scholarly journals Breaking the Barriers

2012 ◽  
Vol 134 (05) ◽  
pp. 32-37
Author(s):  
Lee S. Langston
Keyword(s):  
Fluid Mechanics ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Solid Mechanics ◽  
Commercial Aircraft ◽  
Commercial Aviation ◽  
New Developments ◽  
Exhaust Heat ◽  
Turbine Component ◽  
Made In

This article explores the new developments in the field of gas turbines and the recent progress that has been made in the industry. The gas turbine industry has had its ups and downs over the past 20 years, but the production of engines for commercial aircraft has become the source for most of its growth of late. Pratt & Whitney’s recent introduction of its new geared turbofan engine is an example of the primacy of engine technology in aviation. Many advances in commercial aviation gas turbine technology are first developed under military contracts, since jet fighters push their engines to the limit. Distributed generation and cogeneration, where the exhaust heat is used directly, are other frontiers for gas turbines. Work in fluid mechanics, heat transfer, and solid mechanics has led to continued advances in compressor and turbine component performance and life. In addition, gas turbine combustion is constantly being improved through chemical and fluid mechanics research.

scholarly journals Changing the Game

2008 ◽  
Vol 130 (05) ◽  
pp. 25-29
Author(s):  
Lee S. Langston
Keyword(s):  
Gas Turbine ◽  
Airline Industry ◽  
Gas Turbines ◽  
Jet Engines ◽  
Commercial Aircraft ◽  
Commercial Aviation ◽  
Steady Growth ◽  
Military Aviation ◽  
Electrical Generation ◽  
Future Growth

This article reviews potentially radical advances in gas turbines that came in all shapes and sizes in 2007. Gas turbine production is now a $30 billion industry, one that has been dominated, except for a stretch in the late 1990s, by commercial and military aviation. In its 70-year history, the gas turbine has become one of society’s most important and versatile energy conversion, which is relatively inert. Fuel converted to power through a gas turbine is as kinetic a substance as you can find, and one that can create great wealth. In the $21.8 billion aviation market, nearly 80 percent is for commercial aircraft engines, while the dominance of electrical generation in the $10.5 billion non-aviation market is even greater. New aircraft represents advances for commercial aviation, but commercial jet engines are themselves the key to future growth of the airline industry. While the aviation market has seen steady growth over the past decade or so, the non-aviation market for gas turbines has a noticeable production spike.

Some Effects of Size on the Performances of Small Gas Turbines

2003 ◽  
Author(s):  
C. Rodgers
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Engine Performance ◽  
Lessons Learned ◽  
Rapid Expansion ◽  
Cycle Performance ◽  
Frictional Drag ◽  
Component Design ◽  
Turbine Component ◽  
Performance Development

By the new millennia gas turbine technology standards the size of the first gas turbines of Von Ohain and Whittle would be considered small. Since those first pioneer achievements the sizes of gas turbines have diverged to unbelievable extremes. Large aircraft turbofans delivering the equivalent of 150 megawatts, and research micro engines designed for 20 watts. Microturbine generator sets rated from 2 to 200kW are penetrating the market to satisfy a rapid expansion use of electronic equipment. Tiny turbojets the size of a coca cola can are being flown in model aircraft applications. Shirt button sized gas turbines are now being researched intended to develop output powers below 0.5kW at rotational speeds in excess of 200 Krpm, where it is discussed that parasitic frictional drag and component heat transfer effects can significantly impact cycle performance. The demarcation zone between small and large gas turbines arbitrarily chosen in this treatise is rotational speeds of the order 100 Krpm, and above. This resurgence of impetus in the small gas turbine, beyond that witnessed some forty years ago for potential automobile applications, fostered this timely review of the small gas turbine, and a re-address of the question, what are the effects of size and clearances gaps on the performances of small gas turbines?. The possible resolution of this question lies in autopsy of the many small gas turbine component design constraints, aided by lessons learned in small engine performance development, which are the major topics of this paper.

Combined Heat and Power: Gas Turbine Operational Flexibility

2013 ◽  
Author(s):  
James DiCampli
Keyword(s):  
Gas Turbine ◽  
Urban Areas ◽  
Gas Turbines ◽  
Heat Recovery ◽  
National Fire Protection Association ◽  
Combined Heat And Power ◽  
Combined Cycle ◽  
Electricity Production ◽  
Exhaust Heat ◽  
Gas Fuel

