CAJ | 학술논문

管道系统的微小泄漏会影响瞬变压力波的波形和衰减特性。用Flowmaster流体仿真软件建立了管道模型，控制阀门小开度快速关闭，使管道内部产生瞬变流动，用短时傅里叶变换对管道泄漏发生前后的压力波信号进行时频分析，提取出前三次谐波分量的归一化幅值，通过指数拟合得到有无泄漏时各谐波分量幅值的衰减率，计算不同谐波分量泄漏衰减率的比值对管道泄漏进行定位。结果表明，用该方法提取的谐波分量可以准确地计算出各次谐波的衰减率，从而提高了泄漏的定位精度并能够检测到0.17%的微小泄漏。
관도계통적미소설루회영향순변압력파적파형화쇠감특성。용Flowmaster류체방진연건건립료관도모형，공제벌문소개도쾌속관폐，사관도내부산생순변류동，용단시부리협변환대관도설루발생전후적압력파신호진행시빈분석，제취출전삼차해파분량적귀일화폭치，통과지수의합득도유무설루시각해파분량폭치적쇠감솔，계산불동해파분량설루쇠감솔적비치대관도설루진행정위。결과표명，용해방법제취적해파분량가이준학지계산출각차해파적쇠감솔，종이제고료설루적정위정도병능구검측도0.17%적미소설루。
The minor leaks of pipeline system will affect transient waveforms and its attenuation characteristics. A pipe-line model is built by using fluid simulation software Flowmaster. Short-time Fourier transform is used to analyze the pres-sure signals in time-frequency domain, which are generated by closing the valve partially in a short time for both leak and no-leak case. Damping factors of the first three harmonic components extracted from the time-frequency analysis results are calculated by exponential fitting. The leak position is obtained by calculating the ratios of leak-induced damping rates. The results show that the harmonic components extracted from the time-frequency analysis results can be used to exactly calculate the damping rates, which can improve the accuracy of leak location. The leakage can be as small as 0.17%.