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1

The application of hydraulics in the 2,000 kW wind turbine generator  

NASA Technical Reports Server (NTRS)

A 2000 kW turbine generator using hydraulic power in two of its control systems is being built under the management of NASA Lewis Research Center. The hydraulic systems providing the control torques and forces for the yaw and blade pitch control systems are discussed. The yaw-drive-system hydraulic supply provides the power for positioning the nacelle so that the rotary axis is kept in line with the direction of the prevailing wind, as well as pressure to the yaw and high speed shaft brakes. The pitch-change-mechanism hydraulic system provides the actuation to the pitch change mechanism and permits feathering of the blades during an emergency situation. It operates in conjunction with the overall windmill computer system, with the feather control permitting slewing control flow to pass from the servo valve to the actuators without restriction.

Onufreiczuk, S.

1978-01-01

2

Development of the water-lubricated thrust bearing of the hydraulic turbine generator  

NASA Astrophysics Data System (ADS)

In hydropower plant, a large quantities of turbine oil is used as machine control pressure oil and lubricating oil. If the oil leak out from hydropower plant, it flows into a river. And such oil spill has an adverse effect on natural environment because the oil does not degrade easily. Therefore the KANSAI and Hitachi Mitsubishi Hydro developed the water-lubricated thrust bearing for vertical type hydraulic turbine generator. The water-lubricated bearing has advantages in risk avoidance of river pollution because it does not need oil. For proceeding the development of the water-lubricated thrust bearing, we studied following items. The first is the examination of the trial products of water lubricating liquid. The second is the study of bearing structure which can satisfy bearing performance such as temperature characteristic and so on. The third is the mock-up testing for actual application in the future. As a result, it was found that the water-lubricated thrust bearing was technically applicable to actual equipments.

Inoue, K.; Deguchi, K.; Okude, K.; Fujimoto, R.

2012-11-01

3

Maintaining electro-hydraulic-control (EHC) systems for turbine generators using phosphate ester EHC fluid  

Microsoft Academic Search

The requirements for maintaining an electrohydraulic control system through proper care of the phosphate ester fluid are described. Phosphate ester fluids are used on EHC turbine generator controls for their fire resistant characteristics that reduce the risk of fires if a leak were to occur. Some of the key elements in maintaining the fluid are shown to be cleanliness by

R. Crane

1992-01-01

4

Downhole hydraulic seismic generator  

DOEpatents

A downhole hydraulic seismic generator system for transmitting energy wave vibrations into earth strata surrounding a borehole. The system contains an elongated, unitary housing operably connected to a well head aboveground by support and electrical cabling, and contains clamping apparatus for selectively clamping the housing to the walls of the borehole. The system further comprises a hydraulic oscillator containing a double-actuating piston whose movement is controlled by an electro-servovalve regulating a high pressure hydraulic fluid flow into and out of upper and lower chambers surrounding the piston. The spent hydraulic fluid from the hydraulic oscillator is stored and pumped back into the system to provide high pressure fluid for conducting another run at the same, or a different location within the borehole.

Gregory, Danny L. (Corrales, NM); Hardee, Harry C. (Albuquerque, NM); Smallwood, David O. (Albuquerque, NM)

1992-01-01

5

Development of a hydraulic turbine design method  

NASA Astrophysics Data System (ADS)

In this paper a hydraulic turbine parametric design method is presented which is based on the combination of traditional methods and parametric surface modeling techniques. The blade of the turbine runner is described using Bezier surfaces for the definition of the meridional plane as well as the blade angle distribution, and a thickness distribution applied normal to the mean blade surface. In this way, it is possible to define parametrically the whole runner using a relatively small number of design parameters, compared to conventional methods. The above definition is then combined with a commercial CFD software and a stochastic optimization algorithm towards the development of an automated design optimization procedure. The process is demonstrated with the design of a Francis turbine runner.

Kassanos, Ioannis; Anagnostopoulos, John; Papantonis, Dimitris

2013-10-01

6

Turbine hydraulic assessment and optimization in rehabilitation projects  

NASA Astrophysics Data System (ADS)

As turbines age after years of operation, a major rehabilitation is needed to give new life. The owner has two choices: resetting the turbine to the original state or an upgrade with new hydraulic components designed and optimized using state of the art technology. The second solution is by far a more interesting option which can maximize the efficiency gain, increase the turbine capacity and revenues, eliminate cavitation erosion and the needs for repair, reduce the turbine instabilities and smooth unit regulation, and adapt the design to new operation conditions. This paper shows some aspects of the turbine hydraulic assessment and possible solutions to improve existing water passages.

Bornard, L.; Debeissat, F.; Labrecque, Y.; Sabourin, M.; Tomas, L.

2014-12-01

7

Control apparatus for hydraulically driven generator  

SciTech Connect

Apparatus for controlling a hydraulically driven generator for supplying electrical power to power mains. The generator is coupled to a turbine driven by a fluid flow through a duct. The duct has a one-fourth turn butterfly valve controlled by a fluid-actuated operator and the operator receives fluid from the duct by way of a normally closed valve which, when energized, creates water pressure on the operator for opening the butterfly valve. A second, normally open solenoid provides an emergency exit for the water from the operator to relieve the water pressure thereon and thereby close the butterfly valve when certain conditions exist, such as sudden loss of line voltage, overvoltage or deviation in frequency of the line voltage. A differential pressure switch across the turbine rotor also controls the starting of the system to assure proper flow of fluid through the duct before commencing operation of the generator itself.

Beckwith, S.

1985-08-06

8

Research of performance prediction to energy on hydraulic turbine  

NASA Astrophysics Data System (ADS)

Refer to the low specific speed Francis turbine blade design principle and double-suction pump structure. Then, design a horizontal double-channel hydraulic turbine Francis. Through adding different guide vane airfoil and and no guide vane airfoil on the hydraulic conductivity components to predict hydraulic turbine energy and using Fluent software to numerical simulation that the operating conditions and point. The results show that the blade pressure surface and suction surface pressure is low when the hydraulic turbine installation is added standard positive curvature of the guide vane and modified positive curvature of guide vane. Therefore, the efficiency of energy recovery is low. However, the pressure of negative curvature guide vane and symmetric guide vane added on hydraulic turbine installations is larger than that of the former ones, and it is conducive to working of runner. With the decreasing of guide vane opening, increasing of inlet angle, flow state gets significantly worse. Then, others obvious phenomena are that the reflux and horizontal flow appeared in blade pressure surface. At the same time, the vortex was formed in Leaf Road, leading to the loss of energy. Through analyzing the distribution of pressure, velocity, flow lines of over-current flow in the the back hydraulic conductivity components in above programs we can known that the hydraulic turbine installation added guide vane is more reasonable than without guide vanes, it is conducive to improve efficiency of energy conversion.

Quan, H.; Li, R. N.; Li, Q. F.; Han, W.; Su, Q. M.

2012-11-01

9

Detection of cavitation vortex in hydraulic turbines using acoustic techniques  

NASA Astrophysics Data System (ADS)

Cavitation phenomena are known for their destructive capacity in hydraulic machineries and are caused by the pressure decrease followed by an implosion when the cavitation bubbles find an adverse pressure gradient. A helical vortex appears in the turbine diffuser cone at partial flow rate operation and can be cavitating in its core. Cavity volumes and vortex frequencies vary with the under-pressure level. If the vortex frequency comes close to one of the eigen frequencies of the turbine, a resonance phenomenon may occur, the unsteady fluctuations can be amplified and lead to important turbine and hydraulic circuit damage. Conventional cavitation vortex detection techniques are based on passive devices (pressure sensors or accelerometers). Limited sensor bandwidths and low frequency response limit the vortex detection and characterization information provided by the passive techniques. In order to go beyond these techniques and develop a new active one that will remove these drawbacks, previous work in the field has shown that techniques based on acoustic signals using adapted signal content to a particular hydraulic situation, can be more robust and accurate. The cavitation vortex effects in the water flow profile downstream hydraulic turbines runner are responsible for signal content modifications. Basic signal techniques use narrow band signals traveling inside the flow from an emitting transducer to a receiving one (active sensors). Emissions of wide band signals in the flow during the apparition and development of the vortex embeds changes in the received signals. Signal processing methods are used to estimate the cavitation apparition and evolution. Tests done in a reduced scale facility showed that due to the increasing flow rate, the signal -- vortex interaction is seen as modifications on the received signal's high order statistics and bandwidth. Wide band acoustic transducers have a higher dynamic range over mechanical elements; the system's reaction time is reduced, resulting in a faster detection of the unwanted effects. The paper will present an example of this new investigation technique on a vortex generator in the test facility that belongs to ICPE- CA.

Candel, I.; Bunea, F.; Dunca, G.; Bucur, D. M.; Ioana, C.; Reeb, B.; Ciocan, G. D.

2014-12-01

10

NEXT GENERATION TURBINE PROGRAM  

SciTech Connect

The Next Generation Turbine (NGT) Program's technological development focused on a study of the feasibility of turbine systems greater than 30 MW that offer improvement over the 1999 state-of-the-art systems. This program targeted goals of 50 percent turndown ratios, 15 percent reduction in generation cost/kW hour, improved service life, reduced emissions, 400 starts/year with 10 minutes to full load, and multiple fuel usage. Improvement in reliability, availability, and maintainability (RAM), while reducing operations, maintenance, and capital costs by 15 percent, was pursued. This program builds on the extensive low emissions stationary gas turbine work being carried out by Pratt & Whitney (P&W) for P&W Power Systems (PWPS), which is a company under the auspices of the United Technologies Corporation (UTC). This study was part of the overall Department of Energy (DOE) NGT Program that extends out to the year 2008. A follow-on plan for further full-scale component hardware testing is conceptualized for years 2002 through 2008 to insure a smooth and efficient transition to the marketplace for advanced turbine design and cycle technology. This program teamed the National Energy Technology Laboratory (NETL), P&W, United Technologies Research Center (UTRC), kraftWork Systems Inc., a subcontractor on-site at UTRC, and Multiphase Power and Processing Technologies (MPPT), an off-site subcontractor. Under the auspices of the NGT Program, a series of analyses were performed to identify the NGT engine system's ability to serve multiple uses. The majority were in conjunction with a coal-fired plant, or used coal as the system fuel. Identified also was the ability of the NGT system to serve as the basis of an advanced performance cycle: the humid air turbine (HAT) cycle. The HAT cycle is also used with coal gasification in an integrated cycle HAT (IGHAT). The NGT systems identified were: (1) Feedwater heating retrofit to an existing coal-fired steam plant, which could supply both heat and peaking power (Block 2 engine); (2) Repowering of an older coal-fired plant (Block 2 engine); (3) Gas-fired HAT cycle (Block 1 and 2 engines); (4) Integrated gasification HAT (Block 1 and 2 engines). Also under Phase I of the NGT Program, a conceptual design of the combustion system has been completed. An integrated approach to cycle optimization for improved combustor turndown capability has been employed. The configuration selected has the potential for achieving single digit NO{sub x}/CO emissions between 40 percent and 100 percent load conditions. A technology maturation plan for the combustion system has been proposed. Also, as a result of Phase I, ceramic vane technology will be incorporated into NGT designs and will require less cooling flow than conventional metallic vanes, thereby improving engine efficiency. A common 50 Hz and 60 Hz power turbine was selected due to the cost savings from eliminating a gearbox. A list of ceramic vane technologies has been identified for which the funding comes from DOE, NASA, the U.S. Air Force, and P&W.

William H. Day

2002-05-03

11

Large wind turbine generators  

NASA Technical Reports Server (NTRS)

The development associated with large wind turbine systems is briefly described. The scope of this activity includes the development of several large wind turbines ranging in size from 100 kW to several megawatt levels. A description of the wind turbine systems, their programmatic status and a summary of their potential costs is included.

Thomas, R. L.; Donovon, R. M.

1978-01-01

12

Anticipatory control of turbine generators  

E-print Network

: Electrical Engineering ANTICIPATORY CONTROL OF TURBINE GENERATORS A Thesis By FREDDIE LAUREL MESSEC Approved as to style and content by: airman o Cosmist e ( yj~ Hea o, epartm / Member em r Member May 1971 ABSTRACT Anticipatory Control.... 55 Appendix Figure A-1 Block diagram of the discrete time solution of (A-l). 65 INTRODUCTION Steam turbine generators account for approximately four-fifths of the total electric generation in the United States [1]. The electric energy delivered...

Messec, Freddie Laurel

2012-06-07

13

Effective Lightning Protection For Wind Turbine Generators  

Microsoft Academic Search

A wind turbine generator is the most exposed of all types of generators connected to electric utility systems. Wind turbines are most often erected in hostile lightning environments. Lightning damage to wind turbines is costly in terms of repair and replacement of equipment. Lightning damage is the single largest cause of unplanned downtime in wind turbines, and that downtime is

Bruce Glushakow

2007-01-01

14

CFD configurations for hydraulic turbine startup  

NASA Astrophysics Data System (ADS)

This paper presents various numerical setups for modelling Francis turbine startups involving moving meshes and variable runner speed in order to help define best practices. During the accelerating phase of the startup, the flow is self-similar between channels, thus making single sector configuration appropriate. Adding the draft tube improves the results by allowing pressure recovery midway during in the startup. At the speed no-load regime, a rotating stall phenomenon occurs and can only be capted with the full runner included in the simulation. Comparison with experimental data, such as runner speed and strain gauge measurements, generally shows good agreement.

Nicolle, J.; Giroux, A. M.; Morissette, J. F.

2014-12-01

15

Effects of turbine's selection on hydraulic transients in the long pressurized water conveyance system  

NASA Astrophysics Data System (ADS)

For a hydropower station with longer water conveyance system, an optimum turbine's selection will be beneficial to its reliable and stable operation. Different optional turbines will result in possible differences of the hydraulic characteristics in the hydromechanical system, and have different effects on the hydraulic transients' analysis and control. Therefore, the premise for turbine's selection is to fully understand the properties of the optional turbines and their effects on the hydraulic transients. After a brief introduction of the simulation models for hydraulic transients' computation and stability analysis, the effects of hydraulic turbine's characteristics at different operating points on the hydro-mechanical system's free vibration analysis were theoretically investigated with the hydraulic impedance analysis of the hydraulic turbine. For a hydropower station with long water conveyance system, based on the detailed hydraulic transients' computation respectively for two different optional turbines, the effects of the turbine's selection on hydraulic transients were analyzed. Furthermore, considering different operating conditions for each turbine and the similar operating conditions for these two turbines, free vibration analysis was comprehensively carried out to reveal the effects of turbine's impedance on system's vibration characteristics. The results indicate that, respectively with two different turbines, most of the controlling parameters under the worst cases have marginal difference, and few shows obvious differences; the turbine's impedances under different operating conditions have less effect on the natural angular frequencies; different turbine's characteristics and different operating points have obvious effects on system's vibration stability; for the similar operating conditions of these two turbines, system's vibration characteristics are basically consistent with each other.

Zhou, J. X.; Hu, M.; Cai, F. L.; Huang, X. T.

2014-12-01

16

Numerical prediction of erosion on guide vanes and in labyrinth seals in hydraulic turbines  

Microsoft Academic Search

Erosion in hydraulic power plants is caused by sand particles in the flow. This is one of the major problems that restricts the lifetime between overhauls of water turbines. Especially those parts of the hydraulic turbine which are exposed to high flow velocities bear a considerable risk of being damaged by erosion processes. Therefore, suitable methods for the prediction of

Reiner Mack; Peter Drtina; Egon Lang

1999-01-01

17

Microprocessor control of a wind turbine generator  

NASA Technical Reports Server (NTRS)

A microprocessor based system was used to control the unattended operation of a wind turbine generator. The turbine and its microcomputer system are fully described with special emphasis on the wide variety of tasks performed by the microprocessor for the safe and efficient operation of the turbine. The flexibility, cost and reliability of the microprocessor were major factors in its selection.

Gnecco, A. J.; Whitehead, G. T.

1978-01-01

18

Biomass gasifier gas turbine power generating technology  

Microsoft Academic Search

Integrating gasifiers with gas turbines, aeroderivative gas turbines in particular, makes it possible to achieve high efficiencies and low unit capital costs in modest-scale biomass power generating facilities. Electricity produced with biomass-integrated gasifier\\/gas turbine (BIG\\/GT) power systems would be competitive with electricity produced from coal and nuclear energy under a wide range of circumstances. Biomass also offers major environmental benefits.

R. H. Williams; E. D. Larson

1996-01-01

19

An evaluation of a hubless inducer and a full flow hydraulic turbine driven inducer boost pump  

NASA Technical Reports Server (NTRS)

The purpose of the study was to compare the performance of several configurations of hubless inducers with a hydrodynamically similar conventional inducer and to demonstrate the performance of a full flow hydraulic turbine driven inducer boost pump using these inducers. A boost pump of this type consists of an inducer connected to a hydraulic turbine with a high speed rotor located in between. All the flow passes through the inducer, rotor, and hydraulic turbine, then into the main pump. The rotor, which is attached to the main pump shaft, provides the input power to drive the hydraulic turbine which, in turn, drives the inducer. The inducer, rotating at a lower speed, develops the necessary head to prevent rotor cavitation. The rotor speed is consistent with present main engine liquid hydrogen pump designs and the overall boost pump head rise is sufficient to provide adequate main pump suction head. This system would have the potential for operating at lower liquid hydrogen tank pressures.

Lindley, B. K.; Martinson, A. R.

1971-01-01

20

Challenges in Dynamic Pressure and Stress Predictions at No-Load Operation in Hydraulic Turbines  

NASA Astrophysics Data System (ADS)

Some of the potentially most damaging continuous operating conditions for hydraulic turbines are the no-load (NL) conditions. At NL conditions the flow passes through the turbine without power generation, but with non-negligible flow rate, and therefore all the potential energy in the flow has to be dissipated. This takes place through a mechanism where the runner channels are partially pumping, thus generating large scale unsteady vortex structures which, by their nature, break down into smaller and smaller vortices until energy dissipation occurs at the smallest scales. This type of flow, dominated by its turbulent character, is inherently difficult to simulate by means of numerical methods since turbulence model and numerical dissipation have a major influence. The resulting dynamic loads on the runner are largely of stochastic nature, exciting a broad band of frequencies and thus, almost always interact with at least one deformation mode. The presented investigations are aimed at predicting the effect of the unsteady NL pressure loads on the fatigue life of a Francis turbine runner. A combination of computational fluid dynamics (CFD) and finite element analysis (FEA) methods has been employed. The results from transient CFD simulations are presented. Comparison of the results with prototype strain gauge measurements at no load conditions shows that the stochastic nature and the approximate range of the dynamic stresses can be predicted.

Nennemann, B.; Morissette, J. F.; Chamberland-Lauzon, J.; Monette, C.; Braun, O.; Melot, M.; Coutu, A.; Nicolle, J.; Giroux, A. M.

2014-12-01

21

Experimental Study on Abrasive Waterjet Polishing of Hydraulic Turbine Blades  

NASA Astrophysics Data System (ADS)

In this paper, an experimental investigation is implemented on the abrasive waterjet polishing technique to evaluate its capability in polishing of surfaces and edges of hydraulic turbine blades. For this, the properties of this method are studied and the main parameters affecting its performance are determined. Then, an experimental test-rig is designed, manufactured and tested to be used in this study. This test-rig can be used to polish linear and planar areas on the surface of the desired workpieces. Considering the number of parameters and their levels, the Taguchi method is used to design the preliminary experiments. All experiments are then implemented according to the Taguchi L18 orthogonal array. The signal-to-noise ratios obtained from the results of these experiments are used to determine the importance of the controlled polishing parameters on the final quality of the polished surface. The evaluations on these ratios reveal that the nozzle angle and the nozzle diameter have the most important impact on the results. The outcomes of these experiments can be used as a basis to design a more precise set of experiments in which the optimal values of each parameter can be estimated.

Khakpour, H.; Birglenl, L.; Tahan, A.; Paquet, F.

2014-12-01

22

Hydraulic development of high specific-speed pump-turbines by means of an inverse design method, numerical flow-simulation (CFD) and model testing  

NASA Astrophysics Data System (ADS)

In recent years an increased interest in pump-turbines has been recognized in the market. The rapid availability of pumped storage schemes and the benefits to the power system by peak lopping, providing reserve and rapid response for frequency control are becoming of growing advantage. In that context it is requested to develop pump-turbines that reliably stand dynamic operation modes, fast changes of the discharge rate by adjusting the variable diffuser vanes as well as fast changes from pump to turbine operation. Within the present study various flow patterns linked to the operation of a pump-turbine system are discussed. In that context pump and turbine mode are presented separately and different load cases at both operation modes are shown. In order to achieve modern, competitive pump-turbine designs it is further explained which design challenges should be considered during the geometry definition of a pump-turbine impeller. Within the present study a runner-blade profile for a low head pump-turbine has been developed. For the initial hydraulic runner-blade design, an inverse design method has been applied. Within this design procedure, a first blade geometry is generated by imposing the pressure loading-distribution and by means of an inverse 3D potential-flow-solution. The hydraulic behavior of both, pump-mode and turbine-mode is then evaluated by solving the full 3D Navier-Stokes equations in combination with a robust turbulence model. Based on this initial design the blade profile has been further optimized and redesigned considering various hydraulic pump-turbine requirements. Finally, the progress in hydraulic design is demonstrated by model test results which show a significant improvement in hydraulic performance compared to an existing reference design.

Kerschberger, P.; Gehrer, A.

2010-08-01

23

NEXT GENERATION GAS TURBINE SYSTEMS STUDY  

SciTech Connect

Under sponsorship of the U.S. Department of Energy's National Energy Technology Laboratory, Siemens Westinghouse Power Corporation has conducted a study of Next Generation Gas Turbine Systems that embraces the goals of the DOE's High Efficiency Engines and Turbines and Vision 21 programs. The Siemens Westinghouse Next Generation Gas Turbine (NGGT) Systems program was a 24-month study looking at the feasibility of a NGGT for the emerging deregulated distributed generation market. Initial efforts focused on a modular gas turbine using an innovative blend of proven technologies from the Siemens Westinghouse W501 series of gas turbines and new enabling technologies to serve a wide variety of applications. The flexibility to serve both 50-Hz and 60-Hz applications, use a wide range of fuels and be configured for peaking, intermediate and base load duty cycles was the ultimate goal. As the study progressed the emphasis shifted from a flexible gas turbine system of a specific size to a broader gas turbine technology focus. This shift in direction allowed for greater placement of technology among both the existing fleet and new engine designs, regardless of size, and will ultimately provide for greater public benefit. This report describes the study efforts and provides the resultant conclusions and recommendations for future technology development in collaboration with the DOE.

Benjamin C. Wiant; Ihor S. Diakunchak; Dennis A. Horazak; Harry T. Morehead

2003-03-01

24

Installation of electric generators on turbine engines  

NASA Technical Reports Server (NTRS)

The installation of generators on turbine aircraft is discussed. Emphasis is placed on the use of the samarium cobalt generator. Potential advantages of an electric secondary power system at the engine level are listed. The integrated generator and the externally mounted generator are discussed. It is concluded that the integrated generator is best used in turbojet and low bypass ratio engines where there is no easy way of placing generators externally without influencing frontal areas.

Demel, H. F.

1983-01-01

25

Wind tunnel experiments to prove a hydraulic passive torque control concept for variable speed wind turbines  

NASA Astrophysics Data System (ADS)

In this paper the results are presented of experiments to prove an innovative concept for passive torque control of variable speed wind turbines using fluid power technology. It is demonstrated that by correctly configuring the hydraulic drive train, the wind turbine rotor operates at or near maximum aerodynamic efficiency for below rated wind speeds. The experiments with a small horizontal-axis wind turbine rotor, coupled to a hydraulic circuit, were conducted at the Open Jet Facility of the Delft University of Technology. In theory, the placement of a nozzle at the end of the hydraulic circuit causes the pressure and hence the rotor torque to increase quadratically with flow speed and hence rotation speed. The rotor torque is limited by a pressure relief valve. Results from the experiments proved the functionality of this passive speed control concept. By selecting the correct nozzle outlet area the rotor operates at or near the optimum tip speed ratio.

Diepeveen, N. F. B.; Jarquin-Laguna, A.

2014-12-01

26

Variable speed generator technology options for wind turbine generators  

NASA Technical Reports Server (NTRS)

The electrical system options for variable speed operation of a wind turbine generator are treated in this paper. The key operating characteristics of each system are discussed and the major advantages and disadvantages of each are identified

Lipo, T. A.

1995-01-01

27

Low frequency noise from MW wind turbines --mechanisms of generation  

E-print Network

Low frequency noise from MW wind turbines -- mechanisms of generation and its modeling Helge MW wind turbines -- mechanisms of generation and its modeling Department: Department of Wind Energy on this turbine a number of important turbine design parameters with influence on the LFN have been identified

28

Generating Resources Combined Cycle Combustion Turbine  

E-print Network

in efficiency and cost. Strong US focus on solar power; rapidly growing power source in California11/17/2014 1 Generating Resources Combined Cycle Combustion Turbine Utility Scale Solar PV Steven (CCCT) 2. Utility Scale Solar Photovoltaic (Solar PV) This includes cost and performanceThis includes

29

Numerical Simulations of Vortex Shedding in Hydraulic Turbines  

NASA Technical Reports Server (NTRS)

Turbomachines for rocket propulsion applications operate with many different working fluids and flow conditions. Oxidizer boost turbines often operate in liquid oxygen, resulting in an incompressible flow field. Vortex shedding from airfoils in this flow environment can have adverse effects on both turbine performance and durability. In this study the effects of vortex shedding in a low-pressure oxidizer turbine are investigated. Benchmark results are also presented for vortex shedding behind a circular cylinder. The predicted results are compared with available experimental data.

Dorney, Daniel; Marcu, Bogdan

2004-01-01

30

Infrasound emission generated by wind turbines  

NASA Astrophysics Data System (ADS)

Aerodynamic noise emissions from the continuously growing number of wind turbines in Germany are creating increasing problems for infrasound recording systems. Such systems are equipped with highly sensitive micro pressure sensors, which are accurately measuring acoustic signals in a frequency range inaudible to humans. At infrasound station IGADE, north of Bremen, a constantly increasing background noise has been observed throughout the years since its installation in 2005. The spectral peaks are reflecting well the blade passing harmonics, which vary with prevailing wind speeds. Overall, a decrease is noted for the infrasound array's detection capability. This aspect is particularly important for the other two sites of the German infrasound stations I26DE in the Bavarian Forest and I27DE in Antarctica, because plans for installing wind turbines near these locations are being under discussion. These stations are part of the International Monitoring System (IMS) verifying compliance with the Comprehensive Nuclear-Test-Ban Treaty (CTBT), and have to meet stringent specifications with respect to infrasonic background noise. Therefore data obtained during a field experiment with mobile micro-barometer stations for measuring the infrasonic pressure level of a single horizontal-axis wind turbine have been revisited. The results of this experiment successfully validate a theoretical model which estimates the generated sound pressure level of wind turbines and makes it possible to specify the minimum allowable distance between wind turbines and infrasound stations for undisturbed recording. Since the theoretical model also takes wind turbine design parameters into account, suitable locations for planned infrasound stations outside the determined disturbance range can be found, which will be presented; and vice versa, the model calculations' results for fixing the minimum distance for wind turbines planned for installation in the vicinity of an existing infrasound array.

Ceranna, Lars; Pilger, Christoph

2014-05-01

31

Experiences with the hydraulic design of the high specific speed Francis turbine  

NASA Astrophysics Data System (ADS)

The high specific speed Francis turbine is still suitable alternative for refurbishment of older hydro power plants with lower heads and worse cavitation conditions. In the paper the design process of such kind of turbine together with the results comparison of homological model tests performed in hydraulic laboratory of ?KD Blansko Engineering is introduced. The turbine runner was designed using the optimization algorithm and considering the high specific speed hydraulic profile. It means that hydraulic profiles of the spiral case, the distributor and the draft tube were used from a Kaplan turbine. The optimization was done as the automatic cycle and was based on a simplex optimization method as well as on a genetic algorithm. The number of blades is shown as the parameter which changes the resulting specific speed of the turbine between ns=425 to 455 together with the cavitation characteristics. Minimizing of cavitation on the blade surface as well as on the inlet edge of the runner blade was taken into account during the design process. The results of CFD analyses as well as the model tests are mentioned in the paper.

Obrovsky, J.; Zouhar, J.

2014-12-01

32

A Dynamic Wind Turbine Simulator of the Wind Turbine Generator System  

Microsoft Academic Search

To study dynamic performances of wind turbine generator system (WTGS), and to determine the control structures in laboratory. The dynamic torque generated by wind turbine (WT) must be simulated. In there paper, a dynamic wind turbine emulator (WTE) is designed, which consider wind shear and tower shadow effect, and a dynamic torque compensation scheme is also developed to compensate the

Lei Lu; Zhen Xie; Xing Zhang; Shuying Yang; Renxian Cao

2012-01-01

33

Flow Characteristics in an Augmentation Channel of a Direct Drive Turbine for Wave Power Generation  

Microsoft Academic Search

Cross flow turbine also known as Banki turbine, is a hydraulic turbine that may be classified as an impulse turbine. At present it has gained interest in small and low head establishments because of its simple structure, cost effectiveness and low maintenance. Therefore, the present paper expands on this idea and aims at implementing the Direct Drive Turbine (DDT) for

Deepak Prasad; Mohammed Asid Zullah; Young-Do Choi; Young-Ho Lee

2010-01-01

34

CFD Analysis for the Performance of Cross-Flow Hydraulic Turbine with the Variation of Blade Angle  

NASA Astrophysics Data System (ADS)

The purpose of this study is both to further optimize the structure of cross-flow turbine and to improve the turbine performance. Optimization of the turbine structure has been made by the analysis of the turbine performance with the variation of the blade angle using a commercial CFD code. The results show that inlet and outlet angles of the runner blade give considerable effect on the performance of the turbine. Pressure on the surface of the runner blade changes considerably with the variation of blade angle both at the stages 1 and 2 but relatively small change occurs for the fluid velocity of cross-flow hydraulic turbine. Recirculating flow in the runner passage causes considerable hydraulic loss by which efficiency of the turbine decreases very much.

Choi, Y. D.; Lim, J.. I.; Kim, C. G.; Kim, Y. T.; Lee, Y. H.

35

Hydraulic torque on the guide vane within the slight opening of pump turbine in turbine operating mode  

NASA Astrophysics Data System (ADS)

In a pumped storage power station, the units produce vibration and noise at times when the guide vanes rotate into the slight opening region during the turbine operating mode. According to this phenomenon, the simulation of transient flow in the units during the motion of the guide vane is carried out to investigate the variation of flow state in the process of startup and shutdown in turbine mode. The changing rate of hydraulic torque on a single guide vane is introduced to quantitatively represent the varying acuteness of the flow in the guide vanes and the possibility of the noise induced by the instable flow. The correlation between the frequency of noise and water head is summarized. The research indicates that the repeating reversal of fluid after load rejection is the hydraulic phenomenon which is the cause of the distributor vibration and noises within the slight opening, which is in accordance with the data recorded during the operation of the station. The effect of guide vanes closing law on the flow state in guide vanes and hydraulic torque on a single guide vane is analyzed.

Fan, H. G.; Yang, H. X.; Li, F. C.; Chen, N. X.

2014-12-01

36

Development of the helical reaction hydraulic turbine. Final technical report, July 1, 1996--June 30, 1998  

SciTech Connect

The present report contains the final results obtained during July 1996--July 1998. This report should be considered in association with the Annual Progress Report submitted in July 1997 due to the fact that not all of the intermediate results reflected in the Progress Report have been included in the Final Report. The aim of the project was to build a helical hydraulic turbine prototype and demonstrate its suitability and advantages as a novel apparatus to harness hydropower from ultra low-head rivers and other free water streams such as ocean currents or rivers without dams. The research objectives of the project are: Design, optimization and selection of the hydro foil section for the helical turbine; Design of the turbine for demonstration project; Construction and testing of the turbine module; Assessing test results and determining scale-up feasibility. The research conducted under this project has substantially exceeded the original goals including designing, constructing and testing of a scaled-up triple-helix turbine, as well as developing recommendations for application of the turbine for direct water pumping in irrigation systems and for future use in wind farms. Measurements collected during two years of turbine testing are kept in the PI files.

Gorlov, A.

1998-08-01

37

Internal hydraulic analysis of impeller rounding in centrifugal pumps as turbines  

SciTech Connect

The use of pumps as turbines in different applications has been gaining importance in the recent years, but the subject of hydraulic optimization still remains an open research problem. One of these optimization techniques that include rounding of the sharp edges at the impeller periphery (or turbine inlet) has shown tendencies of performance enhancement. In order to understand the effect of this hydraulic optimization, the paper introduces an analytical model in the pump as turbine control volume and brings out the functionalities of the internal variables classified under control variables consisting of the system loss coefficient and exit relative flow direction and under dependent variables consisting of net tangential flow velocity, net head and efficiency. The paper studies the effects of impeller rounding on a combination of radial flow and mixed flow pumps as turbines using experimental data. The impeller rounding is seen to have positive impact on the overall efficiency in different operating regions with an improvement in the range of 1-3%. The behaviour of the two control variables have been elaborately studied in which it is found that the system loss coefficient has reduced drastically due to rounding effects, while the extent of changes to the exit relative flow direction seems to be limited in comparison. The reasons for changes to these control variables have been physically interpreted and attributed to the behaviour of the wake zone at the turbine inlet and circulation within the impeller control volume. The larger picture of impeller rounding has been discussed in comparison with performance prediction models in pumps as turbines. The possible limitations of the analytical model as well as the test setup are also presented. The paper concludes that the impeller rounding technique is very important for performance optimization and recommends its application on all pump as turbine projects. It also recommends the standardization of the rounding effects over wide range of pump shapes including axial pumps. (author)

Singh, Punit; Nestmann, Franz [Institute of Water and River Basin Management (IWG), Karlsruhe Institute of Technology, Kaiser Str. 12, D 76131 Karlsruhe (Germany)

2011-01-15

38

Wind Turbine Contingency Control Through Generator De-Rating  

NASA Technical Reports Server (NTRS)

Maximizing turbine up-time and reducing maintenance costs are key technology drivers for wind turbine operators. Components within wind turbines are subject to considerable stresses due to unpredictable environmental conditions resulting from rapidly changing local dynamics. In that context, systems health management has the aim to assess the state-of-health of components within a wind turbine, to estimate remaining life, and to aid in autonomous decision-making to minimize damage to the turbine. Advanced contingency control is one way to enable autonomous decision-making by providing the mechanism to enable safe and efficient turbine operation. The work reported herein explores the integration of condition monitoring of wind turbines with contingency control to balance the trade-offs between maintaining system health and energy capture. The contingency control involves de-rating the generator operating point to achieve reduced loads on the wind turbine. Results are demonstrated using a high fidelity simulator of a utility-scale wind turbine.

Frost, Susan; Goebel, Kai; Balas, Mark

2013-01-01

39

CAN-Bus Based Distributed Control System for Hydraulic Turbine Blade Repairing Robot  

Microsoft Academic Search

\\u000a A CAN-bus (Controller Area Network) based distributed control system was designed for a mobile on-site hydraulic turbine blade\\u000a repairing robot (HTBRR). The system is composed of one supervisory station, seven joint servo nodes, and four accessory nodes.\\u000a Visual image sensing, virtual reality and graphic based path planning are implemented on the supervisory station, to improve\\u000a tele-operation. Each joint servo node

Kangtai Xiang; Zhenguo Sun; Hongjun Dai; Qiang Chen; Jiajun Liu

2010-01-01

40

Modelling roughness and acceleration effects with application to the flow in a hydraulic turbine  

NASA Astrophysics Data System (ADS)

This study reports the numerical predictions of flows over turbine blades, which include flow acceleration and deceleration. Two issues are addressed: (1) accurately predicting roughness effects, and (2) evaluating the performance of Reynolds-Averaged Navier-Stokes (RANS) simulations on moderately accelerating flows. For the present turbine surfaces, it is found that roughness correlations based on roughness surface slope better predict the roughness effects than both the correlations based on the moments of roughness height statistics and the IEC standard approach. It is shown that RANS simulations reproduce the flow evolution over rough-wall accelerating turbulent boundary layers, although, on a smooth wall, they fail to capture strong non-equilibrium flow behaviours. Finally, a hydraulic turbine simulation is performed to show the significant roughness impact on the total losses.

Yuan, J.; Nicolle, J.; Piomelli, U.; Giroux, A.-M.

2014-12-01

41

Fatigue Analysis of the Piston Rod in a Kaplan Turbine Based on Crack Propagation under Unsteady Hydraulic Loads  

NASA Astrophysics Data System (ADS)

As an important component of the blade-control system in Kaplan turbines, piston rods are subjected to fluctuating forces transferred by the turbines blades from hydraulic pressure oscillations. Damage due to unsteady hydraulic loads might generate unexpected down time and high repair cost. In one running hydropower plant, the fracture failure of the piston rod was found twice at the same location. With the transient dynamic analysis, the retainer ring structure of the piston rod existed a relative high stress concentration. This predicted position of the stress concentration agreed well with the actual fracture position in the plant. However, the local strain approach was not able to explain why this position broke frequently. Since traditional structural fatigue analyses use a local stress strain approach to assess structural integrity, do not consider the effect of flaws which can significantly degrade structural life. Using linear elastic fracture mechanism (LEFM) approaches that include the effect of flaws is becoming common practice in many industries. In this research, a case involving a small semi-ellipse crack was taken into account at the stress concentration area, crack growth progress was calculated by FEM. The relationship between crack length and remaining life was obtained. The crack propagation path approximately agreed with the actual fracture section. The results showed that presence of the crack had significantly changed the local stress and strain distributions of the piston rod compared with non-flaw assumption.

Liu, X.; Luo, Y. Y.; Wang, Z. W.

2014-12-01

42

33. TURBINE HALL, ORIGINAL TURBO GENERATOR, INTACT CONDENSER Philadelphia ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

33. TURBINE HALL, ORIGINAL TURBO GENERATOR, INTACT CONDENSER - Philadelphia Electric Company, Richmond Power Station, Southeast end of Lewis Street along Delaware River, Philadelphia, Philadelphia County, PA

43

Failure analysis of gas turbine generator cooling fan blades  

Microsoft Academic Search

Since the optimum operation of a generator is highly affected by increasing in temperature, a cooling system is used to control the temperature. Employing a fan as a cooling system for the generator at the end sides of its rotor is a practical method [Montazer Ghaem Gas Turbine Power Plant. Gas turbine generator manual, Iran, 2004]. In some cases, fracture

S. E. Moussavi Torshizi; S. M. Yadavar Nikravesh; A. Jahangiri

2009-01-01

44

Miniature Gas-Turbine Power Generator  

NASA Technical Reports Server (NTRS)

A proposed microelectromechanical system (MEMS) containing a closed- Brayton-cycle turbine would serve as a prototype of electric-power generators for special applications in which high energy densities are required and in which, heretofore, batteries have been used. The system would have a volume of about 6 cm3 and would operate with a thermal efficiency >30 percent, generating up to 50 W of electrical power. The energy density of the proposed system would be about 10 times that of the best battery-based systems now available, and, as such, would be comparable to that of a fuel cell. The working gas for the turbine would be Xe containing small quantities of CO2, O2, and H2O as gaseous lubricants. The gas would be contained in an enclosed circulation system, within which the pressure would typically range between 5 and 50 atm (between 0.5 and 5 MPa). The heat for the Brayton cycle could be supplied by any of a number of sources, including a solar concentrator or a combustor burning a hydrocarbon or other fuel. The system would include novel heat-transfer and heat-management components. The turbine would be connected to an electric power generator/starter motor. The system would include a main rotor shaft with gas bearings; the bearing surfaces would be made of a ceramic material coated with nanocrystalline diamond. The shaft could withstand speed of 400,000 rpm or perhaps more, with bearing-wear rates less than 10(exp -)4 those of silicon bearings and 0.05 to 0.1 those of SiC bearings, and with a coefficient of friction about 0.1 that of Si or SiC bearings. The components of the system would be fabricated by a combination of (1) three-dimensional xray lithography and (2) highly precise injection molding of diamond-compatible metals and ceramic materials. The materials and fabrication techniques would be suitable for mass production. The disadvantages of the proposed system are that unlike a battery-based system, it could generate a perceptible amount of sound, and, if it were to burn fuel, then it would also generate exhaust, similarly to other combustion-based power sources.

Wiberg, Dean; Vargo, Stephen; White, Victor; Shcheglov, Kirill

2003-01-01

45

Wind Turbine Generator System Power Performance Test Report for the ARE442 Wind Turbine  

SciTech Connect

This report summarizes the results of a power performance test that NREL conducted on the ARE 442 wind turbine. This test was conducted in accordance with the International Electrotechnical Commission's (IEC) standard, Wind Turbine Generator Systems Part 12: Power Performance Measurements of Electricity Producing Wind Turbines, IEC 61400-12-1 Ed.1.0, 2005-12. However, because the ARE 442 is a small turbine as defined by IEC, NREL also followed Annex H that applies to small wind turbines. In these summary results, wind speed is normalized to sea-level air density.

van Dam, J.; Jager, D.

2010-02-01

46

On-Shore Central Hydraulic Power Generation for Wind and Tidal Energy  

NASA Technical Reports Server (NTRS)

Tidal energy, offshore wind energy, and onshore wind energy can be converted to electricity at a central ground location by means of converting their respective energies into high-pressure hydraulic flows that are transmitted to a system of generators by high-pressure pipelines. The high-pressure flows are then efficiently converted to electricity by a central power plant, and the low-pressure outlet flow is returned. The Department of Energy (DOE) is presently supporting a project led by Sunlight Photonics to demonstrate a 15 kW tidal hydraulic power generation system in the laboratory and possibly later submerged in the ocean. All gears and submerged electronics are completely eliminated. A second portion of this DOE project involves sizing and costing a 15 MW tidal energy system for a commercial tidal energy plant. For this task, Atlantis Resources Corporation s 18-m diameter demonstrated tidal blades are rated to operate in a nominal 2.6 m/sec tidal flow to produce approximately one MW per set of tidal blades. Fifteen units would be submerged in a deep tidal area, such as in Maine s Western Passage. All would be connected to a high-pressure (20 MPa, 2900 psi) line that is 35 cm ID. The high-pressure HEPG fluid flow is transported 500-m to on-shore hydraulic generators. HEPG is an environmentally-friendly, biodegradable, watermiscible fluid. Hydraulic adaptations to ORPC s cross-flow turbines are also discussed. For 15 MW of wind energy that is onshore or offshore, a gearless, high efficiency, radial piston pump can replace each set of top-mounted gear-generators. The fluid is then pumped to a central, easily serviceable generator location. Total hydraulic/electrical efficiency is 0.81 at full rated wind or tidal velocities and increases to 0.86 at 1/3 rated velocities.

Jones, Jack A.; Bruce, Allan; Lim, Steven; Murray, Luke; Armstrong, Richard; Kimbrall, Richard; Cook-Chenault, Kimberly; DeGennaro, Sean

2012-01-01

47

Performance characteristics of aerodynamically optimum turbines for wind energy generators  

NASA Technical Reports Server (NTRS)

This paper presents a brief discussion of the aerodynamic methodology for wind energy generator turbines, an approach to the design of aerodynamically optimum wind turbines covering a broad range of design parameters, some insight on the effect on performance of nonoptimum blade shapes which may represent lower fabrication costs, the annual wind turbine energy for a family of optimum wind turbines, and areas of needed research. On the basis of the investigation, it is concluded that optimum wind turbines show high performance over a wide range of design velocity ratios; that structural requirements impose constraints on blade geometry; that variable pitch wind turbines provide excellent power regulation and that annual energy output is insensitive to design rpm and solidity of optimum wind turbines.

Rohrbach, C.; Worobel, R.

1975-01-01

48

The General Electric MOD-1 wind turbine generator program  

NASA Technical Reports Server (NTRS)

The design, fabrication, installation and checkout of MOD-1, a megawatt class wind turbine generator which generates utility grade electrical power, is described. A MOD-1/MOD-1A tradeoff study is discussed.

Poor, R. H.; Hobbs, R. B.

1979-01-01

49

Numerical simulation of pulsation processes in hydraulic turbine based on 3D model of cavitating flow  

NASA Astrophysics Data System (ADS)

A new approach was proposed for simulation of unsteady cavitating flow in the flow passage of a hydraulic power plant. 1D hydro-acoustics equations are solved in the penstock domain. 3D equations of turbulent flow of isothermal compressible liquid-vapor mixture are solved in the turbine domain. Cavitation is described by a transfer equation for liquid phase with a source term which is responsible for evaporation and condensation. The developed method was applied for simulation of pulsations in pressure, discharge, and total energy propagating along the flow conduit of the hydraulic power plant. Simulation results are in qualitative and quantitative agreement with experiment. The influence of key physical and numerical parameters like discharge, cavitation number, penstock length, time step, and vapor density on simulation results was studied.

Panov, L. V.; Chirkov, D. V.; Cherny, S. G.; Pylev, I. M.

2014-01-01

50

Nonlinear deformation of shells of the volute chambers of hydraulic turbines in an elastic medium  

SciTech Connect

Volute chambers are an important part of the water channels in high-pressure hydroelectric power stations. The chambers generally have the form of a torus with a variable profile. The shells of the chamber interact with the surrounding concrete through their external surface. While other studies have examined aspects of the design of volute chambers, the authors here present a solution of a problem on the nonlinear deformation of the shells of the volute chambers of hydraulic turbines interacting on one side with a concrete medium.

Aronson, A.Y.; Bazhenov, V.A.; Gotsulayk, E.A.; Gulyaev, V.I.; Ogloblya, A.I.

1985-12-01

51

Design evolution of large wind turbine generators  

NASA Technical Reports Server (NTRS)

During the past five years, the goals of economy and reliability have led to a significant evolution in the basic design--both external and internal--of large wind turbine systems. To show the scope and nature of recent changes in wind turbine designs, development of three types are described: (1) system configuration developments; (2) computer code developments; and (3) blade technology developments.

Spera, D. A.

1979-01-01

52

Durability Challenges for Next Generation of Gas Turbine Engine Materials  

NASA Technical Reports Server (NTRS)

Aggressive fuel burn and carbon dioxide emission reduction goals for future gas turbine engines will require higher overall pressure ratio, and a significant increase in turbine inlet temperature. These goals can be achieved by increasing temperature capability of turbine engine hot section materials and decreasing weight of fan section of the engine. NASA is currently developing several advanced hot section materials for increasing temperature capability of future gas turbine engines. The materials of interest include ceramic matrix composites with 1482 - 1648 C temperature capability, advanced disk alloys with 815 C capability, and low conductivity thermal barrier coatings with erosion resistance. The presentation will provide an overview of durability challenges with emphasis on the environmental factors affecting durability for the next generation of gas turbine engine materials. The environmental factors include gaseous atmosphere in gas turbine engines, molten salt and glass deposits from airborne contaminants, impact from foreign object damage, and erosion from ingestion of small particles.

Misra, Ajay K.

2012-01-01

53

32. TURBINE HALL, ORIGINAL TURBO GENERATOR, DETAILS AT CONDENSER, LOOKING ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

32. TURBINE HALL, ORIGINAL TURBO GENERATOR, DETAILS AT CONDENSER, LOOKING SOUTHEAST - Philadelphia Electric Company, Richmond Power Station, Southeast end of Lewis Street along Delaware River, Philadelphia, Philadelphia County, PA

54

31. TURBINE HALL, ORIGINAL TURBO GENERATOR, DETAILS AT CONDENSER, LOOKING ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

31. TURBINE HALL, ORIGINAL TURBO GENERATOR, DETAILS AT CONDENSER, LOOKING SOUTHEAST - Philadelphia Electric Company, Richmond Power Station, Southeast end of Lewis Street along Delaware River, Philadelphia, Philadelphia County, PA

55

Hydraulics.  

