Gas Turbine Propulsion for LNG Transports

Author(s):  
Louis Ellington ◽  
Glenn McAndrews ◽  
Alexander Harsema-Mensonides ◽  
Ravi Tanwar

GE aero-derivative gas turbines were first introduced into marine operations during the late 1960’s and early 1970’s. GE is now leveraging its many years of proven marine experience and offshore dual-fuel experience to offer dual-fuel gas turbines for LNG Carrier (LNGC) propulsion and electric power. With building of new larger LNGC’s now beginning, the industry is seriously considering a change to gas turbine based systems in order to capitalize on their many advantages. CoGES (combined gas turbine — steam generator electric) plants for LNGC’s consist of dual-fueled gas-turbine-generator (GTG) set(s) and auxiliaries, heatrecovery steam generator (HSRG), a steam-turbine-generator set, feed-water, steam and condensate systems. Leveraging cruise-ship reliability programs, the GTG instrumentation and control systems are single-point fault tolerant. Gas turbine power plants offer many additional advantages, including but not limited to: Use of boil-off gas as a cost-effective and environmentally friendly fuel (slow speed diesel ships require complex on-board reliquifaction of boil-off gas). When installed on deck, CoGES plants provide high power-volume density that translates into increased cargo revenue and deferred capital cost. Gas turbines ease of maintenance and quick changeout. Developed to meet the International Code for the Construction and Equipment of Ships Carrying Liquefied Gases in Bulk (IGC) and classification society standards for marine applications, GE’s 2 X LM2500 CoGES plant is a very simple and reliable solution. Dry-run capable HRSG’s are used in lieu of exhaust damper and by-pass systems. Outage of any one prime mover leaves the plant with nominally 50% power remaining. Common spares are inherent. Established as having an equivalent level of safety as traditional LNGC propulsion systems via FMECA type studies, the 2 x dual-fueled LM2500 CoGES plant has been “Approved in Principle” by Class for use on LNG Carriers. Alternatively, GE’s 1 X dual-fueled LM6000 or 1 X LM2500+/G4 CoGES plant addresses capital & operating cost pressures via reduced equipment costs and improved fuel economy. Redundancy and simplicity are achieved via a dry-run capable HRSG and an STG, combined with auxiliary diesel generator sets. Both the LM2500 family and LM6000 CoGES plants offer viable alternatives to traditional steam turbine and slow-speed-diesel propulsion. Gas-fuel, liquid-fuel, and bi-fuel operation provide flexibility and redundancy to ship owners who must safely and reliably deliver cargo at the lowest possible cost per MMBTU throughout a fleet life cycle.

1979 ◽  
Author(s):  
L. F. Fougere ◽  
H. G. Stewart ◽  
J. Bell

Citizens Utilities Company’s Kauai Electric Division is the electric utility on the Island of Kauai, fourth largest and westernmost as well as northernmost of the Hawaiian Islands. As a result of growing load requirements, additional generating capacity was required that would afford a high level of reliability and operating flexibility and good fuel economy at reasonable capital investment. To meet these requirements, a combined cycle arrangement was completed in 1978 utilizing one existing gas turbine-generator and one new gas turbine-generator, both exhausting to a new heat recovery steam generator which supplies steam to an existing steam turbine-generator. Damper controlled ducting directs exhaust gas from either gas turbine, one at a time, through the heat recovery steam generator. The existing oil-fired steam boiler remains available to power the steam turbine-generator independently or in parallel with the heat recovery steam generator. The gas turbines can operate either in simple cycle as peaking units or in combined cycle, one at a time, as base load units. This arrangement provides excellent operating reliability and flexibility, and the most favorable economics of all generating arrangements for the service required.


Author(s):  
G. Negri di Montenegro ◽  
M. Gambini ◽  
A. Peretto

This study is concerned with the repowering of existing steam power plants (SPP) by gas turbine (GT) units. The energy integration between SPP and GT is analyzed taking into particular account the employment of simple and complex cycle gas turbines. With regard to this, three different gas turbine has been considered: simple Brayton cycle, regenerative cycle and reheat cycle. Each of these cycles has been considered for feed water repowering of three different existing steam power plants. Moreover, the energy integration between the above plants has been analyzed taking into account three different assumptions for the SPP off-design conditions. In particular it has been established to keep the nominal value for steam turbine power output or for steam flow-rate at the steam turbine inlet or, finally, for steam flow-rate in the condenser. The numerical analysis has been carried out by the employment of numerical models regarding SPP and GT, developed by the authors. These models have been here properly connected to evaluate the performance of the repowered plants. The results of the investigation have revealed the interest of considering the use of complex cycle gas turbines, especially reheat cycles, for the feed water repowering of steam power plants. It should be taken into account that these energy advantages are determined by a repowering solution, i.e. feed water repowering which, although it is attractive for its simplicity, do not generally allows, with Brayton cycle, a better exploitation of the energy system integration in comparison with other repowering solutions. Besides these energy considerations, an analysis on the effects induced by repowering in the working parameters of existing components is also explained.


