刘志强　黄霄　廖伊丹　彭小兰　张建智　谢伟

摘   要：针对电站锅炉炉管泄漏问题，对基于时延估计法的定位方法进行了试验研究.通过外放高频声音信号模拟炉管泄漏信号，采用互相关算法估计两两通道间的时延值，根据距离公式建立定位方程，采用牛顿迭代法对其求解，获得泄漏点位置.试验结果表明：当声源为脉冲信号时，时延估计值很准确，当声源为连续周期声源信号时，时延估计值最大在-T/2～T/2（声源信号的周期）范围内变化;在一定范围内，采样率越高，时延值精度越高，定位效果越好;相较于声速，采样率对定位结果的影响更大.

关键词：锅炉炉管;声学检测;时延定位;采样率

中图分类号：TN91                      文献标志码：A

Investigation on Location of Leakage Noise Based

on Time Delay Estimation Method

LIU Zhiqiang1，HUANG Xiao1，LIAO Yidan1，PENG Xiaolan2，ZHANG Jianzhi1，XIE Wei1

（1. School of Energy Science and Engineering，Central South University，Changsha 410083，China;

2. Hunan Special Equipment Inspection & Testing Institute，Changsha 410111，China）

Abstract：Aiming at the leakage problem of boiler tubes in power plants，the location method based on time delay estimation was studied. The leakage signal of the furnace tube was simulated by the external high-frequency sound signal，and the multi group delay value was measured by the cross-correlation algorithm. The location equation was established according to the distance formula，and then solved by Newton iterative method，by which the leakage point coordinate was obtained. The experimental results show that the time-delay is effective only for impulsive sound source signals，and when it is the continuous periodic source，the estimation of time-delay is in the range of -T/2～T/2 （where T is the period of the source signal）. In a certain range，the higher sampling rate results in the higher delay value precision and the better effect of location;when compared with the sound speed，the sampling rate has greater impact on the location results.

Keywords：boiler tube;acoustic detection;localization of time delay;sampling rate

爐管泄漏是锅炉安全运行的重大隐患，因此，有必要对其进行及时有效的检测.常规的检测方法有：目测观察法、锤击检测法、声学检测法等[1-2].目测观察法和锤击检测法在我国中小型电厂应用得最早、最广泛，但是其主观因素强、准确率不高且不能提前预测，总体效果不佳.针对声学检测法的定位问题，各国学者进行了广泛而深入的研究，波束形成法[3-5]、高分辨率谱估计法[6-7]相继被提出，这些方法虽然具有较好的定位能力，但也受到算法复杂、传感器数量多、成本高、需要环境和噪声的先验知识、不适用实时系统等的限制.时延估计法[8-10]实时性好，算法简单，且能获得较高的定位精度.

本文将时延估计方法应用于炉管泄漏噪声的定位[11-13]中，首先分……