ERIC Educational Resources Information Center

This curriculum guide contains a course in hydraulics to train entry-level workers for automotive mechanics and other fields that utilize hydraulics. The module contains 14 instructional units that cover the following topics: (1) introduction to hydraulics; (2) fundamentals of hydraulics; (3) reservoirs; (4) lines, fittings, and couplers; (5)…

Decker, Robert L.; Kirby, Klane

56

Flow Characteristics in an Augmentation Channel of a Direct Drive Turbine for Wave Power Generation  

NASA Astrophysics Data System (ADS)

Cross flow turbine also known as Banki turbine, is a hydraulic turbine that may be classified as an impulse turbine. At present it has gained interest in small and low head establishments because of its simple structure, cost effectiveness and low maintenance. Therefore, the present paper expands on this idea and aims at implementing the Direct Drive Turbine (DDT) for wave power generation. Wave power has enormous amount of energy which is environmentally friendly, renewable and can be exploited to satisfy the energy needs. A Numerical Wave Tank (NWT) was used to simulate the sea conditions and after obtaining desired wave properties; the augmentation channel plus the front guide nozzle and rear chamber were integrated to the NWT. The augmentation channel consisted of a front nozzle, rear nozzle and an internal fluid region which represented the turbine housing. The front and rear nozzle were geometrically identical. Two different nozzle configurations were studied; spiral rear wall type and a straight rear wall type. In addition to this, the effect of front guide nozzle divergent angle was also studied. The general idea is to investigate how different augmentation channel geometry and front guide nozzle divergent angle affects the flow, the water horse power and the first stage (primary stage) energy conversion. The analysis was performed using a commercial CFD code of the ANSYS-CFX. The results of the flow in an augmentation channel of the Direct Drive Turbine in oscillating flow for all the cases are presented by means of pressure and velocity vectors. The water horse power (WHP) and first stage energy conversion for the models are also presented.

Prasad, Deepak; Zullah, Mohammed Asid; Choi, Young-Do; Lee, Young-Ho

2010-06-01

57

ERCOT's Dynamic Model of Wind Turbine Generators: Preprint  

SciTech Connect

By the end of 2003, the total installed wind farm capacity in the Electric Reliability Council of Texas (ERCOT) system was approximately 1 gigawatt (GW) and the total in the United States was about 5 GW. As the number of wind turbines installed throughout the United States increases, there is a greater need for dynamic wind turbine generator models that can properly model entire power systems for different types of analysis. This paper describes the ERCOT dynamic models and simulations of a simple network with different types of wind turbine models currently available.

Muljadi, E.; Butterfield, C. P.; Conto, J.; Donoho, K.

2005-08-01

58

Bridging the gap between metallurgy and fatigue reliability of hydraulic turbine runners  

NASA Astrophysics Data System (ADS)

The failure of hydraulic turbine runners is a very rare event. Hence, in order to assess the reliability of these components, one cannot rely on statistical models based on the number of failures in a given population. However, as there is a limited number of degradation mechanisms involved, it is possible to use physically-based reliability models. Such models are more complicated but have the advantage of being able to account for physical parameters in the prediction of the evolution of runner degradation. They can therefore propose solutions to help improve reliability. With the use of such models, the effect of materials properties on runner reliability can easily be illustrated. This paper will present a brief review of the Kitagawa-Takahashi diagram that links the damage tolerance approach, based on fracture mechanics, to the stress or strain-life approaches. This diagram is at the centre of the reliability model used in this study. Using simplified response spectra obtained from on-site runner stress measurements, the paper will show how fatigue reliability is impacted by materials fatigue properties, namely fatigue crack propagation behaviour and fatigue limit obtained on S-N curves. It will also present a review of the most important microstructural features of 13%Cr- 4%Ni stainless steels used for runner manufacturing and will review how they influence fatigue properties in an effort to bridge the gap between metallurgy and turbine runners reliability.

Thibault, D.; Gagnon, M.; Godin, S.

2014-12-01

59

Metallurgical and fatigue assessments of welds in cast welded hydraulic turbine runners  

NASA Astrophysics Data System (ADS)

Decades of hydraulic turbine operation around the world have shown one undeniable fact; welded turbine runners can be prone to fatigue cracking, especially in the vicinity of welds. In this regard, three factors are essential to consider in runner fatigue assessments: (1) the runner's design, which can induce stress concentrations in the fillets, (2) the casting process, which inherently creates defects such as shrinkage cavities and (3) the welding process, which induces significant residual stresses as well as a heat affected zone in the cast pieces near the interface with the filler metal. This study focuses on the latter, the welding process, with emphasis on the influence of the heat affected zone on the runner's fatigue behavior. In a recently concluded study by a large research consortium in Montreal, the microstructure and fatigue crack propagation properties of a CA6NM runner weld heat affected zone were thoroughly investigated to find if this zone deteriorates the runner's resistance to fatigue cracking. The main results showed that this zone's intrinsic fatigue crack propagation resistance is only slightly lower than the unaffected base metal because of its somewhat finer martensitic microstructure leading to a less tortuous crack path. However, it was also confirmed that weld-induced residual stresses represent the dominant influencing factor regarding fatigue crack propagation, though post-weld heat treatments are usually very effective in reducing such residual stresses. This paper aims to further confirm, through a case study, that the weld-induced heat affected zone does not compromise the reliability of welded turbine runners when its fatigue crack propagation properties are considered in fatigue damage models.

Trudel, A.; Sabourin, M.

2014-12-01

60

Hydraulics.  

ERIC Educational Resources Information Center

These instructional materials provide an orientation to hydraulics for use at the postsecondary level. The first of 12 sections presents an introduction to hydraulics, including discussion of principles of liquids, definitions, liquid flow, the two types of hydraulic fluids, pressure gauges, and strainers and filters. The second section identifies…

Engelbrecht, Nancy; And Others

61

Topping turbine generator in blast furnace power house  

SciTech Connect

A project to install a 22 megawatt topping turbine for waste heat utilization is described in this paper. Selection criteria, design, installation, startup, and initial operation are described in detail. The facility was initially depressurizing and desuperheating steam sufficient to generator 8 MW(e). Analysis showed that, with the addition of a low pressure feedwater heater, the capacity of the 900 psig boilers could be increased. This allowed a turbine generator capacity increase and a shutdown of the low pressure boilers. Minor startup problems were identified and corrected, and the project is generating significant revenue.

Mooney, R.E. [REM Engineering, Roswell, GA (United States); Ganga, R.C. [The McBurney Corp., Norcross, GA (United States); Owen, P. [US Steel, Birmingham, AL (United States)

1996-12-31

62

9. VIEW OF FRANCIS TURBINE, GENERATOR DRIVE SHAFT. NOTE ORIGINAL ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

9. VIEW OF FRANCIS TURBINE, GENERATOR DRIVE SHAFT. NOTE ORIGINAL EXCITER AND GENERATOR RHEOSTATS ATOP CONTROL PANEL AT REAR. CONTROL PANEL IS ORIGINAL EXCEPT FOR HORIZONTAL TOP PANEL WITH CLOCK AT LEFT AND SYNCHROSCOPE AT RIGHT, LOOKING EAST - Centerville Hydroelectric System, Powerhouse, Butte Creek, Centerville, Butte County, CA

63

Advanced Wind Turbine Program Next Generation Turbine Development Project: June 17, 1997--April 30, 2005  

SciTech Connect

This document reports the technical results of the Next Generation Turbine Development Project conducted by GE Wind Energy LLC. This project is jointly funded by GE and the U.S. Department of Energy's National Renewable Energy Laboratory.The goal of this project is for DOE to assist the U.S. wind industry in exploring new concepts and applications of cutting-edge technology in pursuit of the specific objective of developing a wind turbine that can generate electricity at a levelized cost of energy of $0.025/kWh at sites with an average wind speed of 15 mph (at 10 m height).

GE Wind Energy, LLC

2006-05-01

64

Fuzzy-polar control of wind-turbine generator  

SciTech Connect

This paper presents a wind-turbine blade pitch angle controller based on fuzzy polar technique. the technique takes advantage of fuzzy-linguistic modeling in expressing the natural non-linearity or imprecision of the wind-turbine system in determining pitch angles for speed and power regulation. The fuzzy-polar method presents wind-turbine state in the phase-plane in terms of its rotational speed deviation and acceleration. The state vectors thus derived serve as an indicator of the magnitude of departure from the nominal operating point. In order to shift operating state back to the phase plane origin, an acceleration or deceleration control is applied through the pitch-angle adjustment mechanism as defined by the fuzzy-linguistic control law. The performance of the pitch control design method is demonstrated on a simulated wind-turbine-driven synchronous generator.

Idowu, P. [Penn State Univ., Middletown, PA (United States)

1995-12-31

65

The impact of inlet angle and outlet angle of guide vane on pump in reversal based hydraulic turbine performance  

NASA Astrophysics Data System (ADS)

In this paper, in order to research the impact of inlet angle and outlet angle of guide vane on hydraulic turbine performance, a centrifugal pump in reversal is adopted as turbine. A numerical simulation method is adopted for researching outer performance and flow field of turbine. The results show: inlet angle has a crucial role to turbine, to the same flow, there is a noticeable decline for the efficiency and head of turbine with the inlet angle increases. At the best efficiency point(EFP),to a same inlet angle, when the inlet angle greater than inlet angle, velocity circulation in guide vane outlet decreases, which lead the efficiency of turbine to reduce, Contrarily, the efficiency rises. With the increase of inlet angle and outlet angle, the EFP moves to the big flow area and the uniformity of pressure distribution becomes worse. The paper indicates that the inlet angle and outlet angle have great impact on the turbine performance, and the best combination exists for the inlet angle and outlet angle of the guide vane.

Shi, F. X.; Yang, J. H.; Wang, X. H.; Zhang, R. H.; Li, C. E.

2012-11-01

66

Preliminary design of a 100 kW turbine generator  

NASA Technical Reports Server (NTRS)

The National Science Foundation and the Lewis Research Center have engaged jointly in a Wind Energy Program which includes the design and erection of a 100 kW wind turbine generator. The machine consists primarily of a rotor turbine, transmission, shaft, alternator, and tower. The rotor, measuring 125 feet in diameter and consisting of two variable pitch blades operates at 40 rpm and generates 100 kW of electrical power at 18 mph wind velocity. The entire assembly is placed on top of a tower 100 feet above ground level.

Puthoff, R. L.; Sirocky, P. J.

1974-01-01

67

The 100 kW experimental wind turbine generator project  

NASA Technical Reports Server (NTRS)

The Energy Research and Development Administration and the NASA Lewis Research Center engaged jointly in a Wind Energy Program which included the design and erection of a 100 kW wind turbine generator. This test machine consists of a rotor turbine, transmission, shaft, alternator, and tower. The rotor, measuring 125 feet in diameter and consisting of two variable pitch blades, operates at 40 rpm and generates 100 kW of electrical power at a wind velocity of 18 mph. The entire assembly is placed on top of a tower 100 feet above ground level. The machine was scheduled to be ready for operation in August, 1975.

Puthoff, R. L.; Sirocky, P.

1975-01-01

68

Calculation of guaranteed mean power from wind turbine generators  

NASA Technical Reports Server (NTRS)

A method for calculating the 'guaranteed mean' power output of a wind turbine generator is proposed. The term 'mean power' refers to the average power generated at specified wind speeds during short-term tests. Correlation of anemometers, the method of bins for analyzing non-steady data, the PROP Code for predicting turbine power, and statistical analysis of deviations in test data from theory are discussed. Guaranteed mean power density for the Clayton Mod-OA system was found to be 8 watts per square meter less than theoretical power density at all power levels, with a confidence level of 0.999. This amounts to 4 percent of rated power.

Spera, D. A.

1981-01-01

69

Optical fiber instrumentation of a high power generator and turbine  

NASA Astrophysics Data System (ADS)

The instrumentation of a high power generator and its complementary systems including the turbine bearings is presented and discussed. The generator consists of a 175MW hydroelectric generator installed in the Salto Osório power plant in the southern region of Brazil. Results show good agreement with the already existing instrumentation and demonstrate the technology potential for a full optical fiber sensing system to monitor these large machines.

da Silva, Erlon Vagner; Dreyer, Uilian José; de Morais Sousa, Kleiton; Babinski, Valderi Junot; Somenzi, Jonas; Mezzadri, Felipe; de Lourenço Junior, Ivo; Martelli, Cicero; Cardozo da Silva, Jean Carlos

2013-05-01

70

Methods and apparatus for cooling wind turbine generators  

DOEpatents

A wind turbine generator includes a stator having a core and a plurality of stator windings circumferentially spaced about a generator longitudinal axis. A rotor is rotatable about the generator longitudinal axis, and the rotor includes a plurality of magnetic elements coupled to the rotor and cooperating with the stator windings. The magnetic elements are configured to generate a magnetic field and the stator windings are configured to interact with the magnetic field to generate a voltage in the stator windings. A heat pipe assembly thermally engaging one of the stator and the rotor to dissipate heat generated in the stator or rotor.

Salamah, Samir A. (Niskayuna, NY); Gadre, Aniruddha Dattatraya (Rexford, NY); Garg, Jivtesh (Schenectady, NY); Bagepalli, Bharat Sampathkumaran (Niskayuna, NY); Jansen, Patrick Lee (Alplaus, NY); Carl, Jr., Ralph James (Clifton Park, NY)

2008-10-28

71

Hydraulics.  

ERIC Educational Resources Information Center

Designed for use in courses where students are expected to become proficient in the area of hydraulics, including diesel engine mechanic programs, this curriculum guide is comprised of fourteen units of instruction. Unit titles include (1) Introduction, (2) Fundamentals of Hydraulics, (3) Reservoirs, (4) Lines, Fittings, and Couplers, (5) Seals,…

Decker, Robert L.

72

Wind turbine generator with improved operating subassemblies  

DOEpatents

A wind turbine includes a yaw spring return assembly to return the nacelle from a position to which it has been rotated by yawing forces, thus preventing excessive twisting of the power cables and control cables. It also includes negative coning restrainers to limit the bending of the flexible arms of the rotor towards the tower, and stop means on the rotor shaft to orient the blades in a vertical position during periods when the unit is upwind when the wind commences. A pendulum pitch control mechanism is improved by orienting the pivot axis for the pendulum arm at an angle to the longitudinal axis of its support arm, and excessive creep is of the synthetic resin flexible beam support for the blades is prevented by a restraining cable which limits the extent of pivoting of the pendulum during normal operation but which will permit further pivoting under abnormal conditions to cause the rotor to stall.

Cheney, Jr., Marvin C. (24 Stonepost Rd., Glastonbury, CT 06033)

1985-01-01

73

Degradation of Phosphate Ester Hydraulic Fluid in Power Station Turbines Investigated by a Three-Magnet Unilateral Magnet Array  

PubMed Central

A three-magnet array unilateral NMR sensor with a homogeneous sensitive spot was employed for assessing aging of the turbine oils used in two different power stations. The Carr-Purcell-Meiboom-Gill (CPMG) sequence and Inversion Recovery-prepared CPMG were employed for measuring the 1H-NMR transverse and longitudinal relaxation times of turbine oils with different service status. Two signal components with different lifetimes were obtained by processing the transverse relaxation curves with a numeric program based on the Inverse Laplace Transformation. The long lifetime components of the transverse relaxation time T2eff and longitudinal relaxation time T1 were chosen to monitor the hydraulic fluid aging. The results demonstrate that an increase of the service time of the turbine oils clearly results in a decrease of T2eff,long and T1,long. This indicates that the T2eff,long and T1,long relaxation times, obtained from the unilateral magnetic resonance measurements, can be applied as indices for degradation of the hydraulic fluid in power station turbines. PMID:24736132

Guo, Pan; He, Wei; García-Naranjo, Juan C.

2014-01-01

74

Single module pressurized fuel cell turbine generator system  

DOEpatents

A pressurized fuel cell system (10), operates within a common pressure vessel (12) where the system contains fuel cells (22), a turbine (26) and a generator (98) where preferably, associated oxidant inlet valve (52), fuel inlet valve (56) and fuel cell exhaust valve (42) are outside the pressure vessel.

George, Raymond A. (Pittsburgh, PA); Veyo, Stephen E. (Murrysville, PA); Dederer, Jeffrey T. (Valencia, PA)

2001-01-01

75

Control strategy of a variable speed wind turbine with multipole permanent magnet synchronous generator  

E-print Network

Control strategy of a variable speed wind turbine with multipole permanent magnet synchronous magnet syn- chronous generator (PMSG) and full scale IGBT power converter. A comprehensive dynamical values. Keywords: permanent magnet synchronous generator, variable speed wind turbine, direct driven wind

76

Composite rotor blades for wind turbine generators  

NASA Astrophysics Data System (ADS)

The materials, techniques, and methods used to construct a 150 ft test blade, two 31 ft blades for a 40 kW WECS, and rotor blades for the Mod-1 wind turbine are described. Considerations of strength, stiffness, and mass distributions, as well as cost, led to the choice of filament wound fiberglass/epoxy material using transverse filament tape which has structural fibers running across the width of the tape. A number of 90 deg windings were added to the rotor after tape winding to provide compaction and hoop strength. Curing comprised five hours at 180 F. The Mod-1 blades were required to match the steel blades in weight, stiffness, deflection, and frequencies. The finished product weighed 20,000 lb and featured a metal tip cap and braided wire trailing edge strap for lightning protection. The 40 kW was a NACA 23018 in the center and 23012 at the tip, while the Mod-1 blade was a NACA 23025 in the center and 23015 at the tip.

Weigel, W. D.

77

Current turbine for water pumping and electricity generation  

SciTech Connect

This paper describes work on Phase I of ''Mini Hydropower Research and Development Project'' in the Department of Mechanical Engineering, University of Khartoum, in cooperation with the National Council for Research in Sudan. The main purpose of Phase I of the project has been to demonstrate and evaluate the use of water current energy for powering small-scale pumping units and for generating electricity. Power requirements for pumping water for irrigation on typical small land holdings in the Sudan will be of the order of 5-10 Kw. The same sizes of power should sufficiently meet power requirements of home factories for processing farm produce of these lands and of domestic uses. A vertical shaft impulse turbine of innovative design has been built in the Faculty of Engineering, University of Khartoum, to extract energy from water current of canals, rivers or streams. The useful shaft power from the turbine is used for pumping water or electricity generation. The turbine set is suspended from a floating pontoon (made from plastic drums) which is secured in the current by means of two horizontal supporting poles and steel cables. Field trials of a number of model turbine systems are currently being carried out and valuable findings are being obtained about the desirable features to be developed in these machines. However, concrete results are still to be finalized with a view to facilitating analytical design of pump-turbine and generatorturbine systems. Indications are that this work should lead to an efficient, cheap and simple-to-build current turbine. Detailed information on system design and performance are expected to be ready in time for the conference.

Mohamed, A.I.E.

1983-12-01

78

Hybrid Power Generation System Using Offshore-Wind Turbine and Tidal Turbine for Power Fluctuation Compensation (HOT-PC)  

Microsoft Academic Search

Hybrid power generation system using Offshore-wind turbine and Tidal turbine for Power fluctuation Compensation (HOT-PC) is an autonomous power system. Electric power is generated from both offshore wind and tidal and is distributed over the load system. Power quality problems such as frequency fluctuations and voltage sags, which arise due to a fault or a pulsed load, can cause interruptions

Mohammad Lutfur Rahman; Shunsuke Oka; Yasuyuki Shirai

2010-01-01

79

The Parameter of Automatic Voltage Regulator's Effect on Steady State Stability Limit of Turbine Generator  

Microsoft Academic Search

The steady state stability limit of turbine generator with automatic voltage regulator (AVR) extends steam turbine's safe range under exciting operation compared to generator without AVR. Therefore, Paper analyzes the parameter of AVR's effect on steady state stability limit of turbine generator, and verifies the conclusion with the simulation model in Matlab\\/Simulink environment.

Yong-Gang Li; Jun-Jie Fu; Yan-Jun Zhao; Qiang Liu

2008-01-01

80

Testing Small Wind Turbine Generators: Design of a Driving Dynamometer Stephen Rehmeyer Pepe  

E-print Network

Testing Small Wind Turbine Generators: Design of a Driving Dynamometer by Stephen Rehmeyer Pepe Sc, Berkeley Spring 2007 #12;Testing Small Wind Turbine Generators: Design of a Driving Dynamometer Copyright c 2007 by Stephen Rehmeyer Pepe #12;Abstract Testing Small Wind Turbine Generators: Design of a Driving

Kammen, Daniel M.

81

Optimization of a Small Passive Wind Turbine Generator with Multiobjective Genetic Algorithms  

E-print Network

Algorithms (MOGAs) are used for the design of a small wind turbine generator (WTG) coupled to a DC bus choice of the system design variables associated with the wind turbine generator sizing (especiallyOptimization of a Small Passive Wind Turbine Generator with Multiobjective Genetic Algorithms A

Paris-Sud XI, Université de

82

Fire-retardant lubricant for turbine generators. Final report. [PWR  

SciTech Connect

The use of a fire resistant fluid in steam turbine generator lubrication systems would reduce the fire risks associated with current mineral lubricating oils. This project was directed toward determining the fesibility of modifying an existing Westinghouse lubrication system to use a phosphate ester lubricating fluid. The effects of the fluid on major components of the lubrication system including oil supply system, bearings, and generator hydrogen seal system were investigated. Performance and material compatibility impact on system components are identified and modifications recommended where required. Estimates of major modification costs are presented. The results of this study indicate that, with appropriate system modifications, a phosphate ester fluid can be an effective and reliable steam turbine generator lubricant. Recommendations are presented for component verification testing.

Pankowiecki, J.

1983-01-01

83

Saving energy costs with your condensing turbine generator  

SciTech Connect

Pulp and paper industry has been using steam turbines to generate power and reduce energy costs for many years. The operation of a condensing turbine in an industrial sewer plant is similar in many respects to the operation of a conventional fossil-fuel-fired utility station. Utility companies focus on converting fuel energy into electricity at the lowest possible cost. Thus they can usually sell power at a price that is lower than the cost of generating condensing power in an industrial plant if this power comes from purchased fuel and the comparison includes the capital costs. In most pulp mills, installing a condensing turbine to reduce energy costs would not be an attractive investment. This paper presents two analyses. The first considers the economics of loading up a turbine condensing section that is normally operating at low flow. This requires no capital investment, and savings depend on the relative costs of purchased fuel and electricity. The second analysis considers utilization of low-grade condenser heat to increase the temperature of process water, thereby reducing purchased energy costs. This requires some capital investment and has practical application in mills where the process water supply is cold during much of the year.

Hein, A.G. (Stothert Engineering Ltd., 155 W. Georgia St., Vancouver, British Columbia V6E 3N7 (CA))

1991-07-01

84

Site matching of wind turbine generators: A case study  

SciTech Connect

Site matching of wind turbine generators is investigated based on appropriate selection of statistical models and means of wind speed data. The wind speed means are computed using arithmetic mean, root mean square and cubic mean cuberoot. Wind Speed frequency distributions are modeled using Weibull and Rayleigh probability density functions. Wind speed data of an existing wind power station, located at Kappadagudda, Karnataka, India, is used for computational purposes. The analytically obtained capacity factors are validated by comparing with the actual capacity factors obtained at Kappadagudda. It is observed that the capacity factors computed from the Weibull statistical model using cubic mean of wind speed data fairly match the actual capacity factors obtained from Kappadagudda wind power station. Various commercially available wind turbine generators are used for site matching study. The model described in the paper is useful for planning of wind power stations as it can be applied for accurate assessment of wind power potential at a site.

Jangamshetti, S.H.; Rau, V.G.

1999-12-01

85

Advanced Combustion Systems for Next Generation Gas Turbines  

SciTech Connect

Next generation turbine power plants will require high efficiency gas turbines with higher pressure ratios and turbine inlet temperatures than currently available. These increases in gas turbine cycle conditions will tend to increase NOx emissions. As the desire for higher efficiency drives pressure ratios and turbine inlet temperatures ever higher, gas turbines equipped with both lean premixed combustors and selective catalytic reduction after treatment eventually will be unable to meet the new emission goals of sub-3 ppm NOx. New gas turbine combustors are needed with lower emissions than the current state-of-the-art lean premixed combustors. In this program an advanced combustion system for the next generation of gas turbines is being developed with the goal of reducing combustor NOx emissions by 50% below the state-of-the-art. Dry Low NOx (DLN) technology is the current leader in NOx emission technology, guaranteeing 9 ppm NOx emissions for heavy duty F class gas turbines. This development program is directed at exploring advanced concepts which hold promise for meeting the low emissions targets. The trapped vortex combustor is an advanced concept in combustor design. It has been studied widely for aircraft engine applications because it has demonstrated the ability to maintain a stable flame over a wide range of fuel flow rates. Additionally, it has shown significantly lower NOx emission than a typical aircraft engine combustor and with low CO at the same time. The rapid CO burnout and low NOx production of this combustor made it a strong candidate for investigation. Incremental improvements to the DLN technology have not brought the dramatic improvements that are targeted in this program. A revolutionary combustor design is being explored because it captures many of the critical features needed to significantly reduce emissions. Experimental measurements of the combustor performance at atmospheric conditions were completed in the first phase of the program. Emissions measurements were obtained over a variety of operating conditions. A kinetics model is formulated to describe the emissions performance. The model is a tool for determining the conditions for low emission performance. The flow field was also modeled using CFD. A first prototype was developed for low emission performance on natural gas. The design utilized the tools anchored to the atmospheric prototype performance. The 1/6 scale combustor was designed for low emission performance in GE's FA+e gas turbine. A second prototype was developed to evaluate changes in the design approach. The prototype was developed at a 1/10 scale for low emission performance in GE's FA+e gas turbine. The performance of the first two prototypes gave a strong indication of the best design approach. Review of the emission results led to the development of a 3rd prototype to further reduce the combustor emissions. The original plan to produce a scaled-up prototype was pushed out beyond the scope of the current program. The 3rd prototype was designed at 1/10 scale and targeted further reductions in the full-speed full-load emissions.

Joel Haynes; Jonathan Janssen; Craig Russell; Marcus Huffman

2006-01-01

86

Examination of wind turbine generator models response to disturbances  

Microsoft Academic Search

The paper discusses wind turbine generator (WTG) dynamic models intended for power system stability simulations. Presented are results of an examination performed for models of different variable-speed pitch-regulated WTGs. Subject to examination were models' dynamic response to grid-side and wind-side disturbances and models' sensitivity to parameter values. Discussed are phenomena observed in simulations and related concerns in regard to the

M. Y. Borodulin

2009-01-01

87

Hydraulics  

NSDL National Science Digital Library

These interactive learning objects, created by instructors from Fox Valley Technical College and other colleges in the Wisconsin Technical College program, focus on concepts that cover a broad-based electromechanical program. Here visitors will find learning objects in Hydraulics with over 25 lessons in Actuators, Relief Valves, Basic Concepts, and Directional Control Valves.

88

A next-generation modeling capability assesses wind turbine array fluid dynamics and aeroelastic simulations  

E-print Network

to and generating wake turbulence within Computational Fluid Dynamics (CFD) simulation of atmospheric boundary layer the impacts that upwind turbines have on turbines in their wake and give greater insight into overall wind turbines both reacting to and generating turbulence. NREL's research helps understand the impacts upstream

89

Numerical simulation of thermal-hydraulic generators running in a single regime  

NASA Astrophysics Data System (ADS)

The paper presents the basis for the design of thermal-hydraulic generators running in a single regime. The thermal-hydraulic generators in a single regime running represent an absolute novelty worldwide (a pioneer invention). Based on the methodology concerning this subject, the design calculus for an experimental model was developed.

Chioreanu, Nicolae; Mitran, Tudor; Rus, Alexandru; Beles, Horia

2014-06-01

90

Wind Turbines Condition Monitoring and Fault Diagnosis Using Generator Current Amplitude  

E-print Network

Wind Turbines Condition Monitoring and Fault Diagnosis Using Generator Current Amplitude cases. Index Terms--Wind turbine, DFIG, fault detection, diagnosis, amplitude modulation, Hilbert constitutes an essential background for the development of any failure diagnosis system. Regarding a failure

Paris-Sud XI, Université de

91

Preliminary design and viability consideration of external, shroud-based stators in wind turbine generators  

E-print Network

Horizontal-axis wind turbine designs often included gearboxes or large direct-drive generators to compensate for the low peripheral speeds of the turbine hub. To take advantage of high blade tip speeds, an alternative ...

Shoemaker-Trejo, Nathaniel (Nathaniel Joseph)

2012-01-01

92

Method for predicting impulsive noise generated by wind turbine rotors  

NASA Technical Reports Server (NTRS)

Large wind turbines can generate both broad band and impulsive noises. These noises can be controlled by proper choice of rotor design parameters such as rotor location with respect to the supporting tower, tower geometry and tip speed. A method was developed to calculate the impulsive noise generated when the wind turbine blade experiences air forces that are periodic functions of the rotational frequency. This phenomenon can occur when the blades operate in the wake of the support tower and the nonuniform velocity field near the ground due to wind shear. Results from this method were compared with measured sound spectra taken at locations of one to two rotor diameters from the DOE/NASA Mod-1 wind turbine. The calculated spectra generally agreed with the measured data in both the amplitude of the predominant harmonics and the roll of rate with frequency. Measured sound pressure levels far from the Mod-1 (15 rotor diameters), however, were higher than predicted. Simultaneous measurements in the near and far field indicated that the propagation effects could enhance the sound levels by more than 10 dB above that expected by spherical dispersion. These propagation effects are believed to be due to terrain and atmospheric characteristics of the Mod-1 site.

Viterna, L. A.

1982-01-01

93

Apparatus and methods of reheating gas turbine cooling steam and high pressure steam turbine exhaust in a combined cycle power generating system  

DOEpatents

In a combined cycle system having a multi-pressure heat recovery steam generator, a gas turbine and steam turbine, steam for cooling gas turbine components is supplied from the intermediate pressure section of the heat recovery steam generator supplemented by a portion of the steam exhausting from the HP section of the steam turbine, steam from the gas turbine cooling cycle and the exhaust from the HP section of the steam turbine are combined for flow through a reheat section of the HRSG. The reheated steam is supplied to the IP section inlet of the steam turbine. Thus, where gas turbine cooling steam temperature is lower than optimum, a net improvement in performance is achieved by flowing the cooling steam exhausting from the gas turbine and the exhaust steam from the high pressure section of the steam turbine in series through the reheater of the HRSG for applying steam at optimum temperature to the IP section of the steam turbine.

Tomlinson, Leroy Omar (Niskayuna, NY); Smith, Raub Warfield (Ballston Lake, NY)

2002-01-01

94

New life available for old Turbine/Generators and boilers  

SciTech Connect

Maintaining the integrity of power generation and supply with a very limited number of plant-capacity additions is the goal of the utility industry during the next 20 years. This goal can only be realized by careful operation and timely maintenance of existing generating capacity, thus conserving the availability of in-place equipment. Utilities are challenging their major suppliers to extend the design lives of existing equipment to 50 to 60 years without adversely affecting availability, as many fossil units are approaching the 35 to 40 year design limit of their original design lives. Leading boiler and turbine/generator manufacturers are equipped to undertake major modernization/rehabilitation programs for upgrading, uprating, and repowering steam generators, turbine/generators, and auxiliary equipment. This progam must be customized to the individual needs of a specific unit. Many units that are now operating at derated capacities can be restored to their original output, and often can produce 10% or more above their original design ratings with improved heat rates and overall efficiencies. 14 figures, 2 tables.

Friedlander, G.D.

1983-05-01

95

Variable Speed Wind Turbine Generator with Zero-sequence Filter  

DOEpatents

A variable speed wind turbine generator system to convert mechanical power into electrical power or energy and to recover the electrical power or energy in the form of three phase alternating current and return the power or energy to a utility or other load with single phase sinusoidal waveform at sixty (60) hertz and unity power factor includes an excitation controller for generating three phase commanded current, a generator, and a zero sequence filter. Each commanded current signal includes two components: a positive sequence variable frequency current signal to provide the balanced three phase excitation currents required in the stator windings of the generator to generate the rotating magnetic field needed to recover an optimum level of real power from the generator; and a zero frequency sixty (60) hertz current signal to allow the real power generated by the generator to be supplied to the utility. The positive sequence current signals are balanced three phase signals and are prevented from entering the utility by the zero sequence filter. The zero sequence current signals have zero phase displacement from each other and are prevented from entering the generator by the star connected stator windings. The zero sequence filter allows the zero sequence current signals to pass through to deliver power to the utility.

Muljadi, Eduard (Golden, CO)

1998-08-25

96

Variable speed wind turbine generator with zero-sequence filter  

DOEpatents

A variable speed wind turbine generator system to convert mechanical power into electrical power or energy and to recover the electrical power or energy in the form of three phase alternating current and return the power or energy to a utility or other load with single phase sinusoidal waveform at sixty (60) hertz and unity power factor includes an excitation controller for generating three phase commanded current, a generator, and a zero sequence filter. Each commanded current signal includes two components: a positive sequence variable frequency current signal to provide the balanced three phase excitation currents required in the stator windings of the generator to generate the rotating magnetic field needed to recover an optimum level of real power from the generator; and a zero frequency sixty (60) hertz current signal to allow the real power generated by the generator to be supplied to the utility. The positive sequence current signals are balanced three phase signals and are prevented from entering the utility by the zero sequence filter. The zero sequence current signals have zero phase displacement from each other and are prevented from entering the generator by the star connected stator windings. The zero sequence filter allows the zero sequence current signals to pass through to deliver power to the utility.

Muljadi, Eduard (Golden, CO)

1998-01-01

97

Variable speed wind turbine generator with zero-sequence filter  

DOEpatents

A variable speed wind turbine generator system to convert mechanical power into electrical power or energy and to recover the electrical power or energy in the form of three phase alternating current and return the power or energy to a utility or other load with single phase sinusoidal waveform at sixty (60) hertz and unity power factor includes an excitation controller for generating three phase commanded current, a generator, and a zero sequence filter. Each commanded current signal includes two components: a positive sequence variable frequency current signal to provide the balanced three phase excitation currents required in the stator windings of the generator to generate the rotating magnetic field needed to recover an optimum level of real power from the generator; and a zero frequency sixty (60) hertz current signal to allow the real power generated by the generator to be supplied to the utility. The positive sequence current signals are balanced three phase signals and are prevented from entering the utility by the zero sequence filter. The zero sequence current signals have zero phase displacement from each other and are prevented from entering the generator by the star connected stator windings. The zero sequence filter allows the zero sequence current signals to pass through to deliver power to the utility. 14 figs.

Muljadi, E.

1998-08-25

98

Method for repairing a steam turbine or generator rotor  

SciTech Connect

A method is described for repairing low alloy steel steam turbine or generator rotors, the method comprising: a. machining mating attachments on a replacement end and a remaining portion of the original rotor; b. mating the replacement end and the original rotor; c. welding the replacement end to the original rotor by narrow-gap gas metal arc or submerged arc welding up to a depth of 1/2-2 inches from the rotor surface; d. gas tungsten arc welding the remaining 1/2-2 inches; e. boring out the mating attachment and at least the inside 1/4 inch of the welding; and f. inspecting the bore.

Clark, R.E.; Amos, D.R.

1987-01-06

99

Utility experience with two demonstration wind turbine generators  

NASA Technical Reports Server (NTRS)

Edison has committed 360 MW of nameplate generating capacity to wind energy by year 1990 in its long-range generation plan. To reach this goal the Company's wind energy program focuses on three areas: the continuous evaluation of the wind resource, the hands-on demonstration of wind turbine generators (WTG) and an association with wind park developers. Two demonstration WTGs have been installed and operated at Edison's Wind Energy Center near Palm Springs, California: a 3 MW horizontal axis Bendix/Schachle WTG and a 500 kW vertical axis Alcoa WTG. They are part of a one to two year test program during which the performance of the WTGs will be evaluated, their system operation and environmental impact will be assessed and the design criteria of future WTGs will be identified. Edison's experience with these two WTGs is summarized and the problems encountered with the operation of the two machines are discussed.

Wehrey, M. C.

1982-01-01

100

Microfabricated rankine cycle steam turbine for power generation and methods of making the same  

NASA Technical Reports Server (NTRS)

In accordance with the present invention, an integrated micro steam turbine power plant on-a-chip has been provided. The integrated micro steam turbine power plant on-a-chip of the present invention comprises a miniature electric power generation system fabricated using silicon microfabrication technology and lithographic patterning. The present invention converts heat to electricity by implementing a thermodynamic power cycle on a chip. The steam turbine power plant on-a-chip generally comprises a turbine, a pump, an electric generator, an evaporator, and a condenser. The turbine is formed by a rotatable, disk-shaped rotor having a plurality of rotor blades disposed thereon and a plurality of stator blades. The plurality of stator blades are interdigitated with the plurality of rotor blades to form the turbine. The generator is driven by the turbine and converts mechanical energy into electrical energy.

Frechette, Luc (Inventor); Muller, Norbert (Inventor); Lee, Changgu (Inventor)

2009-01-01

101

Stabilization of Wind Turbine Generator System by STATCOM  

NASA Astrophysics Data System (ADS)

Recently voltage-source or current-source inverter based various FACTS devices have been used for flexible power flow control, secure loading, damping of power system oscillation and even for the stabilization of wind energy generation. In this paper, we propose the static synchronous compensator (STATCOM) based on voltage source converter (VSC) PWM technique to stabilize grid connected wind generator system. A simple control strategy of STATCOM is adopted where only measurement of rms voltage at the wind generator terminal is needed. Fuzzy logic controller rather than conventional PI controller is proposed as the control methodology of STATCOM. Multi-mass shaft model of wind turbine generator system (WTGS) is also considered as shaft modeling has a big influence on the transient performance of WTGS. Transient performance of STATCOM connected WTGS is compared also with that of pitch controlled WTGS. Both symmetrical and unsymmetrical faults are analyzed. Moreover, the steady state performance of STATCOM connected WTGS is analyzed. It is reported that STATCOM can reduce the voltage fluctuation significantly. Finally STATCOM is applied to a wind park model with multiple wind generators. Comprehensive results are presented to assess the performance of STATCOM connected WTGS, where the simulations have been done by PSCAD/EMTDC.

Muyeen, S. M.; Mannan, Mohammad Abdul; Ali, Mohd. Hasan; Takahashi, Rion; Murata, Toshiaki; Tamura, Junji

102

A doubly-fed permanent magnet generator for wind turbines  

E-print Network

Optimum extraction of energy from a wind turbine requires that turbine speed vary with wind speed. Existing solutions to produce constant-frequency electrical output under windspeed variations are undesirable due to ...

Thomas, Andrew J. (Andrew Joseph), 1981-

2004-01-01

103

Influence of Hydraulic Design on Stability and on Pressure Pulsations in Francis Turbines at Overload, Part Load and Deep Part Load based on Numerical Simulations and Experimental Model Test Results  

NASA Astrophysics Data System (ADS)

Francis turbines have been running more and more frequently in part load conditions, in order to satisfy the new market requirements for more dynamic and flexible energy generation, ancillary services and grid regulation. The turbines should be able to be operated for longer durations with flows below the optimum point, going from part load to deep part load and even speed-no-load. These operating conditions are characterised by important unsteady flow phenomena taking place at the draft tube cone and in the runner channels, in the respective cases of part load and deep part load. The current expectations are that new Francis turbines present appropriate hydraulic stability and moderate pressure pulsations at overload, part load, deep part load and speed-no-load with high efficiency levels at normal operating range. This study presents series of investigations performed by Voith Hydro with the objective to improve the hydraulic stability of Francis turbines at overload, part load and deep part load, reduce pressure pulsations and enlarge the know-how about the transient fluid flow through the turbine at these challenging conditions. Model test measurements showed that distinct runner designs were able to influence the pressure pulsation level in the machine. Extensive experimental investigations focused on the runner deflector geometry, on runner features and how they could reduce the pressure oscillation level. The impact of design variants and machine configurations on the vortex rope at the draft tube cone at overload and part load and on the runner channel vortex at deep part load were experimentally observed and evaluated based on the measured pressure pulsation amplitudes. Numerical investigations were employed for improving the understanding of such dynamic fluid flow effects. As example for the design and experimental investigations, model test observations and pressure pulsation curves for Francis machines in mid specific speed range, around nqopt = 50 min?1 are reported, analysed and commented here. The analysis of experimental results allowed the identification of designs and configurations, which can improve the machine stability.

Magnoli, M. V.; Maiwald, M.

2014-12-01

104

Analysis of the electrical characteristics of a Westinghouse variable speed generating system for wind turbine applications  

Microsoft Academic Search

Variable speed electric generating technology can enhance the general use of wind energy in electric utility applications. This enhancement results from two characteristic properties of variable speed wind turbine generators: an improvement in drive train damping characteristics, which results in reduced structural loading on the entire wind turbine system, and an improvement in the overall efficiency by using a more

J. I. Herrera; T. W. Reddoch

1988-01-01

105

Mod-5A wind turbine generator program design report. Volume 4: Drawings and specifications, book 5  

NASA Technical Reports Server (NTRS)

The design, development and analysis of the 7.3 MW MOD-5A wind turbine generator is documented. There are four volumes. This volume contains the drawings and specifications that were developed in preparation for building the MOD-5A wind turbine generator. Detail drawings of several assemblies and subassemblies are given. This is the fifth book of volume 4.

1984-01-01

106

Wind turbine generator interaction with diesel generators on an isolated power system  

NASA Technical Reports Server (NTRS)

The results of a dynamic interaction investigation to characterize any disturbances caused by interfacing the Mod 0A wind turbine (150 kW configuration) with the Block Island utility diesel generator grid are reported. The tests were run when only two diesel generators were on line, and attention was given to power, frequency, and voltage time profiles. The interconnected system was examined in the start-up and synchronization phase, normal shutdown and cut-out of the wind turbine, during fixed pitch generation, and during variable pitch operation. Governors were installed on the diesel generators to accommodate the presence of wind-derived electricity. The blade pitch control was set to maintain power at 150 kW or below. Power and voltage transients were insignificant during start-up and shutdown, and frequency aberrations were within the range caused by load fluctuations. It is concluded that wind turbine generation can be successfully implemented by an isolated utility, even with a significant penetration to the total grid output.

Scott, G. W.; Wilreker, V. F.; Shaltens, R. K.

1983-01-01

107

Removal of Dioxin Contamination for Gas Turbine Generator Set Repair  

SciTech Connect

Decontamination projects are typically undertaken in the interest of reducing disposal costs. This goal can be achieved because decontamination concentrates the contaminant into a smaller volume or changes its form so that a lower cost disposal technology becomes available. Less frequently, decontamination adds value back to the fouled structure or contaminated piece of equipment. This removal of dioxins from a gas turbine generator set is one of the latter cases. A multi-million dollar piece of equipment could have been destined for the scrap pile. Instead, an innovative, non-destructive decontamination technology, developed under EPA and DOE demonstration programs has was employed so that the set could repaired and put back into service. The TechXtractchemical decontamination technology reduced surface dioxin / furan concentrations from as high as 24,000 ng / m2 to less than 25 ng / m2 and below detection limits.

Fay, W. S.; Borah, R.E.

2003-02-25

108

Designing Drive Trains for the Next Generation of Wind Turbines (FloDesign Wind Turbine Corporation)  

Microsoft Academic Search

Today's wind turbines have nearly reached their maximum possible efficiency and are limited to sites with a narrow profile of wind patterns. The patent-pending Mixer Ejector Wind Turbine (MEWT) concept proposed by FloDesign promises to outperform existing wind turbines by a factor of three or more in a much wider range of wind resources. Olin College’s FloDesign SCOPE team was

Mateen Abdul; Kelcy Adamec; Gavin Boggs; Matthew Crawford; Kevin Sihlanick; Russell Torres

2009-01-01

109

Thermal, Hydraulic, and Corrosion Aspects of PWR Steam Generator Problems  

Microsoft Academic Search

Two types of PWR steam generators are in use: recirculating steam generators (RSGs) and once-through steam generators (OTSGs). Most of the units and vertical and this review will be limited to vertical units. Some of these steam generators have operated with a minimum of problems while other steam generator designs have experienced a variety of corrosion and mechanically induced problems.

STANLEY J. GREEN

1988-01-01

110

Prediction of pressure fluctuation of a hydraulic turbine at no-load condition  

NASA Astrophysics Data System (ADS)

In order to study characteristics of pressure fluctuation of a turbine during the starting period, a turbine with guide vanes device at no-load condition was investigated using RNG k-epsilon turbulence model. The inner flow distribution and pressure fluctuation characteristics were analyzed. Results show that the pressure fluctuations in the region between the runner and guide vanes are different around the runner inlet. The dominant frequency of pressure fluctuation in the vaneless space close to the casing outlet is the blade passing frequency, while the dominant frequency at the rest region is the twice of the blade passing frequency. The increase of amplitude of pressure fluctuation close to the casing outlet can be attribute to the large scale stall at suction side of the runner inlet.

Chen, T. J.; Wu, X. J.; Liu, J. T.; Wu, Y. L.

2015-01-01

111

Operational-Condition-Independent Criteria Dedicated to Monitoring Wind Turbine Generators: Preprint  

SciTech Connect

To date the existing wind turbine condition monitoring technologies and commercially available systems have not been fully accepted for improving wind turbine availability and reducing their operation and maintenance costs. One of the main reasons is that wind turbines are subject to constantly varying loads and operate at variable rotational speeds. As a consequence, the influences of turbine faults and the effects of varying load and speed are coupled together in wind turbine condition monitoring signals. So, there is an urgent need to either introduce some operational condition de-coupling procedures into the current wind turbine condition monitoring techniques or develop a new operational condition independent wind turbine condition monitoring technique to maintain high turbine availability and achieve the expected economic benefits from wind. The purpose of this paper is to develop such a technique. In the paper, three operational condition independent criteria are developed dedicated for monitoring the operation and health condition of wind turbine generators. All proposed criteria have been tested through both simulated and practical experiments. The experiments have shown that these criteria provide a solution for detecting both mechanical and electrical faults occurring in wind turbine generators.

Yang, W.; Sheng, S.; Court, R.

2012-08-01

112

Turbine Airfoil Aerothermal Characteristics in Future Coal-Gas Based Power Generation Systems  

Microsoft Academic Search

Future advanced turbine systems for electric power generation systems, based on coal-gasified fuels with CO2 capture and sequestration, are aimed for achieving higher cycle efficiency and near-zero emission. Most promising operating cycles being developed are hydrogen-fired cycle and oxy-fuel cycle. Both cycles will likely have turbine working fluids significantly different from that of conventional air-based gas turbines. The oxy-fuel cycle,

Minking K. Chyu; Mary Anne Alvin

113

Control and stabilization of the DOE/NASA Mod-1 two megawatt wind turbine generator  

NASA Technical Reports Server (NTRS)

This paper describes the controls design, performance simulation process and specialized dynamic considerations for the DOE/NASA Mod 1 wind turbine generator (WTG). It shows controls, structural and utility interface considerations of the wind turbine generator and shows how a wind turbine generator can be integrated with a synchronous power system. Differences with respect to fossil or hydro generation and their implications are vital to long-term WTG reliability and availability and acceptance by utilities and consumers. The paper describes the control performance requirements to provide stable pitch and excitation control with drivetrain torsional dynamics, and the control of power swing stability and utility feeder voltage due to wind gusts.

Barton, R. S.; Bowler, C. E. J.; Piwko, R. J.

1979-01-01

114

A circulation system with low boiling point medium to replace water-cooling medium for turbine generator stator  

Microsoft Academic Search

In this article, an evaporative cooling circulation system for turbine generator stator winding was introduced. The design has taken into account of the characteristics of the whole liquid cooling approach for the large turbine generator, the requirements for the 50MW turbine generator evaporative cooling for the stator as well as the physical and chemical characteristics of the low boiling point

Fu De Ping; Guo Jian Hong; Li Zhen Guo; Xiong Bin; Dong Hai Hong; Gu Guo Biao

2010-01-01

115

Sound measurements of the MOD-2 wind turbine generator  

NASA Technical Reports Server (NTRS)

Sound measurements were made for the MOD-2 wind turbine generator for wind conditions of 7.6 to 13.4 m/sec and for output power ratings of about 1 to 2 NW. Both broad band and narrow band data wre obtained for a range of distances and azimuth angles from the machine. The rotor sound spectra are random in character and peak in the frequency ranges 30 to 50 Hz and 800 to 1300 Hz. Both peaks are predictable from experience with helicopter rotors and propellers. Results suggest that the lower frequency peak is due to the effects of inflow turbulence and the higher frequency peak is due to the interactions of the turbulent boundary layers with the trailing edges of the blades. The boundary layer related sound is the dominant component in the audible frequency range and determines the detectability of the machine. It could be detected at a distance of 1350 m in the upwind direction where the background noise was 30 dB (A) and at distances in excess of 2100 m in the downwind direction. Discrete frequency sound components associated with the power generation equipment are measurable in the direction normal to the axis of rotation but are not believed to be significant for detection or community response.

Hubbard, H. H.; Shepherd, K. P.; Grosveld, F. W.

1981-01-01

116

Wind Turbine Generator System Duration Test Report for the Mariah Power Windspire Wind Turbine  

SciTech Connect

This test was conducted as part of the U.S. Department of Energy's (DOE) Independent Testing project to help reduce the barriers of wind energy expansion by providing independent testing results for small turbines. In total, five turbines are being tested at the National Wind Technology Center (NWTC) as a part of the first round of this project. Duration testing is one of up to five tests that may be performed on the turbines. Other tests include power performance, safety and function, noise, and power quality tests. NWTC testing results provide manufacturers with reports that may be used to meet part of small wind turbine certification requirements. This duration test report focuses on the Mariah Power Windspire wind turbine.

