What did GE's analytics software find?
On March 9th, the GE SmartSignal solution detected an increase in the turbine bearing #2 inner barrel tunnel temperature on a gas turbine. After returning to service following a normal shutdown, the temperature increased to 260°F (126°C) and then to 306°F (152°C) vs. an expected value of 250°F (121°C). GE’s Industrial Performance & Reliability Center (IPRC) reported the issue to the customer for discussion on the weekly monitoring call.
What was the underlying cause?
After shutting down the unit, the customer found that gaps had formed in the insulation around the inner barrel, causing the increased temperatures. The gaps were filled in with additional insulation. In addition, the site cleaned the suction filter for the bearing #2 cooling air fan before the last start. These filters were then proactively cleaned for all of the customer’s gas turbines. The site is also planning a review of the frequency of their preventative filter cleaning maintenance activities.
What was the value to the customer?
After being notified by GE's IPRC, the site was able to proactively schedule an inspection of the gas turbine inner barrel area and an inspection of the cooling system. If the condition in the turbine inner barrel was not addressed, it would have resulted in overheating damage to the bearing, possible fire, and/or a trip of the gas turbine.
Turbine bearing #2 tunnel temperature increased to as high as 306°F (152°C) (blue) versus expected values of 250°F (121°C) (green).