Aero Best Practices highlight LM6000 users-only session at WTUI 2017

The Western Turbine Users and CCJ announced their collaboration on a Best Practices program for aero owner/operators at WTUI’s 26th annual meeting in Palm Springs, March 2016. Goal: Recognize the valuable contributions made by plant staff—and headquarters engineering and asset-management personnel—to improve the performance and safety of generating facilities powered by aeroderivative gas turbines.

Recipients of the program’s first awards were acknowledged at the organization’s 2017 conference in Las Vegas, during the LM6000 breakout’s users-only session chaired by Calpine Corp’s Andrew Gundershaug. Vibrant discussion of seven Best Practices went on for more than an hour.

Looking ahead to the 2018 meeting in Palm Springs, Best Practices entries must be submitted by January 31 for consideration by the judges. Today is not too early. The program is coordinated by VP Ed Jackson for WTUI and Senior Editor Scott Schwieger for CCJ.

Keep in mind that Best Practices aligned with the following subject areas generally attract greatest interest from users:

      • Fast starts/flexible operation.

      • New skills/workforce development.

      • Safety.

      • Outage management.

      • Performance improvements.

      • O&M electrical: Generators, transformers, HV equipment.

      • O&M mechanical: Major equipment, balance of plant.

      • Predictive analytics/M&D centers.

      • Control systems.

In the 2017 Best Practices judging, Riverside Energy Resource Center was the only plant to earn Best of the Best honors—for two years of intense staff effort to reduce startup NOx by 30% without buying a packaged vendor solution costing six or seven figures. Riverside Public Utilities’ Chuck Casey and Brian Atkisson, well known to WTUI members, submitted the entry, which is of value to owner/operators of virtually all types and models of gas turbines.

Interestingly, the Turbine Inlet Cooling Association announced at the WTUI’s Tuesday luncheon that the Riverside Energy Resource Center also was the recipient of TICA’s annual Excellence Award for the plant’s turbine inlet cooling system. It extracts an additional 66 MW from the facility’s four LM6000PC gas turbines when summertime temperatures get into the triple digits.

All of the 2017 Aero Best Practices Awards went to LM6000 plants except for the last one in the string below, which was received by Waterside Power LLC, a TM2500 in Connecticut. Thumbnails of the Best Practices follow; additional details will be available in CCJ’s 1Q/2017 WTUI special editorial section, coming soon.

Edgewood Energy LLC

Challenge: Failure-prone regulator (internal diaphragm rupture) serving the SPRINT water injection system.

Result: Unexpected unit trips caused by loss of emissions control or high exhaust-gas temperature, adversely impacting availability.

RCA revealed high-pressure regulator discharge too close to the suction of the low-pressure valve, reducing lifetime of valve seats and diaphragms (annual repairs were about $10K, not including availability loss).

Alternative solutions: Redesign skid piping to separate regulator and valve, or find a valve capable of accommodating existing site conditions.

Path chosen, and the least-cost option, was to buy more suitable valves (Straval Machine Co).

Terry Bundy Generating Station

Challenge: Improve plant heat rate. Goal: 1% improvement. Facility has an LM6000 peaker, a 2 × 1 combined cycle, and three landfill-gas-fired recips.

Process:

      • Identify all equipment impacting heat rate and develop baseline operating factors.

      • Assure proper monitoring and data retention.

      • Determine deviation from baseline and method/cost of correction.

      • Develop procedures for periodic review of performance metrics.

Action planned/partial results:

      • Replace station lighting with LED. Saves 46 MWh/year, reduces peak demand by 3.9 kW. Cost: $8200.

      • Upgrade air compressor. Saves 214 MWh/year, reduces peak demand by 24 kW. Cost: $45,000.

      • Improve plant monitoring and reporting capabilities by replacing Wonderware historian with PI. Cost $216,000.

      • Add pre-circulation system to GT chiller to reduce spikes in chiller loading on startup. Cost: $34,000.

Project planned for completion in 2017. Expectation is that results will be shared at the 2018 WTUI conference.

Orange Cogeneration Facility

Challenge: Backfit safety improvements at a 20-year-old 2 × 1 combined-cycle cogeneration plant, including:

      • Facilitate access to the plant’s two oily water separators for maintenance and cleaning.

      • Improve fall protection for yearly maintenance.

Improvements:

      • Increase the size of the access hatch for the 13-ft-deep sump to facilitate removal of filter elements for cleaning. Maintenance now takes half the time it did previously. A section of grating was added to the sump lid to allow inspection during routine rounds.

      • Fall protection was enhanced by removable handrails and installation of staff-designed davit arms capable of rotating 360 deg.

Exira Station

Ventilation-fan flow switches

Challenge: Unreliable flow indication from package-fan flow switches.

Solution: Use real-time current monitoring from fan motors to indicate flow.

Additional benefit: Provides diagnostics to verify positive flow and indicate how well the motor is running.

Package heater auto controls

Challenge: Frequent heater maintenance.

Reason: Heater was not designed to operate when the package fan was running. This caused short-cycling when the fans were on. Plus, the volume of air flow through the package overwhelmed heaters when the fans were operating; warm air was discharged to atmosphere.

Solution: Automated the heaters to shut off when a fan is on—easily done by existing MCC hardware.

Lawrence Generating Station and Worthington Generation LLC

Challenge: Shift lineups at these two multi-unit peaking stations mandated single-person operational staffing for several hours each day and on weekends—an obvious safety concern.

Solution:

      • Each operator has a smartphone and downloads the ManDown™ app to his or her device.

      • Each operator verifies he or she has an “In case of emergency” ID.

      • Work that can be performed during single-person operation is specified based on job- and site-hazard analyses conducted by plant staffs.

      • Work schedules were modified to minimize the amount of single-person operating time.

Benefits:

      • ManDown app activates a 1-min safety timer which sounds an alarm if the phone is still for 30 seconds. If operator is unable to stop the alarm by moving the phone, an automatic text message is generated and recipient generates emergency procedures. While ManDown does not increase “safety,” it does improve response time.

      • Work-schedule change reduced maintenance overtime hours slightly in cases where the task required two people and only one operator was onsite and not allowed to do the work.

Waterside Power LLC

Background: The emergency fast-start (30 minutes to dispatch) oil-fired peaking plant has three legacy TM2500s and is manned by a staff of three, including the plant manager—down from five only a couple of years ago. The staff reduction limited the amount of time operators could be outside the control room.

Challenge: The demin-water system required a manual start, conductivity was monitored locally at the mixed-bed trailer, filling of the storage tank was a manual operation. Treated water was wasted occasionally by overfilling the tank.

Goal: Keep the operator in the control room during all dispatches to assure high availability and minimize downtime.

Solution: Installation of an Ethernet cable and level transmitter allowed the on-shift operator to view in the control room the storage-tank level and demin-water conductivity, and verify the position of the mixed-bed inlet valve.

Benefits: Operator time away from the control room is dramatically reduced during dispatch, treated water is conserved (no more spills), water-quality excursions are prevented. Plant continues to meet all dispatch requirements with a performance factor exceeding 99.85%.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          

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