气流床撞击火焰声学特性与压力波动分析

摘要

Acoustic characteristics of impinging-flame noise of double opposed burners and its pressure fluctuations were studied using opposed multi-burner(OMB) entrained-flow bench-scale gasifier. The frequency spectrum analysis of noise signal and pressure signal of the impinging flame was done through the Hilbert-Huang transform. The results show that the high frequency pressure fluctuations are mainly caused by the complex combustion status in the impinging flame zone which generates the flame noise with the frequencies from 50Hz to 100Hz. The amplitude and waveform of the jet flow flame noise are influenced by low frequency pressure fluctuations and the reverse flow from the impinging zone. The acoustic signal of the impinging flame is somewhat related to the combustion status, and can be used for flame fault-diagnosis of gasifiers.%利用多喷嘴对置式气流床气化炉热模试验装置，对两喷嘴对置撞击火焰声学特性和压力波动进行了测量与实验研究，并通过Hilbert-Huang变换对火焰噪声信号及压力信号进行频谱分析。结果表明，气化炉内中高频压力波动主要由火焰撞击区内复杂的燃烧状况引发，并产生50~100 Hz频段的火焰噪声。射流火焰噪声受气化炉内低频压力波动影响，并且因来自撞击区的反向流的作用，火焰噪声的幅值和波形都会受到一定的影响。撞击区的火焰噪声信号与燃烧状况有一定的对应关系，可作为气化炉内火焰状况诊断的一种方式。