);动力机械与工程教育部重点实验室开放课题。

摘　　要：研究了不同转速下二甲醚发动机组合燃烧的压力振荡特性,确定了压力振荡的时域特征和频域特征,考察了进气道引入燃料量(PI)对缸内压力在不同频域的子信号峰值的影响规律。研究结果表明,转速1500 r/min下,PI由0.77 mg/s增加至1.37 mg/s时,放热率曲线均呈三阶段放热,缸内压力级频谱曲线包括速降段、缓降段和波动段三个阶段。1100 r/min时规律类似。PI增加,HCCI燃烧低温放热部分峰值增加,峰值相位提前;高温放热部分由单峰变为双峰;扩散燃烧部分波动变剧烈。缸内压力带通滤波得到低频域子信号p_(1)、中频域子信号p_(2)和高频域子信号p_(3),其中子信号p_(1)对应正常燃烧压力,子信号p_(2)和p_(3)对应燃烧压力振荡。燃烧状态决定了子信号各个循环的峰值。PI增加,子信号p_(1)各个循环的峰值均增加。正常燃烧状态,子信号p_(3)各个循环的峰值均很小,子信号p_(2)的峰值明显大于子信号p_(3)的峰值。发生轻微压力振荡时,子信号p_(3)各个循环的峰值显著增加。发生剧烈压力振荡时,子信号p_(2)各个循环的峰值显著增加。The pressure oscillation characteristics of DME compound combustion at different speeds were studied.The time-domain and frequency-domain characteristics were determined.The effect of the fuel amount introduced into the intake port on the sub-signal peaks of in-cylinder pressure in the different frequency-domains was investigated.The results show that the curve of heat release rate produces three stages and the spectrum curve of in-cylinder pressure level also produces three stages of rapid drop,slow drop and fluctuation when the intake fuel amount increases from 0.77 mg/s to 1.37 mg/s at 1500 r/min.The law is also similar at 1100 r/min.With the increase of intake fuel amount,the peak of low-temperature heat release part for HCCI combustion increases and the phase advances,the high-temperature heat release part changes from a single-peak to a double-peak,and the diffusion combustion part fluctuates sharply.The sub-signals of low-frequency p_(1),medium-frequency p_(2) and high-frequency p_(3) are obtained from the in-cylinder pressure by the band-pass filter,and the sub-signal of p_(1) corresponds to the normal combustion pressure and the sub-signals of p_(2) and p_(3) correspond to the combustion pressure oscillation.The combustion state determines the peak value of each cycle for sub-signal of p_(1),p_(2) and p_(3).As the intake fuel amount increases,the peak of each cycle for sub-signal of p_(1) increases.The peak of each cycle for sub-signal of p_(3) is very small,and the peak of each cycle for sub-signal of p_(2) is significantly larger than that for sub-signal of p_(3) in normal combustion.The peaks of each cycle for sub-signal of p_(3) and p_(2) increase significantly in the slight and severe pressure oscillation respectively.

关 键 词：二甲醚 组合燃烧 压力振荡 时域特性 频域特性 

分 类 号：TK421.42[动力工程及工程热物理—动力机械及工程]