Simulation of water column separation in Francis pump-turbine draft tube

International Nuclear Information System (INIS)

Nicolet, C; Alligne, S; Bergant, A; Avellan, F

2012-01-01

The paper presents the modelling, simulation and analysis of the transient behaviour of a 340 MW pump-turbine in case of emergency shutdown in turbine mode with focus on possible draft tube water column separation. The model of a pumped storage power plant with simplified layout is presented. This model includes a penstock feeding one 340MW pump-turbine with the related rotating inertia and a tailrace tunnel. The model of the tailrace tunnel allowing for water column separation simulation is introduced. The simulation results of the transient behaviour of the pump-turbine in case of emergency shutdown in generating mode, with and without downstream water column separation model are presented for different degree of severity triggered by the submergence and the tailrace tunnel length. The amplitudes of the pressure peaks induced by the cavity collapse are analysed with respect to the pressure drop magnitude and tailrace dimensions. The maximum and minimum pressure amplitudes obtained along the tailrace tunnel are analysed for different test case conditions.

Pump-turbines with constant flow direction; Pumpenturbinen mit gleicher Durchstroemrichtung

Energy Technology Data Exchange (ETDEWEB)

Mollenkopf, G. [Zentrale Forschung Engineering, KSB AG, Frankenthal (Germany)

1997-12-31

This research project was sponsored by the federal ministry of science and technology BMFT (product owner: New Materials and Chemical Technologies - NMT). Its aim was to develop a novel unit that can work both as a pump and a turbine with a constant flow direction through internal blade adjustment. This specifically high-speed pump-turbine is suited for plants where a liquid in one case needs to be hauled against a rising pressure and where, in another case, there is a pressure drop in the same direction. So far, either a separate pump and turbine each are used which are temporarily stopped, involving corresponding effort, or - almost as a rule - the turbine is dispensed with, so that the energy locked up in the pressure drop goes unused. (orig.) [Deutsch] Die Zielsetzung unseres Forschungsvorhabens, das vom BMFT (Produkttraeger: Neue Materialien und Chemische Technologien - NMT) gefoerdert wird, war die Entwicklung eines neuartigen Aggregats, das durch interne Schaufelverstellung in der Lage ist, sowohl als Pumpe als auch als Turbine mit gleichbleibender Durchstroemrichtung zu arbeiten. Diese spezifisch schnellaeufige Pumpturbine kommt fuer Anlagen in Frage, in denen eine Fluessigkeit im einen Fall gegen einen anstehenden Druck gefoerdert werden muss und im anderen Fall in gleicher Richtung ein Druckgefaelle zur Verfuegung steht. Entweder werden bisher getrennt aufgestellte Pumpen und Turbinen mit zeitweisem Stillstand und entsprechendem Aufwand eingesetzt oder es wird - fast in der Regel - auf die Turbine und damit auf die im Druckgefaelle enthaltene Energie verzichtet. (orig.)

Experimental investigation of the turbine instability of a pump-turbine during synchronization

International Nuclear Information System (INIS)

Guggenberger, M; Senn, F; Schiffer, J; Jaberg, H; Gentner, C; Sallaberger, M; Widmer, C

2014-01-01

Although the technology of pump-turbines is generally well known the operation is still affected by flow phenomena that are quite complex and not fully understood. One of these phenomena is the S-shape instability which occurs in turbine mode at low load operation, close to runaway conditions. The instability results in an S-shape of the turbine characteristics and complicates the synchronization of the machine. Numerical investigations performed in the past indicated that the occurrence of turbine instabilities is connected with the appearance of rotor-stator interactions, and backflow regions in the vane less space between guide vane and impeller. This paper presents the results and conclusions of experimental investigations of pump-turbine instabilities carried out to find a practical explanation for the flow phenomena responsible for the appearance of the S-shaped characteristics. In the scope of a joint research project with Andritz Hydro, the Institute for Hydraulic Fluidmachinery at Graz University of Technology optimized an existing 4-quadrant test rig for an experimental investigation at off design conditions featuring the possibility for adjusting stable operation of instabilities. All the experimental investigations were based on IEC60193-standard using a pump turbine model provided by Andritz Hydro AG. In addition to the standard measurements of flow rate, head and efficiency the interaction between model and its hydraulic environment were analysed by dynamic pressure sensors. Additional pressure sensors integrated in the guide vane apparatus were used to investigate pressure distributions in the model. Particle Image Velocimetry (PIV) allowed the measurement of the velocity field in the vane less space between impeller and guide vanes and in the environment of two single guide vanes. The experimental investigations were focused on operation points in the S-shape region of the characteristics. For each operation point 190 double images for 20 rotor

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

International Nuclear Information System (INIS)

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

2014-01-01

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 Q 11 and M 11 in different moving directions of the dynamic trajectories give different n 11 . 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 Q 11 and M 11 in different moving directions of the dynamic trajectories

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

Science.gov (United States)

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

2014-03-01

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.

Dynamic modeling and dynamical analysis of pump-turbines in S-shaped regions during runaway operation

International Nuclear Information System (INIS)

Zhang, Hao; Chen, Diyi; Wu, Changzhi; Wang, Xiangyu; Lee, Jae-Myung; Jung, Kwang-Hyo

2017-01-01

Highlights: • Novel dynamic model of a pump-turbine in S-shaped regions is proposed. • A stability criterion of runaway point is given. • Global dynamic characteristics of the pump-turbine are investigated. • Effects of the slopes of the characteristic curve on the stability are studied. - Abstract: There is a region of pump-turbine operation, often called the S-shaped region, in which one unit rotational speed corresponds to three unit flows or torques. In this paper, the dynamic model of the pump-turbine in S-shaped regions is established by introducing the nonlinear piecewise function of relative parameters. Then, the global bifurcation diagrams of the pump-turbine are presented to analyze its dynamic characteristics in the S-shaped regions. Meanwhile, a stability criterion of runaway point is given based on the established theoretical model. The numerical experiments are conducted on the model and the results are in good agreement with the theoretical analysis. Furthermore, the effects of the characteristic curve slopes on the stability of the pump-turbine are studied by an innovative use of the three-dimensional bifurcation diagrams. Finally, the factors influencing the runaway stability of pump-turbines are also discussed, based on the dynamic analysis.

Groundwater heat pumps with turbines for the return water; Grundwasser-Waermepumpe mit Rueckgabe-Turbinierung

Energy Technology Data Exchange (ETDEWEB)

Eberhard, M.

2007-09-15

This final report for the Swiss Federal Office of Energy (SFOE) reports on improvements in the efficiency of a ground water heat pump installation in an office building. The water return well was equipped with a turbine. In this installation, the ground water is pumped up from a depth of 45 meters which means that a lot of electricity is needed for the pumping of the water. Coefficients of performance of the system are quoted for the situation with and without the turbine. The conversion of a pump for use as a turbine is commented on. The construction of a specially developed turbine with reduced electricity consumption is suggested. Seasonal performance data of the system is provided in tabular form.

The aerodynamic performance of the water pumping wind turbine for Bangladesh

International Nuclear Information System (INIS)

Ahmed, S.; Islam, M.Q.

2004-01-01

In order to examine the feasibility of wind energy for water pumping in Bangladesh, an experimental investigation of performance characteristics of horizontal axis wind turbines has been conducted. Wind characteristics of various regions of Bangladesh have been analysed and hence a compatible design of horizontal axis wind turbine applicable to the pump has been suggested. The wind data collected by the meteorological department of Bangladesh for a period 16 years of 20 stations at different heights between 5m and 10m have been converted to 20m hub-height using power law. From these data monthly average speeds have been calculated. It is observed that for few regions of Bangladesh, there is reasonable wind speed available throughout the year to extract useful power. Considering a particular prospective region of Bangladesh a wind turbine has been designed for water pumping. The design incorporates the generalized procedure for determination of rotor and pump sizes. Thus it can be also used for any other region as well. In this paper, a generalized design for Bangladesh, a nomogram and an empirical relation have been developed for the rotor and the pump size for a particular region of Bangladesh.(author)

AWWA E102-17 submersible vertical turbine pumps

CERN Document Server

2017-01-01

This standard describes minimum requirements for submersible vertical turbine pumps utilizing a discharge column pipe assembly, 5 hp or larger, used in water service, including materials, design, manufacture, inspection, and testing.

What we learn from surveillance testing of standby turbine driven and motor driven pumps

International Nuclear Information System (INIS)

Christie, B.

1996-01-01

This paper describes a comparison of the performance information collected by the author and the respective system engineers from five standby turbine driven pumps at four commercial nuclear electric generating units in the United States and from two standby motor driven pumps at two of these generating units. Information was collected from surveillance testing and from Non-Test actuations. Most of the performance information (97%) came from surveillance testing. open-quotes Conditional Probabilitiesclose quotes of the pumps ability to respond to a random demand were calculated for each of the seven standby pumps and compared to the historical record of the Non-Test actuations. It appears that the Conditional Probabilities are comparable to the rate of success for Non-Test actuations. The Conditional Probabilities of the standby motor driven pumps (approximately 99%) are better than the Conditional Probabilities of the standby turbine driven pumps (82%-96% range). Recommendations were made to improve the Conditional Probabilities of the standby turbine driven pumps

What we learn from surveillance testing of standby turbine driven and motor driven pumps

Energy Technology Data Exchange (ETDEWEB)

Christie, B.

1996-12-01

This paper describes a comparison of the performance information collected by the author and the respective system engineers from five standby turbine driven pumps at four commercial nuclear electric generating units in the United States and from two standby motor driven pumps at two of these generating units. Information was collected from surveillance testing and from Non-Test actuations. Most of the performance information (97%) came from surveillance testing. {open_quotes}Conditional Probabilities{close_quotes} of the pumps ability to respond to a random demand were calculated for each of the seven standby pumps and compared to the historical record of the Non-Test actuations. It appears that the Conditional Probabilities are comparable to the rate of success for Non-Test actuations. The Conditional Probabilities of the standby motor driven pumps (approximately 99%) are better than the Conditional Probabilities of the standby turbine driven pumps (82%-96% range). Recommendations were made to improve the Conditional Probabilities of the standby turbine driven pumps.

FOREWORD: 6th International Conference on Pumps and Fans with Compressors and Wind Turbines (ICPF2013)

Science.gov (United States)

Wu, Yulin; Wang, Zhengwei; Yuan, Shouqi; Shi, Weidong; Liu, Shuhong; Luo, Xingqi; Wang, Fujun

2013-12-01

; other fluid machinery and devices, such as, wind turbines, turbochargers and reversible pump-turbines, clearance and sealing, jets, filters and mixers; and their engineering application and their system behavior, especially, the application of the renewable energy of pumps, compressors, fans and blowers. The objective of the conference was to provide an opportunity for researchers, engineers and students to report on the latest developments in the fields of pumps, compressors, fans and turbochargers, as well as systems. The participants were encouraged to present their work in progress with a short lead time, and the conference promoted discussion of the problems encountered. The ICPF2013 brought together 191 scientists and researchers from 14 countries, affiliated with universities, technology centers and industrial firms to debate topics related to advanced technologies for pumps and fans, which would enhance the sustainable development of fluid machinery and fluid engineering. The Scientific Committee selected 166 technical papers on the following topics: (i) Principles of Fluid Machinery, (ii) Pumps, (iii) Compressors, Fans and Turbochargers, (iv) Turbines, (v) Cavitation and Multiphase Flow, (vi) Systems and Other Fluid Machinery, and 10 invited plenary and invited session lectures, which were presented at the conference, to be included in the proceedings. All the papers of ICPF2013, which were published in this volume of IOP Conference Series: Materials Science and Engineering, have been peer reviewed through processes administered by the editors of the ICPF2013, those are Yulin Wu, Zhengwei Wang, Shouqi Yuan, Weidong Shi, Shuhong Liu, Xingqi Luo and Fujun Wang. We sincerely hope that the 6th International Conference on Pumps and Fans with Compressors and Wind Turbines is a significant step forward in the worldwide efforts to address the present challenges facing modern fluid machines. Professor Yulin Wu Chairman of the Local Organizing Committee 6th International

Analysis of the pump-turbine S characteristics using the detached eddy simulation method

Science.gov (United States)

Sun, Hui; Xiao, Ruofu; Wang, Fujun; Xiao, Yexiang; Liu, Weichao

2015-01-01

Current research on pump-turbine units is focused on the unstable operation at off-design conditions, with the characteristic curves in generating mode being S-shaped. Unlike in the traditional water turbines, pump-turbine operation along the S-shaped curve can lead to difficulties during load rejection with unusual increases in the water pressure, which leads to machine vibrations. This paper describes both model tests and numerical simulations. A reduced scale model of a low specific speed pump-turbine was used for the performance tests, with comparisons to computational fluid dynamics(CFD) results. Predictions using the detached eddy simulation(DES) turbulence model, which is a combined Reynolds averaged Naviers-Stokes(RANS) and large eddy simulation(LES) model, are compared with the two-equation turbulence mode results. The external characteristics as well as the internal flow are for various guide vane openings to understand the unsteady flow along the so called S characteristics of a pump-turbine. Comparison of the experimental data with the CFD results for various conditions and times shows that DES model gives better agreement with experimental data than the two-equation turbulence model. For low flow conditions, the centrifugal forces and the large incident angle create large vortices between the guide vanes and the runner inlet in the runner passage, which is the main factor leading to the S-shaped characteristics. The turbulence model used here gives more accurate simulations of the internal flow characteristics of the pump-turbine and a more detailed force analysis which shows the mechanisms controlling of the S characteristics.

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

Science.gov (United States)

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

1971-01-01

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.

A comparison of the heat and mechanical energy of a heat-pump wind turbine system

Energy Technology Data Exchange (ETDEWEB)

Aybek, A.; Arslan, S.; Yildiz, E.; Atik, K. [University of Kahramanmaras (Turkey). Dept. of Agricultural Machinery

2000-07-01

While a variety of applications of wind energy have been studied in Turkey, no significant efforts have been made to utilize heat pumps for heat generation. The use of heat pumps in wind energy systems is worth considering because of the high efficiency of heat production. In this study, a directly coupled wind turbine-heat pump system was designed, constructed, and tested. Measurements determined the mechanical energy of the rotors of the wind turbine and the heat energy generated by the heat pump driven by the rotor shaft. Based on the comparisons between the power generated by the heat pump and the power of the Savonius rotors, it was found that the heat energy gained by the heat pump was four times greater than the mechanical energy obtained from the turbine. It was suggested that heat pumps could be efficiently used in wind energy systems. (Author)

Numerical simulation of hydrodynamics in a pump-turbine at off-design operating conditions in turbine mode

International Nuclear Information System (INIS)

Yan, J P; Seidel, U; Koutnik, J

2012-01-01

The hydrodynamics of a reduced-scaled model of a radial pump-turbine is investigated under off-design operating conditions, involving runaway and 'S-shape' turbine brake curve at low positive discharge. It is a low specific speed pump-turbine machine of Francis type with 9 impeller blades and 20 stay vanes as well as 20 guide vanes. The computational domain includes the entire water passage from the spiral casing inlet to the draft tube outlet. Completely structured hexahedral meshes generated by the commercial software ANSYS-ICEM are employed. The unsteady incompressible simulations are performed using the commercial code ANSYS-CFX13. For turbulence modeling the standard k-ε model is applied. The numerical results at different operating points are compared to the experimental results. The predicted pressure amplitude is in good agreement with the experimental data and the amplitude of normal force on impeller is in reasonable range. The detailed analysis reveals the onset of the flow instabilities when the machine is brought from a regular operating condition to runaway and turbine break mode. Furthermore, the rotating stall phenomena are well captured at runaway condition as well as low discharge operating condition with one stall cell rotating inside and around the impeller with about 70% of its frequency. Moreover, the rotating stall is found to be the effect of rotating flow separations developed in several consecutive impeller channels which lead to their blockage. The reliable simulation of S-curve characteristics in pump-turbines is a basic requirement for design and optimization at off-design operating conditions.

Analysis of vorticity dynamics for hump characteristics of a pump turbine model

Energy Technology Data Exchange (ETDEWEB)

Li, Deyou; Gong, Ruzhi; Wang, Hongjie; Han, Lei; Wei, Xianzhu; Qin, Daqing [School of Energy Science and Engineering, Harbin Institute of Technology, Harbin (China)

2016-08-15

Conventional parameters based on CFD methodology for the investigation on hump characteristics of a pump turbine cannot reflect the dynamic interaction mechanism between the runner and the fluid. This research presents a dynamic interaction mechanism of a pump turbine operating in the hump region. First, vorticity dynamic parameters were obtained based on the theory of vorticity dynamics. Second, 3-D unsteady flow simulations were performed in a full pump turbine model using the SST k-ω turbulence model, and numerical results have a good agreement with the experiments. Then, analysis was carried out to determine the relation between the vorticity dynamic parameters and hump characteristics. The results indicate that the theory of vorticity dynamics has an advantage in evaluating the dynamic performance of a pump turbine. The energy transfer between the runner and the fluid is through vorticity dynamic parameters-pressure and friction terms, in which the pressure term accounts for the most. Furthermore, vortex generation mainly results from the skin friction. Combining vorticity dynamic analysis with the method of Q-criterion indicates that hump characteristics are related to the reduction of the surface normal pressure work and vortex motion on the suction surfaces close to the leading edges in the runner, and the increase of skin friction work in the stay-guide vanes.

Modeling an autonomous wind turbine electric pump system

Directory of Open Access Journals (Sweden)

Andreea Forcos

2009-10-01

Full Text Available Being one of the variable renewable energy sources, wind energy integration can be made using storage methods. All of these have been developed during time, but one might be more accessible than others because is using a free natural resource, water. This is pump storage. The purpose of this paper is modeling an autonomous wind turbine connected to an electric pump, in the aim of storage, and finally the determination of the efficiency.

Numerical simulation of pressure fluctuation of a pump-turbine with MGV at no-load condition

International Nuclear Information System (INIS)

Liu, J T; Wang, L Q; Liu, S H; Sun, Y K; Wu, Y L

2012-01-01

In order to analyse the pressure fluctuation caused by misaligned guide vanes (MGV) during starting period at no-load condition, 3-D (three dimensional), unsteady flows in a pump-turbine were numerically studied. Pressure fluctuations of different points at no-load condition are obtained. Fast Fourier Transform(FFT) was used to analyse the frequency spectrum of pressure fluctuations. The amplitude and dominant frequency of pressure fluctuation at vaneless space between the runner and guide vane, as well as the inlet of draft tube, was investigated. The amplitude of pressure fluctuation of the pump-turbine with MGV device is twice that of synchronous vanes. This might be caused by the non-uniform flow in the pump-turbine due to the pre-opened guide vanes. The pump-turbine with synchronous vanes has a low frequency which is 0.33f n , while the low frequency changes into 0.63f n when the MGV device is used. The vortex rope in the draft tube is large than that of synchronize vanes. Resultsof pressure fluctuations with synchronous vanes agree with each other between computational and testing results. The numerical study of pressure fluctuations with MGV can provide a basic understanding for the improvement of the instability of a pump-turbine.

Prediction Method for the Complete Characteristic Curves of a Francis Pump-Turbine

Directory of Open Access Journals (Sweden)

Wei Huang

2018-02-01

Full Text Available Complete characteristic curves of a pump-turbine are essential for simulating the hydraulic transients and designing pumped storage power plants but are often unavailable in the preliminary design stage. To solve this issue, a prediction method for the complete characteristics of a Francis pump-turbine was proposed. First, based on Euler equations and the velocity triangles at the runners, a mathematical model describing the complete characteristics of a Francis pump-turbine was derived. According to multiple sets of measured complete characteristic curves, explicit expressions for the characteristic parameters of characteristic operating point sets (COPs, as functions of a specific speed and guide vane opening, were then developed to determine the undetermined coefficients in the mathematical model. Ultimately, by combining the mathematical model with the regression analysis of COPs, the complete characteristic curves for an arbitrary specific speed were predicted. Moreover, a case study shows that the predicted characteristic curves are in good agreement with the measured data. The results obtained by 1D numerical simulation of the hydraulic transient process using the predicted characteristics deviate little from the measured characteristics. This method is effective and sufficient for a priori simulations before obtaining the measured characteristics and provides important support for the preliminary design of pumped storage power plants.

Analysis of Pressure Fluctuations in a Prototype Pump-Turbine with Different Numbers of Runner Blades in Turbine Mode

Directory of Open Access Journals (Sweden)

Deyou Li

2018-06-01

Full Text Available In pump-turbines, high pressure fluctuation is one of the crucial instabilities, which is harmful to the stable and effective operation of the entire unit. Extensive studies have been carried out to investigate pressure fluctuations (amplitude and frequency at specific locations. However, limited research was conducted on the distribution of pressure fluctuations in turbine mode in a pump-turbine, as well as the influence of the number of runner blades on pressure fluctuations. Hence, in this study, three dimensional numerical simulations were performed to predict the distribution of pressure fluctuations with different numbers of runner blades in a prototype pump-turbine in turbine mode using the shear stress transport (SST k-ω turbulence model. Three operating points with the same hydraulic head and different mass flow rates were simulated. The distribution of pressure fluctuation components of blade passing frequency and its harmonics in the direction along the whole flow path, as well as along the circumferential direction, was presented. The mass flow rate and number of runner blades have great influence on the distribution of pressure fluctuations, especially at blade passing frequency along circumferential direction. The mass flow rate mainly affects the position of peak pressure fluctuations, while the number of runner blades mainly changes the number of peak pressure fluctuations. Additionally, the number of runner blades influences the dominant frequencies of pressure fluctuations especially in the spiral casing and draft tube.

Resonance investigation of pump-turbine during startup process

International Nuclear Information System (INIS)

He, L Y; Wang, Z W; Kurosawa, S; Nakahara, Y

2014-01-01

The causes of resonance of a certain model pump-turbine unit during startup process were investigated in this article. A three-dimensional full flow path analysis model which contains spiral case, stay vanes, guide vanes, runner, gaps outside the runner crown and band, and draft tube was constructed. The transient hydraulic excitation force of full flow path was analyzed under five conditions near the resonance region. Based on one-way fluid- structure interaction (FSI) analysis model, the dynamic stress characteristics of the pump-turbine runner was investigated. The results of pressure pulsation, vibration mode and dynamic stress obtained from simulation were consistent with the test results. The study indicated that the hydraulic excitation frequency (Z g *f n ) Hz due to rotor-stator interference corresponding to the natural frequency of 2ND+4ND runner mode is the main cause of resonance. The relationship among pressure pulsation, vibration mode and dynamic stress was discussed in this paper. The results revealed the underlying causes of the resonance phenomenon

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

International Nuclear Information System (INIS)

Kerschberger, P; Gehrer, A

2010-01-01

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.

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

Science.gov (United States)

Kerschberger, P.; Gehrer, A.

2010-08-01

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.

Entropy production analysis of hysteresis characteristic of a pump-turbine model

International Nuclear Information System (INIS)

Li, Deyou; Wang, Hongjie; Qin, Yonglin; Han, Lei; Wei, Xianzhu; Qin, Daqing

2017-01-01

Highlights: • An interesting hysteresis phenomenon was analyzed using entropy production theory. • A function was used to calculate the entropy production in the wall region. • Generation mechanism of the hump and hysteresis characteristics was obtained. - Abstract: The hydraulic loss due to friction and unstable flow patterns in hydro-turbines causes a drop in their efficiency. The traditional method for analyzing the hydraulic loss is by evaluating the pressure drop, which has certain limitations and cannot determine the exact locations at which the high hydraulic loss occurs. In this study, entropy production theory was adopted to obtain a detailed distribution of the hydraulic loss in a pump-turbine in the pump mode. In the past, the wall effects of entropy production were not considered, which caused larger errors as compared with the method of pressure difference. First, a wall equation was proposed to calculate the hydraulic loss in the wall region. The comparison of hydraulic loss calculated by entropy production and pressure difference revealed a better result. Then, through the use of the entropy production theory, the performance characteristics were determined for a pump-turbine with 19 mm guide vane opening, and the variation in the entropy production was obtained. Recently, an interesting phenomenon, i.e., a hysteresis characteristic, was observed in the hump region in pump-turbines. Research shows that the hysteresis characteristic is a result of the Euler momentum and hydraulic loss; the hydraulic loss accounts for a major portion of the hysteresis characteristic. Finally, the hysteresis characteristic in the hump region was analyzed in detail through the entropy production. The results showed that the hump characteristic and the accompanying hysteresis phenomenon are caused by backflow at the runner inlet and the presence of separation vortices close to the hub and the shroud in the stay/guide vanes, which is dependent on the direction of

Design of water pumping system by wind turbine for using in coastal areas of Bangladesh

Science.gov (United States)

Alam, Muhammad Mahbubul; Tasnim, Tamanna; Doha, Umnia

2017-06-01

In this work, a theoretical analysis has been carried out to analyze the prospect of Wind Pumping System (WPS) for using in coastal areas of Bangladesh. Wind speed data of three coastal areas of Bangladesh-Kutubdia, Patenga and Sathkhira has been analyzed and an optimal wind turbine viable for this wind speed range has been designed using the simulation software Q-blade. The simulated turbine is then coupled with a rotodynamic pump. The output of the Wind Pumping System (WPS) for the three coastal areas has been studied.

Counter-rotating type axial flow pump unit in turbine mode for micro grid system

International Nuclear Information System (INIS)

Kasahara, R; Takano, G; Komaki, K; Murakami, T; Kanemoto, T

2012-01-01

Traditional type pumped storage system contributes to adjust the electric power unbalance between day and night, in general. This serial research proposes the hybrid power system combined the wind power unit with the pump-turbine unit, to provide the constant output for the grid system, even at the suddenly fluctuating/turbulent wind. In the pumping mode, the pump should operate unsteadily at not only the normal but also the partial discharge. The operation may be unstable in the rising portion of the head characteristics at the lower discharge, and/or bring the cavitation at the low suction head. To simultaneously overcome both weak points, the authors have proposed a superior pump unit that is composed of counter-rotating type impellers and a peculiar motor with double rotational armatures. This paper discusses the operation at the turbine mode of the above unit. It is concluded with the numerical simulations that this type unit can be also operated acceptably at the turbine mode, because the unit works so as to coincide the angular momentum change through the front runners/impellers with that thorough the rear runners/impellers, namely to take the axial flow at not only the inlet but also the outlet without the guide vanes.

