炉内温度声学测量的声源特性试验研究

TEST STUDY ON SOUND SOURCE BEHAVIOR OF SONIC MEASUREMENT FOR TEMPERATURE IN THE FURNACE

采用Labview和Matlab软件编写了各种电声程序,并在冷态炉膛试验台上对电站锅炉声学测温中的声源特性进行试验研究。结果表明:广义互相关延时估计经过滤波处理后能够在封闭混响环境下得到准确的时延估计值;采用广义互相关延时估计法后,正弦信号、三角波信号等不适合作为电声源信号;扫频信号具有较好的测量效果;泊松噪声信号和MLS序列信号的互相关函数具有尖锐峰值,适合作为声源信号;其它信号如Bernoulli噪声信号也具有较好的互相关性,经过特殊处理后也可以作为声学测温中的声源信号。这些试验结果,可为声学测温声源信号的选择及封闭混响环境中声波飞渡时间的测量提供重要参考。

By using Labview and Matlab softwares,various electro-sonic programme have been compiled,and test study being carried out on a cold furnace test stand for the sound source behavior in sonic measurement of temperature in utility boilers.Results show that the generatlized mutual correlation delay time estimation method can be used to obtain accurate value of delay time in a closed reverberatory environment after frequency-filtering treatment;the sinusoidal signals and triangle wave signals etc.are unsuitable to be used as the sound source signals after adopting the above-mentioned method;the frequency-scanning signals boast better measuring effectiveness;the mutual correlation function of the Poisson noise signal and MLS sequential signal boast sharp peak values,being suitable to be used as sound source signals;the other signals;such as Bernoulli noise signal,has also better mutual correlation behavior,through special treatment,can also be used as sound source signalin sonic temperature measurement.These test results can provide important reference for sound source selection and sonic wave flying transfer time measurement in the sonic temperature measurement.