炉内单排换热器管阵列声传播特性数值研究

基于Twersky声波散射理论和光栅衍射理论,对炉内单排换热器管阵列的声传输特性进行了研究,分析了管排阵列对入射声波的反射、透射和衍射的物理机制,给出了计算管排阵列声透射与反射系数的数学模型,数值研究了管排阵列对声波的反射与透射系数随管间距、声波频率等参数变化的关系曲线,揭示了单排管阵列对声波传播具有截止和导通作用,并且其截止带和导通带的位置与管阵列结构参数和炉内温度有关。为研究多排管阵列的声传输特性、促进换热器管阵列泄漏声检测与定位技术和锅炉管束深处的声波除灰选频技术发展提供了理论基础。

Numerical Study on the Sound Wave Propagation Through a Row of Heat-exchanger Tubes in Boilers

Based on the Twersky's sound scattering theory and the grating diffraction theory,the sound transmission behaviors of a tube row in boilers are studied.The physical mechanisms of the reflection,transmission and diffraction characters about a tube row are analyzed.A mathematic model is established for calculating the sound wave scattered by a tube row.The transmission and reflection coefficients of a tube row varying with the tube-row structure and the sound frequency are calculated.It is revealed that there is some stop-band and pass-band effects with the tube row when sound wave propagating through it.The stop and pass band distribution is related to the tube-row structure parameter and temperature in boiler.This paper is helpful to study the sound propagation through many tube-rows and choose the working frequencies for the lake detecting and the soot cleaning technologies in the tube array.