Using a Statistical-Numerical Procedure for the Selection of Pumps running as Turbines to be applied in Water Pipelines: Study Cases

Directory of Open Access Journals (Sweden)

Silvio Barbarelli

2018-06-01

Full Text Available A combined method using statistical and numerical models has been developed by the authors for selecting a pump running as turbine to be applied in micro-hydro plants. The data of the hydrological site chosen for the installation (head and capacity allow the calculation of two conversion factors which identify the pump to use successfully as turbine in that place. Then, a one-dimensional model, starting from data available on the pumps manufacturers catalogues, reconstructs a virtual geometry of the pump running as turbine, and calculates the performances curves, head vs. capacity, efficiency vs. capacity, useful for identifying the operating point. Two study cases are presented to apply the proposed methodology, concerning the feasibility of the installation of a pump running as turbine in the purifier water plants of Casali and Sersale, located at 1,000 m above sea level (Calabria, South Italy.The assessment of the annual energy yield gives a confirmation of the effectiveness and convenience of using pumps running as turbines.

Hydroacoustic simulation of rotor-stator interaction in resonance conditions in Francis pump-turbine

International Nuclear Information System (INIS)

Nicolet, C; Ruchonnet, N; Alligne, S; Avellan, F; Koutnik, J

2010-01-01

Combined effect of rotating pressure field related to runner blade and wakes of wicket gates leads to rotor stator interactions, RSI, in Francis pump-turbines. These interactions induce pressures waves propagating in the entire hydraulic machine. Superposition of those pressure waves may result in standing wave in the spiral casing and rotating diametrical mode in the guide vanes and can cause strong pressure fluctuations and vibrations. This paper presents the modeling, simulation and analysis of Rotor-Stator Interaction of a scale model of a Francis pump-turbine and related test rig using a one-dimensional approach. The hydroacoustic modeling of the Francis pump-turbine takes into account the spiral casing, the 20 guide vanes, the 9 rotating runner vanes. The connection between stationary and rotating parts is ensured by a valve network driven according to the unsteady flow distribution between guide vanes and runner vanes. Time domain simulations are performed for 2 different runner rotational speeds in turbine mode. The simulation results are analyzed in frequency domain and highlights hydroacoustic resonance between RSI excitations and the spiral case. Rotating diametrical mode in the vaneless gap and standing wave in the spiral case are identified. The influence of the resonance on phase and amplitude of pressure fluctuations obtained for both the spiral case and the vaneless gap is analyzed. The mode shape and frequencies are confirmed using eigenvalues analysis.

Energy Production by Means of Pumps As Turbines in Water Distribution Networks

Directory of Open Access Journals (Sweden)

Mauro Venturini

2017-10-01

Full Text Available This paper deals with the estimation of the energy production by means of pumps used as turbines to exploit residual hydraulic energy, as in the case of available head and flow rate in water distribution networks. To this aim, four pumps with different characteristics are investigated to estimate the producible yearly electric energy. The performance curves of Pumps As Turbines (PATs, which relate head, power, and efficiency to the volume flow rate over the entire PAT operation range, were derived by using published experimental data. The four considered water distribution networks, for which experimental data taken during one year were available, are characterized by significantly different hydraulic features (average flow rate in the range 10–116 L/s; average pressure reduction in the range 12–53 m. Therefore, energy production accounts for actual flow rate and head variability over the year. The conversion efficiency is also estimated, for both the whole water distribution network and the PAT alone.

Numerical study of similarity in prototype and model pumped turbines

International Nuclear Information System (INIS)

Li, Z J; Wang, Z W; Bi, H L

2014-01-01

Similarity study of prototype and model pumped turbines are performed by numerical simulation and the partial discharge case is analysed in detail. It is found out that in the RSI (rotor-stator interaction) region where the flow is convectively accelerated with minor flow separation, a high level of similarity in flow patterns and pressure fluctuation appear with relative pressure fluctuation amplitude of model turbine slightly higher than that of prototype turbine. As for the condition in the runner where the flow is convectively accelerated with severe separation, similarity fades substantially due to different topology of flow separation and vortex formation brought by distinctive Reynolds numbers of the two turbines. In the draft tube where the flow is diffusively decelerated, similarity becomes debilitated owing to different vortex rope formation impacted by Reynolds number. It is noted that the pressure fluctuation amplitude and characteristic frequency of model turbine are larger than those of prototype turbine. The differences in pressure fluctuation characteristics are discussed theoretically through dimensionless Navier-Stokes equation. The above conclusions are all made based on simulation without regard to the penstock response and resonance

High-resolution LES of the rotating stall in a reduced scale model pump-turbine

International Nuclear Information System (INIS)

Pacot, Olivier; Avellan, François; Kato, Chisachi

2014-01-01

Extending the operating range of modern pump-turbines becomes increasingly important in the course of the integration of renewable energy sources in the existing power grid. However, at partial load condition in pumping mode, the occurrence of rotating stall is critical to the operational safety of the machine and on the grid stability. The understanding of the mechanisms behind this flow phenomenon yet remains vague and incomplete. Past numerical simulations using a RANS approach often led to inconclusive results concerning the physical background. For the first time, the rotating stall is investigated by performing a large scale LES calculation on the HYDRODYNA pump-turbine scale model featuring approximately 100 million elements. The computations were performed on the PRIMEHPC FX10 of the University of Tokyo using the overset Finite Element open source code FrontFlow/blue with the dynamic Smagorinsky turbulence model and the no-slip wall condition. The internal flow computed is the one when operating the pump-turbine at 76% of the best efficiency point in pumping mode, as previous experimental research showed the presence of four rotating cells. The rotating stall phenomenon is accurately reproduced for a reduced Reynolds number using the LES approach with acceptable computing resources. The results show an excellent agreement with available experimental data from the reduced scale model testing at the EPFL Laboratory for Hydraulic Machines. The number of stall cells as well as the propagation speed corroborates the experiment

High-resolution LES of the rotating stall in a reduced scale model pump-turbine

Science.gov (United States)

Pacot, Olivier; Kato, Chisachi; Avellan, François

2014-03-01

Extending the operating range of modern pump-turbines becomes increasingly important in the course of the integration of renewable energy sources in the existing power grid. However, at partial load condition in pumping mode, the occurrence of rotating stall is critical to the operational safety of the machine and on the grid stability. The understanding of the mechanisms behind this flow phenomenon yet remains vague and incomplete. Past numerical simulations using a RANS approach often led to inconclusive results concerning the physical background. For the first time, the rotating stall is investigated by performing a large scale LES calculation on the HYDRODYNA pump-turbine scale model featuring approximately 100 million elements. The computations were performed on the PRIMEHPC FX10 of the University of Tokyo using the overset Finite Element open source code FrontFlow/blue with the dynamic Smagorinsky turbulence model and the no-slip wall condition. The internal flow computed is the one when operating the pump-turbine at 76% of the best efficiency point in pumping mode, as previous experimental research showed the presence of four rotating cells. The rotating stall phenomenon is accurately reproduced for a reduced Reynolds number using the LES approach with acceptable computing resources. The results show an excellent agreement with available experimental data from the reduced scale model testing at the EPFL Laboratory for Hydraulic Machines. The number of stall cells as well as the propagation speed corroborates the experiment.

Fluid-structure coupling in the guide vanes cascade of a pump-turbine scale model

International Nuclear Information System (INIS)

Roth, S; Hasmatuchi, V; Botero, F; Farhat, M; Avellan, F

2010-01-01

The present study concerns fluid-structure coupling phenomena occurring in a guide vane cascade of a pump-turbine scale model placed in the EPFL PF3 test rig. An advanced instrument set is used to monitor both vibrating structures and the surrounding flow. The paper highlights the interaction between vibrating guide vanes and the flow behavior. The pressure fluctuations in the stay vanes region are found to be strongly influenced by the amplitude of the vibrating guide vanes. Moreover, the flow induces different hydrodynamic damping on the vibrating guide vanes depending on the operating point of the pump-turbine.

Fluid-structure coupling in the guide vanes cascade of a pump-turbine scale model

Science.gov (United States)

Roth, S.; Hasmatuchi, V.; Botero, F.; Farhat, M.; Avellan, F.

2010-08-01

The present study concerns fluid-structure coupling phenomena occurring in a guide vane cascade of a pump-turbine scale model placed in the EPFL PF3 test rig. An advanced instrument set is used to monitor both vibrating structures and the surrounding flow. The paper highlights the interaction between vibrating guide vanes and the flow behavior. The pressure fluctuations in the stay vanes region are found to be strongly influenced by the amplitude of the vibrating guide vanes. Moreover, the flow induces different hydrodynamic damping on the vibrating guide vanes depending on the operating point of the pump-turbine.

Steam feeding redundancy for turbine-drives of feed pumps at WWER-1000 NPP

International Nuclear Information System (INIS)

Nesterov, Yu.V.; Shmukler, B.I.

1987-01-01

The system of steam supply for feed pump driving turbines (T) at the South Ukrainian Unit 1 according to the centralized redundancy principle is described. T is feeded through the collector of water auxiliary sytem (CWAS) to which steam from the third steam extraction line of turbine is supplied under thenormal regime. Under the reduction of turbine load, live steam from the steam generator is supplied to CWAS through the pressure regulator, possesing 10 s speed of responce. In this case the level reduction in the steam generator makes up 170 mm

Speed control of boiler feed water pump turbine based on gray correlation compensation

Energy Technology Data Exchange (ETDEWEB)

Zhou, Yun Long; Wang, Di; Zhou, Hai Chun [Northeast Dianli UniversityJilin (China)

2017-01-15

One of the most important controlled parameters of thermal power units is the boiler drum water level. Disturbances of feed water flow rate could cause instability of the drum water level. This study proposes the Gray correlation compensation (GCC) control technology for the Boiler feed water pump turbine (BFPT) to solve this problem. Simulation results indicate that the GCC controller outperforms the traditional proportional-integral-derivative controller when it encounters different disturbances. Furthermore, the GCC controller can rapidly switch to the high-pressure steam source to ensure that the drum water level is in the secure range during steam source switching of the BFPT.

Experimental investigation of vortex control with an axial jet in the draft tube of a model pump-turbine

International Nuclear Information System (INIS)

Kirschner, O; Schmidt, H; Ruprecht, A; Mader, R; Meusburger, P

2010-01-01

The operation of hydropower plants, especially of pump-storage plants, changes since the deregulation of the energy market. They are increasingly operating at off-design conditions in order to follow the demand in the electrical grid. Therefore the ability of hydropower plants handling the operation in a wide range of off-design conditions has become more important. In this context one problem is the vortex rope in the draft tube, especially for Francis turbines and pump-turbines running in part load. An experimental investigation in mitigation of the vortex rope phenomenon by injecting water axially in the centre of the draft tube on a pump-turbine model was carried out. Also the mitigation by additionally injected air in the centre of the draft tube was analysed. The results of the experimental investigation are focused on the reduction of the pressure fluctuations in the draft tube. In this paper two different part-load operating points were investigated. One of these operating points is a high part load operating point where a vortex rope exists. The other one is a low part load operating point, where the pressure fluctuation is not caused by a vortex rope. The results of the investigation show, that the injection of stabilizing water can mitigate the pressure fluctuation caused by a vortex rope. But the investigation of operating points where the pressure fluctuation is not caused by a vortex rope shows, that there is no significant reduction in the pressure fluctuation by this method. In these operating points the method of injecting additionally air reduces the pressure fluctuation better.

Experimental investigation of vortex control with an axial jet in the draft tube of a model pump-turbine

Energy Technology Data Exchange (ETDEWEB)

Kirschner, O; Schmidt, H; Ruprecht, A [Institute of Fluid Mechanics and Hydraulic Machinery, University of Stuttgart, Pfaffenwaldring 10, 70550 Stuttgart (Germany); Mader, R; Meusburger, P, E-mail: kirschner@ihs.uni-stuttgart.d [Vorarlberger Illwerke A G, atloggstrasse 36, 6780 Schruns (Austria)

2010-08-15

The operation of hydropower plants, especially of pump-storage plants, changes since the deregulation of the energy market. They are increasingly operating at off-design conditions in order to follow the demand in the electrical grid. Therefore the ability of hydropower plants handling the operation in a wide range of off-design conditions has become more important. In this context one problem is the vortex rope in the draft tube, especially for Francis turbines and pump-turbines running in part load. An experimental investigation in mitigation of the vortex rope phenomenon by injecting water axially in the centre of the draft tube on a pump-turbine model was carried out. Also the mitigation by additionally injected air in the centre of the draft tube was analysed. The results of the experimental investigation are focused on the reduction of the pressure fluctuations in the draft tube. In this paper two different part-load operating points were investigated. One of these operating points is a high part load operating point where a vortex rope exists. The other one is a low part load operating point, where the pressure fluctuation is not caused by a vortex rope. The results of the investigation show, that the injection of stabilizing water can mitigate the pressure fluctuation caused by a vortex rope. But the investigation of operating points where the pressure fluctuation is not caused by a vortex rope shows, that there is no significant reduction in the pressure fluctuation by this method. In these operating points the method of injecting additionally air reduces the pressure fluctuation better.

A Comparison of Prediction Methods for Design of Pump as Turbine for Small Hydro Plant: Implemented Plant

Science.gov (United States)

Naeimi, Hossein; Nayebi Shahabi, Mina; Mohammadi, Sohrab

2017-08-01

In developing countries, small and micro hydropower plants are very effective source for electricity generation with energy pay-back time (EPBT) less than other conventional electricity generation systems. Using pump as turbine (PAT) is an attractive, significant and cost-effective alternative. Pump manufacturers do not normally provide the characteristic curves of their pumps working as turbines. Therefore, choosing an appropriate Pump to work as a turbine is essential in implementing the small-hydro plants. In this paper, in order to find the best fitting method to choose a PAT, the results of a small-hydro plant implemented on the by-pass of a Pressure Reducing Valve (PRV) in Urmia city in Iran are presented. Some of the prediction methods of Best Efficiency Point of PATs are derived. Then, the results of implemented project have been compared to the prediction methods results and the deviation of from measured data were considered and discussed and the best method that predicts the specifications of PAT more accurately determined. Finally, the energy pay-back time for the plant is calculated.

Exergy, Economic and Environmental Analyses of Gas Turbine Inlet Air Cooling with a Heat Pump Using a Novel System Configuration

Directory of Open Access Journals (Sweden)

Mohammad Reza Majdi Yazdi

2015-10-01

Full Text Available Gas turbines incur a loss of output power during hot seasons due to high ambient air temperatures, and input air cooling systems are often used to partly offset this problem. Here, results are reported for an investigation of the utilization of a heat pump to cool the inlet air of a gas turbine compressor. The analyses are carried out for two climates: the city of Yazd, Iran, which has a hot, arid climate, and Tehran, Iran, which has a temperate climate. The heat pump input power is obtained from the gas turbine. The following parameters are determined, with and without the heat pump: net output power, first and second law efficiencies, quantities and costs of environmental pollutants, entropy generation and power generation. The results suggest that, by using the air-inlet cooling system, the mean output power increases during hot seasons by 11.5% and 10% for Yazd and Tehran, respectively, and that the costs of power generation (including pollution costs decrease by 11% and 10% for Yazd and Tehran, respectively. Also, the rate of generation of pollutants such as NOx and CO decrease by about 10% for Yazd and 35% for Tehran, while the average annual entropy generation rate increases by 9% for Yazd and 7% for Tehran, through air-inlet cooling. The average increase of the system first law efficiency is 2% and of the system second law efficiency is 1.5% with the inlet-air cooling system.

Effects of water compressibility on the pressure fluctuation prediction in pump turbine

International Nuclear Information System (INIS)

Yin, J L; Wang, D Z; Wang, L Q; Wu, Y L; Wei, X Z

2012-01-01

The compressible effect of water is a key factor in transient flows. However, it is always neglected in the unsteady simulations for hydraulic machinery. In light of this, the governing equation of the flow is deduced to combine the compressibility of water, and then simulations with compressible and incompressible considerations to the typical unsteady flow phenomenon (Rotor stator interaction) in a pump turbine model are carried out and compared with each other. The results show that water compressibility has great effects on the magnitude and frequency of pressure fluctuation. As the operating condition concerned, the compressibility of water will induce larger pressure fluctuation, which agrees better with measured data. Moreover, the lower frequency component of the pressure signal can only be captured with the combination of water compressibility. It can be concluded that water compressibility is a fatal factor, which cannot be neglected in the unsteady simulations for pump turbines.

Set-up of a pump as turbine use in micro-pumped hydro energy storage: a case of study in Froyennes Belgium

Science.gov (United States)

Morabito, A.; Steimes, J.; Bontems, O.; Zohbi, G. Al; Hendrick, P.

2017-04-01

Its maturity makes pumped hydro energy storage (PHES) the most used technology in energy storage. Micro-hydro plants (electricity production such as wind and solar power. This paper presents the design of a micro-PHES developed in Froyennes, Belgium, using a pump as turbine (PaT) coupled with a variable frequency driver (VFD). The methods adopted for the selection of the most suitable pump for pumping and reverse mode are compared and discussed. Controlling and monitoring the PaT performances represent a compulsory design phase in the analysis feasibility of PaT coupled with VFD in micro PHES plant. This study aims at answering technical research aspects of µ-PHES site used with reversible pumps.

Aeroelastic instability problems for wind turbines

DEFF Research Database (Denmark)

Hansen, Morten Hartvig

2007-01-01

This paper deals with the aeroelostic instabilities that have occurred and may still occur for modem commercial wind turbines: stall-induced vibrations for stall-turbines, and classical flutter for pitch-regulated turbines. A review of previous works is combined with derivations of analytical...... stiffness and chordwise position of the center of gravity along the blades are the main parameters for flutter. These instability characteristics are exemplified by aeroelastic stability analyses of different wind turbines. The review of each aeroelastic instability ends with a list of current research...... issues that represent unsolved aeroelostic instability problems for wind turbines. Copyright (c) 2007 John Wiley & Sons, Ltd....

Analysis of off-grid hybrid wind turbine/solar PV water pumping systems

Science.gov (United States)

While many remote water pumping systems exist (e.g. mechanical windmills, solar photovoltaic , wind-electric, diesel powered), very few combine both the wind and solar energy resources to possibly improve the reliability and the performance of the system. In this paper, off-grid wind turbine (WT) a...

Improved pump turbine transient behaviour prediction using a Thoma number-dependent hillchart model

International Nuclear Information System (INIS)

Manderla, M; Koutnik, J; Kiniger, K

2014-01-01

Water hammer phenomena are important issues for high head hydro power plants. Especially, if several reversible pump-turbines are connected to the same waterways there may be strong interactions between the hydraulic machines. The prediction and coverage of all relevant load cases is challenging and difficult using classical simulation models. On the basis of a recent pump-storage project, dynamic measurements motivate an improved modeling approach making use of the Thoma number dependency of the actual turbine behaviour. The proposed approach is validated for several transient scenarios and turns out to increase correlation between measurement and simulation results significantly. By applying a fully automated simulation procedure broad operating ranges can be covered which provides a consistent insight into critical load case scenarios. This finally allows the optimization of the closing strategy and hence the overall power plant performance

Improved pump turbine transient behaviour prediction using a Thoma number-dependent hillchart model

Science.gov (United States)

Manderla, M.; Kiniger, K.; Koutnik, J.

2014-03-01

Water hammer phenomena are important issues for high head hydro power plants. Especially, if several reversible pump-turbines are connected to the same waterways there may be strong interactions between the hydraulic machines. The prediction and coverage of all relevant load cases is challenging and difficult using classical simulation models. On the basis of a recent pump-storage project, dynamic measurements motivate an improved modeling approach making use of the Thoma number dependency of the actual turbine behaviour. The proposed approach is validated for several transient scenarios and turns out to increase correlation between measurement and simulation results significantly. By applying a fully automated simulation procedure broad operating ranges can be covered which provides a consistent insight into critical load case scenarios. This finally allows the optimization of the closing strategy and hence the overall power plant performance.

Performance Analysis of a Wind Turbine Driven Swash Plate Pump for Large Scale Offshore Applications

International Nuclear Information System (INIS)

Buhagiar, D; Sant, T

2014-01-01

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

Field Tests on Hydrodynamic and Hybrid Operation of a Bidirectional Thrust Bearing of a Pump-Turbine

Directory of Open Access Journals (Sweden)

Michał Wasilczuk

2017-12-01

Full Text Available In vertical shaft pump turbines operating in pumped storage power plants an important role is played by a thrust bearing. Due to the bidirectional character of operation, thrust bearing tilting pads have to be supported symmetrically, which is known to be unfavourable from the point of view of their performance. Large thrust bearings have to be carefully designed so as to minimise excessive thermo-elastic pad deformations. The research into fluid film thrust bearings has been quite extensive over the years, comprising theoretical studies of bearing properties with the use of more and more sophisticated calculation codes. On the other hand, the availability of experimental field data on bearing operation is limited, for obvious reasons. In this paper the authors present part of the results of extensive field tests of a large bearing of a pump-turbine they have conducted in a pumped storage power plant. Hopefully this data will be of interest to other researchers to compare theoretical predictions to measurement data.

Monitoring of Rotor-Stator Interaction in Pump-Turbine Using Vibrations Measured with On-Board Sensors Rotating with Shaft

Directory of Open Access Journals (Sweden)

Cristian G. Rodriguez

2014-01-01

Full Text Available Current trends in design of pump-turbines have led into higher rotor-stator interaction (RSI loads over impeller-runner. These dynamic loads are of special interest having produced catastrophic failures in pump-turbines. Determining RSI characteristics facilitates the proposal of actions that will prevent these failures. Pressure measurements all around the perimeter of the impeller-runner are appropriate to monitor and detect RSI characteristics. Unfortunately most installed pump-turbines are not manufactured with in-built pressure sensors in appropriate positions to monitor RSI. For this reason, vibration measurements are the preferred method to monitor RSI in industry. Usually vibrations are measured in two perpendicular radial directions in bearings where valuable information could be lost due to bearing response. In this work, in order to avoid the effect of bearing response on measurement, two vibration sensors are installed rotating with the shaft. The RSI characteristics obtained with pressure measurements were compared to those determined using vibration measurements. The RSI characteristics obtained with pressure measurements were also determined using vibrations measured rotating with shaft. These RSI characteristics were not possible to be determined using the vibrations measured in guide bearing. Finally, it is recommended to measure vibrations rotating with shaft to detect RSI characteristics in installed pump-turbines as a more practical and reliable method to monitor RSI characteristics.

Energy and exergy analysis of the turbo-generators and steam turbine for the main feed water pump drive on LNG carrier

International Nuclear Information System (INIS)

Mrzljak, Vedran; Poljak, Igor; Mrakovčić, Tomislav

2017-01-01

Highlights: • Two low-power steam turbines in the LNG carrier propulsion plant were investigated. • Energy and exergy efficiencies of both steam turbines vary between 46% and 62%. • The ambient temperature has a low impact on exergy efficiency of analyzed turbines. • The maximum efficiencies area of both turbines was investigated. • A method for increasing the turbo-generator efficiencies by 1–3% is presented. - Abstract: Nowadays, marine propulsion systems are mainly based on internal combustion diesel engines. Despite this fact, a number of LNG carriers have steam propulsion plants. In such plants, steam turbines are used not only for ship propulsion, but also for electrical power generation and main feed water pump drive. Marine turbo-generators and steam turbine for the main feed water pump drive were investigated on the analyzed LNG carrier with steam propulsion plant. The measurements of various operating parameters were performed and obtained data were used for energy and exergy analysis. All the measurements and calculations were performed during the ship acceleration. The analysis shows that the energy and exergy efficiencies of both analyzed low-power turbines vary between 46% and 62% what is significantly lower in comparison with the high-power steam turbines. The ambient temperature has a low impact on exergy efficiency of analyzed turbines (change in ambient temperature for 10 °C causes less than 1% change in exergy efficiency). The highest exergy efficiencies were achieved at the lowest observed ambient temperature. Also, the highest efficiencies were achieved at 71.5% of maximum developed turbo-generator power while the highest efficiencies of steam turbine for the main feed water pump drive were achieved at maximum turbine developed power. Replacing the existing steam turbine for the main feed water pump drive with an electric motor would increase the turbo-generator energy and exergy efficiencies for at least 1–3% in all analyzed

Pressure fluctuation prediction of a model pump turbine at no load opening by a nonlinear k-ε turbulence model

International Nuclear Information System (INIS)

Liu, J T; Zuo, Z G; Liu, S H; Wu, Y L

2014-01-01

In this paper, a new nonlinear k-ε turbulence model based on RNG k-ε turbulence model and Wilcox's k-ω turbulence model was proposed to simulate the unsteady flow and to predict the pressure fluctuation through a model pump turbine for engineering application. Calculations on a curved rectangular duct proved that the nonlinear k-ε turbulence model is applicable for high pressure gradient flows and large curvature flows. The numerically predicted relative pressure amplitude (peak to peak) in time domain to the pump turbine head at no load condition is very close to the experimental data. It is indicated that the prediction of the pressure fluctuation is valid by the present nonlinear k-ε method. The high pressure fluctuation in this area is the main issue for pump turbine design, especially at high head condition

CFD Modelling of a Pump as Turbine (PAT with Rounded Leading Edge Impellers for Micro Hydro Systems

Directory of Open Access Journals (Sweden)

Ismail Mohd Azlan

2017-01-01

Full Text Available A Pump as Turbine (PAT is one of micro hydro system components that is used to substitute a commercially available turbine due to its wide availability and low acquisition cost. However, PAT have high hydraulic losses due to differences in pump-turbine operation and hydraulic design. The fluid flowing inside the PAT is subjected to hydraulic losses due to the longer flow passage and unmatched fluid flow within the wall boundaries. This paper presents the effect of rounding the impeller leading edges of the pump on turbine performance. A CFD model of a PAT was designed to simulate virtual performance for the analysis. The aim of this study is to observe the internal hydraulic performance resulting from the changes in the performance characteristics. Highest efficiency was recorded at 17.0 l/s, an increase of 0.18%. The simulation results reveal that there is an improvement in hydraulic performance at overflow operation. The velocity vector visualization shows that there is a reduction in wake and consequently less flow separation along impeller flow passages. However, adjusting the sensitive impeller inlet geometry will also alter the velocity inlet vector and consequently change the velocity triangles for the turbo machinery system.

