THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS ,98-GT=41; „ 345E 47th St, New York, N.Y:10017 • • • The Sodety shall not be•responsible for statements cir opinions advanced in papers or &mission. at meetings of the Sodety or oils Dions or ' Secaone, or rend in its publications. Discussion is printed only if the paper is published in an ASME journal. Authorization to Photocopy . • for internal or personal use is granted to libraries and other users registered with the Copyright Clearance Center (CCC) provided 53/article or $4/page is paid to CCC: 222 Rosewood Dr., Danvers, MA 01923. Requests .tor special permission• • or- bulitreproduction„ • should be addressed to the ASME.Technical publishing Department. Copyright 0 1998 by ASME All Rights Reserved Downloaded from http://asmedigitalcollection.asme.org/GT/proceedings-pdf/GT1998/78637/V002T03A001/2409728/v002t03a001-98-gt-041.pdf by guest on 01 October 2021 Extending Use of Marine Gas Turbines through Application of the LM2.500+ David L. Luck GE Marine and Industrial Engines 11111111111 ,1111111111 General Electric Company Evendale, Ohio Abstract Warship Applications The propulsion configurations of current gas turbine powered military and Military ship propulsion systems commercial vessels have been established based include a variety of configurations, including the upon available power ratings of existing most commonly used combined prime mover engines, relative to the performance combinations, which are referred to as CODOG requirements of ship builders and operators. ' (COmbined Diesel Or Gas Turbine) and Development of the LM2500+ engine has COGAG (COmbined Gas turbine and Gas extended power capability with minimal Turbine). CODOG has been used where the changes to the physical parameters of the maximum power for high speed is provided by current LM2500 marine packages. This paper the gas turbines, while the low speed more explores the extended possibilities of gas turbine economical operation has been provided by based propulsion in both military and small diesels engines. For larger ships where commercial vessels through application of the maximum total power requires multiple increased gas turbine power in packages of (usually four) gas turbines, the lower speed essentially current size and weight such as the operation is provided by using a lesser number' LM2500+. of the installed engines. Background Smaller vessels (less than 2000 tons displacement) of the corvette or patrol vessel Gas turbines have become firmly classes have been able to achieve satisfactory established for marine propulsion applications performance with a single gas turbine CODOG, over the last 20 years, including extensive use in combined with multiple small diesels for low military vessels, and growing application in speed operation. CODOG propulsion specific segments of the commercial marine configurations for larger vessels (above 2000 market. The development of aeroclerivative gas tons displacement) have generally required at turbines, i.e. those derived from flying engines, least two gas turbines in order to achieve the has made efficient engines with a proven track required speed. The availability of higher power record of operation available for use in a variety marine gas turbines has the potential to extend of ship classes. use of the simpler and less expensive single gas Presented at the international Gas Turbine & Aeroengine Congress & Exhibition Stockholm, Sweden — June 2-June 5, 1998 turbine CODOG to frigate and larger size used simultaneously. For a ODGAG vessels. configuration, maximum power is generated from the combination of gas turbines. Figure 1 indicates the approximate distribution of the various configurations in Figure 1 shows no CODAG warships. (COmbined Diesel and Gas Turbine) configurations, although that alternative is now The power requirement fix various ship being implemented for the German F124 and is classes indicated in Figure 1 depends not only being considered for a number of other projects. Downloaded from http://asmedigitalcollection.asme.org/GT/proceedings-pdf/GT1998/78637/V002T03A001/2409728/v002t03a001-98-gt-041.pdf by guest on 01 October 2021 on the ship displacement but on the maximum For the CODAG configuration the total power speed required. The total power indicated on available for maximum speed becomes the sum the horizontal axis represents the maximum of the gas turbine and diesel power. For the total power available to achieve the maximum CODAG configuration, use of a larger gas speed. For a CODOG configuration, maximum turbine can extend the Single Gas Turbine power is generated from the gas turbine(s), region well into the region of Two Gas Turbine because the diesels and gas turbine(s) cannot be ship classes. Diplom Total raw•r Two arrow Gas Tortilla COO AO —7 Two . 