Best Practices – Osprey

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Best Practices Award

Challenge. In order to reap the benefits of favorable grid economics, Osprey Energy Center improved its cold-start performance to ensure 40-min starts. Site personnel investigated the possibility of a 40-min ramp cycle (0-250 MW) for a combined-cycle unit and explored the timing requirements and key steps to achieve a fully blended and ready-for-market response status.

Solution. Plant staff reviewed HRSG heat-up rate restrictions as well as steam-turbine (ST) warmup restrictions and worked with the OEMs to optimize the startup process to bring the plant from shutdown status to a 2 x 1 ready for all market calls within a 40-min window. By bringing indication of HRSG drum heat-up rates to the DCS, and optimizing ST starting logic, the site was able to achieve its first 40-min 2 x 1 ramp in March 2012.

During the March start, a demonstration of operator manual control requirements lead to the addition of a split-range HP-to-auxiliary steam letdown control valve to reduce the operator commitment to maintaining steam header pressure. The addition of split-range control permitted the operator to focus on plant response to operational requirements and allowed for smoother control of auxiliary header pressure (air ejectors).

Results. Successful and reliable cold starts from 0 to 2 x 1 ramp in 40 minutes.

Project participants: 

The entire Osprey plant staff

Seasonal readiness refresher training

Challenge. By providing preseason refresher training on systems, industry and company lessons learned, and improving system indications, O&M personnel have a renewed level of knowledge on systems that are infrequently operated.

Solution. Preseason refresher training on heat tracing and freeze protection renews O&M staff level of knowledge in advance of any cold weather. By the inclusion of system and theoretical basics into lesson plans, trainees renew their level of knowledge from the ground up. Having this training as an interactive session with the participants, and not solely a lecture, maintains a high level of involvement.

The addition of indications in the heat-trace system, including panel schedules on controllers as well as “per phase” load indications give the operator information on which lines are protected and how the protection system is functioning.

Results. The plant has experienced zero heat-trace-related failures since program implementation.

Project participants: 

Steven Smith, plant manager

Gil Kaelin, maintenance manager