bluuebunny/crossref_metadata_2025 huggingface dataset:
Net Shape Components for Small Gas Turbine Engines
Authors: Schimmel W. P. , Quill G. J.
Published: April 2015

Small gas turbine engine manufacturers, with Armed Services support, are utilizing advanced manufacturing technology programs to incorporate net shaped components into both the current and the next generation of small high performance gas turbine engines. A coordinated program is underway to provide near-net shaped components which will minimize machining costs, save critical materials, and in some cases provide increased component capabilities. These programs include isothermal forging of titanium, casting of titanium, HIP’ed titanium powder metal techniques, diffusion bonded dual property approaches, and a diffuser case fabrication process. The manufacturing technologies presented in this paper are currently being targeted for small gas turbine engines.
Evaluation of Gas Turbine Bucket Corrosion Protection Systems Following Long-Time Service in Saudi Arabia
Authors: Wood J. H. , Schilling W. F. , Aeschbacher H. J.
Published: April 2015

This paper describes the ongoing results being obtained from a joint General Electric/ARAMCO program to improve gas turbine bucket corrosion lives in desert environments involving high concentrations of alkali salts and sulfur-containing fuels. The program has involved the insertion of buckets coated with a variety of experimental or developmental coatings into several General Electric MS-5002 gas turbines being operated by ARAMCO in the Eastern Province of Saudi Arabia. Buckets coated by a variety of process techniques, such as pack cementation, physical vapor deposition, plasma spray and sheet cladding, have been evaluated during this program. Service life on some of these coated buckets has now reached approximately 35,000 hr. In general, Pt-Cr-Al pack cementation coatings have been observed to perform well, with the Pt being critical for superior long-time service.
Racer: The Contractor’s View
Authors: Halkola John T.
Published: April 2015

The RACER (RAnkine Cycle Energy Recovery) system has progressed from a technical feasibility investigation, through a competitive preliminary design phase and is now a major research and development program. Transition to a specific ship application is becoming more likely as milestones are accomplished. There are several views of any program: the sponsor’s, the contractor’s, the test facility’s and the ultimate user’s. This paper summarizes the contractor’s view.
The Effect of Electrostatic Spray Modification on Combustion in Gas Turbines
Authors: Miller J. A. , Biblarz O. , Zajdman A. , Manning W. W. , Mavroudis J. A.
Published: April 2015

The feasibility of using electrostatic or electrohydrodynamic fields as a practical means of altering gas turbine injector spray characteristics has been investigated. Results indicate that with accelerating potentials typical of sparkplug voltages sufficient modification of spray characteristics is produced to suggest a means for reoptimization of combustor performance when fuels other than that for which a given combustor has been designed must be burned.
The Effect of Thermal Transients on Radial Turbine Blade Vibration Damping: A Case Study
Authors: Næss Tore , Teien Kjell O.
Published: April 2015

Since the Kongsberg KG5 gas turbine was introduced into service in 1977 these engines have accumulated more than 100 000 hours of field operation. Apart from an exducer blade vibration problem which was revealed and fixed prior to field introduction, no major operational problems have been encountered.

During test and commissioning of two larger orders, three separate incidents of turbine blade failure occurred, one in March 1982 and two in February 1983. The first incident triggered a number of investigative actions and the resulting conclusion was confirmed by the last two incidents.

The present paper describes the analytical and test methods employed in order to investigate this problem. The blade natural frequencies were determined analytically through a NASTRAN analysis and experimentally with a TV-Speckle Interferometer technique.

It is shown how the influence of an interference fit or dampening joint between the two rotor wheels was actually hiding the possible resonance condition during the initial qualification tests, and how the transient movements of this joint would allow resonance to occur under certain operational conditions.

The possible corrective modifications are discussed and the selected solution is shown. The test set up and the results from the verifying strain gauge test is presented.
Comparative Analysis of Gas Turbine Systems for Pressure Energy Recovery From Blast Furnace Gas
Authors: Guizzi Giuseppe Leo
Published: April 2015

Modern high capacity blast furnaces are generally operated at high values of back pressure at the top of the furnace (250÷400 kPa abs.). In order to recover this large quantity of pressure energy some turbine equipments have been recently developed. The possible solutions of these systems must take into account the clean up outcoming blast furnace gas conditions (cold and water saturated gas).

Up-to-date solution analysis has carried to three different main process types: wet expansion; dry expansion by partial burning of gas; dry expansion by gas heating in a heat exchanger.

This paper develops an energy based analysis for these equipments taking into account not only the recovery in the turbine unit, but also the effect of this equipment on the whole integrated system “blower - cowpers - blast furnace - gas turbine unit - power conversion station”.