2005 ◽  
Author(s):  
H. Andreasson ◽  
M. Källman ◽  
H. Liljenberg ◽  
H. Olofsson ◽  
P. Trägårdh ◽  
...  

The market demands for larger freight volumes are pushing the LNG industry towards larger vessels, new concepts and new technical solutions. Alternative machinery installations are being investigated including one steam turbine, one/two slow speed diesel(s), one/two dual fuel engine(s), one/two gas turbine(s) and one/two diesel electric installation(s). Twin skeg is one alternative propulsion solution for larger LNG ships. In this paper, operational analysis, manoeuvrability, risk assessment and performance of the LNG twin skeg concept will be discussed.


Author(s):  
H. A. Bazzini

Much of the steam-turbine based, power generating units all over the word are more than 30 years old now. Within a few years they will face the possibility of retirement from service and replacement. Nonetheless some of them are firm candidates for repowering, a technology able to improve plant efficiency, output and reliability at low costs. This paper summarizes a study performed to establish the feasibility to repower a 2 × 33 MW steam turbine power plant and the procedure followed until selection of the steam cycle more suitable to the project. The preferred solution is compared with direct replacement of the units by a new combined cycle. Various repowering options were reviewed to find “beat recovery” type repowering as the best solution. That well-known technology consists of replacing the steam generator by a gas turbine coupled to an HRSG, supplying steam to the existing steam turbine. Three “GT+HRSG+ST” arrangements were considered. Available gas turbine-generators — both industrial and aero-derivative type —, were surveyed for three power output ranges. Five “typical” gas turbine-generator classes were then selected. Steam flow raised at the HRSG, gross and net power generation, and heat exchanging surface area of the HRSG, were calculated for a broad range of usually applied, steam turbine throttle conditions. Both single pressure and double pressure steam cycles were considered, as well as supplemental fire and convenience of utilizing the existing feed water heaters. Balance of plant constraints were also reviewed. Estimates were developed for total investment, O&M costs, fuel expenses, and revenues. Results are shown through various graphics and tables. The route leading to the preferred solution is explained and a sensitivity analysis added to validate the selection. The preferred solution, consisting in a Class 130 gas turbine in arrangement 1–1–2, a dual-pressure HRSG and a steam cycle without feed-water heaters, win allow delivering 200 MW to the grid, with a heat rate of 7423 kJ/kW-hr. Investment was valued at $MM77.0, with an IRR of 15.3%. Those figures compare well with the option of installing a new GTCC unit: with a better heat rate but an investment valued at $MM97.5, its IRR will only be 12.4%.


Author(s):  
Morgan L. Hendry ◽  
B. Michael Zekas

The U.S. Navy has nearly forty years of experience using SSS (Synchro-Self-Shifting) Clutches in main reduction gears of gas-turbine-driven ships and propulsion systems with combinations of gas turbines and diesel engines or electric motors, and in steam-turbine propulsion plants for use with electric motor drives. Over 900 SSS Clutches have been installed in fourteen different classes of U.S. Navy ships, some in service for over thirty years. This paper presents a brief overview of the principle SSS Clutch design features and the operating experience in naval propulsion systems worldwide, including operation in various propulsion plants such as controllable reversible pitch (CRP) propellers, fixed-pitch propellers (FPP), etc. The paper will also focus on SSS Clutch designs for specific U.S. Navy applications and installations, U.S. Navy experience, and design changes and improvements that have been implemented since the initial U.S. Navy use of SSS Clutches. Detailed metric (statistical) data, used by the U.S. Navy to evaluate equipment performance and life cycle costs, such as mean time between failure (MTBF), mean time to repair (MTTR), mean logistics delay time (MLDT), and operational availability (Ao) will be used to support experience. In-service experience and failure modes will also be explained as well as findings from the evaluation of clutches that have been subjected to extreme operation/incidents such as overspeed, overtorque, high shock blast, and flood damage. The final part of the paper will discuss current/future applications on U.S. Navy vessels such as the LHD-8, LCS and others; and how the design/features of those SSS Clutch designs will satisfy the operational, reliability, and maintainability requirements established for each ship platform. The metrics and lessons learned will be shown to be equally applicable to clutches for critical auxiliary drive applications such as naval gas turbine generator starting and naval steam turbine generator turning gear systems and how these metrics and lessons learned are being applied for current and future U.S. Navy ship systems.