Huskey, A.; Bowen, A.; Jager, D.

2010-05-01

117

Doubly Fed Induction Generator Wind Turbines with Fuzzy Controller: A Survey  

PubMed Central

Wind energy is one of the extraordinary sources of renewable energy due to its clean character and free availability. With the increasing wind power penetration, the wind farms are directly influencing the power systems. The majority of wind farms are using variable speed wind turbines equipped with doubly fed induction generators (DFIG) due to their advantages over other wind turbine generators (WTGs). Therefore, the analysis of wind power dynamics with the DFIG wind turbines has become a very important research issue, especially during transient faults. This paper presents fuzzy logic control of doubly fed induction generator (DFIG) wind turbine in a sample power system. Fuzzy logic controller is applied to rotor side converter for active power control and voltage regulation of wind turbine. PMID:25028677

Sathiyanarayanan, J. S.; Senthil Kumar, A.

2014-01-01

118

An Experimental Study on the Darrieus-Savonius Turbine for the Tidal Current Power Generation  

Microsoft Academic Search

The Darrieus turbine is popular for tidal current power generation in Japan. It is simple in structure with straight wings rotating around a vertical axis, so that it has no directionality against the motion of tidal flow which changes its direction twice a day. However, there is one defect in the Darrieus turbine; its small starting torque. Once it stops,

Yusaku Kyozuka

2008-01-01

119

Development of an axial microturbine for a portable gas turbine generator  

NASA Astrophysics Data System (ADS)

A miniature gas turbine is under development with the aim of generating electrical energy from fuel. This system consists of a compressor, combustion chamber, turbine and generator. The turbine is a single-stage axial impulse turbine (Laval turbine) with a rotor diameter of 10 mm, made of stainless steel using die-sinking electro-discharge machining. It has been tested with compressed air to speeds up to 160 000 rpm and generates a maximum mechanical power of 28 W with an efficiency of 18.4%. When coupled to a small generator, it generates 16 W of electrical power, which corresponds to an efficiency for the total system of 10.5%. The power density is mainly limited by the maximal speed of the ball bearings. The main losses are the blade profile losses and the exit losses. Higher speeds can considerably reduce the exit losses and therefore increase efficiency and power density. An improved turbine has been tested at temperatures up to 360 °C and generates up to 44 W of electrical energy with a total efficiency of 16%. A 20 mm diameter centrifugal compressor matching the pressure and flow characteristics of the turbine has been designed and is currently under construction.

Peirs, Jan; Reynaerts, Dominiek; Verplaetsen, Filip

2003-07-01

120

Signature management of radar returns from wind turbine generators  

NASA Astrophysics Data System (ADS)

The large radar cross section of wind turbine generator (WTG) blades combined with high tip speeds can produce significant Doppler returns when illuminated by a radar. Normally, an air traffic control radar system will filter out large returns from stationary targets, but the Doppler shifts introduced by the WTG blades are interpreted as moving aircraft that can confuse radar operators and compromise safety. A possible solution to this problem is to incorporate an active layer into the structure of the WTG blades that can be used to dynamically modulate the radar cross section (RCS) of the blade return. The active blade can operate in one of two modes: first the blade RCS can be modulated to provide a Doppler return that is outside the detectable range of the radar receiver system so that it is rejected; a second mode of operation is to introduce specific coding onto the Doppler returns so that they may be uniquely identified and rejected. The active layer used in the system consists of a frequency selective surface controlled by semiconductor diodes and is a development of techniques developed for active radar absorbers. Results of theoretical and experimental work using a 10 GHz Doppler radar and scale-model WTG are presented.

Tennant, A.; Chambers, B.

2006-04-01

121

Numerical prediction for effects of guide vane blade numbers on hydraulic turbine performance  

NASA Astrophysics Data System (ADS)

Using unstructured hybrid grid technique and SIMPLEC algorithm,a general three-dimensional simulation based on Reynolds Navier- stocks in multiple reference frames and the RNG k-? turbulence model, is presented for the reversal centrifugal pump (PAT) with a guide vane. Four different schemes are designed by a change of the number of guide vane blade of PAT. The inner flow field in every scheme is simulated, accordingly, the external characteristic and static pressure distribution in flow field in PAT is obtained. The results obtained show that the efficiency can be improved by adding a guide vane for the PAT, besides, the high efficiency area is wider than before. Guide blade numbers changed, external characteristics of turbine changed, and the external characteristic changed. The optimal value is existent for the guide vane blade number, which has a great impact on the distribution of pressure in runner inlet.

Shi, F. X.; Yang, J. H.; Wang, X. H.; Li, C. E.

2013-12-01

122

Thermal, hydraulic, and corrosion aspects of PWR steam generator problems  

SciTech Connect

Two types of PWR steam generators are in use: recirculating steam generators (RSGs) and once-through steam generators (OTSGs). Most of the units and vertical and this review will be limited to vertical units. Some of these steam generators have operated with a minimum of problems while other steam generator designs have experienced a variety of corrosion and mechanically induced problems. The discussion will focus more on the designs that have experienced problems and the effort expended to correct them. Corrosion problems include denting, wastage, intergranular attack, stress corrosion cracking, corrosion fatigue, pitting on the outside surfaces of the tubes, and stress corrosion cracking the inner surfaces of the tubes. Mechanical concerns have included water hammer, thermal stratification in feed-water pipes, fretting and wear of the tubes caused by excessive tube vibration, and erosion-corrosion. These problems have caused unscheduled outages and expensive repairs.

Green, S.J.

1988-01-01

123

CFD Analysis for the Performance of Cross-Flow Hydraulic Turbine with the Variation of Blade Angle  

Microsoft Academic Search

The purpose of this study is both to further optimize the structure of cross-flow turbine and to improve the turbine performance. Optimization of the turbine structure has been made by the analysis of the turbine performance with the variation of the blade angle using a commercial CFD code. The results show that inlet and outlet angles of the runner blade

Y. D. Choi; J.. I. Lim; C. G. Kim; Y. T. Kim; Y. H. Lee

2009-01-01

124

Implementation of a Two-Axis Servo-Hydraulic System for Full-Scale Fatigue Testing of Wind Turbine Blades  

SciTech Connect

Recently, the blade fatigue testing capabilities at NREL were upgraded from single-axis to two-axis loading. To implement this, several practical challenges were addressed, as hardware complexity increased dramatically with two actuators applying the loads at right angles to each other. A custom bellcrank was designed and implemented to minimize the load angle errors and to prevent actuator side loading. The control system was upgraded to accept load and displacement feedback from two actuators. The inherent long strokes uniquely associated with wind turbine blade-tests required substantial real-time corrections for both the control and data systems. A custom data acquisition and control system was developed using a National Instruments LabVIEW platform that interfaces with proprietary servo-hydraulic software developed by MTS Corporation. Before testing, the program is run under quasi-static (slow speed) conditions and iterates to determine the correct operational control parameters for the controller, taking into consideration geometry, test speed, and phase angle errors between the two actuators. Comparisons are made between single-axis and two-axis test loads using actual test load data and load uncertainties are qualitatively described. To date, two fatigue tests have been completed and another is currently ongoing using NREL's two-axis capability.

Hughes, S. D.; Musial, W. D. [National Renewable Energy Lab., Golden, CO (US); Stensland, T. [Stensland Technologies (US)

1999-09-09

125

Parallel operation of wind turbine, fuel cell, and diesel generation sources  

Microsoft Academic Search

We investigated a small isolated hybrid power system that used a parallel combination of dispatchable and nondispatchable power generation sources. The nondispatchable generation came from a nature-dependent wind turbine, and the dispatchable generations were a fuel cell and a diesel generator. On the load side, the nondispatchable portion was the village load, and the dispatchable portion was the energy storage,

E. Muljadi; C. Wang; M. H. Nehrir

2004-01-01

126

A market and engineering study of a 3-kilowatt class gas turbine generator  

E-print Network

Market and engineering studies were performed for the world's only commercially available 3 kW class gas turbine generator, the IHI Aerospace Dynajet. The objectives of the market study were to determine the competitive ...

Monroe, Mark A. (Mark Alan)

2003-01-01

127

48. DETAIL INTERIOR VIEW OF ACTUATOR TANKS BETWEEN TURBINE/GENERATOR UNITS ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

48. DETAIL INTERIOR VIEW OF ACTUATOR TANKS BETWEEN TURBINE/GENERATOR UNITS NO 1 AND NO 2 ON LEVEL +37 OF POWERHOUSE #1. - Bonneville Project, Powerhouse No.1, Spanning Bradford Slough, from Bradford Island, Bonneville, Multnomah County, OR

128

Large wind turbine generators. [NASA program status and potential costs  

NASA Technical Reports Server (NTRS)

The large wind turbine portion of the Federal Wind Energy Program consists of two major project efforts: (1) the Mod-0 test bed project for supporting research technology, and (2) the large experimental wind turbines for electric utility applications. The Mod-0 has met its primary objective of providing the entire wind energy program with early operations and performance data. The large experimental wind turbines to be tested in utility applications include three of the Mod-0A (200 kW) type, one Mod-1 (2000 kW), and possibly several of the Mod-2 (2500 kW) designs. This paper presents a description of these wind turbine systems, their programmatic status, and a summary of their potential costs.

Thomas, R. L.; Donovon, R. M.

1978-01-01

129

Superconducting generators for large off shore wind turbines   

E-print Network

This thesis describes four novel superconducting machine concepts, in the pursuit of finding a suitable design for large offshore wind turbines. The designs should be reliable, modular and light-weight. The main novelty ...

Keysan, Ozan

2014-06-30

130

An Experimental Study on the Darrieus-Savonius Turbine for the Tidal Current Power Generation  

NASA Astrophysics Data System (ADS)

The Darrieus turbine is popular for tidal current power generation in Japan. It is simple in structure with straight wings rotating around a vertical axis, so that it has no directionality against the motion of tidal flow which changes its direction twice a day. However, there is one defect in the Darrieus turbine; its small starting torque. Once it stops, a Darrieus turbine is hard to re-start until a fairly fast current is exerted on it. To improve the starting torque of the Darrieus turbine used for tidal power generation, a hybrid turbine, composed of a Darrieus turbine and a Savonius rotor is proposed. Hydrodynamic characteristics of a semi-circular section used for the Savonius bucket were measured in a wind tunnel. The torque of a two bucket Savonius rotor was measured in a circulating water channel, where four different configurations of the bucket were compared. A combined Darrieus and Savonius turbine was tested in the circulating water channel, where the effect of the attaching angle between Darrieus wing and Savonius rotor was studied. Finally, power generation experiments using a 48 pole electric generator were conducted in a towing tank and the power coefficients were compared with the results of experiments obtained in the circulating water channel.

Kyozuka, Yusaku

131

Predictive control of a chaotic permanent magnet synchronous generator in a wind turbine system  

NASA Astrophysics Data System (ADS)

This paper investigates how to address the chaos problem in a permanent magnet synchronous generator (PMSG) in a wind turbine system. Predictive control approach is proposed to suppress chaotic behavior and make operating stable; the advantage of this method is that it can only be applied to one state of the wind turbine system. The use of the genetic algorithms to estimate the optimal parameter values of the wind turbine leads to maximization of the power generation. Moreover, some simulation results are included to visualize the effectiveness and robustness of the proposed method. Project supported by the CMEP-TASSILI Project (Grant No. 14MDU920).

Manal, Messadi; Adel, Mellit; Karim, Kemih; Malek, Ghanes

2015-01-01

132

WTG Energy Systems' MP1-200 200 kilowatt wind turbine generator. [a fixed pitch rotor configuration driving a synchronous generator  

NASA Technical Reports Server (NTRS)

The preliminary design criteria of the MP1-200 wind turbine are given along with a brief description of the wind turbine generator. Performance and operational experience and cost factors are included. Recommendations for additional research are listed.

Spaulding, A. P., Jr.

1979-01-01

133

Slip power recovery induction generators for large vertical axis wind turbines  

Microsoft Academic Search

Simulation results are presented for the performance of a slip power recovery induction generator coupled to a vertical-axis wind turbine. The suitability of this type of generator for wind-driven applications is discussed. A qualitative comparison with two other alternatives is made, highlighting the basic features of the generator configuration studied. Quantitative simulation analysis showed that it is possible to reduce

H. L. Nakra; B. Dube

1988-01-01

134

Wind Turbine Bearing Failure Detection Using Generator Stator Current Homopolar Component  

E-print Network

Wind Turbine Bearing Failure Detection Using Generator Stator Current Homopolar Component Ensemble detection of the generator health degeneration, facilitating a proactive response, minimizing downtime on the homopolar component of the generator stator current and attempts to highlight the use of the Ensemble

Paris-Sud XI, Université de

135

Design of a wind turbine-generator system considering the conformability to wind velocity fluctuations  

SciTech Connect

The conformability of the rated power output of the wind turbine-generator system and of the wind turbine type to wind velocity fluctuations are investigated with a simulation model. The authors examine three types of wind turbines: the Darrieus-Savonius hybrid, the Darrieus proper and the Propeller. These systems are mainly operated at a constant tip speed ratio, which refers to a maximum power coefficient points. As a computed result of the net extracting power, the Darrieus turbine proper has little conformability to wind velocity fluctuations because of its output characteristics. As for the other turbines, large-scale systems do not always have an advantage over small-scale systems as the effect of its dynamic characteristics. Furthermore, it is confirmed that the net extracting power of the Propeller turbine, under wind direction fluctuation, is much reduced when compared with the hybrid wind turbine. Thus, the authors conclude that the appropriate rated power output of the system exists with relation to the wind turbine type for each wind condition.

Wakui, Tetsuya; Hashizume, Takumi; Outa, Eisuke

1999-07-01

136

Closed-cycle gas turbines for power generation and LNG vaporization  

NASA Astrophysics Data System (ADS)

Cooling by LNG (liquefied nitrogen gas) in closed-cycle gas turbines results in double the electrical output of water cooled turbines. A circuit scheme of the LNG turbine is presented with the temperatures and pressures of the cycle. The turbine inlet temperature is limited to 720 C. Pressure level control and bypass control are the two basic types of control applied. The power station has an output of 4 x 100 MW, with four heaters arranged in series. The basic design of the heater, turbine, compressor, recuperator, and vaporizer is given. A cost comparison is made between the closed cycle gas turbine and steam turbine power stations with open rack vaporizer, submerged combustion vaporizer, or both. Using an LNG terminal with a closed-cycle gas turbine for the generation of electric power and LNG vaporization would mean a potential world-wide saving of 2,350 MW thermal power or 4.2 x 10(6) kg of LNG/day by 1985.

Weber, D.

1980-09-01

137

Comparative Assessment of Direct Drive High Temperature Superconducting Generators in Multi-Megawatt Class Wind Turbines  

SciTech Connect

This paper summarizes the work completed under the CRADA between NREL and American Superconductor (AMSC). The CRADA combined NREL and AMSC resources to benchmark high temperature superconducting direct drive (HTSDD) generator technology by integrating the technologies into a conceptual wind turbine design, and comparing the design to geared drive and permanent magnet direct drive (PMDD) wind turbine configurations. Analysis was accomplished by upgrading the NREL Wind Turbine Design Cost and Scaling Model to represent geared and PMDD turbines at machine ratings up to 10 MW and then comparing cost and mass figures of AMSC's HTSDD wind turbine designs to theoretical geared and PMDD turbine designs at 3.1, 6, and 10 MW sizes. Based on the cost and performance data supplied by AMSC, HTSDD technology has good potential to compete successfully as an alternative technology to PMDD and geared technology turbines in the multi megawatt classes. In addition, data suggests the economics of HTSDD turbines improve with increasing size, although several uncertainties remain for all machines in the 6 to 10 MW class.

Maples, B.; Hand, M.; Musial, W.

2010-10-01

138

Analysis of the electrical characteristics of a Westinghouse variable speed generating system for wind turbine applications  

NASA Astrophysics Data System (ADS)

Variable speed electric generating technology can enhance the general use of wind energy in electric utility applications. This enhancement results from two characteristic properties of variable speed wind turbine generators: an improvement in drive train damping characteristics, which results in reduced structural loading on the entire wind turbine system, and an improvement in the overall efficiency by using a more sophisticated electrical generator. Electronic converter systems are the focus of this investigation, particularly the properties of a Westinghouse variable-speed, constant-frequency system with wound-rotor induction generator and a cycloconverter. Experience with solid-state converter systems in large wind turbines is extremely limited. This report presents measurements of electrical performances of the Westinghouse system and is limited to the terminal characteristics of the system. Variable speed generating systems working effectively in utility applications will require a satisfactory interface between the turbine-generator pair and the utility network. The electrical testing described herein focuses largely on the interface characteristics of the generating system. A MOD-0 wind turbine was connected to a very strong system; thus, the voltage distortion was low and the total harmonic distortion in the utility voltage was less than 3 percent (within the 5 percent limit required by most utilities). The largest voltage component of a frequency below 60 Hz was 40 dB down from the 60-Hz component.

Herrera, J. I.; Reddoch, T. W.

1988-02-01

139

Pumps as turbines for low cost micro hydro power  

Microsoft Academic Search

Small centrifugal pumps are suitable for use as hydraulic turbines and have the advantage of being mass produced in many countries throughout the world. When used with an integral induction motor, they can be installed as a combined turbine and generator unit. Recent research and development work carried out at Nottingham Trent University in collaboration with the Intermediate Technology Development

A. A. Williams

1996-01-01

140

Statistical Safety Evaluation of BWR Turbine Trip Scenario Using Coupled Neutron Kinetics and Thermal Hydraulics Analysis Code SKETCH-INS/TRACE5.0  

NASA Astrophysics Data System (ADS)

The Best Estimate Plus Uncertainty (BEPU) method has been prepared for the regulatory cross-check analysis at Japan Nuclear Energy Safety Organization (JNES) on base of the three-dimensional neutron-kinetics/thermal- hydraulics coupled code SKETCH-INS/TRACE5.0. In the preparation, TRACE5.0 is verified against the large-scale thermal-hydraulic tests carried out with NUPEC facility. These tests were focused on the pressure drop of steam-liquid two phase flow and void fraction distribution. From the comparison of the experimental data with other codes (RELAP5/MOD3.3 and TRAC-BF1), TRACE5.0 was judged better than other codes. It was confirmed that TRACE5.0 has high reliability for thermal hydraulics behavior and are used as a best-estimate code for the statistical safety evaluation. Next, the coupled code SKETCH-INS/TRACE5.0 was applied to turbine trip tests performed at the Peach Bottom-2 BWR4 Plant. The turbine trip event shows the rapid power peak due to the voids collapse with the pressure increase. The analyzed peak value of core power is better simulated than the previous version SKETCH-INS/TRAC-BF1. And the statistical safety evaluation using SKETCH-INS/TRACE5.0 was applied to the loss of load transient for examining the influence of the choice of sampling method.

Ichikawa, Ryoko; Masuhara, Yasuhiro; Kasahara, Fumio

141

Candidate wind turbine generator site: annual data summary, January 1981-December 1981  

SciTech Connect

Summarized hourly meteorological data for 34 candidate and wind turbine generator sites for calendar year 1981 are presented. These data are collected for the purpose of evaluating the wind energy potential at these sites and are used to assist in selection of potential sites for installation and testing of large wind turbines in electric utility systems. For each site, wind speed, direction, and distribution data are given in eight tables. Use of information from these tables, with information about specific wind turbines, should allow the user to estimate the potential for wind energy production at each site.

Sandusky, W.F.; Buck, J.W.; Renne, D.S.; Hadley, D.L.; Abbey, O.B.

1982-07-01

142

Advanced gas turbines: The choice for low-cost, environmentally superior electric power generation  

SciTech Connect

In July 1993, the US Department of Energy (DOE) initiated an ambitious 8-year program to advance state-of-the-art gas turbine technology for land-based electric power generation. The program, known as the Advanced Turbine System (ATS) Program, is a joint government/industry program with the objective to demonstrate advanced industrial and utility gas turbine systems by the year 2000. The goals of the ATS Program are to develop gas turbine systems capable of providing low-cost electric power, while maintaining environmental superiority over competing power generation options. A progress report on the ATS Program pertaining to program status at DOE will be presented and reviewed in this paper. The technical challenges, advanced critical technology requirements, and systems designs meeting the goals of the program will be described and discussed.

Zeh, C.M.

1996-08-01

143

Thermal analysis of a simple-cycle gas turbine in biogas power generation  

SciTech Connect

This paper investigates the technical feasibility of utilizing small simple-cycle gas turbines (25 kW to 125 kW) for biogas power generation through thermal analysis. A computer code, GTPower, was developed to evaluate the performance of small simple-cycle gas turbines specifically for biogas combustion. The 125 KW Solar Gas Turbine (Tital series) has been selected as the base case gas turbine for biogas combustion. After its design parameters and typical operating conditions were entered into GTPower for analysis, GTPower outputted expected values for the thermal efficiency and specific work. For a sensitivity analysis, the GTPower Model outputted the thermal efficiency and specific work. For a sensitivity analysis, the GTPower Model outputted the thermal efficiency and specific work profiles for various operating conditions encountered in biogas combustion. These results will assist future research projects in determining the type of combustion device most suitable for biogas power generation.

Yomogida, D.E. [California Energy Commission, Sacramento, CA (United States); Thinh, Ngo Dinh [California State Univ., Sacramento, CA (United States)

1995-09-01

144

Large wind turbines: A utility option for the generation of electricity  

NASA Technical Reports Server (NTRS)

The wind resource is such that wind energy generation has the potential to save 6-7 quads of energy nationally. Thus, the Federal Government is sponsoring and encouraging the development of cost effective and reliable wind turbines. One element of the Federal Wind Energy Programs, Large Horizontal Axis Wind Turbine Development, is managed by the NASA Lewis Research Center for the Department of Energy. There are several ongoing wind system development projects oriented primarily toward utility application within this program element. In addition, a comprehensive technology program supporting the wind turbine development projects is being conducted. An overview is presented of the NASA activities with emphasis on application of large wind turbines for generation of electricity by utility systems.

Robbins, W. H.; Thomas, R. L.; Baldwin, D. H.

1980-01-01

145

Evaluation of a wind turbine electric power generator  

NASA Astrophysics Data System (ADS)

A technical assessment of the aerodynamic performance of the wind wheel turbine (WWT) is reported. The potential of the WWT in utilizing wind as an alternate power source was evaluated. Scaling parameters were developed to predict the aerodynamic performance of WWT prototype sized to produce 3, 9, 30, and 100 kw outputs in a 6.7 m/sec wind.

Swim, W. B.

1981-10-01

146

Control of wind turbine generators connected to power systems  

NASA Technical Reports Server (NTRS)

A unique simulation model based on a Mode-O wind turbine is developed for simulating both speed and power control. An analytical representation for a wind turbine that employs blade pitch angle feedback control is presented, and a mathematical model is formulated. For Mode-O serving as a practical case study, results of a computer simulation of the model as applied to the problems of synchronization and dynamic stability are provided. It is shown that the speed and output of a wind turbine can be satisfactorily controlled within reasonable limits by employing the existing blade pitch control system under specified conditions. For power control, an additional excitation control is required so that the terminal voltage, output power factor, and armature current can be held within narrow limits. As a result, the variation of torque angle is limited even if speed control is not implemented simultaneously with power control. Design features of the ERDA/NASA 100-kW Mode-O wind turbine are included.

Hwang, H. H.; Mozeico, H. V.; Gilbert, L. J.

1978-01-01

147

Designing Micro Wind Turbines for Portable Power Generation Francois Hogan  

E-print Network

,000. This led to the choice of NACA-0009 for our airfoil. Figure 2: NACA-0009 Chord and twist Using simple fluid. Future effortsConclusion Figure 1: Optimal TSR of popular turbines Figure 3: Lift coefficient of NACA-0009 Where: R=Total Radius B=Number of blades =Design Tip Speed Ratio Cl=Lift coefficient Where: R

Barthelat, Francois

148

An Experimental Study of Lightning Overvoltages in Wind Turbine Generation Systems  

NASA Astrophysics Data System (ADS)

In order to obtain good wind conditions, wind turbine generation systems are built at places like hill countries and shorefronts where few tall structures are found. However, this increases the risk of lightning strikes. To promote wind power generation, lightning-protection methodologies for such wind turbine generation systems have to be established. This paper presents the results of an experimental study which investigates the lightning overvoltages in wind turbine generation systems. The experiments were carried out on actual ground soil using a reduced-size wind turbine model with its foundations. From the experiments, the following conclusions have been deduced: (i) Voltage rise due to the grounding impedance of the foundations can cause a significant overvoltage between the tower foot and an incoming cable like a power, a communication or a control line. (ii) The voltage rise of the foundations and that of the surrounding ground soil may cause an overvoltage at the outermost insulation layer of an incoming cable, which can result in a breakdown or a deterioration of the insulation (iii) Voltage and current waveforms to understand the traveling-wave phenomenon on a wind power generation system with its foundations were obtained. The data will be useful for developing an EMTP simulation model of a wind turbine generation system for lightning overvoltage studies.

Yamamoto, Kazuo; Ohta, Tomokatsu; Noda, Taku; Yokoyama, Shigeru; Ametani, Akihiro

149

Application of multi-objective controller to optimal tuning of PID gains for a hydraulic turbine regulating system using adaptive grid particle swam optimization.  

PubMed

A hydraulic turbine regulating system (HTRS) is one of the most important components of hydropower plant, which plays a key role in maintaining safety, stability and economical operation of hydro-electrical installations. At present, the conventional PID controller is widely applied in the HTRS system for its practicability and robustness, and the primary problem with respect to this control law is how to optimally tune the parameters, i.e. the determination of PID controller gains for satisfactory performance. In this paper, a kind of multi-objective evolutionary algorithms, named adaptive grid particle swarm optimization (AGPSO) is applied to solve the PID gains tuning problem of the HTRS system. This newly AGPSO optimized method, which differs from a traditional one-single objective optimization method, is designed to take care of settling time and overshoot level simultaneously, in which a set of non-inferior alternatives solutions (i.e. Pareto solution) is generated. Furthermore, a fuzzy-based membership value assignment method is employed to choose the best compromise solution from the obtained Pareto set. An illustrative example associated with the best compromise solution for parameter tuning of the nonlinear HTRS system is introduced to verify the feasibility and the effectiveness of the proposed AGPSO-based optimization approach, as compared with two another prominent multi-objective algorithms, i.e. Non-dominated Sorting Genetic Algorithm II (NSGAII) and Strength Pareto Evolutionary Algorithm II (SPEAII), for the quality and diversity of obtained Pareto solutions set. Consequently, simulation results show that this AGPSO optimized approach outperforms than compared methods with higher efficiency and better quality no matter whether the HTRS system works under unload or load conditions. PMID:25481821

Chen, Zhihuan; Yuan, Yanbin; Yuan, Xiaohui; Huang, Yuehua; Li, Xianshan; Li, Wenwu

2014-12-01

150

Basic Study on Loss Reduction Effect by Stator-Teeth Slits in Turbine Generators  

NASA Astrophysics Data System (ADS)

In this study, we investigate the loss reduction effect by stator-teeth slits in turbine generators on the basis of electromagnetic field analysis and basic experiments. First, the loss reduction effect in the generator is estimated by the 3-D finite element method and the theoretical solution of eddy current loss. Next, an experiment using a simple model that simulates the stator-core ends of the turbine generator is carried out. It is clarified that the loss reduction effect by the slits depends on the frequency, flux density, and permeability of the stator teeth because the loss reduction effect weakens with the skin effect.

Yamazaki, Katsumi; Nishioka, Kazuyoshi; Nakahara, Akihito; Furukawa, Yoko; Takahashi, Kazuhiko; Yabumoto, Masao

151

Effects of turbulence on power generation for variable-speed wind turbines  

SciTech Connect

One of the primary advantages of variable-speed wind turbines over fixed-speed turbines should be improved aerodynamic efficiency. With variable-speed generation, in order to maintain a constant ratio of wind speed to tip speed, the wind turbine changes rotor speed as the wind speed changes. In this paper we compare a stall-controlled, variable-speed wind turbine to a fixed-speed turbine. The focus of this paper is to investigate the effects of variable speed on energy capture and its ability to control peak power. We also show the impact of turbulence on energy capture in moderate winds. In this report, we use a dynamic simulator to apply different winds to a wind turbine model. This model incorporates typical inertial and aerodynamic performance characteristics. From this study we found a control strategy that makes it possible to operate a stall-controlled turbine using variable speed to optimize energy capture and to control peak power. We also found that turbulence does not have a significant impact on energy capture.

Muljadi, E.; Butterfield, C.P.; Buhl, M.L. Jr.

1996-11-01

152

Operating experience feedback report -- turbine-generator overspeed protection systems: Commercial power reactors. Volume 11  

SciTech Connect

This report presents the results of the US Nuclear Regulatory Commission`s Office for Analysis and Evaluation of Operational Data (AEOD) review of operating experience of main turbine-generator overspeed and overspeed protection systems. It includes an indepth examination of the turbine overspeed event which occurred on November 9, 1991, at the Salem Unit 2 Nuclear Power Plant. It also provides information concerning actions taken by other utilities and the turbine manufacturers as a result of the Salem overspeed event. AEOD`s study reviewed operating procedures and plant practices. It noted differences between turbine manufacturer designs and recommendations for operations, maintenance, and testing, and also identified significant variations in the manner that individual plants maintain and test their turbine overspeed protection systems. AEOD`s study provides insight into the shortcomings in the design, operation, maintenance, testing, and human factors associated with turbine overspeed protection systems. Operating experience indicates that the frequency of turbine overspeed events is higher than previously thought and that the bases for demonstrating compliance with NRC`s General Design Criterion (GDC) 4, Environmental and dynamic effects design bases, may be nonconservative with respect to the assumed frequency.

Ornstein, H.L.

1995-04-01

153

3D computations of flow field in a guide vane blading designed by means of 2D model for a low head hydraulic turbine  

NASA Astrophysics Data System (ADS)

The paper presents the main parameters of the flow field behind the guide vane cascade designed by means of 2D inverse problem and following check by means of 3D commercial program ANSYS/Fluent applied for a direct problem. This approach of using different models reflects the contemporary design procedure for non-standardized turbomachinery stage. Depending on the model, the set of conservation equation to be solved differs, although the physical background remains the same. The example of computations for guide vane cascade for a low head hydraulic turbine is presented.

Krzemianowski, Z.; Puzyrewski, R.

2014-08-01

154

Wind Turbine Generator Physics: Gear Boxes and Blades  

NSDL National Science Digital Library

This module, produced by the Wind Technician TV project from Highland Community College, introduces students to the gear boxes and blades of wind turbines. The module consists of four lessons: gear box solids and liquids, blades- force analysis, gear box heat transfer and gearbox force and stress analysis. The lessons include audio and animated visuals as well as interactive simulations. Each lesson includes a PDF document with the lesson's text and images. Skill check activities are also included.

2012-10-24

155

EFFECT OF PITCH CONTROL AND POWER CONDITIONING ON POWER QUALITY OF VARIABLE SPEED WIND TURBINE GENERATORS  

E-print Network

of these systems is that the induction generators require reactive power from the grid or capacitor banks to meetEFFECT OF PITCH CONTROL AND POWER CONDITIONING ON POWER QUALITY OF VARIABLE SPEED WIND TURBINE GENERATORS Hari Sharma* Trevor Pryor* Syed Islam** *Murdoch University Energy Research Institute (MUERI

156

Torque and power limitations of variable speed wind turbines using pitch control and generator power control  

Microsoft Academic Search

Variable speed operation of wind turbines has the potential to in crease energy capture and reduce fatigue damage, compared with fixed speed operation. Cage induction generators with their brush-less and rigid structure are at present widely used for fixed speed wind systems. To make the cage induction generators widely used also at variable speed systems, proper control strategies should be

N. Horiuchi; T. Kawahito

2001-01-01

157

Using gas-turbine power stations with aircraft engines for power-and-heat generation  

Microsoft Academic Search

The purpose is to determine certain power engineering indices of gas turbine engines used to generate electricity and heat. The RD-3M-500 engine is discussed. It is concluded that the engine would be useful for the generation of heat and electricity in regions located far from large power sources when these regions had limited water and fuel supplies.

A. A. Margaryan

1984-01-01

158

AN INTEGRATED DESIGN OF REACTOR AND TURBINE GENERATOR SECTIONS OF THE ENRICO FERMI ATOMIC POWER PLANT  

Microsoft Academic Search

The design of the steam-generating system and the turbine generator ; system of the Enrico Fermi power plant is given. The terms of the agreement ; between The Power Reactor Development Company and The Detroit Edison Company are ; discussed. (W.D.M.);

R. C. Kirkby; C. M. Heidel

1958-01-01

159

Executive summary: Mod-1 wind turbine generator analysis and design report  

NASA Technical Reports Server (NTRS)

Activities leading to the detail design of a wind turbine generator having a nominal rating of 1.8 megawatts are reported. Topics covered include (1) system description; (2) structural dynamics; (3) stability analysis; (4) mechanical subassemblies design; (5) power generation subsystem; and (6) control and instrumentation subsystem.

1979-01-01

160

Parallel Operation of Wind Turbine, Fuel Cell, and Diesel Generation Sources: Preprint  

Microsoft Academic Search

We investigated a small isolated hybrid power system that used a parallel combination of dispatchable and non-dispatchable power generation sources. The non-dispatchable generation came from a nature-dependent wind turbine, and the dispatchable generations were a fuel cell and a diesel generator. On the load side, the non-dispatchable portion was the village load, and the dispatchable portion was the energy storage,

E. Muljadi; C. Wang; M. H. Nehrir

2004-01-01

161

Biphase turbine for reverse osmosis desalination. Final report  

SciTech Connect

A new hydraulic reaction turbine was designed to recover the power available in the high-pressure waste-brine stream of reverse osmosis desalination systems. A reaction turbine sized for reverse-osmosis systems producing 600 gph was built and tested. The turbine performed well driving either a variable-speed pump or an electrical generator. Measured turbine efficiency (shaft power divided by available power) was 63%, compared with a prediction of 67%. The turbine can be built with larger capacity to reduce the size, weight and power consumption of reverse osmosis desalination systems. Efficiency of larger units is predicted to lie in the range of 65 to 70%.

Limburg, P.L.

1982-12-01

162

Mod-5A wind turbine generator program design report. Volume 4: Drawings and specifications, book 4  

NASA Technical Reports Server (NTRS)

The design, development and analysis of the 7.3 MW MOD-5A wind turbine generator are documented. There are four volumes. This volume contains the drawings and specifications that were developed in preparation for building the MOD-5A wind turbine generator. This volume contains 5 books of which this is the fourth, providing drawings 47A380128 through 47A387125. In addition to the parts listing and where-used list, the logic design of the controller software and the code listing of the controller software are provided. Also given are the aerodynamic profile coordinates.

1984-01-01

163

Case History of Reapplication of a 2500 KW Steam Turbine/Gear Drive Generator  

E-print Network

with the highlights of the engineering work required to insure the mechanical operation of the string of equipment. specification of Equipment The customer was in need of a base load turbine/generator set to supply the electrical power to operate the plant... of the engineering work required to insure the mechanical operation of the string of equipment. specification of Equipment The customer was in need of a base load turbine/generator set to supply the electrical power to operate the plant. The power requirements called...

Smith, S.

164

Measurements and observations of noise from a 4.2 megawatt (WTS-4) wind turbine generator  

NASA Technical Reports Server (NTRS)

Noise measurements and calculations are being made for large wind turbine generators to develop a data base for use in designing and siting such systems for community acceptance. As part of this program, measurements were made on the WTS-4 wind turbine generator during its acceptance runs. This paper presents the results of these exploratory measurements for power output conditions in the range 1.0 to 4.2 MW. Data include noise levels, spectra, radiation patterns, effects of distance, and the associated perception thresholds for use in the further development of acceptance criteria for this type of machine.

Shepherd, K. P.; Hubbard, H. H.

1983-01-01

165

Representation of Type 4 wind turbine generator for steady state short-circuit calculations  

NASA Astrophysics Data System (ADS)

Various technical impacts are associated to the interconnection of wind turbine generators to the grid. Among them, the increase of short-circuit levels along with its effect on the settings of protecting relays has long acted as an important inhibiting factor for the interconnection of new wind power plants to the grid. This is especially true at the medium voltage level where networks operate close to their short-circuit design value [1]. As renewable energies are progressively replacing traditional power generation sources, short-circuit studies need to adequately assess the impact of newly interconnected wind power plants on the fault level of the network. For planning and design purposes, short-circuit studies are usually performed using steady-state short-circuit programs. Unfortunately, very few have developed models of wind turbine generators that accurately estimate their fault contribution in the phase domain. In particular, no commercial fault-flow analysis program specifically addresses the modeling of inverter-based wind turbine generators which behavior is based on the inverter's characteristics rather than the generator's. The main contribution of this research work is the development of a simplified and yet accurate model of full-scale converter based wind turbine generator, also called Type 4 wind turbine generator, for steady-state short-circuit calculations. The model reproduces the real behavior of the Type 4 wind turbine generator under fault conditions by correctly accounting for the effect of the full-scale converter. The data used for the model is easily accessible to planning engineers. An additional contribution of this research work is the development of a short-circuit algorithm adapted to support the proposed model of Type 4 wind-turbine generator. Short-circuit algorithm based on modified-augmented-nodal analysis (MANA) is solved iteratively to accommodate the proposed model. The algorithm is successfully implemented in CYME 7.0, a commercial distribution system analysis program, to perform short-circuit calculations in multiphase complex unbalanced systems. Detailed study of the behavior of Type 4 wind turbine generator using electromagnetic type programs like EMTP-RV has assessed that the proposed model closely reproduces the real behavior of the wind turbine generator under steady-state fault conditions. The proposed model is then implemented in CYME 7.0 and validated for different fault scenarios using the Fortis Alberta 25 kV distribution system as benchmark. The fault contribution obtained from the proposed model is compared against the one obtained from the previous model implemented in CYME 7.0. The validation test cases show that the proposed model estimates the fault contribution of the wind turbine generator with better precision than the former models. Besides, the performance and robustness of the short-circuit algorithm developed allow handling unbalanced networks with inverter interfaced wind turbine generators as it is based on the MANA formulation.

Kamara, Wouleye

166

National Renewable Energy Laboratory program on lightning risk and wind turbine generator protection  

SciTech Connect

In the early development of wind turbine generators (WTG) in the United States, wind farms were primarily located in California where lightning activity is the lowest in the United States. As such, lightning protection for wind turbines was not considered to be a major issue for designers or wind farm operators. However, wind turbine installations are expanding into the Midwest, Southwest and other regions of the United States where lightning activity is significantly more intense and lightning damage to wind turbines is more common. There is a growing need, therefore, to better understand lightning activity on wind farms and to improve wind turbine lightning protection systems. In support of the U.S. Department of Energy/Electric Power Research Institute (DOE/EPRI) Utility Wind Turbine Verification Program (TVP), the National Renewable Energy Laboratory (NREL) has recently begun to take steps to determine the extent of damage due to lightning and the effectiveness of various lightning protection techniques for wind power plants. Working through the TVP program, NREL will also perform outreach and education to (1) help manufacturers to provide equipment that is adequately designed to survive lightning, (2) make sure that operators are aware of effective safety procedures, and (3) help site designers and wind farm developers take the risk of lightning into account as effectively as possible.

Muljadi, E. [National Renewable Energy Lab., Golden, CO (United States); McNiff, B. [McNiff Light Industry, Blue Hill, ME (United States)

1997-12-31

167

Development tests for the 2.5 megawatt Mod-2 wind turbine generator  

NASA Technical Reports Server (NTRS)

The 2.5 megawatt MOD-2 wind turbine generator test program is discussed. The development of the 2.5 megawatt MOD-2 wind turbine generator included an extensive program of testing which encompassed verification of analytical procedures, component development, and integrated system verification. The test program was to assure achievement of the thirty year design operational life of the wind turbine system as well as to minimize costly design modifications which would otherwise have been required during on site system testing. Computer codes were modified, fatigue life of structure and dynamic components were verified, mechanical and electrical component and subsystems were functionally checked and modified where necessary to meet system specifications, and measured dynamic responses of coupled systems confirmed analytical predictions.

Andrews, J. S.; Baskin, J. M.

1982-01-01

168

554 IEEE JOURNAL OF OCEANIC ENGINEERING, VOL. 37, NO. 3, JULY 2012 Generator Systems for Marine Current Turbine  

E-print Network

554 IEEE JOURNAL OF OCEANIC ENGINEERING, VOL. 37, NO. 3, JULY 2012 Generator Systems for Marine for marine current turbines are mainly related to works that have been carried out on wind turbines and ship propellers. It is then obvious that many electric generator topologies could be used for marine current

Paris-Sud XI, Université de

169

Mod-5A wind turbine generator program design report. Volume 3: Final design and system description, book 1  

NASA Technical Reports Server (NTRS)

The design, development and analysis of the 7.3 MW MOD-5A wind turbine generator is documented. Volume 3, book 1 describes the performance and characteristics of the MOD-5A wind turbine generator in its final configuration. Each subsystem - the rotor, drivetrain, nacelle, tower and foundation is described in detail.

1984-01-01

170

Mod-5A wind turbine generator program design report. Volume 3: Final design and system description, book 1  

NASA Astrophysics Data System (ADS)

The design, development and analysis of the 7.3 MW MOD-5A wind turbine generator is documented. Volume 3, book 1 describes the performance and characteristics of the MOD-5A wind turbine generator in its final configuration. Each subsystem - the rotor, drivetrain, nacelle, tower and foundation is described in detail.

1984-08-01

171

Wind turbine generator interaction with conventional diesel generators on Block Island, Rhode Island. Volume 1: Executive summary  

NASA Technical Reports Server (NTRS)

Primary results are summarized for a three-part study involving the effects of connecting a MOD-OA wind turbine generator to an isolated diesel power system. The MOD-OA installation considered was the third of four experimental nominal 200 kW wind turbines connected to various utilities under the Federal Wind Energy Program and was characterized by the highest wind energy penetration levels of four sites. The study analyses address: fuel displacement, dynamic interaction, and three modes of reactive power control. These analyses all have as their basis the results of the data acquisition program conducted on Block Island, Rhode Island.

Wilreker, V. F.; Stiller, P. H.; Scott, G. W.; Kruse, V. J.; Smith, R. F.

1984-01-01

172

MOD-1 Wind Turbine Generator Analysis and Design Report, Volume 2  

NASA Technical Reports Server (NTRS)

The MOD-1 detail design is appended. The supporting analyses presented include a parametric system trade study, a verification of the computer codes used for rotor loads analysis, a metal blade study, and a definition of the design loads at each principal wind turbine generator interface for critical loading conditions. Shipping and assembly requirements, composite blade development, and electrical stability are also discussed.

1979-01-01

173

Mod-1 wind turbine generator analysis and design report, volume 1  

NASA Technical Reports Server (NTRS)

The activities leading to the completion of detail design of the MOD-1 wind turbine generator are described. Emphasis is placed on the description of the design as it finally evolved. However, the steps through which the design progressed are also traced in order to understand the major design decisions.

1979-01-01

174

Model OA Wind Turbine Generator FEMA (Failure Modes and Effects Analysis)  

Microsoft Academic Search

This report presents the results of Failure Modes and Effects Analysis (FMEA) conducted for the Wind Turbine Generators. The FMEA was performed for the functional modes of each system, subsystem, or component. The single-point failures were eliminated for most of the systems. The blade system was the only exception. The qualitative probability of a blade separating was estimated at Level

W. E. Klein; V. R. Lalli

1989-01-01

175

Turbine-Generator Shaft Torques and Fatigue: Part I - Simulation Methods and Fatigue Analysis  

Microsoft Academic Search

This paper is the first of two papers concerned with the effects of power system disturbances and operating practices upon turbine-generator shafts. The paper presents techniques for the analysis of shaft fatigue damage due to torsional oscillations. The detailed development of a fatigue model is presented. An example illustrates the use of the techniques for calculation of the loss of

M. C. Jackson; S. D. Umans; R. D. Dunlop; S. H. Horowitz; A. C. Parikh

1979-01-01

176

Fault Diagnosis of Steam Turbine-Generator Sets Using Evolutionary Based Support Vector Machine  

Microsoft Academic Search

This paper presents particle swarm optimization (PSO)-based support vector machine (SVM) to extract the optimal support vector from database for vibration fault diagnosis of steam turbine-generator sets (STGS). In this paper, the SVM is used to construct the vibration fault diagnosis model and the proposed PSO is then adopted to determine automatically the optimal parameters in the SVM. Test results

Huo-Ching Sun; Yann-Chang Huang

2012-01-01

177

Cycle Analysis on Ocean Geothermal Power Generation using Multi-staged Turbine  

E-print Network

Renewable energy.. Geothermal heat, Ocean energy, etc.. Geothermal heat.. one of the humankind's oldestCycle Analysis on Ocean Geothermal Power Generation using Multi-staged Turbine 2013. 09. 11 Korea.. depletion of usable fossil fuels and problems on the global environment Interest for alternative energy

178

Development of a 40-kilowatt wind turbine generator. Phase 1: Design and analysis  

Microsoft Academic Search

Kaman Aerospace Corporation is currently engaged in a program to design, fabricate and test a horizontal axis wind turbine generator capable of producing 40 kW electrical output power in a 20 mph wind. The results covering design tradeoff studies, preliminary design and analysis and the final design effort are presented. Additional work included cost studies and test planning activities.

H. E. Howes; M. A. Bowes; R. Perley

1981-01-01

179

Development of a 40-kilowatt wind turbine generator. Phase 1: Design and analysis  

NASA Astrophysics Data System (ADS)

Kaman Aerospace Corporation is currently engaged in a program to design, fabricate and test a horizontal axis wind turbine generator capable of producing 40 kW electrical output power in a 20 mph wind. The results covering design tradeoff studies, preliminary design and analysis and the final design effort are presented. Additional work included cost studies and test planning activities.

Howes, H. E.; Bowes, M. A.; Perley, R.

1981-02-01

180

Control design for a wind turbine-generator using output feedback  

NASA Technical Reports Server (NTRS)

The modeling and approach to control design for a large horizontal axis wind turbine (WT) generator are presented. The control design is based on a suboptimal output regulator which allows coordinated control of WT blade pitch angle and field voltage for the purposes of regulating electrical power and terminal voltage. Results of detailed non-linear simulation tests of this controller are shown.

Javid, S. H.; Murdoch, A.; Winkelman, J. R.

1981-01-01

181

Wind turbine generator interaction with conventional diesel generators on Block Island, Rhode Island. Volume 2: Data analysis  

NASA Technical Reports Server (NTRS)

Assessing the performance of a MOD-OA horizontal axis wind turbine connected to an isolated diesel utility, a comprehensive data measurement program was conducted on the Block Island Power Company installation on Block Island, Rhode Island. The detailed results of that program focusing on three principal areas of (1) fuel displacement (savings), (2) dynamic interaction between the diesel utility and the wind turbine, (3) effects of three models of wind turbine reactive power control are presented. The approximate two month duration of the data acquisition program conducted in the winter months (February into April 1982) revealed performance during periods of highest wind energy penetration and hence severity of operation. Even under such conditions fuel savings were significant resulting in a fuel reduction of 6.7% while the MOD-OA was generating 10.7% of the total electrical energy. Also, electrical disturbance and interactive effects were of an acceptable level.

Wilreker, V. F.; Stiller, P. H.; Scott, G. W.; Kruse, V. J.; Smith, R. F.

1984-01-01

182

Parallel Operation of Wind Turbine, Fuel Cell, and Diesel Generation Sources: Preprint  

SciTech Connect

We investigated a small isolated hybrid power system that used a parallel combination of dispatchable and non-dispatchable power generation sources. The non-dispatchable generation came from a nature-dependent wind turbine, and the dispatchable generations were a fuel cell and a diesel generator. On the load side, the non-dispatchable portion was the village load, and the dispatchable portion was the energy storage, which could be in many different forms (e.g., space/water heater, electrolysis, battery charger, etc.) The interaction among different generation sources and the loads was investigated. Simulation results showed the effect of the proposed system on voltage and frequency fluctuations.

Muljadi, E.; Wang, C.; Nehrir, M. H.

