Safety Equipment & Systems – Rokeby Generating Station
Combustor-enclosure safety systems
Rokeby Generating Station
Lincoln Electric System
Opportunity. The site has two Alstom 11N1 combustion turbines with single-silo EV combustors. Both units are dual-fuel capable, with water injection for fuel oil emissions control and power augmentation, which requires a large number of pipe connections in the combustor enclosure.
In addition to the combustor piping maintenance issues, the combustor enclosure’s vent fans, lighting and fire detection systems are in elevated locations, requiring significant preparation and outage time to service.
Finally, we were concerned about the restricted enclosure access that would result from using the OEM’s standard ladder system. An integrated safety program endeavored to address the safety and maintenance efficiency issues associated with the combustor enclosures.
Solution. In order to reduce the operational safety issues and minimize maintenance outage times associated the combustor systems we implemented several enhancements, including:
- Installing steps and landings versus the standard ladder system for combustor access (Fig 13)
- Installing camera systems to remotely monitor the combustor enclosure systems
- Installing a maintenance platform with movable sections to allow easier and quicker access to the upper level combustor systems (Figs 14, 15).
Results. Installation of the access steps and landings were completed as part of the original CT installations. The stairway allows much easier and faster access to the combustor enclosure increasing maintenance efficiency and improving emergency egress/access.
The pan, tilt, zoom camera system was installed to allow operators to remotely monitor enclosure conditions during unit operation, reducing the need to access the combustor enclosure while the unit is running.
The maintenance platform design and installation were completed as the latest phase of the safety program. The platform includes fixed and movable deck sections with integrated fall- protection tie-off systems. The movable sections enable the operator to move to different sections of the enclosure while also allowing for removal of deck sections for combustor maintenance and component removal.
The maintenance platform also significantly reduces the set up time for maintaining upper-level combustor components as well as reducing fall hazards. We estimate an annual reduction of approximately 160 hours of maintenance time associated with the elimination of scaffolding requirements because of the maintenance platform as well as improved access to the combustor via the steps (as opposed to the ladder system).