A parametric analysis is performed and the obtained results are presented and discussed.
Cascade Heat Transfer Tests of the Air Cooled W501D First Stage Vane
Authors: Tobery E. Wayne , Bunce Richard H.
Published: April 2015

A full scale, three vane, four passage, first stage stator segment from a Westinghouse W501D engine was tested in the vane cooling cascade rig at the Combustion Turbine Systems Division Development Center in Concordville, Pennsylvania. The cascade facility operates with air preheated to engine compressor discharge conditions, and it is fired with a standard combustor and nozzle assembly so that engine design vane inlet temperatures and pressures may be obtained with realistic free stream turbulence levels. The vanes are cooled internally by impingement inserts over most of the surface, and with pin fins in the trailing edge region. External film cooling is introduced by discrete jets over most of the suction surface and over the aft portion of the pressure surface. The flow to each insert was individually controlled and measured for the test.

Tests were run over a range of cascade pressures, temperatures, and Reynolds’ numbers. The vanes were instrumented to obtain metal temperatures, internal cooling air temperatures and pressures, and gas path static pressure near the film cooling holes. Measured metal temperatures were compared to analytical predictions over the range of test conditions. Since internal heat transfer relations had been obtained by model tests, a good correlation between measured and predicted temperatures verified the gas path side heat transfer coefficients used in the design and analysis.
Off-Design and Part-Load Behaviour of PFBC Combined Cycle Power Plant
Authors: Pillai K. K. , Roberts A. G.
Published: April 2015

Combined cycle power plant utilising pressurised fluidised bed coal combustors (PFBCs) have, of necessity, to be designed to suit the particular gas turbine chosen. The gas turbine characteristics set not only the design point but also the turndown available. The interactions between the gas cycle, the combustor and the steam cycle are different to those normally associated with combined cycle plant.

This paper describes the methods available when designing for plant operation at off-design conditions. It is shown how available techniques are capable of meeting commercial plant requirements for start-up, rates of load change and turndown.
The MIT Blowdown Turbine Facility
Authors: Epstein A. H. , Guenette G. R. , Norton R. J. G.
Published: April 2015

A short duration (0.4 sec) test facility, capable of testing 0.5-meter diameter, film-cooled, high work aircraft turbine stages at rigorously simulated engine conditions has been designed, constructed, and tested. The simulation capability of the facility extends up to 40 atm inlet pressure at 2500°K (4000°F) turbine inlet temperatures. The facility is intended primarily for the exploration of unsteady, three-dimensional fluid mechanics and heat transfer in modern turbine stages.
Indirect Fired Gas Turbine Cogeneration Using Petroleum Coke Fired AFBC Air Heater
Authors: Stäb F. P. , Moskowitz S.
Published: April 2015

A cogeneration plant based on a Combined Cycle (C.C.) system offers advantages especially when an in-expensive fuel can be used. Petroleum coke as a by-product solid fuel with high sulfur content can be fired in an Atmospheric Fluid Bed Combustion Air Heater (AFBC-AH) to provide indirect heating of the compressor discharge air flow of the gas turbine in such a C.C. system, which produces electric power and process steam in an efficient and environmentally clean manner.

This paper describes (a) the overall system and some major components, (b) system performance and (c) the economics of such a plant for an application on a site, where petroleum Coke is already used as raw material in the industrial process.

The paper shows that for this particular application the C.C. cogeneration plant with a petroleum coke fired AFB air heater can be competitive when compared with the natural gas or liquid fuel fired cogeneration plant. In addition, this plant will generate less emissions than generally achieved in solid fuel fired cogeneration plants.
Design of Gas Turbine Exhaust Heat Recovery Boiler Systems
Authors: Eriksen V. L. , Froemming J. M. , Carroll M. R.
Published: April 2015

Heat recovery boilers utilizing the exhaust from gas turbines continue to be viable as industrial cogeneration systems. This paper outlines the types of heat recovery boilers available for use with gas turbines (1–100 MW). It discusses the design and performance criteria for both unfired and supplementary fired gas turbine exhaust heat recovery boilers of single and multiple pressure levels. Equations to assist in energy balances are included along with design features of heat recovery system components. The economic incentive to achieve the maximum practical heat recovery versus the impact on boiler design and capital cost are examined and discussed. It is intended that the information presented in this paper will be of use to individuals who are not intimately familiar with gas turbine heat recovery systems so that they can better specify and evaluate potential systems.
Shear Layer Mixing for Low Emission Gas Turbine Primary Zones
Authors: Al-Dabbagh N. A. , Andrews G. E. , Manorharan R.
Published: April 2015

Shear layer turbulent fuel and air mixing has been utilised in a simulated gas turbine primary zone combustor. Two methods of fuel injection and two values of the number of air injection holes have been investigated at a constant pressure loss of 4% at a reference Mach number of 0.047. The method of fuel injection and the number of air injection holes was found to influence the flame stability and NOx emissions. A large number of holes produced much higher NOx emissions which was not compensated for by the ability to operate at weaker equivalence ratios due to the greater flame stability. An optimum primary zone operating condition, for very low NOx and high combustion efficiencies involving a flame temperature of approximately 1600K was identified and there was a wide flame stability margin on this condition.
The Integrated Gas/Steam Nozzle With Steam Cooling: Part I — Application
Authors: Rice Ivan G.
Published: April 2015

