The GE system being demonstrated for the U.S. Navy uses an On-Site Monitor (OSM) to gather engine operating data and to provide a communication interface with the Remote Monitoring Center at GE Marine Engines' Evendale, Ohio headquarters. Up to 1,000 parameters may be monitored on the gas turbine, including engine operating temperatures, pressures, speeds, vibration, and controls and status data such as alarms, trips and equipment on-off conditions. By applying statistical tools. GE can identify changes in engine performance that may indicate an incipient gas turbine or site problem.
6. Tailored Power Systems
The key to successful design of propulsion and power prime mover for commercial or naval vessels is an optimum system solution that balances the following:
Efficiency - matches power available to the load
Manning - operates with minimum personnel
Signature - reduces emissions and noise
Total life cycle cost - minimum for the user
Meeting the above objectives usually involves selection of an appropriate combination of prime movers. For many vessels this combinations has included diesels with gas turbines; environmental considerations are now driving these selections to combinations of small and large gas turbines.
Minimum life cycle cost is achieved through selection of prime mover combinations that fit the power requirement for best fuel efficiency, minimize maintenance, and reliably meet the mission requirements.
6.1 Commercial In Service Support
A key element of meeting ship power system requirements requires new approaches to support of engines in service. Aeroderivative gas turbines can take advantage of support arrangements that have been developed for aircraft engines. These arrangements involve total life support contracts including in place maintenance and depot refurbishment. The contracts typically have incentive provisions for engine availability, and are funded on a level cost per operating hour.
The advantages of such arrangements is that it reduces training requirements and maintenance investments for the customer, and removes the risk associated with a large, unplanned maintenance event. Such arrangements are now in place for commercial marine gas turbine customers (both fast ferry and cruise ship), and are being discussed for naval marine customers as well.
Conclusions
Application of gas turbines in marine vessels have advanced significantly from naval vessel in the 1970's, to a broad range of commercial and new naval configurations. The advances have come as a result of technical capability improvements in the gas turbines, but also because of the ingenious use of system combinations, which optimize performance. Emergent environmental requirements on ships have further stimulated the use of gas turbines.
Implementation of new concepts in maintenance support has further advanced the use of gas turbines in commercial and naval vessels. Total support contracts, including the use of remote diagnostics, allow operators to enjoy the benefits of advanced technology without the need for investment in support infrastructure.
Marine gas turbine application will certainly be extended to additional ship types, as the benefits are demonstrated in current installations. The characteristics that have made gas turbines attractive for naval applications, low weight and volume, high reliability, low maintenance, and low emissions, are being realized in more commercial classes. Effective system engineering will continue to yield efficient power systems that meet customer requirements of performance and low life cycle cost.
