Emerson Process Management has successfully replaced existing controls on the Nikiski Generation Plant’s GE Frame 6B gas turbine with its Ovation control technology. This marks one of the few times an outside vendor has been chosen to retrofit Mark VI controls. The plant, owned and operated by Homer Electric Association (HEA), is located southwest of Anchorage, Alaska.
The controls replacement project was part of the first phase of a two-phase initiative to convert the 40-MW, simple-cycle power plant to a 60-MW, combined-cycle facility. The resulting 45 percent increase in generation capacity with a minimal increase in fuel consumption will enable HEA to cost-effectively meet the electricity needs of the Kenai Peninsula. An additional 20-MW capacity is available through the use of duct-firing capability built into the existing HRSG. This brings the total plant capacity to 80-MW, but requires additional fuel consumption.
In addition to replacing the Mark VI turbine controls, Emerson integrated the GE EX2100 excitation system into the new Ovation system, enabling the Ovation system to remotely control its functionality. Emerson also provided a simulation solution, which is used to test and verify control logic, as well as to train operators on the new Ovation system; and a remote dispatch capability that will give HEA greater operational flexibility and efficiency.
“As part of this major effort to convert the plant to a combined-cycle facility, we wanted to take advantage of every opportunity to ensure the plant would operate at peak efficiency for years to come,” said Brad Zubeck, program manager for HEA. “Moving to a single control platform is advantageous for many reasons, among them, the ability to have tighter overall control of plant operations, as well as a clearer view of key plant and turbine parameters.”
Emerson’s comprehensive solution for phase one also included its AMS Suite predictive maintenance software for more efficient management of intelligent field devices, as well as its CSI 6500 Machinery Health Monitor. The CSI 6500 will enable HEA to detect turbine problems before they become critical by delivering comprehensive, real-time information that includes prediction, protection and performance monitoring, all fully integrated with the Ovation control architecture.
With phase one completed and the combustion turbine back in operation, phase two is now under way. Emerson is further expanding the plant’s Ovation system, providing direct control and monitoring of the upgraded heat recovery steam generator (HRSG), burner management system, feedwater and water treatment systems, substation equipment and balance-of-plant processes. The Ovation system will also provide supervisory control of the new steam turbine.
Emerson and HEA are also collaborating on projects at several other plants.
“Our work with HEA is an excellent example of the breadth and depth of our automation and control solutions for the power generation industry,” said Bob Yeager, president of Emerson Process Management’s Power & Water Solutions. “Our decades of industry experience, along with the ability to provide a solution targeted to every aspect of the power generation process, are why customers around the world rely on Emerson.”