Efficiency improvement for wind energy pumped storage systems

DEFF Research Database (Denmark)

Forcos, A.; Marinescu, C.; Teodorescu, Remus

2011-01-01

Integrating wind energy into the grid may raise stability problems. Solutions for avoiding these situations are studied and energy storage methods are suitable for balancing the energy between the wind turbine and grid. In this paper, an autonomous wind turbine pumped storage system is presented...

Operating experience feedback report: Reliability of safety-related steam turbine-driven standby pumps. Commercial power reactors, Volume 10

International Nuclear Information System (INIS)

Boardman, J.R.

1994-10-01

This report documents a detailed analysis of failure initiators, causes and design features for steam turbine assemblies (turbines with their related components, such as governors and valves) which are used as drivers for standby pumps in the auxiliary feedwater systems of US commercial pressurized water reactor plants, and in the high pressure coolant injection and reactor core isolation cooling systems of US commercial boiling water reactor plants. These standby pumps provide a redundant source of water to remove reactor core heat as specified in individual plant safety analysis reports. The period of review for this report was from January 1974 through December 1990 for licensee event reports (LERS) and January 1985 through December 1990 for Nuclear Plant Reliability Data System (NPRDS) failure data. This study confirmed the continuing validity of conclusions of earlier studies by the US Nuclear Regulatory Commission and by the US nuclear industry that the most significant factors in failures of turbine-driven standby pumps have been the failures of the turbine-drivers and their controls. Inadequate maintenance and the use of inappropriate vendor technical information were identified as significant factors which caused recurring failures

Unstable behaviour of RPT when testing turbine characteristics in the laboratory

Science.gov (United States)

Nielsen, T. K.; Fjørtoft Svarstad, M.

2014-03-01

A reversible pump turbine is a machine that can operate in three modes of operation i.e. in pumping mode. in turbine mode and in phase compensating mode (idle speed). Reversible pump turbines have an increasing importance for regulation purposes for obtaining power balance in electric power systems. Especially in grids dominated by thermal energy. reversible pump turbines improve the overall power regulating ability. Increased use of renewables (wind-. wave- and tidal power plants) will utterly demand better regulation ability of the traditional water power systems. enhancing the use of reversible pump turbines. A reversible pump turbine is known for having incredible steep speed - flow characteristics. As the speed increases the flow decreases more than that of a Francis turbines with the same specific speed. The steep characteristics might cause severe stability problems in turbine mode of operation. Stability in idle speed is a necessity for phasing in the generator to the electric grid. In the design process of a power plant. system dynamic simulations must be performed in order to check the system stability. The turbine characteristics will have to be modelled with certain accuracy even before one knows the exact turbine design and have measured characteristics. A representation of the RPT characteristics for system dynamic simulation purposes is suggested and compared with measured characteristics. The model shows good agreement with RPT characteristics measured in The Waterpower Laboratory. Because of the S-shaped characteristics. there is a stability issue involved when measuring these characteristics. Without special measures. it is impossible to achieve stable conditions in certain operational points. The paper discusses the mechanism when using a throttle to achieve system stability. even if the turbine characteristics imply instability.

Unstable behaviour of RPT when testing turbine characteristics in the laboratory

International Nuclear Information System (INIS)

Nielsen, T K; Svarstad, M Fjørtoft

2014-01-01

A reversible pump turbine is a machine that can operate in three modes of operation i.e. in pumping mode. in turbine mode and in phase compensating mode (idle speed). Reversible pump turbines have an increasing importance for regulation purposes for obtaining power balance in electric power systems. Especially in grids dominated by thermal energy. reversible pump turbines improve the overall power regulating ability. Increased use of renewables (wind-. wave- and tidal power plants) will utterly demand better regulation ability of the traditional water power systems. enhancing the use of reversible pump turbines. A reversible pump turbine is known for having incredible steep speed - flow characteristics. As the speed increases the flow decreases more than that of a Francis turbines with the same specific speed. The steep characteristics might cause severe stability problems in turbine mode of operation. Stability in idle speed is a necessity for phasing in the generator to the electric grid. In the design process of a power plant. system dynamic simulations must be performed in order to check the system stability. The turbine characteristics will have to be modelled with certain accuracy even before one knows the exact turbine design and have measured characteristics. A representation of the RPT characteristics for system dynamic simulation purposes is suggested and compared with measured characteristics. The model shows good agreement with RPT characteristics measured in The Waterpower Laboratory. Because of the S-shaped characteristics. there is a stability issue involved when measuring these characteristics. Without special measures. it is impossible to achieve stable conditions in certain operational points. The paper discusses the mechanism when using a throttle to achieve system stability. even if the turbine characteristics imply instability

Effects of impeller diameter and rotational speed on performance of pump running in turbine mode

International Nuclear Information System (INIS)

Jain, Sanjay V.; Swarnkar, Abhishek; Motwani, Karan H.; Patel, Rajesh N.

2015-01-01

Highlights: • Experiments done between 900 and 1500 rpm with original, 10% and 20% trimmed impellers. • The performance of PAT was found better in speed range of 1000–1200 rpm. • Blade rounding led to 3–4% rise in efficiency at rated speed with existing impeller. • Correlation developed has predicted η BEP within ±10% of experimental results. - Abstract: The major limitations of mini/micro hydropower schemes is the higher cost of small capacity hydro turbines. Also, it is very cumbersome, time consuming and expensive to develop the site specific turbines corresponding to local site conditions in mini/micro hydro range. In such plants, small centrifugal pumps can be used in turbine mode by running in the reverse direction. The efficiency of pump as turbines (PATs) is usually lower than the conventional hydro turbines; however, there may be substantial decrease in the capital cost of the plant. Hydropower plants usually runs at part load for several months in a year due to insufficient water availability for the power generation. The application range of PAT can be widened if its part load and/or maximum efficiency can be improved. In the present study, experimental investigations are carried out on centrifugal pump running in turbine mode to optimize its geometric and operational parameters e.g. impeller diameter and rotational speed. The experiments were performed in the wide range of rotational speeds varying from 900 to 1500 rpm with original (∅ 250 mm), 10% trimmed (∅ 225 mm) and 20% trimmed (∅ 200 mm) impellers. Impeller trimming led to improvement in efficiency at part load operating conditions. The performance of PAT was found better at the lower speeds than that at the rated speed. The effects of blade rounding were studied in all the cases and it led to 3–4% rise in efficiency at rated speed with the original impeller. The empirical correlation is also developed for prediction of efficiency in terms of impeller diameter and rotational

Wind turbine operated sailboat

Energy Technology Data Exchange (ETDEWEB)

Hall, R.

1990-07-31

A wind powered boat is disclosed which incorporates a vertical axis rotary turbine. A shaft portion extends downwardly from the turbine to a water pump, with the boat being provided with a forwardly opening inlet and a rearwardly opening outlet from the water pump. When rotating, the turbine operates the pump by the shaft to draw in water through the inlet, thereby creating a low pressure area in front of the boat, and to force the water out through the outlet for propelling the boat. In a preferred embodiment, the boat has a catamaran construction or is a large ocean going vessel with enough width to provide a buffer to either side of the turbine, and the turbine is the Darrieus rotor type. The pump is a standard centrifugal type of pump. A self adjusting braking device for the turbine is also disclosed, which prevents over-rotation and is also capable of storing heat energy generated during braking. 4 figs.

Comparison of Different Approaches to Predict the Performance of Pumps As Turbines (PATs

Directory of Open Access Journals (Sweden)

Mauro Venturini

2018-04-01

Full Text Available This paper deals with the comparison of different methods which can be used for the prediction of the performance curves of pumps as turbines (PATs. The considered approaches are four, i.e., one physics-based simulation model (“white box” model, two “gray box” models, which integrate theory on turbomachines with specific data correlations, and one “black box” model. More in detail, the modeling approaches are: (1 a physics-based simulation model developed by the same authors, which includes the equations for estimating head, power, and efficiency and uses loss coefficients and specific parameters; (2 a model developed by Derakhshan and Nourbakhsh, which first predicts the best efficiency point of a PAT and then reconstructs their complete characteristic curves by means of two ad hoc equations; (3 the prediction model developed by Singh and Nestmann, which predicts the complete turbine characteristics based on pump shape and size; (4 an Evolutionary Polynomial Regression model, which represents a data-driven hybrid scheme which can be used for identifying the explicit mathematical relationship between PAT and pump curves. All approaches are applied to literature data, relying on both pump and PAT performance curves of head, power, and efficiency over the entire range of operation. The experimental data were provided by Derakhshan and Nourbakhsh for four different turbomachines, working in both pump and PAT mode with specific speed values in the range 1.53–5.82. This paper provides a quantitative assessment of the predictions made by means of the considered approaches and also analyzes consistency from a physical point of view. Advantages and drawbacks of each method are also analyzed and discussed.

Vertical axis wind turbine power regulation through centrifugally pumped lift spoiling

Science.gov (United States)

Klimas, P. C.; Sladky, J. F., Jr.

This paper describes an approach for lowering the rated windspeeds of Darrieus-type vertical axis wind turbines (VAWTs) whose blades are hollow aluminum extrusions. The blades, which when rotating act as centrifugal pumps, are fitted with a series of small perforations distributed along a portion of the blades' span. By valving the ends of the hollow blades, flow into the blade ends and out of the perforations may be controlled. This flow can induce premature aerodynamic stall on the blade elements, thereby reducing both the rated power of the turbine and its cost-of-energy. The concept has been proven on the Sandia National Laboratories 5-m diameter research VAWT and force balance and flow visualization wind tunnel tests have been conducted using a blade section designed for the VAWT application.

Sodium pumping: pump problems

International Nuclear Information System (INIS)

Guer, M.; Guiton, P.

Information on sodium pumps for LMFBR type reactors is presented concerning ring pump design, pool reactor pump design, secondary pumps, sodium bearings, swivel joints of the oscillating annulus, and thermal shock loads

Offshore Floating Wind Turbine-driven Deep Sea Water Pumping for Combined Electrical Power and District Cooling

Science.gov (United States)

Sant, T.; Buhagiar, D.; Farrugia, R. N.

2014-06-01

A new concept utilising floating wind turbines to exploit the low temperatures of deep sea water for space cooling in buildings is presented. The approach is based on offshore hydraulic wind turbines pumping pressurised deep sea water to a centralised plant consisting of a hydro-electric power system coupled to a large-scale sea water-cooled air conditioning (AC) unit of an urban district cooling network. In order to investigate the potential advantages of this new concept over conventional technologies, a simplified model for performance simulation of a vapour compression AC unit was applied independently to three different systems, with the AC unit operating with (1) a constant flow of sea surface water, (2) a constant flow of sea water consisting of a mixture of surface sea water and deep sea water delivered by a single offshore hydraulic wind turbine and (3) an intermittent flow of deep sea water pumped by a single offshore hydraulic wind turbine. The analysis was based on one year of wind and ambient temperature data for the Central Mediterranean that is known for its deep waters, warm climate and relatively low wind speeds. The study confirmed that while the present concept is less efficient than conventional turbines utilising grid-connected electrical generators, a significant portion of the losses associated with the hydraulic transmission through the pipeline are offset by the extraction of cool deep sea water which reduces the electricity consumption of urban air-conditioning units.

Offshore Floating Wind Turbine-driven Deep Sea Water Pumping for Combined Electrical Power and District Cooling

International Nuclear Information System (INIS)

Sant, T; Buhagiar, D; Farrugia, R N

2014-01-01

A new concept utilising floating wind turbines to exploit the low temperatures of deep sea water for space cooling in buildings is presented. The approach is based on offshore hydraulic wind turbines pumping pressurised deep sea water to a centralised plant consisting of a hydro-electric power system coupled to a large-scale sea water-cooled air conditioning (AC) unit of an urban district cooling network. In order to investigate the potential advantages of this new concept over conventional technologies, a simplified model for performance simulation of a vapour compression AC unit was applied independently to three different systems, with the AC unit operating with (1) a constant flow of sea surface water, (2) a constant flow of sea water consisting of a mixture of surface sea water and deep sea water delivered by a single offshore hydraulic wind turbine and (3) an intermittent flow of deep sea water pumped by a single offshore hydraulic wind turbine. The analysis was based on one year of wind and ambient temperature data for the Central Mediterranean that is known for its deep waters, warm climate and relatively low wind speeds. The study confirmed that while the present concept is less efficient than conventional turbines utilising grid-connected electrical generators, a significant portion of the losses associated with the hydraulic transmission through the pipeline are offset by the extraction of cool deep sea water which reduces the electricity consumption of urban air-conditioning units

Adaptive sliding mode back-stepping pitch angle control of a variable-displacement pump controlled pitch system for wind turbines.

Science.gov (United States)

Yin, Xiu-xing; Lin, Yong-gang; Li, Wei; Liu, Hong-wei; Gu, Ya-jing

2015-09-01

A variable-displacement pump controlled pitch system is proposed to mitigate generator power and flap-wise load fluctuations for wind turbines. The pitch system mainly consists of a variable-displacement hydraulic pump, a fixed-displacement hydraulic motor and a gear set. The hydraulic motor can be accurately regulated by controlling the pump displacement and fluid flows to change the pitch angle through the gear set. The detailed mathematical representation and dynamic characteristics of the proposed pitch system are thoroughly analyzed. An adaptive sliding mode pump displacement controller and a back-stepping stroke piston controller are designed for the proposed pitch system such that the resulting pitch angle tracks its desired value regardless of external disturbances and uncertainties. The effectiveness and control efficiency of the proposed pitch system and controllers have been verified by using realistic dataset of a 750 kW research wind turbine. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

Frequencies in the Vibration Induced by the Rotor Stator Interaction in a Centrifugal Pump Turbine

DEFF Research Database (Denmark)

Rodriguez, Cristian; Egusquiza, Eduard; Santos, Ilmar

2007-01-01

The highest vibration levels in large pump turbines are, in general, originated in the rotor stator interaction (RSI). This vibration has specific characteristics that can be clearly observed in the frequency domain: harmonics of the moving blade passing frequency and a particular relationship am...

Radial loads and axial thrusts on centrifugal pumps

International Nuclear Information System (INIS)

Anon.

1986-01-01

The proceedings of a seminar organised by the Power Industries Division of the IMechE are presented in this text. Complete contents: Review of parameters influencing hydraulic forces on centrifugal impellers; The effect of fluid forces at various operation conditions on the vibrations of vertical turbine pumps; A review of the pump rotor axial equilibrium problem - some case studies; Dynamic hydraulic loading on a centrifugal pump impeller; Experimental research on axial thrust loads of double suction centrifugal pumps; A comparison of pressure distribution and radial loads on centrifugal pumps; A theoretical and experimental investigation of axial thrusts within a multi-stage centrifugal pump

Energy efficiency analysis of steam ejector and electric vacuum pump for a turbine condenser air extraction system based on supervised machine learning modelling

International Nuclear Information System (INIS)

Strušnik, Dušan; Marčič, Milan; Golob, Marjan; Hribernik, Aleš; Živić, Marija; Avsec, Jurij

2016-01-01

Highlights: • Steam ejector pump and electric liquid ring vacuum pump are analysed and modelled. • A supervised machine learning models by using real process data are applied. • The equation of ejector pumped mass flow from steam turbine condenser was solved. • The loss of specific energy capable of work in a SEPS or LRVP component was analysed. • The economic efficiency analysis per different coal heating values was made. - Abstract: This paper compares the vapour ejector and electric vacuum pump power consumptions with machine learning algorithms by using real process data and presents some novelty guideline for the selection of an appropriate condenser vacuum pump system of a steam turbine power plant. The machine learning algorithms are made by using the supervised machine learning methods such as artificial neural network model and local linear neuro-fuzzy models. The proposed non-linear models are designed by using a wide range of real process operation data sets from the CHP system in the thermal power plant. The novelty guideline for the selection of an appropriate condenser vacuum pumps system is expressed in the comparative analysis of the energy consumption and use of specific energy capable of work. Furthermore, the novelty is expressed in the economic efficiency analysis of the investment taking into consideration the operating costs of the vacuum pump systems and may serve as basic guidelines for the selection of an appropriate condenser vacuum pump system of a steam turbine.

Comprehensive Structural Dynamic Analysis of the SSME/AT Fuel Pump First-Stage Turbine Blade

Science.gov (United States)

Brown, A. M.

1998-01-01

A detailed structural dynamic analysis of the Pratt & Whitney high-pressure fuel pump first-stage turbine blades has been performed to identify the cause of the tip cracking found in the turbomachinery in November 1997. The analysis was also used to help evaluate potential fixes for the problem. Many of the methods available in structural dynamics were applied, including modal displacement and stress analysis, frequency and transient response to tip loading from the first-stage Blade Outer Gas Seals (BOGS), fourier analysis, and shock spectra analysis of the transient response. The primary findings were that the BOGS tip loading is impulsive in nature, thereby exciting many modes of the blade that exhibit high stress at the tip cracking location. Therefore, a proposed BOGS count change would not help the situation because a clearly identifiable resonance situation does not exist. The recommendations for the resolution of the problem are to maintain the existing BOGS count, eliminate the stress concentration in the blade due to its geometric design, and reduce the applied load on the blade by adding shiplaps in the BOGS.

Economical justification in usage of heat pump connected to the turbine cooling system

International Nuclear Information System (INIS)

Mijakovski, Vladimir; Josifovski, Vasko

2008-01-01

Orangery or greenhouse presents building with micro climate quite different from the external, that is internal temperature is substantially different from the external air temperature. Part of the solar energy is absorbed by plants and ground, part is transformed to heat energy, thus heating internal air. That is the reason, depending on the local climate conditions, heat radiation covers 30 to 60 % of the total heat energy needs for the orangery. Economical justification for the connection of heat pump to the cold end of the turbine in the orangerie's (green-house) heating system is presented in this paper. Rationality from the usage of low-temperature heat energy from the turbine's cold-end comes from techno-economical and ecological aspect. (Author)

Numerical study of pressure fluctuations in different guide vanes' opening angle in pump mode of a pump turbine

International Nuclear Information System (INIS)

Sun, Y K; Zuo, Z G; Liu, S H; Wu, Y L; Liu, J T

2012-01-01

A numerical model based on a pumped storage power station was built to develop the numerical simulation, to analyze the pressure fluctuations in a pump turbine in different guide vanes' opening angle. The different guide vanes' opening angles were simulated using the SST k-ω turbulence model and SIMPLEC Pressure-Velocity coupling scheme. The pressure sensor were placed in mainly three positions, they are: bottom ring between runner and the wicket gates, downstream and left side in the draft tube cone below the runner. All the peak to peak values of pressure fluctuation meet signal probability of 97%. The frequency is gained by Fast Fourier Transform. The pressure fluctuations in different positions of the model in pump condition were showed when the guide vanes' opening angels were different. The simulation results confirmed the results gained in model tests. The results show that pressure fluctuations in design opening angle were much lower than those in off design opening angle. The main source of pressure fluctuations between runner and guide vanes is rotor stator interaction. While a lower frequency is the main frequency of the pressure fluctuation in draft tube.

An improved efficiency of fuzzy sliding mode control of permanent magnet synchronous motor for wind turbine generator pumping system

International Nuclear Information System (INIS)

Benchabane, F.; Titaouine, A.; Guettaf, A.; Yahia, K.; Taibi, D.; Bennis, O.

2012-01-01

This paper presents an analysis by which the dynamic performances of a permanent magnet synchronous motor (PMSM) motor is controlled through a hysteresis current loop and an outer speed loop with different controllers. The dynamics of the wind turbine pumping drive system with (PI) and a fuzzy sliding mode (FSM) speed controllers are presented. In order to optimize the overall system efficiency, a maximum power point tracker is also used. Simulation is carried out by formatting the mathematical model for wind turbine generator, motor and pump load. The results for such complicated and nonlinear system, with fuzzy sliding mode speed controller show improvement in transient response of the PMSM drive over conventional PI. The effectiveness of the FSM controller is also demonstrated. (author)

Nuclear power/water pumping-up composite power plant

International Nuclear Information System (INIS)

Okamura, Kiyoshi.

1995-01-01

In a nuclear power/water pumping-up composite power plant, a reversible pump for pumping-up power generation connected to a steam turbine is connected to an upper water reservoir and a lower water reservoir. A pumping-up steam turbine for driving the turbine power generator, a hydraulic pump for driving water power generator by water flowing from the upper water reservoir and a steam turbine for driving the pumping-up pump by steams from a nuclear reactor are disposed. When power demand is small during night, the steam turbine is rotated by steams of the reactor, to pump up the water in the lower water reservoir to the upper water reservoir by the reversible pump. Upon peak of power demand during day time, power is generated by the steams of the reactor, as well as the reversible pump is rotated by the flowing water from the upper water reservoir to conduct hydraulic power generation. Alternatively, hydraulic power generation is conducted by flowing water from the upper reservoir. Since the number of energy conversion steps in the combination of nuclear power generation and pumping-up power generation is reduced, energy loss is reduced and utilization efficiency can be improved. (N.H.)

Aging related degradation in turbine drives and governors for safety related pumps

International Nuclear Information System (INIS)

Cox, D.F.

1991-01-01

This study is being performed to examine the relationship between time dependent degradation, and current industry practices in the areas of maintenance, surveillance, and operation of stem turbine drive for safety related pumps. These pumps are located in the Auxiliary Feedwater (AFW) system for pressurized water reactor (PWR) plants, and the Reactor Core Isolation Cooking (RCIC) and High Pressure Coolant Injection (HPCI) systems for Boiling Water Reactor (BWR) facilities. This research has been conducted by examining current information in the Nuclear Plant Reliability Data System (NPRDS), reviewing Licensee Event Reports, thoroughly investigating contacts with operating plant personnel, and by personal observation. This information was reviewed to determine the cause of each reported event and the method of discovery. From this data attempts have been made at determining the predictability of events and possible preventive measures that may be implemented

Power maximization of an asynchronous wind turbine with a variable speed feeding a centrifugal pump

International Nuclear Information System (INIS)

Ouchbel, T.; Zouggar, S.; Elhafyani, M.L.; Seddik, M.; Oukili, M.; Aziz, A.; Kadda, F.Z.

2014-01-01

Highlights: • The pumping system studied contain a WT, a SEIG, an IM and a CP. • The system must ensure the water pumping in optimum conditions despite the wind speed. • A steady state study and a practical testing are performed to resolve the control law. • A MPPT is proposed on the basis of static converter SVC. - Abstract: This article focuses on the study of a pumping system compound of a wind turbine, a self-excited induction generator (SEIG), an induction motor (IM), and a centrifugal pump (CP), which aims to ensure the water pumping in optimum conditions regardless the wind speed. As a first step, a study in the steady and dynamic state to determine the control law is examined. As a second step, and so as to achieve a maximum energy flow we have proposed a Maximum Power Point Tracking (MPPT) algorithm based on a static converter SVC. As a final step, experimental and simulation results are discussed to show the reliability of the system proposed

Centrifugal pumps and allied machinery

CERN Document Server

Anderson, HH

1994-01-01

This book will be of vital interest to all engineers and designers concerned with centrifugal pumps and turbines. Including statistical information derived from 20000 pumps and 700 turbines with capacities of 5gpm to 5000000gpm, this book offers the widest range and scope of information currently available. Statistical analyses suggest practical methods of increasing pump performance and provide valuable data for new design aspects.

Compressible simulation of rotor-stator interaction in pump-turbines

International Nuclear Information System (INIS)

Yan, J; Koutnik, J; Seidel, U; Huebner, B

2010-01-01

This work investigates the influence of water compressibility on pressure pulsations induced by rotor-stator interaction (RSI) in hydraulic machinery, using the commercial CFD solver ANSYS-CFX. A pipe flow example with harmonic velocity excitation at the inlet plane is simulated using different grid densities and time step sizes. Results are compared with a validated code for hydraulic networks (SIMSEN). Subsequently, the solution procedure is applied to a simplified 2.5-dimensional pump-turbine configuration in model scale with an adapted speed of sound. Pressure fluctuations are compared with numerical and experimental data based on prototype scale. The good agreement indicates that the scaling of acoustic effects with an adapted speed of sound works well. Finally, the procedure is applied to a 3-dimensional pump configuration in model scale. Pressure fluctuations are compared with results from prototype measurements. Compared to incompressible computations, compressible simulations provide similar pressure fluctuations in vaneless space, but pressure fluctuations in spiral case and penstock may be much higher. With respect to pressure fluctuation amplitudes along the centerline of runner channels, incompressible solutions exhibit a linear decrease while compressible solutions exhibit sinusoidal distributions with maximum values at half the channel length, coinciding with analytical solutions of one-dimensional acoustics.

Pump power plants for wind age; Pumpekraftverk for vindalderen

Energy Technology Data Exchange (ETDEWEB)

Bakken, Marte

2010-07-01

Power giant Sira-Kvina, Norway, prepares to expand Tonstad power station with pump options to save energy and benefit from price fluctuations in the electricity market. How pump power plant works; Consists mainly of two reservoirs at different heights. Bottom placed a turbine that can run both ways, or a pump and turbine mounted on the generator. The generator acts as an engine of pumping. When saving energy, water is pumped up to the highest magazine. The energy is extracted by letting the water run back through the turbine. Amount of energy that can be saved depends on the height difference between the magazines and magazine size, while the effect is determined by the size of the pump turbine.(AG)

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

International Nuclear Information System (INIS)

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

2012-01-01

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.

Liquid-phase problems in steam turbine LP stages

International Nuclear Information System (INIS)

Blanc-Feraud, P.

1978-01-01

Wet steam formation owing to incipient condensation in final steam turbine pressure stages results in a loss of efficiency and possible rotor blading erosion. The effects of erosion are now clearly understood and quite easily counteracted, but loss of thermodynamics, mechanical and aerodynamic efficiency is still a problem. Only the final LP stages of conventional power station plant operate with wet steam, whereas nuclear plant turbines use it to produce most of their total output [fr

A review on adsorption heat pump: Problems and solutions

OpenAIRE

Demir, Hasan; Mobedi, Moghtada; Ülkü, Semra

2008-01-01

Adsorption heat pumps have considerably sparked attentions in recent years. The present paper covers the working principle of adsorption heat pumps, recent studies on advanced cycles, developments in adsorbent-adsorbate pairs and design of adsorbent beds. The adsorbent-adsorbate pair features for in order to be employed in the adsorption heat pumps are described. The adsorption heat pumps are compared with the vapor compression and absorption heat pumps. The problems and troubles of adsorptio...

