摘要
炉膛内温度分布的实时监测对大型燃煤锅炉的控制和诊断具有重要意义。声波飞渡时间作为声学测温方法中的重要参数,因炉膛内复杂的燃烧环境而很难精确测量。以国内机组容量为50 MW的燃煤锅炉为研究对象,分析了炉膛内背景噪声以及不同频率的单频信号在炉膛内的衰减特性,从而确定测温中的声波信号频段。并提出采用互相关时延估计法结合希尔伯特变换取包络的方法获得声波飞渡时间。实验结果表明,采用取包络的方法相比未取包络具有更高的精度和更好的稳定性。
Real-time monitoring of the temperature distribution is of great significance to the control and diagnosis of large coal-fired boilers. Time of flight（TOF） as an important parameter of acoustic pyrometry is difficult to measure in the complex combustion furnace environment. In this paper, the coal-fired boiler of 50 MW unit capacity is taken as the research object. The background noise and the attenuation characteristics of the single-frequency signals with different frequencies in the furnace are analyzed to determine the frequency band of the acoustic signal in the temperature measurement. And, the cross-correlation time delay estimation method combined with the Hilbert transform for envelope extraction is used to obtain the time of flight（TOF）. The experimental results show that the proposed method has better accuracy and stability over the non-envelope extraction method.
作者
吴莉
陈励军
WU Li;CHEN Li-jun(School of Information Science ＆ Engineering,Southeast University,Nanjing 210096,Jiangsu,China)
出处
《声学技术》
CSCD
北大核心
2018年第3期211-216,共6页
Technical Acoustics
