Better blades

A new system that continuously monitors operating blades in gas turbines has surpassed 5,000 hours of operation, confirming that the technology is ready for commercialisation.

Developed by Siemens Power Generation, with funding from the US Department of Energy (DOE), the online monitor makes it possible for operators to replace turbine blades based on their actual condition, when the thermal barrier coating is worn or damaged. This capability optimises the life of the blades, avoids the cost of unscheduled replacement, and extends the time between preventative maintenance periods, increasing the availability of the plant.

The technological breakthrough could help keep electricity rates down by saving gas turbine utility operators an estimated $600 million per year.

The first full-scale high-temperature, full-pressure commercial system was installed in a Westinghouse 501FD gas turbine at Empire Stateline Electrical Company in Joplin, Missouri, during a scheduled outage last October to demonstrate its capabilities in capturing real-time infrared images of rotating blades. Siemens engineers are monitoring the performance of the first row of thermal-barrier-coated blades on both pressure (front) and suction (back) sides.