Best Practices – Tracy

ACC gearbox oil removal piping

Best Practices - Tracy

Frank A Tracy Generating Station 

NV Energy Inc 

1020-MW power facility located near Reno, Nev. Site has 12 generating units including a 580-MW, gas-fired, 2 x 1 combined cycle and four dual-fuel peaking units totaling 170 MW.

Regional plant director: Wade Barcellos

Challenge. The combined cycle at Tracy has an air-cooled condenser with 30 fans. Each fan has a gearbox that requires routine oil change outs (13 gallons) every 5000 operating hours as part of the preventive maintenance program. The fan assemblies are located up eight flights of stairs, 60 ft above the ground. Managing the used oil can be a hassle that requires many additional trips up and down the stairs, and carries a spill risk that could impact the environment.

Solution. Rick Davis, mechanical maintenance planner, developed a piping scheme to eliminate this issue. His installation allows personnel to pour the used oil into a funnel on the fan deck that is piped to a tote on the ground located on a containment pad (Figs 1, 2). When the tote fills, it can be quickly hauled away and replaced with a new one. This arrangement enhances safety by minimizing trips up and down stairs. It also minimizes the risk of spills. Finally, it decreases the “wrench turning” time of personnel assigned to complete this task.

Best Practices - Tracy - 1,2 Best Practices - Tracy - 3 est Practices - Tracy - 4

Results. The last round of oil change outs was completed using this new installation, and the feedback from maintenance personnel was very positive.

Project participants

Rick Davis, mechanical maintenance planner

 

GT hazardous-gas monitor access mod

Challenge. The GE 7FA combustion turbine has two exhaust ducts located on the roof of the turbine compartment. Each duct has two hazardous-gas detectors to protect against flammable atmospheres within the compartment.

These monitors require routine maintenance and calibration to properly function. The original design limited access to the monitors through the inside of the compartment. When access is required, the turbine would have to be brought off-line and cooled so that scaffolding could be built inside the compartment. This process could add several days to a forced or planned outage, depending on the circumstances.

Solution. Kevin Steelman, ICE foreman, devised a way to remove these monitors from the outside of the duct rather than from the inside. Kevin designed a chassis to carry and support the monitor so that could be inserted and removed to gain immediate access. Plant engineering provided assembly drawings (Fig 3) and the new assembly was installed during a HGP outage at the end of 2011.

Results. This new arrangement allows immediate access to the monitors (Fig 4). If a monitor fails (which will trip the unit if the other monitor also has failed), the monitor can be replaced or calibrated in a matter of minutes, rather than days as with the previous arrangement. With a base-load facility such as Tracy, such a time savings is very impactful on our operating availability.

Project participants: 

Kevin Steelman, IC&E foreman