The integration of multiple steam nozzles with the first-stage annular-gas nozzle to form a binary-flow system in a reheat-gas turbine is presented whereby steam is first used as an internal vane coolant before being expanded and accelerated for work extraction. Steam nozzles are located in “fat-body” type vanes. Trailing-edge impingement followed by reverse-serpentine-flow cooling takes place. Internal trailing-edge-steam nozzles produce either diffusion or shock-wave boundary-layer disturbance inside the trailing edge to enhance heat transfer. Externally, steam blanketing reduces nozzle-profile loss and improves film cooling effectiveness by reducing the surface viscosity and secondly by controlling suction-side aft-shock-wave development. A new vane shape coupled with a gas-turning-combustor system is suggested to improve vane-film-cooling effectiveness further.
A Microprocessor Based Laser-Doppler Vibration Probe
Authors: Brown A. D. , Cookson R. A.
Published: April 2015

The laser-Doppler, fibre-optic probe which has been developed at Cranfield and which can be used for the non-intrusive detection and measurement of mechanical vibration, has been improved optically and by the inclusion of a microprocessor system to replace the previously employed frequency tracker and Bragg cells. These improvements facilitate the manufacture of a laser-Doppler probe which is more compact and considerably cheaper than the previous version, and which has potential for the application of a wide range of signal processing techniques.
Seven Years of Putnam Plant Operation: Part 1–2
Authors: Tandon V. C. , Moss D. A.
Published: April 2015

Florida Power and Light Company’s Putnam Station, one of the most efficient power plants in the FP&L system, is in a unique and enviable position from an operational viewpoint. Its operation, in the last seven years, has evolved through a triple phase fuel utilization from distillate to residual oil and finally to natural gas. This paper compares the availability/reliability of the Putnam combined cycle station and the starting reliability of the combustion turbines in each of the operating periods. A review of the data shows that high availability/reliability is not fuel selective when appropriate actions are developed and implemented to counteract the detractors. This paper also includes experience with heat rate and power degradation of various power plant components and programs implemented to restore performance.
The Effect of Oxygen Concentration on Ignition of Fuel Spray in Low Pressure Air Flow
Authors: Zhao Y. H. , Chen N. K. , Chin J. S.
Published: April 2015

Further experimental research has been carried out on the ignition improvement by oxygen addition in a small pilot combustion chamber taken from an existing aero-engine. Both uniform mixture method and local oxygen injection method have been investigated. The results show that oxygen addition improves low pressure ignition performance significantly. Local oxygen injection makes much better use of oxygen added. Experimental results show low evaporation percentage of fuel spray responsible for the poor ignition performance. Based on thermal ignition theory, a semi-analytical equation has been obtained to predict the relative enlargement of maximum ignition velocity by oxygen addition, the equation can correlate experimental data very well. To form a stagnant region with suitable oxygen concentration is the most important factor in the design of ignitor with oxygen addition.
Experimental Study of the Flow Field Behind an Annular Turbine Nozzle Guide Vane With and Without Downstream Rotor
Authors: Boletis E. , Sieverding C. H.
Published: April 2015

Measurements of the three dimensional flow field in annular turbine nozzle guide vanes present an important step in the simulation of the real flow conditions in turbomachinery bladings. This paper seeks to determine whether the installation of a rotor closely behind a high hub-to-tip ratio cascade (DH/DT=0.8) is indispensable for establishing correct flow conditions at the cascade exit or whether the use of an axial diffuser of a certain length is sufficient. Also, an attempt is made to separate the possible effects of the rotor blades from that of the rotating rotor disc.

The tests are carried out on a low speed, low aspect ratio, high turning nozzle guide vane. The flow is explored by means of a double head four-hole pressure probe and the results are presented in the form of contour plots and spanwise pitch-averaged distributions of losses, flow angles and static pressure.
Design and Testing of a 45 HW Gas Turbine
Authors: Wicki A. , Farkas F.
Published: April 2015

A new medium size gas turbine in the 45 MW range (Type 8) has been designed, manufactured and tested. Although the components that have proven to be successful over years of practical experience were kept, definite improvements with respect to the thermodynamic process have been achieved.

All new components were designed with the help of the latest analytical equipment. Major components were tested separately and on models built to scale.

To test the entire machine, a power plant equipped with extensive measuring instrumentation was built. The test results agree widely with the design values.
Design of a Heat Recovery Steam Generator
Authors: Logeais David R.
Published: April 2015

A gas turbine in the size range of 20,000 hp (14.9 MW) was retrofitted with a heat recovery steam generator (HRSG). The HRSG produces high pressure superheated steam for use in a steam turbine. Supplementary firing is used to more than double the steam production over the unfired case.

