水力发电厂最常见的故障是什么?
1.在扬程不变的情况下，导叶开度指针已达到空载开度，机组转速未达到额定转速或超过原开度值，确认机组出力下降。原因有:①涡轮的体积损失(流量损失)。②透平的水力损失。③透平的机械损失。处理方法有四种:(1)机组运行或停机时，确保沉管深度不小于300mm(冲击式水轮机除外)。(2)注意入流和出流条件，保持水流顺畅、畅通。(3)保持流道运行正常，如发现噪音，应停机检查。(4)对于轴流固定水轮机组，如果机组出力突然下降，振动增加，应立即停机检查。轴的温度急剧上升。 The turbine bearing has a guide bearing and a thrust bearing. The guide bearing is to prevent the unit from rotating, oscillating or vibrating, and to ensure the stability of the shaft center. Thrust bearing, bearing the axial thrust of the runner. The reasons for its influence on the bearing temperature rise are: poor quality of bearing installation or bearing wear; mismatch of lubricating oil label or deterioration of oil quality; abnormal oil supply of lubricating oil system failure; cooling water system failure and cooling water interruption; other reasons make the unit vibrate. The treatment methods are: (1) For water-lubricated bearings, the lubricating water used must be strictly filtered to ensure the quality of the water. The water must not contain a large amount of sediment and oil, which reduces the wear on the bearings and the aging of rubber. (B) Thin oil lubrication currently generally adopts self-circulation, adopts oil-slip ring and thrust disc, which is rotated by the unit and supplies oil by self-circulation. The self-circulation operation must pay close attention to the working condition of the oil rejection ring, and no jamming is allowed. The oil supply to the thrust disk and the oil level of the oil tank are not allowed. (3) For dry oil lubricated bearings, pay attention to whether the specifications of the dry oil (grease) are consistent with the bearing oil and whether the oil quality is good. Lubricate regularly to ensure that the bearing gap is one third to two fifths. (4) Ensure that the bearings are tight and prevent pressure water and dust from entering the bearings. (5) The installation clearance of the sliding bearing (bearing bush) is related to the unit pressure of the bearing bush, linear rotation speed, lubrication method, oil viscosity, spindle deflection, installation accuracy, allowable vibration and swing of the unit, and cannot be arbitrarily increased or reduced.