A Performance Prediction Method for Pumps as Turbines (PAT Using a Computational Fluid Dynamics (CFD Modeling Approach

Directory of Open Access Journals (Sweden)

Emma Frosina

2017-01-01

Full Text Available Small and micro hydropower systems represent an attractive solution for generating electricity at low cost and with low environmental impact. The pump-as-turbine (PAT approach has promise in this application due to its low purchase and maintenance costs. In this paper, a new method to predict the inverse characteristic of industrial centrifugal pumps is presented. This method is based on results of simulations performed with commercial three-dimensional Computational Fluid Dynamics (CFD software. Model results have been first validated in pumping mode using data supplied by pump manufacturers. Then, the results have been compared to experimental data for a pump running in reverse. Experimentation has been performed on a dedicated test bench installed in the Department of Civil Construction and Environmental Engineering of the University of Naples Federico II. Three different pumps, with different specific speeds, have been analyzed. Using the model results, the inverse characteristic and the best efficiency point have been evaluated. Finally, results have been compared to prediction methods available in the literature.

High-speed flow visualization in a pump-turbine under off-design operating conditions

International Nuclear Information System (INIS)

Hasmatuchi, V; Roth, S; Botero, F; Avellan, F; Farhat, M

2010-01-01

The flow hydrodynamics in a low specific speed radial pump-turbine reduced scale model is experimentally investigated under off-design operating conditions in generating mode. Wall pressure measurements, in the stator, synchronized with high-speed flow visualizations in the vaneless space between the impeller and the guide vanes using air bubbles injection are performed. When starting from the best efficiency point and increasing the runner speed, a significant increase of the pressure fluctuations is observed mainly in channels between wicket gates. The spectral analysis shows a rise of one stall cell, rotating with about 70% of the impeller frequency, at runaway, which further increases as the zero discharge condition is approached. Then a specific image processing technique is detailed and applied to create a synthetic instantaneous view of the flow pattern on the entire guide vanes circumference for an operating point in turbine-brake mode, where backflow and vortices accompany the stall passage.

An initial examination of aging related degradation in turbine drives and governors for safety related pumps

International Nuclear Information System (INIS)

Cox, D.F.

1991-01-01

This study is being performed to examine the relationship between time dependent degradation, and current industry practices in the areas of maintenance, surveillance, and operation of steam turbine drives for safety related pumps. These pumps are located in the Auxiliary Feedwater (AFW) system for pressurized water reactor (PWR) plants, and the Reactor Core Isolation Cooling (RCIC) and High Pressure Coolant Injection (HPCI) systems for Boiling Water Reactor (BWR) facilities. This research has been conducted by examining current information in NPRDS, reviewing Licensee Event Reports, and thoroughly investigating contacts with operating plant personnel, and by personal observation. The reported information was reviewed to determine the cause of the event and the method of discovery. From this data attempts have been made at determining the predictability of events and possible preventive measures that may be implemented. Findings in a recent study on the Auxiliary Feedwater System (NUREG/CR-5404) indicate that the turbine drive is the single largest contributor to AFW system degradation. Recent improvements in maintenance practices and procedures, combined with a stabilization of the design seem to indicate that this equipment can be a reliable component in safety systems

The measured field performances of eight different mechanical and air-lift water-pumping wind-turbines

Energy Technology Data Exchange (ETDEWEB)

Kentfield, J.A.C. [Univ. of Calgary, Alberta (Canada)

1996-12-31

Results are presented of the specific performances of eight, different, water-pumping wind-turbines subjected to impartial tests at the Alberta Renewable Energy Test Site (ARETS), Alberta, Canada. The results presented which were derived from the test data, obtained independently of the equipment manufacturers, are expressed per unit of rotor projected area to eliminate the influence of machine size. Hub-height wind speeds and water flow rates for a common lift of 5.5 m (18 ft) constitute the essential test data. A general finding was that, to a first approximation, there were no major differences in specific performance between four units equipped with conventional reciprocating pumps two of which employed reduction gearing and two of which did not. It was found that a unit equipped with a Moyno pump performed well but three air-lift machines had, as was expected, poorer specific performances than the more conventional equipment. 10 refs., 9 figs.

Turbine rotors inspection problems associated with independent inspection

International Nuclear Information System (INIS)

Delgado, J.O.; Martinez, C.A.

1990-01-01

As is well know, the serious problems affecting turbine-generator set rotors and moving parts, such as stress-corrosion cracking and/or the phenomena of creep/fatigue, have led the companies possessing these components to make considerable investments in terms of economy and human resources with a view to finding means for control and solutions. The fact that certain countries, such as Spain, have a limited number of fossil-fuelled and/or nuclear plants, with different suppliers and designs, means that the control and solving of such problems necessarily imply significant technological dependence and, consequently, that the resources used imply high associated costs that is most cases have to be paid in overseas currencies. This fact led several Spanish plant owners to propose that Tecnatom carry out an R ampersand D project aimed at developing and integral turbine rotor inspection and evaluation system designed to reduce technological dependence in this area through the application of in-house technology. This project identified as PC-850059 has been subsidized by the Spanish authorities through The Interministerial Commission of Science ampersand Technology. This article describes the developments achieved and the difficulties inherent to independent turbine rotor inspection and evaluation

Solar-powered turbocompressor heat pump system

Science.gov (United States)

Landerman, A.M.; Biancardi, F.R.; Melikian, G.; Meader, M.D.; Kepler, C.E.; Anderson, T.J.; Sitler, J.W.

1982-08-12

The turbocompressor comprises a power turbine and a compressor turbine having respective rotors and on a common shaft, rotatably supported by bearings. A first working fluid is supplied by a power loop and is expanded in the turbine. A second working fluid is compressed in the turbine and is circulated in a heat pump loop. A lubricant is mixed with the second working fluid but is excluded from the first working fluid. The bearings are cooled and lubricated by a system which circulates the second working fluid and the intermixed lubricant through the bearings. Such system includes a pump, a thermostatic expansion valve for expanding the working fluid into the space between the bearings, and a return conduit system for withdrawing the expanded working fluid after it passes through the bearings and for returning the working fluid to the evaporator. A shaft seal excludes the lubricant from the power turbine. The power loop includes a float operable by liquid working fluid in the condenser for controlling a recirculation valve so as to maintain a minimum liquid level in the condenser, while causing a feed pump to pump most of the working fluid into the vapor generator. The heat pump compressor loop includes a float in the condenser for operating and expansion valve to maintain a minimum liquid working fluid level in the condenser while causing most of the working fluid to be expanded into the evaporator.

Reversible pumped hydro - benefits and challenges

Energy Technology Data Exchange (ETDEWEB)

Nielsen, Torbjoern K.; Walseth, Eve C.

2010-07-01

Full text: The Norwegian hydro power system is dominated with high head turbines, Pelton and Francis with high capacity in the reservoirs. Originally they were built for secure energy supply. In the system there are also reversible pump turbine (RPT) plants where in times with spare energy, made it possible to pump water from the lower reservoir to the higher. Again the idea was to secure energy supply, which meant pumping in early autumn to fill the reservoirs for winter. In the recent years, a more active use of the RPT plants has been actualized. The free market made price difference between night and day interesting, hence a more frequent pumping was desirable. In the coming years, new-renewable energy sources will utterly enhance a more active use of the RPT plants. More active use of the RPT plants means more frequent starts and stops, both in pumping and in turbine mode. There are a lot of challenges in adopting a new strategy for operating the machinery. More effective start equipment is required. The machinery will be exposed to more frequent dynamic loads; the turbines will be run at part- and full load. The existing RPT plants are connected to huge reservoirs. That means the RPTs are not only for short sighted power regulations, as many RPT-plants in Europe, but are also capable for a substantial energy production. In Norway, the nature is very suitable for RPT plants, both in connection with existing power plants, were reservoirs and conduits are already established, and standing alone with a minimum of energy production. RPTs are, as a design, a compromise between effective generating and stable as well as effective pumping. Stable pumping often results in very steep flow-speed characteristics when operating as a turbine. When dealing with hydraulic transients these characteristics cause a higher change in flow and torque leading to instability during start-up and possible off-design operation point. The instability slows down the synchronization

Turbine and its turbine control system of full scope simulator for Qinshan 300 MW Nuclear Power Unit

International Nuclear Information System (INIS)

Zhang Dongwei; Zhu Jinping

1996-01-01

The simulation for Qinshan 300 MW Nuclear Power Unit turbine and turbine control system is briefly introduced. The simulation system includes lube oil system, jacking oil pump system, turning gear system, turbine supervisor system and turbine control system. It not only correctly simulates the process of turbine normal start up, operation, and shut down, but also the response of turbine under the malfunction conditions

The Problem of Ensuring Reliability of Gas Turbine Engines

Science.gov (United States)

Nozhnitsky, Yu A.

2018-01-01

Requirements to advanced engines for civil aviation are discussing. Some significant problems of ensuring reliability of advanced gas turbine engines are mentioned. Special attention is paid to successful utilization of new materials and critical technologies. Also the problem of excluding failure of engine part due to low cycle or high cycle fatigue is discussing.

Vertical pump turbine oil environmental evaluation

Energy Technology Data Exchange (ETDEWEB)

Culver, G.

1991-04-01

In Oregon low-temperature geothermal injection well construction, siting and receiving formations requires approval by the Water Resources Department (OWRD). In addition, the Oregon Department of Environmental Quality (ODEQ) has regulations concerning injection. Conversations with the OWRD and ODEQ representatives indicated they were very concerned about the potential for contamination of the geothermal (and cooler but hydraulically connected) aquifers by oils and grease. Their primary concern was over the practice of putting paraffin, motor oils and other hydrocarbons in downhole heat exchanger (DHE) wells to prevent corrosion. They also expressed considerable concern about the use of oil in production well pumps since the fluids pumped would be injected. Oregon (and Idaho) prohibit the use of oil-lubricated pumps for public water supplies except in certain situations where non-toxic food-grade lubricants are used. Since enclosed-lineshaft oil-lubricated pumps are the mainstay of direct-use pumping equipment, the potential for restricting their use became a concern to the Geo-Heat Center staff. An investigation into alternative pump lubrication schemes and development of rebuttals to potential restrictions was proposed and approved as a contract task. (SM)

Measuring the Dynamic Characteristics of a Low Specific Speed Pump—Turbine Model

Directory of Open Access Journals (Sweden)

Eve Cathrin Walseth

2016-03-01

Full Text Available This paper presents results from an experiment performed to obtain the dynamic characteristics of a reversible pump-turbine model. The characteristics were measured in an open loop system where the turbine initially was run on low rotational speed before the generator was disconnected allowing the turbine to go towards runaway. The measurements show that the turbine experience damped oscillations in pressure, speed and flow rate around runaway corresponding with presented stability criterion in published literature. Results from the experiment is reproduced by means of transient simulations. A one dimensional analytical turbine model for representation of the pump-turbine is used in the calculations. The simulations show that it is possible to reproduce the physics in the measurement by using a simple analytical model for the pump-turbine as long as the inertia of the water masses in the turbine are modeled correctly.

Performance of a 10 kilowatt wind-electric water pumping system for irrigating crops

Energy Technology Data Exchange (ETDEWEB)

Vick, B.D.; Clark, R.N. [Conservation and Production Research Lab., Bushland, TX (United States); Molla, S. [Texas A& M Univ., College Station, TX (United States)

1997-12-31

A 10 kW wind-electric water pumping system was tested for field crop irrigation at pumping depths from 50 to 120 m. The wind turbine for this system used a permanent magnet alternator that powered off-the-shelf submersible motors and pumps without the use of an inverter. Pumping performance was determined at the USDA-Agricultural Research Service (ARS), Wind Energy Laboratory in Bushland, TX for the 10 kW wind turbine using a pressure valve and a pressure tank to simulate different pumping depths. Pumping performance was measured for two 10 kW wind turbines of the same type at farms near the cities of Garden City, TX and Stiles, TX. The pumping performance data collected at these actual wells compared favorably with the data collected at the USDA-ARS, Wind Energy Laboratory. If utility generated electricity was accessible, payback on the wind turbine depended on the cost of utility generated electricity and the transmission line extension cost.

Numerical Research on Effects of Splitter Blades to the Influence of Pump as Turbine

Directory of Open Access Journals (Sweden)

Yang Sun-Sheng

2012-01-01

Full Text Available Centrifugal pumps can be operated in reverse as small hydropower recovery turbines and are cheaper than bespoke turbines due to their ease of manufacture. Splitter blades technique is one of the techniques used in flow field optimization and performance enhancement of rotating machinery. To understand the effects of splitter blades to the steady and unsteady influence of PAT, numerical research was performed. 3D Navier-Stokes solver CFX was used in the performance prediction and analysis of PAT’s performance. Results show that splitter blades have a positive impact on PAT’s performance. With the increase of splitter blades, its required pressure head is dropped and its efficiency is increased. Unsteady pressure field analysis and comparison show that the unsteady pressure field within PAT is improved when splitter blades are added to impeller flow passage. To verify the accuracy of numerical prediction methods, an open PAT test rig was built at Jiangsu University. The PAT was manufactured and tested. Comparison between experimental and numerical results shows that the discrepancy between numerical and experimental results is acceptable. CFD can be used in the performance prediction and optimization of PAT.

Enhanced Component Performance Study: Turbine-Driven Pumps 1998–2014

Energy Technology Data Exchange (ETDEWEB)

Schroeder, John Alton [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2015-11-01

This report presents an enhanced performance evaluation of turbine-driven pumps (TDPs) at U.S. commercial nuclear power plants. The data used in this study are based on the operating experience failure reports from fiscal year 1998 through 2014 for the component reliability as reported in the Institute of Nuclear Power Operations (INPO) Consolidated Events Database (ICES). The TDP failure modes considered are failure to start (FTS), failure to run less than or equal to one hour (FTR=1H), failure to run more than one hour (FTR>1H), and normally running systems FTS and failure to run (FTR). The component reliability estimates and the reliability data are trended for the most recent 10-year period while yearly estimates for reliability are provided for the entire active period. Statistically significant increasing trends were identified for TDP unavailability, for frequency of start demands for standby TDPs, and for run hours in the first hour after start. Statistically significant decreasing trends were identified for start demands for normally running TDPs, and for run hours per reactor critical year for normally running TDPs.

Underground Pumped Hydroelectric Storage (UPHS). Program report, April 1-September 30, 1979. ANL Activity No. 49964

Energy Technology Data Exchange (ETDEWEB)

Blomquist, C.A.; Frigo, A.A.; Tam, S.W.; Clinch, J.M.

1979-10-01

The Argonne National Laboratory Underground Pumped Hydroelectric Storage activities for the second half of FY 1979 are described. Activities include program management and support, subcontract work, and systems studies. Information is given on the preliminary design, hydraulic performance, and cost of high-head, 350-MW capacity, single- and two-stage reversible, Francis-type pump turbines. Similar information is also presented on 350- and 500-MW capacity, multistage, unregulated, reversible, pump turbines. An assessment of the application potential of controlled-flow rate pumps and pump turbines is included. The effects of the charge/discharge ratio of a pumped stoage plant is also discussed.

Modular pump-turbine concept supporting the integration of renewable energy sources in a decentralised grid; Modulare Pumpturbine als Unterstuetzung bei der Einbindung alternativer Energien ins dezentrale Stromnetz

Energy Technology Data Exchange (ETDEWEB)

Doujak, Eduard; Unterberger, Philipp; Bauer, Christian [Technische Univ. Wien (Austria). Inst. fuer Energietechnik und Thermodynamik

2012-11-01

The integration of renewable energy systems in Europe leads to several challenges in the energy market. Energy storage for stable grid operation has become a necessity. Pumped storage is the only technology available today that is able to store large amounts of energy efficiently and with low specific storage costs. The Vienna University of Technology is currently investigating how existing artificial lakes for snow production could be integrated in pumped storage production systems. A new modular pump turbine concept and its application prospects are presented. (orig.)

Pumped Storage Hydro Power Plant Cierny Vah

International Nuclear Information System (INIS)

Regula, E.

1998-01-01

In this leaflet the pump-storage power plant Cierny Vah is presented. A Cierny Vah pumped storage power plant (PSP) has been designed and built for providing the reliable and quality electric energy supply and for covering load changes of an electrification system. (ES). It is mainly the pumped storage hydro power plants plants which in our conditions are the sources operatively covering the sudden changes of the ES load from the ecological, economic but mainly from the operational point of view. The electric energy generation volume is not the primary standpoint but especially their control functions in the ES. During the building of the Cierny Vah PSP the peak operation with the daily accumulation, participation in frequency control and output in ES and the compensation function in ES were to be its main tasks. After putting it into operation by especially after its becoming independent of the Slovak ES in 1994 the static functions (energy generation from pumping, balance output reserves, daily control, ...) gave way to dynamic functions which gained greater importance. After interconnection of the ES with the UCPTE West European Association in which there are besides other things, the strict criteria for observing balance outputs, the main functions of PSPs are as follows: (1) Dynamic services for ES; (2) Dispatching reserve for the fall out of the greatest ES block; (3) Observing the foreign cooperation balance agreed; (4) Compensation of peaks and also of sudden daily load diagram reductions. Technical parameters of the upper and lower reservoir are described. The hydro power plant is a body lower reservoir. In it there are six vertical pumping aggregates in the three machine layout: the motor-generator - the turbine - the pump. Between the turbine and the pump there is a hydraulically controlled claw clutch engaging at rest and disengaging also during the aggregate operation. During pumping air is involved inside the turbine. The Francis turbines have a

Automatic regulation of the feedwater turbo-pump capacity for the single-turbine 1000 MW NPP unit

International Nuclear Information System (INIS)

Pavlysh, O.N.; Garbuzov, I.P.; Reukov, Yu.N.

1985-01-01

A schematic of the flow regulators (FR) of feedwater turbo-pumps (FTP) for the single-turbine 1000 MW NPP unit is presented. The FR operate in response to feedwoter signals from FTP or in response to FTP rotor rotational speed and control automatic speed governars. The FR automatic regulation ensures limitation of FTP rotor maximum rotational speed at a feedwater flow rate excess equal to 3600 T/h. The transients in the automatic regulation system are considered. Production tests of FTP FR confirmed the FR operation reliability and the right choice of the regulator concept and structure

Advanced Instrumentation for Measuring Fluid-Structure Coupling Phenomena in the Guide Vanes Cascade of a Pump-Turbine Scale Model

OpenAIRE

Roth, Steven; Hasmatuchi, Vlad; Botero, Francisco; Farhat, Mohamed; Avellan, François

2010-01-01

In the present study, the fluid-structure coupling is investigated in the guide vanes of a pump-turbine scale model placed in one of the test rigs of the Laboratory for Hydraulic Machines (EPFL) in Lausanne. The paper focuses on the advanced instrumentation used to get reliable and complete fluid-structure coupling results. Semi-conductor strain gages are installed on three guide vanes which are especially weakened to account for stronger fluid-structure coupling phenomena. These are statical...

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

International Nuclear Information System (INIS)

Cook, T.C.; Hecker, G.E.

1997-02-01

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

LH2 pump component development testing in the electric pump room at test cell C inducer no. 1

Science.gov (United States)

Andrews, F. X.; Brunner, J. J.; Kirk, K. G.; Mathews, J. P.; Nishioka, T.

1972-01-01

The characteristics of a turbine pump for use with the nuclear engine for rocket vehicles are discussed. It was determined that the pump will be a two stage centrifugal pump with both stages having backswept impellers and an inducer upstream of the first stage impeller. The test program provided demonstration of the ability of the selected design to meet the imposed requirements.

Pumps for nuclear power stations

International Nuclear Information System (INIS)

Ogura, Shiro

1979-01-01

16 nuclear power plants are in commercial operation in Japan, and nuclear power generation holds the most important position among various substitute energies. Hereafter also, it is expected that the construction of nuclear power stations will continue because other advantageous energy sources are not found. In this paper, the outline of the pumps used for BWR plants is described. Nuclear power stations tend to be large scale to reduce the construction cost per unit power output, therefore the pumps used are those of large capacity. The conditions to be taken in consideration are high temperature, high pressure, radioactive fluids, high reliability, hydrodynamic performances, aseismatic design, relevant laws and regulations, and quality assurance. Pumps are used for reactor recirculation system, control rod driving hydraulic system, boric acid solution injecting system, reactor coolant purifying system, fuel pool cooling and purifying system, residual heat removing system, low pressure and high pressure core spraying systems, and reactor isolation cooling system, for condensate, feed water, drain and circulating water systems of turbines, for fresh water, sea water, make-up water and fire fighting services, and for radioactive waste treating system. The problems of the pumps used for nuclear power stations are described, for example, the requirement of high reliability, the measures to radioactivity and the aseismatic design. (Kako, I.)

Logic problems and solutions for memory signal of SEC pump in FQNP

International Nuclear Information System (INIS)

Lu Yanfei; Dang Xiaoqiang; Zhou Li; Ye Aiai

2014-01-01

In the Fuqing nuclear power plant, as a nuclear safety function system, the essential service water system is set two trains, and there are two pumps in each train. These pumps can be switched automatically according to the operation conditions. The signal which performs the automatic switch function called memory signal. This paper introduces the definition and role of the memory signal firstly, and then analyzes the logic of the two mutual backup SEC pumps, and the implementation method based on DCS platform. Finally, this paper presents the problems of memory signal during the commissioning and operation. Meanwhile, this paper proposes solutions to solve these problems, and analyzes the risk of the solutions, as well the significance for later units. (authors)

Investigations of unsteady flow in the draft tube of the pump- turbine model using laser Doppler anemometry

International Nuclear Information System (INIS)

Kaznacheev, A; Kuznetsov, I

2014-01-01

The measurements and video observation of unsteady flow in the draft tube cone of the pump-turbine model were conducted in the Laboratory of Water Turbines, property of OJSC ''Power machines'' - ''LMZ''. The prototype head was about 250 m. The experiments were performed for the turbine mode of operation. Measurements were taken for the unit speed value n11 corresponding to rated head in the generating mode of operation, for a wide range of guide vanes openings at loads ranging from partial to maximum value. The researches of the velocity field in function of the Thoma number were carried out in some operating conditions. The mean values and RMS deviations of the velocity components were the results of laser measurements. The curves of the intensity of the vortex versus the guide vane opening and the Thoma number were plotted. The energy velocity spectra were presented for the points at which the most pronounced frequency precession of the helical axial vortex was observed. Video recording and laser Doppler anemometry were made in the operating conditions of the developed cavitation. Based on the results of video observations and energy spectra obtained via LDA, vortex frequencies were determined i.e. the frequencies of the vortex precession under the runner in the draft tube cone

Pumped storage

International Nuclear Information System (INIS)

Strauss, P.L.

1991-01-01

The privately financed 1,000 MW Rocky Point Pumped Storage Project located in central Colorado, USA, will be one of the world's highest head, 2,350 feet reversible pump/turbine projects. The project will offer an economical supply of peaking power and spinning reserve power to Colorado and other southwestern states. This paper describes how the project will be made compatible with the environmental conditions in the project area and the type of terrestrial mitigation measures that are being proposed for those situations where the project impacts the environment, either temporarily or permanently

Pumped storage system model and experimental investigations on S-induced issues during transients

Science.gov (United States)

Zeng, Wei; Yang, Jiandong; Hu, Jinhong

2017-06-01

Because of the important role of pumped storage stations in the peak regulation and frequency control of a power grid, pump turbines must rapidly switch between different operating modes, such as fast startup and load rejection. However, pump turbines go through the unstable S region in these transition processes, threatening the security and stability of the pumped storage station. This issue has mainly been investigated through numerical simulations, while field experiments generally involve high risks and are difficult to perform. Therefore, in this work, the model test method was employed to study S-induced security and stability issues for a pumped storage station in transition processes. First, a pumped storage system model was set up, including the piping system, model units, electrical control systems and measurement system. In this model, two pump turbines with different S-shaped characteristics were installed to determine the influence of S-shaped characteristics on transition processes. The model platform can be applied to simulate any hydraulic transition process that occurs in real power stations, such as load rejection, startup, and grid connection. On the experimental platform, the S-shaped characteristic curves were measured to be the basis of other experiments. Runaway experiments were performed to verify the impact of the S-shaped characteristics on the pump turbine runaway stability. Full load rejection tests were performed to validate the effect of the S-shaped characteristics on the water-hammer pressure. The condition of one pump turbine rejecting its load after another defined as one-after-another (OAA) load rejection was performed to validate the possibility of S-induced extreme draft tube pressure. Load rejection experiments with different guide vane closing schemes were performed to determine a suitable scheme to adapt the S-shaped characteristics. Through these experiments, the threats existing in the station were verified, the

Fuqing nuclear power of nuclear steam turbine generating unit No.1 at the implementation and feedback

International Nuclear Information System (INIS)

Cao Yuhua; Xiao Bo; He Liu; Huang Min

2014-01-01

The article introduces the Fuqing nuclear power of nuclear steam turbine generating unit no.l purpose, range of experience, experiment preparation, implementation, feedback and response. Turn of nuclear steam turbo-generator set flush, using the main reactor coolant pump and regulator of the heat generated by the electric heating element and the total heat capacity in secondary circuit of reactor coolant system (steam generator secondary side) of saturated steam turbine rushed to 1500 RPM, Fuqing nuclear power of nuclear steam turbine generating unit no.1 implementation of the performance of the inspection of steam turbine and its auxiliary system, through the test problems found in the clean up in time, the nuclear steam sweep turn smooth realization has accumulated experience. At the same time, Fuqing nuclear power of nuclear steam turbine generating unit no.1 at turn is half speed steam turbine generator non-nuclear turn at the first, with its smooth realization of other nuclear power steam turbine generator set in the field of non-nuclear turn play a reference role. (authors)

Gas turbine engine with three co-axial turbine rotors in the same gas-stream

Energy Technology Data Exchange (ETDEWEB)

Kronogaard, S.O.

