EVENDALE, OH - GE Marine Engines' uprated LM6000 aeroderivative gas turbine is an ideal choice for various marine propulsion applications. Recent tests demonstrated the capability of the LM6000's Dry Low Emissions (DLE) combustion system to meet all current and projected naval and commercial marine environmental restrictions when operated on liquid fuel.
The LM6000, the world's most efficient simple-cycle gas turbine, features a unique configuration which allows the output power to be provided from either the hot or cold end of the turbine. The uprated LM6000 models have been designated PC (standard combustor) and PD (DLE combustion system). Both offer over 40 megawatts or more than 50,000 shaft horsepower (shp) with 42% ISO thermal efficiency. There are several commercial and military marine propulsion applications for the LM6000 currently being evaluated. In one instance, a single LM6000 could be used on a large monohull or catamaran fast ferry as the boost engine for high speed operation in combination with small diesels for maneuvering. A propulsion scheme that includes several LM6000 gas turbines is suitable for a variety of large cargo ship programs which require over 200 megawatts of power.
For military applications, multiple LM6000s are being considered for large combatant vessels such as aircraft carriers to provide up to 280,000 shp, or in surface combatants such as the DD21, to provide over 50,000 shp per shaft.
The LM6000 is suitable for differing engine propulsion schemes, including combined gas and gas turbine (COGAG) and combined diesel and gas turbine (CODAG). The gas turbine can be combined with diesel engines for low power operations or as the prime mover in electric drive propulsion configurations.
A major benefit of the LM6000 is the unit's compact size and fuel cost savings. An LM6000 commercial marine package measures 36 feet in length by 12 feet wide by 13 feet high, and weighs approximately 21 metric tons. Typical of all GE's aeroderivative gas turbines, the LM6000 produces less noise and vibration than comparable size diesels.
LM6000 Benefits For Marine Propulsion
- Over 40 megawatts or 50,000 shp installed power
- High 42% thermal efficiency for reduced fuel costs
- Less noise and vibration
- Low volume for weight savings
- Low initial cost and installation savings
- Efficient, proven DLE combustion system to meet strict global environmental legislation
Because of the unit's 42% overall thermal efficiency and low weight, owners and operators of marine vessels will experience significant fuels savings. Initial engine cost as well as savings during installation make the LM6000 an attractive marine propulsion alternative.
The first industrial LM6000 began commercial operation in December 1992, and the first of the enhanced power LM6000 gas turbines began commercial service in late 1997. Currently there are 115 LM6000s in operation, with over 1.2 million total fired hours.
Based on the operational tracking data provided by an independent source, the fleet of industrial LM6000 gas turbines has a 12-month rolling average of 99.5% reliability and 97.7% availability. In addition, environmental emission regulations are becoming increasingly stringent throughout the world. Owners and operators of marine vessels can now turn to GE's reliable and proven DLE combustion technology.
The next step in the development of DLE combustion for GE aeroderivative gas turbines is a dual-fuel system for the LM6000. In addition to the requirements already stated for the gas fueled system, it is planned that this system will have the following product requirements: Capable of operation on natural gas or distillate fuel without the use of water or steam injection to obtain low exhaust emissions; and capable of fuel switching without shutdown ("on the fly" operation).
The dual-fuel system is designed to produce initially guaranteed maximum concentrations of NOx of 65 ppmv and CO of 25 ppmv (@15% O2) on distillate fuel. On natural gas, the system will be designed to produce the same concentrations as the gas-only system. Testing of the dual-fuel DLE system was completed in the first quarter of 1998. The first dual-fuel DLE system will begin industrial commercial service in 1998.