电站锅炉对流烟道烟温声学监测技术关键

Theory and key techniques of flue gas temperature monitoring in convection gas pass using acoustic pyrometry in boiler

针对电站锅炉过热器、再热器超温问题,拟采用声学测温对流烟道烟气侧温度进行实时在线监测。搭建管阵列实验台,在实验室环境下研究管阵列对声波传播的影响。在锅炉现场环境下,利用人孔安装声学测点,对锅炉热态时对流烟道烟气温度进行监测,验证声学方法的可行性。结果表明,声波信号大部分可以透过管阵列传播过来。在管阵列环境下,声波飞渡时间可以由广义互相关时间延迟估计获得。声学法可以用来进行对流烟道内实际烟气温度的测量。

Aiming at the problem of boiler superheater and reheater over-temperature,acoustic pyrometry was used to online monitor the flue gas temperature in convection gas pass. A tube array experiment platform was built to study the influence of tube array on sound propagation under the laboratory environment. The acoustic measurement points were installed in the manhole of the boiler,and the flue gas temperature in convection gas pass was monitored in hot state using acoustic pyrometry,which verifies the feasibility of the acoustic pyrometry method. Study results indicate that most of the sound waves could travel through tube array; and in tube array environment,the time of flight of the sound wave could be obtained from the time delay estimation based on the generalized cross-correlation technique.Acoustic pyrometry can be used to measure the flue gas temperature in convection gas pass.