Because of many unusual constraints, an innovative design of the HRSG was formulated. These design constraints included:

1. A wide range of operating conditions was to be accommodated.

2. Very limited space in the existing plant.

3. A desire to limit the field construction work necessary in order to provide a short turn-around time.

This paper will discuss the design used to satisfy these conditions.
Application of Gas Turbine Generators for Preheating Combustion Air With Conventional Boilers or Furnaces
Authors: Davidse J. , Roukema J.
Published: April 2015

This paper will describe a co-generation system using a conventional boiler or process heater and applying a gas turbine to provide preheated combustion air to the boiler or furnace.

A number of design considerations such as applicable type and size of the gas turbine, expected energy savings and control and safety aspects are discussed. These design considerations should be taken into account when retrofitting a conventional plant into a co-generation system.

The paper will also describe such a type of co-generation system with a process heater which is in operation at the Chevron/Texaco Refinery in The Netherlands.
Use of an Inverse Method for the Design of High Efficiency Compressor and Turbine Blades With Large Change in Radius
Authors: Meauzé G. , Lesain A.
Published: April 2015

Extension of the time-marching computations of flows in 2-D blade cascades to the case of cascades with variable radius and stream tube thickness. One of the specific cases analyzed is that of purely radial cascades. Direct and inverse calculations are made, in non-viscous subsonic or supersonic flows, with or without shock waves. Examples of the design of high efficiency airfoil optimization for radial flow compressor rotors or Stators or inward flow turbine inlet guide vanes are presented.
Computation of Transonic Flows in and About Turbine Cascades With Viscous Effects
Authors: Singh U. K.
Published: April 2015

An inviscid-viscous interaction treatment has been developed to predict the flow through transonic axial turbine blade cascades. The treatment includes a trailing-edge base pressure model. This model is based on treating the area between the points of flow separation on the blade surfaces at the trailing-edge and the point of downstream confluence of the suction and pressure surface flows as a region of constant pressure. A time marching technique is used to calculate the inviscid flow and viscous flow is calculated by integral methods for laminar and turbulent boundary layers. Good agreement with experimental data has been obtained.
The Development of the RB211-24C Industrial Gas Generator to Operate on Medium Btu Gas
Authors: Willis Jeffrey D.
Published: April 2015

This paper describes a programme of work carried out to demonstrate that the RB211-24C aero derivative gas generator is able to operate satisfactorily on medium Btu gas typical of that produced from a process gas conditioning system. Rig tests were carried out to identify a combustor design capable of operating throughout the entire engine power range, i.e. ignition to full power. Finally engine tests to determine combustor and engine performance including handling and bearing loads were performed on a simulated medium Btu gas using a variable propane/nitrogen system. The results obtained demonstrate that the RB211-24C is capable of operating on a variety of gases with widely different calorific values. Also, when operating on medium Btu gas a significant improvement in specific fuel consumption and an increase in power are achieveable.
Examination of Coal and Ash Samples by PIXE Method for Gas Turbine Applications
Authors: Raj S. , Raj R. , Hall G.
Published: April 2015

A new technique, PIXE - Particle Induced X-Ray Emission, for analyzing concentration of trace elements with a detection concentration in parts per million is presented in this paper.

PIXE is performed on a sample by using a proton beam. The experimental results are obtained from a number of coal and ash samples useful for the combined cycle power plants. The technique is useful for deposit analysis and analysis of eroded and corroded surfaces. This technique can identify depth of deposit and chemical constituents simultaneously.
An Investigation of the Transverse Velocity Profile in the Case of Internal Viscous Aerodynamic Problems
Authors: Kotidis P. , Chaviaropoulos P. , Papailiou K. D.
Published: April 2015

The development of transverse velocity profile is directly related to the development of secondary vorticity. In the internal aerodynamics case with potential external flow, although vorticity remains confined inside the viscous shear layer, secondary vorticity induced velocities exist outside of it.

If the secondary vorticity field is known, the induced secondary velocity field is well approximated following Hawthorne’s classical analysis. In the present work, the above analysis is used to separate the velocity field in the transverse plane into a potential and a rotational part. In the case of confined flows, the rotational part is confined inside the viscous shear layer, while the potential part occupies the whole flow field. This last part is the consequence of the “displacement” effects of the shear layer in the transverse plane.

Therefore, the present work allows a re-examination of the flow two-zone model (separation of the flow field in a viscous and an inviscid part) in confined flows.

On the other hand, the limitations of Hawthorne’s theory are examined, while a parallel analysis is presented for the case where the secondary vorticity distribution varies not only along the blade height, but also circumferentially.
Accuracy and Convergence Characteristics of Steady Transonic Potential Flow Solutions
Authors: Ecer A. , Yurtseven H. O. , Karaca C.
Published: April 2015

This paper discusses the importance of artificial viscosity in analyzing transonic potential flows in terms of:

•convergence characteristics of a relaxation scheme, and

•accuracy of the obtained solutions.

