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.

EVITA Study: Evaluation of Unscheduled Aircraft and Industrial Gas Turbine Part Failure Cases

2008 ◽  
Author(s):  
Gerrit Kool ◽  
Jacques van den Elshout ◽  
Eric Vogelaar ◽  
Ron van Gestel ◽  
Andre´ Mom
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Contributing Factors ◽  
Root Cause ◽  
Component Design ◽  
Design Changes ◽  
Study Evaluation ◽  
Turbine Component ◽  
Industrial Gas Turbine ◽  
Original Component

Maintenance costs of gas turbines are mainly driven by replacement costs of expensive parts. Reconditioning of these parts is considered to decrease the costs significantly, but it is the impression that re-used parts tend to be more involved in part failures. This is sometimes related to microstructural changes in the substrate materials owing to part repair. One hundred and nine (109) unscheduled gas turbine component failure cases have been collected and analyzed to identify causes of failure and contributing factors, and also to provide guidance on corrective measures such as design changes, new repair methods, missing information links and future R&D efforts. It was found that the most frequently reported failure mechanisms are mechanical and thermal fatigue and changes in the microstructure. Fifty percent (50%) of the reported failure cases have a root cause in the original component design and repair design, and consequently permanent solutions can be achieved by design modifications only. The paper concludes with the identification of knowledge gaps.

scholarly journals Ceramic Composites for Industrial Gas Turbine Engine Applications: DOE CFCC Phase 1 Evaluations

1995 ◽  
Author(s):  
Gregory S. Corman ◽  
Jeffrey T. Heinen ◽  
Raymond H. Goetze
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Phase 1 ◽  
Engine Performance ◽  
Ceramic Composites ◽  
Gas Turbine Engine ◽  
Turbine Engine ◽  
Performance Improvements ◽  
Component Design ◽  
Industrial Gas Turbine

Conceptual design evaluations of the use of continuous fiber ceramic composite (CFCC) turbine shrouds and combustor liners in an industrial gas turbine engine were performed under Phase 1 of the DOE CFCC program. Significant engine performance improvements were predicted with the use of CFCC components. Five composite systems were evaluated for use as shrouds and combustor liners, the results of which are discussed with particular reference to Toughened Silcomp. Several current CFCC materials were judged to be relatively close to meeting the short term performance requirements of such a system. However, additional CFCC property data are required for significant component design optimization and life prediction, two key design steps that must be completed before ceramic composites can be utilized in large gas turbines.

Small Recuperated Gas Turbine APU Concept to Abate Concern About Emissions, High Fuel Cost, and Noise

2007 ◽  
Author(s):  
Colin Rodgers ◽  
Colin F. McDonald
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Engine Performance ◽  
High Volume ◽  
Cold Weather ◽  
Modular Construction ◽  
Fuel Cost ◽  
Climate Control ◽  
Component Design ◽  
The Usa

During the last decade microturbines in the 30 to 250 kW power range have been in service, but they have not been produced in significant enough quantities to impact the DG market due to a combination of factors including their high cost, modest efficiency, utility institutional concerns, and low interest in CHP use in the USA, although the latter could change as a result of fuel cost escalation. Very small gas turbines (ie. less than 10 kW) have been investigated periodically over the years, mainly for potential military use, but to date have not found a niche. This could well change with over 20 states now having instigated idling regulations that limit or prohibit heavy duty truck diesel engine idling. With emphasis on reducing emissions and noise levels this essentially implies that in the future a small APU will be required to provide the truck’s stationary electrical needs and cabin climate control. While there will be several power source types vying for this potentially large market, a small gas turbine APU is viewed as having attractive features which include low emissions, low acoustic signature, vibration-free operation, compact and light weight package, obviates the need for oil lubrication and liquid coolant systems, ease of cold weather starting, immediate response, and the use of fuel from the truck tank. In this paper a small recuperated gas turbine APU concept rated at 5kW is discussed including component design considerations, layout features, engine performance, and target cost. The conservative design of the APU is based on the use of existing materials and state-of-the-art gas turbine technology, and is amenable to high volume automated manufacturing processes. A competitive cost is projected if the proposed APU of modular construction was fabricated in large quantities like the production of vehicular turbochargers in Europe.

