Metso DNA

Gas turbine automation

Bandirma, EnerjiSA Picture: © AE&E Power Plant Systems GmbH

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Not every turbine enjoys a diet of dry nat-ural gas high in methane over its life time. With the need to diversify the fuel sources and shave some cost from the gas bill many users are considering fuel alternatives that contain the heavier hydrocarbons, more car-bon dioxide, and more moisture. These gases in the form of LNG, LPG, refinery gas, and other process gases may be readily available on site and nearly free. These are the fuels that require more sophisticated control and monitoring of your turbine that Metso can deliver. If your combustion turbine’s diet consist of liquid fuels containing contami-nants such as vanadium and sulfur they can bond to the turbine blades leading to even-tual failure. By analyzing the vibration signa-tures throughout the turbine Metso can help you avoid a catastrophic turbine failure.

The Metso turbine control system can manage the on-line wash cycles and the crank wash and rinse cycle to get turbine power output back to nearly new specifica-tions and eliminate the mismatch between compressor isentropic efficiency and the gas turbine section of the machine.

game quickly with new tools. Control fea-tures include fuel management, emission control and turbine monitoring that alerts you to degradation resulting from hot sec-tion erosion, temperature imbalances caused by fuel energy densities that might be out-side the Wobbe Index of your machine’s design. You might be sourcing gas with heavy pentane or hexane content that is actually causing liquid carryover and conse-quent non-symmetric heating of the hot sections, particularly near the turbine bot-tom. Those heavy hydrocarbons can affect the dew point leading to flame flashbacks and blowouts as the flame velocity varies wildly. Metso’s Gas Turbine control package can identify those profit robbing problems while you can still do something about it.

ExperienceMetso has delivered turbine controls to plants around the world for controlling sim-ple cycle, combined cycle, and combined heat and power assets. Those Metso systems included speed, fuel and air controls; emis-sion controls; startup, shutdown, and cool down sequencing; temperature symmetry monitoring, vibration monitoring, overspeed protection; and engineering tools for dynamic analysis and system maintenance. Several have included control of on-line washing and periodic crank washing.

Comprehensive solution for

gas turbine automation

Benefits of Metso’s gas turbine automation• Open platform,

no black boxes• Control and protection

in one system• High availability• Easy and cost-effective

maintenance

Metso answers the needMetso offers the convenience and simplicity of a stand-alone gas turbine control com-bined with the thoroughness of a fully inte-grated system that delivers protection, con-dition monitoring, and aerothermal analysis, along with precise control of your turbine. By integrating gas turbine control, protec-tion, and scalable information management into an easily deployed combustion turbine retrofit package, Metso gets you back in the

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Metso DNA gas turbine automation The turbine automation gives you control of all aspects of turbine functionality:

All turbine controls easily accessed: •Speedcontrol• Load control• Emission control• Exhaust temperature control • Inlet temperature control• Combustion control• Fuel control as well as

dual fuel control• Automatic start-up, shutdown

and cooldown• Remote control

Integrated system performance:• Redundancy at all levels• Overspeed protection• High exhaust temperature

monitoring• Machine protection• Machine condition monitoring• Performance monitoring• Simulator for testing and training• Remote combustion and vibration

monitoring and support

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Automation system I/OThe Metso DNA servo control I/O unit deliv-ers high-speed (5 ms) control. The unit has a discrete, very fast (2 ms) fail-safe emergency shutdown function. This control unit is used together with a valve position measurement unit that contains an LVDT (Linear Valve Differential Transmitter) sensor input. A fast 0/4-20 mA input unit is also available.

Actuator controlsServo control action is done by a redun-dant process controller together with a ser-vo-control analogue output unit and LVDT or mA input unit. Valve position feedback is done with either LVDT or 0/4-20 mA input units. The LVDT unit is of the type where only the rod sensor is in the field while all the electronics are kept within the automa-tion system. The servo valve and other con-trols can be done with redundant I/O units to ensure high availability and easy on-line hot-swap maintenance.

• Operation• Maintenance• Reporting

• Governor control • Overspeed protection • Machine protection • Condition monitoring

Protect your assetsTurbine protection is an integral part of Metso DNA gas turbine automation.Monitoring and protection is needed to pre-vent severe mechanical damage, resulting in production downtime, as well as securing operational safety. Monitoring functions also provide predictive condition information that can be used to maximize production availability and maintenance efficiency.

