What did GE's analytics software find?
On January 7, the GE SmartSignal software detected hydrogen purity rapidly decreasing on a hydrogen-cooled generator. The purity decreased from 99% to 95% in fewer than five hours. This 95% reading was 4% lower than model estimates. Due to the rapidly degrading trend, GE’s Industrial Performance & Reliability Center (IPRC) sent a high priority notification to the customer.
What was the underlying cause?
The customer learned that the generator gas bottles were replaced with bottles containing hydrogen blended with argon instead of those containing compressed hydrogen. The customer corrected the type of hydrogen bottles in service, and the purity began to rise shortly afterwards. Purity reached approximately 98% when the customer shut down for an outage on February 6.
What was the value to the customer?
Early notification from the GE SmartSignal solution and the Industrial Performance & Reliability Center provided the customer an opportunity to replace the hydrogen bottles before a purge or a trip occurred. A purge may have reduced the cooling capacity on the generator, and an unplanned trip places undue risk and resource constraints on plant personnel. The IPRC was able to help the customer verify that its maintenance action was successful by showing that actual values began to trend upward and continued to improve over several weeks.
The purity decreased from 99% to 95% in fewer than five hours. This 95% reading was 4% lower than model estimates. After the customer corrected the type of hydrogen bottles in service, the purity began to trend upward towards the model estimate.