Combined Diesel and LM2500 Gas Turbine Propulsion Enhances Corvette/Frigate Missions

1984 ◽  
Vol 106 (3) ◽  
pp. 645-653
Author(s):  
P. A. Dupuy

The LM2500 Gas Turbine is used for propulsion of naval ships from 220 tons to 14,000 tons displacement. Those ships from 220 to 4000 tons have used combined diesel or gas turbine (CODOG) systems in all but one ship class. Destroyers and larger ships, 7000 tons and up, have all used solely LM2500 turbines as Combined Gas Turbine and Gas Turbine (COGAG). Recently, the diesel engine industry has announced the advent of technological developments whereby diesel engine specific power can be significantly increased. Thus it is being suggested that with this new technology, all diesel propulsion (CODAD) can replace various propulsion systems currently using combined diesels with gas turbines. This paper explores the desired mission objectives for corvette/frigate class ships and develops an analytical comparison of all diesel and combined propulsion abilities to satisfy the ship’s missions. The comparison assesses the system’s relative impact upon propulsion system acquisition and life operating cost, system operational flexibility, ship’s detectability, and overall ability of the ship to perform the broadest range of mission requirements.

Author(s):  
Erwin Zauner ◽  
Yau-Pin Chyou ◽  
Frederic Walraven ◽  
Rolf Althaus

Power generation in gas turbines is facing three main challenges today: • Low pollution prescribed by legal requirements. • High efficiency to obtain low operating cost and low CO2 emissions. • High specific power output to obtain low product and installation cost. Unfortunately, some of these requirements are contradictory: high efficiency and specific power force the development towards higher temperatures and pressures which increase NOx emissions and intensify the cooling and material strength problems. A breakthrough can be achieved by applying an energy exchanger as a topping stage. Inherent advantages are the self-cooled cell-rotor which can be exposed to much higher gas temperature than a steady-flow turbine and a very short residence time at peak temperature which keeps NOx emissions under control. The basic idea has been proposed long time ago. Fundamental research has now led to a new energy exchanger concept. Key issues include symmetric pressure-wave processes, partial suppression of flow separation and fluid mixing, as well as quick afterburning in premixed mode. The concept has been proven in a laboratory-scale engine with very promising results. The application of an energy exchanger as a topping stage onto existing gas turbines would increase the efficiency by 17% (relative) and the power by 25%. Since the temperature level in the turbine remains unchanged, the performance improvement can also be fully utilized in combined cycle applications. This process indicates great potentials for developing advanced gas turbine systems as well as for retrofitting existing ones.


Author(s):  
A. K. Anand ◽  
C. S. Cook ◽  
J. C. Corman ◽  
A. R. Smith

The application of gas turbine technology to IGCC systems requires careful consideration of the degree and type of integration used during the system design phase. Although gas turbines provide the primary output and efficiency gains for IGCC systems, as compared with conventional coal fired power generation systems, they are commercially available only in specific size ranges. Therefore, it is up to the IGCC system designer to optimize the IGCC power plant within the required output, efficiency and site conditions by selecting the system configuration carefully, particularly for air separation unit (ASU) integration incorporated with oxygen blown gasification systems. An IGCC system, based on a generic, entrained flow, oxygen blown gasification system and a GE STAG 109FA combined cycle has been evaluated with varying degrees of ASU integration, two fuel equivalent heating values and two gas turbine firing temperatures to provide net plant output and efficiency results. The data presented illustrate the system flexibility afforded by variation of ASU integration and the potential performance gains available through the continued use of gas turbine advances. Emphasis is place on system design choices which favor either low initial investment cost or low operating cost for a given IGCC system output.