In this first part of the paper, two types of relaxation schemes are discussed where different types of damping terms are employed. The utilization of artificial viscosity for these different procedures are studied. In the second part, the accuracy of solutions obtained by employing artificial viscosity is investigated, in particular for the solution around a shock. Finally, it is suggested that comparison of solutions with different levels of artificial viscosity may be an efficient tool in determining the accuracy of the obtained solution.
A Finite Element Computer Code to Calculate Full 3–D Compressible Potential Flow in Turbomachinery
Authors: Güneş Doğan , Mengütürk Muhsin
Published: April 2015

A Finite element computer code is presented for calculation of three-dimensional compressible flows in turbomachinery under the steady and potential flow limitations. The method used relies upon a variational statement equivalent to the classical velocity potential formulation of this problem. The solution domain is discretized by using hexahedral superelements each composed of six ten-node tetrahedral elements enabling quadratic interpolation of velocity potential. The code offers the flexibility of choosing a combination of subparametric and isoparametric elements. Application of the code to the Gostelow cascade, an experimental turbine stator, the first stage stator and rotor of an electric utility axial flow turbine and finally to a mixed flow turbine rotor are presented. The validity of the results are established by comparison with the exact solution, experimental data and calculations by other numerical methods.
A Study of the Prediction of Tip and Seal Clearances and Their Effects in Gas Turbine Transients
Authors: Pilidis P. , Maccallum N. R. L.
Published: April 2015

Clearances of compressor and turbine blade tips and seals alter during and following speed transients. These changes affect the performance of the components and hence of the engine.

This paper describes models for the prediction of blade tip clearance changes and seal clearance changes. These models have been applied to the H.P. Compressor and H.P. Turbine and to two seals controlling air flows in a Two-spool Bypass Engine. The predicted acceleration rates appear to be more influenced by the changes in the seal clearances than by the tip clearance changes.

The increases in computing time in the engine transient program which result from inclusion of the model are acceptable.
Simplified Method for Flow Analysis and Performance Calculation Through an Axial Compressor
Authors: Miton Hubert , Doumandji Youssef , Chauvin Jacques
Published: April 2015

This paper describes a fast computation method of the flow through multistage axial compressors of the industrial type. The flow is assumed to be axisymmetric between the blade rows which are represented by actuator disks. Blade row losses and turning are calculated by means of correlations.

The equations of motion are linearized with respect to the log of static pressure, whose variation along the radius is usually of limited extent for the type of machines for which the method has been developed.

In each computing plane (i.e. between the blade rows) two flows are combined: a basic flow with constant pressure satisfying the mass flow requirements and a perturbation flow fulfilling the radial equilibrium condition.

The results of a few sample calculations are given. They show a satisfactory agreement with a classical duct flow method although the computing time is reduced by a factor five.

The method has also been coupled with a surge line prediction calculation.
Very High Efficiency Small Nuclear Gas Turbine Power Plant Concept (HTGR-GT/BC) for Special Applications
Authors: McDonald C. F. , Cavallaro L. , Kapich D. , Medwid W. A.
Published: April 2015

To meet the energy needs of special terrestrial defense installations, where a premium is placed on high plant efficiency, conceptual studies have been performed on an advanced closed-cycle gas turbine system with a high-temperature gas-cooled reactor (HTGR) as the heat source. Emphasis has been placed on system compactness and plant simplicity. A goal of plant operation for extended periods with no environmental contact had a strong influence on the design features. To realize a high plant efficiency (over 50%) for this mode of operation, a combined cycle was investigated. A primary helium Brayton power conversion system coupled with a Freon bottoming cycle was selected.

The selection of a gas turbine power conversion system is very much related to applications where high efficiency is paramount and this can be realized with the utilization of a cold heat sink. Details are presented of the reactor arrangement, power conversion system, major components, installation, and performance for a compact nuclear power plant currently in a very early stage of concept definition.
The Closed Cycle Gas Turbine, the Most Efficient Turbine Burning any Fuel
Authors: Sawyer R. Tom
Published: April 2015

The are two types of gas turbines. The open cycle is very well known as for example the JET. The closed cycle in the U.S.A. is just starting to be well known. In Europe the closed cycle gas turbine has been used in power plants, especially in Germany and have been very efficient burning coal. I am going to concentrate on the CCGT - Closed Cycle Gas Turbine as it is the most efficient type of turbine. First I will give a brief report written by Dr. Curt Keller. Then the main part of this paper will give more details about the closed cycle gas turbine (CCGT) using various fuels.
Validation of Flow Coefficients Measurement by Laser Velocimeter in Straight-Through Labyrinth Seal Models With Full Size Test Rig Results
Authors: D’Emilia Giulio
Published: April 2015

In the computation of overall efficiency in turbomachines the increase of performance in high pressure centrifugal compressors renders of great importance the rôle of leakage in straight-through labyrinth seals.

A test rig for labyrinth seals used in process compressors was built in order to carry out a systematic study of the fluidodynamic phenomena characteristic of flow in these devices.

Full size seals were tested under different working conditions and the results were utilized for a quantitative definition of the experimental coefficients introduced in previsional methods which were shown the best ones on the basis of previous investigation (1).

