Laser cladding repairing shaft neck caused by shaft vibration signal distortion analysis and diagnosis

Laser cladding repairing shaft neck caused by shaft vibration signal distortion analysis and diagnosis, 2018 - 07 - Author: 23 Qian Rongcai, etc ( Huaneng yuhuan power plant) 1, the introduction of unit saic N1000 - 26. 25/600/600 units. Steam turbine low pressure rotor bearing journal 4 A has 4 weeks to damage, the width of 25 mm respectively, 60 mm, 30 mm, 55 mm, to 2 mm, most rotor material for: nicrmov14-26 5. Using laser cladding of the journal to repair later. 2, abnormal vibration profile shaft neck after repair, the unit started, when I first got to 3000 r/min, the shaft vibration is normal, 4 synthetic value around 50 um, watts vibration of 1 mm/s; About four hours later, the 4 axis vibration signs have climbed, adjust the vacuum with the shaft seal steam, fruit, then the shaft vibration to 250 um, vibration is still 1 mm/s, hits the brake. 3, vibration analysis, 1) Wazhou 4 more than 250 um, and tile is only 1 mm/s, abnormal; ( 2) 4 watts the oil temperature is normal; ( 3) Shaft vibration on adjacent normal; ( 4) 4 shaft vibration climb, double frequency component changed little, little change amplitude and Angle; ( 5) Check thermal measurement circuit, there is no exception; ( 6) 4 shaft vibration frequency components is wide, and given priority to with high frequency. Climb check start data, found that the vibration associated with rotor axial displacement is obvious, the analysis judgment that measuring axial vibration of the eddy current probe with the expansion of the rotor might just fall into the rotor matrix and the junction of cladding area, because of the different material, make the signal distortion. Check drawings, after confirmation. 4, in the operation of the measures to strengthen in 4 tile and its adjacent bearing vibration monitoring; Satellite readjust 4 vibration eddy current probe installation position and avoid the repair area. Suggestion journal restoration of turbine considering eddy current probe to avoid problems. Note: material source: in 2017, hubei, anhui, hebei, jiangsu, zhejiang province steam turbine technology exchange meeting papers.