First, if the temperature of the water guide shoe of the Hydraulic Turbine Generator rises slowly, and the unit swing and vibration are not abnormal, do not stop it in a hurry. First check whether its temperature measurement system is normal, whether the flow rate and pressure of the cooling water are normal, and whether the oil level is normal. If the cause cannot be quickly determined and the temperature continues to rise, it is necessary to shut down and check immediately.
Second, if the temperature suddenly rises, the vibration and swing of the unit will suddenly increase, and an emergency shutdown is required immediately. Thoroughly check the cooling water system, temperature measurement system, oil level, oil quality, and oil and water pipelines of the water guide groove to find the cause. If necessary, the water guide can be disassembled to check the wear between the surface of the water guide tile and the gap, and repair it reasonably.
First, if the crew has overspeed, don't panic, stay calm and respond calmly.
Second, if the load is suddenly lost during the operation of the unit, check whether the over-speed protection device can operate normally. If the over-speed protection action is abnormal or refuses to operate, an emergency shutdown must be performed manually immediately, and the main valve of the turbine can be closed if necessary.
Thirdly, if during the start-up and shutdown process, the Hydro Turbine Runner's governor is abnormal or the shear pin is cut, causing the unit to rotate too fast. At this time, even though the speed has not reached the rated value of the overspeed protection operation, the main valve of the turbine needs to be closed immediately. For those units without a main valve, the inlet gate in front of the unit needs to be closed immediately. In addition, if the unit's speed drops below 35% of the rated speed, manual braking is required. So that the unit is completely shut down. For those units without a main valve, the inlet gate in front of the unit needs to be closed immediately. In addition, if the unit's speed drops below 35% of the rated speed, manual braking is required. So that the unit is completely shut down.
First, the main fault of the runner is cavitation. In the process of welding repair and cleaning the cavitation, manual arc welding is generally adopted. Before electric welding, the cavitation should be scraped clean, and then the burrs and high points should be ground off, and then preheated with an oxygen-acetylene flame at a temperature of about 200°C.
Second, with the water-dividing blade as the boundary, the cavitation is divided into upper and lower parts for surfacing. Use back repair welding to finish the surfacing of the upper part, and then surfacing the lower part. In addition, the blade shape must be strictly checked during welding, carefully proofread and corrected. In order to ensure that the requirements of welding conditions can be met, so as to achieve the purpose of improving the corrosion resistance of the runner.