The coefficients consider the principal fluidodynamic phenomena existent in the seals: fluid flow contraction in the throttlings and kinetic energy carry-over, which have contrasting effects on the leakage of a straight-through labyrinth seal.

The results were used to find elements of correct design in these seals. They point out besides the geometric parameters which optimize seal performance, minimizing the leakage on a fixed length of the labyrinth.

Larger scale models of the same seals tested on the above mentioned test rig were studied in a smoke tunnel under conditions which satisfied the Reynolds similarity.

This experimental set-up permitted the measurement of the velocity distributions within the straight through labyrinth seal models by means of a laser Doppler velocimeter.

Particular attention was dedicated to the definition of uncertainty of the experimental coefficients. The information obtained was satisfactory.

The results showed promising correlations between real seals and larger models. These relations could be very useful when designing labyrinth seals for centrifugal compressors, as a large part of long, costly tests on real seals could be substituted by faster and more economical measurements on models.
Technical and Economic Aspects of Closed Cycle Gas Turbines With Fluidized Bed Coal Firing
Authors: Bellofato Oreste , Galli Augusto
Published: April 2015

This paper considers the utilization of fluidized bed in various closed cycles and compares the main features of these with those of both the conventional open cycle and Rankine cycle. The possibility of developing modular closed cycle plants with 1123K max temperature is examined.
Pressurized Fluidized Bed Combustion Low Temperature Cycle Demonstration Plant
Authors: Mukherjee D. K.
Published: April 2015

The merits of the turbocharged PFBC cycle are well known. Brown Boveri have been working in the past on a concept to commercialize this technology. As the leader of a team, with Foster Wheeler, Burns & Roe and Research Cottrell, Brown Boveri have conceived a turbocharged PFBC retrofit demonstration plant (20 MWe/40 MWe, net heat rate 11,000 BTU/kWh) which is discussed below.

Several old power stations in the USA have small coal-fired electric generating units which are inactive. The boilers are usually unreliable and their overhauling is uneconomical. The balance of the systems is quite often in a relatively good condition.

In this retrofit concept the existing conventional boiler is replaced by a field-assembled PFBC steam generator with pneumatic feed system. It is considered that the steam turbogenerator with its complete condensing plant, together with the coal handling and the storage system can be used.

The estimated total construction cost for the retrofit installation amounts to $28,000,000 for the 20 MWe and to $40,200,000 for the 40 MWe plant. This price is accurate to within plus/minus 20%. An extrapolation of these costs for a 80 MWe retrofit unit using barge transport for shop-fabricated and assembled components and applying coal-water slurry feed system result in an investment cost of $600/kW approximately.

The cost of a retrofit plant looks attractive and indicates that the PFBC turbocharged cycle is economical compared to the conventional plant with FGD, as has been reported before. Improved cost prediction for a 80 MWe unit is only possible if a conceptual design is carried out.
Coal-Fueled Gas Turbine Program
Authors: Crouse F. W. , Halow J. S. , Wilson J. S.
Published: April 2015

The U.S. Department of Energy has initiated a program to stimulate the development of integrated coal-fueled gas turbine systems for generation of low-cost electric power. This paper describes the rationale and elements contained in this program. The incentives for the (DOE) coal-fueled gas turbine program are a perceived need for modular, low-cost electric generating capacity for the mid-to-late 1990’s, which will not increase the consumption of oil and the need for a low-cost option to long lead time conventional electric power generating systems. The coal-fueled gas turbine also offers the potential to repower existing electric generating facilities as well as for industrial cogeneration applications.

The primary fuels being considered are coal slurries and coal gasifier fuels under three program elements: (1) basic data studies, (2) systems and economic studies, and (3) component/system development. The basic data element is designed to address needed information on the effects of the coal and coal-derived combustion contaminants on turbine components. Basic combustion phenomena tests are being carried out by the Morgantown Energy Technology Center and by various industrial organizations to accomplish this goal. The systems and economic studies element of the program is an ongoing effort to provide program assessment and direction. Several major equipment manufacturers are parametrically examining various system configurations and fuel quality to determine process and economic implications. The component development element of the program is planned to start in 1984.

Ultimately, the success of the program will be measured by the extent of interest and willingness of the various industrial concerns to participate in the development of commercial systems. The industrial interest to date has been good, as shown by the willingness of private companies to provide cost sharing in each element of the program. This cost sharing criterion will continue as the program progresses.
Mechanical Dry Seal Applied to Pipeline (Natural Gas) Centrifugal Compressors
Authors: Hesje R. C. , Peterson R. A.
Published: April 2015

NOVA, An Alberta Corporation is a major Canadian energy company actively involved in natural gas transportation and marketing, petroleum, petrochemicals, manufacturing, consulting and research.
Experience in the Operation of Air Filters in Gas Turbine Installations
Authors: Zaba T. , Lombardi P.
Published: April 2015

Industrial gas turbines swallow air at a rate of approximately 14 to 16 kg/kWh. Even in clean environments the amount of solid particle ingestion is significant. A 70.000 kW gas turbine operating in a typical residential area could ingest 1.3 to 1.5 kg of solid contaminants in a 24 hour period. The same gas turbine operating in a typical mining or oil field region could ingest 33 to 39 kg of solid contaminants in a 24 hour period. Depending on the composition, size, quantity and condition (wet, dry, sticky) of the ingested particles, performance loss, due to the fouling of the compressor and/or turbine and hardware deterioration, due to erosion, corrosion and/or foreign object damage, can be experienced.

