GE Marine reports that the United States Navy has ordered an
additional 16 Digital Fuel Control (DFC) kits for LM2500 marine aeroderivative gas turbines. The DFC kits are designed to provide for lower maintenance costs,
increased reliability and better system response.
The 16 LM2500s to be retrofitted power the U.S. Navy’s CG-47
Ticonderoga-class cruisers and DDG-51 Arleigh Burke-class destroyers, as well
as the T-AOE-8 fast combat ship. The DFC kits incorporate the most
state-of-the-art controls available for GE LM gas turbines – a technology now
standard on new LM2500 and LM2500+ engines, GE says. Previous-generation
LM2500s use a hydro-mechanical control system.
The LM2500s already retrofitted on select DDG-51 and CG-47
class ships have accumulated nearly 200,000 DFC operating hours, GE says. The
kits are installed as part of a U.S. Navy’s ship system modernization program.
The first LM2500 equipped with the DFC technology was
installed by the U.S. Navy in 1994 aboard the Watson class large, medium-speed,
roll-on/roll-off ships. The DFC technology -- as part of the standard engine
equipment -- also has been delivered to international navies for LM2500 gas
turbines applications, as well as on a variety of commercial projects where GE
gas turbines are used to power cruise ships and fast ferries.
GE says benefits of the DFC technology include:
• Improved engine resistance to possible fuel contamination
through oil actuation of variable stator vanes (VSV) and the fuel metering
valve.
• Updated control of fuel and air scheduling within the gas
turbine provides more accurate fuel/air scheduling through electrical feedback
and closed-loop control. In addition, fuel characteristics and VSV positions
can be recalibrated through the control software inputs.
• Gas turbine control sensor redundancy on compressor discharge
pressure, compressor inlet temperature and pressure, gas generator speed, VSV
position, and fuel metering valve position.
• Improved operator signals, alarms, and troubleshooting are
provided by additional electrical sensors and actuator feedback. GE DFC kits
also offer improved capabilities for data capture and condition monitoring.
• Primary DFC retrofit kit components include a fuel
metering valve and two VSV actuators, both with redundant electronic
feedback. An upgraded engine controller
and shipboard wiring changes are also required to incorporate the DFC kit.