1978-06-01

A gas turbine engine with three coaxial rotors in the same gas passage designed for automative purposes is described. The first turbine rotor is rather small and does not supply all the power for compression at full load. It could be made from ceramic materials. The second rotor is mounted on a tubular axle and used for propulsion through a planetary gear. The third rotor is also mounted on a separate tubular axle and is used for driving auxillary machines pumps, i.e., generator, heat exchanger, etc.. It also delivers, through a thin shaft inside the second axle, extra power to the compressor, at full load. This turbine also rotates the vehicle stands still, if the second turbine is locked. The second and third turbines are rotating in opposite directions. Shaft bearings are air-stream supported. The turbine housing is made from light metal with internal surfaces in contact with gas or air and are covered with a layer of ceramics.

CFD Simulation and Optimization of Very Low Head Axial Flow Turbine Runner

Directory of Open Access Journals (Sweden)

Yohannis Mitiku Tobo

2015-10-01

Full Text Available The main objective of this work is Computational Fluid Dynamics (CFD modelling, simulation and optimization of very low head axial flow turbine runner  to be used to drive  a centrifugal pump of turbine-driven pump. The ultimate goal of the optimization is to produce a power of 1kW at head less than 1m from flowing  river to drive centrifugal pump using mechanical coupling (speed multiplier gear directly. Flow rate, blade numbers, turbine rotational speed, inlet angle are parameters used in CFD modeling,  simulation and design optimization of the turbine runner. The computed results show that power developed by a turbine runner increases with increasing flow rate. Pressure inside the turbine runner increases with flow rate but, runner efficiency increases for some flow rate and almost constant thereafter. Efficiency and power developed by a runner drops quickly if turbine speed increases due to higher pressure losses and conversion of pressure energy to kinetic energy inside the runner. Increasing blade number increases power developed but, efficiency does not increase always. Efficiency increases for some blade number and drops down due to the fact that  change in direction of the relative flow vector at the runner exit, which decreases the net rotational momentum and increases the axial flow velocity.

Sicle software. Pumps and blowers modelling

International Nuclear Information System (INIS)

Faulot, J.P.; Pastorini, S.

1993-10-01

The SICLE software includes a simplified modelization for pumps located on fluid circuits. This modelization is based on operating specifications (four quadrants), on energy conservation equation and on the second law of dynamics. The pump is considered like a punctual component without storage of mass or energy. In that case, it is the simplest punctual component of the different elementary modules of SICLE. Nevertheless, for a user, it represents one of the most complex component to model because of the many geometrical (driving or not by motor, turbine with or without coupling, etc...) and functional possibilities (operating in the four quadrants, motor specifications, turbines specifications, internal loss values, etc...). (authors). 4 figs., 1 ref

Trailing edge devices to improve performance and increase lifetime of wind-electric water pumping systems

Energy Technology Data Exchange (ETDEWEB)

Vick, B.D.; Clark, R.N. [USDA-Agricultural Research Service, Bushland, TX (United States)

1996-12-31

Trailing edge flaps were applied to the blades of a 10 kW wind turbine used for water pumping to try to improve the performance and decrease the structural fatigue on the wind turbine. Most small wind turbines (10 kW and below) use furling (rotor turns out of wind similar to a mechanical windmill) to protect the wind turbine from overspeed during high winds. Some small wind turbines, however, do not furl soon enough to keep the wind turbine from being off line part of the time in moderately high wind speeds (10 - 16 m/s). As a result, the load is disconnected and no water is pumped at moderately high wind speeds. When the turbine is offline, the frequency increases rapidly often causing excessive vibration of the wind turbine and tower components. The furling wind speed could possibly be decreased by increasing the offset between the tower centerline and the rotor centerline, but would be a major and potentially expensive retrofit. Trailing edge flaps (TEF) were used as a quick inexpensive method to try to reduce the furling wind speed and increase the on time by reducing the rotor RPM. One TEF configuration improved the water pumping performance at moderately high wind speeds, but degraded the pumping performance at low wind speeds which resulted in little change in daily water volume. The other TEF configuration differed very little from the no flap configuration. Both TEF configurations however, reduced the rotor RPM in high wind conditions. The TEF, did not reduce the rotor RPM by lowering the furling wind speed as hoped, but apparently did so by increasing the drag which also reduced the volume of water pumped at the lower wind speeds. 6 refs., 9 figs.

Small hydraulic turbine drives

Science.gov (United States)

Rostafinski, W. A.

1970-01-01

Turbine, driven by the fluid being pumped, requires no external controls, is completely integrated into the flow system, and has bearings which utilize the main fluid for lubrication and cooling. Torque capabilities compare favorably with those developed by positive displacement hydraulic motors.

Functional Problems and Maintenance Operations of Hydraulic Turbines

Directory of Open Access Journals (Sweden)

Liliana Topliceanu

2016-02-01

Full Text Available The exploitation in good conditions of the hydroelectric power plant imposes a rigorous maintenance of equipment and operating facilities, primarily of the turbine. The efficiency of the turbine is strongly affected by any defects which could occur during the operation. The paper makes a synthesis of the most frequent failures which have occurred during the functioning of Kaplan turbines plant and the required maintenance plan that has to be adopted. The maintenance rules for the optimal working of these turbines are also emphasized.

Heat pump heating with heat pumps driven by combustion engines or turbines

Energy Technology Data Exchange (ETDEWEB)

Hein, K

1977-01-27

The heat pump described is driven by a gas Otto cycle engine, or a gas- or light- or heavy-oil fired Diesel engine. The claim refers to the use of waste heat of the engines by feeding into the input circuit of the heat pump. In addition, a drive by an electrical motor-generator or power production can be selected at times of peak load in the electrical supply network.

Effect of non-condensable gas on heat transfer in steam turbine condenser and modelling of ejector pump system by controlling the gas extraction rate through extraction tubes

International Nuclear Information System (INIS)

Strušnik, Dušan; Golob, Marjan; Avsec, Jurij

2016-01-01

Graphical abstract: Control of the amount of the pumped gases through extraction tubes. The connecting locations interconnect the extraction tubes for STC gas pumping. The extraction tubes are fitted with 3 control valves to control the amount of the pumped gas depending on the temperature of the pumped gas. The amount of the pumped gas increases through the extraction tubes, where the pumped gases are cooler and decreases, at the same time, through the extraction tubes, where the pumped gases are warmer. As a result, pumping of a larger amount of NCG is ensured and of a smaller amount of CG, given that the NCG concentration is the highest on the colder places. This way, the total amount of the pumped gases from the STC can be reduced, the SEPS operates more efficiently and consumes less energy for its operation. - Highlights: • Impact of non-condensable gas on heat transfer in a steam turbine condenser. • The ejector system is optimised by selecting a Laval nozzle diameter. • Simulation model of the control of the amount of pumped gases through extraction tubes. • Neural network and fuzzy logic systems used to control gas extraction rate. • Simulation model was designed by using real process data from the thermal power plant. - Abstract: The paper describes the impact of non-condensable gas (NCG) on heat transfer in a steam turbine condenser (STC) and modelling of the steam ejector pump system (SEPS) by controlling the gas extraction rate through extraction tubes. The ideal connection points for the NCG extraction from the STC are identified by analysing the impact of the NCG on the heat transfer and measuring the existing system at a thermal power plant in Slovenia. A simulation model is designed using the Matlab software and Simulink, Neural Net Work, Fuzzy Logic and Curve Fitting Toolboxes, to control gas extraction rate through extraction tubes of the gas pumped from the STC, thus optimising the operation of the steam ejector pump system (SEPS). The

Sustainable application of renewable sources in water pumping systems: Optimized energy system configuration

International Nuclear Information System (INIS)

Ramos, J.S.; Ramos, H.M.

2009-01-01

Eighteen years ago, in Portugal, the expenses in a water supply system associated with energy consumption were quite low. However, with the successive crises of energy fuel and the increase of the energy tariff as well as the water demand, the energy consumption is becoming a larger and a more important part of the total budget of water supply pumping systems. Also, new governmental policies, essentially in developed countries, are trying to implement renewable energies. For these reasons, a case-study in Portugal of a water pumping system was analysed to operate connected to solar and wind energy sources. A stand-alone and a grid-connected systems were tested. The stand alone was compared with the cost of extending the national electric grid. In the grid-connected system two solutions were analysed, one with a water turbine and another without. To be able to implement a water turbine, a larger water pump was needed to pump the necessary water as for consumption as for energy production. For the case analysed the system without a water turbine proved to be more cost-effective because the energy tariff is not yet so competitive as well as the cost of water turbines

Performance of a centrifugal pump running in inverse mode

Energy Technology Data Exchange (ETDEWEB)

Fernandez, J. [Universidad de Extramadura, Badajoz (Spain). Departamento de Electronica e Ingenieria Electromecanica; Blanco, E.; Parrondo, J. [Oviedo Univ. (Spain). Departamento de Energia; Stickland, M.; Scanlon, T.J. [Strathclyde Univ., Glasgow (United Kingdom). Dept. of Mechanical Engineering

2004-08-01

This paper presents the functional characterization of a centrifugal pump used as a turbine. It shows the characteristics of the machine involved at several rotational speeds, comparing the respective flows and heads. In this way, it is possible to observe the influence of the rotational speed on efficiency, as well as obtaining the characteristics at constant head and runaway speed. Also, the forces actuating on the impeller were studied. An uncertainty analysis was made to assess the accuracy of the results. The research results indicate that the turbine characteristics can be predicted to some extent from the pump characteristics, that water flows out of the runner free of swirl flow at the best efficiency point, and that radial stresses are lower than in pump mode. (author)

Pump system characterization and reliability enhancement

International Nuclear Information System (INIS)

Staunton, R.H.

1998-01-01

Pump characterization studies were performed at the Oak Ridge National Laboratory (ORNL) to review and analyze six years (1990-1995) of data from pump systems at domestic nuclear plants. The studies considered not only pumps and pump motors but also pump-related circuit breakers and turbine drives (i.e., the pump system). One significant finding was that the number of 'significant' failures of the pump circuit breaker exceeds the number of significant failures of the pump itself. The study also shows how regulatory code testing was designed for the pump only and therefore did not lead to the discovery of other significant pump system failures. Potential diagnostic technologies, both experimental and mature, suitable for on-line and off-line pump testing were identified. The study does not select or recommend technologies but proposes diagnostic technologies and monitoring techniques that should be further evaluated/developed for making meaningful and critically-needed improvements in the reliability of the pump system. (author)

Process pump operating problems and equipment failures, F-Canyon Reprocessing Facility, Savannah River Plant

International Nuclear Information System (INIS)

Durant, W.S.; Starks, J.B.; Galloway, W.D.

1987-02-01

A compilation of operating problems and equipment failures associated with the process pumps in the Savannah River Plant F-Canyon Fuel Reprocessing Facility is presented. These data have been collected over the 30-year operation of the facility. An analysis of the failure rates of the pumps is also presented. A brief description of the pumps and the data bank from which the information was sorted is also included

Variable speed drives for pumps used in intensive pond culture systems

Science.gov (United States)

Prior to about 2010, the only large pumps on most catfish farms were those associated with the water supply. Water from wells is usually pumped to the surface using single-speed, vertical, lineshaft turbine pumps powered by three phase, electric motors. Since 2010, several catfish farmers have bui...

Design and performance analysis of gas and liquid radial turbines

Science.gov (United States)

Tan, Xu

In the first part of the research, pumps running in reverse as turbines are studied. This work uses experimental data of wide range of pumps representing the centrifugal pumps' configurations in terms of specific speed. Based on specific speed and specific diameter an accurate correlation is developed to predict the performances at best efficiency point of the centrifugal pump in its turbine mode operation. The proposed prediction method yields very good results to date compared to previous such attempts. The present method is compared to nine previous methods found in the literature. The comparison results show that the method proposed in this paper is the most accurate. The proposed method can be further complemented and supplemented by more future tests to increase its accuracy. The proposed method is meaningful because it is based both specific speed and specific diameter. The second part of the research is focused on the design and analysis of the radial gas turbine. The specification of the turbine is obtained from the solar biogas hybrid system. The system is theoretically analyzed and constructed based on the purchased compressor. Theoretical analysis results in a specification of 100lb/min, 900ºC inlet total temperature and 1.575atm inlet total pressure. 1-D and 3-D geometry of the rotor is generated based on Aungier's method. 1-D loss model analysis and 3-D CFD simulations are performed to examine the performances of the rotor. The total-to-total efficiency of the rotor is more than 90%. With the help of CFD analysis, modifications on the preliminary design obtained optimized aerodynamic performances. At last, the theoretical performance analysis on the hybrid system is performed with the designed turbine.

A Novel Pumped Hydro Combined with Compressed Air Energy Storage System

Directory of Open Access Journals (Sweden)

Erren Yao

2013-03-01

Full Text Available A novel pumped hydro combined with compressed air energy storage (PHCA system is proposed in this paper to resolve the problems of bulk energy storage in the wind power generation industry over an area in China, which is characterised by drought and water shortages. Thermodynamic analysis of the energy storage system, which focuses on the pre-set pressure, storage volume capacity, water air volume ratio, pump performance, and water turbine performance of the storage system, is also presented. This paper discovers how such parameters affect the performance of the whole system. The ideal performance of this novel system has the following advantages: a simple, highly effective and low cost structure, which is comparable to the efficiency of a traditional pumped hydro storage system. Research results show a great solution to the current storage constraints encountered in the development of the wind power industry in China, which have been widely recognised as a bottleneck in the wind energy storage industry.

Pressure fluctuation prediction in pump mode using large eddy simulation and unsteady Reynolds-averaged Navier–Stokes in a pump–turbine

Directory of Open Access Journals (Sweden)

De-You Li

2016-06-01

Full Text Available For pump–turbines, most of the instabilities couple with high-level pressure fluctuations, which are harmful to pump–turbines, even the whole units. In order to understand the causes of pressure fluctuations and reduce their amplitudes, proper numerical methods should be chosen to obtain the accurate results. The method of large eddy simulation with wall-adapting local eddy-viscosity model was chosen to predict the pressure fluctuations in pump mode of a pump–turbine compared with the method of unsteady Reynolds-averaged Navier–Stokes with two-equation turbulence model shear stress transport k–ω. Partial load operating point (0.91QBEP under 15-mm guide vane opening was selected to make a comparison of performance and frequency characteristics between large eddy simulation and unsteady Reynolds-averaged Navier–Stokes based on the experimental validation. Good agreement indicates that the method of large eddy simulation could be applied in the simulation of pump–turbines. Then, a detailed comparison of variation for peak-to-peak value in the whole passage was presented. Both the methods show that the highest level pressure fluctuations occur in the vaneless space. In addition, the propagation of amplitudes of blade pass frequency, 2 times of blade pass frequency, and 3 times of blade pass frequency in the circumferential and flow directions was investigated. Although the difference exists between large eddy simulation and unsteady Reynolds-averaged Navier–Stokes, the trend of variation in different parts is almost the same. Based on the analysis, using the same mesh (8 million, large eddy simulation underestimates pressure characteristics and shows a better result compared with the experiments, while unsteady Reynolds-averaged Navier–Stokes overestimates them.

Floating wind turbine system

Science.gov (United States)

Viterna, Larry A. (Inventor)

2009-01-01

A floating wind turbine system with a tower structure that includes at least one stability arm extending therefrom and that is anchored to the sea floor with a rotatable position retention device that facilitates deep water installations. Variable buoyancy for the wind turbine system is provided by buoyancy chambers that are integral to the tower itself as well as the stability arm. Pumps are included for adjusting the buoyancy as an aid in system transport, installation, repair and removal. The wind turbine rotor is located downwind of the tower structure to allow the wind turbine to follow the wind direction without an active yaw drive system. The support tower and stability arm structure is designed to balance tension in the tether with buoyancy, gravity and wind forces in such a way that the top of the support tower leans downwind, providing a large clearance between the support tower and the rotor blade tips. This large clearance facilitates the use of articulated rotor hubs to reduced damaging structural dynamic loads. Major components of the turbine can be assembled at the shore and transported to an offshore installation site.

Wind pumps for farms: Economic and environmental feasibility

International Nuclear Information System (INIS)

Piccoli, F.

1992-01-01

The cost and environmental benefits of four different types of water pumps for use on farms are compared. The factors considered in the analysis of the different pumps categorized according to head (7, 30 and 50 m) and energy source (wind energy, electricity, gasoline or fuel oil) include operating and maintenance costs, and payback periods. Particular attention is given to the socio-economic implications of the use of wind pumps in developing countries. In this case, the various aspects taken into account are: wind pump siting requirements, optimum sizing, the feasibility of water pumping-power production with the use of wind turbines, required skill levels of operators, and environmental compatibility

Reactor coolant pumps for nuclear reactors

International Nuclear Information System (INIS)

Harand, E.; Richter, G.; Tschoepel, G.

1975-01-01

A brake for the pump rotor of a main coolant pump or a shutoff member on the pump are provided in order to prevent excess speeds of the pump rotor. Such excess speeds may occur in PWR type reactors with water at a pressure below, e.g., 150 bars if there is leakage from a coolant line associated with the main coolant pump. As a brake, a centrifugal brake depending upon the pump speed or a brake ring arranged on the pump housing and acting on the pump rotor, which ring would be activated by pressure differentials in the pump, may be used. If the pressure differences between suction and pressure sockets are very small, a controlled hydraulic increase of the pressure force on the brake may also be provided. Furthermore, a turbine brake may be provided. A slide which is automatically movable in closing position along the pump rotor axis is used as a shutoff element. It is of cylindrical configuration and is arranged concentrically with the rotor axis. (DG) [de

Repair of Kaplan turbine shaft sealing based on evaluation of hydraulic conditions

International Nuclear Information System (INIS)

Lakatos, K; Szamosi, Z; Bereczkei, S

2012-01-01

This paper has been written to call attention to a potential danger what may occur in Kaplan turbine refurbishments. In Tiszalök hydropower plant, Hungary, the shaft sealing of the refurbished turbine was damaged. In searching for the reasons it was assumed that due to increased internal velocities in the turbine, the pressure at the hub clearance became lower than the atmospheric pressure, and therefore the sealing, which always operated satisfactorily before the refurbishment, had uncertain water supply, dry-running occurred, and after some time the sealing was burnt. First the flow conditions in the turbine and the pressure at the hub clearance were calculated by a one-dimensional flow model. Later this was refined by a two-dimensional approach. The above conclusion was also justified by the data acquisition system and by observing the operation of the small dewatering pump. When the turbine operated at a larger discharge than a certain limit value, then the dewatering pump remained standstill, indicating that no water passed through the shaft sealing. External water supply was then applied, and after this the turbine operated all right.

Repair of Kaplan turbine shaft sealing based on evaluation of hydraulic conditions

Science.gov (United States)

Lakatos, K.; Szamosi, Z.; Bereczkei, S.

2012-11-01

This paper has been written to call attention to a potential danger what may occur in Kaplan turbine refurbishments. In Tiszalök hydropower plant, Hungary, the shaft sealing of the refurbished turbine was damaged. In searching for the reasons it was assumed that due to increased internal velocities in the turbine, the pressure at the hub clearance became lower than the atmospheric pressure, and therefore the sealing, which always operated satisfactorily before the refurbishment, had uncertain water supply, dry-running occurred, and after some time the sealing was burnt. First the flow conditions in the turbine and the pressure at the hub clearance were calculated by a one-dimensional flow model. Later this was refined by a two-dimensional approach. The above conclusion was also justified by the data acquisition system and by observing the operation of the small dewatering pump. When the turbine operated at a larger discharge than a certain limit value, then the dewatering pump remained standstill, indicating that no water passed through the shaft sealing. External water supply was then applied, and after this the turbine operated all right.

Turbines for nuclear power plants. 2.ed.

International Nuclear Information System (INIS)

Troyanovskij, B.M.

1978-01-01

In the second edition of the book considered are practically all the main problems of calculation and operation of turbines and turbine installations of nuclear power plants. As compared to the first edition, essentially addes is the reproduction of the problem on combined generation of heat and electric energy. Also represented is detailed material on methods of preliminary evaluation of turbine effectiveness. Considered are peculiarities of turbine operation on wet steam and the basis of their thermal calculation. Much attention is payed to the problem of wet stream current in the turbine elements and wetness effect on their characteristics. Problems of wetness separation and moving blade erosion as well as other turbine elements are extracted in a special section. Given are structural schemes of different methods of innerchannel and periphery wet removal as well as experimental materials on their effectiveness. Given are descriptions and critical analysis of a great number of typical constructions of nuclear power plant steam turbines, produced by native plants as well as by the main foreign firms. Considered also are constructions of outside separators and steam superheaters. Separately given is the problem of rotation frequency choise of nuclear power plant wet steam turbines. Represented are materials on turbine installation tests, considered are the problems of turbine starting and manoeuvrability, analyzed are their typical jailures and damages. One of the sections of the book is devoted to gas turbine installations of nuclear power plants. Different material on this theme scattered before in various sources is summarized in the book

Preliminary assessment of the Velocity Pump Reaction Turbine as a geothermal total-flow expander

Energy Technology Data Exchange (ETDEWEB)

Demuth, O.J.

1985-01-01

A preliminary evaluation was made of the Velocity Pump Reaction Turbine (VPRT) as a total flow expander in a geothermal-electric conversion cycle. Values of geofluid effectiveness of VPRT systems were estimated for conditions consisting of: a 360/sup 0/F geothermal resource, 60/sup 0/F wet-bulb ambient temperature, zero and 0.003 mass concentrations of dissolved noncondensible gas in the geofluid, 100 and 120/sup 0/F condensing temperature, and engine efficiencies ranging from 0.4 to 1.0. Achievable engine efficiencies were estimated to range from 0.47 to 0.77, with plant geofluid effectivenss values ranging as high as 9.5 Watt hr/lbm geofluid. This value is competitive with magnitudes of geofluid effectiveness projected for advanced binary plants, and is on the order of 40% higher than estimates for dual-flash steam systems and other total flow systems reviewed. Because of its potentially high performance and relative simplicity, the VPRT system appears to warrant further investigation toward its use in a well-head geothermal plant. 13 refs., 5 figs.

Test specification for decant pump and winch assembly

International Nuclear Information System (INIS)

Staehr, T.W.

1994-01-01

This specification provides the requirements for testing of the vertical turbine decant pump including the floating suction arm with load sensing winch control, instrumentation and the associated PLC/PC control system

CFD research on runaway transient of pumped storage power station caused by pumping power failure

International Nuclear Information System (INIS)

Zhang, L G; Zhou, D Q

2013-01-01

To study runaway transient of pumped storage power station caused by pumping power failure, three dimensional unsteady numerical simulations were executed on geometrical model of the whole flow system. Through numerical calculation, the changeable flow configuration and variation law of some parameters such as unit rotate speed,flow rate and static pressure of measurement points were obtained and compared with experimental data. Numerical results show that runaway speed agrees well with experimental date and its error was 3.7%. The unit undergoes pump condition, brake condition, turbine condition and runaway condition with flow characteristic changing violently. In runaway condition, static pressure in passage pulses very strongly which frequency is related to runaway speed

Study on the application of energy storage system in offshore wind turbine with hydraulic transmission

International Nuclear Information System (INIS)

Fan, Yajun; Mu, Anle; Ma, Tao

2016-01-01

Highlights: • Hydraulic offshore wind turbine is capable of outputting near constant power. • Open loop hydraulic transmission uses seawater as the working fluid. • Linear control strategy distributes total flow according to demand and supply. • Constant pressure hydraulic accumulator stores/releases the surplus energy. • Simulations show the dynamic performance of the hybrid system. - Abstract: A novel offshore wind turbine comprising fluid power transmission and energy storage system is proposed. In this wind turbine, the conventional mechanical transmission is replaced by an open-loop hydraulic system, in which seawater is sucked through a variable displacement pump in nacelle connected directly with the rotor and utilized to drive a Pelton turbine installed on the floating platform. Aiming to smooth and stabilize the output power, an energy storage system with the capability of flexible charging and discharging is applied. The related mathematical model is developed, which contains some sub-models that are categorized as the wind turbine rotor, hydraulic pump, transmission pipeline, proportional valve, accumulator and hydraulic turbine. A linear control strategy is adopted to distribute the flow out of the proportional valve through comparing the demand power with captured wind energy by hydraulic pump. Ultimately, two time domain simulations demonstrate the operation of the hybrid system when the hydraulic accumulator is utilized and show how this system can be used for load leveling and stabilizing the output power.

Solving optimum operation of single pump unit problem with ant colony optimization (ACO) algorithm

International Nuclear Information System (INIS)

Yuan, Y; Liu, C

2012-01-01

For pumping stations, the effective scheduling of daily pump operations from solutions to the optimum design operation problem is one of the greatest potential areas for energy cost-savings, there are some difficulties in solving this problem with traditional optimization methods due to the multimodality of the solution region. In this case, an ACO model for optimum operation of pumping unit is proposed and the solution method by ants searching is presented by rationally setting the object function and constrained conditions. A weighted directed graph was constructed and feasible solutions may be found by iteratively searching of artificial ants, and then the optimal solution can be obtained by applying the rule of state transition and the pheromone updating. An example calculation was conducted and the minimum cost was found as 4.9979. The result of ant colony algorithm was compared with the result from dynamic programming or evolutionary solving method in commercial software under the same discrete condition. The result of ACO is better and the computing time is shorter which indicates that ACO algorithm can provide a high application value to the field of optimal operation of pumping stations and related fields.

The effectiveness of absorption heat pumps application for the increase of economic efficiency of CHP operation

Directory of Open Access Journals (Sweden)

Luzhkovoy Dmitriy S.

2017-01-01

Full Text Available The article deals with a comparative analysis of CHP operational efficiency in various working modes before and after the absorption heat pumps installation. The calculation was performed using a mathematical model of the extraction turbine PT- 80/100-130/13. Absorption heat pumps of LLC “OKB Teplosibmash” were used as AHP models for the analysis. The most effective way of absorption lithium-bromide heat pumps application as a part of the turbine PT-80/100-130/13 turned out to be their usage in a heat-producing mode during a non-heating season with a load of hot water supply. For this mode the dependence of the turbine heat efficiency on the heat load of the external consumer at a given throttle flow was analyzed.