To protect against performance loss and hardware deterioration, industrial gas turbines are normally equipped with air inlet filtration systems. However, the effectiveness of the filtration system depends on how well it is matched to the contaminants and site conditions. Matching the filtration system to the contaminants and site conditions is usually a judgement decision based on experience and available information. This paper was written in an effort to enhance the equipment selection process by reviewing BBC’s experience with air inlet filtration systems.
A Report for the Engineering Status of Some Confirmation Tests in the Development of AGTJ-100A
Authors: Teshima Kiyomi , Ozaka Kenji , Koga Akinori , Aoki Sonao
Published: April 2015

In the course of designing the turbine of the AGTJ-100A, some technical subjects needed to be confirmed, such as design technology and precise data of cooling engineering, aerodynamic effects of discharged air flow from blades and aerodynamic characteristics of gas passage, in order to attain smooth operation of the machine, and precautional vibration tests of blades with long spans.

A series of component tests were organized to support the design engineering and to confirm parts of the design data by the Engineering Department of “Engineering Research Association for Advanced Gas Turbines” and conducted by the associate manufactures by allotment.
Special Design Considerations and Operating Experience of Two Gas Turbine Power Plants in Libya
Authors: Lau Kim Y.
Published: April 2015

This paper describes two gas turbine power plants in Libya which use multiple units of the Westinghouse W191G ECONO-PAC as turbine-generator sets. Special design considerations in the crude and residual fuel burning capability and system performance on instant electrical load pick-up are described in detail. The field test results of the turbine control system are also summarized in this paper. In addition, some of the operating experience in the fuel system and gas turbine combustion system is discussed briefly.
A Contribution to the Study of the Design of an Industrial Centrifugal Compressor
Authors: Papailiou K. D. , Bois G.
Published: April 2015

The present work has had as a starting point an already existing high hub/tip ratio industrial centrifugal compressor design. An effort was undertaken to design a first new machine using theoretical methods, keeping, however, the overall geometrical dimensions, issued from the experience of the industry. The new design was manufactured and tested. The test results were found to be rather good, compared with the current industrial experience.

Additionally, a second new design was undertaken which had as aim to diminish the axial part length, leaving untouched the hub/tip ratio. If this effort was successful, it would mean that the length of the shaft for a multistage arrangement could be diminished and, thus the need for such a high hub/tip ratio, resulting from the shaft diameter. It was found, actually, possible to reduced the axial length of the inducer by a factor of two, approximately. The second new design was manufactured and the resulting machine, when tested, was found to have the same performances as the first new design.

A rather interesting point of the whole design procedure was the fact that a boundary layer calculation method was used in the blade-to-blade surface, which could take into account the influence of the Coriolis force and blade curvature on turbulence.

The impact of this influence on the whole design was found to be decisive.

The calculation procedure, the two designs and the overall test rests are described in the present work.
Development of the PGT 25 High Efficiency Gas Turbine: Part 1 — Outline of Machine Layout and Auxiliaries
Authors: Gusso R. , Mezzedimi V.
Published: April 2015

This paper outlines the main features of the PGT 25 turbine and its auxiliares. The machine utilizes aero-derivative gas generators and has been primarily designed for mechanical drive applications; the prototype turbine and the first nine production units have been sized for matching with the LM 2500/30 gas generator, for a nominal shaft power between 21,300 KW and 22,100 KW.

The design shaft speed of 6,500 RPM has been selected for optimum matching of pipeline booster compressors for the range of powers of the PGT 25 turbine family.

The machine has been designed as a system of preassembled, shop tested modules to make transportation and installation as easy as possible.

