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Features
The Gas Turbine Fuel Control (GTFC)
system provides a unique approach to integrated and stand-alone fuel control for new and
retrofit applications and can be configured for the control of any gas turbine.
Dresser-Rand Control Systems designed the GTFC system using the GE Fanuc 90-70
Programmable Logic Controller (PLC). The GE Fanuc PLC uses the open architecture, VME bus
standard, which allows for the integration of third party, special purpose modules in the
PLC backplane.  Conventional PLC input/output (I/0) modules are used
for standard I/0 requirements of the GTFC. Specialized modules and external hardware are
used to supplement the PLC I/0 modules when necessary and handle non-standard I/0
requirements.
The PLC can also be programmed to control and monitor the
driver and the driven equipment, provide compressor surge and capacity control, generator
control and the control of auxiliary and related process equipment.
A fail safe hard-wired
relay based shutdown system, with inputs from the PLC, is used to assure a fast, safe
shutdown in the event of an engine or controller malfunction.
Benefits
- The GTFC is fully configurable to any gas
turbine/driven equipment combination utilizing either single or dual fuel.
- The GTFC is typically integrated into the
train control system. This integration results in increased train control system
availability and reliability and a reduced system cost because a dedicated fuel control
processor, rack and power supply are not required.
- The GTFC can be supplied in redundant
configurations.
- Dresser-Rand's DI-TRONICS IV train control
system operator interface provides a graphic representation of the control scheme being
used and also displays other control parameters.
- The GTFC is programmed using an IBM
compatible computer. The PLC Ladder Logic programming package is used to configure the
GTFC system and view all system parameters. The programming computer can also be used as
the primary operator interface in stand alone applications where complete train control is
not provided in the PLC.
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Legend
CPU Central Processing Unit
ESD Emergency Shutdown
GG Gas Generator
GTFC Gas Turbine Fuel Control
HS High Select
LS Low Select
NGG Gas Generator Speed
NPT Power Turbine Speed
PID Proportional - Integral - Derivative
PLC Programmable Logic Controller
PT Power Turbine
T2 Gas Generator Inlet Temperature
T5 Gas Generator Exhaust Gas Temperature
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Speed Control
Speed control is used to position the fuel control valve at the minimum
fuel flow requirement and still maintain the power turbine speed requested. The following control formats are provided.
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1. NGG Control
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5. T2 Limiting Schedule
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2. NGG Limiting Control
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6. Maximum Valve Schedule
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3. NPT Control
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7. Minimum Valve Schedule
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4. EGT Control
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Operator Interface Display
The PLC operator interface monitor
serves as the primary display mechanism. The operator interface monitor provides the
operator with a visual display using the format seen in Figure 2. The graphic will be
highlighted to show the speed control method being used. Other critical fuel control
parameters will be displayed in a text based format.
Programming and Communications
The PLC ladder logic software is
used to program the GTFC. A communications port can be supplied with the system for
communication with other control systems or data gathering systems.
| Hardware Specifications |
| Operating
Temperature |
0 to
60° C
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| Humidity |
5% to 95% (non condensing) |
| Applications |
| Gas
Turbine Driven - Compressors, Generators, Pumps |
| Fuel Types |
Gas and Liquid |
| Fuel Control
Valves |
Single and Dual Fuel |
| Redundant Systems |
Various |
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