离心泵空化状态下声发射信号的小波能量特征

为了探究离心泵空化状态下声发射信号的频率分布特征及其变化规律,该文采用小波分析方法对离心泵空化试验过程中不同空化状态下的声发射信号进行了能量特征提取,研究了不同频段内声发射信号的能量特征随离心泵汽蚀余量变化的关系。试验分析结果表明,在离心泵的空化现象尚未出现以及不同的发展阶段,离心泵进、出口处声发射信号的全频段和各分频段绝对能量和相对能量的变化具有各不相同的特点。〉31.25~62.5、〉62.5~125和〉125~250 k Hz这3个分频段的绝对能量随空化状态改变而变化明显,且变化趋势与全频段的变化趋势类似。〉31.25~62.5 k Hz分频段的相对能量在空化状态变化过程中基本保持不变,...

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Bibliographic Details
Published in农业工程学报 Vol. 31; no. 8; pp. 99 - 103
Main Author 刘忠 邹淑云 李志鹏 巨伟
Format Journal Article
LanguageChinese
Published 长沙理工大学能源与动力工程学院,长沙,410114 2015
Subjects
声发射
小波分析
离心泵
空化
能量特征
小波分析
空化
wavelet analysis
离心泵
energy features
声发射
acoustic emission
能量特征
centrifugal pumps
cavitation
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Summary:为了探究离心泵空化状态下声发射信号的频率分布特征及其变化规律,该文采用小波分析方法对离心泵空化试验过程中不同空化状态下的声发射信号进行了能量特征提取,研究了不同频段内声发射信号的能量特征随离心泵汽蚀余量变化的关系。试验分析结果表明,在离心泵的空化现象尚未出现以及不同的发展阶段,离心泵进、出口处声发射信号的全频段和各分频段绝对能量和相对能量的变化具有各不相同的特点。〉31.25~62.5、〉62.5~125和〉125~250 k Hz这3个分频段的绝对能量随空化状态改变而变化明显,且变化趋势与全频段的变化趋势类似。〉31.25~62.5 k Hz分频段的相对能量在空化状态变化过程中基本保持不变,而〉62.5~125和〉125~250 k Hz分频段的相对能量变化更为明显。研究结果可为离心泵空化状态的判别提供技术参考。
Bibliography:centrifugal pumps;cavitation;wavelet analysis;acoustic emission;energy features
11-2047/S
Liu Zhong, Zou Shuyun, Li Zhipeng, Ju Wei （School of Energy and Power Engineering, Changsha University of Science and Technology, Changsha 410114, China）
With the development of Acoustic Emission （AE） techniques, researches on the AE signals emitted during the cavitation process to judge whether the cavitation has occurred or not and its development degrees are getting more and more attentions. However, the frequency distribution features and their variation laws with the cavitation states of centrifugal pumps remain to be further studied. In this paper, the wavelet energy features of the AE signals under the cavitation conditions of a centrifugal pump were extracted with the wavelet analysis method, and the variation laws of these features were also revealed. Firstly, the cavitation processes of the centrifugal pump with constant flows and constant speeds at the 60%, 100%and 120%rated flow respectively were simulated on an
ISSN:1002-6819
DOI:10.3969/j.issn.1002-6819.2015.08.015