Maintenance requirements have been given particular attention to provide the highest degree of availability.
Further Data on the Performance of a Rectangular Diffuser in Distorted Inlet Flows
Authors: Bhinder F. S. , Al-Mudhafar M. M. , Ilyas M.
Published: April 2015

A low aspect ratio plane wall diffuser has been tested for a variety of inlet velocity profiles and range of mean inlet Mach numbers. The inlet distortion parameter, which defines the velocity profiles quantitatively, correlates well with the performance parameters such as pressure recovery coefficient, effectiveness and diffusion efficiency. The empirical expressions for these correlations have been derived.
Analysis of Time Marching Numerical Methods and Boundary Conditions for Turbomachinery Flow Computation
Authors: Subramanian S. V.
Published: April 2015

The unsteady Euler equations are numerically solved using the finite volume integration method to obtain steady solutions. The one step Lax-Wendroff and the unsplit version of MacCormack schemes are used for the finite difference approximation. Both these methods are second order accurate in space and time, fully explicit and are applied to the governing equations in the conservation law form. The accuracy and computational efficiency of the present schemes are examined under physically realistic cascade flow conditions. The model problems considered for this purpose include a two-dimensional supersonic nozzle, a transonic compressor cascade and turbine geometries with subcritical and supercritical flow conditions. The influence of boundary condition treatment, flow geometry variation and artificial smoothing method on the resultant solution are also studied. Computed results are compared with test data and other numerical methods for illustrative purpose.
Design Objectives and Experience With Processor Based Gas Turbine Controls
Authors: Lenz Hans D.
Published: April 2015

This paper describes the control system requirements to reduce operating costs of gas turbine driven equipment, and the features and technologies available from up-to-date control systems to meet these requirements.

Modern control systems can affect the cost of operation in the following areas:

- Reduction of downtime.

- Optimizing of performance during all operating conditions.

- Long-term trending and failure diagnostics to maintain optimum efficiency and for preventive maintenance.

Advances in electronic technology, especially microprocessors, make it possible to achieve improvements in these areas. Programming methods, an important tool in the application of this technology, are discussed.

Applications of control systems are used to illustrate their effectiveness. Guidelines are presented to judge the value of different types of control systems in gas turbine and other applications and a look at future developments is presented.
Stress Mapping of a Low Pressure Compressor for an Advanced Turbojet Engine
Authors: Bankhead H. R. , Meece C. E.
Published: April 2015

Vibratory stress characteristics of the low pressure compressor in the Pratt & Whitney Aircraft PW1120 turbojet engine recently have been evaluated during full-scale engine testing at the United States Air Force’s Arnold Engineering Development Center. A description is presented of the approach used to evaluate the vibratory characteristics of the new three stage low pressure compressor. Results are presented showing the effects of simulated altitude conditions, inlet pressure distortion, and off-schedule variable vane operation. Strain gage data is compared to case-mounted light probe data, and the levels of system damping and mistuning are discussed. Predicted vibratory response is compared to test results showing the new compressor to be free of destructive vibration.
Use of B2O3 films grown by plasma-assisted atomic layer deposition for shallow boron doping in silicon
Authors: Kalkofen Bodo , Amusan Akinwumi A. , Bukhari Muhammad S. K. , Garke Bernd , Lisker Marco , Gargouri Hassan , Burte Edmund P.
Published: April 2015

Plasma-assisted atomic layer deposition (PALD) was carried for growing thin boron oxide films onto silicon aiming at the formation of dopant sources for shallow boron doping of silicon by rapid thermal annealing (RTA). A remote capacitively coupled plasma source powered by GaN microwave oscillators was used for generating oxygen plasma in the PALD process with tris(dimethylamido)borane as boron containing precursor. ALD type growth was obtained; growth per cycle was highest with 0.13 nm at room temperature and decreased with higher temperature. The as-deposited films were highly unstable in ambient air and could be protected by capping with in-situ PALD grown antimony oxide films. After 16 weeks of storage in air, degradation of the film stack was observed in an electron microscope. The instability of the boron oxide, caused by moisture uptake, suggests the application of this film for testing moisture barrier properties of capping materials particularly for those grown by ALD. Boron doping of silicon was demonstrated using the uncapped PALD B2O3 films for RTA processes without exposing them to air. The boron concentration in the silicon could be varied depending on the source layer thickness for very thin films, which favors the application of ALD for semiconductor doping processes.
Singled out: Profiling metabolic and proteomic heterogeneity
Authors: Wong Ian Y.
Published: April 2015

A microfluidic assay enables multiplexed single-cell analysis of metabolites and proteins in glioblastoma cells.
Acute fatty liver of pregnancy with hypoglycaemia, diabetes insipidus and pancreatitis, preceded by intrahepatic cholestasis of pregnancy
Authors: English Nicola , Rao Jegajeeva
Published: April 2015

We present the case of a 33-year-old woman in her first pregnancy. She presented with pruritus at 34 weeks gestation. A diagnosis of intrahepatic cholestasis of pregnancy was made based on elevated bile acids and elevated liver transaminases. She re-presented 4 days later, jaundiced with abdominal pain and nausea, and was hypertensive. Her bilirubin was now elevated and her creatinine had doubled. The differential diagnosis-included pre-eclampsia and Hemolysis Elevated Liver enzymes Low Platelet count (HELLP) syndrome, and delivery was expedited. Postnatally, the patient became coagulopathic, though not thrombocytopaenic; she had persistent hypoglycaemia, hyponatraemia, developed acute pancreatitis and had profound ascites and peripheral oedema. Management was supportive with multidisciplinary care and over a period of 3 weeks she made a full clinical and biochemical recovery.