00000 - On Turbin• CO 000 Single • •• 0•• Turblas • . • I C0000 • 000 • • 20.0 30.0 404 50.0 00.0 70.0 00.0 TeS11.0wWW.1, Figure 1 Distribution of Gas Turbine Power Plants in Warships independently drive waterjets, allowing Commercial Ship Applications simultaneous operation of both prime mover types. Multiple gas turbines are also used in the Gas turbines have only recently been COGAG configuration. Higher rated gas put to serious use in commercial ships, as the turbines offer extended capability in both compact, low weight characteristics of the commercial configurations. engines have satisfied an urgent need. The development of the fast ferry market (generally Changes in the Marine Market vessels carrying over 50 passengers at over 25 knot speed) created a growing sector of volume The range of gas turbine sizes applied sensitive ships carrying low density cargo, such in the commercial marine market has been 3 as passengers and cars, which need compact and MW to about 23 MW. Low power applications light weight propulsion systems (1,2). have generally been in very weight sensitive Similarly, cruise ships place a premium on ships such as hydrofoils. The largest efficient use of internal ship volume, and commercial ship applications have total power represent a potential application area (3). requirements of approximately 68 MW or more Commercial ship propulsion configurations also resulting in multiple gas turbine COGAG. include CODAG (Combined Diesel And Gas Commercial vessel configurations have included Turbine), where the diesels and gas turbines catamarans and monohull vessels. 2 total power is therefore the sum of that available Many catamaran vessels have been from all prime movers. The German F124 built which use two sets of propulsion systems vessels will employ CODAG with a single gas with total power less than 30 MW. The fast turbine and two diesels. Use of this same ferry trend has moved towards larger vessels concept with a more powerful gas turbine can with more capacity, operating at speeds over 40 allow propulsion of larger ships with a single knots. This trend in larger catamarans requires gas turbine, up to the size that had previously total power over 50 MW, divided into two required two gas turbines in a CODOG Downloaded from http://asmedigitalcollection.asme.org/GT/proceedings-pdf/GT1998/78637/V002T03A001/2409728/v002t03a001-98-gt-041.pdf by guest on 01 October 2021 systems for the two catamaran hulls. A arrangement. considerable advantage in volume, weight, and cost can be realized if that power can be What does the LM2500+ bring? provided by a single gas turbine in each hull. The LM2500 gas turbine has In the military marine sector, powering established a long history of operation in requirements are changing for a different military marine applications and is now being reason Instead of continued growth to larger used also in commercial marine vessels (1,2). ships with larger power requirements, a down The engine has evolved though a systematic sizing trend seems to be indicated. Instead of program of component improvements which the larger frigates, destroyers, and cruisers have increase the available power (4) and the which have dominated naval shipbuilding in maintenance and reliability (5). The available recent years, interest in vessels of the offshore power rating of the LM2500 for military marine patrol vessel and corvette size is increasing. applications is 22 MW for U. S. Navy and up to Ships of these classes normally have 23.5 MW for some other international navies displacements around 2500 tans or less, as depending upon the definition of their rating compared to the larger combatant vessels of conditions. In commercial applications with 4000 tons and larger common in earlier continuous power requirements at maximum programs. output, the LM2500 has been applied at 21 to 22 MW depending upon the condition of operation Smaller ships do not necessarily mean for the vessel. less capable ships. The operational capability requirements for these smaller ships are in some The LM2500+ development extends the ways more difficult to achieve than with larger available power while maintaining substantial ships, since the combat systems payload is commonality with the current LM2500. The extensive. In addition, the speed requirement LM2500+ will be ISO rated at 29 MW after the for these ships must usually match the capability accumulation of some operating experience with of an existing fleet. larger ships have used initial installations. The marine rating for multiple gas turbines to achieve the speed continuous operation is slightly over 26 MW for required, which is normally 30 knots or greater. ambient temperature operation at about 20° C. Small ships of 1200 ton displacement can The engine therefore provides approximately 5 achieve this speed with a single gas turbine in a MW additional power for most typical marine CODOG configuration. Ships with 2000 ton or applications. The marinized technology of the more displacement have required two gas 1242500 is carried forward in the LM2500+ turbines or have settled for diesel propulsion and with a large degree of commonality in lower speed. To maximize the payload of these components. Long experience in ship operation ships while providing the operational speed helps to ensure that LM2500+ is designed for needed, a single gas turbine CODOG systems is that environment.