Carrying out detailed internal inspections of gas turbines is critical to any routine power plant maintenance program, but it has to be achieved without affecting production targets. Many companies have tight outage schedules and face the prospect of high penalties for longer than expected equipment downtime.
Against this backdrop, operators of power plants frequently use remote visual inspections of machinery and pipework during brief shutdowns. However, it is argued within the industry that such inspections have limited effectiveness because fiber scope and video scopes used to carry out the work can lack flexibility, and these remote visual inspections may fail to provide accurate condition monitoring, as they are unable to get close enough to potential equipment problems.
Thus,they may not clearly distinguish, for example,whether a mark inside power plant equipment is a crack or just a discoloration.This leaves doubt in the minds of maintenance engineers, who have to decide when to service components.
Kobra is made of two flexible, steerable guides,or sleeves, arranged coaxially. Mechanical controls enable the operators to steer and vary the tension of Kobra, allowing navigation and viewing angles that were otherwise impossible.
Faced with potentially uncertain information gathered during a remote visual inspection, plant operators often decide to carry out an engine strip or component removal rather than risk a potentially disastrous failure or other serious engineering problems such as gas turbine vibration. Engineers at a British company have,however, developed a new flexible, steerable guide tool, which it claimed can carry fiberscopes and videoscopes further and deeper into critical plant and reach areas that may have otherwise needed component removal.
The company behind the new product, which is called Kobra, is QinetiQ