What are the most common failures of Hydro Power Plants?
1. Decreased output Under the condition that the head is unchanged, the guide vane opening pointer has reached the no-load opening, and the unit speed has not reached the rated speed or exceeded the original opening value, confirming the unit output decline. The reasons are: ① the volume loss of the turbine (loss of flow). ②The hydraulic loss of the turbine. ③The mechanical loss of the turbine. There are four treatment methods: (1) In the operation or shutdown of the unit, ensure that the depth of the submerged pipe is not less than 300 mm (except for impact turbines). (2) Pay attention to the inflow and outflow conditions to keep the water flow smooth and smooth. (3) Keep the runner running in a normal state, and stop and check if noise is found. (4) For axial-flow fixed-turbine turbines, if the output of the unit suddenly drops and the vibration increases, the machine should be immediately shut down for inspection. =, The shaft temperature rises sharply. 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.
