声学法重建炉膛温度场研究

Study on reconstruction of furnace temperature field by acoustic method

大型工业锅炉内部燃烧环境恶劣复杂,对于炉膛内温度场的监测具有非常重要的意义。声学法测温作为一种新型的非接触测温方法,具有传播速度快、测量范围广、不受环境干扰等优点。为得到炉膛的温度场可视化结果,基于有限元法,利用COMSOL平台构建炉膛单峰偏斜温度场模型,模拟声波在炉膛内的传播情况,并根据互相关算法计算声波飞行时间,运用最小二乘法和插值算法对炉膛温度场进行还原。结果表明:运用互相关算法求得的飞行时间和理论飞行时间最大相对误差为0.81%,误差原因在于声源信号的伪前移现象,还原出来的温度场和单峰偏斜温度场模型平均绝对误差为31 K,具有很好的重建效果。

The combustion environment in large-scale industrial boiler is very fierce and complex,so it is very important to monitor the temperature field in the furnace.As a new non-contact temperature measurement method,acoustic method has the advantages of fast propagation speed,wide measurement range and free from environmental interference.In order to get the visualization result of the temperature field in the furnace,based on the finite element method,the single peak deflection temperature field model is built by using the COMSOL platform to simulate the sound wave propagation in the furnace,the acoustic flight time is calculated by cross correlation algorithm,and the furnace temperature field is reconstructed by least squares and interpolation algorithm.The results show that the maximum relative error of the flight time and the theoretical flight time obtained by cross-correlation algorithm is 0.81%,which is due to the pseudo forward shift of the sound source signal,the average absolute error of the temperature field model is 31 K,which has a good reconstruction effect.