2004-06-01

183

Advances in Thermal Spray Coatings for Gas Turbines and Energy Generation: A Review  

NASA Astrophysics Data System (ADS)

Functional coatings are widely used in energy generation equipment in industries such as renewables, oil and gas, propulsion engines, and gas turbines. Intelligent thermal spray processing is vital in many of these areas for efficient manufacturing. Advanced thermal spray coating applications include thermal management, wear, oxidation, corrosion resistance, sealing systems, vibration and sound absorbance, and component repair. This paper reviews the current status of materials, equipment, processing, and properties' aspects for key coatings in the energy industry, especially the developments in large-scale gas turbines. In addition to the most recent industrial advances in thermal spray technologies, future technical needs are also highlighted.

Hardwicke, Canan U.; Lau, Yuk-Chiu

2013-06-01

184

A Novel 500kW High-Speed Turbine PM Synchronous Generator Set for Distributed Power Generation  

NASA Astrophysics Data System (ADS)

The paper presents a power generation system based on the cogeneration of heat and electricity with a novel high speed turbogenerator. The machine consists of a single stage steam turbine and a directly coupled permanent magnet synchronous generator in one constructional unit. A PWM IGBT rectifier is the load to the generator and a PWM IGBT three-phase four-wire inverter feeds the power into the low voltage mains. In order to increase the turbine efficiency at light load, variable speed operation of the turbogenerator is realized. Different control schemes for mains parallel operation and stand alone operation are presented. The control schemes allow for the use of a lookup table based control with a speed-power-characteristic or for the use of a maximum power point tracker. Measurement results from the successfully tested turbogenerator set are presented.

Wendt, Sven; Benecke, Frank; Güldner, Henry

185

A three-dimensional algebraic grid generation scheme for gas turbine combustors with inclined slots  

NASA Technical Reports Server (NTRS)

A 3D algebraic grid generation scheme is presented for generating the grid points inside gas turbine combustors with inclined slots. The scheme is based on the 2D transfinite interpolation method. Since the scheme is a 2D approach, it is very efficient and can easily be extended to gas turbine combustors with either dilution hole or slot configurations. To demonstrate the feasibility and the usefulness of the technique, a numerical study of the quick-quench/lean-combustion (QQ/LC) zones of a staged turbine combustor is given. Preliminary results illustrate some of the major features of the flow and temperature fields in the QQ/LC zones. Formation of co- and counter-rotating bulk flow and shape temperature fields can be observed clearly, and the resulting patterns are consistent with experimental observations typical of the confined slanted jet-in-cross flow. Numerical solutions show the method to be an efficient and reliable tool for generating computational grids for analyzing gas turbine combustors with slanted slots.

Yang, S. L.; Cline, M. C.; Chen, R.; Chang, Y. L.

1993-01-01

186

Tungsten fiber reinforced FeCralY: A first generation composite turbine blade material  

NASA Technical Reports Server (NTRS)

Tungsten-fiber/FeCrAlY (W/FeCrAlY) was identified as a promising aircraft engine, first generation, turbine blade composite material. Based on available data, W/FeCrAlY should have the stress-rupture, creep, tensile, fatigue, and impact strengths required for turbine blades operating from 1250 to 1370 K. It should also have adequate oxidation, hot corrosion, and thermal cycling damage resistance as well as high thermal conductivity. Concepts for potentially low cost blade fabrication were developed. These concepts were used to design a first stage JT9D convection cooled turbine blade having a calculated 50 K use-temperature advantage over the directionally solidified superalloy blade.

Petrasek, D. W.; Winsa, E. A.; Westfall, L. J.; Signorelli, R. A.

1979-01-01

187

Advanced Seal Technology Role in Meeting Next Generation Turbine Engine Goals  

NASA Technical Reports Server (NTRS)

Cycle studies have shown the benefits of increasing engine pressure ratios and cycle temperatures to decrease engine weight and improve performance in next generation turbine engines. Advanced seals have been identified as critical in meeting engine goals for specific fuel consumption, thrust-to-weight, emissions, durability and operating costs. NASA and the industry are identifying and developing engine and sealing technologies that will result in dramatic improvements and address the goals for engines entering service in the 2005-2007 time frame. This paper provides an overview of advanced seal technology requirements and highlights the results of a preliminary design effort to implement advanced seals into a regional aircraft turbine engine. This study examines in great detail the benefits of applying advanced seals in the high pressure turbine region of the engine. Low leakage film-riding seals can cut in half the estimated 4% cycle air currently used to purge the high pressure turbine cavities. These savings can be applied in one of several ways. Holding rotor inlet temperature (RIT) constant the engine specific fuel consumption can be reduced 0.9%, or thrust could be increased 2.5%, or mission fuel burn could be reduced 1.3%. Alternatively, RIT could be lowered 20 'F resulting in a 50% increase in turbine blade life reducing overall regional aircraft maintenance and fuel bum direct operating costs by nearly 1%. Thermal, structural, secondary-air systems, safety (seal failure and effect), and emissions analyses have shown the proposed design is feasible.

Steinetz, Bruce M.; Hendricks, Robert C.; Munson, John

1999-01-01

188

Typical steam generator tube rupture (SGTR) effect on thermo-hydraulic parameters of VVER-1000 primary loop  

Microsoft Academic Search

In operation of nuclear power plant, it is very important to evaluate different accident scenarios in actual plant conditions. One of the main accidents is (SGTR) steam generator tube rupture in the field of nuclear safety. In this research variation of thermo-hydraulics parameters in primary loop under SGTR accident in VVER-1000 nuclear power plant is analyzed by Relap5\\/Mod 3.2 thermo-hydraulics

A. Zare; M. R. Nematollahi; K. Hadad; M. A. Mozaffari

189

Design and construction of a thermophotovoltaic generator using turbine combustion gas  

SciTech Connect

This US Naval Academy project involves the development of a prototype thermophotovoltaic (TPV) generator that uses a General Electric T-58 helicopter gas turbine as the heat source. The goals of this project were to demonstrate the viability of using TPV and external combustion gases to generate electricity, and develop a system which could also be used for materials testing. The generator was modularly designed so that different materials could be tested at a later date. The combustion gas was tapped from the T-58`s combustor through one of the two igniter ports and extracted through a silicon carbide matrix ceramic composite tube into a similarly constructed ceramic composite radiant emitter. The ceramic radiant emitters is heated by the combustion gas via convection, and then serves the TPV generator by radiating the heat outwards where it can be absorbed by thermophotovoltaic cells and converted directly into electricity. The gas turbine and generator module are monitored by a data acquisition system that performs both data collection and control functions. This paper details the design of the TPV generator. It also gives results of initial tests with the gas turbine.

Erickson, T.A.; Lindler, K.W.; Harper, M.J. [Naval Academy, Annapolis, MD (United States). Dept. of Naval Architecture, Ocean, and Marine Engineering

1997-07-01

190

Hydraulic waste energy recovery, Phase 2  

SciTech Connect

The energy required for booster station operation is supplied by the electrical utility company and has an associated cost. Energy removed by pressure reducing valves in the system is lost or wasted. The objective of this project is to capture the wasted hydraulic energy with in-line turbines. In this application, the in-line turbines act as pressure reducing valves while removing energy from the water distribution system and converting it to electrical energy. The North Service Center pumping station was selected for the pilot program due to the availability of a wide range in pressure drop and flow, which are necessary for hydraulic energy recovery. The research performed during this project resulted in documentation of technical, economic, installation, and operational information necessary for local government officials to make an informed judgement as it relates to in-line turbine generation.

Not Available

1992-02-01

191

An optimal design of coreless direct-drive axial flux permanent magnet generator for wind turbine  

NASA Astrophysics Data System (ADS)

Different types of generators are currently being used in wind power technology. The commonly used are induction generator (IG), doubly-fed induction generator (DFIG), electrically excited synchronous generator (EESG) and permanent magnet synchronous generator (PMSG). However, the use of PMSG is rapidly increasing because of advantages such as higher power density, better controllability and higher reliability. This paper presents an innovative design of a low-speed modular, direct-drive axial flux permanent magnet (AFPM) generator with coreless stator and rotor for a wind turbine power generation system that is developed using mathematical and analytical methods. This innovative design is implemented in MATLAB / Simulink environment using dynamic modelling techniques. The main focus of this research is to improve efficiency of the wind power generation system by investigating electromagnetic and structural features of AFPM generator during its operation in wind turbine. The design is validated by comparing its performance with standard models of existing wind power generators. The comparison results demonstrate that the proposed model for the wind power generator exhibits number of advantages such as improved efficiency with variable speed operation, higher energy yield, lighter weight and better wind power utilization.

Ahmed, D.; Ahmad, A.

2013-06-01

192

Power train analysis for the DOE/NASA 100-kW wind turbine generator  

NASA Technical Reports Server (NTRS)

Progress in explaining variations of power experienced in the on-line operation of a 100 kW experimental wind turbine-generator is reported. Data are presented that show the oscillations tend to be characteristic of a wind-driven synchronous generator because of low torsional damping in the power train, resonances of its large structure, and excitation by unsteady and nonuniform wind flow. The report includes dynamic analysis of the drive-train torsion, the generator, passive driveline damping, and active pitch control as well as correlation with experimental recordings. The analysis assumes one machine on an infinite bus with constant generator-field excitation.

Seidel, R. C.; Gold, H.; Wenzel, L. M.

1978-01-01

193

A microfabricated ElectroQuasiStatic induction turbine-generator  

E-print Network

An ElectroQuasiStatic (EQS) induction machine has been fabricated and has generated net electric power. A maximum power output of 192 [mu]W at 235 krpm has been measured under driven excitation of the six phases. Self ...

Steyn, J. Lodewyk (Jasper Lodewyk), 1976-

2005-01-01

194

Development of a Direct Drive Permanent Magnet Generator for Small Wind Turbines  

SciTech Connect

In this program, TIAX performed the conceptual design and analysis of an innovative, modular, direct-drive permanent magnet generator (PMG) for use in small wind turbines that range in power rating from 25 kW to 100 kW. TIAX adapted an approach that has been successfully demonstrated in high volume consumer products such as direct-drive washing machines and portable generators. An electromagnetic model was created and the modular PMG design was compared to an illustrative non-modular design. The resulting projections show that the modular design can achieve significant reductions in size, weight, and manufacturing cost without compromising efficiency. Reducing generator size and weight can also lower the size and weight of other wind turbine components and hence their manufacturing cost.

Chertok, Allan; Hablanian, David; McTaggart, Paul; DOE Project Officer - Keith Bennett

2004-11-16

195

Optimized working conditions for a thermoelectric generator as a topping cycle for gas turbines  

NASA Astrophysics Data System (ADS)

This paper presents a model for a theoretical maximum efficiency of a thermoelectric generator integrated with a Brayton-cycle engine. The thermoelectric cycle is presented in two configurations as a topping cycle and a preheating topping cycle. For the topping cycle configuration, the thermoelectric generator receives heat from a high-temperature heat source and produces electrical work before rejecting heat to a Brayton cycle. For the preheating topping cycle, the rejected heat from the thermoelectric generator partially heats the compressed working fluid of the Brayton cycle before a secondary heater delivers heat to the working fluid directly from the heat source. The thermoelectric topping cycle efficiency increases as the temperature difference between the hot- and cold-side increases; however, this limits the heat transfer possible to the Brayton cycle, which in turn reduces power generation from the Brayton cycle. This model identifies the optimum operating parameters of the thermoelectric and Brayton cycles to obtain the maximum thermal efficiency of the combined cycle. In both configurations, efficiency gains are larger at low-temperature Brayton cycles. Although a thermoelectric generator (TEG) topping cycle enhances efficiency for a low temperature turbine, efficiency cannot exceed a high temperature gas turbine. Using a TEG topping cycle is limited to cases when space or price for a high temperature turbine cannot be justified. A design to achieve the preheating thermoelectric topping cycle is also presented.

Brady Knowles, C.; Lee, Hohyun

2012-10-01

196

A Parametric Study of the Thermal-Hydraulic Response of Supercritical Light Water Reactors During Loss-of-Feedwater and Turbine-Trip Events  

SciTech Connect

The Idaho National Engineering and Environmental Laboratory in investigating the feasibility of supercritical light water reactors for low-cost electric power production through a Nuclear Energy Research Initiative Project sponsored by the United State Department of Energy. The project is evaluating a variety of technical issues related to the fuel and reactor design, material corrosion, and safety characteristics. This paper presents the results of parametric calculations using the RELAP5 computer code to characterize the thermal-hydraulic response of supercritical reactors to transients initiated by loss-of-feedwater and turbine-trip events. The purpose of the calculations was to aid in the design of the safety systems by determining the time available for the safety systems to respond and their required capacities.

Cliff B. Davis; Jacopo Buongiorno; Philip E. MacDonald

2003-09-01

197

Fuzzy-logic-based maximum power point tracking strategy for Pmsg variable-speed wind turbine generation systems  

Microsoft Academic Search

In order to achieve maximum power point tracking (MPPT) for wind power generation systems, the rotating speed of wind turbines should be adjusted in the real time according to wind speeds. However, fast wind speed variations and heavy inertia compromise the MPPT control of a wind turbine. In this paper, a fuzzy-logic based MPPT strategy is proposed for PMSG variable

Qingrong Zeng; Liuchen Chang; Riming Shao

2008-01-01

198

Investigation of vortex generators for augmentation of wind turbine power performance  

SciTech Connect

This study focuses on the use of vortex generators (VGs) for performance augmentation of the stall-regulated AWT-26 wind turbine. The goal was to design a VG array which would increase annual energy production (AEP) by increasing power output at moderate wind speeds, without adversely affecting the loads or stall-regulation performance of the turbine. Wind tunnel experiments were conducted at the University of Washington to evaluate the effect of VGs on the AWT-26 blade, which is lofted from National Renewable Energy Laboratory (NREL) S-series airfoils. Based on wind-tunnel results and analysis, a VG array was designed and then tested on the AWT-26 prototype, designated P1. Performance and loads data were measured for P1, both with and without VGs installed. the turbine performance with VGs met most of the design requirements; power output was increased at moderate wind speeds with a negligible effect on peak power. However, VG drag penalties caused a loss in power output for low wind speeds, such that performance with VGs resulted in a net decrease in AEP for sites having annual average wind speeds up to 8.5 m/s. While the present work did not lead to improved AEP for the AWT-2 turbine, it does provide insight into performance augmentation of wind turbines with VGs. The safe design of a VG array for a stall-regulated turbine has been demonstrated, and several issues involving optimal performance with VGs have been identified and addressed. 15 refs., 34 figs., 10 tabs.

Griffin, D.A. [Lynette (R.) and Associates, Seattle, WA (United States)

1996-12-01

199

Design of a 3 kW wind turbine generator with thin airfoil blades  

SciTech Connect

Three blades of a 3 kW prototype wind turbine generator were designed with thin airfoil and a tip speed ratio of 3. The wind turbine has been controlled via two control methods: the variable pitch angle and by regulation of the field current of the generator and examined under real wind conditions. The characteristics of the thin airfoil, called ''Seven arcs thin airfoil'' named so because the airfoil is composed of seven circular arcs, are analyzed with the airfoil design and analysis program XFOIL. The thin airfoil blade is designed and calculated by blade element and momentum theory. The performance characteristics of the machine such as rotational speed, generator output as well as stability for wind speed changes are described. In the case of average wind speeds of 10 m/s and a maximum of 19 m/s, the automatically controlled wind turbine ran safely through rough wind conditions and showed an average generator output of 1105 W and a power coefficient 0.14. (author)

Ameku, Kazumasa; Nagai, Baku M.; Roy, Jitendro Nath [Faculty of Mechanical Engineering, University of the Ryukyus, 1 Senbaru, Nishihara-cho, Okinawa 903-0213 (Japan)

2008-09-15

200

Method for changing removable bearing for a wind turbine generator  

DOEpatents

A wind generator having removable change-out bearings includes a rotor and a stator, locking bolts configured to lock the rotor and stator, a removable bearing sub-assembly having at least one shrunk-on bearing installed, and removable mounting bolts configured to engage the bearing sub-assembly and to allow the removable bearing sub-assembly to be removed when the removable mounting bolts are removed.

Bagepalli, Bharat Sampathkumaran (Niskayuna, NY); Jansen, Patrick Lee (Scotia, NY); Gadre, Aniruddha Dattatraya (Rexford, NY)

2008-04-22

201

RELAP5/MOD3 Analysis of Transient Steam-Generator Behavior During Turbine Trip Test of a Prototype Fast Breeder Reactor MONJU  

SciTech Connect

In order to develop a thermal-hydraulic model of the steam-generator (SG) to simulate transient phenomena in the sodium cooled fast breeder reactor (FBR) MONJU, Japan Nuclear Energy Safety Organization (JNES) verified the SG model using the RELAP5/MOD3 code against the results of the turbine trip test at a 40% power load of MONJU. The modeling by using RELAP5 was considered to explain the significant observed behaviors of the pressure and the temperature of the EV steam outlet, and the temperature of water supply distributing piping till 600 seconds after the turbine trip. The analysis results of these behaviors showed good agreement with the test results based on results of parameter study as the blow efficiency (release coef.) and heat transferred from the helical coil region to the down-comer (temperature heating down-comer tubes). It was found that the RELAP5/MOD3 code with a two-fluids model can predict well the physical situation: the gas-phase of steam generated by the decompression boiling moves upward in the down-comer tubes accompanied by the enthalpy increase of the water supply chambers; and that the pressure change of a 'shoulder' like shape is induced by the mass balance between the steam mass generated in the down-comer tubes and the steam mass blown from the SG. The applicability of RELAP5/MOD3 to SG modeling was confirmed by simulating the actual FBR system. (authors)

Yoshihisa Shindo; Hiroshi Endo; Tomoko Ishizu; Kazuo Haga [Japan Nuclear Energy Safety Organization (Japan)

2006-07-01

202

Preliminary analysis of performance and loads data from the 2-megawatt mod-1 wind turbine generator  

NASA Technical Reports Server (NTRS)

Preliminary test data on output power versus wind speed, rotor blade loads, system dynamic behavior, and start-stop characteristics on the Mod-1 wind turbine generator are presented. These data were analyzed statistically and are compared with design predictions of system performance and loads. To date, the Mod-1 wind turbine generator has produced up to 1.5 MW of power, with a measured power versus wind speed curve which agrees closely with design. Blade loads were measured at wind speeds up to 14 m/s and also during rapid shutdowns. Peak transient loads during the most severe shutdowns are less than the design limit loads. On the inboard blade sections, fatigue loads are approximately equal to the design cyclic loads. On the outboard blade sections, however, measured cyclic loads are significantly larger than design values, but they do not appear to exceed fatigue allowable loads as yet.

Spera, D. A.; Viterna, L. A.; Richards, T. R.; Neustadter, H. E.

1979-01-01

203

Conceptual design of the 7 megawatt Mod-5B wind turbine generator  

NASA Technical Reports Server (NTRS)

Similar to MOD-2, the MOD-5B wind turbine generator system is designed for the sole purpose of providing electrical power for distribution by a major utility network. The objectives of the MOD-2 and MOD-5B programs are essentially identical with one important exception; the cost-of-electricity (COE) target is reduced from 4 cent/Kwhr on MOD-2 to 3 cent/Kwhr on MOD-5B, based on mid 1977 dollars and large quantity production. The MOD-5B concept studies and eventual concept selection confirmed that the program COE targets could not only be achieved but substantially bettered. Starting from the established MOD-2 technology as a base, this achievement resulted from a combination of concept changes, size changes, and design refinements. The result of this effort is a wind turbine system that can compete with conventional power generation over significant geographical areas, increasing commercial market potential by an order of magnitude.

Douglas, R. R.

1982-01-01

204

Probability assessment of turbine-generator shaft torque following severe disturbances on the system supply  

Microsoft Academic Search

This paper presents a probabilistic approach to the evaluation of the maximum torsional torques induced in turbine generator shafts following severe supply network disturbances with clearance, during high-speed auto-reclosure, and resulting from mal-synchronisation. In this context the investigations have been conducted on a range of machines taking into consideration the uncertainty of several factors associated with the practical operation of

T. J. Hammons; C. K. Lim

1999-01-01

205

A 1?1 prototype of power generation system based upon cross-flow water turbines  

Microsoft Academic Search

This paper deals with the conception and building of an electrical power generation prototype based upon the cross-flow water turbines. The structure has been tested in grid-connected conditions in order to identify the hydrodynamic characteristics of the prime mover and to evaluate the energy efficiency of the overall energy conversion chain. The real-world tests confirm the preliminary conclusion issued from

M. Hauck; A. Rumeau; I. Munteanu; A. I. Bratcu; S. Bacha; D. Roye; A. Hably

2012-01-01

206

Mod-5A wind turbine generator program design report. Volume 4: Drawings and specifications, book 3  

NASA Technical Reports Server (NTRS)

The design, development and analysis of the 7.3 MW MOD-5A wind turbine generator is documented. This volume contains the drawings and specifications developed for the final design. This volume is divided into 5 books of which this is the third, containing drawings 47A380074 through 47A380126. A full breakdown parts listing is provided as well as a where used list.

1984-01-01

207

Modern Practice in the Balancing of Large Turbine-Generator Rotors  

Microsoft Academic Search

In the manufacture of large high-speed turbine-generator rotors, balancing is instrumental in contributing to the over-all performance characteristics of the entire unit. Balancing equipment and instrumentation must be adequate to meet the rigorous demands imposed by shop production requirements. In addition, procedures and techniques must be capable of coping with the various problems that may arise in production balancing. This

C. M. Laffoon; A. C. Hagg; C. H. Janthey; P. R. Heller

1951-01-01

208

Design and analysis of boiler-turbine-generator controls using optimal linear regulator theory  

Microsoft Academic Search

The demand for improved dynamic response of fossil-fired power plants has motivated a comprehensive program of control system design and analysis. Previous papers have reported the development of a nonlinear mathematical model of a drum-type, twin furnace, reheat boiler-turbine-generator (RBTG) system which is suitable for control system analysis and has been extensively verified by field test. On the basis of

J. McDonald; HARRY G. KWATNY

1973-01-01

209

Development of a 40-kilowatt wind-turbine generator. Phase I. Design and analysis. Executive summary  

SciTech Connect

A program to design, fabricate and test a horizontal axis wind turbine generator capable of producing 40 kW electrical output power in a 20 mph wind is discussed. A summary of the results of the Phase I program effort covering design tradeoff studies, preliminary design and analysis, and the final design effort is presented. Additional work covered under Phase I included cost studies and test planning activities.

Howes, H.E.; Bowes, M.A.; Perley, R.

1981-02-01

210

Audible noise from PG and E'S first wind turbine electric generator  

SciTech Connect

On January 15, 1981, the Solano County, California, Planning Commission unanimously approved Pacific Gas and Electric Company's application to demonstrate wind turbine electric generation about 64 kilometers northeast of San Francisco. This action culminated several months of siting study. The siting factor of most concern to the County Planners was the potential for noise impacts on the human environment in the audible and infrasonic ranges strengthened by the MOD-1 Boone Site problems. The action taken to control noise is discussed.

Bush, R.C.

1982-01-01

211

A three-level converter based micro-turbine distributed generation system  

Microsoft Academic Search

This paper proposes a novel converter configuration as a power electronic interface between a high-speed micro-turbine generator and a utility distribution system. The converter system includes a three-level voltage-sourced converter that is connected in a back-to-back configuration to a two-level converter. A space vector modulation based switching strategy is employed to control the converter system. A comprehensive mathematical model is

H. Nikkhajoei; M. Saeedifard; R. Iravani

2006-01-01

212

Control design and performance analysis of a 6 MW wind turbine-generator  

NASA Technical Reports Server (NTRS)

This paper discusses an approach to the modeling and performance for the preliminary design phase of a large (6.2 MW) horizontal axis wind turbine generator (WTG). Two control philosophies are presented, both of which are based on linearized models of the WT mechanical and electrical systems. The control designs are compared by showing the performance through detailed non-linear time simulation. The disturbances considered are wind gusts, and electrical faults near the WT terminals.

Murdoch, A.; Winkelman, J. R.; Javid, S. H.; Barton, R. S.

1983-01-01

213

Basic Studies on Methods of In-Plane Eddy Current Analysis for Stator Core-Ends of Turbine Generators  

NASA Astrophysics Data System (ADS)

In this paper, we investigate the methods of eddy current analysis for stator core-ends of turbine generators from both results of experiment and finite element analysis. First, the 3-D finite element analysis considering the lamination of the core is applied to the simple model that simulates the end part of the turbine generator. The calculated losses and flux distributions caused by the perpendicular flux are compared with the measurement to verify the validity of the calculation method. The measured and calculated results agree well. Next, the calculation method is applied to the 250MVA class turbine generator with the considerations of the laminated stator core. The field and loss distributions at stator core-ends of the turbine generators are clarified.

Yamazaki, Katsumi; Watanabe, Yuta; Tada, Shin; Mogi, Hisashi; Kaido, Chikara; Kanao, Shinichi; Takahashi, Kazuhiko; Ide, Kazumasa; Hattori, Ken'ichi; Nakahara, Akihito

214

The calculation of fluid-structure interaction and fatigue analysis for Francis turbine runner  

NASA Astrophysics Data System (ADS)

Francis turbine, as a widely used hydro turbine, is especially suited for the hydropower station with high hydraulic head and higher hydraulic head. For such turbine generator units all around the world, the crack streaks usually come out after a long time use and the resulted accidents may cause huge losses. Hence, it is meaningful to refine the design assuring the stability and safety of the Francis turbine. In this paper, the stiffness and strength as well as the fatigue life of the Francis turbine are studied. Concerning on the turbine of one certain hydropower station, the flow field inside the turbine are first simulated and the pressure distribution around the blades are derived. Meanwhile, the stress distributions of the blades are also obtained. Based on these, the fatigue analyses are applied on the turbine. According to the results of fatigue analyses, some optimal designs on the turbine are verified. The results show that with the optimal designs, the hydraulic performances of the turbine do not change too much while the maximum stress on the turbine decrease and the fatigue life increase as well.

Wang, X. F.; Li, H. L.; Zhu, F. W.

2012-11-01

215

Integration of permanent magnet synchronous generator wind turbines into power grid  

NASA Astrophysics Data System (ADS)

The world is seeing an ever-increasing demand for electrical energy. The future growth of electrical power generation needs to be a mix of technologies including fossil fuels, hydro, nuclear, wind, and solar. The federal and state energy agencies have taken several proactive steps to increase the share of renewable energy in the total generated electrical power. In 2005, 11.1% of the total 1060 GW electricity generation capacity was from Renewable Energy Sources (RES) in the US. The power capacity portfolio included 9.2% from hydroelectric, 0.87% from wind, and 0.7% from biomass. Other renewable power capacity included 2.8 GW of geothermal, 0.4 GW of solar thermal, and 0.2 GW of solar PV. Although the share of renewable energy sources is small compared with the total power capacity, they are experiencing a high and steady growth. The US is leading the world in wind energy growth with a 27% increase in 2006 and a projected 26% increase in 2007, according to the American Wind Energy Association (AWEA). The US Department of Energy benchmarked a goal to meet 5% of the nation's energy need by launching the Wind Powering America (WPA) program. Although renewable energy sources have many benefits, their utilization in the electrical grid does not come without cost. The higher penetration of RES has introduced many technical and non-technical challenges, including power quality, reliability, safety and protection, load management, grid interconnections and control, new regulations, and grid operation economics. RES such as wind and PV are also intermittent in nature. The energy from these sources is available as long as there is wind or sunlight. However, these are energies that are abundant in the world and the power generated from these sources is pollution free. Due to high price of foundation of wind farms, employing variable speed wind turbines to maximize the extracted energy from blowing wind is more beneficial. On the other hand, since wind power is intermittent, integrating energy storage systems with wind farms has attracted a lot of attention. These two subjects are addressed in this dissertation in detail. Permanent Magnet Synchronous Generators (PMSG) are used in variable speed wind turbines. In this thesis, the dynamic of the PMSG is investigated and a power electronic converter is designed to integrate the wind turbine to the grid. The risks of PMSG wind turbines such as low voltage ride through and short circuits, are assessed and the methods of mitigating the risks are discussed. In the second section of the thesis, various methods of smoothing wind turbine output power are explained and compared. Two novel methods of output power smoothing are analyzed: Rotor inertia and Super capacitors. The advantages and disadvantages of each method are explained and the dynamic model of each method is developed. The performance of the system is evaluated by simulating the wind turbine system in each method. The concepts of the methods of smoothing wind power can be implemented in other types of wind turbines such as Doubly Fed Induction Generator (DFIG) wind turbines.

Abedini, Asghar

216

Wind tower turbine  

Microsoft Academic Search

A wind powered turbine drive for an electric generator is disclosed in which both the generator and the turbine driving it are stationary and remain in a fixed position irrespective of wind direction. This turbine facilitates electric power generation by wind power in those higher power ranges where the greater generator and turbine weights otherwise make it difficult and costly

OHare

1981-01-01

217

Hydro turbine rehab benefits from modeling  

SciTech Connect

The turbine aging process, while seemingly imperceptible, inevitably results in reduced turbine efficiency and capacity. The primary causes of these reductions are runner hydraulic profile changes during weld repairs, surface finish deterioration from cavitation, and runner seal clearance increases due to wear. Many aging turbines require more frequent repairs due to runner cavitation, and wicket gate mechanism, shaft seal, and guide bearing wear. In many instances turbine component repair can be performed in-place. On older units, runner seals, wicket gate bearings, and wicket gate end seals can be repaired only when the turbine is disassembled. Since the significant cost to disassemble and overhaul units must be offset by future maintenance savings and generation increases, turbine rehabilitation is often postponed as owners consider other alternatives. Rehabilitation is a general term used to describe a wide range of turbine reconditioning and design alternatives. Turbine rehabilitation can include a major overhaul of components, runner replacement, and component modifications. Deteriorated runners can be replaced with either a new identical runner or a new modern design having increased efficiency and capacity. The comparative turbine performance of an original, existing, and a modern runner design are shown in this paper. Component overhauls can extend turbine life and restore original efficiency and capacity to existing units. However, the overhaul of existing components cannot increase plant capacity and generation above the as-new values. As a result, owners of aging plants are considering the benefits of replacing existing turbines with modern, more efficient, higher capacity turbines, or expanding the sites. Where expansion is not feasible, hydroelectric power plant owners are finding that turbine rehabilitation is the most cost-effective method to increase plant value and life.

Froehlich, D.R.; Veatch, J.A. (Black and Veatch (US))

1991-01-01

218

DESIGN, FABRICATION, AND TESTING OF AN ADVANCED, NON-POLLUTING TURBINE DRIVE GAS GENERATOR  

SciTech Connect

The objectives of this report period were to continue the development of the Gas Generator design, to complete the hardware and ancillary hardware fabrication, and commence the Test Preparations for the testing of the non-polluting unique power turbine drive gas generator. Focus during this report period has been on testing the Gas Generator. Because of unacceptable delays encountered in a previously competitively selected test site, CES initiated a re-competition of our testing program and selected an alternate test site. Following that selection, CES used all available resources to make preparations for testing the 10 Mw Gas Generator at the new testing site facilities of NTS at Saugus, CA. A substantial portion of this report period was devoted to Testing Preparations, i.e. test facility development, cold- flow testing, calibration testing, performing igniter ignition testing, and then commencement of the completely assembled Gas Generator Assembly Testing, in process at this writing.

Unknown

2001-10-30

219

DESIGN, FABRICATION, AND TESTING OF AN ADVANCED, NON-POLLUTING TURBINE DRIVE GAS GENERATOR  

SciTech Connect

The objectives of this report period were to complete the development of the Gas Generator design, which was done; fabricate and test of the non-polluting unique power turbine drive gas Gas Generator, which has been postponed. Focus during this report period has been to complete the brazing and bonding necessary to fabricate the Gas Generator hardware, continue making preparations for fabricating and testing the Gas Generator, and continuing the fabrication of the Gas Generator hardware and ancillary hardware in preparation for the test program. Fabrication is more than 95% complete and is expected to conclude in early May 2002. the test schedule was affected by relocation of the testing to another test supplier. The target test date for hot fire testing is now not earlier than June 15, 2002.

Unknown

2002-03-31

220

Measurement and prediction of broadband noise from large horizontal axis wind turbine generators  

NASA Technical Reports Server (NTRS)

A method is presented for predicting the broadband noise spectra of large wind turbine generators. It includes contributions from such noise sources as the inflow turbulence to the rotor, the interactions between the turbulent boundary layers on the blade surfaces with their trailing edges and the wake due to a blunt trailing edge. The method is partly empirical and is based on acoustic measurements of large wind turbines and airfoil models. Spectra are predicted for several large machines including the proposed MOD-5B. Measured data are presented for the MOD-2, the WTS-4, the MOD-OA, and the U.S. Windpower Inc. machines. Good agreement is shown between the predicted and measured far field noise spectra.

Grosveld, F. W.; Shepherd, K. P.; Hubbard, H. H.

1995-01-01

221

Employing static excitation control and tie line reactance to stabilize wind turbine generators  

NASA Technical Reports Server (NTRS)

An analytical representation of a wind turbine generator is presented which employs blade pitch angle feedback control. A mathematical model was formulated. With the functioning MOD-0 wind turbine serving as a practical case study, results of computer simulations of the model as applied to the problem of dynamic stability at rated load are also presented. The effect of the tower shadow was included in the input to the system. Different configurations of the drive train, and optimal values of the tie line reactance were used in the simulations. Computer results revealed that a static excitation control system coupled with optimal values of the tie line reactance would effectively reduce oscillations of the power output, without the use of a slip clutch.

Hwang, H. H.; Mozeico, H. V.; Guo, T.

1978-01-01

222

Performance augmentation with vortex generators: Design and testing for stall-regulated AWT-26 turbine  

SciTech Connect

A study investigated the use of vortex generators (VGs) for performance augmentation of the stall-regulated AWT-26 wind turbine. Based on wind-tunnel results and analysis, a VG array was designed for and tested on the AWT-26 prototype, designated Pt. Performance and loads data were measured for P1, both with and without VGs installed. The turbine performance with VGs met most of the design requirements; power output was increased at moderate wind speeds with a minimal effect on peak power. However, VG drag penalties caused a loss in power output for low wind speeds, such that performance with VGs resulted in a net decrease in AEP for wind speed sites up to 8.5 m/s. 8 refs., 8 figs., 3 tabs.

Griffin, D.A. [Advanced Wind Turbines Inc., Seattle, WA (United States)

1996-12-31

223

Neural Network Based Modeling of a Large Steam Turbine-Generator Rotor Body Parameters from On-Line Disturbance Data  

E-print Network

- nous generator. In this study, disturbance data sets acquired on-line at differ- ent loading data. Therefore, no apriori knowledge of the shape of the mapping is required. The effects of generatorNeural Network Based Modeling of a Large Steam Turbine-Generator Rotor Body Parameters from On

224

DESIGN, FABRICATION, AND TESTING OF AN ADVANCED, NON-POLLUTING TURBINE DRIVE GAS GENERATOR  

SciTech Connect

The objective of this report period was to continue the development of the Gas Generator design, completion of the hardware and ancillary hardware fabrication and commence the Test Preparations for the testing of the non-polluting unique power turbine driven Gas Generator. Focus during this report period has been on completing the Gas Generator fabrication of hardware and ancillary hardware, and completion of unit closeout brazing and bonding. Because of unacceptable delays encountered in a previously competitively selected test site, CES initiated a re-competition of our testing program and selected an alternate test site. Following that selection, CES used all available resources to make preparations for testing the 10 Mw Gas Generator at the new testing site facilities of NTS at Saugus, CA.

E.W. (Gene) Baxter

2002-06-30

225

Strategies for Refining IEC 61400-2: Wind Turbine Generator Systems - Part 2: Safety of Small Wind Turbines: Preprint  

Microsoft Academic Search

This paper provides a status of the changes currently being made by IEC Maintenance Team 02 (MT02) to the existing IEC 61400-2 ''Safety of small wind turbines.'' In relation to the work done by IEC MT02, work has been done by NREL and Windward Engineering under the DOE\\/NREL Small Wind Turbine (SWT) Project. Aeroelastic models were built and measurements taken

J. J. D. van Dam; T. L. Forsyth; A. C. Hansen

2001-01-01

226

Analysis of the electrical harmonic characteristics of a slip recovery variable speed generating system for wind turbine applications  

NASA Astrophysics Data System (ADS)

Variable speed electric generating technology can enhance the general use of wind energy in electric utility applications. This enhancement results from two characteristic properties of variable speed wind turbine generators: an improvement in drive train damping characteristics, which results in reduced structural loading on the entire wind turbine system, and an improvement in the overall efficiency by using a more sophisticated electrical generator. Electronic converter systems are the focus of this investigation -- in particular, the properties of a wound-rotor induction generator with the slip recovery system and direct-current link converter. Experience with solid-state converter systems in large wind turbines is extremely limited. This report presents measurements of electrical performances of the slip recovery system and is limited to the terminal characteristics of the system. Variable speed generating systems working effectively in utility applications will require a satisfactory interface between the turbine/generator pair and the utility network. The electrical testing described herein focuses largely on the interface characteristics of the generating system. A MOD-O wind turbine was connected to a very strong system; thus, the voltage distortion was low and the total harmonic distortion in the utility voltage was less than 3 percent (within the 5 percent limit required by most utilities). The largest voltage component of a frequency below 60 Hz was 40 dB down from the 60-Hz less than component.

Herrera, J. I.; Reddoch, T. W.

1988-02-01

227

14 CFR 33.72 - Hydraulic actuating systems.  

Code of Federal Regulations, 2010 CFR

... 2010-01-01 2010-01-01 false Hydraulic actuating systems. 33.72 Section 33...Construction; Turbine Aircraft Engines § 33.72 Hydraulic actuating systems. Each hydraulic actuating system must function...

2010-01-01

228

Wind Turbine Generator System Duration Test Report for the Gaia-Wind 11 kW Wind Turbine  

SciTech Connect

This test was conducted as part of the U.S. Department of Energy's (DOE) Independent Testing project. This project was established to help reduce the barriers of wind energy expansion by providing independent testing results for small turbines. In total, five turbines are being tested at the National Renewable Energy Laboratory's (NRELs) National Wind Technology Center (NWTC) as a part of this project. Duration testing is one of up to five tests that may be performed on the turbines, including power performance, safety and function, noise, and power quality tests. The results of the testing will provide the manufacturers with reports that may be used for small wind turbine certification. The test equipment includes a Gaia-Wind 11 kW wind turbine mounted on an 18 m monopole tower. Gaia-Wind Ltd. manufactured the turbine in Denmark, although the company is based in Scotland. The system was installed by the NWTC Site Operations group with guidance and assistance from Gaia-Wind.

Huskey, A.; Bowen, A.; Jager, D.

2010-09-01

229

Development and testing of vortex generators for small horizontal axis wind turbines  

NASA Technical Reports Server (NTRS)

Vortex generators (VGs) for a small (32 ft diameter) horizontal axis wind turbine, the Carter Model 25, have been developed and tested. Arrays of VGs in a counterrotating arrangement were tested on the inbound half-span, outboard half-span, and on the entire blade. VG pairs had their centerlines spaced at a distance of 15% of blade chord, with a spanwise width of 10% of blade chord. Each VG had a length/height ratio of 4, with a height of between 0.5% and 1.0% of the blade chord. Tests were made with roughness strips to determine whether VGs alleviated the sensitivity of some turbines to an accumulation of bugs and dirt on the leading edge. Field test data showed that VGs increased power output up to 20% at wind speeds above 10 m/s with only a small (less than 4%) performance penalty at lower speeds. The VGs on the outboard span of the blade were more effective than those on inner sections. For the case of full span coverage, the energy yearly output increased almost 6% at a site with a mean wind speed of 16 mph. The VGs did reduce the performance loss caused by leading edge roughness. An increase in blade pitch angle has an effect on the power curve similar to the addition of VGs. VGs alleviate the sensitivity of wind turbine rotors to leading edge roughness caused by bugs and drift.

Gyatt, G. W.

1986-01-01

230

FABRICATE AND TEST AN ADVANCED NON-POLLUTING TURBINE DRIVE GAS GENERATOR  

SciTech Connect

In September 2000 the Department of Energy's National Energy Technology Laboratory (DOE/NETL) contracted with Clean Energy Systems, Inc. (CES) of Sacramento, California to design, fabricate, and test a 20 MW{sub t} (10 MW{sub e}) gas generator. Program goals were to demonstrate a non-polluting gas generator at temperatures up to 3000 F at 1500 psi, and to demonstrate resulting drive gas composition, comprising steam and carbon dioxide substantially free of pollutants. Following hardware design and fabrication, testing, originally planned to begin in the summer of 2001, was delayed by unavailability of the contracted test facility. CES designed, fabricated, and tested the proposed gas generator as originally agreed. The CES process for producing near-zero-emissions power from fossil fuels is based on the near-stoichiometric combustion of a clean gaseous fuel with oxygen in the presence of recycled water, to produce a high-temperature, high-pressure turbine drive fluid comprising steam and carbon dioxide. Tests demonstrated igniter operation over the prescribed ranges of pressure and mixture ratios. Ignition was repeatable and reliable through more than 100 ignitions. Injector design ''A'' was operated successfully at both low power ({approx}20% of rated power) and at rated power ({approx}20 MW{sub t}) in more than 95 tests. The uncooled gas generator configuration (no diluent injectors or cooldown chambers installed) produced drive gases at temperatures approaching 3000 F and at pressures greater than 1550 psia. The fully cooled gas generator configuration, with cooldown chambers and injector ''A'', operated consistently at pressures from 1100 to 1540 psia and produced high pressure, steam-rich turbine drive gases at temperatures ranging from {approx}3000 to as low as 600 F. This report includes description of the intended next steps in the gas generator technology demonstration and traces the anticipated pathway to commercialization for the gas generator technology developed in this program.

Eugene Baxter; Roger E. Anderson; Stephen E. Doyle

2003-06-01

231

Analytical investigation of thermal barrier coatings for advanced power generation combustion turbines  

NASA Technical Reports Server (NTRS)

An analytical evaluation was conducted to determine quantitatively the improvement potential in cycle efficiency and cost of electricity made possible by the introduction of thermal barrier coatings to power generation combustion turbine systems. The thermal barrier system, a metallic bond coat and yttria stabilized zirconia outer layer applied by plasma spray techniques, acts as a heat insulator to provide substantial metal temperature reductions below that of the exposed thermal barrier surface. The study results show the thermal barrier to be a potentially attractive means for improving performance and reducing cost of electricity for the simple, recuperated, and combined cycles evaluated.

Amos, D. J.

1977-01-01

232

Development of a 40-kilowatt wind turbine generator. Phase I: design and analysis  

SciTech Connect

Kaman Aerospace Corporation is currently engaged in a program to design, fabricate and test a horizontal axis wind turbine generator capable of producing 40 kW electrical output power in a 20 mph wind. This report presents the results of the Phase I program effort covering design tradeoff studies, preliminary design and analysis, and the final design effort. Additional work covered under Phase I included cost studies and test planning activities. The program is currently in the Contractor test stage of Phase II.

Howes, H.E.; Bowes, M.A.; Perley, R.

1981-02-01

233

Computer-assisted planning and technical direction of turbine generator outages  

SciTech Connect

The changing management and personnel environments in power utility companies, as well as the need for greater cost savings and ways to shorten maintenance outage time, have created a need for computer-assisted planning and documentation programs. To meet this need, a software tool is under development--Total Outage Planning Software (TOPS)--that will assist the planning and technical direction of turbine generator outages. This powerful, yet user-friendly software runs in Windows on a desktop or laptop personal computer. TOPS takes advantage of the mass data storage available with compact disc (CD) technology by archiving the complete outage documentation on CD. Previous outage records can then be indexed, searched, and viewed on a computer with the click of a mouse. Critical-path schedules, parts lists, parts order tracking, work instructions and procedures, custom data sheets, and progress reports can be generated by computer on site during an outage. After the initial documented outage, customized data sheet templates, drawing indexes, work scopes, contractor and vendor listings, schedules, man-hour cost estimations, previous repair documentation, and previous inspection documentation will be available for use during future outages. TOPS will increase future turbine generator outage quality and efficiency for the same unit or sister units of the same make and similar size. TOPS will also provide utilities with more independent control over outages. Furthermore, reliance on sometimes biased and often high-priced OEM maintenance services will be dramatically reduced.

Dove, B.W.; Reinhart, E.R. [Reinhart and Associates, Inc., Austin, TX (United States)

1996-12-31

234

MOD-0A 200 kW wind turbine generator design and analysis report  

NASA Astrophysics Data System (ADS)

The design, analysis, and initial performance of the MOD-OA 200 kW wind turbine generator at Clayton, NM is documented. The MOD-OA was designed and built to obtain operation and performance data and experience in utility environments. The project requirements, approach, system description, design requirements, design, analysis, system tests, installation, safety considerations, failure modes and effects analysis, data acquisition, and initial performance for the wind turbine are discussed. The design and analysis of the rotor, drive train, nacelle equipment, yaw drive mechanism and brake, tower, foundation, electricl system, and control systems are presented. The rotor includes the blades, hub, and pitch change mechanism. The drive train includes the low speed shaft, speed increaser, high speed shaft, and rotor brake. The electrical system includes the generator, switchgear, transformer, and utility connection. The control systems are the blade pitch, yaw, and generator control, and the safety system. Manual, automatic, and remote control are discussed. Systems analyses on dynamic loads and fatigue are presented.

Anderson, T. S.; Bodenschatz, C. A.; Eggers, A. G.; Hughes, P. S.; Lampe, R. F.; Lipner, M. H.; Schornhorst, J. R.

1980-08-01

235

A preliminary study of power generation from vertical-axis turbines in the Gulf Stream  

NASA Astrophysics Data System (ADS)

A system consisting of paired, vertical axis turbines suspended from a tethered, buoyant, submerged platform that contains the generator is proposed as a method for power generation from the Gulf Stream. Drilled piles are the most likely kind of mooring system for the holding capacity needed. Successful extraction of electrical energy from the Gulf Stream requires consideration of the environment, as well as its effects on potential materials and surface features of the power generating system. Because of its topography, the region called the Straits of Florida contains the fastest flowing water masses (known as the Florida Current) found in the Gulf Stream system. The warm, fast flowing, deep, salty water contains myriad life forms, and presents a highly corrosive environment to most common building materials. The minimization of galvanic and crevice types of corrosion offers the most formidable challenge to the designer.

Carnicom, M. L.; Sheldahl, R. E.

1981-01-01

236

The MOD-OA 200 kilowatt wind turbine generator design and analysis report  

NASA Technical Reports Server (NTRS)

The project requirements, approach, system description, design requirements, design, analysis, system tests, installation safety considerations, failure modes and effects analysis, data acquisition, and initial performance for the MOD-OA 200 kw wind turbine generator are discussed. The components, the rotor, driven train, nacelle equipment, yaw drive mechanism and brake, tower, foundation, electrical system, and control systems are presented. The rotor includes the blades, hub and pitch change mechanism. The drive train includes the low speed shaft, speed increaser, high speed shaft, and rotor brake. The electrical system includes the generator, switchgear, transformer, and utility connection. The control systems are the blade pitch, yaw, and generator control, and the safety system. Manual, automatic, and remote control and Dynamic loads and fatigue are analyzed.

Andersen, T. S.; Bodenschatz, C. A.; Eggers, A. G.; Hughes, P. S.; Lampe, R. F.; Lipner, M. H.; Schornhorst, J. R.

1980-01-01

237

EEMD-based wind turbine bearing failure detection using the generator stator current homopolar component  

NASA Astrophysics Data System (ADS)

Failure detection has always been a demanding task in the electrical machines community; it has become more challenging in wind energy conversion systems because sustainability and viability of wind farms are highly dependent on the reduction of the operational and maintenance costs. Indeed the most efficient way of reducing these costs would be to continuously monitor the condition of these systems. This allows for early detection of the generator health degeneration, facilitating a proactive response, minimizing downtime, and maximizing productivity. This paper provides then an assessment of a failure detection techniques based on the homopolar component of the generator stator current and attempts to highlight the use of the ensemble empirical mode decomposition as a tool for failure detection in wind turbine generators for stationary and non-stationary cases.

Amirat, Yassine; Choqueuse, Vincent; Benbouzid, Mohamed

2013-12-01

238

Aerodynamic effects on TLP type wind turbines and predictions of the electricity they generate  

NASA Astrophysics Data System (ADS)

This research proposes a new offshore wind energy generation system that uses a tension leg platform (TLP) and describes experiments performed on a TLP type wind turbine in both waves and wind. The following conclusions can be made from the results of this research. 1) In the case of coexisting wave-wind fields, the wind effect stabilizes the pitch motion. 2) The wind effect decreases vibration of the mooring lines when waves and wind coexist. In particular, the springing (2nd or 3rd order force) also decreases in this field. 3) It can be estimated that the reduction in the rate of generation of electrical power can be up to about 6% as a result of the heel angle. In addition, the annual amount of electricity generated was estimated along with the utilization factor based on the experimental results.

