HOW THIS POWERSTATION USED TECHNOLOGY TO OVERCOME THE CHALLENGES IN POWER GENERATION

• 11/03/22
• GRAPES

OVERVIEW

A popular power station approached RDI technologies with two challenges they are facing while power generation. At this Power Station, two Induced Draft (ID) fans are critical to the operation of each 700+ megawatt turbogenerator. Staff had been monitoring a steady increase in axial vibration at the Fan Drive End Bearing of one of Unit 3's two ID Fans.

Over a two-month period, the axial vibration amplitude increased from 1.75 mm/sec RMS to 8.5 mm/sec RMS.  Using traditional vibration analysis techniques, the vibration analysts were experiencing troubles determining the root cause of the increasing trend and noise coming from the coupling. Historically, this type of fault would have been allowed to fail, resulting in a $70k/hour loss of revenue generation for the company.

APPROACH

A leading global consulting firm, ALS Industrial, teamed up with the generator's engineering team to solve the emerging ID Fan problem using RDI's Motion Amplification software. It took less than an hour to get to the ID Fan location in the power station, set up the video camera, and capture several videos. This hour included time to analyse the results, which were all completed in the field.

The videos aided in the identification of several problems, including coupling wear and shaft movement, bearing housing hold down bolt looseness, frame pedestal bolt looseness, and cracked welds between the bearing housing spacer block and fan drive bearing pedestal. The identified coupling, bearing housing, and bearing pedestal issues were resolved during a low load period and a 300MW restriction.

RESULT

• Using RDI's Motion Amplification software, the fault was diagnosed in the field within 1 hour.

• Visualization of the root cause (coupling wear, loose hold down bolts, and failed welds) of the high axial vibration, which had been difficult to identify using traditional vibration analysis techniques.

• Using RDI's Motion Amplification software, the fault was diagnosed in the field within 1 hour.

• During a low-load period, remediation work reduced the high axial vibration at the fan drive end bearing by more than 70%.

• The pump was returned to duty service rather than being placed on standby.

• The solution was implemented during a low load period.