scholarly journals Feasibility of a Helium Closed-Cycle Gas Turbine for UAV Propulsion

2020 ◽  
Vol 11 (1) ◽  
pp. 28
Author(s):  
Emmanuel O. Osigwe ◽  
Arnold Gad-Briggs ◽  
Theoklis Nikolaidis
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Pressure Ratio ◽  
Low Noise ◽  
Closed Cycle ◽  
Propulsion Systems ◽  
Component Design ◽  
Readiness Level ◽  
Aerial Vehicle ◽  
Turbine Design

When selecting a design for an unmanned aerial vehicle, the choice of the propulsion system is vital in terms of mission requirements, sustainability, usability, noise, controllability, reliability and technology readiness level (TRL). This study analyses the various propulsion systems used in unmanned aerial vehicles (UAVs), paying particular focus on the closed-cycle propulsion systems. The study also investigates the feasibility of using helium closed-cycle gas turbines for UAV propulsion, highlighting the merits and demerits of helium closed-cycle gas turbines. Some of the advantages mentioned include high payload, low noise and high altitude mission ability; while the major drawbacks include a heat sink, nuclear hazard radiation and the shield weight. A preliminary assessment of the cycle showed that a pressure ratio of 4, turbine entry temperature (TET) of 800 °C and mass flow of 50 kg/s could be used to achieve a lightweight helium closed-cycle gas turbine design for UAV mission considering component design constraints.

Design, Development and Application of Vehicle Gas Turbine Engines

1966 ◽  
Vol 181 (1) ◽  
pp. 149-172
Author(s):  
P. A. Phillips ◽  
Peter Spear
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Low Cost ◽  
Engine Performance ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Design Development ◽  
Turbine Engine ◽  
Wide Range ◽  
Cycle Temperature

After briefly summarizing worldwide automotive gas turbine activity, the paper analyses the power plant requirements of a wide range of vehicle applications in order to formulate the design criteria for acceptable vehicle gas turbines. Ample data are available on the thermodynamic merits of various gas turbine cycles; however, the low cost of its piston engine competitor tends to eliminate all but the simplest cycles from vehicle gas turbine considerations. In order to improve the part load fuel economy, some complexity is inevitable, but this is limited to the addition of a glass ceramic regenerator in the 150 b.h.p. engine which is described in some detail. The alternative further complications necessary to achieve satisfactory vehicle response at various power/weight ratios are examined. Further improvement in engine performance will come by increasing the maximum cycle temperature. This can be achieved at lower cost by the extension of the use of ceramics. The paper is intended to stimulate the design application of the gas turbine engine.

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 Impact of compressed air energy storage demands on gas turbine performance

2020 ◽  
pp. 095765092090627 ◽  
Author(s):  
Uyioghosa Igie ◽  
Marco Abbondanza ◽  
Artur Szymański ◽  
Theoklis Nikolaidis
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Pressure Ratio ◽  
Engine Performance ◽  
Compressed Air ◽  
Design Stage ◽  
Simulation Code ◽  
Ratio Distribution ◽  
Stall Margin ◽  
Industrial Gas Turbines

Industrial gas turbines are now required to operate more flexibly as a result of incentives and priorities given to renewable forms of energy. This study considers the extraction of compressed air from the gas turbine; it is implemented to store heat energy at periods of a surplus power supply and the reinjection at peak demand. Using an in-house engine performance simulation code, extractions and injections are investigated for a range of flows and for varied rear stage bleeding locations. Inter-stage bleeding is seen to unload the stage of extraction towards choke, while loading the subsequent stages, pushing them towards stall. Extracting after the last stage is shown to be appropriate for a wider range of flows: up to 15% of the compressor inlet flow. Injecting in this location at high flows pushes the closest stage towards stall. The same effect is observed in all the stages but to a lesser magnitude. Up to 17.5% injection seems allowable before compressor stalls; however, a more conservative estimate is expected with higher fidelity models. The study also shows an increase in performance with a rise in flow injection. Varying the design stage pressure ratio distribution brought about an improvement in the stall margin utilized, only for high extraction.

