At the 2024 Ovation Users Conference, Emerson’s Jared Lubbert and Steve Sinka presented Mechanical Upgrades for Turbine Control Retrofits. Here is their presentation abstract.
No turbine control system upgrade is complete without interfacing to the existing field devices, especially those devices that drive the turbine hydraulic or electro-hydraulic control system. This break-out session highlights several of the mechanical and hydraulic upgrades that are performed during a turbine controls upgrade, including electronic overspeed protection (EOSP) systems. Applications include traditional steam turbines (utility, extraction, auxiliary drive) as well as alternative turbine layouts (hydro, combustion, combined cycle).
They explained that mechanical upgrades are performed in conjunction with turbine control upgrades to increase reliability and safety and optimize Ovation system compatibility. Existing mechanical equipment and instrumentation may be obsolete, unreliable, present single points of failure, and have limited online testability.
The Emerson turbine mechanical projects team provides full-scope mechanical retrofit and new installation services to interface the Ovation DCS and existing controls with plant equipment. These gas turbine controls can be applied to various turbine manufacturers’ units, and more than 1500 steam and gas turbine control systems have been installed.
Benefits of interfacing with Ovation distributed control systems (DCSs) include:
- Improved efficiencies and reduced maintenance – maximize high-speed I/O capabilities
- Data collection and trending
- Safety – overspeed and vibration
- Simplified operation – less parts and better design
Types of turbines to retrofit include utility and auxiliary steam, hydroelectric, combustion, as well as other industrial processes such as water and wastewater solutions.
Examples of mechanical upgrade projects include speed sensing, steam valve position feedback, and turbine trip system upgrades. They highlighted an example of a turbine trip system upgrade that included an Emerson Testable Dump Manifold (TDM). It has triple redundant fault tolerance, de-energize-to-trip fail-safe operation, testable online with diagnostics, and 2-out-of-3 hydraulic voting logic. These TDMs can be applied to steam and boiler feed turbines, combustion turbines, electrohydraulic control (EHC), and low-pressure applications.
Some EHC and hydraulic power unit customized solutions include standard configurations or ones designed to customer specifications for nominal reservoir capabilities from 50 to 1,000 gallons. Design considerations include tank capacity and pump sizing, particulate filtration, cooling and heating, instrumentation, motor starters, and local control and indication.
Keys to successful turbine control system and mechanical upgrade projects include the involvement of broad constituencies, including corporate engineering, plant maintenance, asset owners, operations and engineering personnel, and third-party contractors. Other essential factors include identifying and developing additional drivers and specifications, establishing realistic timelines, understanding expectations and return on investment considerations, having a comprehensive installation and commissioning plan, and proper coordination with other outage work and projects.
Visit the Project Services section on Emerson.com for more information on services to help improve turbine reliability and performance.
