二甲醚发动机组合燃烧压力振荡特性研究

侯军兴; 杨海鹏; 郑路; 李树豪; 张华阳; 安晓东

车用发动机 ›› 2022, Vol. 0 ›› Issue (4) : 36-40.

栏目

二甲醚发动机组合燃烧压力振荡特性研究

侯军兴¹，杨海鹏²，郑路²，李树豪¹，张华阳¹，安晓东¹

作者信息 +

Pressure Oscillation Characteristics of Compound Combustion for DME Engine

HOU Junxing¹,YANG Haipeng²,ZHENG Lu²,LI Shuhao¹,ZHANG Huayang¹,AN Xiaodong¹

Author information +

文章历史 +

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1 500 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。1 100 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p₁、中频域子信号p₂和高频域子信号p₃，其中子信号p₁对应正常燃烧压力，子信号p₂和p₃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p₁各个循环的峰值均增加。正常燃烧状态，子信号p₃各个循环的峰值均很小，子信号p₂的峰值明显大于子信号p₃的峰值。发生轻微压力振荡时，子信号p₃各个循环的峰值显著增加。发生剧烈压力振荡时，子信号p₂各个循环的峰值显著增加。

Abstract

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 1 500 r/min. The law is also similar at 1 100 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 p₁, medium-frequency p₂ and high-frequency p₃ are obtained from the in-cylinder pressure by the band-pass filter, and the sub-signal of p₁ corresponds to the normal combustion pressure and the sub-signals of p₂ and p₃ correspond to the combustion pressure oscillation. The combustion state determines the peak value of each cycle for sub-signal of p₁, p₂ and p₃. As the intake fuel amount increases, the peak of each cycle for subsignal of p₁ increases. The peak of each cycle for sub-signal of p₃ is very small, and the peak of each cycle for subsignal of p₂ is significantly larger than that for sub-signal of p₃ in normal combustion. The peaks of each cycle for sub-signal of p₃ and p₂ increase significantly in the slight and severe pressure oscillation respectively.

导出引用

侯军兴，杨海鹏，郑路，李树豪，张华阳，安晓东. 二甲醚发动机组合燃烧压力振荡特性研究[J]. 车用发动机. 2022, 0(4): 36-40

HOU Junxing,YANG Haipeng,ZHENG Lu,LI Shuhao,ZHANG Huayang,AN Xiaodong. Pressure Oscillation Characteristics of Compound Combustion for DME Engine[J]. Vehicle Engine. 2022, 0(4): 36-40