Author(s):  
A.A. Filimonova ◽  
◽  
N.D. Chichirova ◽  
A.A. Chichirov ◽  
A.A. Batalova ◽  
...  

The article provides an overview of modern high-performance combined-cycle plants and gas turbine plants with waste heat boilers. The forecast for the introduction of gas turbine equipment at TPPs in the world and in Russia is presented. The classification of gas turbines according to the degree of energy efficiency and operational characteristics is given. Waste heat boilers are characterized in terms of design and associated performance and efficiency. To achieve high operating parameters of gas turbine and boiler equipment, it is necessary to use, among other things, modern water treatment equipment. The article discusses modern effective technologies, the leading place among which is occupied by membrane, and especially baromembrane methods of preparing feed water-waste heat boilers. At the same time, the ion exchange technology remains one of the most demanded at TPPs in the Russian Federation.


Author(s):  
Bernhard Ćosić ◽  
Frank Reiss ◽  
Marc Blümer ◽  
Christian Frekers ◽  
Franklin Genin ◽  
...  

Abstract Industrial gas turbines like the MGT6000 are often operated as power supply or as mechanical drives. In these applications, liquid fuels like 'Diesel Fuel No.2' can be used either as main fuel or as backup fuel if natural gas is not reliably available. The MAN Gas Turbines (MGT) operate with the Advanced Can Combustion (ACC) system, which is capable of ultra-low NOx emissions for gaseous fuels. This system has been further developed to provide dry dual fuel capability. In the present paper, we describe the design and detailed experimental validation process of the liquid fuel injection, and its integration into the gas turbine package. A central lance with an integrated two-stage nozzle is employed as a liquid pilot stage, enabling ignition and start-up of the engine on liquid fuel only. The pilot stage is continuously operated, whereas the bulk of the liquid fuel is injected through the premixed combustor stage. The premixed stage comprises a set of four decentralized nozzles based on fluidic oscillator atomizers, wherein atomization of the liquid fuel is achieved through self-induced oscillations. We present results illustrating the spray, hydrodynamic, and emission performance of the injectors. Extensive testing of the burner at atmospheric and full load high-pressure conditions has been performed, before verification within full engine tests. We show the design of the fuel supply and distribution system. Finally, we discuss the integration of the dual fuel system into the standard gas turbine package of the MGT6000.


Author(s):  
J R Bolter

Sir Charles Parsons died some three years after the author was born. In this paper the author looks back at the pioneering work of Parsons in the field of power generation. It shows how he was able to increase output of the steam turbine generator from 7.5 kW in 1884 to 50000 kW in 1930 while increasing efficiency from 1.6 to 36 per cent, and relates these achievements to the current state of the art. Blading design, rotor construction and other aspects of turbine engineering are considered. The conclusion is that Parsons and his associates charted the course which manufacturers and utilities throughout the world have continued to follow, although increasingly sophisticated design and analytical methods have succeeded the intuitive approach of Parsons. His constant search for improved efficiency was and is highly relevant to today's concern for the environment. Finally, although it did not become a practical proposition in his lifetime, the paper reviews Parsons' vision of, and continuing interest in, the gas turbine, first mentioned in his 1884 patents.


2011 ◽  
Vol 133 (04) ◽  
pp. 52-52
Author(s):  
Rainer Kurz

This article discusses the importance of gas turbines, centrifugal compressors and pumps, and other turbomachines in processes that bring natural gas to the end users. To be useful, the natural gas coming from a large number of small wells has to be gathered. This process requires compression of the gas in several stages, before it is processed in a gas plant, where contaminants and heavier hydrocarbons are stripped from the gas. From the gas plant, the gas is recompressed and fed into a pipeline. In all these compression processes, centrifugal gas compressors driven by industrial gas turbines or electric motors play an important role. Turbomachines are used in a variety of applications for the production of oil and associated gas. For example, gas turbine generator sets often provide electrical power for offshore platforms or remote oil and gas fields. Offshore platforms have a large electrical demand, often requiring multiple large gas turbine generator sets. Similarly, centrifugal gas compressors, driven by gas turbines or by electric motors are the benchmark products to pump gas through pipelines, anywhere in the world.


Author(s):  
G. E. Parker

Controls for small lightweight gas turbines present some unique design problems. The requirements for small size, light weight, ability to rotate at high speeds to save reduction gearing, and low production cost conflict with the requirements for reasonably accurate control of very small fuel flows and the scheduling of a wide range of hydrocarbon fuels over a wide range of ambient temperatures. This paper discusses in some detail the design of such a control and the satisfactory results obtained.


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