基于Python的CO2/O2氛围下柴油燃烧火焰特征分析

Python-based flame characterization of diesel combustion in CO2/O2 atmosphere

摘要:

为分析柴油在CO2/O2氛围下燃烧的火焰特征，利用光学定容燃烧室测试并拍摄了6种不同工况下的柴油燃烧过程. 基于自编的Python代码对火焰图像进行后处理，提取出火焰浮起长度、红绿分量比、平均亮度、相关性系数、面积变化率和重叠率等特征参数并进行分析. 结果表明：在空气和CO2/O2氛围下，柴油火焰浮起长度和相关性均随燃烧进程先增大后减小再增大，平均亮度则先增大后减小，其在空气下和35% CO2+65% O2氛围下的峰值分别为210.75 px和138.89 px. 在火焰发展阶段，红绿分量比保持在0.8~1.2之间，而在火焰熄灭阶段，随着CO2浓度减小和O2浓度增大，红绿分量比有所减小. 与在空气下燃烧相比，柴油在CO2/O2氛围下的燃烧火焰形状更加细长，湍流现象更加明显，火焰浮起长度缩短，平均亮度下降.

Abstract:

To analyze the combustion characteristics of diesel fuel in a CO2/O2 atmosphere, optical constant volume combustion chamber tests were conducted to measure and capture the combustion processes under six different operating conditions. The resultant flame images were subject to post-processing using custom Python code, enabling the extraction of parameters including flame lift-off height, red-green ratio, average luminosity, correlation coefficient, area change rate, and overlap ratio. The findings indicate that, in both air and CO2/O2 atmospheres, the flame lift-off height and correlation initially increase, then decrease, before experiencing a subsequent increase throughout the combustion process. Conversely, the average luminosity demonstrates an initial increase followed by a decline. Specifically, in the air and 35% CO2 + 65% O2 atmospheres, the peak values of flame lift-off height were measured as 210.75 px and 138.89 px, respectively. During the flame development stage, the red-green ratio remains within the range of 0.8 to 1.2, while in the flame extinction stage, it decreases as the CO2 concentration decreases and the O2 concentration increases. Compared to combustion in air, the combustion of diesel fuel in a CO2/O2 atmosphere displays an elongated flame shape, heightened turbulence, reduced flame lift-off height, and diminished average luminosity.