Pumped energy transfer stations (STEP)

International Nuclear Information System (INIS)

Tournery, Jean-Francois

2015-12-01

As objectives of development are high for renewable energies (they are supposed to cover 50 per cent of new energy needs by 2035), pumped energy transfer stations are to play an important role in this respect. The author first discusses the consequences of the development of renewable energies on the exploitation of electric grids: issue of intermittency for some of them, envisaged solutions. Then, he addresses one of the solutions: the storage of electric power. He notices that increasing the potential energy of a volume of water is presently the most mature solution to face massive needs of the power system. Dams and pumped energy transfer stations represent now almost the whole installed storage power in the world. The author then presents these pumped energy transfer stations: principle, brief history (the first appeared in Italy and Switzerland at the end of the 1890's). He indicates the various parameters of assessment of such stations: maximum stored energy, installed power in pumping mode and turbine mode, time constant, efficiency, level of flexibility. He discusses economic issues. He describes and comments the operation of turbine-pump groups: ternary groups, reversible binary groups. He discusses barriers to be overcome and technical advances to be made for varying speed groups and for marine stations. He finally gives an overview (table with number of stations belonging to different power ranges, remarkable installations) of existing stations in China, USA, Japan, Germany, Austria, Spain, Portugal, Italy, Switzerland, France and UK, and indicate predictions regarding storage needs at the world level. Some data are finally indicated for the six existing French installations

Modeling and control of a hybrid wind-tidal turbine with hydraulic accumulator

International Nuclear Information System (INIS)

Fan, YaJun; Mu, AnLe; Ma, Tao

2016-01-01

This paper presents the modeling and control of a hybrid wind-tidal turbine with hydraulic accumulator. The hybrid turbine captures the offshore wind energy and tidal current energy simultaneously and stores the excess energy in hydraulic accumulator prior to electricity generation. Two hydraulic pumps installed respectively in wind and tidal turbine nacelles are used to transform the captured mechanical energy into hydraulic energy. To extract the maximal power from wind and tidal current, standard torque controls are achieved by regulating the displacements of the hydraulic pumps. To meet the output power demand, a Proportion Integration Differentiation (PID) controller is designed to distribute the hydraulic energy between the accumulator and the Pelton turbine. A simulation case study based on combining a 5 MW offshore wind turbine and a 1 MW tidal current turbine is undertaken. Case study demonstrates that the hybrid generation system not only captures all the available wind and tidal energy and also delivers the desired generator power precisely through the accumulator damping out all the power fluctuations from the wind and tidal speed disturbances. Energy and exergy analyses show that the energy efficiency can exceed 100% as the small input speeds are considered, and the exergy efficiency has the consistent change trends with demand power. Further more parametric sensitivity study on hydraulic accumulator shows that there is an inversely proportional relationship between accumulator and hydraulic equipments including the pump and nozzle in terms of dimensions. - Highlights: • A hybrid wind-tidal turbine is presented. • Hydraulic accumulator stores/releases the surplus energy. • Standard torque controls extract the maximal power from wind and tidal. • Generator outputs meet the electricity demand precisely. • Parametric sensitivity study on accumulator is implemented.

Modernization of the turbine control technique and the turbine hydraulics aimed to improved maneuverability in the load range, system safety and plant availability, plant transparency for diagnosis and long-term performance

International Nuclear Information System (INIS)

Baran, Detlef

2012-01-01

In the contribution H.Mauell GmbH presents modernization projects for the nuclear power plants Tihange-3 and Doel-4. The project volume included control technique and the turbine hydraulics for the steam turbo generating set including turbine auxiliary devices and two turbine feeding pumps. The modernizations were successfully completed in 2010 and 2011, respectively. The nuclear power plants are trouble-free operated.

Development of liquid nitrogen Centrifugal Pump

International Nuclear Information System (INIS)

Abe, M; Sagiyama, R; Tsuchiya, H; Takayama, T; Torii, Y; Nakamura, M; Hoshino, Y; Odashima, Y

2009-01-01

Usually liquid nitrogen (LN 2 ) transfer from a container to a laboratory equipment takes place by applying pressure to the container to push out liquid or pouring liquid into the cryostat directly by lifting the container. In order to overcome inconvenience of pressuring or lifting containers, we have been developing the Liquid Nitrogen Centrifugal Pump of a small electric turbine pump. Significant advantages that both reducing time to fill LN 2 and controlling the flow rate of liquid into the cryostat are obtained by introducing this pump. We have achieved the lift of about 800mm with the vessel's opening diameter of 28mm.

Migration of bats past a remote island offers clues toward the problem of bat fatalities at wind turbines

Science.gov (United States)

Cryan, P.M.; Brown, A.C.

2007-01-01

Wind energy is rapidly becoming a viable source of alternative energy, but wind turbines are killing bats in many areas of North America. Most of the bats killed by turbines thus far have been migratory species that roost in trees throughout the year, and the highest fatality events appear to coincide with autumn migration. Hoary bats (Lasiurus cinereus) are highly migratory and one of the most frequently killed species at wind turbines. We analyzed a long-term data set to investigate how weather and moonlight influenced the occurrence of hoary bats at an island stopover point along their migration route. We then related our results to the problem of bat fatalities at wind turbines. We found that relatively low wind speeds, low moon illumination, and relatively high degrees of cloud cover were important predictors of bat arrivals and departures, and that low barometric pressure was an additional variable that helped predict arrivals. Slight differences in the conditions under which bats arrived and departed from the island suggest that hoary bats may be more likely to arrive on the island with passing storm fronts in autumn. These results also indicate that fatalities of hoary bats at wind turbines may be predictable events, that the species may be drawn to prominent landmarks that they see during migration, and that they regularly migrate over the ocean. Additional observations from this and other studies suggest that the problem of bat fatalities at wind turbines may be associated with flocking and autumn mating behaviors.

Axial turbine with underwater generator for energy recovery; Axialturbine mit Unterwassergenerator zur Energierueckgewinnung

Energy Technology Data Exchange (ETDEWEB)

Welzel, B. [Stuttgart Univ. (Germany). Inst. fuer Stroemungsmechanik und Hydraulische Stroemungsmaschinen

1997-12-31

Within the framework of a project sponsored by the Stiftung Energieforschung Baden-Wuerttemberg, an axial turbine was developed as a flash evaporator, which permits energy recovery in all sectors where liquids in piping undergoes pressure relaxation. A specific feature of this turbine is that it forms part, complete with generator, of a single pipeline and that it does not cause any pressure variations worth mentioning in case of mains failure. The report describes the turbine, its advantages, and a pilot operation carried out with a prototype. The turbine`s performance is compared with a return pump. Further, the optimization of the hydraulic design by computer and the results of a market analysis are dealt with. (orig.) [Deutsch] Im Rahmen einer von der Stiftung Energieforschung Baden-Wuerttemberg gefoerderten Neuentwicklung wurde eine Axialturbine als Entspannungsturbine entwickelt, mit der eine Energierueckgewinnung in allen Bereichen erfolgen kann, in denen Fluessigkeiten in Rohrleitungssystemen entspannt werden. Die Turbine zeichnet sich unter anderem dadurch aus, dass sie komplett, inklusive Generator, innerhalb einer Rohrleitung angeordnet ist und bei Netzausfall keine nennenswerte Druckschwankung erzeugt. Es werden die Turbine, deren Vorteile sowie der mit einem Prototypen durchgefuehrte Betriebsversuch beschrieben. Weiterhin werden ein Vergleich des Betriebsverhaltens mit einer rueckwaertslaufenden Pumpe, die rechnerische Optimierung der hydraulischen Formgebung sowie die Ergebnisse einer Marktanalyse behandelt. (orig.)

O?shore ?oating wind turbine and its dynamic problems?

Institute of Scientific and Technical Information of China (English)

Renchuan ZHU; Guoping MIAO; Ju FAN; Hua LIU

2016-01-01

Green energy sources and ocean wind power are plentiful in deep sea. More and more o?shore wind power plants are constructed in the deep water over hundred meters below the surface. While o?shore ?oating wind turbine system is working, wind turbine, ?oating foundation, and mooring system a?ect each other with wind, waves, and currents acting on them. Various o?shore ?oating wind turbine systems and the encoun-tered environmental loads are brie?y reviewed and discussed. It is di?cult and crucial to comprehensively analyze the aerodynamic-hydrodynamic-service system-structure un-der the coupling e?ect of o?shore ?oating wind turbine system. The environmental ?ow ?eld, structure scale, and rational applications of theories and approaches should be well considered in advance.

The analysis of Drug - Related Problems in patients with gastroesophageal reflux disease treated with proton-pump inhibitors

Directory of Open Access Journals (Sweden)

Milutinović Jelena D.

2015-01-01

Full Text Available Introduction: Drug-related problems are frequent in almost all therapeutic areas. Aims: The aim of this paper was to detect drug - related problems in patients with gastroesophageal reflux and to analyze their possible association with the patient characteristics. Material and methods: The study was designed as descriptive, retrospective, crosssectional study aiming to determine the most common drug - related problems in patients with gastro-esophageal reflux disease treated with proton-pump inhibitors. The survey was conducted at the Department of Gastroenterology, Clinical Centre in Kragujevac. The study enrolled all patients treated from gastroesophageal reflux disease with proton pump inhibitors during the time period from 1.1.2014 until 1.1.2015. The study used descriptive statistics (percentage distribution, mean and standard deviation. The correlation between the number of adverse events and patient characteristics was also calculated. Results: The average age of the patients was 55.97±15.811 years, and 43 of the patients (60.6 % were male. The average hospitalization duration was 12.30±8.89 days. Based on the Pharmaceutical Care Network Europe classification, there were 182 Drug-Related Problems which was, on average, 2.56 problems per patient. Only 5 patients (7% did not report any problem while 11 patients (15.49% had over 10 possible drug-drug interactions. The most common problems which occurred were erroneous drug choice, inappropriate administration and possible interactions between medications. Conclusions: Based on the results of this study, one must pay attention to possible drug interactions and other problems which may occur with proton-pump inhibitors. Recognition of different sub-types of drug-related problems and of factors associated with drug related problems may reduce risk from adverse outcomes of gastro-esophageal reflux disease treatment with proton pump inhibitors.

Aggregated Control of Domestic Heat Pumps

DEFF Research Database (Denmark)

Nielsen, Kirsten M.; Andersen, Palle; Pedersen, Tom S.

2013-01-01

A challenge in Denmark in the near future is to balance the electrical grid due to a large increase in the renewable energy production mainly from wind turbines. In this work an aggregated control system using heat pumps in single family houses to help balancing the grid is investigated....... The control system is able to adjust the consumptions of the heat pump without affecting the comfort in the houses and uses this ability to shift the total consumption to hours with high wind energy production....

Pumping behavior of sputter ion pumps

International Nuclear Information System (INIS)

Chou, T.S.; McCafferty, D.

The ultrahigh vacuum requirements of ISABELLE is obtained by distributed pumping stations. Each pumping station consists of 1000 l/s titanium sublimation pump for active gases (N 2 , H 2 , O 2 , CO, etc.), and a 20 l/s sputter ion pump for inert gases (methane, noble gases like He, etc.). The combination of the alarming production rate of methane from titanium sublimation pumps (TSP) and the decreasing pumping speed of sputter ion pumps (SIP) in the ultrahigh vacuum region (UHV) leads us to investigate this problem. In this paper, we first describe the essential physics and chemistry of the SIP in a very clean condition, followed by a discussion of our measuring techniques. Finally measured methane, argon and helium pumping speeds are presented for three different ion pumps in the range of 10 -6 to 10 -11 Torr. The virtues of the best pump are also discussed

A Laminar Flow-Based Microfluidic Tesla Pump via Lithography Enabled 3D Printing

Directory of Open Access Journals (Sweden)

Mohammed-Baker Habhab

2016-11-01

Full Text Available Tesla turbine and its applications in power generation and fluid flow were demonstrated by Nicholas Tesla in 1913. However, its real-world implementations were limited by the difficulty to maintain laminar flow between rotor disks, transient efficiencies during rotor acceleration, and the lack of other applications that fully utilize the continuous flow outputs. All of the aforementioned limits of Tesla turbines can be addressed by scaling to the microfluidic flow regime. Demonstrated here is a microscale Tesla pump designed and fabricated using a Digital Light Processing (DLP based 3D printer with 43 µm lateral and 30 µm thickness resolutions. The miniaturized pump is characterized by low Reynolds number of 1000 and a flow rate of up to 12.6 mL/min at 1200 rpm, unloaded. It is capable of driving a mixer network to generate microfluidic gradient. The continuous, laminar flow from Tesla turbines is well-suited to the needs of flow-sensitive microfluidics, where the integrated pump will enable numerous compact lab-on-a-chip applications.

A Laminar Flow-Based Microfluidic Tesla Pump via Lithography Enabled 3D Printing.

Science.gov (United States)

Habhab, Mohammed-Baker; Ismail, Tania; Lo, Joe Fujiou

2016-11-23

Tesla turbine and its applications in power generation and fluid flow were demonstrated by Nicholas Tesla in 1913. However, its real-world implementations were limited by the difficulty to maintain laminar flow between rotor disks, transient efficiencies during rotor acceleration, and the lack of other applications that fully utilize the continuous flow outputs. All of the aforementioned limits of Tesla turbines can be addressed by scaling to the microfluidic flow regime. Demonstrated here is a microscale Tesla pump designed and fabricated using a Digital Light Processing (DLP) based 3D printer with 43 µm lateral and 30 µm thickness resolutions. The miniaturized pump is characterized by low Reynolds number of 1000 and a flow rate of up to 12.6 mL/min at 1200 rpm, unloaded. It is capable of driving a mixer network to generate microfluidic gradient. The continuous, laminar flow from Tesla turbines is well-suited to the needs of flow-sensitive microfluidics, where the integrated pump will enable numerous compact lab-on-a-chip applications.

Problems of steam turbine diagnostics and the 'Simens' diagnosis system

International Nuclear Information System (INIS)

Tserner, V.; Andrea, K.

1993-01-01

Diagnostics system, allowing one to detect changes in the state on single turbine elements at an early stage is described. Besides this system allows one to utilize the turbine plant optimally and efficiency from the viewpoint of the equipment durability. Specially oriented monitoring of the turbine plant and equipment element state saves resources necessary to keep up the working order of the equipment

Studies of the impact of prerotation problem of the secondary impeller on performance of multi-stage centrifugal pumps

International Nuclear Information System (INIS)

Zhai, L L; Wu, P; Jiang, Q L; Wang, L Q

2012-01-01

In engineering practice, part of the multi-stage centrifugal pumps is designed without space guide vanes due to the size restrictions and the volute is distorted much in shape. In these pumps, tangential velocity of the fluid at the outlet of the first-stage impeller is so great that it has caused a prerotation problem which will affect the inlet flow conditions of the secondary impeller leading to serious efficiency and head decline of the secondary impeller. The head problem of the second stage in multi-stage centrifugal pumps caused by prerotation at the entrance of the second stage was analyzed and the internal hydraulic performance was optimized by setting clapboards in the volute in this paper. CFD numerical simulation method combined with experiment was applied to predict the effect of internal clapboards on the performance of the centrifugal pump. The original prototype was transformed according to the simulation result and tested to verify the optimization work. The experiment result shows that hydraulic performance is remarkably improved compared with the original one and the prerotation problem is basically solved.

Pumped storage hydroelectric power plant Cierny Vah

International Nuclear Information System (INIS)

2006-01-01

are sealed by a bituminous and cement coat. In a footing of the reservoir along its perimeter there is a tunnel for leakage water controlling. The utilizable reservoir volume represents 3,7 mil m 3 and operating levels fluctuate by 25 m between the elevations 1.160 and 1.135 m above sea level. An inflow object is incorporated into the perimeter of a dam for three intake pipes and the communication tunnel exit with an inclined lift. An approach from Svarin is 7,5 km long utilizing the former forest roads. The hydro power plant is a body part of the lower reservoir. In it there are six vertical pumping aggregates in the three machine layout: the motor-generator - the turbine - the pump. Between the turbine and the pump there is a hydraulic controlled claw clutch engaging at rest and disengaging also during the aggregate operation. During pumping air is involved inside the turbine. The Francis turbines have the diameter of a runner 2.600 mm. The pumps are single-inlet, two-stage. In 1985 the originally installed capacity 6 x 111.6 MW was increased in absorption capacity of the turbine to 6 x 122,4 MW after verification and tests by a supplier of technology. A Kaplan turbine TG7 set with installed capacity 0,768 MW and absorption capacity from 4,5 to 8 m 3 .s -1 is installed for performing the natural flows of Cierny Vah in a building of the hydro power plant. The lower reservoir with relaying of the road. The dam of the lower reservoir into which the building of the hydro-plant is included is concrete, gravitational. There is a levee on the aerial side for implanting greens and thus including it into surroundings. The side slopes have a filtration layer of a Tatratex geofabric, they have their inclination 1:5, and are protected by aggregates. The utilizable reservoir volume is 3,7 mil m3 in level fluctuation 7,45 m between the elevations 733,45 - 726,0 m above sea level

New low pressure (LP) turbines for NE Krsko

International Nuclear Information System (INIS)

Nemcic, K.; Novsak, M.

2004-01-01

During the evaluation of possible future maintenance strategies on steam turbine in very short period of time, engineering decision was made by NE Krsko in agreement with Owners to replace the existing two Low Pressure (LP) Turbines with new upgrading LP Turbines. This decision is presented with review of the various steam turbine problems as: SCC on turbine discs; blades cracking; erosion-corrosion with comparison of various maintenance options and efforts undertaken by the NE Krsko to improve performance of the original low pressure turbines. This paper presents the NEK approach to solve the possible future problems with steam turbine operation in NE Krsko as pro-active engineering and maintenance activities on the steam turbine. This paper also presents improvements involving retrofits, confined to the main steam turbine path, with major differences between original and new LP Turbines as beneficial replacement because of turbine MWe upgrading and return capital expenditures.(author)

PUMPED STORAGE ENVIRONMENTAL EFFECTS: ASSESSMENT OF RESEARCH NEEDS

Energy Technology Data Exchange (ETDEWEB)

DH. Fickeisen

1979-09-01

Pumped storage hydroelectric systems convert large quantities of electrical energy to a form that may be stored and efficiently reconverted to electricity. Water is pumped from a lower reservoir to an upper reservoir during periods of low power demand. The stored water is then used to generate additional power when demand peaks. Since the basic requirements of the system are simple, the design of individual plants and their locations vary widely. These variations make assessment of the generic environmental impact of the pumped storage systems difficult. In addition, most studies have not examined the impacts of an operating plant comprehensively. Assessment of the environmental effects of development and operation of a pumped storage plant requires an extensive set of baseline information, which is deficient in several aspects at the present state of the art. Additional research is needed to: • identify species groups likely to survive and reproduce in pumped storage reservoirs, their relationships and habitat preferences, and the basis for their production; • characterize anticipated reservoir ecosystem community development and relate it to physical characteristics of pumped storage reservoirs; • define effects of plant design and operating parameters on transport of organisms through the pump/turbine facility, accounting for behavior of the organisms potentially impacted; • access the mortality rate of organisms likely to pass through pump-turbines; • identify the relative advantages and disadvantages of screening intake structures to prevent passage of large organisms through the plant; • assess the effects of currents and water withdrawal on migration and movement of aquatic species; • investigate the effects of fluctuating water levels on the littoral zone and riparian communities, effects of stranding on entrapment of fishes, and effects on fish spawning; and • review the applicability of water quality and ecosystem models to pumped storage

Effects of gain-scheduling methods in a classical wind turbine controller on wind turbine aeroservoelastic modes and loads

DEFF Research Database (Denmark)

Tibaldi, Carlo; Henriksen, Lars Christian; Hansen, Morten Hartvig

2014-01-01

The eects of dierent gain-scheduling methods for a classical wind turbine controller, operating in full load region, on the wind turbine aeroservoelastic modes and loads are investigated in this work. The dierent techniques are derived looking at the physical problem to take into account the chan......The eects of dierent gain-scheduling methods for a classical wind turbine controller, operating in full load region, on the wind turbine aeroservoelastic modes and loads are investigated in this work. The dierent techniques are derived looking at the physical problem to take into account...

Large nuclear steam turbine plants

International Nuclear Information System (INIS)

Urushidani, Haruo; Moriya, Shin-ichi; Tsuji, Kunio; Fujita, Isao; Ebata, Sakae; Nagai, Yoji.

1986-01-01

The technical development of the large capacity steam turbines for ABWR plants was partially completed, and that in progress is expected to be completed soon. In this report, the outline of those new technologies is described. As the technologies for increasing the capacity and heightening the efficiency, 52 in long blades and moisture separating heaters are explained. Besides, in the large bore butterfly valves developed for making the layout compact, the effect of thermal efficiency rise due to the reduction of pressure loss can be expected. As the new technology on the system side, the simplification of the turbine system and the effect of heightening the thermal efficiency by high pressure and low pressure drain pumping-up method based on the recent improvement of feed water quality are discussed. As for nuclear steam turbines, the actual records of performance of 1100 MW class, the largest output at present, have been obtained, and as a next large capacity machine, the development of a steam turbine of 1300 MWe class for an ABWR plant is in progress. It can be expected that by the introduction of those new technologies, the plants having high economical efficiency are realized. (Kako, I.)

Theoretical Investigation For The Effect of Fuel Quality on Gas Turbine Power Plants

Science.gov (United States)

AbdulRazzak khudair, Omar; Alwan Abass, Khetam; Saadi Abed, Noor; Hussain Ali, Khalid; AbdulAziz, Saad; Chlaib Shaboot, Ali

2018-05-01

Gas turbine engine power generation is declined dramatically because of the reduction in thermodynamic parameters as a work of turbine, compressor ratio, compressor work, and air mass flow rate and fuel consumption. There are two main objectives of this work, the first is related with the effect of fuel kinds and their quality on the operation of fuel flow divider and its performance specifically gear pump displacement and fuel flow rate to the combustion chambers of gas power plant. AL-DORA gas turbine power plant 35MW was chosen to predict these effects on its performance MATLAB Software program is used to perform thermodynamic calculations. Fuel distribution stage before the process of combustion and as a result of the kind and its quality, chemical reaction will occur between the fuel and the parts of the gear system of each pump of the flow divider, which causes the erosion of the internal pump wall and the teeth of the gear system, thus hampering the pump operation in terms of fuel discharge. The discharge of fuel form the eight external gates of flow divider is decreased and varied when going to the combustion chambers, so that, flow divider does not give reliable mass flow rate due to absence of accurate pressure in each of eight exit pipes. The second objective deals with the stage of fuel combustion process inside the combustion chamber. A comparative study based upon performance parameters, such as specific fuel consumption for gas and gasoil and power generation. Fuel poor quality causes incomplete combustion and increased its consumption, so that combustion products are interacted with the surface of the turbine blades, causing the erosion and create surface roughness of the blade and disruption of gas flow. As a result of this situation, turbulence flow of these gases will increase causing the separation of gas boundary layers over the suction surface of the blade. Therefore the amount of extracted gas will decrease causing retreat work done by

Optimization of hybrid system (wind-solar energy) for pumping water

African Journals Online (AJOL)

DR OKE

Keywords: Renewable energy; pumping water; technical optimization; ... The country already start on a mega-project of solar power production (2000 MW) ...... with a wind turbine in a standalone renewable energy system based on hydrogen.

Variable Pitch Darrieus Water Turbines

Science.gov (United States)

Kirke, Brian; Lazauskas, Leo

In recent years the Darrieus wind turbine concept has been adapted for use in water, either as a hydrokinetic turbine converting the kinetic energy of a moving fluid in open flow like an underwater wind turbine, or in a low head or ducted arrangement where flow is confined, streamtube expansion is controlled and efficiency is not subject to the Betz limit. Conventional fixed pitch Darrieus turbines suffer from two drawbacks, (i) low starting torque and (ii) shaking due to cyclical variations in blade angle of attack. Ventilation and cavitation can also cause problems in water turbines when blade velocities are high. Shaking can be largely overcome by the use of helical blades, but these do not produce large starting torque. Variable pitch can produce high starting torque and high efficiency, and by suitable choice of pitch regime, shaking can be minimized but not entirely eliminated. Ventilation can be prevented by avoiding operation close to a free surface, and cavitation can be prevented by limiting blade velocities. This paper summarizes recent developments in Darrieus water turbines, some problems and some possible solutions.

Geothermal pump down-hole energy regeneration system

Science.gov (United States)

Matthews, Hugh B.

1982-01-01

Geothermal deep well energy extraction apparatus is provided of the general kind in which solute-bearing hot water is pumped to the earth's surface from a subterranean location by utilizing thermal energy extracted from the hot water for operating a turbine motor for driving an electrical power generator at the earth 3 s surface, the solute bearing water being returned into the earth by a reinjection well. Efficiency of operation of the total system is increased by an arrangement of coaxial conduits for greatly reducing the flow of heat from the rising brine into the rising exhaust of the down-well turbine motor.

Reactor feedwater pump control device

International Nuclear Information System (INIS)

Nishiyama, Hiroyuki.

1990-01-01

An amount of feedwater necessary for ensuring reactor inventory after scram is ensured automatically based on the reactor output before scram of a BWR type reactor. That is, if scram should occur, a feedwater flow rate just before the scram is stored by reactor output signals. Further, the amount of feedwater required after the scram is determined based on the output of the memory. The reactor power after the scram based on a feedwater flow rate and a main steam flow rate is inputted to an integrator, to calculate and output the amount of the feedwater flow rate (1) injected after the scram for the inventory. A coast down flowrate (2) in a case of pump trip is forecast by the output signals. Automatic trip is outputted to all turbine driving feedwater pumps when the sum of (1) and (2) exceeds a necessary and sufficient amount of feedwater required for ensuring inventory. For motor driving feedwater pumps, only a portion, for example, one of the pumps is automatically started while other pumps are stopped their operation, only in this case, to prevent excess water feeding. (I.S.)

Control system for NPP powerfull turbines

International Nuclear Information System (INIS)

Osipenko, V.D.; Rozhanskij, V.E.; Rokhlenko, V.Yu.