1996 ◽  
Vol 118 (4) ◽  
pp. 732-736 ◽  
Author(s):  
A. K. Anand ◽  
C. S. Cook ◽  
J. C. Corman ◽  
A. R. Smith

The application of gas turbine technology to IGCC systems requires careful consideration of the degree and type of integration used during the system design phase. Although gas turbines provide the primary output and efficiency gains for IGCC systems, as compared with conventional coal-fired power generation systems, they are commercially available only in specific size ranges. Therefore, it is up to the IGCC system designer to optimize the IGCC power plant within the required output, efficiency, and site conditions by selecting the system configuration carefully, particularly for air separation unit (ASU) integration incorporated with oxygen blown gasification systems. An IGCC system, based on a generic, entrained flow, oxygen blown gasification system and a GE STAG 109FA combined cycle has been evaluated with varying degrees of ASU integration, two fuel equivalent heating values and two gas turbine firing temperatures to provide net plant output and efficiency results. The data presented illustrate the system flexibility afforded by variation of ASU integration and the potential performance gains available through the continued use of gas turbine advances. Emphasis is placed on system design choices that favor either low initial investment cost or low operating cost for a given IGCC system output.


Author(s):  
Glenn McAndrews

Electric starter development programs have been the subject of ASME technical papers for over two decades. Offering significant advantages over hydraulic or pneumatic starters, electric starters are now poised to be the preferred choice amongst gas turbine customers. That they are not now the dominant starter in the field after decades of investment and experimentation is attributable to many factors. As with any new technology, progress is often unsteady, depending on budgets, market conditions, customer buy-in, etc. Additionally, technological advances in the parent technologies, in this case electric motors, can abruptly and rapidly change, further disturbing the best laid introduction plans. It is therefore not too surprising that only recently, is the industry beginning to see the deployment of electric starters on production gas turbines. The earliest adoption occurred on smaller gas turbine units, generally less than 10 MW in power. More recently, gas turbines greater than 10 MWs are being sold with electric starters. The authors expect that regardless of their size or fuel supply, most all future gas turbine users will opt for electric starters. This may even include the “larger” frame machines with power greater than 100 MW. Starting with some past history, this paper will not only summarize past development efforts, it will attempt to examine the current deployment of electric starters throughout the marine and industrial gas turbine landscapes. The large-scale acceptance of electric start systems for both new production and retrofit will depend on the favorable cost/benefit assessment when weighing both first cost and life cycle cost. The current and intense activity in electric vehicle applications is giving rise to even more power dense motors. The paper will look at some of these exciting applications, the installed products, and the technologies behind the products. To what extent these new products may serve the needs of the gas turbine community will be the central question this paper attempts to answer.


Author(s):  
Qun Zheng ◽  
Minghong Li ◽  
Yufeng Sun

Thermodynamic performance of wet compression and regenerative (WCR) gas turbine are investigated in this paper. The regenerative process can be achieved by a gas/air (and steam) heat exchanger, a regenerator, or by a heat recovery steam generator and then the steam injected into the gas turbine. Several schemes of the above wet compression and regenerative cycles are computed and analyzed. The calculated results indicate that not only a significant specific power can be obtained, but also is the WCR gas turbine an economic competitive option of efficient gas turbines.


Author(s):  
M. Badger ◽  
A. Julien ◽  
A. D. LeBlanc ◽  
S. H. Moustapha ◽  
A. Prabhu ◽  
...  

The PT6 engine entered service in the mid-1960’s. Since then, application of new technology, has enabled low cost development of engines approaching 1500 KW, the introduction of electronic controls, improved power-to-weight ratio, higher cycle temperature and reduced specific fuel consumption. At the same time, PT6 field experience in business, commuter, helicopter and trainer applications has resulted in engines with low Direct Operating Cost and a reputation for rugged design and a high standard of engine reliability. This paper will highlight some interesting examples of this technical evolution, including the development of electronic controls and the application of the latest 3D aerodynamic and stress analysis to both compressor and turbine components.