Nihei, Yasunori; Fujioka, Hiroyuki

2011-06-01

239

The MOD-OA 200 kilowatt wind turbine generator design and analysis report  

NASA Astrophysics Data System (ADS)

The project requirements, approach, system description, design requirements, design, analysis, system tests, installation safety considerations, failure modes and effects analysis, data acquisition, and initial performance for the MOD-OA 200 kw wind turbine generator are discussed. The components, the rotor, driven train, nacelle equipment, yaw drive mechanism and brake, tower, foundation, electrical system, and control systems are presented. The rotor includes the blades, hub and pitch change mechanism. The drive train includes the low speed shaft, speed increaser, high speed shaft, and rotor brake. The electrical system includes the generator, switchgear, transformer, and utility connection. The control systems are the blade pitch, yaw, and generator control, and the safety system. Manual, automatic, and remote control and Dynamic loads and fatigue are analyzed.

Andersen, T. S.; Bodenschatz, C. A.; Eggers, A. G.; Hughes, P. S.; Lampe, R. F.; Lipner, M. H.; Schornhorst, J. R.

1980-08-01

240

Wind turbine generators having wind assisted cooling systems and cooling methods  

DOEpatents

A wind generator includes: a nacelle; a hub carried by the nacelle and including at least a pair of wind turbine blades; and an electricity producing generator including a stator and a rotor carried by the nacelle. The rotor is connected to the hub and rotatable in response to wind acting on the blades to rotate the rotor relative to the stator to generate electricity. A cooling system is carried by the nacelle and includes at least one ambient air inlet port opening through a surface of the nacelle downstream of the hub and blades, and a duct for flowing air from the inlet port in a generally upstream direction toward the hub and in cooling relation to the stator.

Bagepalli, Bharat (Niskayuna, NY); Barnes, Gary R. (Delanson, NY); Gadre, Aniruddha D. (Rexford, NY); Jansen, Patrick L. (Scotia, NY); Bouchard, Jr., Charles G. (Schenectady, NY); Jarczynski, Emil D. (Scotia, NY); Garg, Jivtesh (Cambridge, MA)

2008-09-23

241

Dispersion analysis of passive surface-wave noise generated during hydraulic-fracturing operations  

NASA Astrophysics Data System (ADS)

Surface-wave dispersion analysis is useful for estimating near-surface shear-wave velocity models, designing receiver arrays, and suppressing surface waves. Here, we analyze whether passive seismic noise generated during hydraulic-fracturing operations can be used to extract surface-wave dispersion characteristics. Applying seismic interferometry to noise measurements, we extract surface waves by cross-correlating several minutes of passive records; this approach is distinct from previous studies that used hours or days of passive records for cross-correlation. For comparison, we also perform dispersion analysis for an active-source array that has some receivers in common with the passive array. The active and passive data show good agreement in the dispersive character of the fundamental-mode surface-waves. For the higher mode surface waves, however, active and passive data resolve the dispersive properties at different frequency ranges. To demonstrate an application of dispersion analysis, we invert the observed surface-wave dispersion characteristics to determine the near-surface, one-dimensional shear-wave velocity.

Forghani-Arani, Farnoush; Willis, Mark; Snieder, Roel; Haines, Seth S.; Behura, Jyoti; Batzle, Mike; Davidson, Michael

2014-12-01

242

Proposal and Development of Radial Air-gap Coreless Generator Suitable for Small Wind Turbine using in Urban Area  

NASA Astrophysics Data System (ADS)

Independent distributed generations using small wind turbines are widely spread as increasing of wind power generation. Installation of small wind turbines in densely-populated urban area is not only useful from the viewpoint of digging up wind power source in weak-wind area but also for enlightenment of renewable energy due to closing power supplies to consumptions. From the point of view, the authors proposed “urban wind power generation" using collective system with a number of small vertical wind turbines and have developed a suitable generator for low-speed vertical wind turbines such as Savonius windmill. Standardized on a coreless generator, the proposed generator is designed to let direction of magnetic fluxes radial in order to install the magnets and coils on the outer end of the generator. The change of magnet composition and flux direction gives realization of maximized speed of flux change and output voltage in the limited space. With above composition, the power of the proposed one is independent on the diameter. In this report, we describe evaluated fundamental performance of a prototype of the proposed generator. As the result of the experiments, the maximum output power of 283W was obtained. The obtained starting torque is enough small to begin to rotate at weak wind condition of no more than 1m/s. Therefore, it is clear that the proposed “radial” coreless generator is suitable for self-starting and producing high power at low speed wind.

Takahashi, Toshiyuki; Yasuda, Yoh; Ohmoto, Shingo; Hara, Takehisa

243

Variable speed generator application on the MOD-5A 7.3 mW wind turbine generator  

NASA Astrophysics Data System (ADS)

This paper describes the application of a Scherbiustat type variable speed subsystem in the MOD-5A Wind Turbine Generator. As designed by General Electric Company, Advanced Energy Programs Department, under contract DEN3-153 with NASA Lewis Research Center and DOE, the MOD-5A utilizes the subsystem for both starting assistance in a motoring mode and generation in a controlled airgap torque mode. Reactive power control is also provided. The Scherbiustat type arrangement of a wound rotor machine with a cycloconverter in the rotor circuit was selected after an evaluation of variable speed technologies that followed a system evaluation of drivetrain cost and risk. The paper describes the evaluation factors considered, the results of the evaluations and summarizes operating strategy and performance simulations.

Barton, Robert S.

1995-05-01

244

Variable speed generator application on the MOD-5A 7.3 mW wind turbine generator  

NASA Technical Reports Server (NTRS)

This paper describes the application of a Scherbiustat type variable speed subsystem in the MOD-5A Wind Turbine Generator. As designed by General Electric Company, Advanced Energy Programs Department, under contract DEN3-153 with NASA Lewis Research Center and DOE, the MOD-5A utilizes the subsystem for both starting assistance in a motoring mode and generation in a controlled airgap torque mode. Reactive power control is also provided. The Scherbiustat type arrangement of a wound rotor machine with a cycloconverter in the rotor circuit was selected after an evaluation of variable speed technologies that followed a system evaluation of drivetrain cost and risk. The paper describes the evaluation factors considered, the results of the evaluations and summarizes operating strategy and performance simulations.

Barton, Robert S.

1995-01-01

245

Mod-5A wind turbine generator program design report. Volume 2: Conceptual and preliminary design, book 2  

NASA Technical Reports Server (NTRS)

The design, development and analysis of the 7.3 MW MOD-5A wind tunnel generator is documented. There are four volumes. In Volume 2, book 2 the requirements and criteria for the design are presented. The development tests, which determined or characterized many of the materials and components of the wind turbine generator, are described.

1984-01-01

246

Turbine-Generator Shaft Torques and Fatigue: Part II - Impact of System Distribances and High Speed Reclosure  

Microsoft Academic Search

This paper is the second of two papers concerned with the effects of power system disturbances and operating practices upon turbine-generator shafts. This paper presents the results of various simulations for which the type of disturbance and the resulting generator shaft torsional oscillations are correlated with potential loss of life to the shaft system, using techniques described in the companion

R. D. Dunlop; S. H. Horowitz; A. C. Parikh; M. C. Jackson; S. D. Umans

1979-01-01

247

202 IEEE TRANS.4CTIONS Oh'AUTOMATIC CONTROL, VOL. AC-18,NO. 3, J U K E 1973 Design and Analysis of Boiler-Turbine-Generator  

E-print Network

of Boiler-Turbine-Generator Controls Using Optimal Linear Regulator Theory JOHN P. McDOKALD AND HARRY G of a nonlinear mathematical model of a drum-type, twin furnace, reheat boiler-turbine-generator (RBTG) system- tiveoperatingandcontrolstrategies for boiler-t.urbine- generator systems to meet different, system operating ob- jectives. Among

Kwatny, Harry G.

248

Turbine modeling technique to generate off-design performance data for both single and multistage axial-flow turbines  

NASA Technical Reports Server (NTRS)

This technique is applicable to larger axial flow turbines which may or may not incorporate variable geometry in the first stage stator. A user specified option will also permit the calculation of design point cooling flow levels and the corresponding change in turbine efficiency. The modeling technique was incorporated into a time sharing computer program in order to facilitate its use. Because this report contains a description of the input output data, values of typical inputs, and example cases, it is suitable as a user's manual.

Converse, G. L.

1981-01-01

249

ARE660 Wind Generator: Low Wind Speed Technology for Small Turbine Development  

SciTech Connect

This project is for the design of a wind turbine that can generate most or all of the net energy required for homes and small businesses in moderately windy areas. The purpose is to expand the current market for residential wind generators by providing cost effective power in a lower wind regime than current technology has made available, as well as reduce noise and improve reliability and safety. Robert W. Preus’ experience designing and/or maintaining residential wind generators of many configurations helped identify the need for an improved experience of safety for the consumer. Current small wind products have unreliable or no method of stopping the wind generator in fault or high wind conditions. Consumers and their neighbors do not want to hear their wind generators. In addition, with current technology, only sites with unusually high wind speeds provide payback times that are acceptable for the on-grid user. Abundant Renewable Energy’s (ARE) basic original concept for the ARE660 was a combination of a stall controlled variable speed small wind generator and automatic fail safe furling for shutdown. The stall control for a small wind generator is not novel, but has not been developed for a variable speed application with a permanent magnet alternator (PMA). The fail safe furling approach for shutdown has not been used to our knowledge.

Robert W. Preus; DOE Project Officer - Keith Bennett

2008-04-23

250

Measured effects of wind turbine generation at the Block Island Power Company  

NASA Technical Reports Server (NTRS)

Data measurements made on the NASA MOD-OA 200-kw wind-turbine generator (WTG) installed on a utility grid form the basis for an overall performance analysis. Fuel displacement/-savings, dynamic interactions, and WTG excitation (reactive-power) control effects are studied. Continuous recording of a large number of electrical and mechanical variables on FM magnetic tape permit evaluation and correlation of phenomena over a bandwidth of at least 20 Hz. Because the wind-power penetration reached peaks of 60 percent, the impact of wind fluctuation and wind-turbine/diesel-utility interaction is evaluated in a worst-case scenario. The speed-governor dynamics of the diesel units exhibited an underdamped response, and the utility operation procedures were not altered to optimize overall WTG/utility performance. Primary findings over the data collection period are: a calculated 6.7-percent reduction in fuel consumption while generating 11 percent of the total electrical energy; acceptable system voltage and frequency fluctuations with WTG connected; and applicability of WTG excitation schemes using voltage, power, or VARS as the controlled variable.

Wilreker, V. F.; Smith, R. F.; Stiller, P. H.; Scot, G. W.; Shaltens, R. K.

1984-01-01

251

The New Generation of Oils for the Hydraulic Systems of Industrial Equipment  

Microsoft Academic Search

The state of industrial oil production in 2001 is examined. The characteristics of modern series I–G–S(d) hydraulic oils with improved filterability and the conditions required for their production are reported.

L. A. Radchenko; A. A. Chesnokov

2003-01-01

252

Wind Turbine Generator System Power Performance Test Report for the Gaia-Wind 11-kW Wind Turbine  

SciTech Connect

This test was conducted as part of the U.S. Department of Energy's (DOE) Independent Testing project. It is a power performance test that the National Renewable Energy Laboratory (NREL) conducted on the Gaia-Wind 11-kW small wind turbine.

Huskey, A.; Bowen, A.; Jager, D.

2009-12-01

253

Endwall shape modification using vortex generators and fences to improve gas turbine cooling and effectiveness  

NASA Astrophysics Data System (ADS)

The gas turbine is one of the most important parts of the air-breathing jet engine. Hence, improving its efficiency and rendering it operable under high temperatures are constant goals for the aerospace industry. Two types of flow within the gas turbine are of critical relevance: The flow around the first row of stator blades (also known as the nozzle guide vane blade - NGV) and the cooling flow inside the turbine blade cooling channel. The subject of this thesis work was to search for methods that could improve the characteristics of these two types of flows, thus enabling superior engine performance. The innovative aspect of our work was to apply an endwall shape modification previously employed by non-aerospace industries for cooling applications, to the gas turbine cooling flow which is vital to aerospace propulsion. Since the costs of investigating the possible benefits of any idea via extensive experiments could be quite high, we decided to use computational fluid dynamics (CFD) followed by experimentation as our methodology. We decided to analyze the potential benefits of using vortex generators (VGs) as well as the rectangular endwall fence. Since the pin-fins used in cooling flow are circular cylinders, and since the boundary layer flow is mainly characterized by the leading edge diameter of the NGV blade, we modeled both the pin-fins and the NGV blade as vertical circular cylinders. The baseline case consisted of the cylinder(s) being subjected to cross flow and a certain amount of freestream turbulence. The modifications we made on the endwall consisted of rectangular fences. In the case of the cooling flow, we used triangular shaped, common flow up oriented, delta winglet type vortex generators as well as rectangular endwall fences. The channel contained singular cylinders as well as staggered rows of multiple cylinders. For the NGV flow, a rectangular endwall fence and a singular cylinder were utilized. Using extensive CFD modeling and analysis, we confirmed that placing a rectangular endwall fence upstream of the cylinder created additional turbulent mixing in the domain. This led to increased mixing of the cooler flow in the freestream and the hotter flow near the endwall. As a result, we showed that adding a rectangular fence created a 10% mean heat transfer increase downstream of the cylinder. When vortex generators are used, as the flow passes over the sharp edges of the vortex generators, it separates and continues downstream in a rolling, helical pattern. Combined with the effect generated by the orientation of the vortex generators, this flow structure mixes the higher momentum fluid in the freestream with lower momentum fluid in the boundary layer. Similar turbulent mixing behavior is observed over the entire domain, near the cylinders and the side walls. As a result, the heat transfer levels over the wall surfaces are increased and improved cooling is achieved. The improvements in heat transfer are obtained at the expense of acceptable pressure losses across the cooling channel. When the vortex generators are used, the CFD modeling studies showed that overall heat transfer improvements as high as 27% compared to the baseline case are observed inside a domain containing multiple rows of cylinders. A price in the form of 13% pressure loss increase across the channel is paid for the heat transfer benefits. Experiments conducted in the open loop wind tunnel of the Turbomachinery Aero-Heat Transfer Laboratory of the Department of Aerospace Engineering of Penn State University supported the general positive trend of these findings, with a 14% overall increase in heat transfer over the constant heat flux surface when vortex generators are installed, accompanied by an 8% increase in pressure loss. (Abstract shortened by UMI.)

Gokce, Zeki Ozgur

254

Fluid power network for centralized electricity generation in offshore wind farms  

NASA Astrophysics Data System (ADS)

An innovative and completely different wind-energy conversion system is studied where a centralized electricity generation within a wind farm is proposed by means of a hydraulic network. This paper presents the dynamic interaction of two turbines when they are coupled to the same hydraulic network. Due to the stochastic nature of the wind and wake interaction effects between turbines, the operating parameters (i.e. pitch angle, rotor speed) of each turbine are different. Time domain simulations, including the main turbine dynamics and laminar transient flow in pipelines, are used to evaluate the efficiency and rotor speed stability of the hydraulic system. It is shown that a passive control of the rotor speed, as proposed in previous work for a single hydraulic turbine, has strong limitations in terms of performance for more than one turbine coupled to the same hydraulic network. It is concluded that in order to connect several turbines, a passive control strategy of the rotor speed is not sufficient and a hydraulic network with constant pressure is suggested. However, a constant pressure network requires the addition of active control at the hydraulic motors and spear valves, increasing the complexity of the initial concept. Further work needs to be done to incorporate an active control strategy and evaluate the feasibility of the constant pressure hydraulic network.

Jarquin-Laguna, A.

2014-06-01

255

Development of a High Pressure/High Temperature Down-hole Turbine Generator  

SciTech Connect

As oil & natural gas deposits become more difficult to obtain by conventional means, wells must extend to deeper more heat-intensive environments. The technology of the drilling equipment required to reach these depths has exceeded the availability of electrical power sources needed to operate these tools. Historically, logging while drilling (LWD) and measure while drilling (MWD) devices utilized a wireline to supply power and communication from the operator to the tool. Lithium ion batteries were used in scenarios where a wireline was not an option, as it complicated operations. In current downhole applications, lithium ion battery (LIB) packs are the primary source for electrical power. LIB technology has been proven to supply reliable downhole power at temperatures up to 175 °C. Many of the deeper well s reach ambient temperatures above 200 °C, creating an environment too harsh for current LIB technology. Other downfalls of LIB technology are cost, limitations on charge cycles, disposal issues and possible safety hazards including explosions and fires. Downhole power generation can also be achieved by utilizing drilling fluid flow and converting it to rotational motion. This rotational motion can be harnessed to spin magnets around a series of windings to produce power proportional to the rpm experienced by the driven assembly. These generators are, in most instances, driven by turbine blades or moyno-based drilling fluid pumps. To date, no commercially available downhole power generators are capable of operating at ambient temperatures of 250 °C. A downhole power g enerator capable of operation in a 250 °C and 20,000 psi ambient environment will be an absolute necessity in the future. Dexter Magnetic Technologies’ High-Pressure High-Temperature (HPHT) Downhole Turbine Generator is capable of operating at 250 °C and 20, 000 psi, but has not been tested in an actual drilling application. The technology exists, but to date no company has been willing to test the tool.

Ben Plamp

2008-06-30

256

Hydraulic waste energy recovery, Phase 2. A technical report  

SciTech Connect

The energy required for booster station operation is supplied by the electrical utility company and has an associated cost. Energy removed by pressure reducing valves in the system is lost or wasted. The objective of this project is to capture the wasted hydraulic energy with in-line turbines. In this application, the in-line turbines act as pressure reducing valves while removing energy from the water distribution system and converting it to electrical energy. The North Service Center pumping station was selected for the pilot program due to the availability of a wide range in pressure drop and flow, which are necessary for hydraulic energy recovery. The research performed during this project resulted in documentation of technical, economic, installation, and operational information necessary for local government officials to make an informed judgement as it relates to in-line turbine generation.

Not Available

1992-02-01

257

Steam Turbines  

NASA Technical Reports Server (NTRS)

Turbonetics Energy, Inc.'s steam turbines are used as power generating systems in the oil and gas, chemical, pharmaceuticals, metals and mining, and pulp and paper industries. The Turbonetics line benefited from use of NASA research data on radial inflow steam turbines and from company contact with personnel of Lewis Research Center, also use of Lewis-developed computer programs to determine performance characteristics of turbines.

1981-01-01

258

The Effect of Mounting Vortex Generators on the DTU 10MW Reference Wind Turbine Blade  

NASA Astrophysics Data System (ADS)

The aim of the current work is to analyze possible advantages of mounting Vortex Generators (VG's) on a wind turbine blade. Specifically, the project aims at investigating at which radial sections of the DTU 10 MW Reference Wind Turbine blade it is most beneficial to mount the VG's in order to increase the Annual Energy Production (AEP) under realistic conditions. The present analysis was carried out in several steps: (1) The clean two dimensional airfoil characteristics were first modified to emulate the effect of all possible combinations of VG's (1% high at suction side x/c=0.2-0.25) and two Leading Edge Roughness (LER) values along the whole blade span. (2) The combinations from Step 1, including the clean case were subsequently modified to take into account three dimensional effects. (3) BEM computations were carried out to determine the aerodynamic rotor performance using each of the datasets from Step 2 along the whole blade span for all wind speeds in the turbine control scheme. (4) Employing the assumption of radial independence between sections of the blades, and using the results of the BEM computations described in Step 3, it is possible to determine for each radial position independently whether it is beneficial to install VG's in the smooth and LER cases, respectively. The results indicated that surface roughness that corresponds to degradation of the power curve may to some extent be mitigated by installation of VG's. The present results also indicated that the optimal VG configuration in terms of maximizing AEP depends on the degree of severity of the LER. This is because, depending on the condition of blade surface, installation of VG's on an incorrect blade span or installation of VG's too far out on the blade may cause loss in AEP. The results also indicated that the worse condition of the blade surface, the more gain may be obtained from the installation of VG's.

Skrzypi?ski, Witold; Gaunaa, Mac; Bak, Christian

2014-06-01

259

Tree shoot bending generates hydraulic pressure pulses: a new long-distance signal?  

PubMed

When tree stems are mechanically stimulated, a rapid long-distance signal is induced that slows down primary growth. An investigation was carried out to determine whether the signal might be borne by a mechanically induced pressure pulse in the xylem. Coupling xylem flow meters and pressure sensors with a mechanical testing device, the hydraulic effects of mechanical deformation of tree stem and branches were measured. Organs of several tree species were studied, including gymnosperms and angiosperms with different wood densities and anatomies. Bending had a negligible effect on xylem conductivity, even when deformations were sustained or were larger than would be encountered in nature. It was found that bending caused transient variation in the hydraulic pressure within the xylem of branch segments. This local transient increase in pressure in the xylem was rapidly propagated along the vascular system in planta to the upper and lower regions of the stem. It was shown that this hydraulic pulse originates from the apoplast. Water that was mobilized in the hydraulic pulses came from the saturated porous material of the conduits and their walls, suggesting that the poroelastic behaviour of xylem might be a key factor. Although likely to be a generic mechanical response, quantitative differences in the hydraulic pulse were found in different species, possibly related to differences in xylem anatomy. Importantly the hydraulic pulse was proportional to the strained volume, similar to known thigmomorphogenetic responses. It is hypothesized that the hydraulic pulse may be the signal that rapidly transmits mechanobiological information to leaves, roots, and apices. PMID:24558073

Lopez, Rosana; Badel, Eric; Peraudeau, Sebastien; Leblanc-Fournier, Nathalie; Beaujard, François; Julien, Jean-Louis; Cochard, Hervé; Moulia, Bruno

2014-05-01

260

Mod-5A Wind Turbine Generator Program Design Report. Volume 2: Conceptual and Preliminary Design, Book 1  

NASA Technical Reports Server (NTRS)

The design, development and analysis of the 7.3 MW MOD-5A wind turbine generator is documented. There are four volumes. In Volume 2, book 1 the requirements and criteria for the design are presented. The conceptual design studies, which defined a baseline configuration and determined the weights, costs and sizes of each subsystem, are described. The development and optimization of the wind turbine generator are presented through the description of the ten intermediate configurations between the conceptual and final designs. Analyses of the system's load and dynamics are presented.

1984-01-01

261

Transient response to three-phase faults on a wind turbine generator. Ph.D. Thesis - Toledo Univ.  

NASA Technical Reports Server (NTRS)

In order to obtain a measure of its responses to short circuits a large horizontal axis wind turbine generator was modeled and its performance was simulated on a digital computer. Simulation of short circuit faults on the synchronous alternator of a wind turbine generator, without resort to the classical assumptions generally made for that analysis, indicates that maximum clearing times for the system tied to an infinite bus are longer than the typical clearing times for equivalent capacity conventional machines. Also, maximum clearing times are independent of tower shadow and wind shear. Variation of circuit conditions produce the modifications in the transient response predicted by analysis.

Gilbert, L. J.

1978-01-01

262

Novel sensorless generator control and grid fault ride-through strategies for variable-speed wind turbines and implementation on a new real-time simulation platform  

Microsoft Academic Search

The usage of MW-size variable-speed wind turbines as sources of energy has increased significantly during the last decade. Advantages over fixed-speed wind turbines include more efficient wind power extraction, reduced grid power fluctuation, and improved grid reactive power support. Two types of typical generation systems for large-size variable-speed wind turbines exist. One is the doubly-fed induction generator (DFIG) with a

Sheng Yang

2010-01-01

263

Operational behavior of a double-fed permanent magnet generator for wind turbines  

E-print Network

Greater efficiency in wind turbine systems is achieved by allowing the rotor to change its rate of rotation as the wind speed changes. The wind turbine system is decoupled from the utility grid and a variable speed operation ...

Reddy, Sivananda Kumjula

2005-01-01

264

Portable Hydraulic Powerpack  

NASA Technical Reports Server (NTRS)

Rechargeable hydraulic powerpack functions as lightweight, compact source of mechanical energy. Self-contained hydraulic powerpack derives energy from solid chemical charge. Combustion of charge initiated by small hammer, and revolving feeder replaces charges expended. Combustion gases cool during expansion in turbine and not too hot for release to atmosphere. Unit has applications driving wheelchairs and operating drills, winches, and other equipment in remote areas. Also replaces electric motors and internal-combustion engines as source of power in explosive atmospheres.

Anderson, L. A.; Henry, R. L.; Fedor, O. H.; Owens, L. J.

1986-01-01

265

3/5/2014 TinyMicro Wind Turbines Generate Electricity| New Energyand Fuel http://newenergyandfuel.com/http:/newenergyandfuel/com/2014/01/16/tiny-micro-wind-turbines-generate-electricity/ 1/12  

E-print Network

Off Topic Plans Politics Power Units Fuel Cells Hybrid Electric Piezoelectrics Solar Artificial-Power Quality, Free Shipping! #12;3/5/2014 TinyMicro Wind Turbines Generate Electricity| New Energyand Fuel http Photosynthesis Solar Panels Space Based Solar Thermal Solar Wind Power Storage Batteries Super Capacitors Thermal

Chiao, Jung-Chih

266

Evaluation of gas turbine and gasifier-based power generation system  

NASA Astrophysics Data System (ADS)

As a technology in early commercial phase, research work is needed to provide evaluation of the effects of alternative designs and technology advances and provide guidelines for development direction of Integrated Gasification Combined Cycle (IGCC) technology in future. The objective of this study is to evaluate the potential pay-offs as well as risks of technological infeasibility for IGCC systems and to provide insight regarding desired strategies for the future development of advanced IGCC systems. Texaco gasifier process is widely used in power generation. A process simulation model for a base Texaco gasifier-based IGCC system, including performance (e.g., efficiency), emissions, and cost, was implemented in the ASPEN Plus. The model is calibrated and verified based on other design studies. To find out the implications of the effects of coal compositions on IGCC plant, the Illinois No.6, Pittsburgh No.8, and West Kentucky coal are selected for comparison. The results indicate that the ash content and sulfur content of coal have effects on performance, SO2 emissions, and capital cost of IGCC system. As the main component for power generation, the effects of the most advanced Frame 7H and the current widely used Frame 7F gas turbine combined cycles on IGCC system were evaluated. The results demonstrated the IGCC system based on 7H gas turbine (IGCC-7H) has higher efficiency, lower CO2 emission, and lower cost of electricity than the 7FA based system (IGCC-7FA). A simplified spreadsheet model is developed for estimating mass and energy balance of gas turbine combined cycle. It demonstrated that an accurate and sensitive model can be implemented in a spreadsheet. This study implicated the ability to do desktop simulations to support policy analysis. Uncertainty analysis is implemented to find out the risks associated with the IGCC systems, i.e., there is about 80% probability that the uncertain results of the efficiency of IGCC-7FA system are lower than the deterministic result. The IGCC-7H system is superior to IGCC-7FA despite the uncertainty of inputs. Gasifier carbon conversion and project uncertainty are identified as the key uncertain inputs. The implications of the results provide guidelines for research direction and plant operation. Integration of air separation unit (ASU) and gas turbine has been used in some IGCC projects. The effects of different integration methods are evaluated. The results indicate that the integration method of nitrogen injection is preferred. The integrated IGCC design has higher efficiency and lower cost than nonintegrated design. Recommendations are provided based on the simulation and evaluation work, and main conclusions obtained in this study. The Frame 7H gas turbine is a promising technology to enable IGCC to be cost-competitive. Nitrogen injection is preferred for integration design. One or more standard IGCC systems should be developed to provide a consistent basis for benchmarking, verification, and comparison.

Zhu, Yunhua

267

Development of a High-Pressure/High-Temperature Downhole Turbine Generator  

SciTech Connect

The objective of this project as originally outlined has been to achieve a viable downhole direct current (DC) power source for extreme high pressure, high temperature (HPHT) environments of >25,000 psi and >250 C. The Phase I investigation posed and answered specific questions about the power requirements, mode of delivery and form factor the industry would like to see for downhole turbine generator tool for the HPHT environment, and noted specific components, materials and design features of that commercial system that will require upgrading to meet the HPHT project goals. During the course of Phase I investigation the scope of the project was HPHT downhole DC power. Phase I also investigated the viability of modifying a commercial expanded, without additional cost expected to the project, to include the addition of HT batteries to the power supply platform.

Timothy F. Price

2007-02-01

268

Development of the 7.3 MW MOD-5A wind-turbine generator system  

NASA Astrophysics Data System (ADS)

The General Electric Company Advanced Energy Programs Department is designing, under DOE/NASA sponsorship through Contract DEN 3-153, the MOD-5A wind-turbine system, which must generate electricity for less than 3.75 cents/kWh (1980 dollars). During the conceptual and preliminary design phases, the basic features were established as a result of tradeoff and optimization studies driven by minimizing the system cost of energy. During the past year, the program has been in the final design phase, and a reassessment to minimize risk has received strong emphasis in the design process. The program has progressed to the point that an agreement of sale has been reached for the first unit.

Barton, R. S.; Lucas, W. C.

1983-12-01

269

Development and testing of the Kaman 40 kW turbine generator  

NASA Astrophysics Data System (ADS)

A horizontal axis wind turbine generator rated at 40 kW at 9 m/s is discussed. The system has a 19.5 m diameter rotor with two fiberglass blades mounted downwind of the tower at a hub height of 23 m. To accommodate various output configurations, a variable pitch rotor with a microprocessor controller is incorporated. During fabrication, lessons were learned which will improve producibility at lower costs, and these are discussed. Also discussed are some of the development problems encountered and corrected during the Contractor's test program and during the testing now in process at the Rocky Flats facility. Performance appears to show good correlation with predicted levels, and the prototype is considered to represent a successful system on which to base future production.

Goodale, B. A.

270

Experience and assessment of the DOE-NASA Mod-1 2000-Kilowatt wind turbine generator at Boone, North Carolina  

NASA Technical Reports Server (NTRS)

The Mod 1 program objectives are defined. The Mod 1 wind turbine is described. In addition to the steel blade operated on the wind turbine, a composite blade was designed and manufactured. During the early phase of the manufacturing cycle of Mod 1A configuration was designed that identified concepts such as partial span control, a soft tower, and upwind teetered rotors that were incorporated in second and third generation industry designs. The Mod 1 electrical system performed as designed, with voltage flicker characteristics within acceptable utility limits. Power output versus wind speed equaled or exceeded design predictions. The wind turbine control system was operated successfully at the site and remotely from the utility dispatcher's office. During wind turbine operations, television interference was experienced by the local residents. As a consequence, operations were restricted. Although not implemented, two potential solutions were identified. In addition to television interference, a few local residents complained bout objectionable sound, particularly the 'thump' as the blade passed behind the tower. To eliminate objections, the sound generation level was reduced by 10 dB by reducing the rotor speed from 35 rpm to 23 rpm. Bolts in the drive train fractured. A solution was identified but not implemented. The public reaction toward the Mod 1 wind turbine program was overwhelmingly favorable.

Collins, J. L.; Shaltenc, R. K.; Poor, R. H.; Barton, R. S.

1982-01-01

271

Low NO{sub x} turbine power generation utilizing low Btu GOB gas. Final report, June--August 1995  

SciTech Connect

Methane, a potent greenhouse gas, is second only to carbon dioxide as a contributor to potential global warming. Methane liberated by coal mines represents one of the most promising under exploited areas for profitably reducing these methane emissions. Furthermore, there is a need for apparatus and processes that reduce the nitrogen oxide (NO{sub x}) emissions from gas turbines in power generation. Consequently, this project aims to demonstrate a technology which utilizes low grade fuel (CMM) in a combustion air stream to reduce NO{sub x} emissions in the operation of a gas turbine. This technology is superior to other existing technologies because it can directly use the varying methane content gases from various streams of the mining operation. The simplicity of the process makes it useful for both new gas turbines and retrofitting existing gas turbines. This report evaluates the feasibility of using gob gas from the 11,000 acre abandoned Gateway Mine near Waynesburg, Pennsylvania as a fuel source for power generation applying low NO{sub x} gas turbine technology at a site which is currently capable of producing low grade GOB gas ({approx_equal} 600 BTU) from abandoned GOB areas.

Ortiz, I.; Anthony, R.V.; Gabrielson, J.; Glickert, R.

1995-08-01

272

Determining wind turbine capacity for expansion of off grid Internal Combustion Generators (ICG) system; why it bec o mes challenging?  

Microsoft Academic Search

Combining renewable energy sources to Internal Combustion Generator (ICG) systems for standalone applications is becoming popular due to higher depletion rate of fossil fuel resources and global concerns on Green House Gas (GHG) emission. In this study, Hybrid Energy System (HES) modeling and simulation was done in order to investigate the impact of Wind Turbine Capacity (WTC) for expansion of

A. T. D. Perera; D. M. I. J. Wickremasinghe; D. V. S. Mahindarathna; R. A. Attalage; K. K. C. K. Perera; E. M. Bartholameuz

2010-01-01

273

MOD-5A wind turbine generator program design report: Volume 1: Executive Summary  

NASA Technical Reports Server (NTRS)

The design, development and analysis of the 7.3 MW MOD-5A wind turbine generator covering work performed between July 1980 and June 1984 is discussed. The report is divided into four volumes: Volume 1 summarizes the entire MOD-5A program, Volume 2 discusses the conceptual and preliminary design phases, Volume 3 describes the final design of the MOD-5A, and Volume 4 contains the drawings and specifications developed for the final design. Volume 1, the Executive Summary, summarizes all phases of the MOD-5A program. The performance and cost of energy generated by the MOD-5A are presented. Each subsystem - the rotor, drivetrain, nacelle, tower and foundation, power generation, and control and instrumentation subsystems - is described briefly. The early phases of the MOD-5A program, during which the design was analyzed and optimized, and new technologies and materials were developed, are discussed. Manufacturing, quality assurance, and safety plans are presented. The volume concludes with an index of volumes 2 and 3.

1984-01-01

274

MOD-5A wind turbine generator program design report: Volume 1: Executive Summary  

NASA Astrophysics Data System (ADS)

The design, development and analysis of the 7.3 MW MOD-5A wind turbine generator covering work performed between July 1980 and June 1984 is discussed. The report is divided into four volumes: Volume 1 summarizes the entire MOD-5A program, Volume 2 discusses the conceptual and preliminary design phases, Volume 3 describes the final design of the MOD-5A, and Volume 4 contains the drawings and specifications developed for the final design. Volume 1, the Executive Summary, summarizes all phases of the MOD-5A program. The performance and cost of energy generated by the MOD-5A are presented. Each subsystem - the rotor, drivetrain, nacelle, tower and foundation, power generation, and control and instrumentation subsystems - is described briefly. The early phases of the MOD-5A program, during which the design was analyzed and optimized, and new technologies and materials were developed, are discussed. Manufacturing, quality assurance, and safety plans are presented. The volume concludes with an index of volumes 2 and 3.

1984-08-01

275

GETRAN: A generic, modularly structured computer code for simulation of dynamic behavior of aero- and power generation gas turbine engines  

NASA Astrophysics Data System (ADS)

The design concept, the theoretical background essential for the development of the modularly structured simulation code GETRAN, and several critical simulation cases are presented in this paper. The code being developed under contract with NASA Lewis Research Center is capable of simulating the nonlinear dynamic behavior of single- and multispool core engines, turbofan engines, and power generation gas turbine engines under adverse dynamic operating conditions. The modules implemented into GETRAN correspond to components of existing and new-generation aero- and stationary gas turbine engines with arbitrary configuration and arrangement. For precise simulation of turbine and compressor components, row-by-row diabatic and adiabatic calculation procedures are implemented that account for the specific turbine and compressor cascade, blade geometry, and characteristics. The nonlinear, dynamic behavior of the subject engine is calculated solving a number of systems of partial differential equations, which describe the unsteady behavior of each component individually. To identify each differential equation system unambiguously, special attention is paid to the addressing of each component. The code is capable of executing the simulation procedure at four levels, which increase with the degree of complexity of the system and dynamic event. As representative simulations, four different transient cases with single- and multispool thrust and power generation engines were simulated. These transient cases vary from throttling the exit nozzle area, operation with fuel schedule, rotor speed control, to rotating stall and surge.

Schobeiri, M. T.; Attia, M.; Lippke, C.

1994-07-01

276

Effect of front guide nozzle shape on the flow characteristics in an augmentation channel of a direct drive turbine for wave power generation  

Microsoft Academic Search

There is an increasing interest in cross flow turbines (also known as Banki turbines) for small and low head applications\\u000a because of their simple structure as well as low capital and maintenance costs. The present work aims at implementing the\\u000a direct drive turbine (DDT) of cross flow type for wave power generation. A numerical wave tank was used to simulate

Deepak Prasad; Mohammed Asid Zullah; Mohammed Rafiuddin Ahmed; Young-Ho Lee

2010-01-01

277

Macroscopic cross section generation and application for coupled spatial kinetics and thermal hydraulics analysis with SAS-DIF3DK  

SciTech Connect

This paper discusses the importance of modeling the transient behavior of multigroup cross sections in the context of coupled reactor physics and thermal-hydraulic computations with the SAS-DIF3DK computer code. The MACOEF macroscopic cross section methodology is presented. Results from benchmark verification calculations with a continuous-energy Monte Carlo are reported. Analysis of the Chernobyl accident is made using correlated WIMS-D4M generated group constants with special emphasis placed on the impact of modeling assumptions on the progression of the accident simulation.

Turski, R.B.; Morris, E.E.; Taiwo, T.A.; Cahalan, J.E.

1997-08-01

278

A Review of Current Issues in Lightning Protection of New-Generation Wind-Turbine Blades  

Microsoft Academic Search

The salient issues related to lightning protection of long wind-turbine blades are discussed in this paper. We show that the lightning protection of modern wind turbines presents a number of new challenges due to the geometrical, electrical, and mechanical particularities of the turbines. The risk assessment for the lightning-protection-system design is solely based today on downward flashes. We show in

Farhad Rachidi; Marcos Rubinstein; Joan Montanya; JosÉ-Luis Bermudez; RubÉn Rodriguez Sola; GlÒria Sola; Nikolay Korovkin

2008-01-01

279

Mod-5A wind turbine generator program design report. Volume 3: Final design and system description, book 2  

NASA Technical Reports Server (NTRS)

The design, development and analysis of the 7.3MW MOD-5A wind turbine generator is documented. The report is divided into four volumes: Volume 1 summarizes the entire MOD-5A program, Volume 2 discusses the conceptual and preliminary design phases, Volume 3 describes the final design of the MOD-5A, and Volume 4 contains the drawings and specifications developed for the final design. Volume 3, book 2 describes the performance and characteristics of the MOD-5A wind turbine generator in its final configuration. The subsystem for power generation, control, and instrumentation subsystems is described in detail. The manufacturing and construction plans, and the preparation of a potential site on Oahu, Hawaii, are documented. The quality assurance and safety plan, and analyses of failure modes and effects, and reliability, availability and maintainability are presented.

1984-01-01

280

Electrical power obtained from burning landfill gas into a gas turbine generator: Experience after one year of operation  

SciTech Connect

A typical example of a ``waste to energy'' concept can be found also in the landfill environment. The biogas derived by fermentation process is usually burnt into gas engines. This choice is usually due to the electric efficiency that is normally higher than gas turbine application and to the size that usually, almost in Italian landfill size, does not allow power higher than 1,000 kW. On the other side gas turbine applications, typically based on generator sets greater than 1,000 kW do not require special biogas pre-treatment; require less maintenance and have an extremely higher reliability. The paper describes an application of a gas turbine generator of 4,800 kW outlining the experiences collected after one year of operation. During this period, the system fulfilled the target of a total operating time greater than 8,000 hours. Description is done of the biogas compression system feeding the turbine and also of the subsystem adopted to reach the above mentioned target reliability.

Fabbri, R.; Mignani, N.

1998-07-01

281

Very Low Head Turbine Deployment in Canada  

NASA Astrophysics Data System (ADS)

The Very Low Head (VLH) turbine is a recent turbine technology developed in Europe for low head sites in the 1.4 - 4.2 m range. The VLH turbine is primarily targeted for installation at existing hydraulic structures to provide a low impact, low cost, yet highly efficient solution. Over 35 VLH turbines have been successfully installed in Europe and the first VLH deployment for North America is underway at Wasdell Falls in Ontario, Canada. Deployment opportunities abound in Canada with an estimated 80,000 existing structures within North America for possible low-head hydro development. There are several new considerations and challenges for the deployment of the VLH turbine technology in Canada in adapting to the hydraulic, environmental, electrical and social requirements. Several studies were completed to determine suitable approaches and design modifications to mitigate risk and confirm turbine performance. Diverse types of existing weirs and spillways pose certain hydraulic design challenges. Physical and numerical modelling of the VLH deployment alternatives provided for performance optimization. For this application, studies characterizing the influence of upstream obstacles using water tunnel model testing as well as full-scale prototype flow dynamics testing were completed. A Cold Climate Adaptation Package (CCA) was developed to allow year-round turbine operation in ice covered rivers. The CCA package facilitates turbine extraction and accommodates ice forces, frazil ice, ad-freezing and cold temperatures that are not present at the European sites. The Permanent Magnet Generator (PMG) presents some unique challenges in meeting Canadian utility interconnection requirements. Specific attention to the frequency driver control and protection requirements resulted in a driver design with greater over-voltage capability for the PMG as well as other key attributes. Environmental studies in Europe included fish friendliness testing comprised of multiple in-river live passage tests for a wide variety of fish species. Latest test results indicate fish passage survivability close to 100%. Further fish studies are planned in Canada later this year. Successful deployment must meet societal requirements to gain community acceptance and public approval. Aesthetics considerations include low noise, disguised control buildings and vigilant turbine integration into the low profile existing structures. The resulting design was selected for deployment at existing historic National Park waterway structures. The integration of all of these design elements permits the successful deployment of the VLH turbine in Canada.

Kemp, P.; Williams, C.; Sasseville, Remi; Anderson, N.

2014-12-01

282

A Fault-Tolerant Multiphase Permanent Magnet Generator for Marine Current Turbine Applications  

E-print Network

challenge for marine current energy development is to minimize the operation costs and maintenance on offshore wind turbine systems. Marine current turbines are characterized by a very difficult access for renewable energy developers is obvious. Seawater is more than 800 times denser than air. So, typical marine

Boyer, Edmond

283

Conceptual design of a fixed-pitch wind turbine generator system rated at 400 kilowatts  

NASA Technical Reports Server (NTRS)

The design and cost aspects of a fixed pitch, 400 kW Wind Turbine Generator (WTG) concept are presented. Improvements in reliability and cost reductions were achieved with fixed pitch operation and by incorporating recent advances in WTG technology. The specifications for this WTG concept were as follows: (1) A fixed pitch, continuous wooden rotor was to be provided by the Gougeon Bros. Co. (2) An 8 leg hyperboloid tower that showed promise as a low cost structure was to be used. (3) Only commercially available components and parts that could be easily fabricated were to be considered. (4) Design features deemed desirable based on recent NASA research efforts were to be incorporated. Detailed costs and weight estimates were prepared for the second machine and a wind farm of 12 WTG's. The calculated cost of energy for the fixed pitch, twelve unit windfarm is 11.5 cents/kW hr not including the cost of land and access roads. The study shows feasibility of fixed pitch, intermediate power WTG operation.

Pintz, A.; Kasuba, R.; Spring, J.

1984-01-01

284

Conceptual design of the 6 MW Mod-5A wind turbine generator  

NASA Astrophysics Data System (ADS)

The General Electric Company, Advanced Energy Programs Department, is designing under DOE/NASA sponsorship the MOD-5A wind turbine system which must generate electricity for 3.75 cent/KWH (1980) or less. During the Conceptual Design Phase, completed in March, 1981, the MOD-5A WTG system size and features were established as a result of tradeoff and optimization studies driven by minimizing the system cost of energy (COE). This led to a 400' rotor diameter size. The MOD-5A system which resulted is defined in this paper along with the operational and environmental factors that drive various portions of the design. Development of weight and cost estimating relationships (WCER's) and their use in optimizing the MOD-5A are discussed. The results of major tradeoff studies are also presented. Subsystem COE contributions for the 100th unit are shown along with the method of computation. Detailed descriptions of the major subsystems are given, in order that the results of the various trade and optimization studies can be more readily visualized.

Barton, R. S.; Lucas, W. C.

285

PIV and Hotwire Measurement and Analysis of Tip Vortices and Turbulent Wake Generated by a Model Horizontal Axis Wind Turbine  

NASA Astrophysics Data System (ADS)

Understanding vortical flow structures and turbulence in the wake flow behind a Horizontal Axis Wind Turbine (HAWT) has widespread applications in efficient blade design. Moreover, the knowledge of wake-turbine interactions allows us to devise optimal operational parameters, such as the spatial allocation and control algorithms of wind turbines, for a densely populated wind farm. To understand the influence of tip vortices on energy containing mean flow and turbulence, characteristics of vortical structures and turbulence must be quantified thoroughly. In this study, we conduct phase-locked Particle Image Velocimetry (PIV) measurements of the flow before and after a model HAWT, which is located in a zero-pressure gradient wind tunnel with a cross section of 1.7 × 1.7 m and a test section of 16 m in length. A three-blade model HAWT with a diameter of 605 mm and tip-speed ratio of 5 is used. PIV images are recorded by a 2048 × 2048 CCD camera and streamed at 6 Hz continuously; and phased locked with the passage of the blade at its vertical position. Each PIV measurement covers a 0.13 × 0.13 m2 sample area with the spatial resolution of 63 ?m and a vector spacing of 0.5 mm. All experiments are conducted at the free-stream wind speed of 10 m/s. Flow fields at thirty consecutive downstream locations up to six rotor diameters and 144 mid chord lengths are measured. At each location, we obtain at least 10,000 instantaneous PIV realizations or 20,000 images. Three different configurations: single, dual, and trio turbines located at 5 rotor diameter upstream to each other, are examined experimentally. The flow statistics include mean wake velocity distributions, characteristics of tip vortices evolving downstream, fluctuation velocity, turbulent kinetic energy, stresses, and energy spectra. We find that tip vortices decay much faster in the wake of the upstream turbines (multiple-turbine configurations), whereas they maintain the coherence and strength behind a single turbine. The tip vortices entrain the high speed free-stream fluids and subsequently replenish the loss of momentum into the wake. Such a mechanism is greatly mitigated in the multiple-turbine scenarios. On-going analysis is to elucidate the generation, evolution and dissipation of the tip vortices in the various configurations.

Green, D.; Tan, Y. M.; Chamorro, L. P.; Arndt, R.; Sotiropoulos, F.; Sheng, J.

2011-12-01

286

Gas turbine control  

Microsoft Academic Search

A description is given of a control system for a gas turbine engine having a compressor-combustor-turbine gas generator, a power turbine energized by the gas generator having a variable nozzle, a servomechanism for varying the nozzle, and a settable engine power level control. The system includes input controls responsive to engine inlet air temperature, the power level control setting, gas

J. L. Davis; E. L. Lopke; L. J. Pechous

1974-01-01

287

Detailed design of a 30kW switched reluctance starter\\/generator system for a gas turbine engine application  

Microsoft Academic Search

A new switched reluctance starter\\/generator (SR S\\/G) system has been developed for an aircraft engine application. The system is rated at 30 kW, 270 Vdc, 52 k r\\/min maximum operating speed. The system also provides 17 hp to start the 1400-hp engine. The system consists of an SR machine directly coupled to the gas turbine engine, an inverter converter unit

Caio A. Ferreira; Stephen R. Jones; William S. Heglund; William D. Jones

1995-01-01

288

A New Non-gaussian Turbulent Wind Field Generator to Estimate Design-Loads of Wind-Turbines  

Microsoft Academic Search

Climate change and finite fossil fuel resources make it urgent to turn into electricity generation from mostly renewable energies.\\u000a One major part will play wind-energy supplied by wind-turbines of rated power up to 10 MW. For their design and development\\u000a wind field models have to be used. The standard models are based on the empirical spectra, for example by von

A. P. Schaffarczyk; H. Gontier; D. Kleinhans; R. Friedrich

2009-01-01

289

National Renewable Energy Laboratory program on lightning risk and wind turbine generator protection  

SciTech Connect

This paper will describe the NREL program for addressing lightning protection for wind turbines. A test program will begin this summer at the Central and South West Services Inc. (CSW) wind farm near Fort Davis, Texas, to assess lightning risk, the frequency of lightning strikes on wind turbines compared to risk assessment predictions, and the effectiveness of some protection techniques. A Web page will be assembled to provide resources for designers and operators and feedback for issues as they arise. Also, a database of lightning events (and corresponding damage) will be collected to assist in maturing the understanding of wind turbine lightning protection.