1985-01-01

A control system for NPP 1000 MW turbines safety is described. The turbine safety system has a hydraulic drive to actuate in case of increasipg of rotational speed of a turbine rotor and an electrohydraulic drce to operate in case of pressure reduction in the lubrication system, axial displacement deviation, etc. The system is highly reliable due to application of a safety system without slide valves and long-term operation of hydraulic controls in guarding conditions; the system epsures multifunctional control with high accuracy and speed due to application of the intricate electronic part, high speed of response with a limited use of high pressure oil due to application of two-pressure pumps, pneumohydraulic accumulators and oil discharge valves. Steady-state serviceability of the system is maintained by devices for valve cooling dawn. A shockless change from electrohydraulic to hydraulic control channels is provided

Induction Motors Most Efficient Operation Points in Pumped Storage Systems

DEFF Research Database (Denmark)

Busca-Forcos, Andreea; Marinescu, Corneliu; Busca, Cristian

2015-01-01

A clear focus is nowadays on developing and improving the energy storage technologies. Pumped storage is a well-established one, and is capable of enhancing the integration of renewable energy sources. Pumped storage has an efficiency between 70-80%, and each of its elements affects it. Increased...... efficiency is desired especially when operating with renewable energy systems, which present low energy conversion factor (up to 50% - performance coefficient for wind turbines, and efficiency up to 40% for photovoltaic systems). In this paper the most efficient operation points of the induction motors...... in pumped storage systems are established. The variable speed operation of the pumped storage systems and motor loading conditions for pump applications have been the key factors for achieving the purpose of the paper....

Hydro-engineering structure and Liptovska Mara Pumped Storage Power Plant

International Nuclear Information System (INIS)

Regula, E.

2005-01-01

In this paper thirty years history of the Hydro-engineering structure and Liptovska Mara Pumped Storage Power Plant (PSPP) is presented. In 1975 year the Liptovska Mara PSPP was commissioned. There are 2 Kaplan turbines and 2 Derezias reversible turbines with a total installed power 198 MW. The average annual output is 134.5 GWh. As a part of this hydro-engineering structure is Besenova Small-scale power plants with 2 turbines and with installed power 4.64 MW. The average annual output consists 18.3 GWh. There up to end of 2004 year 3,620.172 MWh of electricity was produced. Environmental effects are discussed

Advanced Load Alleviation for Wind Turbines using Adaptive Trailing Edge Flaps: Sensoring and Control

DEFF Research Database (Denmark)

Andersen, Peter Bjørn

The purpose of wind turbines and their predecessors the windmill, is to convert the energy in the wind to usable energy forms. Whereas windmills of the past focused on the conversion of wind power to torque for grinding, pumping and winching, modern wind turbines convert the wind energy...... into electric power. They do so through incorporation of generators, which convert mechanical torque into electricity. Wind turbines are designed to keep the overall cost per produced Kilo Watt hour as low as possible. One way of improving the performance and lifetime of the wind turbine is through active flow...

Modal behavior of a reduced scale pump-turbine impeller. Part 1: Experiments

International Nuclear Information System (INIS)

Escaler, X; Huetter, J K; Egusquiza, E; Farhat, M; Avellan, F

2010-01-01

An experimental investigation has been carried out to quantify the effects of surrounding fluid on the modal behavior of a reduced scale pump-turbine impeller. The modal properties of the fluid-structure system have been obtained by Experimental Modal Analysis (EMA) with the impeller suspended in air and inside a water reservoir. The impeller has been excited with an instrumented hammer and the response has been measured by means of miniature accelerometers. The Frequency Response Functions (FRF's) have been obtained from a large number of impacting positions in order to ensure the identification of the main mode shapes. As a result, the main modes of vibration have been well characterized both in air and in water in terms of natural frequency, damping ratio and mode shape. The first mode is the 2 Nodal Diameter (ND), the second one is the 0ND and the following ones are the 3ND coupled with the 1ND. The visual observation of the animated mode shapes and the level of the Modal Assurance Criterion (MAC) have permitted to correlate the homologous modes of vibration of the fluid-structure system in air and in water. From this comparison the added mass effect on the natural frequencies and the fluid effect on the damping ratios have been quantified for the most significant modes. With the surrounding water, the natural frequencies decrease in average by 10%. On the other hand, the damping ratios increase in average by 0.5%. In any case, the damping ratio appears to decrease with the frequency value of the mode.

Design and field operation of 1175 MW steam turbine for Ohi Nuclear Power Station

International Nuclear Information System (INIS)

Hirota, Yoshio; Nakagami, Yasuo; Fujii, Hisashi; Shibanai, Hirooki.

1980-01-01

Two 1175 MW steam turbine and generator units have been successfully in commercial operation since March 1979 and December 1979 respectively at Ohi Nuclear Power Station of the Kansai Electric Power Company. Those units, the largest in their respective outputs in Japan, have also such remarkable design features as two-stage reheat, nozzle governing turbine, water cooled generator stator and turbine-driven feedwater pumps. This paper covers design features and some topics of various pre-operational tests of the above-mentioned units. (author)

Airfoil optimization for noise emission problem on small scale turbines

Energy Technology Data Exchange (ETDEWEB)

Gocmen, Tuhfe; Ozerdem, Baris [Mechanical Engineering Department, Yzmir Institute of Technology (Turkey)

2011-07-01

Wind power is a preferred natural resource and has had benefits for the energy industry and for the environment all over the world. However, noise emission from wind turbines is becoming a major concern today. This study paid close attention to small scale wind turbines close to urban areas and proposes an optimum number of six airfoils to address noise emission concerns and performance criteria. The optimization process aimed to decrease the noise emission levels and enhance the aerodynamic performance of a small scale wind turbine. This study determined the sources and the operating conditions of broadband noise emissions. A new design is presented which enhances aerodynamic performance and at the same time reduces airfoil self noise. It used popular aerodynamic functions and codes based on aero-acoustic empirical models. Through numerical computations and analyses, it is possible to derive useful improvements that can be made to commercial airfoils for small scale wind turbines.

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

Science.gov (United States)

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

2009-01-01

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.

In situ performance curves measurements of large pumps

International Nuclear Information System (INIS)

Anton, A

2010-01-01

The complex energetic system on the river Lotru in Romania comprises of a series of lakes and pumping stations and a major hydroelectric power plant: Lotru-Ciunget. All the efforts have been oriented towards the maintenance of the Pelton turbines and very little attention has been directed to the pumps. In the system, there are three large pumping stations and only in the last 5 years, the pump performances have become a concern. The performances where determined using portable ultrasonic flow meters, a Yates meter, precision manometers and appropriate electrical equipment for power measurement (Power Analiser - NORMA D4000 LEM). The measurements are not supposed to interfere with the normal operation so only a limited number of tests could be performed. Based on those tests, portions of the test curves have been measured and represented in specific diagrams.

In situ performance curves measurements of large pumps

Science.gov (United States)

Anton, A.

2010-08-01

The complex energetic system on the river Lotru in Romania comprises of a series of lakes and pumping stations and a major hydroelectric power plant: Lotru-Ciunget. All the efforts have been oriented towards the maintenance of the Pelton turbines and very little attention has been directed to the pumps. In the system, there are three large pumping stations and only in the last 5 years, the pump performances have become a concern. The performances where determined using portable ultrasonic flow meters, a Yates meter, precision manometers and appropriate electrical equipment for power measurement (Power Analiser - NORMA D4000 LEM). The measurements are not supposed to interfere with the normal operation so only a limited number of tests could be performed. Based on those tests, portions of the test curves have been measured and represented in specific diagrams.

The utilization of induction generators working with PATs (pumps working as turbines) in electric energy generation; A utilizacao de geradores de inducao acionados por BFTs (bombas funcionando como turbinas) na geracao de energia eletrica

Energy Technology Data Exchange (ETDEWEB)

Viana, Augusto Nelson Carvalho; Rezek, Angelo Jose Junqueira; Medeiros, Daniel de Macedo [Universidade Federal de Itajuba (UNIFEI), MG (Brazil). Programa de Pos-graduacao em Engenharia da Energia], e-mail: augusto@unifei.edu.br, e-mail: rezek@iee.efei.br, e-mail: macedo@unifei.edu.br

2004-07-01

The utilization of the Pumps working as Turbines (PATs) in micro hydro-energy resources to replace the conventional turbines as Pelton, Francis and Propeller have been used in countries as USA, Germany and France. In the mean time, in Brazil this practice and the utilization of induction generators working with PATs is still in the scope of the laboratory experiments. This work, based on experimental results carried on in Laboratory of Hydromechanics for Small Hydro Power Plants (Laboratorio Hidromecanico para Pequenas Centrais Hidroeletricas - LHPCH - UNIFEI), (VIANA, 1987), (VIANA e NOGUEIRA, 1990), propose the utilization of asynchronous generator groups operating with PATs. To show the investment cost decrease in micro hydro power plants (MHPs), is showed the Boa Esperanca MPH example, in which is presented a comparison between the synchronous generator group cost working with a Michell-Banki turbine and a asynchronous generator group operating with a PAT. (author)

Multi-fidelity optimization of horizontal axis wind turbines

DEFF Research Database (Denmark)

McWilliam, Michael; Zahle, Frederik; Pavese, Christian

2017-01-01

This paper is concerned with the numerical design optimization of wind turbines. Many examples of wind turbine design optimization in literature rely on simplified analysis in some form. This may lead to sub-optimal design, because the optimizer does not see the full fidelity of the problem....... Finally, AMMF was used in full aero-elastic wind turbine rotor design optimization problem based on the DTU 10 MW reference wind turbine design. Mixed results were achieved for the final study and further work is needed to find the best configuration for AMMF....

Energy balance of hydro-aggregate with Pelton water turbine

International Nuclear Information System (INIS)

Obretenov, V.

2005-01-01

One of the major tasks in the field of hydraulic power engineering refers to machines and equipment modernization in the hydropower plants and pumped storage power plants commissioned more than 20 years ago. The increase of hydraulic units operation efficiency will allow in a number of cases to substantially reduce the specific water consumption and to drive the output of electric energy up. In these cases it is crucial to find out the operational efficiency of individual system elements and to precisely focus the modernization endeavours on such elements where the energy losses go beyond all admissible limits. Besides, the determination of the energy losses in the hydro energy turbo system will allow valid defining of hydraulic units operational scope. This work treats the methods of balance study of a hydraulic unit with Peiton water turbine. The experimental results of the balance study of Belmeken pumped storage power plant hydraulic unit No 5 under turbine operational mode are presented

Design and field operation of 1175 MW steam turbine for Ohi Nuclear Power Station

International Nuclear Information System (INIS)

Hirota, Y.; Nakagami, Y.; Fujii, H.; Shibanai, H.

1980-01-01

Two 1,175 MW steam turbine and generator units have been successfully in commercial operation since March 1979 and December 1979 respectively at Ohi Nuclear Power Station of the Kansai Electric Power Company. Those units, the largest in their respective outputs in Japan, have also such remarkable design features as two-stage reheat, nozzle governing turbine, water cooled generator stator and turbine-driven feedwater pumps. This paper covers design features and some topics of various pre-operational tests of the above-mentioned units. (author)

Pump characteristics and applications

CERN Document Server

Volk, Michael

2013-01-01

Providing a wealth of information on pumps and pump systems, Pump Characteristics and Applications, Third Edition details how pump equipment is selected, sized, operated, maintained, and repaired. The book identifies the key components of pumps and pump accessories, introduces the basics of pump and system hydraulics as well as more advanced hydraulic topics, and details various pump types, as well as special materials on seals, motors, variable frequency drives, and other pump-related subjects. It uses example problems throughout the text, reinforcing the practical application of the formulae

Reliable, Lightweight Transmissions For Off-Shore, Utility Scale Wind Turbines

Energy Technology Data Exchange (ETDEWEB)

Jean-Claude Ossyra

2012-10-25

The objective of this project was to reduce the technical risk for a hydrostatic transmission based drivetrain for high-power utility-size wind turbines. A theoretical study has been performed to validate the reduction of cost of energy (CoE) for the wind turbine, identify risk mitigation strategies for the drive system and critical components, namely the pump, shaft connection and hydrostatic transmission (HST) controls and address additional benefits such as reduced deployment costs, improved torque density and improved mean time between repairs (MTBR).

Study of brushless fuel pump (improvement of pump and motor parts). 2nd Report. Blushless dendo fuel pump no kento. 2

Energy Technology Data Exchange (ETDEWEB)

Mine, K; Takada, S; Tatematsu, M; Takeuchi, H [Aisan Industry Co. Ltd., Aichi (Japan)

1992-10-01

A methanol use electrically driven fuel pump was developed as reported in the present report. Mixed fuel of gasoline with alcohol can be handled by a brushless fuel pump which was proposed and improved as reported. The flow rate performance was heightened to 25g/sec by heightening in output power of motor, while the high temperature performance was 17% heightened against the conventional ratio of lowering in flow rate by heightening in vapor jet capacity. Against the corrosiveness of methanol, an in-tank type was applied to the pump, and all its electrically conductive and other mechanical parts were made to be both anti-corrosive and anti-abrasive. It is structurally of a two-stage series turbine type of non-volume form. A sensor method was applied to the motor by confining the miniaturized control circuit of brushless motor in the motor so that the transistor is controlled against the heightening in temperature. The motor is a three-phase half-wave driving motor. Also developed was a fuel supply system which is useful for the mixed fuel covering a range of 100% methanol through 100% gasoline. The present pump is dimensionally interchangeable with the conventional gasoline use one. Its operational life is more than 10000 hours. 3 refs., 17 figs., 1 tab.

Recent technology for nuclear steam turbine-generator units

International Nuclear Information System (INIS)

Moriya, Shin-ichi; Kuwashima, Hidesumi; Ueno, Takeshi; Ooi, Masao

1988-01-01

As the next nuclear power plants subsequent to the present 1,100 MWe plants, the technical development of ABWRs was completed, and the plan for constructing the actual plants is advanced. As for the steam turbine and generator facilities of 1,350 MWe output applied to these plants, the TC6F-52 type steam turbines using 52 in long blades, moisture separation heaters, butterfly type intermediate valves, feed heater drain pumping-up system and other new technologies for increasing the capacity and improving the thermal efficiency were adopted. In this paper, the outline of the main technologies of those and the state of examination when those are applied to the actual plants are described. As to the technical fields of the steam turbine system for ABWRs, the improvement of the total technologies of the plants was promoted, aiming at the good economical efficiency, reliability and thermal efficiency of the whole facilities, not only the main turbines. The basic specification of the steam turbine facilities for 50 Hz ABWR plants and the main new technologies applied to the turbines are shown. The development of 52 in long last stage blades, the development of the analysis program for the coupled vibration of the large rotor system, the development of moisture separation heaters, the turbine control system, condensate and feed water system, and the generators are described. (Kako, I.)

Energy Saving in Water Distribution Network through Pump as Turbine Generators: Economic and Environmental Analysis

Directory of Open Access Journals (Sweden)

Mauro De Marchis

2016-10-01

Full Text Available Complex systems of water distribution networks (WDS are used to supply water to users. WDSs are systems where a lot of distributed energy is available. Historically, this energy is artificially dissipated by pressure reduction valves (PRVs, thanks to which water utilities manage the pressure level in selected nodes of the network. The present study explores the use of economic hydraulic machines, pumps as turbines (PATs to produce energy in a small network located in a town close to Palermo (Italy. The main idea is to avoid dissipation in favor of renewable energy production. The proposed study is applied to a WDN typical of the Mediterranean countries, where the users, to collect water during the period of water scarcity conditions, install private tanks. The presence of private tanks deeply modifies the network from its designed condition. In the proposed analysis, the economic benefit of PATs application in water distribution networks has been investigated, accounting for the presence of users’ private tanks. The analysis, carried out by mean of a mathematical model able to dynamically simulate the water distribution network with PATs, shows the advantage of their installation in terms of renewable energy recovery, even though the energy production of PATs is strictly conditioned by their installation position.

Wind turbines - generating noise or electricity?

International Nuclear Information System (INIS)

Russell, Eric

1999-01-01

Wind turbine technology has made great strides in the past few years. Annual energy output is up by two orders of magnitude and nacelle weight and noise has been halved. Computational fluid dynamics has paid a part in advancing knowledge of air flow and turbulence around wind generators. Current research is focused on how to increase turbine size and improve efficiency. A problem is that while larger wind turbines will produce cheaper electricity, the noise problem will mean that the number of acceptable sites will decrease. The biggest wind generators will need about 800 m clearance from the nearest house. (UK)

Saturated steam turbines for power reactors of WWER-type

International Nuclear Information System (INIS)

Czwiertnia, K.

1978-01-01

The publication deals with design problems of large turbines for saturated steam and with problem of output limitations of single shaft normal speed units. The possibility of unification of conventional and nuclear turbines, which creates the economic basis for production of both types of turbines by one manufacturer based on standarized elements and assemblies is underlined. As separate problems the distribution of nuclear district heating power systems are considered. The choice of heat diagram for district heating saturated steam turbines, the advantages of different diagrams and evaluaton for further development are presented. On this basis a program of unified turbines both condensing and district heating type suitable for Soviet reactors of WWER-440 and WWER-1000 type for planned development of nuclear power in Poland is proposed. (author)

Thermodynamic assessment of a wind turbine based combined cycle

International Nuclear Information System (INIS)

Rabbani, M.; Dincer, I.; Naterer, G.F.

2012-01-01

Combined cycles use the exhaust gases released from a Gas Turbine (GT). Approximately 30–40% of the turbine shaft work is typically used to drive the Compressor. The present study analyzes a system that couples a Wind Turbine (WT) with a combined cycle. It demonstrates how a WT can be used to supply power to the Compressor in the GT cycle and pump fluid through a reheat Rankine cycle, in order to increase the overall power output. Three different configurations are discussed, namely high penetration, low penetration and wind power addition. In the case of a low electricity demand and high penetration configuration, extra wind power is used to compress air which can then be used in the low penetration configuration. During a high load demand, all the wind power is used to drive the pump and compressor and if required additional compressed air is supplied by a storage unit. The analysis shows that increasing the combustion temperature reduces the critical velocity and mass flow rate. Increases in wind speed reduce both energy and exergy efficiency of the overall system. -- Highlights: ► This study analyzes a system that couples a wind turbine with a combined power generation cycle. ► Surplus wind power is used to compress air, which is then stored and used at a later time. ► Increasing the pressure ratio will reduce the work ratio between the Rankine and Brayton cycles. ► A higher combustion temperature will increase the net work output, as well as the system energy and exergy efficiencies.

Dynamic Performance of the Standalone Wind Power Driven Heat Pump

OpenAIRE

H. Li; P.E. Campana; S. Berretta; Y. Tan; J. Yan

2016-01-01

Reducing energy consumption and increasing use of renewable energyin the building sector arecrucial to the mitigation of climate change. Wind power driven heat pumps have been considered as a sustainable measure to supply heat for detached houses, especially those that even don’t have access to the grid. This work is to investigate the dynamic performance of a heat pump system directly driven by a wind turbine. The heat demand of a detached single family house was simulated in details. Accord...

Short term hydroelectric power system scheduling with wind turbine generators using the multi-pass iteration particle swarm optimization approach

International Nuclear Information System (INIS)

Lee, T.-Y.

2008-01-01

This paper uses multi-pass iteration particle swarm optimization (MIPSO) to solve short term hydroelectric generation scheduling of a power system with wind turbine generators. MIPSO is a new algorithm for solving nonlinear optimal scheduling problems. A new index called iteration best (IB) is incorporated into particle swarm optimization (PSO) to improve solution quality. The concept of multi-pass dynamic programming is applied to modify PSO further and improve computation efficiency. The feasible operational regions of the hydro units and pumped storage plants over the whole scheduling time range must be determined before applying MIPSO to the problem. Wind turbine power generation then shaves the power system load curves. Next, MIPSO calculates hydroelectric generation scheduling. It begins with a coarse time stage and searching space and refines the time interval between two time stages and the search spacing pass by pass (iteration). With the cooperation of agents called particles, the near optimal solution of the scheduling problem can be effectively reached. The effects of wind speed uncertainty were also considered in this paper. The feasibility of the new algorithm is demonstrated by a numerical example, and MIPSO solution quality and computation efficiency are compared to those of other algorithms

Dynamic modeling of fluid power transmissions for wind turbines

NARCIS (Netherlands)

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

2011-01-01

Fluid power transmission for wind turbines is quietly gaining more ground/interest. The principle of the various concepts presented so far is to convert aerodynamic torque of the rotor blades into a pressurized fluid flow by means of a positive displacement pump. At the other end of the fluid power

Study on the replacement of last moving blade at lower pressure turbine

International Nuclear Information System (INIS)

Koo, Jae Raeyang; Lee, Woo Kwang; Koo, Woo Sik; Kim, Yeon Hwan

2003-01-01

Vibration of turbine is concerned with array of last moving blade at lower pressure turbine. When last moving blade at lower pressure turbine was replaced, we must consider mass unbalance problems of blades. If mass unbalance happened at rotor, it is impossible to operate turbine. In this paper, we have how to minimize the mass unbalance problems of last moving blade at lower pressure turbine

General characteristics and technical subjects on helium closed cycle gas turbine

International Nuclear Information System (INIS)

Shimomura, Hiroaki

1996-06-01

Making the subjects clarified on nuclear-heated gas turbine that will apply the inherent features of HTGR, the present paper discusses the difference of the helium closed cycle gas turbine, which is a candidate of nuclear gas turbine, with the open cycle gas turbine and indicates inherent problems of closed cycle gas turbine, its effects onto thermal efficiency and turbine output and difficulties due to the pressure ratio and specific speed from use of helium. The paper also discusses effects of the external pressure losses onto the efficiencies of compressor and turbine that are major components of the gas turbine. According to the discussions above, the paper concludes indicating the key idea on heat exchangers for the closed cycle gas turbine and design basis to solve the problems and finally offers new gas turbine conception using nitrogen or air that is changeable into open cycle gas turbine. (author)

From the water wheel to turbines and hydroelectricity. Technological evolution and revolutions

Science.gov (United States)

Viollet, Pierre-Louis

2017-08-01

Since its appearance in the first century BC, the water wheel has developed with increasing pre-industrial activities, and has been at the origin of the industrial revolution for metallurgy, textile mills, and paper mills. Since the nineteenth century, the water wheel has become highly efficient. The reaction turbine appeared by 1825, and continued to undergo technological development. The impulsion turbine appeared for high chutes, by 1880. Other turbines for low-head chutes were further designed. Turbine development was associated, after 1890, with the use of hydropower to generate electricity, both for industrial activities, and for the benefits of cities. A model ;one city + one plant; was followed in the twentieth century by more complex and efficient schemes when electrical interconnection developed, together with pumped plants for energy storage.

Renewable Energy for Water Pumping Applications In Rural Villages; Period of Performance: April 1, 2001--September 1, 2001

Energy Technology Data Exchange (ETDEWEB)

Argaw, N.; Foster, R.; Ellis, A.

2003-07-01

This report introduces conventional and renewable energy sources for water pumping applications in rural villages by reviewing the technologies and illustrating typical applications. As energy sources for water pumping, the report discusses diesel/gasoline/kerosene engines, grid power supplies, traditional windmills, electrical wind turbines, and PV.

Transient behaviour of main coolant pump in nuclear power plants

International Nuclear Information System (INIS)

Delja, A.

1986-01-01

A basic concept of PWR reactor coolant pump thermo-hydraulic modelling in transient and accident operational condition is presented. The reactor coolant pump is a component of the nuclear steam supply system which forces the coolant through the reactor and steam generator, maintaining design heat transfer condition. The pump operating conditions have strong influence on the flow and thermal behaviour of NSSS, both in the stationary and nonstationary conditions. A mathematical model of the reactor coolant pump is formed by using dimensionless homologous relations in the four-quadrant regimes: normal pump, turbine, dissipation and reversed flow. Since in some operational regimes flow of mixture, liquid and steam may occur, the model has additional correction members for two-phase homologous relations. Modular concept has been used in developing computer program. The verification is performed on the simulation loss of offsite power transient and obtained results are presented. (author)

Pumping machinery theory and practice

CERN Document Server

Badr, Hassan M

2014-01-01

Pumping Machinery Theory and Practice comprehensively covers the theoretical foundation and applications of pumping machinery. Key features: Covers characteristics of centrifugal pumps, axial flow pumps and displacement pumpsConsiders pumping machinery performance and operational-type problemsCovers advanced topics in pumping machinery including multiphase flow principles, and two and three-phase flow pumping systemsCovers different methods of flow rate control and relevance to machine efficiency and energy consumptionCovers different methods of flow rate control and relevance to machine effi

Robust Model Predictive Control of a Wind Turbine

DEFF Research Database (Denmark)

Mirzaei, Mahmood; Poulsen, Niels Kjølstad; Niemann, Hans Henrik

2012-01-01

In this work the problem of robust model predictive control (robust MPC) of a wind turbine in the full load region is considered. A minimax robust MPC approach is used to tackle the problem. Nonlinear dynamics of the wind turbine are derived by combining blade element momentum (BEM) theory...... of the uncertain system is employed and a norm-bounded uncertainty model is used to formulate a minimax model predictive control. The resulting optimization problem is simplified by semidefinite relaxation and the controller obtained is applied on a full complexity, high fidelity wind turbine model. Finally...... and first principle modeling of the turbine flexible structure. Thereafter the nonlinear model is linearized using Taylor series expansion around system operating points. Operating points are determined by effective wind speed and an extended Kalman filter (EKF) is employed to estimate this. In addition...

Problems of bentonite rebonding of synthetic system sands in turbine mixers

Directory of Open Access Journals (Sweden)

A. Fedoryszyn

2008-12-01

Full Text Available Turbine (rotor mixers are widely used in foundries for bentonite rebonding of synthetic system sands. They form basic equipment in modern sand processing plants. Their major advantage is the short time of the rebond mixing cycle.Until now, no complete theoretical description of the process of mixing in turbine mixers has been offered. Neither does it seem reasonable to try to adapt the theoretical backgrounds of the mixing process carried out in mixers of other types, for example, rooler mixers [1], to the description of operation of the turbine mixers. Truly one can risk the statement that the individual fundamental operations of mixing in rooler mixers, like kneading, grinding, mixing and thinning, are also performed in turbine mixers. Yet, even if so, in turbine mixers these processes are proceeding at a rate and intensity different than in the roller mixers. The fact should also be recalled that the theoretical backgrounds usually relate to the preparation of sand mixtures from new components, and this considerably restricts the field of application of these descriptions when referred to rebond mixing of the system sand. The fundamentals of the process of the synthetic sand rebonding with bentonite require determination and description of operations, like disaggregation, even distribution of binder and water within the entire volume of the rebonded sand batch, sand grains coating, binder activation and aeration.This study presents the scope of research on the sand rebonding process carried out in turbine mixers. The aim has been to determine the range and specific values of the designing and operating parameters to get optimum properties of the rebonded sand as well as energy input in the process.