Overspeed protectionThe Metso DNA Overspeed Protection unit is designed to be easy to use and easy to

Metso DNA for

integrated control and protection

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Machine protectionMachine protection is an important safety feature in all gas turbines. Gas turbines are subjected to continuous mechanical and thermal stress that may result in breakdowns over time. Metso DNA Machine Protection monitors a number of critical mechanical parameters, including:• Radial shaft vibration• Bearing housing vibration• Axial shaft position• Combustion monitoring

maintain – it fits in different configurations depending on the need for redundancy, or whether the 2oo3 (two out of three) voting is done in the unit or in the hydraulic trip-block. The unit can read various standard speed sensors and the design meets the industry standards for gas turbine overspeed protection. The unit is designed to meet SIL3 (Safety Integrity Level 3) functional safety requirements as defined in standard IEC-61508 ed. 2.0 and to meet the requirements for overspeed protection as defined in the API-670 standard.

Dedicated I/O units are provided for measur-ing static and dynamic positions and abso-lute vibrations with eddy current probes and accelerometers. Monitoring parameters are calculated and monitoring executed accord-ing to the API-670 standard. Calculated parameters can also be used for diagnostic purposes.

Connection to other systemsMetso DNA gas turbine automation can be connected to other plant systems by stan-dard communication protocols, such as Modbus TCP, PROFIBUS DP and OPC.

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Plant management applicationsMetso DNA Gas Turbine Performance Monitoring and Metso DNA Gas Turbine Wash Manager applications provide the power plant management and operating personnel with valuable information about the performance, condition, fouling and operating efficiency of the gas turbine. The purpose of the applications is to calculate, monitor and report the main performance-related parameters in reference conditions.

The results of the calculations are present-ed on displays and web-based reports, which help visualize the performance of the gas turbine at a glance.

The calculations are based on the applica-ble standards and are suitable for all com-monly used manufacturers’ gas turbines. All this information is provided both in real time and over the whole operating history.

Tools for predictive maintenanceMachine protection monitors the most criti-cal gas turbine parameters and provides safety interlocks to avoid catastrophic machine failures. Mechanical condition mon-itoring can also be extended to cover a wider range of diagnostic features for predic-tive maintenance. Predictive condition moni-toring provides diagnostic information for early detection of developing mechanical faults. This allows you to avoid unexpected shutdowns and plan maintenance actions according to need.

Metso DNA Machine Monitoring includes advanced diagnostic tools for gas turbine generators, such as shaft orbit monitoring with amplitude and phase characteristics as well as spectral vibration analysis. Predictive condition monitoring can be easily expanded to cover the balance of the plant machinery to secure maximum production availability.

Responding to maintenance needsWith the plant management applications, a power plant’s maintenance and operating personnel can detect hidden problems in the gas turbine operation. These problems can then be analyzed with Metso DNA’s advanced tools. This contributes towards proactive responding to failures before they cause unpredicted shutdowns. The data stored in the Metso DNA Historian plays an important role in monitoring the wear of components over time. Clear and under-standable visualization makes the scheduling of maintenance considerably easier.

In addition to the on-line monitoring of vibration and combustion, Metso’s experts can provide remote support. With the stored history data it is also possible to replay the disturbance situations and gain knowledge through the organization. The application is linked seamlessly to the automation system, which leverages the benefits of the integrat-ed system.

Tools for effective

maintenance and management

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Calculated indicators:

Metso DNA Gas Turbine Monitoring• Compressor inlet temperature • Exhaust gas temperature

spread (min, ave, max)• Specific fuel consumption • Heat rate • Thermal efficiency • Electrical efficiency

Metso DNA Gas Turbine Wash Manager• Electric power generated• Heat rate • Heat consumption • Electrical efficiency • Exhaust temperature • Lost power production due to

compressor/filter fouling • Economical loss caused by

compressor/filter fouling • Wash expenses

Turbine simulator• Runs on Metso DNA platform • For training and FAT purposes• Operators prepared for

real life situations• Easy to update and

modify

Tools for effective

maintenance and management

Metso Automation Inc., www.metso.com/automation E880

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