What did GE's analytics software find?
On March 9th, the GE SmartSignal solution detected an increase in the IP drum level control valve demand. The valves increased from 48% to 54%. At the same time a decrease was noted on the IP feedwater pressure along with an increase in IP feedwater flow. GE’s Industrial Performance and Reliability Center (IPRC) reported the issue to the customer for discussion on the weekly monitoring call.
What was the underlying cause?
Upon investigation, the IP intermittent blowdown isolation valve was found open. Once the valve was closed, the IP feedwater flow decreased from 65 ton/hr to 53 ton/hr.
What was the value to the customer?
When blowdowns/drain valves leak or get left open, HRSG efficiency is affected. In this case, a 0.5% efficiency loss was estimated to the IP section of the HRSG. Due to the early notification from the IPRC, the customer saw an increase in HRSG efficiency and a decrease in feedwater usage.
IP feedwater flow increased as IP feedwater pressure decreased (blue) versus model estimates (green).