摘要
电站锅炉换热器高压蒸汽管路泄漏的声学监测是故障早期发现的重要手段,对于合理安排维修时间和提高设备的利用率具有十分重要的意义。文中对较小尺度泄漏孔喷流噪声的特性进行了理论分析和实验研究,对实测喷流噪声信号进行了频谱分析和特征提取。分析结果表明,喷流噪声的自相关功率谱密度分布表现出明显的峰值现象,峰值频率随着喷口尺度的增大而降低。对于压力比低于临界压力比的欠膨胀小孔喷流,当喷口尺度从1mm到4mm时,噪声功率谱的峰值Sr数从0.05到0.13,这一特点可用于估计泄漏喷口的尺度。同时,根据高温蒸汽小孔喷流的功率谱分布状态,对信号滤波提出了建议。
Acoustic monitoring of leakage from HP steam pipelines of utility-boiler heat exchangers is an important means for early fault detection and is of major significance for the rational arrangement of maintenance schedule and the enhancement of equipment availability.A theoretical analysis and experimental study were conducted of the jet flow noise from a relatively small leakage hole.A spectrum analysis and characteristics pick-up were performed of the jet flow noise signal actually measured.The analytic results show that the self-correlated power spectrum density distribution of the jet flow noise exhibits an obvious peak-value phenomenon and the peak-value frequency will decrease with an increase of the jet-flow hole diameter.For an under-expanded small hole jet flow at a pressure ratio below the critical one,when the jet-flow hole diameter increases from 1 mm to 4 mm,the peak value of the noise power spectrum Sr number will go up from 0.05 to 0.13.Such a feature can be used to estimate the leakage hole size.In the meanwhile,a proposal has been made for signal-wave filtering on the basis of the power spectrum distribution of high-temperature steam small-hole jet-flows.
出处
《热能动力工程》
EI
CAS
CSCD
北大核心
2008年第3期285-287,共3页
Journal of Engineering for Thermal Energy and Power
