What did GE's analytics software find?
On January 19th, the GE SmartSignal solution detected erratic changes to IP and HP drum conductivity. IP drum conductivity increased from 11 to 35 (UMHO), while HP drum conductivity fluctuated from 10 to 20 (UMHO). GE’s Industrial Performance & Reliability Center (IPRC) reported the issue to the customer for discussion on the weekly monitoring report.
What was the underlying cause?
Upon investigation, the customer learned that the phosphate injection check valve was installed backwards, and the chemistry analyzer required calibration. The customer replaced the phosphate injection valve, returning chemistry parameters to normal.
What was the value to the customer?
Phosphate and sodium hydroxide (NaOH) treatments in the boiler/HRSG evaporator can lead to numerous operating and corrosive situations if not applied optimally. If the condition had persisted, it would have increased corrosive impurities, which could have resulted in steam turbine depositions and stress corrosion cracking in the superheaters and steam turbine. The warning from GE SmartSignal and the IPRC allowed the customer to correct the issue, preventing undue maintenance and cost if the condition were allowed to continue for an extended period of time.
IP drum conductivity increased from 11 to 35 (UMHO) while HP drum conductivity fluctuated from 10 to 20 (UMHO). The customer replaced the phosphate injection valve, and chemistry parameters returned to normal on Jan 22nd.