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 provide for lower maintenance costs, increased reliability and better system response. The 16 LM2500 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. 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. 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.Benefits of the DFC technology are numerous and 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.
Source: geaviation, October 11, 2011