Muljadi, E. [National Renewable Energy Lab., Golden, CO (United States)] [National Renewable Energy Lab., Golden, CO (United States); McNiff, B. [McNiff Light Industry, Blue Hill, ME (United States)] [McNiff Light Industry, Blue Hill, ME (United States)

1997-09-01

290

Accelerated hydrolysis of organophosphorus hydraulic fluids and related organophosphates using sodium-perborate generated HO{sub 2}{sup -}  

SciTech Connect

Methods of remediation of contaminated soil and groundwater at military bases becomes more important as more military installations are closing and the public demands environmental restoration. Chemical degradation of the contaminants is preferable to other clean-up methods which simply remove or entomb the contamination without reducing its toxicity. One relatively ubiquitous source of soil contamination at military sites where high-performance aircraft have been operated is phosphate-ester hydraulic fluids, which were often rinsed from the aircraft into drainage ditches during routine maintenance. The chemical degradation of isomers of TCP (tricresylphosphate), a major component of flame-retardant hydraulic fluids, and other OPs (organophosphates) was investigated. A method using sodium perborate-generated HO{sub 2}{sup -} as the hydrolyzing nucleophile was modified for sparingly water soluble OPs such as TCP. Rates of hydrolysis in sodium perborate solutions were 10 to 100 times faster than hydrolysis in sodium carbonate control solutions with similar pH levels. Degradation rates among the OPs tested varied due to differences in their leaving groups, steric hindrance of nucleophilic attack, and between thio and oxy esters. Application of this hydrolysis method in a soil-slurry is currently under investigation.

David, M.D.; Seiber, J.N. [Univ. of Nevada, Reno, NV (United States)

1995-12-01

291

Physical modeling of wind turbine generators in a small scale analog system  

E-print Network

This project represents the physical modeling and experimental test of a Doubly-fed Induction Machine (DFIM), in order to substantially analyze the characteristic behaviors of wind turbines and its use in the micro-grid ...

Wang, Xuntuo

2014-01-01

292

Large wind turbines: A utility option for the generation of electricity  

NASA Technical Reports Server (NTRS)

The economic and technical potential of wind energy in the United States is discussed. Particular attention is given to the status of wind turbine operational experience as well as the environmental posture of the technology.

Robbins, W. H.; Thomas, R. L.; Baldwin, D. H.

1980-01-01

293

A medium frequency transformer with multiple secondary windings for medium voltage converter based wind turbine power generating systems  

NASA Astrophysics Data System (ADS)

Recent advances in magnetic materials have led to the development of compact and light weight, medium and high frequency transformers, which would be a possible solution to reducing the size and weight of wind turbine power generating systems. This paper presents the overall design and analysis of a Metglas amorphous alloy 2605SA1 based medium frequency transformer to generate the isolated balanced multiple DC supplies for medium voltage converter systems. A comprehensive electromagnetic analysis is conducted on the proposed design based on experimental results. The test stand, data analysis, and test results are discussed.

Islam, Md Rabiul; Guo, Youguang; Zhu, Jianguo

2013-05-01

294

NREL Controllable Grid Interface for Testing MW-Scale Wind Turbine Generators (Poster)  

SciTech Connect

In order to understand the behavior of wind turbines experiencing grid disturbances, it is necessary to perform a series of tests and accurate transient simulation studies. The latest edition of the IEC 61400-21 standard describes methods for such tests that include low voltage ride-through (LVRT), active power set-point control, ramp rate limitations, and reactive power capability tests. The IEC methods are being widely adopted on both national and international levels by wind turbine manufacturers, certification authorities, and utilities. On-site testing of wind turbines might be expensive and time consuming since it requires both test equipment transportation and personnel presence in sometimes remote locations for significant periods of time because such tests need to be conducted at certain wind speed and grid conditions. Changes in turbine control software or design modifications may require redoing of all tests. Significant cost and test-time reduction can be achieved if these tests are conducted in controlled laboratory environments that replicate grid disturbances and simulation of wind turbine interactions with power systems. Such testing capability does not exist in the United States today. An initiative by NREL to design and construct a 7-MVA grid simulator to operate with the existing 2.5 MW and new upcoming 5-MW dynamometer facilities will fulfill this role and bring many potential benefits to the U.S. wind industry with the ultimate goal of reducing wind energy integration costs.

McDade, M.; Gevorgian, V.; Wallen, R.; Erdman, W.

2013-04-01

295

Abstract--A bi-objective optimization model of power and power changes generated by a wind turbine is discussed in this  

E-print Network

1 Abstract--A bi-objective optimization model of power and power changes generated by a wind theory is introduced. Data-mining algorithms were used to identify the model of power generation from prediction, power ramp rate, data mining, wind turbine operation strategy, generator torque, blade pitch

Kusiak, Andrew

296

Measurement of aeroacoustic noise generated on wind turbine blades modified by trailing edge brushes  

NASA Astrophysics Data System (ADS)

As wind technology becomes a larger portion of the energy production picture, the problematic interactions between the machines and society will continue to become more pronounced. Of these problems, wind turbine noise is one of the most important to the future of wind turbine development. This study looks at the effect trailing edge brushes mounted on the 2 bladed Controls Advance Research Turbine (CART 2), located at the National Wind Technology Center, have on the overall acoustic and aerodynamic performance of the blades. The use of trailing edge brushes reduced the aeroacoustic noise by 1.0 to 5.0 dB over the baseline blade, depending on wind speed. This acoustic performance comes at a cost to the aerodynamic performance of the blades. The aerodynamic performance indicators, such as turbine power and root bending moments show that increased drag due to the brushes is the main contributor to the reduction in power production. An economic analysis also investigated how to best use noise mitigation devices to optimize acoustic, power performance and loads of a 600 kW baseline turbine, such as the CART 2. The analysis shows that the use of up a noise mitigation device of 4 dB is best used by increasing the rotor diameter and the power rating of the machine, from a 43.3 m diameter, 600 kW machine to a 68.8 m diameter, 886.7 kW machine. This increase resulted in an annual energy production increase of 414% when using a Rayleigh wind distribution with at a mean annual wind speed of 8.5 m/s. This is a reduction of cost of energy from 0.0463 per kWh to 0.0422 kWh. This reduction in energy production costs helps to explain the continuing trend of turbine machine growth in both rotor diameter and power rating.

Asheim, Michael J.

297

Control system design for the MOD-5A 7.3 mW wind turbine generator  

NASA Technical Reports Server (NTRS)

This paper provides descriptions of the requirements analysis, hardware development and software development phases of the Control System design for the MOD-5A 7.3 mW Wind Turbine Generator. The system, designed by General Electric Company, Advanced Energy Programs Department, under contract DEN 3-153 with NASA Lewis Research Center and DOE, provides real time regulation of rotor speed by control of both generator torque and rotor torque. A variable speed generator system is used to provide both airgap torque control and reactive power control. The wind rotor is designed with segmented ailerons which are positioned to control blade torque. The central component of the control system, selected early in the design process, is a programmable controller used for sequencing, alarm monitoring, communication, and real time control. Development of requirements for use of aileron controlled blades and a variable speed generator required an analytical simulation that combined drivetrain, tower and blade elastic modes with wind disturbances and control behavior. An orderly two phase plan was used for controller software development. A microcomputer based turbine simulator was used to facilitate hardware and software integration and test.

Barton, Robert S.; Hosp, Theodore J.; Schanzenbach, George P.

1995-01-01

298

Using the Biphase Turbine to Generate Useful Energy from Process Streams  

E-print Network

The Biphase turbine is a device for effectively converting enthalpy changes in a two-phase (liquid and gas) working fluid into mechanical energy. No other device is currently available for performing this task. The working fluid may be a single...

Helgeson, N. L.; Studhalter, W. R.

1981-01-01

299

Hybrid Electro-Mechanical Simulation Tool for Wind Turbine Generators: Preprint  

SciTech Connect

This paper describes the use of MATLAB/Simulink to simulate the electrical and grid-related aspects of a WTG and the FAST aero-elastic wind turbine code to simulate the aerodynamic and mechanical aspects of the WTG. The combination of the two enables studies involving both electrical and mechanical aspects of the WTG.

Singh, M.; Muljadi, E.; Jonkman, J.

2013-05-01

300

Automatic generation control of a wind farm with variable speed wind turbines  

Microsoft Academic Search

Wind farms are considered to be negative loads from the point of view of a utility manager. Modern variable-speed wind turbines offer the possibility for controlling active and reactive power separately. This paper presents a new integrated control system of a wind farm according to the utility manager's requirements. This control system is based on two control levels: a supervisory

José Luis Rodríguez-Amenedo; Santiago Arnalte; Juan Carlos Burgos

2002-01-01

301

Modelling of the Turbulent Wall Jet Generated by a Pitched Blade Turbine Impeller  

Microsoft Academic Search

CFD modelling results have been presented for a flat-bottomed tank with a pitched blade turbine impeller and four baffles. Four turbulence models, i.e. the standard k- ?, the RNG k-?, the realizable k-? and the Reynolds stress model have been used in the modelling. The simulated values of the tangential and axial mean velocity components along with the kinetic energy

Zdzislaw Jaworski; Barbara Zakrzewska

2002-01-01

302

Fiberglass composite blades for the 2 MW Mod1 wind turbine generator  

Microsoft Academic Search

In mid-1979, NASA contracted with Kaman Aerospace Corporation for the design, manufacture, and ground testing of two 100 foot composite rotor blades intended for operation on the Mod-1 wind turbine. The Mod-1 blades have been completed and are currently stored at the Kaman facility. The design, tooling, fabrication, and testing phases which have been carried out to date, as well

W. R. Batesole

1982-01-01

303

MOD-OA 200 kW wind turbine generator engineering  

NASA Astrophysics Data System (ADS)

Engineering drawings and the detailed mechanical and electrical design of a horizontal-axis wind turbine designed for DOE at the NASA Lewis Research Center and installed in Clayton, New Mexico are discussed. The drawings show the hub, pitch change mechanism, drive train, nacelle equipment, yaw drive system, tower, foundation, electrical power systems, and the control and safety systems.

Andersen, T. S.; Bodenschatz, C. A.; Eggers, A. G.; Hughes, P. S.; Lampe, R. F.

1980-08-01

304

MOD-OA 200 kW wind turbine generator engineeringing  

NASA Technical Reports Server (NTRS)

Engineering drawings and the detailed mechanical and electrical design of a horizontal-axis wind turbine designed for DOE at the NASA Lewis Research Center and installed in Clayton, New Mexico are discussed. The drawings show the hub, pitch change mechanism, drive train, nacelle equipment, yaw drive system, tower, foundation, electrical power systems, and the control and safety systems.

Andersen, T. S.; Bodenschatz, C. A.; Eggers, A. G.; Hughes, P. S.; Lampe, R. F.

1980-01-01

305

Dynamic characteristics of a pump-turbine during hydraulic transients of a model pumped-storage system: 3D CFD simulation  

NASA Astrophysics Data System (ADS)

The runaway process in a model pumped-storage system was simulated for analyzing the dynamic characteristics of a pump-turbine. The simulation was adopted by coupling 1D (One Dimensional) pipeline MOC (Method of Characteristics) equations with a 3D (Three Dimensional) pump-turbine CFD (Computational Fluid Dynamics) model, in which the water hammer wave in the 3D zone was defined by giving a pressure dependent density. We found from the results that the dynamic performances of the pump-turbine do not coincide with the static operating points, especially in the S-shaped characteristics region, where the dynamic trajectories follow ring-shaped curves. Specifically, the transient operating points with the same Q11 and M11 in different moving directions of the dynamic trajectories give different n11. The main reason of this phenomenon is that the transient flow patterns inside the pump-turbine are influenced by the ones in the previous time step, which leads to different flow patterns between the points with the same Q11 and M11 in different moving directions of the dynamic trajectories.

Zhang, X. X.; Cheng, Y. G.; Xia, L. S.; Yang, J. D.

2014-12-01

306

Interaction of turbine-generated turbulence with agricultural crops: Conceptual framework and preliminary results  

NASA Astrophysics Data System (ADS)

The US Midwest is a unique location for wind power production because wind farms in this region, unlike any other, are co-located within major agricultural production systems that are among the most highly productive in the world. Iowa has over 3,000 MW of installed power in wind farms typically consisting of 75-120 turbines positioned within agricultural fields with irregular spacing but inter-turbine distances in some cases less than 300 m. Wind turbines extract energy from the ambient flow and change mean and turbulent characteristics of wind flow over and within the crop canopy. Turbulent exchange of air from within the crop canopy regulates vertical fluxes of heat, moisture, momentum, and CO2. Changes in wind speed and turbulence structure by wind farms and isolated wind turbines will influence crop growth, productivity, and seed quality in unknown ways. For instance, enhanced vertical fluxes of heat and moisture may help cool the crop on hot summer days (beneficial) but may enhance loss of soil moisture (detrimental). Faster drying of dew from the crop in the morning reduces leaf wetness, which is a condition favoring growth of fungus, mold and toxins. Corn and soybeans typically draw down ambient CO2 levels by 15-20% during the day in the peak growing season, providing an opportunity to enhance downward fluxes of CO2 into the crop canopy by turbine-induced turbulence. Reduction of high winds and resulting leaf shredding and stalk lodging are documented positive effects of agricultural shelterbelts and may be benefits of turbines as well. Enhanced surface evaporation during fall dry-down would improve seed readiness for storage and reduce artificial drying costs. Modification of surface wind convergence/divergence patterns may enhance convection and change rainfall patterns and modify snow deposition, melting, and soil-moisture-recharge in winter. Wind machines are widely used in orchards and vineyards for avoiding killing freezes, but turbine benefits for such purposes for growing commodity agricultural crops are unknown. Suppressing effects of a premature freeze could extend the growing season by two or more weeks. Aerodynamic surface roughness influences the mean wind at hub height of wind turbines. Type of crop (e.g., corn vs. soybeans) and stage of growth will influence roughness, as will management practices (smooth surface vs. crop residue and tillage-induced roughness). Management of crop residue and snow cover influences surface albedo and hence diabatic influences on turbulent loss of momentum at the surface. We have launched a pilot project to assess the interaction of turbines with crops in Iowa by use of models and measurements. Preliminary studies show that turbulence kinetic energy in the lee of turbines may be enhanced by as much as 300% near hub height and 40% at 10 m above the ground under neutral flow conditions. Field observations of fluxes of CO2, heat, and water vapor have been made outside of wind farms, and plans call for simultaneous measurements to be made within and outside of wind farms.

Takle, E. S.; Rajewski, D. A.; Segal, M.; Elmore, R.; Hatfield, J.; Prueger, J. H.; Taylor, S. E.

2009-12-01

307

A Pitch Control Malfunction Analysis for Wind Turbines with Permanent Magnet Synchronous Generator and Full-power Converters: Proportional Integral Versus Fractional-order Controllers  

Microsoft Academic Search

A transient analysis for two full-power converter wind turbines equipped with a permanent magnet synchronous generator is studied in this article, taking into consideration, as a new contribution to earlier studies, a pitch control malfunction. The two full-power converters considered are, respectively, a two-level and a multi-level converter. Moreover, a novel control strategy based on fractional-order controllers for wind turbines

R. Melício; V. M. F. Mendes; J. P. S. Catalão

2010-01-01

308

Evolutionary algorithm based optimization of hydraulic machines utilizing a state-of-the-art block coupled CFD solver and parametric geometry and mesh generation tools  

NASA Astrophysics Data System (ADS)

An efficient hydraulic optimization procedure, suitable for industrial use, requires an advanced optimization tool (EASY software), a fast solver (block coupled CFD) and a flexible geometry generation tool. EASY optimization software is a PCA-driven metamodel-assisted Evolutionary Algorithm (MAEA (PCA)) that can be used in both single- (SOO) and multiobjective optimization (MOO) problems. In MAEAs, low cost surrogate evaluation models are used to screen out non-promising individuals during the evolution and exclude them from the expensive, problem specific evaluation, here the solution of Navier-Stokes equations. For additional reduction of the optimization CPU cost, the PCA technique is used to identify dependences among the design variables and to exploit them in order to efficiently drive the application of the evolution operators. To further enhance the hydraulic optimization procedure, a very robust and fast Navier-Stokes solver has been developed. This incompressible CFD solver employs a pressure-based block-coupled approach, solving the governing equations simultaneously. This method, apart from being robust and fast, also provides a big gain in terms of computational cost. In order to optimize the geometry of hydraulic machines, an automatic geometry and mesh generation tool is necessary. The geometry generation tool used in this work is entirely based on b-spline curves and surfaces. In what follows, the components of the tool chain are outlined in some detail and the optimization results of hydraulic machine components are shown in order to demonstrate the performance of the presented optimization procedure.

S, Kyriacou; E, Kontoleontos; S, Weissenberger; L, Mangani; E, Casartelli; I, Skouteropoulou; M, Gattringer; A, Gehrer; M, Buchmayr

2014-12-01

309

Preliminary analysis of the audible noise of constant-speed, horizontal-axis wind-turbine generators  

SciTech Connect

An analytical procedure has been developed for calculating certain aerodynamic sound levels produced by large, horizontal-axis wind-turbine generators (WTG's) such as the DOE/NASA Mods-0, -0A, -1, and -2. This preliminary procedure is based upon very limited field data from the Mod-0. It postulates a noise component due to the (constant) rotation of the blades of the WTG, plus a wake-noise component that increases with the square of the power produced by the WTG. Mechanical sound from machinery, and low-frequency impulsive sounds produced by blade interaction with the wake of the support tower are not considered.

Keast, D. N.; Potter, R. C.

1980-07-01

310

Power generation and blade flow measurements of a full scale wind turbine  

NASA Astrophysics Data System (ADS)

Experimental research has been completed using a custom designed and built 4m wind turbine in a university operated wind facility. The primary goals of turbine testing were to determine the power production of the turbine and to apply the particle image velocimetry (PIV) technique to produce flow visualization images and velocity vector maps near the tip of a blade. These tests were completed over a wide range of wind speeds and turbine blade rotational speeds. This testing was also designed to be a preliminary study of the potential for future research using the turbine apparatus and to outline it's limitations. The goals and results of other large scale turbine tests are briefly discussed with a comparison outlining the unique aspects of the experiment outlined in this thesis. Power production tests were completed covering a range of mean wind speeds, 6.4 m/s to 11.1 m/s nominal, and rotational rates, 40 rpm to 220 rpm. This testing allowed the total power produced by the blades to be determined as a function of input wind speed, as traditionally found in power curves for commercial turbines. The coefficient of power, Cp, was determined as a function of the tip speed ratio which gave insight into the peak power production of the experimental turbine. It was found, as expected, that the largest power production occurred at the highest input wind speed, 11.1 m/s, and reached a mean value of 3080 W at a rotational rate of 220 rpm. Peak Cp was also found, as a function of the tip speed ratio, to approach 0.4 at the maximum measurable tip speed ratio of 8. Blade element momentum (BEM) theory was also implemented as an aerodynamic power and force prediction tool for the given turbine apparatus. Comparisons between the predictions and experimental results were made with a focus on the Cp power curve to verify the accuracy of the initial model. Although the initial predictions, based on lift and drag curves found in Abbot and Von Deonhoff 1, were similar to experimental results at high tip speed ratios an extrapolation of the data given by Hoffman et al. 2 was found to more closely match the experimental results over the full range of tip speed ratios. Finally PIV was used to produce flow visualization images and corresponding velocity maps of the chord-wise air flow over an area at a radius ratio of 0.9, near the tip of a blade. This technique provided insight into the flow over a blade at three different tip speed ratios, 4, 6 and 8, over a range of wind speeds and rotational rates. A discussion of the unique aspects and challenges encountered using the PIV technique is presented including: measuring an unbounded external flow on a rotating object and the turbulence in the free stream affecting the uniform seeding and stability of the flow.

Gaunt, Brian

311

A 200-kW wind turbine generator conceptual design study  

NASA Technical Reports Server (NTRS)

A conceptual design study was conducted to define a 200 kW wind turbine power system configuration for remote applications. The goal was to attain an energy cost of 1 to 2 cents per kilowatt-hour at a 14-mph site (mean average wind velocity at an altitude of 30 ft.) The costs of the Clayton, New Mexico, Mod-OA (200-kW) were used to identify the components, subsystems, and other factors that were high in cost and thus candidates for cost reduction. Efforts devoted to developing component and subsystem concepts and ideas resulted in a machine concept that is considerably simpler, lighter in weight, and lower in cost than the present Mod-OA wind turbines. In this report are described the various innovations that contributed to the lower cost and lighter weight design as well as the method used to calculate the cost of energy.

1979-01-01

312

Evaluation of human exposure to the noise from large wind turbine generators  

NASA Technical Reports Server (NTRS)

The human perception of a nuisance level of noise was quantified in tests and attempts were made to define criteria for acceptable sound levels from wind turbines. Comparisons were made between the sound necessary to cause building vibration, which occurred near the Mod-1 wind turbine, and human perception thresholds for building noise and building vibration. Thresholds were measured for both broadband and impulsive noise, with the finding that noise in the 500-2000 Hz region, and impulses with a 1 Hz fundamental, were most noticeable. Curves were developed for matching a receiver location with expected acoustic output from a machine to determine if the sound levels were offensive. In any case, further data from operating machines are required before definitive criteria can be established.

Shepherd, K. P.; Grosveld, F. W.; Stephens, D. G.

1983-01-01

313

Structural Load Alleviation Applied to Next Generation Aircraft and Wind Turbines  

NASA Technical Reports Server (NTRS)

Reducing the environmental impact of aviation is a goal of the Subsonic Fixed Wing Project under the Fundamental Aeronautics Program of NASAs Aeronautics Research Mission Directorate. Environmental impact of aviation is being addressed by novel aircraft configurations and materials that reduce aircraft weight and increase aerodynamic efficiency. NASA is developing tools to address the challenges of increased airframe flexibility created by wings constructed with reduced structural material and novel light-weight materials. This talk will present a framework and demonstration of a flight control system using optimal control allocation with structural load feedback and constraints to achieve safe aircraft operation. As wind turbines age, they become susceptible to many forms of blade degradation. Results will be presented on work in progress that uses adaptive contingency control for load mitigation in a wind turbine simulation with blade damage progression modeled.

Frost, Susan

2011-01-01

314

Shaken, not stirred: The recipe for a fish-friendly turbine  

SciTech Connect

It is generally agreed that injuries and mortalities among turbine-passed fish can result from several mechanisms, including rapid and extreme water pressure changes, cavitation, shear, turbulence, and mechanical injuries (strike and grinding). Advances in the instrumentation available for monitoring hydraulic conditions and Computational Fluid Dynamics (CFD) techniques now make it possible both to estimate accurately the levels of these potential injury mechanisms in operating turbines and to predict the levels in new turbine designs. This knowledge can be used to {open_quotes}design-out{close_quotes} the most significant injury mechanisms in the next generation of turbines. However, further improvements in turbine design are limited by a poor understanding of the levels of mechanical and hydraulic stresses that can be tolerated by turbine-passed fish. The turbine designers need numbers (biological criteria) that define a safety zone for fish within which pressures, shear forces, cavitation, and chance of mechanical strike are all at acceptable levels for survival. This paper presents the results of a literature review of fish responses to the types of biological stresses associated with turbine passage, as studied separately under controlled conditions in the laboratory rather than in combination at field sites. Some of the controlled laboratory and field studies reviewed here were bioassays carried out for reasons unrelated to hydropower production. Analysis of this literature was used to develop provisional biological criteria for hydroelectric turbine designers. These biological criteria have been utilized in the U.S. Department of Energy`s Advanced Hydropower Turbine System (AHTS) Program to evaluate the results of conceptual engineering designs and the potential value of future turbine models and prototypes.

Cada, G.F.

1997-03-01

315

Acoustic noise generation by the DOE/NASA MOD-1 wind turbine  

NASA Astrophysics Data System (ADS)

The results of a series of measurements taken over the past year of the acoustic emissions from the DOE/NASA MOD-1 Wind Turbine show the maximum acoustic energy is concentrated in the low frequency range, often below 100 Hz. The temporal as well as the frequency characteristics of the turbine sounds have been shown to be important since the MOD-1 is capable of radiating both coherent and incoherent noise. The coherent sounds are usually impulsive and are manifested in an averaged frequency domain plot as large numbers of discrete energy bands extending from the blade passage frequency to beyond 50 Hz on occasion. It is these impulsive sounds which are identified as the principal source of the annoyance to a dozen families living within 3 km of the turbine. The source of the coherent noise appears to be the rapid, unsteady blade loads encountered as the blade passes through the wake of the tower structure. Annoying levels are occasionally reached at nearby homes due to the interaction of the low frequency, high energy peaks in the acoustic impulses and the structural modes of the homes as well as by direct radiation outdoors. The peak levels of these impulses can be enhanced or subdued through complete propagation.

Kelley, N. D.

1981-05-01

316

Acoustic noise generation by the DOE/NASA MOD-1 wind turbine  

NASA Technical Reports Server (NTRS)

The results of a series of measurements taken over the past year of the acoustic emissions from the DOE/NASA MOD-1 Wind Turbine show the maximum acoustic energy is concentrated in the low frequency range, often below 100 Hz. The temporal as well as the frequency characteristics of the turbine sounds have been shown to be important since the MOD-1 is capable of radiating both coherent and incoherent noise. The coherent sounds are usually impulsive and are manifested in an averaged frequency domain plot as large numbers of discrete energy bands extending from the blade passage frequency to beyond 50 Hz on occasion. It is these impulsive sounds which are identified as the principal source of the annoyance to a dozen families living within 3 km of the turbine. The source of the coherent noise appears to be the rapid, unsteady blade loads encountered as the blade passes through the wake of the tower structure. Annoying levels are occasionally reached at nearby homes due to the interaction of the low frequency, high energy peaks in the acoustic impulses and the structural modes of the homes as well as by direct radiation outdoors. The peak levels of these impulses can be enhanced or subdued through complete propagation.

Kelley, N. D.

1981-01-01

317

ENVIRONMENTAL HYDRAULICS  

EPA Science Inventory

The thermal, chemical, and biological quality of water in rivers, lakes, reservoirs, and near coastal areas is inseparable from a consideration of hydraulic engineering principles: therefore, the term environmental hydraulics. In this chapter we discuss the basic principles of w...

318

Nonlinear Control of Wind Turbines with Hydrostatic Transmission Based on Takagi-Sugeno Model  

NASA Astrophysics Data System (ADS)

A nonlinear model-based control concept for wind turbines with hydrostatic transmission is proposed. The complete mathematical model of a wind turbine drive train with variable displacement pump and variable displacement motor is presented. The controller design takes into consideration the nonlinearity of the aerodynamic maps and hydrostatic drive train by an convex combination of state space controller with measurable generator speed and hydraulic motor displacement as scheduling parameters. The objectives are the set point control of generator speed and tracking control of the rotor speed to reach the maximum power according to the power curve in the partial-load region.

Schulte, Horst; Georg, Soren

2014-06-01

319

CFD investigating thermal-hydraulic characteristics and hydrogen generation from graphite–water reaction after SG tube rupture in HTR-10 reactor  

Microsoft Academic Search

With inherent safety performance and high conversion efficiency, high-temperature gas-cooled reactors are the possible candidates for next-generation energy sources. A transient three-dimensional compressible CFD model is developed to investigate the thermal-hydraulic characteristics within the core under steady-state and accident conditions. The HTR-10, a graphite-moderated and helium-cooled reactor with a pebble bed core is selected for the present simulations. Four postulated

Y. M. Ferng; C. T. Chen

2011-01-01

320

Heat Transfer and Flow on the First Stage Blade Tip of a Power Generation Gas Turbine. Part 1; Experimental Results  

NASA Technical Reports Server (NTRS)

A combined computational and experimental study has been performed to investigate the detailed distribution of convective heat transfer coefficients on the first stage blade tip surface for a geometry typical of large power generation turbines(>100MW). This paper is concerned with the design and execution of the experimental portion of the study. A stationary blade cascade experiment has been run consisting of three airfoils, the center airfoil having a variable tip gap clearance. The airfoil models the aerodynamic tip section of a high pressure turbine blade with inlet Mach number of 0.30, exit Mach number of 0.75, pressure ratio of 1.45, exit Reynolds number based on axial chord of 2.57 x 10(exp 6), and total turning of about 110 degrees. A hue detection based liquid crystal method is used to obtain the detailed heat transfer coefficient distribution on the blade tip surface for flat, smooth tip surfaces with both sharp and rounded edges. The cascade inlet turbulence intensity level took on values of either 5% or 9%. The cascade also models the casing recess in the shroud surface ahead of the blade. Experimental results are shown for the pressure distribution measurements on the airfoil near the tip gap, on the blade tip surface, and on the opposite shroud surface. Tip surface heat transfer coefficient distributions are shown for sharp-edge and rounded-edge tip geometries at each of the inlet turbulence intensity levels.

Bunker, Ronald S.; Bailey, Jeremy C.; Ameri, Ali A.

1999-01-01

321

A New Non-gaussian Turbulent Wind Field Generator to Estimate Design-Loads of Wind-Turbines  

NASA Astrophysics Data System (ADS)

Climate change and finite fossil fuel resources make it urgent to turn into electricity generation from mostly renewable energies. One major part will play wind-energy supplied by wind-turbines of rated power up to 10 MW. For their design and development wind field models have to be used. The standard models are based on the empirical spectra, for example by von Karman or Kaimal. From investigation of measured data it is clear that gusts are underrepresented in such models. Based on some fundamental discoveries of the nature of turbulence by Friedrich [1] derived from the Navier-Stokes equation directly, we used the concept of Continuous Time Random Walks to construct three dimensional wind fields obeying non-Gaussian statistics. These wind fields were used to estimate critical fatigue loads necessary within the certification process. Calculations are carried out with an implementation of a beam-model (FLEX5) for two types of state-of-the-art wind turbines The authors considered the edgewise and flapwise blade-root bending moments as well as tilt moment at tower top due to the standard wind field models and our new non-Gaussian wind field model. Clear differences in the loads were found.

Schaffarczyk, A. P.; Gontier, H.; Kleinhans, D.; Friedrich, R.

322

Wind Turbinie Generator System Power Performance Test Report for the Mariah Windspire 1-kW Wind Turbine  

SciTech Connect

This report summarizes the results of a power performance test that NREL conducted on the Mariah Windspire 1-kW wind turbine. During this test, two configurations were tested on the same turbine. In the first configuration, the turbine inverter was optimized for power production. In the second configuration, the turbine inverter was set for normal power production. In both configurations, the inverter experienced failures and the tests were not finished.

Huskey, A.; Bowen, A.; Jager, D.

2009-12-01

323

Design of a hybrid battery charger system fed by a wind-turbine and photovoltaic power generators  

Microsoft Academic Search

This paper is aimed to develop a digital signal processor (DSP) for controlling a solar cell and wind-turbine hybrid charging system. The DSP consists of solar cells, a wind turbine, a lead acid battery, and a buck-boost converter. The solar cells and wind turbine serve as the system's main power sources and the battery as an energy storage element. The

Jia-Ren Chang Chien; Kuo-Ching Tseng; Bo-Yi Yan

2011-01-01

324

Hydraulics Lectures  

NSDL National Science Digital Library

This page from the WindTech TV project provides a link to lectures created by Jim Pytel for his hydraulics course at Columbia Gorge Community College. The lectures consist of live videos and screen capture style presentations and may be viewed free of charge. Clicking on the video link in the center of the page will lead users to a YouTube page with 31 lectures. Topics include hydraulics math, hydraulic safety, basic hydraulic schematics, viscosity, piston pumps, actuators, troubleshooting and more. These lectures would be extremely useful for technical and community college students taking a fundamental hydraulics course. Flash is required to view the videos.

Pytel, Jim

325

Heat Transfer and Flow on the First Stage Blade Tip of a Power Generation Gas Turbine. Part 2; Simulation Results  

NASA Technical Reports Server (NTRS)

A combined experimental and computational study has been performed to investigate the detailed distribution of convective heat transfer coefficients on the first stage blade tip surface for a geometry typical of large power generation turbines (>1OOMW). This paper is concerned with the numerical prediction of the tip surface heat transfer. Good comparison with the experimental measured distribution was achieved through accurate modeling of the most important features of the blade passage and heating arrangement as well as the details of experimental rig likely to affect the tip heat transfer. A sharp edge and a radiused edge tip were considered. The results using the radiused edge tip agreed better with the experimental data. This improved agreement was attributed to the absence of edge separation on the tip of the radiused edge blade.

Ameri, A. A.; Bunker, R. S.

1999-01-01

326

Coal-gasification/MHD/steam-turbine combined-cycle (GMS) power generation  

SciTech Connect

The coal-gasification/MHD/steam-turbine combined cycle (GMS) refers to magnetohydrodynamic (MHD) systems in which coal gasification is used to supply a clean fuel (free of mineral matter and sulfur) for combustion in an MHD electrical power plant. Advantages of a clean-fuel system include the elimination of mineral matter or slag from all components other than the coal gasifier and gas cleanup system; reduced wear and corrosion on components; and increased seed recovery resulting from reduced exposure of seed to mineral matter or slag. Efficiencies in some specific GMS power plants are shown to be higher than for a comparably sized coal-burning MHD power plant. The use of energy from the MHD exhaust gas to gasify coal (rather than the typical approach of burning part of the coal) results in these higher efficiencies.

Lytle, J.M.; Marchant, D.D.

1980-11-01

327

Fiberglass composite blades for the 2 MW Mod-1 wind turbine generator  

NASA Astrophysics Data System (ADS)

In mid-1979, NASA contracted with Kaman Aerospace Corporation for the design, manufacture, and ground testing of two 100 foot composite rotor blades intended for operation on the Mod-1 wind turbine. The Mod-1 blades have been completed and are currently stored at the Kaman facility. The design, tooling, fabrication, and testing phases which have been carried out to date, as well as testing still planned are described. Discussed are differences from the 150 foot blade which were introduced for cost and manufacturing improvement purposes. Also included is a description of the lightning protection system installed in the blades, and its development program. Actual costs and manhours expended for Blade No. 2 are provided as a base, along with a projection of costs for the blade in production. Finally, cost drivers are identified relative to future designs.

Batesole, W. R.

328

Wind turbine generator application places unique demands on tower design and materials  

NASA Technical Reports Server (NTRS)

The most relevant contractual tower design requirements and goal for the Mod-1 tower are related to steel truss tower construction, cost-effective state-of-the-art design, a design life of 30 years, and maximum wind conditions of 120 mph at 30 feet elevation. The Mod-1 tower design approach was an iterative process. Static design loads were calculated and member sizes and overall geometry chosen with the use of finite element computer techniques. Initial tower dynamic characteristics were then combined with the dynamic properties of the other wind turbine components, and a series of complex dynamic computer programs were run to establish a dynamic load set and then a second tower design.

Kita, J. P.

1978-01-01

329

A Study on the Observation of Direct Lightning Current through the Wind Turbine Generator System in the Coast of the Japan Sea  

NASA Astrophysics Data System (ADS)

As clean energy that solves energy resources, many wind turbine generator systems have developed up to now, in Japan. The generation capacity of wind power is above 1 million kW, and the construction also continues from now on. The wind turbine generator systems are built in the good place of the wind condition, and those many are built on the coast of the Japan Sea. However, the coast of the Japan Sea is known as a place with much winter lightning, and wind turbine generator systems also often suffer the damage by winter lightning. The authors observed the lightning current that strikes through the wind turbine generator systems directly, in order to establish on the lightning protection of them. The authors acquired dozens of data as a result of observation in Akita Japan for 17 months. Based on these data, some considerations were performed about the performance of winter lightning that struck through the wind turbine generator systems. As the result of consideration, we found some interesting knowledge following sentence. It made clear anew that the tower which is a place of high position from the ground and on the windward has much number of lightning flash and many total flash charges. The lightning stroke current divided the tower pipe and ground leads. About 70% of the observed lightning current flowed to the tower pipe, and about 30% is divided into two grounding leads connected to the leg of tower. All of steep current that is on a wave front flow a tower side, it dose not flow to a grounding leads side. The distributions of lightning parameters between our observation results and past one are in good conformity.

Shiraishi, Yasuhiro; Otsuka, Takahiro; Matsuura, Hideki

330

Heat transfer and flow on the first-stage blade tip of a power generation gas turbine: Part 2 -- Simulation results  

Microsoft Academic Search

A combined experimental and computational study has been performed to investigate the detailed distribution of convective heat transfer coefficients on the first-stage blade tip surface for a geometry typical of large power generation turbines (> 100 MW). This paper is concerned with the numerical prediction of the tip surface heat transfer. Good comparison with the experimental measured distribution was achieved

A. A. Ameri; R. S. Bunker

2000-01-01

331

Heat transfer and flow on the first-stage blade tip of a power generation gas turbine: Part 1 -- Experimental results  

Microsoft Academic Search

A combined experimental and computational study has been performed to investigate the detailed distribution of convective heat transfer coefficients on the first-stage blade tip surface for a geometry typical of large power generation turbines (> 100 MW). This paper is concerned with the design and execution of the experimental portion of the study, which represents the first reported investigation to

Ronald S. Bunker; Jeremy C. Bailey; Ali A. Ameri

2000-01-01

332

The Performance Analysis of Ultra High Speed PM Type Synchronous Motor-Generator for Micro Turbine  

NASA Astrophysics Data System (ADS)

This paper deals with loss analysis, structural, thermal-fluid and rotordynamics (critical speed and unbalance) which need in developing the motor-generator. This machine has designed of a generator of 800 W, 400 krpm and a starter of 400 W, 200 krpm. The generated losses of motor-generator are derived by magnetic analysis. Thermal-fluid analysis is performed using loss analysis result. The critical speed is extracted by Campbell diagram. Unbalance vibration response analysis enable to predict the expected vibration amplitude by unbalance. The motor-generator is well-developed using the applied several techniques of analysis.

Hong, Do-Kwan; Woo, Byung-Chul; Jeong, Yeon-Ho; Koo, Dae-Hyun; Cho, Yun-Hyun

333

Failure analysis of a Francis turbine runner  

NASA Astrophysics Data System (ADS)

The variable demand on the energy market requires great flexibility in operating hydraulic turbines. Therefore, turbines are frequently operated over an extended range of regimes. Francis turbines operating at partial load present pressure fluctuations due to the vortex rope in the draft tube cone. This phenomenon generates strong vibrations and noise that may produce failures on the mechanical elements of the machine. This paper presents the failure analysis of a broken Francis turbine runner blade. The failure appeared some months after the welding repair work realized in situ on fatigue cracks initiated near to the trailing edge at the junction with the crown, where stress concentration occurs. In order to determine the causes that led to the fracture of the runner blade, the metallographic investigations on a sample obtained from the blade is carried out. The metallographic investigations included macroscopic and microscopic examinations, both performed with light and scanning electron microscopy, as well as EDX - analyses. These investigations led to the conclusion, that the cracking of the blade was caused by fatigue, initiated by the surface unevenness of the welding seam. The failure was accelerated by the hydrogen embrittlement of the filling material, which appeared as a consequence of improper welding conditions. In addition to the metallographic investigations, numerical computations with finite element analysis are performed in order to evaluate the deformation and stress distribution on blade.

Frunz?verde, D.; Muntean, S.; M?rginean, G.; Câmpian, V.; Mar?avina, L.; Terzi, R.; ?erban, V.

2010-08-01

334

Synthetic Vortex Generator Jets Used to Control Separation on Low-Pressure Turbine Airfoils  

NASA Technical Reports Server (NTRS)

Low-pressure turbine (LPT) airfoils are subject to increasingly stronger pressure gradients as designers impose higher loading in an effort to improve efficiency and lower cost by reducing the number of airfoils in an engine. When the adverse pressure gradient on the suction side of these airfoils becomes strong enough, the boundary layer will separate. Separation bubbles, particularly those that fail to reattach, can result in a significant loss of lift and a subsequent degradation of engine efficiency. The problem is particularly relevant in aircraft engines. Airfoils optimized to produce maximum power under takeoff conditions may still experience boundary layer separation at cruise conditions because of the thinner air and lower Reynolds numbers at altitude. Component efficiency can drop significantly between takeoff and cruise conditions. The decrease is about 2 percent in large commercial transport engines, and it could be as large as 7 percent in smaller engines operating at higher altitudes. Therefore, it is very beneficial to eliminate, or at least reduce, the separation bubble.

Ashpis, David E.; Volino, Ralph J.

2005-01-01

335

ANS sixth proceedings of the nuclear thermal hydraulics  

SciTech Connect

This book is covered under the following topics: Thermal Hydraulics of Severe Accidents; Thermal Hydraulics of Noncommercial Reactors; Thermal Hydraulic Aspects of Passive Safety and New-Generation Reactors; Method s In Reactor Physics and Thermal Hydraulics; Thermal Hydraulics - Numerical Techniques In Reactor System Thermal Hydraulic; Advancements In Radionuclide Thermal Hydraulics; Fundamentals of Two-Phase Flows; and Natural Circulation In Reactor Systems-I-II.

Not Available

1990-01-01

336

Integration of permanent magnet synchronous generator wind turbines into power grid  

Microsoft Academic Search

The world is seeing an ever-increasing demand for electrical energy. The future growth of electrical power generation needs to be a mix of technologies including fossil fuels, hydro, nuclear, wind, and solar. The federal and state energy agencies have taken several proactive steps to increase the share of renewable energy in the total generated electrical power. In 2005, 11.1% of

Asghar Abedini

2008-01-01

337

Design of optimal PI controllers for doubly fed induction generators in wind turbines using genetic algorithm  

Microsoft Academic Search

This paper presents a design procedure based on evolutionary computation, more specifically on genetic algorithm (GA) to obtain optimal PI controllers to the static converter connected to the rotor of doubly fed induction generators (DFIGpsilas), in variable speed wind generation systems connected to the electrical grid. The converter of the DFIG has a protection system that monitors continuously the machine

João P. A. Vieira; Marcus N. A. Nunes; Ubiratan H. Bezerra

2008-01-01

338

Cost competitive 30 kW gas turbine\\/generator demonstration for cogeneration or solar-electric applications  

Microsoft Academic Search

The author demonstrates the performance of a Brayton-cycle gas turbine engine. The Brayton cycle studied is a highly recuperated, low-pressure-ratio, two-shaft open cycle. The novelty in this approach is that the turbine engine was composed of stock turbocharger components. Internal combustion occurs between the compressor and turbine of the gasifier section. The surplus energy exhausted from the gasifier drives the

J. B. Kesseli; A. Wells

1989-01-01

339

Constructing a Plastic Bottle Wind Turbine as a Practical Aid for Learning about Using Wind Energy to Generate Electricity  

ERIC Educational Resources Information Center

A simple horizontal axis wind turbine can be easily constructed using a 1.5 l PET plastic bottle, a compact disc and a small dynamo. The turbine operates effectively at low wind speeds and has a rotational speed of 500 rpm at a wind speed of about 14 km h[superscript -1]. The wind turbine can be used to demonstrate the relationship between open…

Appleyard, S. J.

2009-01-01

340

Second-Generation Pressurized Fluidized Bed Combustion: Small gas turbine industrial plant study  

SciTech Connect

Second-Generation Pressurized Fluidized Bed Combustion (PFBC) plants provide a coal-fired, high-efficiency, combined-cycle system for the generation of electricity and steam. The plants use lime-based sorbents in PFB combustors to meet environmental air standards without back-end gas desulfurization equipment. The second-generation system is an improvement over earlier PFBC concepts because it can achieve gas temperatures of 2100{degrees}F and higher for improved cycle efficiency while maintaining the fluidized beds at 1600{degrees}F for enhanced sulfur capture and minimum alkali release. Second-generation PFBC systems are capable of supplying the electric and steam process needs of industrial plants. The basic second-generation system can be applied in different ways to meet a variety of process steam and electrical requirements. To evaluate the potential of these systems in the industrial market, conceptual designs have been developed for six second-generation PFBC plants. These plants cover a range of electrical outputs from 6.3 to 41.5 MWe and steam flows from 46,067 to 442,337 lb/h. Capital and operating costs have been estimated for these six plants and for equivalent (in size) conventional, coal-fired atmospheric fluidized bed combustion cogeneration plants. Economic analyses were conducted to compare the cost of steam for both the second-generation plants and the conventional plants.

Shenker, J.; Garland, R.; Horazak, D.; Seifert, F.; Wenglarz, R.

1992-07-01

341

Second-Generation Pressurized Fluidized Bed Combustion: Small gas turbine induustrial plant study  

SciTech Connect

Second-Generation Pressurized Fluidized Bed Combustion (PFBC) plants provide a coal-fired, high-efficiency, combined-cycle system for the generation of electricity and steam. The plants use lime-based sorbents in PFB combustors to meet environmental air standards without back-end gas desulfurization equipment. The second-generation system is an improvement over earlier PFBC concepts because it can achieve gas temperatures of 2100[degrees]F and higher for improved cycle efficiency while maintaining the fluidized beds at 1600[degrees]F for enhanced sulfur capture and minimum alkali release. Second-generation PFBC systems are capable of supplying the electric and steam process needs of industrial plants. The basic second-generation system can be applied in different ways to meet a variety of process steam and electrical requirements. To evaluate the potential of these systems in the industrial market, conceptual designs have been developed for six second-generation PFBC plants. These plants cover a range of electrical outputs from 6.3 to 41.5 MWe and steam flows from 46,067 to 442,337 lb/h. Capital and operating costs have been estimated for these six plants and for equivalent (in size) conventional, coal-fired atmospheric fluidized bed combustion cogeneration plants. Economic analyses were conducted to compare the cost of steam for both the second-generation plants and the conventional plants.

Shenker, J.; Garland, R.; Horazak, D.; Seifert, F.; Wenglarz, R.

1992-07-01

342

Simulation for Wind Turbine Generators -- With FAST and MATLAB-Simulink Modules  

SciTech Connect

This report presents the work done to develop generator and gearbox models in the Matrix Laboratory (MATLAB) environment and couple them to the National Renewable Energy Laboratory's Fatigue, Aerodynamics, Structures, and Turbulence (FAST) program. The goal of this project was to interface the superior aerodynamic and mechanical models of FAST to the excellent electrical generator models found in various Simulink libraries and applications. The scope was limited to Type 1, Type 2, and Type 3 generators and fairly basic gear-train models. Future work will include models of Type 4 generators and more-advanced gear-train models with increased degrees of freedom. As described in this study, implementation of the developed drivetrain model enables the software tool to be used in many ways. Several case studies are presented as examples of the many types of studies that can be performed using this tool.

Singh, M.; Muljadi, E.; Jonkman, J.; Gevorgian, V.; Girsang, I.; Dhupia, J.

2014-04-01

343

Kaman 40 kW wind turbine generator - control system dynamics  

NASA Technical Reports Server (NTRS)

The generator design incorporates an induction generator for application where a utility line is present and a synchronous generator for standalone applications. A combination of feed forward and feedback control is used to achieve synchronous speed prior to connecting the generator to the load, and to control the power level once the generator is connected. The dynamics of the drive train affect several aspects of the system operation. These were analyzed to arrive at the required shaft stiffness. The rotor parameters that affect the stability of the feedback control loop vary considerably over the wind speed range encountered. Therefore, the controller gain was made a function of wind speed in order to maintain consistent operation over the whole wind speed range. The velocity requirement for the pitch control mechanism is related to the nature of the wind gusts to be encountered, the dynamics of the system, and the acceptable power fluctuations and generator dropout rate. A model was developed that allows the probable dropout rate to be determined from a statistical model of wind gusts and the various system parameters, including the acceptable power fluctuation.

Perley, R.

1981-01-01

344

Kaman 40 kW wind turbine generator - control system dynamics  

NASA Astrophysics Data System (ADS)

The generator design incorporates an induction generator for application where a utility line is present and a synchronous generator for standalone applications. A combination of feed forward and feedback control is used to achieve synchronous speed prior to connecting the generator to the load, and to control the power level once the generator is connected. The dynamics of the drive train affect several aspects of the system operation. These were analyzed to arrive at the required shaft stiffness. The rotor parameters that affect the stability of the feedback control loop vary considerably over the wind speed range encountered. Therefore, the controller gain was made a function of wind speed in order to maintain consistent operation over the whole wind speed range. The velocity requirement for the pitch control mechanism is related to the nature of the wind gusts to be encountered, the dynamics of the system, and the acceptable power fluctuations and generator dropout rate. A model was developed that allows the probable dropout rate to be determined from a statistical model of wind gusts and the various system parameters, including the acceptable power fluctuation.

Perley, R.

