A recent 170-megawatt steam turbine loss at a combined cycle power generation facility demonstrates the cost associated with turbine repairs. In this event, one of the 40-inch last-stage blades of the low pressure section of the turbine (L-0) broke, impacting several adjacent blades of the same stage. The turbine tripped due to high vibration, and shut down accordingly.
The cause of the loss remains under investigation. The initial repair estimate is nearly US$3 million and includes the replacement of the blades (accounting for half of the total cost), opening and closing the unit, blade balancing/replacement, diaphragm and coupling alignment, rotor inspection, unit transport and other fees. An extended forced outage is anticipated.