Support bearing abnormal oil temperature rise

2020 - support bearing abnormal oil temperature rise 10 - 18 hong-li wang, fault phenomena of zhejiang two millions of unit in one power plant, production of about a year later, there is a preheater support bearing lubricating oil temperature monitoring abnormal oil temperature rise, up to 67. 5 degrees, the other three sets of air preheater support about 19 - bearing oil temperature is higher 21 degrees. And there is no decline, drive motor running current is normal. Installed capacity, equipment and the factory into two units of 1000 mw unit, a single boiler with two rotary preheater, wind, smoke flow, the hot end of the upper and lower part of the cold end, flue gas inlet temperature of about 370 degrees, outlet temperature of about 125 degrees, air preheating ware no. 34. 5, to the problem has been running more than a year. Air preheater is three points warehouse center drive type ( On the drive) , support bearing plant type 294/800 FAG, lubrication method using the circulation, lubrication oil bath type, lubricating oil is heavy load industrial gear oil, label: N680, about 320 l single support bearing oiling. 3, 1, due to the bearing problems cause analysis take the circulation lubrication oil bath type, usually runtime lubricating oil temperature is about environment temperature + 15 degrees or so, and changes with the seasons have different, generally two level set oil temperature alarm, 55 degrees, 65 degrees for overtemperature alarm, the alarm problem with one of the support bearings. 2, check the bearing running noise, use to listen to the bar examination without exception; Lubricating oil level check is normal; Lubricating oil sample taken without exception. From the two tests can't determine whether bearing damage. 3, using infrared temperature measuring gun check by preheater internal conduction heat: support near the bearing temperature about 40 degrees, bearing box cover to the air seal cover between short axial temperature of about 43 degrees, which can determine the oil temperature rise higher than by air preheater internal conduction. 4, the scene does not have heat transfer caused by three ways lubricating oil temperature, bearing box inside also does not have to produce hot conditions. Problem analysis is complicated, to view the drawings for help. From preheater under short shaft and the bearing connection way, through the package number 2 the preheater rotor rotation is passed to the support shaft, rotor, connection and bearing the connection between the way as the smooth plane contact. Thus ignores the there is a way to produce heat, the friction heat production, between two smooth contact area, if the friction heat, so to find like see the light of the problem. Four, processing 1, were allowed in the unit operation, open the bearing box cover, visual lube and bearing rollers without exception, short under the rotor shaft and connecting seat, rolling element bearing on marking. 12 hours under short axis and the connection seat move about 137 mm, connection and the bearing displacement about 13 mm, the data can be seen between sliding. 2, during the unit after mediation, jacking rotor and drag the bearing box, found short axis under the connection with burn marks, and the connection factory besmear antirust paint is not clear. 3, disassembly support bearing mechanism, in accordance with the original process installation, replenish ourselves lubricating oil, lubricating oil temperature after the equipment operation is normal, this problem is solved.