Gas Turbine Fouling Offshore: Effective Online Water Wash Through High Water-to-Air Ratio

2018 ◽  
Vol 141 (4) ◽  
Author(s):  
Stian Madsen ◽  
Lars E. Bakken
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Peak Load ◽  
Engine Performance ◽  
High Water ◽  
Operational Experience ◽  
Successful Operation ◽  
Water Rate ◽  
Offshore Field ◽  
Key Parameter

Optimized operation of gas turbines is discussed for a fleet of 11 GE LM2500PE engines at a Statoil North Sea offshore field in Norway. Three engines are generator drivers, and eight engines are compressor drivers. Several of the compressor drive engines are running at peak load (T5.4 control), hence, the production rate is limited by the available power from these engines. The majority of the engines discussed run continuously without redundancy, hence, the gas turbine uptime is critical for the field's production and economy. The performance and operational experience with online water wash at high water-to-air ratio (w.a.r.), as well as successful operation at longer maintenance intervals and higher average engine performance are described. The water-to-air ratio is significantly increased compared to the original equipment manufacturer (OEM) limit (OEM limit is 17 l/min which yields approximately 0.5% water-to-air ratio). Today the engines are operated at a water rate of 50 l/min (three times the OEM limit) which yields a 1.4% water-to-air ratio. Such a high water-to-air ratio has been proven to be the key parameter for obtaining good online water wash effectiveness. Possible downsides of high water-to-air ratio have been thoroughly studied.

scholarly journals Combined Gas Turbine and Diesel Generator Cooling Air Intake System

1998 ◽  
Author(s):  
Roger Yee ◽  
Alan Oswald
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Lessons Learned ◽  
Aviation Fuel ◽  
Diesel Generator ◽  
Intake System ◽  
Air Intake ◽  
New Generation ◽  
Cooling Air ◽  
The U.S

A new generation of auxiliary ships to enter the U.S. Navy (USN) fleet is the AOE-6 SUPPLY CLASS. These fast combat support ships conduct operations at sea as part of a Carrier Battle group to provide oil, aviation fuel, and ammunition to the carrier and her escorts. The SUPPLY CLASS is the first ship in the entire USN fleet to use a combined gas turbine and diesel generator cooling air intake system to cool its respective engine modules. The cooling air intake was designed this way to save on costs. As the ships in this class continued with operations and problems of insufficient supply of cooling air for the gas turbines modules started surfacing, the entire intake system required investigation and analysis. Since the gas turbines and diesel generators share a common cooling air trunk, they were competing for air. This paper will outline the tests that were performed to determine the problems, the recommended solutions, and the lessons learned from the investigations.

A Novel and Compact Marine Gas Turbine Propulsion System

1998 ◽  
Author(s):  
Panteleimon Kazatzis ◽  
Riti Singh ◽  
Pericles Pilidis ◽  
Jean-Jacques Locquet
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
High Speed ◽  
Engine Performance ◽  
Simple Cycle ◽  
Flow Conditions ◽  
Part Load ◽  
The Poor ◽  
Full Power ◽  
The One

The power-speed requirements of warships and the poor part load efficiency of simple cycle gas turbines has given rise to the design of many ship installations where two types of gas turbines are used. A large type for high speed, at full power, and a small one for cruise. It is common to mount two units of each type. This design results in a large amount of bulky and heavy ducting, much more voluminous and heavy than the gas turbines themselves. The present paper outlines an investigation into a novel intercooled split-cycle with some deck mounted components. This reduces the requirement for internal ducts in the ships hull, essentially, to those needed by the cruise engine. The engine performance has been predicted and a comparison is carried out between a traditional installation and the one investigated. An estimate has been carried out of the flow conditions of the duct to assess the change in losses for operation in the cruise and the full power condition. The new scheme appears to be promising.

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