水車の劣化診断方法と対策に関する調査

カテゴリ: 技術報告

論文No: 1022

グループ名: 【B】電力・エネルギー部門

発行日: 2005/06/15

タイトル(英語): Diagnosis Methods and Countermeasures against Deterioration of Hydro-turbines

著者名: 水車の劣化診断方法と対策に関する調査専門委員会

著者名(英語): Technical Committee of Survey on Diagnosis Methods and Countermeasures against Deterioration of Hydro-turbines

要約(日本語): 電力需要の伸びの鈍化や自由化を背景に，水力発電設備は，信頼度を維持しつつ，一層の延命化・点検の合理化が求められている。そのため，水力発電機器の分解点検・修理周期の延伸を目的とし，従来の定周期で計画する時間基準予防保全(TBM)から，機器状態を把握し計画する状態基準予防保全(CBM)へ移行してきている。CBMの導入にあたり，部品の劣化を的確に把握し評価することが重要であり，共通した診断方法および判断指標の確立が必要となってきている。 そこで，本委員会では，水車部品の劣化や欠陥の事例と，それらの診断方法の調査に加え，材料強度限界，性能・機能限界，修理限界について検討し，水車部品の劣化診断方法および劣化判断指標の明確化を図った。同時に，最新の外部診断技術，延命化対策を調査し，今後の保守の資となるよう取りまとめた。 本報告書は、以下の項目を中心に構成されている。 ①水車の現状調査（点検周期と内容，取替・修理基準，劣化部品と部位，侵食・壊食・腐食事例，き裂・障害事例），②水車部品の取替・修理判断方法（部品の取替・修理指標，損傷量の測定管理方法，非破壊検査，外部診断技術），③水車の延命化対策（溶接修理，コーティング，材質改善，最適化設計，き裂進展防止対策）

要約(英語): Against the background of slowing power demand growth and progressing market liberalization, the longer durability and more reasonable maintenance are required for equipment in hydropower plants. Thus, with an aim to elongate the frequency of inspections, which involve disassembling and repairing equipment, the maintenance work has been changing from the traditional Time Based Preventive Maintenance (TBM), wherein inspections are planned on the periodical basis, to the new Condition Based Preventive Maintenance (CBM), wherein inspections are planned on the basis of the condition of equipment. For the introduction of CBM, however, as it is necessary to accurately assess the deterioration condition of parts and the materials condition of equipment ,the standardizing diagnosis methods and criteria has been required. For this purpose, this committee surveyed cases of deterioration and defects in parts and materials of hydro-turbines concerning the diagnosis methods and marginal strength of materials as well as performance and repair timing in order to clarify the diagnosis methods and criteria for hydro-turbines. The committee also surveyed the latest technologies of the external diagnosis devices and the durability extension methods in order to help maintenance work hereafter. This report is mainly composed of the following items. ① Current practices (frequencies and contents of inspections; criteria for repair and replacement; parts and materials subject to deterioration; cases of decay, corrosion, erosion, crack and other troubles) ②Diagnosis methods for repair and replacement of parts and materials of hydro-turbines (criteria for repair and replacement; measurement and control of material wear and loss; nondestructive testing; external diagnosis technologies) ③ Durability extension methods for hydro-turbines (welding; coating; improving materials; optimal design; preventive measures against crack development)

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