1981-05-01

345

Hydraulic Car  

NSDL National Science Digital Library

In this activity, learners build cars using syringes and water-powered hydraulics. Learners construct the car frame out of cardboard and set up a hydraulic system to raise and lower the car. Use this project to introduce learners to incompressible fluids and Pascal's Principle.

2014-09-12

346

Rampressor Turbine Design  

SciTech Connect

The design of a unique gas turbine engine is presented. The first Rampressor Turbine engine rig will be a configuration where the Rampressor rotor is integrated into an existing industrial gas turbine engine. The Rampressor rotor compresses air which is burned in a traditional stationary combustion system in order to increase the enthalpy of the compressed air. The combustion products are then expanded through a conventional gas turbine which provides both compressor and electrical power. This in turn produces shaft torque, which drives a generator to provide electricity. The design and the associated design process of such an engine are discussed in this report.

Ramgen Power Systems

2003-09-30

347

Combined molten carbonate fuel cell and gas turbine systems for efficient power and heat generation using biomass  

Microsoft Academic Search

When used in combination with turbines, fuel cells can produce from 55 to 90% of the electricity of the system while turbines produce the remainder. Fuel flexibility enables the use of low-cost indigenous fuels, renewables, and waste materials. The characteristics of gas from biomass gasification may vary significantly. Most real systems cannot be modeled exactly. Errors arise from unmodeled or

Francisco Jurado; Manuel Valverde

2003-01-01

348

Turbinate surgery  

MedlinePLUS

Turbinectomy; Turbinoplasty; Turbinate reduction; Nasal airway surgery ... There are several types of turbinate surgery: Turbinectomy: All or part of the lower turbinate is taken out. This can be done in several different ways, but sometimes a ...

349

Simulation of a Doubly-Fed Induction Generator with hydro turbine for electrical energy production  

Microsoft Academic Search

In this paper, the authors propose a behaviour simulation of a micro power station system for electric power generation in isolated equatorial regions, e.g. Africa and South America. These remote areas have usually a good potential of hydroelectric relative to small community or activity need. They are characterized by sufficient rainfall, which leads to the steady average flow of the

M. B. Camara; B. Dakyo; C. Nichita; G. Barakat

2009-01-01

350

Development and demonstration of a vertical axis wind turbine POWERHOUSE  

NASA Astrophysics Data System (ADS)

A performance of reliable lower cost base assembly and controls was designed for the electricity generating wind energy conversion system of the VAWTPOWER 185 wind turbine. The base assembly includes low speed shaft and couplings, disc or drum brake, hydraulic or pneumatic brake control systems, speed increasing gear box, high speed shaft and couplings, induction motor/generator, bottom rotor bearings, lightning and ground fault protection, support structure, and environmental protection. VAWTPOWER 185 is a 200 kW capacity Vertical Axis Wind Turbine rated 185 kW at 37 mph. After system analysis, subsystem definition, detailed design and engineering, and development of a test plan, two versions of the powerhouse were fabricated and tested. Both appear ready for commercial production.

Vosburgh, P. N.

1984-06-01

351

Airship-floated wind turbine  

SciTech Connect

A wind turbine, by use of a tethered airship for support, may be designed for the economical recovery of power at heights of 2,000 feet or more above ground, at which height power density in the wind is typically three times the power density available to a conventionally supported wind turbine. Means can be added to such an airship-floated wind turbine which will permit its generators to be used to meet load demand even during periods of little or no wind. Described to this end is a wind turbine system which combines, among other novel features: a novel tether line system which provides access for men and materials to the supporting airship while in active service, a novel system for providing additional buoyant lift at the nose of the turbine-supporting airship to offset the vertical component of tension induced in the tether line by the downwind force exerted by the turbine blades, a novel bearing assembly at the nose of the supporting airship which permits the airship to rotate as a unit with the turbine it supports without causing a similar rotation of the tether line, a novel turbine airship structure which handles concentrated loads from the turbine efficiently and also permits the safe use of hydrogen for buoyancy, a novel ''space frame'' structure which supports the turbine blades and greatly reduces blade weight, a novel system for controlling turbine blade angle of incidence and for varying blade incidene in synchrony with blade angular position abut the turbine axis to provide greater control over airship movement, a novel system for locating propellor-driven generators out at the wind turbine perimeter and for using lightweight, high-RPM generators to produce electrical energy at a power line frequency, which greatly reduces the weight required to convert turbine blade torque into useful power, and a novel system for incorporating compressed air storage and combustion turbine components into the wind turbine's generator drive systems.

Watson, W. K.

1985-01-01

352

DESIGN, FABRICATION, AND TESTING OF AN ADVANCED, NON-POLLUTING TURBINE DRIVE GAS GENERATOR  

SciTech Connect

The objectives of this report period were to continue and complete testing of the Gas Generator hardware, to complete and submit a Draft Final Report, and after incorporation of adjustments required, to then submit the Final Report. Focus during this report period was initially on testing the Gas Generator. While conducting scheduled full power tests of the Gas Generator at the facilities of the testing sub-contractor, National Testing Services [NTS], in Santa Clarita CA, anomalies in the performance of the Gas Generator were discovered. All testing was stopped on November 6, 2002. An expert team was formed to evaluate the anomalies and to recommend any appropriate corrective actions. After extensive analyses of the actual hardware, the test data acquired and recorded during testing, and a review of the test facilities and procedures, the Anomalies Review Team recommended that CES modify the combustion chamber front end cooling method and modify the configuration of the diluent injectors downstream of the combustion chamber, to eliminate the anomalies. At a review meeting convened in Sacramento CA on November 23, 2002, outside experts from the Lawrence Livermore National Laboratory, Air Liquide's Research Center in Chicago IL, and the California Energy Commission, confirmed that the expert team's assessed cause of the problem was the likely cause, and the recommended corrective actions were appropriate. Modified hardware drawings were produced in late November-early December 2002, hardware fabrication was begun in December, and was in process at the end of December. Also during December, the NTS test facility was being adjusted to take account of the modified hardware configuration being produced. All work was aimed toward realizing a schedule of resumed testing by mid-January for completion of tests by end of January or early February, 2003. Original objectives of the program remain in place and approximately ninety (90) percent of those objectives had been completed prior to discovery of the anomalies. The accomplished objectives to date are described in this report.

Stephen E. Doyle

2002-12-31

353

Three-Dimensional Measurements of Fuel Distribution in High-Pressure, High- Temperature, Next-Generation Aviation Gas Turbine Combustors  

NASA Technical Reports Server (NTRS)

In our world-class, optically accessible combustion facility at the NASA Lewis Research Center, we have developed the unique capability of making three-dimensional fuel distribution measurements of aviation gas turbine fuel injectors at actual operating conditions. These measurements are made in situ at the actual operating temperatures and pressures using the JP-grade fuels of candidate next-generation advanced aircraft engines for the High Speed Research (HSR) and Advanced Subsonics Technology (AST) programs. The inlet temperature and pressure ranges used thus far are 300 to 1100 F and 80 to 250 psia. With these data, we can obtain the injector spray angles, the fuel mass distributions of liquid and vapor, the degree of fuel vaporization, and the degree to which fuel has been consumed. The data have been used to diagnose the performance of injectors designed both in-house and by major U.S. engine manufacturers and to design new fuel injectors with overall engine performance goals of increased efficiency and reduced environmental impact. Mie scattering is used to visualize the liquid fuel, and laser-induced fluorescence is used to visualize both liquid and fuel vapor.

Hicks, Yolanda R.; Locke, Randy J.; Anderson, Robert C.; Zaller, Michelle M.

1998-01-01

354

Single rotor turbine engine  

DOEpatents

There has been invented a turbine engine with a single rotor which cools the engine, functions as a radial compressor, pushes air through the engine to the ignition point, and acts as an axial turbine for powering the compressor. The invention engine is designed to use a simple scheme of conventional passage shapes to provide both a radial and axial flow pattern through the single rotor, thereby allowing the radial intake air flow to cool the turbine blades and turbine exhaust gases in an axial flow to be used for energy transfer. In an alternative embodiment, an electric generator is incorporated in the engine to specifically adapt the invention for power generation. Magnets are embedded in the exhaust face of the single rotor proximate to a ring of stationary magnetic cores with windings to provide for the generation of electricity. In this alternative embodiment, the turbine is a radial inflow turbine rather than an axial turbine as used in the first embodiment. Radial inflow passages of conventional design are interleaved with radial compressor passages to allow the intake air to cool the turbine blades.

Platts, David A. (Los Alamos, NM)

2002-01-01

355

Hydraulics of open channel flow  

Microsoft Academic Search

``Hydraulics of Open Channel Flow'' provides a complete understanding of open channel flow phenomena, and clearly explains the methods for solving the theoretical equations that represent these phenomena. Researchers and practicing engineers in charge of design of hydraulics structures, generation of hydropower, and computation of pollutant diffusion in channels and lakes will find in this essential reference a wealth of

Sergio Montes

1998-01-01

356

Sound measurements and observations of the MOD-OA wind turbine generator  

NASA Technical Reports Server (NTRS)

Sound measurements are reported for a wind velocity of about 5 m/s and a power output of about 70 kW. Both broadband and narrowband data were obtained for a range of distances and azimuth angles from the machine. Both discrete frequency and broadband components were identified. Loading harmonics at multiples of the blade passage frequency and electrical generator harmonics at multiples of the shaft speed dominated the spectrum below 100 Hz. The 10,000 Hz peak is believed to be of mechanical origin in the nacelle and the other arises from blade aerodynamic sources. Aural detection distances of about 525 m upwind and 850 downwind were observed.

Shepherd, K. P.; Hubbard, H. H.

1982-01-01

357

Limited energy study, low pressure turbine Fort Wainwright, Alaska. Final report  

SciTech Connect

The purpose of the study is to evaluate the installation of a low pressure, condensing turbine generator at Ft Wainwright Power Plant (Power Plant). The low pressure turbine generator would be installed downstream of an existing backpressure (10 psig exhaust) turbine generator. Although not specifically in the scope of work, EMC also evaluated replacing the existing backpressure turbine generator with a condensing turbine generator.

NONE

1995-02-01

358

Development of a more fish-tolerant turbine runner, advanced hydropower turbine project  

SciTech Connect

Alden Research Laboratory, Inc. (ARL) and Northern Research and Engineering Corporation (NREC) conducted a research program to develop a turbine runner which will minimize fish injury and mortality at hydroelectric projects. ARL?NREC have developed a runner shape which minimizes the number of blade leading edges, reduces the pressure versus time and the velocity versus distance gradients within the runner, minimizes or eliminates the clearance between the runner and runner housing, and maximizes the size of the flow passages, all with minimal penalty on turbine efficiency. An existing pump impeller provided the starting point for developing the fish tolerant turbine runner. The Hidrostal pump is a single bladed combined screw/centrifugal pump which has been proven to transport fish with minimal injury. The focus of the ARL/NREC research project was to develop a new runner geometry which is effective in downstream fish passage and hydroelectric power generation. A flow of 1,000 cfs and a head in the range of 75 ft to 100 ft were selected for conceptual design of the new runner. Conceptual design of the new runner began with a re-evaluation of studies which have been previously conducted to identify probable sources of injury to fish passing through hydraulic turbines. Criteria relative to hydraulic characteristics which are favorable for fish passage were prepared based on a reassessment of the available information. Important criteria used to develop the new runner design included low pressure change rates, minimum absolute pressures, and minimum shear. Other criteria which are reflected in the runner design are a minimum number of blades (only two), minimum total length of leading edges, and large flow passages. 86 figs., 5 tabs.

Cook, T.C.; Hecker, G.E. [Worcester Polytechnic Inst., Holden, MA (United States). Alden Research Lab.; Faulkner, H.B.; Jansen, W. [Northern Research and Engineering Corp., Woburn, MA (United States)

1997-02-01

359

Effect of water injection and off scheduling of variable inlet guide vanes, gas generator speed and power turbine nozzle angle on the performance of an automotive gas turbine engine  

NASA Technical Reports Server (NTRS)

The Chrysler/ERDA baseline automotive gas turbine engine was used to experimentally determine the power augmentation and emissions reductions achieved by the effect of variable compressor and power engine geometry, water injection downstream of the compressor, and increases in gas generator speed. Results were dependent on the mode of variable geometry utilization. Over 20 percent increase in power was accompanied by over 5 percent reduction in SFC. A fuel economy improvement of at least 6 percent was estimated for a vehicle with a 75 kW (100 hp) engine which could be augmented to 89 kW (120 hp) relative to an 89 Kw (120 hp) unaugmented engine.

Warren, E. L.

1980-01-01

360

Optimization design of wind turbine drive train based on Matlab genetic algorithm toolbox  

NASA Astrophysics Data System (ADS)

In order to ensure the high efficiency of the whole flexible drive train of the front-end speed adjusting wind turbine, the working principle of the main part of the drive train is analyzed. As critical parameters, rotating speed ratios of three planetary gear trains are selected as the research subject. The mathematical model of the torque converter speed ratio is established based on these three critical variable quantity, and the effect of key parameters on the efficiency of hydraulic mechanical transmission is analyzed. Based on the torque balance and the energy balance, refer to hydraulic mechanical transmission characteristics, the transmission efficiency expression of the whole drive train is established. The fitness function and constraint functions are established respectively based on the drive train transmission efficiency and the torque converter rotating speed ratio range. And the optimization calculation is carried out by using MATLAB genetic algorithm toolbox. The optimization method and results provide an optimization program for exact match of wind turbine rotor, gearbox, hydraulic mechanical transmission, hydraulic torque converter and synchronous generator, ensure that the drive train work with a high efficiency, and give a reference for the selection of the torque converter and hydraulic mechanical transmission.

Li, R. N.; Liu, X.; Liu, S. J.

2013-12-01

361

Flooded areas assessment by integrating hydraulic flood analysis to the detailed flood maps generated with a multi-temporal image segmentation approach using Cosmo-Skymed  

NASA Astrophysics Data System (ADS)

The support of Earth Observation Systems to flood monitoring and damage assessment has been evaluated by integrating skills and knowledge of hydrologists and experts on image processing. Detailed flood maps are generated from the analysis of images pairs acquired by Cosmo-Skymed on the same area at different times. The adopted methodology applies image pre-processing and segmentation techniques with a multi-temporal approach. After noise reduction by despeckling, the user manually localizes few water points in one image. From selected points, segmentation distinguishes the classes of flood, permanent-water and no-change areas. Then, an anisotropic scanning analyzes the images to define its content. The resulting connected regions are converted into vectors to be entered as constraint for a Physically based 2-D hydraulic flood model. The model recursively varies the unknown boundary conditions to match at best the areas extracted from Cosmo-Skymed. The product is a hydraulic consistent report of the flooded area including information on water depth and velocities. By combining these information with vulnerability maps, extracted from optical satellite images with a supervised approach, an estimation of the damage is provided. The reported results refer to the monitoring of the flood event occurred in the Scutari Lake area (Albania, January 2010).

Boni, G.; Angiati, E.; Candela, L.; Dellepiane, S.; Macchiavello, G.; Rudari, R.

2010-10-01

362

An integrated system combining chemical looping hydrogen generation process and solid oxide fuel cell/gas turbine cycle for power production with CO2 capture  

NASA Astrophysics Data System (ADS)

In this paper, the solid oxide fuel cell/gas turbine (SOFC/GT) cycle is integrated with coal gasification and chemical looping hydrogen generation (CLHG) for electric power production with CO2 capture. The CLHG-SOFC/GT plant is configurated and the schematic process is modeled using Aspen Plus® software. Syngas, produced by coal gasification, is converted to hydrogen with CO2 separation through a three-reactors CLHG process. Hydrogen is then fueled to SOFC for power generation. The unreacted hydrogen from SOFC burns in a combustor and drives gas turbine. The heat of the gas turbine exhaust stream is recovered in HRSG for steam bottoming cycle. At a system pressure of 20 bar and a cell temperature of 900 °C, the CLHG-SOFC/GT plant has a net power efficiency of 43.53% with no CO2 emissions. The hybrid power plant performance is attractive because of high energy conversion efficiency and zero-CO2-emission. Key parameters that influence the system performance are also discussed, including system operating pressure, cell temperature, fuel utilization factor, steam reactor temperature, CO2 expander exhaust pressure and inlet gas preheating.

Chen, Shiyi; Xue, Zhipeng; Wang, Dong; Xiang, Wenguo

2012-10-01

363

Evaluation test on a landfill gas-fired turbine at the Los Angeles County Sanitation District's Puente Hill Landfill Electric Generation Station. Air pollution test report  

SciTech Connect

A cooperative test program was conducted from February 25 through February 27, 1986 by Air Resources Board (ARB) and South Coast Air Quality Management District (SCAQMD) staff to evaluate the gaseous constituents from untreated landfill gas used to fuel a turbine and the emissions from that turbine located at the Los Angeles County Sanitation District's Puente Hills Electric Generating Station. The turbine was fueled with gases generated by the anaerobic decomposition of buried refuse at the Los Angeles County Sanitation District's Puente Hills Landfill. Emissions of criteria pollutant as determined from ARB test data are reported. Mass flow rates and destruction and removal efficiencies (DRE) of non-criteria pollutant compounds determined at the stack from SCQAMD bag-sample test data and mass-flow rates and DRE's for chlorinated and aromatic compounds determined from data from ARB resin samples are presented. Destruction and removal efficiencies based on mass-flow rates for chlorinated compounds ranged from 17 to 99+ percent and for aromatic compounds ranged from negative to 99+ percent. The possible formation of the compounds - chlorinated dioxins, furans, and polychlorinated biphenyls - was considered and samples were taken for analyses for these compounds. Dioxins, furans, and polychlorinated biphenyls were not detected in the inlet nor the outlet gas stream samples.

Not Available

1986-07-01

364

7 CFR 3201.107 - Water turbine bearing oils.  

Lubricants that are specifically formulated for use in the bearings found in water turbines for electric power generation. Previously designated turbine drip oils are used to lubricate bearings of shaft driven water well turbine pumps. (b) Minimum biobased...

2014-01-01

365

3rd Int'l Workshop on Micro & Nano Tech. for Power Generation & Energy Conv. (PowerMEMS'03), Makuhari, Japan, 4-5 Dec. 2003. PRELIMINARY DESIGN OF A MEMS STEAM TURBINE POWER PLANT-ON-A-CHIP  

E-print Network

3rd Int'l Workshop on Micro & Nano Tech. for Power Generation & Energy Conv. (PowerMEMS'03 turbine power plant-on-a-chip which implements the Rankine cycle for micro power generation. Keywords: MEMS, micro power generation, microturbine, micropump. INTRODUCTION The advent

Frechette, Luc G.

366

Calculating the Energy Cost of CO2 Removal in a Coal Based Gas Turbine Fuel Cell Hybrid Power Generation System with an Isolated Anode Stream  

SciTech Connect

In recent years there has been significant interest in identifying carbon capturing technologies that can be applied to fossil fuel power generation plants.CO2 capture technologies seek to reduce the amount of CO2 that would normally be emitted into the atmosphere from the daily operation of these plants. In terms of system efficiency and operating costs, this carbon capture is expensive. Further, the additional equipment that would be used to capture CO2 emissions greatly adds to the complexity of the system. There has also been significant interest in coal based gas turbine fuel cell hybrid power plants. A hybrid power plant can have much greater system efficiency than a normal gas turbine power plant because the heat that is normally unused in a standalone solid oxide fuel cell (SOFC) is recovered and used to drive a power producing turbine. It is thought that the increased system efficiency of the hybrid system might compensate for the increased expense of performing carbon capture. In order to provide some analytical insight on this tradeoff we present a 100 MW class coal fired gas turbine SOFC hybrid power generation system. The hybrid system operates at a pressure ratio of 6, and uses heat recuperation and cathode air recirculation to control the SOFC inlet temperature and the temperature change across the SOFC. A carbon capture scheme is added to this system in order to calculate the relative energy cost in terms of system efficiency due to CO2 ompression. The carbon capture is performed by burning the unused fuel from the SOFC in an isolated anode stream using pure O2 injection. The resulting heat that is generated from this process is then used to drive a secondary turbine that is placed in the anode exhaust stream where more work is extracted. With an isolated anode stream, the products of combustion from this secondary combustion process are mostly water and carbon dioxide. The water by-product is then condensed out of the stream leaving a relatively high concentration of CO2. This is then compressed, and removed from the system. In this study we present power plant efficiency calculations for the performance of the hybrid system with the carbon capturing loop. Our results show the effects on system performance that result from a changing fuel utilization factor.

Vanosdol, J.G.; Gemmen, R.S.; Liese, E.A.

2007-10-01

367

Wind turbine acoustics  

NASA Technical Reports Server (NTRS)

Available information on the physical characteristics of the noise generated by wind turbines is summarized, with example sound pressure time histories, narrow- and broadband frequency spectra, and noise radiation patterns. Reviewed are noise measurement standards, analysis technology, and a method of characterizing wind turbine noise. Prediction methods are given for both low-frequency rotational harmonics and broadband noise components. Also included are atmospheric propagation data showing the effects of distance and refraction by wind shear. Human perception thresholds, based on laboratory and field tests, are given. Building vibration analysis methods are summarized. The bibliography of this report lists technical publications on all aspects of wind turbine acoustics.

Hubbard, Harvey H.; Shepherd, Kevin P.

1990-01-01

368

Reply to Davies: Hydraulic fracturing remains a possible mechanism for  

E-print Network

LETTER Reply to Davies: Hydraulic fracturing remains a possible mechanism for observed methane mechanisms were leaky gas well casings and the possibility that hydraulic fracturing might generate new- knowledged the possibility of hydraulic fracturing playing a role. Is it possible that hydraulic fracturing

Jackson, Robert B.

369

Design of a hybrid battery charger system fed by a wind-turbine and photovoltaic power generators  

NASA Astrophysics Data System (ADS)

This paper is aimed to develop a digital signal processor (DSP) for controlling a solar cell and wind-turbine hybrid charging system. The DSP consists of solar cells, a wind turbine, a lead acid battery, and a buck-boost converter. The solar cells and wind turbine serve as the system's main power sources and the battery as an energy storage element. The output powers of solar cells and wind turbine have large fluctuations with the weather and climate conditions. These unstable powers can be adjusted by a buck-boost converter and thus the most suitable output powers can be obtained. This study designs a booster by using a dsPIC30F4011 digital signal controller as a core processor. The DSP is controlled by the perturbation and observation methods to obtain an effective energy circuit with a full 100 W charging system. Also, this DSP can, day and night, be easily controlled and charged by a simple program, which can change the state of the system to reach a flexible application based on the reading weather conditions.

Chang Chien, Jia-Ren; Tseng, Kuo-Ching; Yan, Bo-Yi

2011-03-01

370

Revenue Maximization of Electricity Generation for a Wind Turbine Integrated with a Compressed Air Energy Storage System  

E-print Network

controller is developed for a Compressed Air Energy Storage (CAES) system integrated with a wind turbine positive impact of energy storage on the U.S. economy. In [4], a methodology for profit analysis availability of wind energy more reliable, predictable and less disruptive to the electric grid. Moreover

Li, Perry Y.

371

Stresa, Italy, 26-28 April 2006 A SILICON-BASED MICRO GAS TURBINE ENGINE FOR POWER GENERATION  

E-print Network

of Manufacturing Technology, Singapore 658075 2 MEMS & Packaging Research Lab, AIST, Tsukuba, 305-8564 Japan 3 technology is proposed by MIT [1-3]. Tohoku University has also fabricated three-dimensional micro turbines using micro milling [4-5]. In micro heat engine system, both the heat loss and chamber wall cooling

Paris-Sud XI, Université de

372

Design of a hybrid battery charger system fed by a wind-turbine and photovoltaic power generators.  

PubMed

This paper is aimed to develop a digital signal processor (DSP) for controlling a solar cell and wind-turbine hybrid charging system. The DSP consists of solar cells, a wind turbine, a lead acid battery, and a buck-boost converter. The solar cells and wind turbine serve as the system's main power sources and the battery as an energy storage element. The output powers of solar cells and wind turbine have large fluctuations with the weather and climate conditions. These unstable powers can be adjusted by a buck-boost converter and thus the most suitable output powers can be obtained. This study designs a booster by using a dsPIC30F4011 digital signal controller as a core processor. The DSP is controlled by the perturbation and observation methods to obtain an effective energy circuit with a full 100 W charging system. Also, this DSP can, day and night, be easily controlled and charged by a simple program, which can change the state of the system to reach a flexible application based on the reading weather conditions. PMID:21456789

Chang Chien, Jia-Ren; Tseng, Kuo-Ching; Yan, Bo-Yi

2011-03-01

373

Wingtip vortex turbine  

NASA Technical Reports Server (NTRS)

A means for extracting rotational energy from the vortex created at aircraft wing tips which consists of a turbine with blades located in the crossflow of the vortex and attached downstream of the wingtip. The turbine has blades attached to a core. When the aircraft is in motion, rotation of a core transmits energy to a centrally attached shaft. The rotational energy thus generated may be put to use within the airfoil or aircraft fuselage.

Patterson, James C., Jr. (inventor)

1990-01-01

374

THERMAL HYDRAULICS KEYWORDS: thermal hydraulics,  

E-print Network

-fluid modeling of nuclear reactor systems. Thermal-hydraulic analysis codes such as RELAP5-3D ~Ref. 1! and FLICA regions of the system. In fact, the CFD code FLUENT has previously been coupled to RELAP5-3D ~Refs. 3

Smith, Barton L.

375

Electrokinetic high pressure hydraulic system  

DOEpatents

A compact high pressure hydraulic pump having no moving mechanical parts for converting electric potential to hydraulic force. The electrokinetic pump, which can generate hydraulic pressures greater than 2500 psi, can be employed to compress a fluid, either liquid or gas, and manipulate fluid flow. The pump is particularly useful for capillary-base systems. By combining the electrokinetic pump with a housing having chambers separated by a flexible member, fluid flow, including high pressure fluids, is controlled by the application of an electric potential, that can vary with time.

Paul, Phillip H. (Livermore, CA); Rakestraw, David J. (Fremont, CA)

2000-01-01

376

Mod-2 wind turbine system development. Volume 1: Executive summary  

NASA Technical Reports Server (NTRS)

The development of the MOD-2 wind turbine through acceptance testing and initial operational evaluation is documented. Pitch control hydraulic system, yaw control system, drive train, electrical power station, control system, operations and maintenance experience, and availability are discussed.

1982-01-01

377

Performance Analysis of a Wind Turbine Driven Swash Plate Pump for Large Scale Offshore Applications  

NASA Astrophysics Data System (ADS)

This paper deals with the performance modelling and analysis of offshore wind turbine-driven hydraulic pumps. The concept consists of an open loop hydraulic system with the rotor main shaft directly coupled to a swash plate pump to supply pressurised sea water. A mathematical model is derived to cater for the steady state behaviour of entire system. A simplified model for the pump is implemented together with different control scheme options for regulating the rotor shaft power. A new control scheme is investigated, based on the combined use of hydraulic pressure and pitch control. Using a steady-state analysis, the study shows how the adoption of alternative control schemes in a the wind turbine-hydraulic pump system may result in higher energy yields than those from a conventional system with an electrical generator and standard pitch control for power regulation. This is in particular the case with the new control scheme investigated in this study that is based on the combined use of pressure and rotor blade pitch control.

Buhagiar, D.; Sant, T.

2014-12-01

378

OTEC ammonia turbine design study  

Microsoft Academic Search

The design of an ammonia turbine generator for OTEC which uses high-performance state-of-the-art hardware is presented. Turbine aerodynamic performance was calculated using a modification of the Ainley and Mathieson (1951) pressure loss method to determine thermodynamic conditions at various locations within the turbine for a given geometry on the basis of mass flow continuity. It is found that the optimum

C. H. Kostors; S. P. Vincent

1979-01-01

379

Highly efficient electricity generation from biomass by integration and hybridization with combined cycle gas turbine (CCGT) plants for natural gas  

Microsoft Academic Search

Integration\\/co-firing with existing fossil fuel plants could give near term highly efficient and low cost power production from biomass. This paper presents a techno-economical analysis on options for integrating biomass thermal conversion (optimized for local resources ?50 MWth) with existing CCGT (combined cycle gas turbine) power plants (800–1400 MWth). Options include hybrid combined cycles (HCC), indirect gasification of biomass and simple cycle

Erik Pihl; Stefan Heyne; Henrik Thunman; Filip Johnsson

2010-01-01

380

A study on the flow characteristics of a direct drive turbine for energy conversion generation by experiment and CFD  

NASA Astrophysics Data System (ADS)

A variety of technologies has been proposed to capture the energy from waves. Some of the more promising designs are undergoing demonstration testing at commercial scales. Due to the complexity of most offshore wave energy devices and their motion response in different sea states, physical tank tests are common practice for WEC design. Full scale tests are also necessary, but are expensive and only considered once the design has been optimized. Computational Fluid Dynamics (CFD) is now recognized as an important complement to traditional physical testing techniques in offshore engineering. Once properly calibrated and validated to the problem, CFD offers a high density of test data and results in a reasonable timescale to assist with design changes and improvements to the device. The purpose of this study is to investigate the performance of a newly developed direct drive hydro turbine (DDT), which will be built in a caisson for extraction of wave energy. Experiments and CFD analysis are conducted to clarify the turbine performance and internal flow characteristics. The results show that commercial CFD code can be applied successfully to the simulation of the wave motion in the water tank. The performance of the turbine for wave energy converter is studied continuously for a ongoing project.

Cho, Y. J.; Zullah, M. A.; Faizal, M.; Choi, Y. D.; Lee, Y. H.

2012-11-01

381

Radial turbine cooling  

NASA Technical Reports Server (NTRS)

Radial turbines have been used extensively in many applications including small ground based electrical power generators, automotive engine turbochargers and aircraft auxiliary power units. In all of these applications the turbine inlet temperature is limited to a value commensurate with the material strength limitations and life requirements of uncooled metal rotors. To take advantage of all the benefits that higher temperatures offer, such as increased turbine specific power output or higher cycle thermal efficiency, requires improved high temperature materials and/or blade cooling. Extensive research is on-going to advance the material properties of high temperature superalloys as well as composite materials including ceramics. The use of ceramics with their high temperature potential and low cost is particularly appealing for radial turbines. However until these programs reach fruition the only way to make significant step increases beyond the present material temperature barriers is to cool the radial blading.

Roelke, Richard J.

1992-01-01

382

Application of simultaneous active and reactive power modulation of superconducting magnetic energy storage unit to damp turbine-generator subsynchronous oscillations  

SciTech Connect

An active and reactive power (P-Q) simultaneous control scheme which is based on a superconducting magnetic energy storage (SMES) unit is designed to damp out the subsynchronous resonant (SSR) oscillations of a turbine-generator unit. In order to suppress unstable torsional mode oscillations, a proportional-integral-derivative (PID) controller is employed to modulate the active and reactive power input/output of the SMES unit according to speed deviation of the generator shaft. The gains of the proposed PID controller are determined by pole assignment approach based on modal control theory. Eigenvalue analysis of the studied system shows that the PID controller is quite effective over a wide range of operating conditions. Dynamic simulations using the nonlinear system model are also performed to demonstrate the damping effect of the proposed control scheme under disturbance conditions.

Wu, Chijui; Lee, Yuangshung (National Taiwan Inst. of Tech., Taipie (Taiwan, Province of China))

1993-03-01

383

Study on safety operation for large hydroelectric generator unit  

NASA Astrophysics Data System (ADS)

Hydroelectric generator unit is a complex mechanical system which is composed of hydraulic turbine and electric generator. Rotary system is supported by the bearing bracket and the reinforced concrete structures, and vibration problem can't be avoided in the process of operating. Many large-scale hydroelectric units have been damaged because of the vibration problem in recent years. As the increase of the hydraulic turbine unit capacity and water head, the safe operation of hydraulic turbine has become a focus research in many countries. The operating characteristics of the hydraulic turbine have obvious differences at different working conditions. Based on the combination of field measurement and theoretical calculation, this paper shows a deep research on the safe operation of a large-scale Francis turbine unit. Firstly, the measurements of vibration, swing, pressure fluctuation and noise were carried out at 4 different heads. And also the relationships between vibrations and pressure fluctuations at different heads and working conditions were analysed deeply. Then the scientific prediction of safe operation for the unit at high head were done based on the CFD numerical calculation. Finally, this paper shows the division of the operating zone for the hydroelectric unit. According to the experimental results (vibrations, swings, pressure fluctuations and noise) as well as the theoretical results, the operating zone of the unit has been divided into three sections: prohibited operating zone, transition operating zone and safe operating zone. After this research was applied in the hydropower station, the security and economic efficiency of unit increased greatly, and enormous economic benefits and social benefits have been obtained.

Yan, Z. G.; Cui, T.; Zhou, L. J.; Zhi, F. L.; Wang, Z. W.

2012-11-01

384

Advanced wind turbine conceptual study  

NASA Astrophysics Data System (ADS)

Objective was to develop improvements to an existing wind turbine that would make wind energy more competitive in 1993-1995, and to initiate studies of an advanced wind turbine configuration that would make wind energy competitive for bulk electricity generation by 1998-2000. Objective has been achieved.

1995-07-01

385

Make Your Own Wind Turbine  

NSDL National Science Digital Library

In this activity, learners create a wind turbine model using a simple pattern, a thumbtack, and a pencil with an eraser. After constructing the model, learners blow on the wind turbine to simulate the wind. Use this activity to introduce alternative energy and electricity generation.

History, National M.

2012-06-26

386

MOD-2 wind turbine development  

NASA Technical Reports Server (NTRS)

The development of the Mod-2 turbine, designed to achieve a cost of electricity for the 100th production unit that will be competitive with conventional electric power generation is discussed. The Mod-2 wind turbine system (WTS) background, project flow, and a chronology of events and problem areas leading to Mod-2 acceptance are addressed. The role of the participating utility during site preparation, turbine erection and testing, remote operation, and routine operation and maintenance activity is reviewed. The technical areas discussed pertain to system performance, loads, and controls. Research and technical development of multimegawatt turbines is summarized.

Gordon, L. H.; Andrews, J. S.; Zimmerman, D. K.

1983-01-01

387

Alternative fuels for industrial gas turbines (AFTUR)  

Microsoft Academic Search

Environmentally friendly, gas turbine driven co-generation plants can be located close to energy consumption sites, which can produce their own fuel such as waste process gas or biomass derived fuels. Since gas turbines are available in a large power range, they are well suited for this application. Current gas turbine systems that are capable of burning such fuels are normally

Iskender Gökalp; Etienne Lebas

2004-01-01

388

Development of a more fish tolerant turbine runner advanced hydropower turbine project. Final report  

SciTech Connect

The Hidrostal pump is a single bladed combined screw/centrifugal pump which has been proven to transport fish with minimal injury. The focus of the ARL/NREC research project was to develop a new runner geometry which is effective in downstream fish passage and hydroelectric power generation. A flow of 1,000 cfs and a head in the range of 75 ft to 100 ft were selected for conceptual design of the new runner. Criteria relative to hydraulic characteristics which are favorable for fish passage were prepared based on a reassessment of the available information. Important criteria used to develop the new runner design included low pressure change rates, minimum absolute pressures, and minimum shear. Other criteria which are reflected in the runner design are a minimum number of blades (only two), minimum total length of leading edges, and large flow passages. Flow characteristics of the new runner were analyzed using two- dimensional and three-dimensional Computational Fluid Dynamic (CFD) models. The basic runner geometry was initially selected using the two-dimensional model. The three-dimensional model was used to investigate the flow characteristics in detail through the entire runner and to refine the design by eliminating potential problem areas at the leading and trailing edges. Results of the analyses indicated that the runner has characteristics which should provide safe fish passage with an overall power efficiency of approximately 90%. The size of the new runner, which is larger than conventional turbine runners with the same design flow and head, will provide engineering, fabrication, and installation.challenges related to the turbine components and the civil works. A small reduction in the overall efficiency would reduce the size of the runner considerably, would simplify the turbine manufacturing operations, and would allow installation of the new turbine at more hydroelectric sites.

Cook, T.C.; Hecker, G.E. [Worcester Polytechnic Inst., Holden, MA (United States). Alden Research Lab.; Faulkner, H.B.; Jansen, W. [Northern Research and Engineering Corp., Cambridge, MA (United States)

1997-01-01

389

Hydraulic fracturing-1  

SciTech Connect

This book contains papers on hydraulic fracturing. Topics covered include: An overview of recent advances in hydraulic fracturing technology; Containment of massive hydraulic fracture; and Fracturing with a high-strength proppant.

Not Available

1990-01-01

390

Candidate wind-turbine generator site cumulative meteorological data summary and data for January 1982 through September 1982  

SciTech Connect

Summarized cumulative hourly meteorological data for 20 new sites selected in early 1980 as part of the expanded candidate site program are presented. The reporting period is July 1980 through September 1982. The data collection program at some individual sites may not span this entire period, but will be contained within the reporting period. The purpose of providing the summarized data is to document the data collection program and to provide data that could be considered representative of longer-term meteorological conditions at each site. For each site, data are given in eight tables and in a topographic map showing the approximated location of the meteorological tower and turbine, if applicable. Use of the information from these tables, along with information about specific wind turbines, should allow the user to estimate the potential for longer-term average wind energy production at each site. Two appendices of other data are provided. Appendix A contains summarized data collected at new and original sites during the period January 1982 through September 1982. Appendix B contains cumulative summarized data for those original sites selected in 1976 with data collection programs continuing into 1982.

Sandusky, W.F.; Buck, J.W.; Renne, D.S.; Hadley, D.L.; Abbey, O.B.; Bradymire, S.L.; Gregory, J.L.

1983-08-01

391

7 CFR 1726.125 - Generating plant facilities.  

Code of Federal Regulations, 2010 CFR

...generating stations. Engineering services, steam generator...combustion turbine plants. Engineering services, prime mover and...Hydro installations. Engineering services, turbine/generator, civil works and powerhouse...

2010-01-01

392

7 CFR 1726.125 - Generating plant facilities.  

Code of Federal Regulations, 2011 CFR

...generating stations. Engineering services, steam generator...combustion turbine plants. Engineering services, prime mover and...Hydro installations. Engineering services, turbine/generator, civil works and powerhouse...

2011-01-01

393

Advanced wind turbine design studies: Advanced conceptual study  

Microsoft Academic Search

In conjunction with the US Department of Energy and the National Renewable Energy Laboratory's Advanced Wind Turbine Program, the Atlantic Orient Corporation developed preliminary designs for the next generation of wind turbines. These 50 kW and 350 kW turbines are based upon the concept of simplicity. By adhering to a design philosophy that emphasizes simplicity, we project that these turbines

P. Hughes; R. Sherwin

1994-01-01

394

Numerical Simulation of the Francis Turbine and CAD used to Optimized the Runner Design (2nd).  

NASA Astrophysics Data System (ADS)

Hydro Power is the most important renewable energy source on earth. The water is free of charge and with the generation of electric energy in a Hydroelectric Power station the production of green house gases (mainly CO2) is negligible. Hydro Power Generation Stations are long term installations and can be used for 50 years and more, care must be taken to guarantee a smooth and safe operation over the years. Maintenance is necessary and critical parts of the machines have to be replaced if necessary. Within modern engineering the numerical flow simulation plays an important role in order to optimize the hydraulic turbine in conjunction with connected components of the plant. Especially for rehabilitation and upgrading existing Power Plants important point of concern are to predict the power output of turbine, to achieve maximum hydraulic efficiency, to avoid or to minimize cavitations, to avoid or to minimized vibrations in whole range operation. Flow simulation can help to solve operational problems and to optimize the turbo machinery for hydro electric generating stations or their component through, intuitive optimization, mathematical optimization, parametric design, the reduction of cavitations through design, prediction of draft tube vortex, trouble shooting by using the simulation. The classic design through graphic-analytical method is cumbersome and can't give in evidence the positive or negative aspects of the designing options. So it was obvious to have imposed as necessity the classical design methods to an adequate design method using the CAD software. There are many option chose during design calculus in a specific step of designing may be verified in ensemble and detail form a point of view. The final graphic post processing would be realized only for the optimal solution, through a 3 D representation of the runner as a whole for the final approval geometric shape. In this article it was investigated the redesign of the hydraulic turbine's runner, medium head Francis type, with following value for the most important parameter, the rated specific speed ns.

Sutikno, Priyono

2010-06-01

395

Space Shuttle Upgrades Advanced Hydraulic Power System  

NASA Technical Reports Server (NTRS)

Three Auxiliary Power Units (APU) on the Space Shuttle Orbiter each provide 145 hp shaft power to a hydraulic pump which outputs 3000 psi hydraulic fluid to 41 hydraulic actuators. A hydrazine fuel powered APU utilized throughout the Shuttle program has undergone many improvements, but concerns remain with flight safety, operational cost, critical failure modes, and hydrazine related hazards. The advanced hydraulic power system (AHPS), also known as the electric APU, is being evaluated as an upgrade to replace the hydrazine APU. The AHPS replaces the high-speed turbine and hydrazine fuel supply system with a battery power supply and electric motor/pump that converts 300 volt electrical power to 3000 psi hydraulic power. AHPS upgrade benefits include elimination of toxic hydrazine propellant to improve flight safety, reduction in hazardous ground processing operations, and improved reliability. Development of this upgrade provides many interesting challenges and includes development of four hardware elements that comprise the AHPS system: Battery - The battery provides a high voltage supply of power using lithium ion cells. This is a large battery that must provide 28 kilowatt hours of energy over 99 minutes of operation at 300 volts with a peak power of 130 kilowatts for three seconds. High Voltage Power Distribution and Control (PD&C) - The PD&C distributes electric power from the battery to the EHDU. This 300 volt system includes wiring and components necessary to distribute power and provide fault current protection. Electro-Hydraulic Drive Unit (EHDU) - The EHDU converts electric input power to hydraulic output power. The EHDU must provide over 90 kilowatts of stable, output hydraulic power at 3000 psi with high efficiency and rapid response time. Cooling System - The cooling system provides thermal control of the Orbiter hydraulic fluid and EHDU electronic components. Symposium presentation will provide an overview of the AHPS upgrade, descriptions of the four hardware elements, and a summary of development results to date.

2004-01-01

396

Vertical axis wind turbines  

DOEpatents

A vertical axis wind turbine is described. The wind turbine can include a top ring, a middle ring and a lower ring, wherein a plurality of vertical airfoils are disposed between the rings. For example, three vertical airfoils can be attached between the upper ring and the middle ring. In addition, three more vertical airfoils can be attached between the lower ring and the middle ring. When wind contacts the vertically arranged airfoils the rings begin to spin. By connecting the rings to a center pole which spins an alternator, electricity can be generated from wind.

Krivcov, Vladimir (Miass, RU); Krivospitski, Vladimir (Miass, RU); Maksimov, Vasili (Miass, RU); Halstead, Richard (Rohnert Park, CA); Grahov, Jurij (Miass, RU)

2011-03-08

397

Micromachined hydraulic astable multivibrator  

Microsoft Academic Search

1 Abstract The paper presents a hydraulic astable multivibrator system. The system consists of hydraulic resistors, hydraulic capacitors and hydraulic pressure controlled valves. The system is designed, realised and tested. The measured system behaviour agrees well with the model simulations. The free running frequency of the multivibrator is 0.18 Hz and the output pressure swing is 90% of the supply

T. S. J. Lammerink; N. R. Tas; J. W. Berenschot; M. C. Elwenspoek; J. H. J. Fluitman

1995-01-01

398

Comprehensive experimental and numerical analysis of instability phenomena in pump turbines  

NASA Astrophysics Data System (ADS)

The changes in the electricity market have led to changed requirements for the operation of pump turbines. Utilities need to change fast and frequently between pumping and generating modes and increasingly want to operate at off-design conditions for extended periods. Operation of the units in instable areas of the machine characteristic is not acceptable and may lead to self-excited vibration of the hydraulic system. In turbine operation of pump turbines unstable behaviour can occur at low load off-design operation close to runaway conditions (S-shape of the turbine characteristic). This type of instability may impede the synchronization of the machine in turbine mode and thus increase start-up and switch over times. A pronounced S-shaped instability can also lead to significant drop of discharge in the event of load rejection. Low pressure on the suction side and in the tail-race tunnel could cause dangerous separation of the water column. Understanding the flow features that lead to the instable behaviour of pump turbines is a prerequisite to the design of machines that can fulfil the growing requirements relating to operational flexibility. Flow simulation in these instability zones is demanding due to the complex and highly unsteady flow patterns. Only unsteady simulation methods are able to reproduce the governing physical effects in these operating regions. ANDRITZ HYDRO has been investigating the stability behaviour of pump turbines in turbine operation in cooperation with several universities using simulation and measurements. In order to validate the results of flow simulation of unstable operating points, the Graz University of Technology (Austria) performed detailed experimental investigations. Within the scope of a long term research project, the operating characteristics of several pump turbine runners have been measured and flow patterns in the pump turbine at speed no load and runaway have been examined by 2D Laser particle image velocimetry (PIV). For several wicket gate positions, the flow fields in the vane-less space at runner inlet observed in the experiment are compared with the results of unsteady CFD flow simulations. Physical phenomena are visualized and insight to flow phenomena is given. Analyses using both results of simulation and measurement allow deriving a consistent explanation of the fluid mechanical mechanisms leading to the S-shaped instability of pump turbines.

Gentner, Ch; Sallaberger, M.; Widmer, Ch; Bobach, B.-J.; Jaberg, H.; Schiffer, J.; Senn, F.; Guggenberger, M.

2014-12-01

399

Advanced Hydropower Turbine Systems  

NSDL National Science Digital Library

The Idaho National Engineering and Environmental Laboratory manages this program, which explores and develops technology to improve current hydropower resources. Although hydroelectric generation systems produce far fewer harmful emissions than other options, they can have a detrimental effect to downstream water quality. Fish are very susceptible to injury or death from turbine systems. Several reports from the Advanced Hydropower Turbine Systems program, addressing these issues and documenting research into possible solutions, are available from this site. One of the most interesting projects of the program is the Sensor Fish. This device is used "to characterize physical conditions fish experience during passage through hydro turbines, spill stilling basins, high-discharge outfalls, and other dam passage routes."

2002-01-01

400

Wind Turbine Acoustics  

NASA Technical Reports Server (NTRS)

Wind turbine generators, ranging in size from a few kilowatts to several megawatts, are producing electricity both singly and in wind power stations that encompass hundreds of machines. Many installations are in uninhabited areas far from established residences, and therefore there are no apparent environmental impacts in terms of noise. There is, however, the potential for situations in which the radiated noise can be heard by residents of adjacent neighborhoods, particularly those neighborhoods with low ambient noise levels. A widely publicized incident of this nature occurred with the operation of the experimental Mod-1 2-MW wind turbine, which is described in detail elsewhere. Pioneering studies which were conducted at the Mod-1 site on the causes and remedies of noise from wind turbines form the foundation of much of the technology described in this chapter.

Hubbard, Harvey H.; Shepherd, Kevin P.

2009-01-01

401

Highly efficient electricity generation through a hybrid molten carbonate fuel cell-closed loop gas turbine plant  

Microsoft Academic Search

Fuel cells have been revealed to be very attractive power generation systems, promising highly efficient electricity generation and very low environmental impact. With the high-temperature fuel cells still in embryonic infancy, the very high energetic efficiency can be further increased by their integration into hybrid cycles. While a wide variety of potential bottoming technologies for the exploitation of the high

Piero Lunghi; Stefano Ubertini; Umberto Desideri

2001-01-01

402

Heat transfer and flow on the first-stage blade tip of a power generation gas turbine: Part 1 -- Experimental results  

SciTech Connect

A combined experimental and computational study has been performed to investigate the detailed distribution of convective heat transfer coefficients on the first-stage blade tip surface for a geometry typical of large power generation turbines (> 100 MW). This paper is concerned with the design and execution of the experimental portion of the study, which represents the first reported investigation to obtain nearly full surface information on heat transfer coefficients within an environment that develops an appropriate pressure distribution about an airfoil blade tip and shroud model. A stationary blade cascade experiment has been run consisting of three airfoils, the center airfoil having a variable tip gap clearance. The airfoil models the aerodynamic tip section of a high-pressure turbine blade with inlet Mach number of 0.30, exit Mach number of 0.75, pressure ratio of 1.45, exit Reynolds number based on axial chord of 2.57 x 10{sup 6}, and total turning of about 110 degrees. A hue detection based liquid crystal method is used to obtain the detailed heat transfer coefficient distribution on the blade tip surface for flat, smooth tip surfaces with both sharp and rounded edges. The cascade inlet turbulence intensity level took on values of either 5 or 9%. The cascade also models the casing recess in the shroud surface ahead of the blade. Experimental results are shown for the pressure distribution measurements on the airfoil near the tip gap, on the blade tip surface, and on the opposite shroud surface. Tip surface heat transfer coefficient distributions are shown for sharp edge and rounded edge tip geometries at each of the inlet turbulence intensity levels.