Combined heat and power (CHP) is an application that utilizes the exhaust heat generated from a gas turbine and converts it into a useful energy source for heating & cooling, or additional electric generation in combined cycle configurations. Compared to simple-cycle plants with no heat recovery, CHP plants emit fewer greenhouse gasses and other emissions, while generating significantly more useful energy per unit of fuel consumed. Clean plants are easier to permit, build and operate. Because of these advantages, projections show CHP capacity is expected to double and account for 24% of global electricity production by 2030. An aeroderivative power plant has distinct advantages to meet CHP needs. These include high thermal efficiency, low cost, easy installation, proven reliability, compact design for urban areas, simple operation and maintenance, fuel flexibility, and full power generation in a very short time period. There has been extensive discussion and analyses on modifying purge requirements on cycling units for faster dispatch. The National Fire Protection Association (NFPA) has required an air purge of downstream systems prior to startup to preclude potentially flammable or explosive conditions. The auto ignition temperature of natural gas fuel is around 800°F. Experience has shown that if the exhaust duct contains sufficient concentrations of captured gas fuel, and is not purged, it can ignite immediately during light off causing extensive damage to downstream equipment. The NFPA Boiler and Combustion Systems Hazards Code Committee have developed new procedures to safely provide for a fast-start capability. The change in the code was issued in the 2011 Edition of NFPA 85 and titled the Combustion Turbine Purge Credit. For a cycling plant and hot start conditions, implementation of purge credit can reduce normal start-to-load by 15–30 minutes. Part of the time saving is the reduction of the purge time itself, and the rest is faster ramp rates due to a higher initial temperature and pressure in the heat recovery steam generator (HRSG). This paper details the technical analysis and implementation of the NFPA purge credit recommendations on GE Power and Water aeroderivative gas turbines. This includes the hardware changes, triple block and double vent valve system (or drain for liquid fuels), and software changes that include monitoring and alarms managed by the control system.

Experience With Mobile Gas Turbines

1963 ◽  
Author(s):  
R. Artigas ◽  
E. Bernhardt
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
The Third ◽  
Made In

The Comision Federal de Electricidad of Mexico in 1954 ordered two mobile gas-turbine sets; an additional identical set was ordered in 1955. The first two units went into service in 1955 and the third in 1956. Therefore, all three units have been operated for more than 6 years. This paper reviews briefly the operation data and the difficulties and problems involved. Finally, a few remarks are made in relation to future use of similar units.

Enhanced Gas Turbine Combustor Performance Using H2-Enriched Natural Gas

1999 ◽  
Author(s):  
Jeffrey N. Phillips ◽  
Richard J. Roby
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Flame Speed ◽  
Gas Turbine Combustor ◽  
Flammability Limits ◽  
Combustion Performance ◽  
Exhaust Heat ◽  
Efficient Combustion

A screening level study has been carried out to examine the potential of using H2-enriched natural gas to improve the combustion performance of gas turbines. H2 has wider flammability limits and a higher flame speed than methane. Many previous studies have shown that when H2 is added to fuel, more efficient combustion and lower emissions will result. However, to date no commercial attempt has been made to improve the combustion performance of a natural gas-fired gas turbine by supplementing the fuel with H2. Four potential options for supplementing natural gas with H2 have been analyzed. Three of these options use the exhaust heat of the gas turbine either directly or indirectly to partially reform methane. The fourth option uses liquid H2 supplied from an industrial gas producer.

Aeroderivative Combined Heat and Power Fundementals and Applications

2012 ◽  
Author(s):  
James DiCampli
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Energy System ◽  
Combined Heat And Power ◽  
Combined Cycle ◽  
Draft Guidance ◽  
Distributed Energy ◽  
Improve Energy Efficiency ◽  
Exhaust Heat

Combined heat and power (CHP), is an application that utilizes the exhaust heat generated from a gas turbine and converts it into a useful energy source for heating & cooling, or additional electric generation in combined cycle configurations. Compared to simple-cycle plants with no heat recovery, CHP plants emit fewer greenhouse gasses and other emissions, while generating significantly more useful energy per unit of fuel consumed. Clean plants are easier to permit, build and operate. Because of these advantages, Aeroderivative gas turbines will be a major part of global CHP growth, particularly in China. In order to improve energy efficiency and reduce CO2 emissions, China is working to build ∼1000 new plants of Natural Gas Distributed Energy System (NG-DES) in the next five years. These plants will replace conventional coal-fired plants with combined cooling, heating and power (CCHP) systems. China power segments require an extensive steam supply for cooling, heating and industrial process steam demands, as well as higher peak loads due to high population densities and manufacturing growth rates. GE Energy Aero recently entered the CCHP segment in China, and supported the promotion of codes and standards for NG-DES policy, and is developing optimized CCHP gas turbine packages to meet requirements. This paper reviews those policies and requirements, and presents technical case studies on CCHP applications. Appendix B highlights China’s draft “Guidance Opinions on Developing Natural-Gas Distributed Energy.”

scholarly journals Effects of Alloy Composition on the Performance of Yttria Stabilized Zirconia–Thermal Barrier Coatings

