离心泵空化状态与声发射信号特征关系试验

Experiment on Relationships between Centrifugal Pump Cavitation Conditions and Acoustic Emission Signal Characteristics

为了获得离心泵空化状态下声发射信号的变化规律，在离心泵空化试验基础上，采用声发射技术采集并分析了离心泵不同空化状态下的声发射信号，提取了声发射信号的事件计数、振铃计数、频率中心和有效电压值等4种典型特征参数，分析了这些参数随离心泵汽蚀余量变化的对应关系。研究表明，在空化未发生、刚发生和已完全形成等不同阶段，这些典型特征参数变化具有明显特点，先有少许波动，然后有较大幅度的增加或减少，再呈现较大幅度的减少或增加的趋势。这一规律可作为采用声发射技术辨识离心泵空化状态的技术依据。

In order to obtain the variation law of the acoustic emission signals under the centrifugal pump＇s cavitation states, the research was based on the centrifugal pump cavitation test. The acoustic emission technology was adopted to collect and analyze the acoustic emission signals. Four typical features were extracted, i.e. event count, ringing count, frequency eentroid and root mean square. Their relationships with the net positive suction heads of the centrifugal pump were analyzed in detail. The results show that these typical characteristic parameters change obviously under different stages such as before the occurrence of cavitation, cavitation first appearing and cavitation being fully developed. They firstly fluctuate a little, then increase or decrease substantially, and then there are large reducing or increasing trends respectively. This law can be used as a technical basis for identifying the cavitation conditions of centrifugal pumps with the acoustic emission technique.