Failure analysis of induced draft fan used in a thermal power plant using coordinated condition monitoring approach: A case study

Abstract

Early detection of the fault is not only essential to ensure the current health of the critical equipment but also to diagnose the fault before any catastrophic failure. In order to improve the capability for early fault detection and diagnosis of critical equipment, an improved form of generalized coordinated condition monitoring approach has been developed and adopted in this paper. The effectiveness of an integrated approach has been realized by concurrently using selected condition monitoring techniques viz. vibration analysis, noise measurement, wear debris analysis, ultrasonic monitoring in terms of increased fault diagnosis accuracy. A case study on failure analysis of Induced Draft (ID) fan 2A from 250 × 2 MW thermal power plant located in the western region of India is carried out. The vibration trend of acceleration parameter of hydraulic coupling input bearing found to be on the higher side and reached to 4.2 (g) level, sound level meter recorded an increased noise level of 99.8 dB, and high-frequency sound of 18 dB ultrasound was observed by the ultrasonic meter. In addition, medium alloy bearing particles of size 68 µm were found in the test oil sample, which confirmed that hydraulic coupling input bearing deterioration, has occurred.The vibration parameter provides sufficient insights into the earliest failures, and the fault location, severity, its effect on other process parameters are monitored by noise, wear, and ultrasound level. Furthermore, the secondary damages related to motor and fan were avoided. Simultaneous use of these techniques not only detects the earlier fault but can be diagnosed before any catastrophic failure. The result obtained in this study assisted the maintenance engineer of the plant for scheduling the maintenance activity well in advance.