1999 ◽  
Author(s):  
Josh Kimmel ◽  
Zaher Mutasim ◽  
William Brentnall
Keyword(s):  
Gas Turbine ◽  
Thermal Barrier Coatings ◽  
Gas Turbines ◽  
Base Alloy ◽  
Critical Factor ◽  
Thermal Barrier ◽  
Barrier Coatings ◽  
Turbine Component ◽  
Industrial Gas Turbines ◽  
Materials Used

Thermal barrier coatings (TBCs) provide an alloy surface temperature reduction when applied to turbine component surfaces. Thermal barrier coatings can be used as a tool for the designer to augment the power and/or enhance the efficiency of gas turbine engines. TBCs have been used successfully in the aerospace industry for many years, with only limited use for industrial gas turbine applications. Industrial gas turbines operate for substantially longer cycles and time between overhauls, and thus endurance becomes a critical factor. There are many factors that affect the life of a TBC including the composition and microstructure of the base alloy and bond coating. Alloys such as Mar-M 247, CMSX-4 and CMSX-10 are materials used for high temperature turbine environments, and usually require protective and/or thermal barrier coatings for increased performance. Elements such as hafnium, rhenium, and yttrium have shown considerable improvements in the strength of these alloys. However these elements may result in varying effects on the coatability and environmental performance of these alloys. This paper discusses the effects of these elements on the performance of thermal barrier coatings.

Fuel Efficiency Improvements in U.S. Navy Gas Turbine Systems

1984 ◽  
Author(s):  
Eugene F. Brady
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Waste Heat ◽  
Fuel Efficiency ◽  
Rankine Cycle ◽  
Component Technology ◽  
General Description ◽  
Hardware System ◽  
Recovery System ◽  
Turbine Component

Major efforts are currently underway to improve the fuel consumption efficiency of gas turbines for powering of U.S. Navy surface ships. Recent efforts have focused on efficiency improvement by the recovery of waste heat, in system enhancements such as the RACER (Rankine Cycle Energy Recovery) system. More recently, however, consideration is also being given to the use of a recuperator (and possibly an intercooler) to improve basic gas turbine thermal efficiency. Furthermore, a third approach is to improve efficiency by enhancements in basic gas turbine component technology. In this paper, current activity and progress in each of these three systems concepts are presented. First, the ship design benefits resulting from improved fuel efficiency will be described. Following this, programs in each of the above three categories are presented. This includes a general description of the hardware system, and the major performance characteristics. Finally, appropriate comparisons of these three approaches are made. These include projected fuel efficiency improvements, and the required ship space and weight. Projected future developments are also described.

Gas Turbines For Helicopters

1958 ◽  
Vol 62 (573) ◽  
pp. 646-654 ◽  
Author(s):  
A. W. Morley
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Liquid Fuel ◽  
Korean War ◽  
Turbine Engines ◽  
Gradual Improvement ◽  
Turbine Engine ◽  
Civil Aircraft ◽  
The Korean War ◽  
Made In

Rapid developments in the use of the helicopter were made in the Korean War. These were taking place at the time when there was considerable urge to introduce the gas turbine engine into the civil aircraft market. It was also a time when much effort was being expended on various forms of reaction propulsion, mostly for missiles. A number of new helicopter projects were started, taking advantage of the new knowledge in propulsion engineering; some utilised new gas turbine designs and others various forms of tip jet reaction. Liquid fuel rockets, ram-jets, pulse-jets and air pressure jets were tried. However, the main line of development continued to be the gradual improvement of direct mechanical drive.Since Korea the natural trend has been first to convert existing helicopters to turbine engines. When new helicopters were designed wisdom dictated mechanical drive pending the gathering of sufficient experience with other forms of rotor power, and so far the accumulated knowledge of the mechanical drive has proved of greater value to helicopter progress than the potential advantages offered by the alternative engine forms.

scholarly journals Anticipated but Unwelcome

2018 ◽  
Vol 140 (06) ◽  
pp. 37-41 ◽  
Author(s):  
Lee S. Langston
Keyword(s):  
Airline Industry ◽  
Gas Turbines ◽  
New Technology ◽  
Commercial Aircraft ◽  
Commercial Aviation ◽  
Commercial Airline ◽  
Swing Engine ◽  
Full Swing ◽  
Executive Careers ◽  
Roll Out

This article provides the latest trends in the gas turbines market and their future outlook. The last three years of operation have generated more profit for the commercial airline industry than the previous 30 years combined. That money has led to new orders for commercial aircraft and as a result, production of commercial aviation gas turbines is in full swing. Engine manufacturers such as Pratt&Whitney, Rolls-Royce, General Electric, Safran, and others have taken this surge in orders as an incentive to develop new technology. The launch of a new jet engine by a manufacturer can be a multi-billion dollar effort. Financial projections and executive careers hang on a smooth roll-out of the new technology.

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