報告書番号

284067

タイトル（和文）

黒部川第３発電所における水車軸のＡＥおよび振動計測─交換水車軸における結果─

タイトル（英文）

ACOUSTIC EMISSION MONITORING OF THE MAIN SHAFT IN A HYDROELECTRIC POWER PLANT

概要 （図表や脚注は「報告書全文」に掲載しております）

近年，水力発電所水車軸の表面に亀裂発生が定検時に認められるものがあった。この亀裂の発生原因を調べるとともに対策手法を検討するための研究を行なった。この研究はＡＥ法の特徴を利用し，非破壊的に水車軸の亀裂を早期に検出できるか否かを検討し，ＡＥ法の適用性を調べるものである。現地計測は水車軸交換前後に実施し，交換によるＡＥ特性の変化を調べた。ここで，水車軸に直接取付けたＡＥ交換子からの信号は無線で送信し，復調後他の通常のＡＥ信号と同様に処理した。ＡＥパラメータとしては，ＲＭＳ電圧，波形と周波数特性，平均振幅を使用し，さらに振動特性を調べるとともに，ＡＥ信号の発生位相，到着時間差分布を調べ，信号発生源の推定ならびにＡＥ法の適用性を検討した。

概要 （英文）

THE MAIN SHAFTS OF WATER POWER HAVE BEEN SUBJECT TO CRACKS ON THE SURFACE. IN MANY CASES THE CRACKS ARE SITUATED NEARLY AT RIGHT ANGLES TO THE AXIS OF THE SHAFT AND AT LOCATION SUCH AS KEYWAY,RUNNER FITTING PARTS,ETC. WHERE STRESS CONCENTRATION IS INCREASED. TO ESTABLISH APPROPRIATE COUNTERMEASURES AGAINST THOSE CRACKS, TESTS TO COMPREHEND THE CONDITION OF THOSE CRACKS AND TO MONITOR THE MAIN SHAFT BY ACOUSTIC EMISSION(AE)METHOD WERE CONDUCTED. THIS REPORT PRESENTS THE RESULTS OF AE MONITORING THE MAIN SHAFT BEFORE AND AFTER THE EXCHANGE OF THE SHAFT AT A PLANT. AE SENSORS WERE PUT ON THE SHAFT SURFACE DIRECTLY AND ON THE BEARING METALS OF THE SHAFT, AND THE RESONANT FREQUENCY OF THE SENSOR IS 1MHZ. THE SIGNAL FROM THE FORMER WAS CARRIED BY WIRELESS. ALL SIGNALS WERE RECORDED IN THE POWER STATION SITE, AND THEN THE AE DATA WERE ANALYZED IN OUR LABORATORY. AE PARAMETERS USED WERE RMS,WAVEFORM AND FREQUENCY, AND PEAK AMPLITUDE, AND ALSO VIBRATION WERE MEASURED AT THE SAME TIME. INVESTIGATING THE EMISSION PHASE OF BURST SIGNALS AND THE DISTRIBUTION OF THE ARRIVAL TIME, THE APPLICABILITY OF AE METHOD TO HYDROTURBINE SHAFT WAS DISCUSSED.

報告者

キーワード