Aero-derivative gas turbines have been successfully serving the power generation, mechanical drive, and marine markets for 40 years. These products are well suited for distributed generation, with sizes in the range from 3 MW to 50+ MW. The Rolls-Royce group of companies provide vertical integration for aero-derivative based energy systems, having marketing, sales, manufacturing, packaging, distribution, and customer service capabilities.
The 3– 6 MW, 501-K family serves power generation and cogeneration applications. The new 6–8 MW 601 is used for cogeneration and mechanical drive. The 15 MW Avon is widely applied to mechanical drives, offering exceptional reliability and low life cycle cost. The RB211 provides over 30 MW at high efficiency, and is used in mechanical drive and electrical generation.
The 42% efficient, 50 MW, Trent is primarily intended for electrical generation. This engine retains a higher than usual degree of commonality with aero production modules, thus retaining the cost advantage of high volume production and benefits from continuous improvements in aero engines.
Plans: Cost reduction of mature existing products will be achieved by “industrialization”, e.g. by alloy changes and shape simplification, of parts no longer in aero production. Better integrated packaging and “more electric aircraft” features are rapidly becoming a necessity in the competitive marketplace. The trend is toward minimizing and possibly eliminating mechanical drives and other components in a gas turbine to improve product quality, efficiency, reduce product cost, while enhancing product quality and the environment. In this regard, the approach being taken near term is to substitute normal oil bearings with Active Magnetic Bearings. Such an action would help eliminate high cost skid lubrication system components and some environmental hazards as well as reducing maintenance.
Several programs will make contributions to environmental improvements through reduced emissions and the use of “renewable” fuels.
A prototype 501-K has been supplied to operate on gasified coal, a reduced emissions path to generating electricity from coal. A dual fuel DLE combustion system for very high pressure ratio and turbine temperature is in development for the Trent, having downward compatibility with other company products.
The Next Generation Gas Turbine (NGGT) project, sponsored by the US Department of Energy, will use an existing engine core. Advanced modules, including a long life “spiral” recuperator and cycle enhancements combine to yield 50% cycle efficiency at a reduced cost per kW. The goal is to produce a 50 MW class plant with “combined cycle efficiency at simple cycle cost.” The NGGT is suited to using alternate fuel for part of the energy input.
Following evaluation of fuel cell/gas turbine hybrids, a specially suited gas turbine development is being initiated with sponsorship by the U.S. Department of Energy. The company is also conducting a solid oxide fuel cell program.
An auxiliary power unit(APU) was developed and is now in production for the M1 tank. A “microturbine” derivative of this product is being considered for distributed generation.
Biomass Gasification for Gas Turbine Based Power Generation
