Emerson converts turbines to dual-fuel operation at power plant in Colombia

  • August 19, 2009
  • Emerson Automation Solutions
  • Case Study
August 19, 2009 — Emerson Process Management completed a dual fuel-conversion initiative that enables the Termocandelaria power plant to operate using either natural gas or oil. The project, implemented by Emerson and Mitsubishi Power Systems Americas (MPSA), went into commercial operation in just 11 months, an aggressive timetable that was required in order for Termocandelaria to fulfill its regulatory obligations. The project marks the latest collaboration between Emerson and MPSA, which in 2008 formed an alliance for turbine retrofit projects. Termocandelaria, owned by Termocandelaria Power Ltd., is a two-unit, 320-MW power plant located in Cartagena, along Colombia’s Caribbean Coast. Converting the plant’s two Westinghouse 501F turbines from gas fuel only to dual-fuel operation offered Termocandelaria a low-risk, cost-effective strategy for improving unit startup reliability. By being able to start reliably and generate the requested power on demand, Termocandelaria not only maximizes its generating revenue but also avoids financial penalties that would be incurred if it were not able to fulfill its regulatory obligations with the Colombian Energy System.The Colombian electricity market is served primarily by hydro-electric plants located in the center of the country. When there is drought, transmission issues or high demand, these plants are not always able to generate sufficient power to meet the region’s needs. In these instances, the Colombian government typically calls on power plants utilizing other fuel sources, such as Termocandelaria, to provide additional megawatts. “Startup reliability has been greatly enhanced with the dual-fuel capability now in place, Termocandelaria is able to produce megawatts on demand,” said Miguel Angel Perez Ghisays, Plant Manager, Termocandelaria. “The significance of this cannot be underestimated, as the plant’s ability to be a reliable source of back-up power plays an important role in maintaining grid stability.”For this project, Emerson co-developed with MPSA a new control strategy for the dual fuel conversion, which included logic for water injection, fuel gas and fuel oil systems. In addition to the new logic required to accommodate a second fuel source, Emerson also migrated the existing gas turbine controls from the previous-generation WDPF distributed control system to its Ovation expert control system. As part of the migration, Emerson, a leader in power plant automation and turbine control solutions, converted the existing logic to industry standard SAMA logic. This will enable Termocandelaria to more easily modify control schemes in the future as changing circumstances dictate. From the beginning, Emerson designed the Ovation system to allow a straightforward migration path for users of its WDPF systems. This proven, economical alternative to complete system replacement offers WDPF customers the latest technology while allowing them to retain much of their existing control system investment, including control logic, graphics, I/O cards, field cabling and terminations. MPSA was responsible for the dual fuel conversion, including new combustion system components, gas and oil fuel supply systems featuring Emerson control valves and instrumentation, as well as civil and electrical design of the expanded balance of plant equipment for water and oil treatment and storage equipment. MPSA also provided installation and commissioning support for the project to achieve a certificate of completion by demonstrating power supply capabilities on oil fuel. Water-injected diffusion flame combustors (fuel nozzles, combustor baskets & transition pieces) were supplied to maximize the unit’s output and simplify the fuel conversion process. The retrofit also included MPSA’s new dual-fuel system, which utilizes a duplex liquid fuel nozzle to eliminate the need for a flow divider and improve start-up and low load particulate emissions and opacity. Purge air systems and Mitsubishi’s high energy ignition system were also applied to assure high starting reliability. “Emerson and MPSA worked well together to deliver a successful project for Termocandelaria within the required compressed timeframe,” said Bob Yeager, president of the Power & Water Solutions division of Emerson. “By leveraging the respective strengths of our two organizations, we were able to provide Termocandelaria with a comprehensive solution that met their objective of improving plant reliability and maximizing revenue.”Emerson's Ovation expert control system, which was designed specifically to meet the unique challenges of the power generation industry, offers unique features that other control systems don't have. These include fully coordinated boiler-turbine control, automated startup and shutdown sequencing, specialty turbine interface cards, built-in security features, and embedded advanced control applications that can dramatically improve plant reliability and efficiency. With Ovation technology, power generators no longer need to rely on their existing turbine supplier to support a proprietary control system. Ovation provides a clear window into the turbine control logic, eliminating the need for a third party to "unlock the black box." MPSA is one of the largest OEM service providers for gas turbine outages in North America with a proactive turbine service program focused on enhanced performance, turbine life extension, protection against avoidable damage and prevention of unplanned outages. MPSA brings a wealth of service support experience to its alliance with Emerson, including form-fit equivalent product modifications, long-term service agreements, gas and steam turbine outage services, and new and extended-life parts, as well as U.S.-based manufacturing, shop repair and engineering support. About Emerson Process ManagementEmerson Process Management, an Emerson business, is a leader in helping businesses automate their production, processing and distribution in the power, water and wastewater treatment, metals and mining, chemical, oil and gas, refining, pulp and paper, food and beverage, pharmaceutical, and other industries.Emerson's Power & Water Solutions division is a global supplier of advanced distributed process control and information systems. The Pittsburgh-based company is a recognized leader in developing plant-wide process control solutions for the power generation, water treatment and wastewater treatment industries. Power & Water Solutions plays a key role in the Emerson mission of combining superior products and technology with industry-specific engineering, consulting, project management and maintenance services. Emerson brands include: PlantWeb; Ovation; Scenario, SmartProcess; Fisher; Micro Motion; Rosemount; Daniel, DeltaV, and AMS Suite. Learn More

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