Regular maintenance of the boiler desuperheating feedwater pump is an important measure to prevent small defects from turning into major failures, and to create conditions for extending the service life of the pump, improving the integrity of the equipment, and saving energy. Regular maintenance is divided into three types: local overhaul, unit overhaul and extended overhaul.
1. Partial maintenance
It is generally arranged to be carried out in a planned way during the operation gap or winter maintenance period. The main items of partial overhaul are:
1) Inspection and treatment of the copper sleeve and oil sleeve of the desuperheating water pump regulator of the fully-regulated boiler.
2) Inspection of the guide bearing of the centrifugal pump. The wear, water leakage, and journal wear of rubber bearings should be inspected, recorded, and dealt with. Most of the oil guide bearings are babbitt alloy steel bearings, which are soft and easy to wear. For example, if the sealing effect is not good, water enters the oil basin when the machine is stopped, the sediment is deposited, and the bearing and journal are worn during operation. Especially for carbon steel journals that are not spray-plated or inlaid with stainless steel, in order to understand their rust and wear conditions, they should be inspected and treated regularly.
3) Inspection and inspection of thermometers, meters, relay protection devices, etc.
4) Sampling and testing of the oil grooves of the upper and lower guide bearings and the turbine oil.
5) Check the bearing gap and the surface of the bearing bush. According to the temperature of the thermometer during operation, purposely check the bearing gap and the condition of the shaft surface.
6) Check and deal with the brake part.
7) Whether the fasteners of each part of the unit, such as anchor bolts, shaft keys, and positioning pins, are loose.
8) Check the appearance of the oil cooler and pass the water test to see if there is any leakage.
9) Check the cavitation and sand abrasion of the impeller, blades and impeller shell, and measure and record the degree.
10) Measure the gap between the blade and the impeller shell.
2. Unit overhaul
It is a planned management task to restore the technical condition of the unit through overhaul. One of the damage to the unit is accident damage, and the probability of occurrence is very small. The second is normal damage, such as running friction and wear, cavitation damage, and sand abrasion. The probability of occurrence is very small. The third is normal damage, such as vibration caused by various interferences, the effect of AC stress and corrosion, and electrical insulation aging.
3. Extensive overhaul
When the pump room is due to uneven foundation subsidence, the axis of the unit is shifted and the vertical concentricity changes; or the parts are severely worn or damaged, resulting in a serious decline in unit performance and technical and economic indicators, and the whole unit must be disassembled, repeated repairs, and replacements , Adjust and carry out partial transformation.
