Utility Saves ~$300K in Fuel Costs Annually by Using Cycle Isolation Monitoring Software

Overview

For some time, Santee Cooper has been proactive in tracking cycle isolation issues, performing regular walk-downs and measuring temperatures downstream of valves. GSE Engineering, Programs and Performance (formerly True North Consulting) enhanced Santee Cooper’s cycle isolation program by providing a method to prioritize the identified leakage, enabling them to make cost-effective maintenance decisions.

Challenge

As with many utilities that track cycle isolation, Santee Cooper could not estimate the impact of an identified leaking valve. This problem resulted in the misplacement of limited maintenance resources since their decisions were based on incomplete information. Santee Cooper needed a method to estimate the valve leakage flows and heatrate effect.

If the right information could be provided and considered with the fuel costs, the leaking valves could be ranked from worst to least impact and a return on investment for valve maintenance could be established.

Solution

Santee Cooper selected Cross Unit 1 to implement GSE’s TSM Enterprise CIM software for Cross Unit 1, a 1,000° F/1,000° F 2,400 psig reheat coal unit rated at 605 MWe gross plant.

TSM Enterprise CIM, a cycle isolation monitoring tool, compliments Santee Cooper’s existing program by estimating the impact on plant cycle performance. TSM Enterprise CIM automatically prioritizes the leaking valves to justify repair or replacement.

Santee Cooper performs walk-downs at Cross 1, taking downstream temperature measurements at specific locations, to obtain consistent results using the TSM Enterprise CIM calculations.

Each measurement is recorded using TSM Enterprise CIM then convenient forms are provided to track valve conditions information and maintenance history. Graphing capabilities are used to trend value temperature and heatrate import.

Results

Using the TSM Enterprise CIM software, Santee Cooper has identified, prioritized and repaired several leaking drain valves on Cross 1 worth approximately 147 Btu/kW-hr (worth well over $300,000 annually, depending on fuel costs). In addition, they have recently implemented this tool at the remaining three Cross Station units with similar results.

Establishing a valve monitoring program for regularly tracking leakage in power plants is rewarding. Using TSM Enterprise CIM with the site’s cycle isolation program enables significant cost savings from repairing and replacing high-energy valves. Knowing which valves to fix is crucial when resources are limited.

Finding leaking valves in a timely manner with the right tool leads to cost-effective maintenance decisions — critical in today’s power industry.

GSE is committed to providing the best tools and experience available to improve a plant’s bottom line, whether it is lower fuel costs or increased power output.