Bunker, R.S.; Bailey, J.C.; Ameri, A.A.

2000-04-01

403

TBC experience in land based gas turbines  

NASA Technical Reports Server (NTRS)

This paper summarizes prior and on-going machine evaluations of TBC coatings for power generation applications. Rainbow testing of TBC's on turbine nozzles, shrouds, and buckets are described along with a test on combustor liners. GEPG has conducted over 15 machine tests with TBC coated turbine nozzles of various coatings. TBC performance has been quite good and additional testing, including TBC's on shrouds and buckets, is continuing. Included is a brief comparison of TBC requirements for power generation and aircraft turbines.

Nelson, Warren A.; Orenstein, Robert M.

1995-01-01

404

Evaluation of advanced turbomachinery for underground pumped hydroelectric storage. Part 3. Multistage unregulated pump/turbines for operating heads of 1000 to 1500 m  

SciTech Connect

This is the final report in a series of three on studies of advanced hydraulic turbomachinery for underground pumped hydroelectric storage. All three reports address Francis-type, reversible pump/turbines. The first report covered single-stage regulated units; the second report covered two-stage regulated units; the present report covers multistage unregulated units. Multistage unregulated pump/turbines offer an economically attractive option for heads of 1000 to 1500 m. The feasibility of developing such machines for capacities up to 500 MW and operating heads up to 1500 m has been evaluated. Preliminary designs have been generated for six multistage pump/turbines. The designs are for nominal capacities of 350 and 500 MW and for operating heads of 1000, 1250, and 1500 m. Mechanical, hydraulic, and economic analyses indicate that these machines will behave according to the criteria used to design them and that they can be built at a reasonable cost with no unsolvable problems. Efficiencies of 85.8% and 88.5% in the generating and pumping modes, respectively, can be expected for the 500-MW, 1500-m unit. Performances of the other five machines are at least comparable, and usually better. Over a 1000 to 1500-m head range, specific $/kW costs of the pump/turbines in mid-1978 US dollars vary from 19.0 to 23.1 for the 500-MW machines, and from 21.0 to 24.1 for the 350-MW machines.

Frigo, A.A.; Pistner, C.

1980-08-01

405

Electokinetic high pressure hydraulic system  

DOEpatents

A compact high pressure hydraulic system having no moving parts for converting electric potential to hydraulic force and for manipulating fluids. Electro-osmotic flow is used to provide a valve and means to compress a fluid or gas in a capillary-based system. By electro-osmotically moving an electrolyte between a first position opening communication between a fluid inlet and outlet and a second position closing communication between the fluid inlet and outlet the system can be configured as a valve. The system can also be used to generate forces as large as 2500 psi that can be used to compress a fluid, either a liquid or a gas.

Paul, Phillip H. (Livermore, CA); Rakestraw, David J. (Fremont, CA)

2000-01-01

406

12. DETAIL VIEW OF GENERATOR BAY, GENERATOR ROOM, SHOWING TURBINEGENERATOR ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

12. DETAIL VIEW OF GENERATOR BAY, GENERATOR ROOM, SHOWING TURBINE-GENERATOR DRIVE SHAFT IN FOREGROUND, ACCESS BULKHEAD TO TURBINE IN BACKGROUND - Nine Mile Hydroelectric Development, Powerhouse, State Highway 291 along Spokane River, Nine Mile Falls, Spokane County, WA

407

Optimization of cycloidal water turbine and the performance improvement by individual blade control  

Microsoft Academic Search

This paper investigates an advanced vertical axis turbine to enhance power generation from water energy. The turbine, known as a cycloidal water turbine, is a straight-bladed type adopting a cycloidal blade system that actively controls the rotor blades for improved turbine efficiency, according to the operating conditions. These characteristics enable the turbine to self-start and produce high electric power at

In Seong Hwang; Yun Han Lee; Seung Jo Kim

2009-01-01

408

Use of an Autonomous Sensor to Evaluate the Biological Performance of the Advanced Turbine at Wanapum Dam  

SciTech Connect

Hydropower is the largest renewable energy resource in the world and the United States. However, Hydropower dams have adverse ecological impacts because migrating fish may be injured or killed when they pass through hydro turbines. In the Columbia and Snake River basins, dam operators and engineers are required to make these hydroelectric facilities more fish-friendly through changes in hydro-turbine design and operation after fish population declines and the subsequent listing of several species of Pacific salmon in the Endangered Species Act of 1973. Grant County Public Utility District (Grant PUD) requested authorization from the Federal Energy Regulatory Commission to replace the 10 turbines at Wanapum Dam with advanced hydropower turbines that are designed to improve survival for fish passing through the turbines while improving operation efficiency and increasing power generation. The U.S. Department of Energy Office of Energy Efficiency and Renewable Energy provided co-funding to Grant PUD for aspects of performance testing that supported the application. As an additional measure to the primary evaluation measure of direct injury and mortality rates of juvenile Chinook salmon using balloon tag-recapture methodology, this study used an autonomous sensor device to provide insight into the specific hydraulic conditions or physical stresses that the fish experienced or the specific causes of the biological response. We found that the new blade shape and the corresponding reduction of turbulence in the advanced hydropower turbine were effective. The frequency of severe events based on Sensor Fish pressure and acceleration measurements showed trends similar to those of fish survival determined by balloon tag-recapture tests. In addition, the new turbine provided a better pressure and rate of change environment for fish passage. Overall, the Sensor Fish data indicated that the advanced hydro turbine design met the desired fish passage goals for Wanapum Dam.

Deng, Zhiqun; Carlson, Thomas J.; Duncan, Joanne P.; Richmond, Marshall C.; Dauble, Dennis D.

2010-10-13

409

Chapter 14: Wind Turbine Control Systems  

SciTech Connect

Wind turbines are complex, nonlinear, dynamic systems forced by gravity, stochastic wind disturbances, and gravitational, centrifugal, and gyroscopic loads. The aerodynamic behavior of wind turbines is nonlinear, unsteady, and complex. Turbine rotors are subjected to a complicated three-dimensional turbulent wind inflow field that drives fatigue loading. Wind turbine modeling is also complex and challenging. Accurate models must contain many degrees of freedom (DOF) to capture the most important dynamic effects. The rotation of the rotor adds complexity to the dynamics modeling. Designs of control algorithms for wind turbines must account for these complexities. Algorithms must capture the most important turbine dynamics without being too complex and unwieldy. Off-the-shelf commercial soft ware is seldom adequate for wind turbine dynamics modeling. Instead, specialized dynamic simulation codes are usually required to model all the important nonlinear effects. As illustrated in Figure 14-1, a wind turbine control system consists of sensors, actuators and a system that ties these elements together. A hardware or software system processes input signals from the sensors and generates output signals for actuators. The main goal of the controller is to modify the operating states of the turbine to maintain safe turbine operation, maximize power, mitigate damaging fatigue loads, and detect fault conditions. A supervisory control system starts and stops the machine, yaws the turbine when there is a significant yaw misalignment, detects fault conditions, and performs emergency shut-downs. Other parts of the controller are intended to maximize power and reduce loads during normal turbine operation.

Wright, A. D.

2009-01-01

410

ADVANCED TURBINE SYSTEMS PROGRAM  

SciTech Connect

Natural gas combustion turbines are rapidly becoming the primary technology of choice for generating electricity. At least half of the new generating capacity added in the US over the next twenty years will be combustion turbine systems. The Department of Energy has cosponsored with Siemens Westinghouse, a program to maintain the technology lead in gas turbine systems. The very ambitious eight year program was designed to demonstrate a highly efficient and commercially acceptable power plant, with the ability to fire a wide range of fuels. The main goal of the Advanced Turbine Systems (ATS) Program was to develop ultra-high efficiency, environmentally superior and cost effective competitive gas turbine systems for base load application in utility, independent power producer and industrial markets. Performance targets were focused on natural gas as a fuel and included: System efficiency that exceeds 60% (lower heating value basis); Less than 10 ppmv NO{sub x} emissions without the use of post combustion controls; Busbar electricity that are less than 10% of state of the art systems; Reliability-Availability-Maintainability (RAM) equivalent to current systems; Water consumption minimized to levels consistent with cost and efficiency goals; and Commercial systems by the year 2000. In a parallel effort, the program was to focus on adapting the ATS engine to coal-derived or biomass fuels. In Phase 1 of the ATS Program, preliminary investigators on different gas turbine cycles demonstrated that net plant LHV based efficiency greater than 60% was achievable. In Phase 2 the more promising cycles were evaluated in greater detail and the closed-loop steam-cooled combined cycle was selected for development because it offered the best solution with least risk for achieving the ATS Program goals for plant efficiency, emissions, cost of electricity and RAM. Phase 2 also involved conceptual ATS engine and plant design and technology developments in aerodynamics, sealing, combustion, cooling, materials, coatings and casting development. The market potential for the ATS gas turbine in the 2000-2014 timeframe was assessed for combined cycle, simple cycle and integrated gasification combined cycle, for three engine sizes. The total ATS market potential was forecasted to exceed 93 GW. Phase 3 and Phase 3 Extension involved further technology development, component testing and W501ATS engine detail design. The technology development efforts consisted of ultra low NO{sub x} combustion, catalytic combustion, sealing, heat transfer, advanced coating systems, advanced alloys, single crystal casting development and determining the effect of steam on turbine alloys. Included in this phase was full-load testing of the W501G engine at the McIntosh No. 5 site in Lakeland, Florida.

Gregory Gaul

2004-04-21

411

Performance and Internal Flow Characteristics of a Cross-Flow Hydro Turbine by the Shapes of Nozzle and Runner Blade  

Microsoft Academic Search

Recently, small hydropower attracts attention because of its clean, renewable and abundant energy resources to develop. Therefore, a cross-flow hydraulic turbine is proposed for small hydropower in this study because the turbine has relatively simple structure and high possibility of applying to small hydropower. The purpose of this study is to investigate the effect of the turbine's structural configuration on

Young-Do Choi; Jae-Ik Lim; You-Taek Kim; Young-Ho Lee

2008-01-01

412

Initialization of wind turbine models in power system dynamics simulations  

Microsoft Academic Search

As a result of increasing environmental concern, increasing amounts of electricity are generated from renewable sources. One way of generating electricity from renewable sources is to use wind turbines. A tendency to erect more wind turbines can be observed. As a result of this, in the near future wind turbines may start to influence the behavior of electrical power systems.

J. G. Slootweg; H. Polinder; W. L. Kling

2001-01-01

413

Effect of vortex generators on the power conversion performance and structural dynamic loads of the Mod-2 wind turbine  

NASA Technical Reports Server (NTRS)

Applying vortex generators from 20 to 100 percent span of the Mod-2 rotor resulted in a projected increase in annual energy capture of 20 percent and reduced the wind speed at which rated power is reached by nearly 3 m/sec. Application of vortex generators from 20 to 70 percent span, the fixed portion of the Mod-2 rotor, resulted in a projected increase in annual energy capture of about half this. This improved performance came at the cost of a small increase in cyclic blade loads in below rated power conditions. Cyclic blade loads were found to correlate well with the change in wind speed during one rotor revolution.

Sullivan, T. L.

1984-01-01

414

Numerical simulation of turbulence flow in a Kaplan turbine -Evaluation on turbine performance prediction accuracy-  

NASA Astrophysics Data System (ADS)

The understanding and accurate prediction of the flow behaviour related to cavitation and pressure fluctuation in a Kaplan turbine are important to the design work enhancing the turbine performance including the elongation of the operation life span and the improvement of turbine efficiency. In this paper, high accuracy turbine and cavitation performance prediction method based on entire flow passage for a Kaplan turbine is presented and evaluated. Two-phase flow field is predicted by solving Reynolds-Averaged Navier-Stokes equations expressed by volume of fluid method tracking the free surface and combined with Reynolds Stress model. The growth and collapse of cavitation bubbles are modelled by the modified Rayleigh-Plesset equation. The prediction accuracy is evaluated by comparing with the model test results of Ns 400 Kaplan model turbine. As a result that the experimentally measured data including turbine efficiency, cavitation performance, and pressure fluctuation are accurately predicted. Furthermore, the cavitation occurrence on the runner blade surface and the influence to the hydraulic loss of the flow passage are discussed. Evaluated prediction method for the turbine flow and performance is introduced to facilitate the future design and research works on Kaplan type turbine.

Ko, P.; Kurosawa, S.

2014-12-01

415

Wind turbine  

DOEpatents

A wind turbine of the type having an airfoil blade (15) mounted on a flexible beam (20) and a pitch governor (55) which selectively, torsionally twists the flexible beam in response to wind turbine speed thereby setting blade pitch, is provided with a limiter (85) which restricts unwanted pitch change at operating speeds due to torsional creep of the flexible beam. The limiter allows twisting of the beam by the governor under excessive wind velocity conditions to orient the blades in stall pitch positions, thereby preventing overspeed operation of the turbine. In the preferred embodiment, the pitch governor comprises a pendulum (65,70) which responds to changing rotor speed by pivotal movement, the limiter comprising a resilient member (90) which engages an end of the pendulum to restrict further movement thereof, and in turn restrict beam creep and unwanted blade pitch misadjustment.

Cheney, Jr., Marvin C. (Glastonbury, CT)

1982-01-01

416

Airborne Wind Turbine  

SciTech Connect

Broad Funding Opportunity Announcement Project: Makani Power is developing an Airborne Wind Turbine (AWT) that eliminates 90% of the mass of a conventional wind turbine and accesses a stronger, more consistent wind at altitudes of near 1,000 feet. At these altitudes, 85% of the country can offer viable wind resources compared to only 15% accessible with current technology. Additionally, the Makani Power wing can be economically deployed in deep offshore waters, opening up a resource which is 4 times greater than the entire U.S. electrical generation capacity. Makani Power has demonstrated the core technology, including autonomous launch, land, and power generation with an 8 meter wingspan, 20 kW prototype. At commercial scale, Makani Power aims to develop a 600 kW, 28 meter wingspan product capable of delivering energy at an unsubsidized cost competitive with coal, the current benchmark for low-cost power.

None

2010-09-01

417

Large, horizontal-axis wind turbines  

NASA Technical Reports Server (NTRS)

Development of the technology for safe, reliable, environmentally acceptable large wind turbines that have the potential to generate a significant amount of electricity at costs competitive with conventional electric generating systems are presented. In addition, these large wind turbines must be fully compatible with electric utility operations and interface requirements. There are several ongoing large wind system development projects and applied research efforts directed toward meeting the technology requirements for utility applications. Detailed information on these projects is provided. The Mod-O research facility and current applied research effort in aerodynamics, structural dynamics and aeroelasticity, composite and hybrid composite materials, and multiple system interaction are described. A chronology of component research and technology development for large, horizontal axis wind turbines is presented. Wind characteristics, wind turbine economics, and the impact of wind turbines on the environment are reported. The need for continued wind turbine research and technology development is explored. Over 40 references are sited and a bibliography is included.

Linscott, B. S.; Perkins, P.; Dennett, J. T.

1984-01-01

418

Build a Wind Turbine  

NSDL National Science Digital Library

This hands-on project provides step-by-step instructions for building a vertical axis wind turbine in secondary classrooms. The 17-page construction plans may be freely downloaded and are organized for first-time builders. Comprehensive background information on wind energy and renewable energy are provided. Registered teacher-users also have access to supporting lesson plans. All of the materials are readily available in hardware or grocery stores. This resource, which meets multiple national science standards, was developed to spark students' interest in learning more about renewable energy sources and the science and engineering principles that underlie the harnessing of renewable power. Editor's Note: Wind turbines work by using an internal generator to convert the mechanical energy of the spinning turbine shaft into electricity. This particular project is modeled after the Savonius rotor system, which uses uses drag -- not lift -- to capture energy for making electricity. Although it isn't as efficient as a conventional horizontal axis turbine, it is much easier to build.

2007-10-25

419

Effect of unbalanced magnetic pull and hydraulic seal force on the vibration of large rotor-bearing systems  

NASA Astrophysics Data System (ADS)

The influence of unbalanced magnetic pull (UMP) and hydraulic seal force on the vibration of large rotor-bearing systems is studied. The UMP caused by rotor eccentricity imposes important effects on rotating machinery, especially for large generators such as water turbine generator sets, because these machines operate above their first critical speed in some instances and are supported by oil film bearings. A magnetic stiffness matrix for studying the effects of the UMP is proposed. The magnetic stiffness matrix can be generated by decomposing the expression of air gap magnetic field energy. Two vibration models are constructed using the Lagrange equation. The difference between the two models lies in the boundary support condition: one has rigid support and the other has elastic bearing support. The influence of the magnetic stiffness and elastic support on the critical speed of the rotor is studied using Lyapunov nonlinear vibration stability theory. The vibration amplitude of the rotor is calculated, taking the magnetic stiffness and horizontal centrifugal force into account. The unbalanced hydraulic seal force is produced because of the asymmetry of seal clearance. This imbalance is one of the factors that causes self-excited vibration in rotating machinery, and is as important as the UMP for large water turbine generator sets. The rotor-bearing system is supported by an oil film journal bearing, whose characteristic also impose considerable influence on vibration. On the basis of the above-mentioned conditions, a three-dimensional finite element model of the rotating system that includes the oil film journal bearing is constructed. The effect of the UMP and unbalanced hydraulic seal force is considered in the construction, and studied in relation to the magnetic parameters, seal parameters, journal bearing stiffness, and outer diameter of the rotating machine critical speed. Conclusions may benefit the dynamic design and optimized operation of large rotating machinery.

Song, Z.; Guo, P.; Liu, Y.

2014-12-01

420

Lightning protection system for a wind turbine  

DOEpatents

In a wind turbine (104, 500, 704) having a plurality of blades (132, 404, 516, 744) and a blade rotor hub (120, 712), a lightning protection system (100, 504, 700) for conducting lightning strikes to any one of the blades and the region surrounding the blade hub along a path around the blade hub and critical components of the wind turbine, such as the generator (112, 716), gearbox (708) and main turbine bearings (176, 724).

Costin, Daniel P. (Chelsea, VT); Petter, Jeffrey K. (Williston, VT)

2008-05-27

421

Hydraulics calculations for hydraulic Stirling engines  

SciTech Connect

The role of hydraulic devices and processes in Stirling engine design is discussed. Simple and conveniently organized algorithms are presented for the calculation of hydraulic system losses and for optimization of clearance seals. Fluid makeup system losses are discussed. The fluid inertia tube is compared with the free hydraulic piston. Scaling of power piston flow loss with engine design power level is such that flow loss inefficiencies tend to be large for engine power levels above a few hundred watts unless specific measures are taken to minimize the piston flow loss. A method for eliminating the power piston flow loss in large engines is discussed.

Riggle, P.; Emigh, S.G.; Lo, N.S.C.; Noble, J.E.; Olan, R.W.; White, M.A.

1984-08-01

422

SMART POWER TURBINE  

SciTech Connect

Gas turbines are the choice technology for high-performance power generation and are employed in both simple and combined cycle configurations around the world. The Smart Power Turbine (SPT) program has developed new technologies that are needed to further extend the performance and economic attractiveness of gas turbines for power generation. Today's power generation gas turbines control firing temperatures indirectly, by measuring the exhaust gas temperature and then mathematically calculating the peak combustor temperatures. But temperatures in the turbine hot gas path vary a great deal, making it difficult to control firing temperatures precisely enough to achieve optimal performance. Similarly, there is no current way to assess deterioration of turbine hot-gas-path components without shutting down the turbine. Consequently, maintenance and component replacements are often scheduled according to conservative design practices based on historical fleet-averaged data. Since fuel heating values vary with the prevalent natural gas fuel, the inability to measure heating value directly, with sufficient accuracy and timeliness, can lead to maintenance and operational decisions that are less than optimal. GE Global Research Center, under this Smart Power Turbine program, has developed a suite of novel sensors that would measure combustor flame temperature, online fuel lower heating value (LHV), and hot-gas-path component life directly. The feasibility of using the ratio of the integrated intensities of portions of the OH emission band to determine the specific average temperature of a premixed methane or natural-gas-fueled combustion flame was demonstrated. The temperature determined is the temperature of the plasma included in the field of view of the sensor. Two sensor types were investigated: the first used a low-resolution fiber optic spectrometer; the second was a SiC dual photodiode chip. Both methods worked. Sensitivity to flame temperature changes was remarkably high, that is a 1-2.5% change in ratio for an 11.1 C (20 F) change in temperature at flame temperatures between 1482.2 C (2700 F) and 1760 C (3200 F). Sensor ratio calibration was performed using flame temperatures determined by calculations using the amount of unburned oxygen in the exhaust and by the fuel/air ratio of the combustible gas mixture. The agreement between the results of these two methods was excellent. The sensor methods characterized are simple and viable. Experiments are underway to validate the GE Flame Temperature Sensor as a practical tool for use with multiburner gas turbine combustors. The lower heating value (LHV) Fuel Quality Sensor consists of a catalytic film deposited on the surface of a microhotplate. This micromachined design has low heat capacity and thermal conductivity, making it ideal for heating catalysts placed on its surface. Several methods of catalyst deposition were investigated, including micropen deposition and other proprietary methods, which permit precise and repeatable placement of the materials. The use of catalysts on the LHV sensor expands the limits of flammability (LoF) of combustion fuels as compared with conventional flames; an unoptimized LoF of 1-32% for natural gas (NG) in air was demonstrated with the microcombustor, whereas conventionally 4 to 16% is observed. The primary goal of this work was to measure the LHV of NG fuels. The secondary goal was to determine the relative quantities of the various components of NG mixes. This determination was made successfully by using an array of different catalysts operating at different temperatures. The combustion parameters for methane were shown to be dependent on whether Pt or Pd catalysts were used. In this project, significant effort was expended on making the LHV platform more robust by the addition of high-temperature stable materials, such as tantalum, and the use of passivation overcoats to protect the resistive heater/sensor materials from degradation in the combustion environment. Modeling and simulation were used to predict improved sensor designs.

Nirm V. Nirmalan

2003-11-01

423

Wind turbine dynamics  

NASA Technical Reports Server (NTRS)

Recent progress in the analysis and prediction of the dynamic behavior of wind turbine generators is discussed. The following areas were addressed: (1) the adequacy of state of the art analysis tools for designing the next generation of wind power systems; (2) the use of state of the art analysis tools designers; and (3) verifications of theory which might be lacking or inadequate. Summaries of these informative discussions as well as the questions and answers which followed each paper are documented in the proceedings.

Thresher, R. W. (editor)

1981-01-01

424

Hydraulic design of a re-circulating water cooling system of a combined cycle power plant in Thailand  

SciTech Connect

The paper describes the hydraulic design and hydraulic transient analysis of the re-circulating water cooling system of the combined cyclo Sipco power cogeneration plant in Thailand. The power plant of 450 MW total capacity is proposed to be built in two stages. Stage one will produce 300 MW of power and will consist of two gas turbine generators (GTG) and one steam turbine generator (STG). Stage two will produce 150 MW of power and will consist of one GTG and one STG. The cooling system will consist of one GTG and one STG. The cooling system will consist of cooling towers, a combined collecting basin and pump intake sump, pumps and motors, and separate conveyance systems and condensers for the generator units in the two stages. In a re-circulating water cooling system, cold water is pumped from the pump intake sump to the condensers through the conveyance system and hot water from the condensers is carried through the returning pipeline system to the cooling towers, whence the water after cooling is drained into the sump at the base of the towers. Total cooling water requirement for the system in stage one is estimated to be 112,000 gallons per minute (GPM), and that in stage two, 56,000 GPM. The sump is designed using the computer program HEC-2, developed by the US Army Corps of Engineers (COE) and the pump intake basin, following the recommendations of the Hydraulic Institute. The pumps were sized by computing the head loss in the system, and, the steady state and transient performances (during pump start-up and shut-down procedures and due to possible power or mechanical failure of one or all pumps) of the system were analyzed by mathematically modeling the system using the computer program WHAMO (Water Hammer nd Mass Oscillations), also developed by the COE.

Sarkar, C.K.; Pandit, D.R. [Parsons Infrastructure and Technology Group, Boston, MA (United States); Kwon, S.G. [Kolon Engineering and Construction Co., Ltd., Seoul (Korea, Republic of)

1998-12-31

425

Design and construction of an impulse turbine  

NASA Astrophysics Data System (ADS)

Impulse turbine has been constructed to be used in the program of Hydraulic Machines, Faculty of Mechanical Engineering at the Universidad Pontificia Bolivariana, sede Bucaramanga. For construction of the impulse turbine (Pelton) detailed plans were drawn up taking into account the design and implementation of the fundamental equations of hydraulic turbomachinery. From the experimental data found maximum mechanical efficiency of 0.6 ± 0.03 for a water flow of 2.1 l/s. The maximum overall efficiency was 0.23 ± 0.02 for a water flow of 0.83 l/s. The design parameter used was a power of 1 kW, as flow regulator built a needle type regulator, which performed well, the model of the bucket or vane is built on a machine type CNC (Computer Numerical Control). For the construction of the impeller and blades was used aluminium because of chemical and physical characteristics and the casing was manufactured in acrylic.

Hernández, E.

2013-11-01

426

Development of Advanced Seals for Industrial Turbine Applications  

NASA Astrophysics Data System (ADS)

A critical area being addressed to improve industrial turbine performance is reducing the parasitic leakage flows through the various static and dynamic seals. Implementation of advanced seals into General Electric (GE) industrial turbines has progressed well over the last few years with significant operating performance gains achieved. Advanced static seals have been placed in gas turbine hot gas-path junctions and steam turbine packing ring segment end gaps. Brush seals have significantly decreased labyrinth seal leakages in gas turbine compressors and turbine interstages, steam turbine interstage and end packings, industrial compressor shaft seals, and generator seals. Abradable seals are being developed for blade-tip locations in various turbine locations. This presentation summarizes the status of advanced seal development for industrial turbines at GE.

Chupp, Raymond E.; Aksit, Mahmut F.; Ghasripoor, Farshad; Turnquist, Norman A.; Dinc, Saim; Mortzheim, Jason; Demiroglu, Mehmet

2002-10-01

427

Energy 101: Wind Turbines - 2014 Update  

ScienceCinema

See how wind turbines generate clean electricity from the power of wind. The video highlights the basic principles at work in wind turbines, and illustrates how the various components work to capture and convert wind energy to electricity. This updated version also includes information on the Energy Department's efforts to advance offshore wind power. Offshore wind energy footage courtesy of Vestas.

None

2014-06-05

428

Wind tower augmentation of wind turbines  

Microsoft Academic Search

The operating principle of the 'Baud-Geers' wind towers traditionally used in Iran for ventilation and passive cooling of architectural structures is presently adapted to house a vertical axis wind turbine. Unlike annular diffuser-augmented, horizontal axis wind turbines, the 'wind tower' does not have to be trained into the wind and generates less noise. It may also be either free standing

M. N. Bahadori

1984-01-01

429

Energy 101: Wind Turbines - 2014 Update  

SciTech Connect

See how wind turbines generate clean electricity from the power of wind. The video highlights the basic principles at work in wind turbines, and illustrates how the various components work to capture and convert wind energy to electricity. This updated version also includes information on the Energy Department's efforts to advance offshore wind power. Offshore wind energy footage courtesy of Vestas.

None

2014-05-06

430

Effects of Combustor Exit Profiles on Vane Aerodynamic Loading and Heat Transfer in a High Pressure Turbine  

Microsoft Academic Search

The flow and thermal fields exiting gas turbine combustors dictate the overall perfor- mance of the downstream turbine. The goal of this work was to investigate the effects of engine representative combustor exit profiles on high pressure turbine vane aerodynamics and heat transfer. The various profiles were produced using a nonreacting turbine inlet profile generator in the Turbine Research Facility

M. D. Barringer; K. A. Thole; M. D. Polanka

2009-01-01

431

Utilization of coal mine ventilation exhaust as combustion air in gas-fired turbines for electric and/or mechanical power generation. Semi-annual topical report, June 1995--August 1995  

SciTech Connect

Methane emitted during underground coal mining operations is a hazard that is dealt with by diluting the methane with fresh air and exhausting the contaminated air to the atmosphere. Unfortunately this waste stream may contain more than 60% of the methane resource from the coal, and in the atmosphere the methane acts as a greenhouse gas with an effect about 24.5 times greater than CO{sub 2}. Though the waste stream is too dilute for normal recovery processes, it can be used as combustion air for a turbine-generator, thereby reducing the turbine fuel requirements while reducing emissions. Preliminary analysis indicates that such a system, built using standard equipment, is economically and environmentally attractive, and has potential for worldwide application.

NONE

1995-12-01

432

Trailing Edge Noise Model Applied to Wind Turbine Airfoils  

E-print Network

Trailing Edge Noise Model Applied to Wind Turbine Airfoils Franck Bertagnolio Risø-R-1633(EN) Risø Bertagnolio Title: Trailing Edge Noise Model Applied to Wind Turbine Airfoils Department: Wind Energy generation that are relevant to wind turbine technology with focus on trailing edge noise. Secondly, the so

433

Study of the nozzle flow in a cross-flow turbine  

Microsoft Academic Search

An investigation of the flow inside the nozzle of a Cross-Flow turbine, which is a hydraulic turbine where the rectangular water jet issuing from the nozzle crosses the rotor blades twice, is presented here. Part of the investigation consisted in the experimental measurement of the static pressure distribution on the inside walls of two different nozzle configurations, both with the

N. H. Costa Pereira; J. E. Borges

1996-01-01

434

Biphase Turbine Tests on Process Fluids  

E-print Network

are commonly utilized in many industrial processes. Examples include production of oil and gas, refrigeration separation of hydrocarbons, pulp and paper process ing, natural gas cleanup solvent regeneration, boiler blowdown,.and methanol production. When a... the entropy increase, a portion of the inlet enthalpy is con verted into kinetic energy in the form of a high velocity two-phase jet. Conventional single-phase hydraulic or vapor turbines are not practical for energy recovery from such liquid dominated...

Helgeson, N. L.; Maddox, J. P.

1983-01-01

435

Single Rotor Turbine  

DOEpatents

A rotor for use in turbine applications has a centrifugal compressor having axially disposed spaced apart fins forming passages and an axial turbine having hollow turbine blades interleaved with the fins and through which fluid from the centrifugal compressor flows.

Platts, David A. (Los Alamos, NM)

2004-10-26

436

Advanced wind turbine design studies: Advanced conceptual study. Final report  

Microsoft Academic Search

In conjunction with the US Department of Energy and the National Renewable Energy Laboratory`s Advanced Wind Turbine Program, the Atlantic Orient Corporation developed preliminary designs for the next generation of wind turbines. These 50 kW and 350 kW turbines are based upon the concept of simplicity. By adhering to a design philosophy that emphasizes simplicity, we project that these turbines

P. Hughes; R. Sherwin

1994-01-01

437

Transient CFD simulation of a Francis turbine startup  

NASA Astrophysics Data System (ADS)

To assess the life expectancy of hydraulic turbines, it is essential to obtain the loading on the blades, especially during transient operations known to be the most damaging. This paper presents a simplified CFD setup to model the startup phase of a Francis turbine while it goes from rest to speed no-load condition. The fluid domain included one distributor sector coupled with one runner passage. The guide vane motion and change in the angular velocity were included in a commercial code with user functions. Comparisons between numerical results and measurements acquired on a full-size turbine showed that most of the flow physics occurring during startup were captured.

Nicolle, J.; Morissette, J. F.; Giroux, A. M.

2012-11-01

438

Thermally Actuated Hydraulic Pumps  

NASA Technical Reports Server (NTRS)

Thermally actuated hydraulic pumps have been proposed for diverse applications in which direct electrical or mechanical actuation is undesirable and the relative slowness of thermal actuation can be tolerated. The proposed pumps would not contain any sliding (wearing) parts in their compressors and, hence, could have long operational lifetimes. The basic principle of a pump according to the proposal is to utilize the thermal expansion and contraction of a wax or other phase-change material in contact with a hydraulic fluid in a rigid chamber. Heating the chamber and its contents from below to above the melting temperature of the phase-change material would cause the material to expand significantly, thus causing a substantial increase in hydraulic pressure and/or a substantial displacement of hydraulic fluid out of the chamber. Similarly, cooling the chamber and its contents from above to below the melting temperature of the phase-change material would cause the material to contract significantly, thus causing a substantial decrease in hydraulic pressure and/or a substantial displacement of hydraulic fluid into the chamber. The displacement of the hydraulic fluid could be used to drive a piston. The figure illustrates a simple example of a hydraulic jack driven by a thermally actuated hydraulic pump. The pump chamber would be a cylinder containing encapsulated wax pellets and containing radial fins to facilitate transfer of heat to and from the wax. The plastic encapsulation would serve as an oil/wax barrier and the remaining interior space could be filled with hydraulic oil. A filter would retain the encapsulated wax particles in the pump chamber while allowing the hydraulic oil to flow into and out of the chamber. In one important class of potential applications, thermally actuated hydraulic pumps, exploiting vertical ocean temperature gradients for heating and cooling as needed, would be used to vary hydraulic pressures to control buoyancy in undersea research vessels. Heretofore, electrically actuated hydraulic pumps have been used for this purpose. By eliminating the demand for electrical energy for pumping, the use of the thermally actuated hydraulic pumps could prolong the intervals between battery charges, thus making it possible to greatly increase the durations of undersea exploratory missions.

Jones, Jack; Ross, Ronald; Chao, Yi

2008-01-01

439

Quantifying mortal injury of juvenile Chinook salmon exposed to simulated hydro-turbine passage  

SciTech Connect

A proportion of juvenile Chinook salmon and other salmonids travel through one or more turbines during seaward migration in the Columbia and Snake River every year. Despite this understanding, limited information exists on how these fish respond to hydraulic pressures found during turbine passage events. In this study we exposed juvenile Chinook salmon to varied acclimation pressures and subsequent exposure pressures (nadir) to mimic the hydraulic pressures of large Kaplan turbines (ratio of pressure change). Additionally, we varied abiotic (total dissolved gas, rate of pressure change) and biotic (condition factor, fish length, fish weight) factors that may contribute to the incidence of mortal injury associated with fish passing through hydro-turbines. We determined that the main factor associated with mortal injury of juvenile Chinook salmon during simulated turbine passage was the ratio between acclimation and nadir pressures. Condition factor, total dissolved gas, and the rate of pressure change were found to only slightly increase the predictive power of equations relating probability of mortal injury to conditions of exposure or characteristics of test fish during simulated turbine passage. This research will assist engineers and fisheries managers in operating and improving hydroelectric facility efficiency while minimizing mortality and injury of turbine-passed juvenile Chinook salmon. The results are discussed in the context of turbine development and the necessity of understanding how different species of fish will respond to the hydraulic pressures of turbine passage.

Brown, Richard S.; Carlson, Thomas J.; Gingerich, Andrew J.; Stephenson, John R.; Pflugrath, Brett D.; Welch, Abigail E.; Langeslay, Mike; Ahmann, Martin L.; Johnson, Robert L.; Skalski, John R.; Seaburg, Adam; Townsend, Richard L.

2012-02-01

440

Tornado type wind turbines  

SciTech Connect

A tornado type wind turbine has a vertically disposed wind collecting tower with spaced apart inner and outer walls and a central bore. The upper end of the tower is open while the lower end of the structure is in communication with a wind intake chamber. An opening in the wind chamber is positioned over a turbine which is in driving communication with an electrical generator. An opening between the inner and outer walls at the lower end of the tower permits radially flowing air to enter the space between the inner and outer walls while a vertically disposed opening in the wind collecting tower permits tangentially flowing air to enter the central bore. A porous portion of the inner wall permits the radially flowing air to interact with the tangentially flowing air so as to create an intensified vortex flow which exits out of the top opening of the tower so as to create a low pressure core and thus draw air through the opening of the wind intake chamber so as to drive the turbine.

Hsu, Ch.-T.

1984-06-05

441

Marine Hydrokinetic Turbine Power-Take-Off Design for Optimal Performance and Low Impact on Cost-of-Energy: Preprint  

SciTech Connect

Marine hydrokinetic devices are becoming a popular method for generating marine renewable energy worldwide. These devices generate electricity by converting the kinetic energy of moving water, wave motion or currents, into electrical energy through the use of a Power-Take-Off (PTO) system. Most PTO systems incorporate a mechanical or hydraulic drive train, power generator and electric control/conditioning system to deliver the generated electric power to the grid at the required state. Like wind turbine applications, the PTO system must be designed for high reliability, good efficiency, and long service life with reasonable maintenance requirements, low cost and an appropriate mechanical design for anticipated applied steady and unsteady loads. The ultimate goal of a PTO design is high efficiency, low maintenance and cost with a low impact on the device Cost-of-Energy (CoE).

Beam, M.; Kline, B.; Elbing, B.; Straka, W.; Fontaine, A.; Lawson, M.; Li, Y.; Thresher, R.; Previsic, M.

2012-04-01

442

Marine Hydrokinetic Turbine Power-Take-Off Design for Optimal Performance and Low Impact on Cost-of-Energy: Preprint  

SciTech Connect

Marine hydrokinetic devices are becoming a popular method for generating marine renewable energy worldwide. These devices generate electricity by converting the kinetic energy of moving water, wave motion or currents, into electrical energy through the use of a power-take-off (PTO) system. Most PTO systems incorporate a mechanical or hydraulic drivetrain, power generator, and electric control/conditioning system to deliver the generated electric power to the grid at the required state. Like wind turbine applications, the PTO system must be designed for high reliability, good efficiency, and long service life with reasonable maintenance requirements, low cost, and an appropriate mechanical design for anticipated applied steady and unsteady loads. The ultimate goal of a PTO design is high efficiency and low maintenance and cost, with a low impact on the device cost-of-energy (CoE).

Beam, M.; Kline, B.; Elbing, B.; Straka, W.; Fontaine, A.; Lawson, M.; Li, Y.; Thresher, R.; Previsic, M.

2013-02-01

443

Leaf Hydraulics Lawren Sack1  

E-print Network

Leaf Hydraulics Lawren Sack1 and N. Michele Holbrook2 1 Department of Botany, University of Hawai influence rates of transpiration and photosynthesis. Leaf hydraulic conductance (Kleaf) varies more than 65. #12;Contents INTRODUCTION. . . . . . . . . . . . . . . . . 362 LEAF HYDRAULIC CONDUCTANCE

Sack, Lawren

444

Suspensions in hydraulic fracturing  

Microsoft Academic Search

Suspensions or slurries are widely used in well stimulation and hydraulic fracturing processes to enhance the production of oil and gas from the underground hydrocarbon-bearing formation. The success of these processes depends significantly upon having a thorough understanding of the behavior of suspensions used. Therefore, the characterization of suspensions under realistic conditions, for their rheological and hydraulic properties, is very

Shah

1996-01-01

445

Gas Turbine Blade Tip Heat Transfer and Cooling: A Literature Survey  

Microsoft Academic Search

Gas turbines are widely used for aircraft propulsion, land-base power generation, and other industrial applications like trains, marines, automobiles, etc. To satisfy the fast development of advanced gas turbines, the operating temperature must be increased to improve the thermal efficiency and output work of the gas turbine engine. However, the heat transferred to the turbine blade is substantially increased as

Bengt Sunden; Gongnan Xie

2010-01-01

446

On optimization of sensor selection for aircraft gas turbine engines Ramgopal Mushini  

E-print Network

for generating an optimal sensor set [3]. 3. Aircraft gas turbine engines An aircraft gas turbine engineOn optimization of sensor selection for aircraft gas turbine engines Ramgopal Mushini Cleveland sets for the problem of aircraft gas turbine engine health parameter estimation. The performance metric

Simon, Dan

447

Loss mechanisms in turbine tip clearance flows  

E-print Network

Numerical simulations of tip clearance ow have been carried out to dene the loss generation mechanisms associated with tip leakage in unshrouded axial turbines. Mix- ing loss between the leakage, which takes the form of a ...

Huang, Arthur (Arthur C.)

2011-01-01

448

Passively cooled direct drive wind turbine  

DOEpatents

A wind turbine is provided that passively cools an electrical generator. The wind turbine includes a plurality of fins arranged peripherally around a generator house. Each of the fins being oriented at an angle greater than zero degrees to allow parallel flow of air over the fin. The fin is further tapered to allow a constant portion of the fin to extend beyond the air stream boundary layer. Turbulence initiators on the nose cone further enhance heat transfer at the fins.

Costin, Daniel P. (Chelsea, VT)

2008-03-18

449

Electrical Cost Reduction Via Steam Turbine Cogeneration  

E-print Network

mechanical energy. Conversion from mechanical energy to electrical is performed by the generator which typically operates at 94 to 96 percent efficiency. In some systems there are also speed reduction gear losses of about 2 percent, but backpressure... turbines with induction generators are usually directly driven without a reduction gear. A complete energy balance for a steam turbine cogeneration system must also account for other system losses, particularly those in the boiler. Boiler losses occur...

Ewing, T. S.; Di Tullio, L. B.

450

Practical solutions to turbine control system retrofit problems  

SciTech Connect

This paper addresses the use of microprocessors in retrofitting turbine control systems. The topics of the paper include modern control system architecture, human machine interface, steam flow linearization and automatic valve calibration, retrofit hydraulic interfacing, reliability considerations, and advanced valve positioning technique (quarter cycle damping).

Cavanagh, M. [GEC Alsthom Engineering Systems, Whetstone (United Kingdom); Lovejoy, K. [Lovejoy Controls Corp., Waukesha, WI (United States)

1996-10-01

451

21. VIEW EAST OF GENERATOR IN SOUTH END OF GRANITEVILLE ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

21. VIEW EAST OF GENERATOR IN SOUTH END OF GRANITEVILLE MILL BASEMENT. A LEFFEL HYDRAULIC VERTICAL SHAFT TYPE F TURBINE CAPABLE OF PRODUCING 615HP AT 327RPM WITH 40 FEET OF HEAD PRESSURE SITS BELOW THE GENERATOR SHOWN AT LEFT CENTER OF THE PHOTOGRAPH. THIS IS COUPLED TO THE WESTINGHOUSE THREE-PHASE, 60 CYCLE ALTERNATING CURRENT GENERATOR IN THE PHOTO. THE GENERATOR DELIVERED 583 KVA AT 600 VOLTS. IT WAS RATED AT 640 AMPHERES. EXCITATION POWER WAS PROVIDED BY A SMALLER GENERATOR MOUNTED VERTICALLY ON TOP OF THE SHAFT COMMON TO BOTH GENERATORS. THE EXCITER, AT TOP LEFT CENTER, PROVIDED 125 VOLTS AT 60 AMPERES. CONTROL PANEL IS AT THE RIGHT OF THE PHOTO. THIS SYSTEM RAN UNTIL THE EARLY 1990s. - Graniteville Mill, Marshall Street, Graniteville, Aiken County, SC

452

Dynamic behaviour of pump-turbine runner: From disk to prototype runner  

NASA Astrophysics Data System (ADS)

In recent decades, in order to increase output power of hydroelectric turbomachinery, the design head and the flow rate of the hydraulic turbines have been increased greatly. This has led to serious vibratory problems. The pump-turbines have to work at various operation conditions to satisfy the requirements of the power grid. However, larger hydraulic forces will result in high vibration levels on the turbines, especially, when the machines operate at off-design conditions. Due to the economic considerations, the pump-turbines are built as light as possible, which will change the dynamic response of the structures. According to industrial cases, the fatigue damage of the pump-turbine runner induced by hydraulic dynamic forces usually happens on the outer edge of the crown, which is near the leading edges of blades. To better understand the reasons for this kind of fatigue, it is extremely important to investigate the dynamic response behaviour of the hydraulic turbine, especially the runner, by experimental measurement and numerical simulation. The pump-turbine runner has a similar dynamic response behaviour of the circular disk. Therefore, in this paper the dynamic response analyses for circular disks with different dimensions and disk-blades-disk structures were carried out to better understand the fundamental dynamic behaviour for the complex turbomachinery. The influences of the pattern and number of blades were discussed in detail.

Huang, X. X.; Egusquiza, E.; Valero, C.; Presas, A.

2013-12-01

453

PowerJet Wind Turbine Project  

SciTech Connect

PROJECT OBJECTIVE The PowerJet wind turbine overcomes problems characteristic of the small wind turbines that are on the market today by providing reliable output at a wide range of wind speeds, durability, silent operation at all wind speeds, and bird-safe operation. Prime Energy�s objective for this project was to design and integrate a generator with an electrical controller and mechanical controls to maximize the generation of electricity by its wind turbine. The scope of this project was to design, construct and test a mechanical back plate to control rotational speed in high winds, and an electronic controller to maximize power output and to assist the base plate in controlling rotational speed in high winds. The test model will continue to operate beyond the time frame of the project, with the ultimate goal of manufacturing and marketing the PowerJet worldwide. Increased Understanding of Electronic & Mechanical Controls Integrated With Electricity Generator The PowerJet back plate begins to open as wind speed exceeds 13.5 mps. The pressure inside the turbine and the turbine rotational speed are held constant. Once the back plate has fully opened at approximately 29 mps, the controller begins pulsing back to the generator to limit the rotational speed of the turbine. At a wind speed in excess of 29 mps, the controller shorts the generator and brings the turbine to a complete stop. As the wind speed subsides, the controller releases the turbine and it resumes producing electricity. Data collection and instrumentation problems prevented identification of the exact speeds at which these events occur. However, the turbine, controller and generator survived winds in excess of 36 mps, confirming that the two over-speed controls accomplished their purpose. Technical Effectiveness & Economic Feasibility Maximum Electrical Output The output of electricity is maximized by the integration of an electronic controller and mechanical over-speed controls designed and tested during the course of this project. The output exceeds that of the PowerJet�s 3-bladed counterparts (see Appendix). Durability All components of the PowerJet turbine assembly�including the electronic and mechanical controls designed, manufactured and field tested during the course of this project�proved to be durable through severe weather conditions, with constant operation and no interruption in energy production. Low Cost Materials for the turbine, generator, tower, charge controllers and ancillary parts are available at reasonable prices. Fabrication of these parts is also readily available worldwide. The cost of assembling and installing the turbine is reduced because it has fewer parts and requires less labor to manufacture and assemble, making it competitively priced compared with turbines of similar output manufactured in the U.S. and Europe. The electronic controller is the unique part to be included in the turbine package. The controllers can be manufactured in reasonably-sized production runs to keep the cost below $250 each. The data logger and 24 sensors are for research only and will be unnecessary for the commercial product. Benefit To Public The PowerJet wind-electric system is designed for distributed wind generation in 3 and 4 class winds. This wind turbine meets DOE�s requirements for a quiet, durable, bird-safe turbine that eventually can be deployed as a grid-connected generator in urban and suburban settings. Results As described more fully below and illustrated in the Appendices, the goals and objectives outlined in 2060 SOPO were fully met. Electronic and mechanical controls were successfully designed, manufactured and integrated with the generator. The turbine, tower, controllers and generators operated without incident throughout the test period, surviving severe winter and summer weather conditions such as extreme temperatures, ice and sustained high winds. The electronic controls were contained in weather-proof electrical boxes and the elec

Bartlett, Raymond J

2008-11-30

454

Efficiency Mapping for a Linear Hydraulic-Actuator  

E-print Network

Efficiency Mapping for a Linear Hydraulic-Actuator Noah D. Manring Mechanical and Aerospace at generating an efficiency map for a linear hydraulic-actuator that is controlled using an open-centered 4- way valve. Using the basic configuration of a double rod, double- acting linear actuator, equations

Manring, Noah D.

455

Foundations for offshore wind turbines.  

PubMed

An important engineering challenge of today, and a vital one for the future, is to develop and harvest alternative sources of energy. This is a firm priority in the UK, with the government setting a target of 10% of electricity from renewable sources by 2010. A component central to this commitment will be to harvest electrical power from the vast energy reserves offshore, through wind turbines or current or wave power generators. The most mature of these technologies is that of wind, as much technology transfer can be gained from onshore experience. Onshore wind farms, although supplying 'green energy', tend to provoke some objections on aesthetic grounds. These objections can be countered by locating the turbines offshore, where it will also be possible to install larger capacity turbines, thus maximizing the potential of each wind farm location. This paper explores some civil-engineering problems encountered for offshore wind turbines. A critical component is the connection of the structure to the ground, and in particular how the load applied to the structure is transferred safely to the surrounding soil. We review previous work on the design of offshore foundations, and then present some simple design calculations for sizing foundations and structures appropriate to the wind-turbine problem. We examine the deficiencies in the current design approaches, and the research currently under way to overcome these deficiencies. Designs must be improved so that these alternative energy sources can compete economically with traditional energy suppliers. PMID:14667305

Byrne, B W; Houlsby, G T