1983 ◽  
Vol 105 (4) ◽  
pp. 821-825 ◽  
Author(s):  
J. Wolf ◽  
S. Moskowitz

Studies of combined cycle electic power plants have shown that increasing the firing temperature and pressure ratio of the gas turbine can substantially improve the specific power output of the gas turbine as well as the combined cycle plant efficiency. Clearly this is a direction in which we can proceed to conserve the world’s dwindling petroleum fuel supplies. Furthermore, tomorrow’s gas turbines must do more than operate at higher temperature; they will likely face an aggressive hot gas stream created by the combustion of heavier oils or coal-derived liquid or gaseous fuels. Extensive tests have been performed on two rotating turbine rigs, each with a transpiration air cooled turbine operating in the 2600 to 3000°F (1427 to 1649°C) temperature range at increasing levels of gas stream particulates and alkali metal salts to simulate operation on coal-derived fuel. Transpiration air cooling was shown to be effective in maintaining acceptable metal temperatures, and there was no evidence of corrosion, erosion, or deposition. The rate of transpiration skin cooling flow capacity exhibited a minor loss in the initial exposure to the particulate laden gas stream of less than 100 hours, but the flow reduction was commensurate with that produced by normal oxidation of the skin material at the operating temperatures of 1350°F (732°C). The data on skin permeability loss from both cascade and engine tests compared favorably with laboratory furnace oxidation skin specimens. To date, over 10,000 hr of furnace exposure has been conducted. Extrapolation of the data to 50,000 hr indicates the flow capacity loss would produce an acceptable 50°F (10°C) increase in skin operating temperature.


1975 ◽  
Author(s):  
Rolf Keller

After numerous tests over the last 40 years, the aircraft gas turbine of two-shaft design has emerged as the most promising power unit for high-powered, fast and lightweight rail vehicles of the future. The performance characteristics, superior to those of the diesel engine, are complemented either by an electrical transmission system or a hydraulic transmission unit. The advantage of the gas turbine lies in its compactness and lightness in weight, allowing a doubling of power and savings in space. Viewed from a commercial standpoint, this means a covering of fuel costs. In respect of noise development and exhaust gas emission, the gas turbine is also more favorable than the diesel engine. The most successful series-built vehicles powered by gas turbines are the turbotrains of the SNCF which have also been imported into the USA where they are to be built under license.


1993 ◽  
Author(s):  
Herman B. Urbach ◽  
Donald T. Knauss ◽  
David B. Patchett ◽  
John G. Purnell ◽  
Rolf K. Muench ◽  
...  

The steam-augmented gas turbine (SAGT) has attracted attention because of its increased fuel efficiency. It yields significant, cost-effective increments of output power, particularly when steam/water injection is increased to levels approaching 50% of air flow. Such high levels of steam/water consumption permit burner operation near stoichiometric combustion ratios with specific powers exceeding 580 hp-sec/lb anticipated. This paper examines steam-augmented gas turbines for their applicability in Navy DDG-class ship environments. SAGT engine concepts exhibit efficiencies approaching the Navy’s intercooled regenerative (ICR) engine, and an impressive compactness that arises from the high specific power of steam. Polished water consumption may be 425,000 gal/day for a 100,000-hp SAGT-engine ship plant. Nevertheless, SAGT engine systems impose little if any negative ship impact even after accounting for water purification systems. Moreover, because of their high specific power, SAGT systems are as affordable, on a first-acquisition-cost basis, as the current gas turbine systems in the fleet, and in the present supply pipeline.


2011 ◽  
Vol 18 (4) ◽  
pp. 43-48 ◽  
Author(s):  
Marek Dzida ◽  
Wojciech Olszewski

Comparing combined gas tubrine/steam turbine and marine low speed piston engine/steam turbine systems in naval applications The article compares combined systems in naval applications. The object of the analysis is the combined gas turbine/steam turbine system which is compared to the combined marine low-speed Diesel engine/steam turbine system. The comparison refers to the additional power and efficiency increase resulting from the use of the heat in the exhaust gas leaving the piston engine or the gas turbine. In the analysis a number of types of gas turbines with different exhaust gas temperatures and two large-power low-speed piston engines have been taken into account. The comparison bases on the assumption about comparable power ranges of the main engine.


Sign in / Sign up

Export Citation Format

Share Document