Transients in low pressure pumping circuits: a language oriented for the problem

International Nuclear Information System (INIS)

De Bernardinis, B.; Siccardi, F.

1977-01-01

Following a previous work (Vallombrosa 1974) a specialized language was developed for transients in low pressure pumping circuits, when the liquid column separation phenomenon may happen or is to be avoided. The first generation of the programming code is given. Numerical schemes go beyond the usual characteristic integration techniques now available and make it possible to atrack the solution of problems in which on the one hand, the differential equations are nonlinear on account of the variations of the celerity with pressure, and on the other, the pressure of a dispersed gaseous phase in the liquid influences the energetic dissipation mechanisms. The oriented language allows the simulation of the main constituents of the circuits, pumping stations, reservoirs, air tanks, piezometric wells, condensers, variable resistances, conduit junctions, both during normal functioning and in cavitation conditions. Special control instructions on the programming code allow such a simulation language to be easily employed even by people not specifically competent in computer progr

Wind tunnel experiments to prove a hydraulic passive rotor speed control concept for variable speed wind turbines (poster)

NARCIS (Netherlands)

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

2012-01-01

As alternative to geared and direct drive solutions, fluid power drive trains are being developed by several institutions around the world. The common configuration is where the wind turbine rotor is coupled to a hydraulic pump. The pump is connected through a high pressure line to a hydraulic motor

Development and Implementation of Mechanistic Terry Turbine Models in RELAP-7 to Simulate RCIC Normal Operation Conditions

Energy Technology Data Exchange (ETDEWEB)

Zhao, Haihua [Idaho National Lab. (INL), Idaho Falls, ID (United States); Zou, Ling [Idaho National Lab. (INL), Idaho Falls, ID (United States); Zhang, Hongbin [Idaho National Lab. (INL), Idaho Falls, ID (United States); O' Brien, James Edward [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2016-09-01

As part of the efforts to understand the unexpected “self-regulating” mode of the RCIC (Reactor Core Isolation Cooling) systems in Fukushima accidents and extend BWR RCIC and PWR AFW (Auxiliary Feed Water) operational range and flexibility, mechanistic models for the Terry turbine, based on Sandia’s original work [1], have been developed and implemented in the RELAP-7 code to simulate the RCIC system. In 2016, our effort has been focused on normal working conditions of the RCIC system. More complex off-design conditions will be pursued in later years when more data are available. In the Sandia model, the turbine stator inlet velocity is provided according to a reduced-order model which was obtained from a large number of CFD (computational fluid dynamics) simulations. In this work, we propose an alternative method, using an under-expanded jet model to obtain the velocity and thermodynamic conditions for the turbine stator inlet. The models include both an adiabatic expansion process inside the nozzle and a free expansion process outside of the nozzle to ambient pressure. The combined models are able to predict the steam mass flow rate and supersonic velocity to the Terry turbine bucket entrance, which are the necessary input information for the Terry turbine rotor model. The analytical models for the nozzle were validated with experimental data and benchmarked with CFD simulations. The analytical models generally agree well with the experimental data and CFD simulations. The analytical models are suitable for implementation into a reactor system analysis code or severe accident code as part of mechanistic and dynamical models to understand the RCIC behaviors. The newly developed nozzle models and modified turbine rotor model according to the Sandia’s original work have been implemented into RELAP-7, along with the original Sandia Terry turbine model. A new pump model has also been developed and implemented to couple with the Terry turbine model. An input

Noise from wind turbines

Energy Technology Data Exchange (ETDEWEB)

Fegeant, Olivier [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Building Sciences

2002-02-01

A rapid growth of installed wind power capacity is expected in the next few years. However, the siting of wind turbines on a large scale raises concerns about their environmental impact, notably with respect to noise. To this end, variable speed wind turbines offer a promising solution for applications in densely populated areas like the European countries, as this design would enable an efficient utilisation of the masking effect due to ambient noise. In rural and recreational areas where wind turbines are sited, the ambient noise originates from the action of wind on the vegetation and about the listener's ear (pseudo-noise). It shows a wind speed dependence similar to that of the noise from a variable speed wind turbine and can therefore mask the latter for a wide range of conditions. However, a problem inherent to the design of these machines is their proclivity to pure tone generation, because of the enhanced difficulty of avoiding structural resonances in the mechanical parts. Pure tones are deemed highly annoying and are severely regulated by most noise policies. In relation to this problem, the vibration transmission of structure-borne sound to the tower of the turbine is investigated, in particular when the tower is stiffened at its upper end. Furthermore, since noise annoyance due to wind turbine is mostly a masking issue, the wind-related sources of ambient noise are studied and their masking potentials assessed. With this aim, prediction models for wind-induced vegetation noise and pseudo-noise have been developed. Finally, closely related to the effect of masking, is the difficulty, regularly encountered by local authorities and wind farm developers, to measure noise immission from wind turbines. A new measurement technique has thus been developed in the course of this work. Through improving the signal-to-noise ratio between wind turbine noise and ambient noise, the new technique yields more accurate measurement results.

Test specification for decant pump and winch assembly. Revision 2

International Nuclear Information System (INIS)

Staehr, T.W.

1995-01-01

This specification provides the requirements for testing of the vertical turbine decant pump including the floating suction with load sensing winch control, instrumentation and the associated PLC/PC control system. All assembly necessary for testing including piping, temporary wiring, etc., shall be performed by the Seller. All referenced figures are at the back of this document. The testing consists of performance testing, winch testing and calibration, instrumentation verification testing and run-in testing of the pump. Testing shall be done in the presence and under the direction of the Buyer in accordance with this procedure

Specific features of steam turbine design at LMZ

International Nuclear Information System (INIS)

Pichugin, I.I.; Tsvetkov, A.M.; Simkin, M.S.

1993-01-01

General structural layouts of the condensation steam turbines produced by the Leningrad metalworks (LM) are considered. Currently LM produced 50 types and modifications of steam turbines with the capacity from 30 up to 1200 MW. Problems of turbine efficiency and ways of the flow section improvement are discussed

TNX/HLW Long Shaft Pumps 1995-2000

International Nuclear Information System (INIS)

VanPelt, B.

2002-01-01

Problems with long shaft pumps are becoming clearer due to increased use, better instrumentation, more analysis, and increased testing activity. The problems are with reliability and not with hydraulic performance. The root cause of reliability problems is usually excessive vibration caused by design. The outlook for satisfactory pumps is improved as understanding of problems increases. Promising developments are emerging such as the tilt pad bearing. Alternative configurations, such as gas filled columns and submerged motor pumps, will require development. Continued development, in general, should be expected due to changing technology and industry changes. This report describes thirteen distinct pump programs starting with leakage of original mixer pumps in the 1980s and ending with the testing of tilt pad bearings now in progress. Eight of the programs occurred from 1996 to 2000. All involve long shaft pumps; all involve testing at TNX; and all involve a problem of some kind. The co mmon technical issue among the activities is vibration and shaft (or rotor) instability due to journal bearings. In every case, excessive shaft vibration is a reasonable and probable explanation for some or all of the problems

Deflector plants turbine aeration

International Nuclear Information System (INIS)

Miller, D.E.; Sheppard, A.R.; Widener, D.W.

1991-01-01

Water quality requirements have become a focal point in recent re-licensing of hydroelectric projects. The Federal Energy Regulatory Commission has significantly increased the relevance of license conditions to insure that turbine discharges meet state or other specific criteria for dissolved oxygen (D.O.). Due to naturally occurring depletion of D.O. at increased depths in large reservoirs, water withdrawn from this strata may result in unacceptably low levels of D.O. Different researchers have evaluated various methods of improving D.O. content in hydro turbine discharges, including; diffusers, weirs, oxygen injection, and variations of turbine venting. The authors describe an approach called deflector plate turbine aeration. This computer based, engineered approach allows systems to be evaluated, designed, and installed with predictable performance and costs. Many experts in this field now agree that, to the extent practical, turbine venting offers the most dependable, maintenance free, and cost effective solution to the low D.O. problem. The approach presented in this paper has resulted in proven results

Vapor pumps and gas-driven machines

International Nuclear Information System (INIS)

Guillet, R.

1991-01-01

The vapor pump, patented in 1979 by Gaz de France, is an additional mass and heat exchanger which uses the combustion air of fuel-burning machines as an additional cold source. This cold source is preheated and, above all, humidified before reaching the burner, by means of the residual sensible and latent heat in the combustion products of the fuel-burning process. This final exchanger thus makes it possible, in many cases, to recover all the gross calorific value of natural gas, even when the combustion products leave the process at a wet temperature greater than 60 0 C, the maximum dew point of the products of normal combustion. Another significant advantage of the vapor pump being worth highlighting is the selective recycling of water vapor by the vapor pump which reduces the adiabatic combustion temperature and the oxygen concentration in the combustion air, two factors which lead to considerable reductions in nitrogen oxides formation, hence limiting atmospheric pollution. Alongside a wide range of configurations which make advantageous use of the vapor pump in association with gas-driven machines and processes, including gas turbines, a number of boiler plant installations are also presented [fr

The new 6 MW gas turbine for the power generation; Die neue 6 MW Gasturbine fuer die Stromerzeugung

Energy Technology Data Exchange (ETDEWEB)

Blaswich, Michael; Theis, Sascha [MAN Diesel and Turbo SE, Oberhausen (Germany)

2012-07-01

MAN Diesel and Turbo SE (Oberhausen, Federal Republic of Germany) had developed a new gas turbine in the 6 MW class. This device is the founding stone for a family of gas turbines which at first cover the power range from 6 to 8 MW for the propulsion of pumps, compressors and electric devices. The two-shaft industrial gas turbine consists of a gas generator with an axial compressor with eleven levels, six external single combustion chambers, one two-step high-pressure turbine and a two-step power turbine. Beside the two-shaft industrial gas turbine, there exists a single-shaft industrial gas turbine for the power generation. The single-shaft industrial gas turbine consists of three turbine stages, a gas turbine compressor and combustion chamber being identical in construction to the two-shaft industrial gas turbine. The gas turbine package contains the gas turbine module as well as a filter module. The gas turbine was successfully tested. Further tests and the commissioning of the first customer's plant are planned for this year.

Laser Velocimeter Measurements in the Pump of an Automotive Torque Converter Part II – Effect of Pump Speed and Oil Viscosity

Directory of Open Access Journals (Sweden)

Ronald D. Flack

2000-01-01

Full Text Available The velocity field inside a torque converter pump was studied for two separate effects: variable pump rotational speed and variable oil viscosity. Three-dimensional velocity measurements were taken using a laser velocimeter for both the pump mid- and exit planes. The effect ofvariable pump rotational speed was studied by running the pump at two different speeds and holding speed ratio (pump rotational speed]turbine rotational speed constant. Similarly, the effect of viscosity on the pump flow field was studied by varying the temperature and]or using two different viscosity oils as the working fluid in the pump. Threedimensional velocity vector plots, through-flow contour plots, and secondary flow profiles were obtained for both pump planes and all test conditions. Results showed that torque converter mass flows increased approximately linearly with increasing pump rotational speed (and fixed speed ratio but that the flow was not directly proportional to pump rotational speed. However, mass flows were seen to decrease as the oil viscosity was decreased with a resulting increased Reynolds number; for these conditions the high velocity regions were seen to decrease in size and low velocity regions were seen to increase in size. In the pump mid-plane strong counter-clockwise secondary flows and in the exit plane strong clockwise secondary flows were observed. The vorticities and slip factors were calculated from the experimental results and are presented. The torque core-to-shell and blade-to-blade torque distributions were calculated for both planes. Finally, the flow fields were seen to demonstrate similitude when Reynolds numbers were matched.

Promising Direction of Perfection of the Utilization Combine Cycle Gas Turbine Units

Directory of Open Access Journals (Sweden)

Gabdullina Albina I.

2017-01-01

Full Text Available Issues of improving the efficiency of combined cycle gas turbines (CCGT recovery type have been presented. Efficiency gas turbine plant reaches values of 45 % due to rise in temperature to a gas turbine to 1700 °C. Modern technologies for improving the cooling gas turbine components and reducing the excess air ratio leads to a further increase of the efficiency by 1-2 %. Based on research conducted at the Tomsk Polytechnic University, it shows that the CCGT efficiency can be increased by 2-3 % in the winter time due to the use of organic Rankine cycle, low-boiling substances, and air-cooled condensers (ACC. It is necessary to apply the waste heat recovery with condensation of water vapor from the flue gas, it will enhance the efficiency of the CCGT by 2-3 % to increase the efficiency of the heat recovery steam boiler (HRSB to 10-12 %. Replacing electric pumps gas turbine engine (GTE helps to reduce electricity consumption for auxiliary needs CCGT by 0.5-1.5 %. At the same time the heat of flue gas turbine engine may be useful used in HRSB, thus will increase the capacity and efficiency of the steam turbine.

Turbine disintegration debris

International Nuclear Information System (INIS)

Holecek, M.; Martinec, P.; Malotin, V.; Peleska, P.; Voldrich, J.

1997-01-01

The determination, evaluation and analysis of possible unacceptable consequences of the disintegration turbine (turbo-set) missiles is a part of the wide conceived project put by the company Nuclear Power Plant Mochovce (NPPM), the Slovak Republic. The aim of the project is to take measures reducing the probability of striking a target of safety importance in NPPM by a turbine (turbo-set) missile below the prescribed limit of 10 -6 per turbine year. Following the IAEA Safety Guides, all potential events leading to the generation of a missile are to be analysed. It is necessary to evaluate the probability of unacceptable consequences of such missiles and analyse each event whose probability is not acceptable low. This complex problem thus carries especially: complex analysis of fragment generation; evaluation of the probability of unacceptable events; location of strike zones of possible turbine missiles; assessment the possibility of the turbo-set casing penetration; and projection of additional design requirements if necessary

Bimetallic Blisks with Shrouded Turbine Blades for Gas Turbine Engines

Directory of Open Access Journals (Sweden)

L. A. Magerramova

2015-01-01

Full Text Available The paper discusses prospects of using blisks with shrouded blades. Increasing an engine life and efficiency as well as mass reduction can also be achieved by increasing blade numbers and decreasing disk diameter. But design engineers are faced with the problem of blade placement because of the disk size and root dimensions.The problem of increasing life and cyclic durability, vibration strength, and lightweight design of the turbine gas turbine wheels, can be solved by an elimination of blade - disk locks.The technology of manufacturing one-piece blisks by connecting the blades with the disc part using hot isostatic pressing was developed. This technology allows us to use blades with shrouds. It is necessary to increase efficiency and to improve high cycle fatigue performance of rotor blades.One of the pressing problems is to ensure the necessary position of shrouds in relation to each other in the manufacturing process as well as in the service. Numerical studies of the influence of the shroud mounting position on blade strength during operation allowed us to develop a methodology of choosing a shroud mounting position.Based on the two turbine wheels (LPT and HPT calculations advantages of blisk design with respect to the lock-based design were shown. Application of bimetallic blisks with shrouded blades resulted in a lifespan increase and weight reduction.In addition, other advantages of blisk design are as follows: possible reduction in the number of parts, elimination of leaks and fretting that take place in the blade - disk locks, exception of expensive broaching operations and disk alloy saving. The shortcoming is elimination of damping in root connection. In addition, there are no widely used repair methods.Despite these disadvantages the usage of bimetallic turbine blisks with shrouded blades is very promising.

Two stage turbine for rockets

Science.gov (United States)

Veres, Joseph P.

1993-01-01

The aerodynamic design and rig test evaluation of a small counter-rotating turbine system is described. The advanced turbine airfoils were designed and tested by Pratt & Whitney. The technology represented by this turbine is being developed for a turbopump to be used in an advanced upper stage rocket engine. The advanced engine will use a hydrogen expander cycle and achieve high performance through efficient combustion of hydrogen/oxygen propellants, high combustion pressure, and high area ratio exhaust nozzle expansion. Engine performance goals require that the turbopump drive turbines achieve high efficiency at low gas flow rates. The low mass flow rates and high operating pressures result in very small airfoil heights and diameters. The high efficiency and small size requirements present a challenging turbine design problem. The shrouded axial turbine blades are 50 percent reaction with a maximum thickness to chord ratio near 1. At 6 deg from the tangential direction, the nozzle and blade exit flow angles are well below the traditional design minimum limits. The blade turning angle of 160 deg also exceeds the maximum limits used in traditional turbine designs.

Report on an investigation into heat pumps in China in fiscal 1995; 1995 nendo Chugoku ni okeru heat pump system ni kansuru chosa hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-03-01

The paper surveyed the present status, the status of spread, and the technical development of the technology of heat pumps for residential and industrial uses in China. Main examples of installation of heat pumps are cited below: steam drive absorption type refrigerators in Beijing; sea water heat source turbo heat pumps in Qingdao; hot water drive absorption type refrigerators in Beijing; oil-fueled absorption type water cooling and heating appliances in Beijing; ice latent heat storage airconditioning systems using electrically-driven screw chiller in Beijing; temperature rising systems using electrically-driven heat pump of the solar energy utilization warm water swimming pool in Guangdong Province; cooling water supply using waste heat utilization absorption type refrigerator of the alcohol plant in Shandong Province; timber drying systems using electrically-driven heat pump, and marine product cultivation systems in Quangdong Province; distillation systems using steam turbine heat pump in Jiangxi Province. The demand for heat pumps is expected to be 20 million units under the 9th 5-year plan, and the development of equipment is thought to go toward promotion of energy conservation, low noise, multi-type or multi-functional air conditioning equipment, and computer use. 137 figs., 40 tabs.

Assessment of guide vane self-excitation stability at small openings in pump flow

International Nuclear Information System (INIS)

Nennemann, B; Sallaberger, M; Henggeler, U; Gentner, C; Parkinson, E

2012-01-01

A parameter study of self-excited pump turbine guide vane instability at small openings using a combined CFD-1DOF approach shows that clear tendencies are difficult to obtain. Two types of boundary conditions can be used in the simulations: prescribed mass flow and prescribed pressure. Simulations with both show results that - for one specific operating condition - are consistent with a self-excited guide vane incident at a prototype pump turbine. However, over a larger range of reduced velocities, the tendencies obtained with the two boundary condition types are not always consistent. Pressure boundary conditions may be the more realistic option. Results then show that with increasing reduced velocity, guide vanes will eventually reach static instability or divergence. This may not be problematic. In contrast, passing through a zone of dynamic instability during operation should and can be avoided.

Through-flow analysis of steam turbines operating under partial admission

International Nuclear Information System (INIS)

Delabriere, H.; Werthe, J.M.

1993-05-01

In order to produce electric energy with improved efficiency, Electricite de France has to check the performances of equipment proposed by manufacturers. In the specific field of steam turbines, one of the main tools of analysis is the quasi 3D through flow computer code CAPTUR, which enables the calculation of all the aerothermodynamic parameters in a steam turbine. The last development that has been performed on CAPTUR is the extension to a calculation of a flow within a turbine operating under partial admission. For such turbines, it is now possible to calculate an internal flow field, and determine the efficiency, in a much more accurate way than with previous methods, which consist in an arbitrary efficiency correction on an averaged 1D flow calculation. From the aerodynamic point of view, partial admission involves specific losses in the first stage, then expansion and turbulent mixing just downstream of the first stage. Losses in the first stage are of very different types: windage, pumping and expansion at the ends of an admission sector. Their values have been estimated, with help of experimental results, and then expressed as a slow down coefficient applied to the relative velocity at the blade outlet. As for the flow downstream the first stage, a computational analysis has been made with specific 2D and 3D codes. It has led to define the numerical treatment established in the CAPTUR code. Some problems had to be solved to make compatible a quasi 3D formulation, making an average in the azimutal direction and using a streamline curvature method, with an absolute 3D phenomenon. Certain limitations of the working conditions were first adopted, but a generalization is on hand. The calculation of a nuclear HP steam turbine operating under partial admission has been performed. Calculation results are in good accordance with tests results, especially as regards the expansion line along the stages. The code CAPTUR will be particularly useful for the calculation

Structural Reliability Aspects in Design of Wind Turbines

DEFF Research Database (Denmark)

Sørensen, John Dalsgaard

2007-01-01

Reliability assessment, optimal design and optimal operation and maintenance of wind turbines are an area of significant interest for the fast growing wind turbine industry for sustainable production of energy. Offshore wind turbines in wind farms give special problems due to wake effects inside...... the farm. Reliability analysis and optimization of wind turbines require that the special conditions for wind turbine operation are taken into account. Control of the blades implies load reductions for large wind speeds and parking for high wind speeds. In this paper basic structural failure modes for wind...... turbines are described. Further, aspects are presented related to reliability-based optimization of wind turbines, assessment of optimal reliability level and operation and maintenance....

Analysis of Turbine Load Rejection for APR1400 using SPACE

Energy Technology Data Exchange (ETDEWEB)

Kim, Sang Jin; Park, Chan Eok; Choi, Jong Ho; Lee, Gyu Cheon [KEPCO Engineering and Construction Co. Ltd., Deajeon (Korea, Republic of)

2016-10-15

Turbine Load Rejection event is one of the Performance Related Design Basis Event (PRDBE) that can be stabilized using plant control systems without any safety system actuation. The initiation of the event is turbine load rejection from 100% to 5% in 0.019 seconds. The NSSS control systems of APR1400 is composed of the Power Control System (PCS) and the Process-Component Control System (P-CCS). The PCS includes Reactor Regulating System (RRS), Reactor Power Cutback System (RPCS) and Digital Rod Control System (DRCS). The P-CCS includes the Pressurizer Pressure Control System (PPCS), the Pressurizer Level Control System (PLCS), the Feedwater Control System (FWCS) and the Steam Bypass Control System (SBCS). Turbine load rejection results in the increase of secondary pressure due to sudden blocking of steam flow to turbine. Then the Reactor Coolant System (RCS) cooling through steam generators is decreased rapidly and the RCS temperature will be increased. Turbine load rejection is a typical event to test NSSS control systems since it requires the automatic response of all major NSSS control systems. It is shown that the NSSS control systems of APR1400 have the capability to stabilize the plant without any safety system actuation for turbine load rejection event. This analysis results show that SPACE code has the capability to analyze the turbine load rejection event. However, further validation is necessary for other PRDBEs such as Two Main Feedwater Pumps Trip, Turbine Load Step Change and Turbine Load Ramp Down (5%/min) to verify the capability of SPACE for the full range of performance analyses.

Analysis of Turbine Load Rejection for APR1400 using SPACE

International Nuclear Information System (INIS)

Kim, Sang Jin; Park, Chan Eok; Choi, Jong Ho; Lee, Gyu Cheon

2016-01-01

Turbine Load Rejection event is one of the Performance Related Design Basis Event (PRDBE) that can be stabilized using plant control systems without any safety system actuation. The initiation of the event is turbine load rejection from 100% to 5% in 0.019 seconds. The NSSS control systems of APR1400 is composed of the Power Control System (PCS) and the Process-Component Control System (P-CCS). The PCS includes Reactor Regulating System (RRS), Reactor Power Cutback System (RPCS) and Digital Rod Control System (DRCS). The P-CCS includes the Pressurizer Pressure Control System (PPCS), the Pressurizer Level Control System (PLCS), the Feedwater Control System (FWCS) and the Steam Bypass Control System (SBCS). Turbine load rejection results in the increase of secondary pressure due to sudden blocking of steam flow to turbine. Then the Reactor Coolant System (RCS) cooling through steam generators is decreased rapidly and the RCS temperature will be increased. Turbine load rejection is a typical event to test NSSS control systems since it requires the automatic response of all major NSSS control systems. It is shown that the NSSS control systems of APR1400 have the capability to stabilize the plant without any safety system actuation for turbine load rejection event. This analysis results show that SPACE code has the capability to analyze the turbine load rejection event. However, further validation is necessary for other PRDBEs such as Two Main Feedwater Pumps Trip, Turbine Load Step Change and Turbine Load Ramp Down (5%/min) to verify the capability of SPACE for the full range of performance analyses

Optimization and Reliability Problems in Structural Design of Wind Turbines

DEFF Research Database (Denmark)

Sørensen, John Dalsgaard

2007-01-01

are discussed. Limit state equations are presented for fatigue limit states and for ultimate limit states with extreme wind load, and illustrated by bending failure. Illustrative examples are presented, and as a part of the results optimal reliability levels are obtained which corresponds to an annual...... reliability index equal to 3. An example with fatigue failure indicates that the reliability level is almost the same for single wind turbines and for wind turbines in wind farms if the wake effects are modeled equivalently in the design equation and the limit state equation....

Component design considerations for gas turbine HTGR waste-heat power plant

International Nuclear Information System (INIS)

McDonald, C.F.; Vrable, D.L.

1976-01-01

Component design considerations are described for the ammonia waste-heat power conversion system of a large helium gas-turbine nuclear power plant under development by General Atomic Company. Initial component design work was done for a reference plant with a 3000-MW(t) High-Temperature Gas-Cooled Reactor (HTGR), and this is discussed. Advanced designs now being evaluated include higher core outlet temperature, higher peak system pressures, improved loop configurations, and twin 4000-MW(t) reactor units. Presented are the design considerations of the major components (turbine, condenser, heat input exchanger, and pump) for a supercritical ammonia Rankine waste heat power plant. The combined cycle (nuclear gas turbine and waste-heated plant) has a projected net plant efficiency of over 50 percent. While specifically directed towards a nuclear closed-cycle helium gas-turbine power plant (GT-HTGR), it is postulated that the bottoming waste-heat cycle component design considerations presented could apply to other low-grade-temperature power conversion systems such as geothermal plants

LQR Feedback Control Development for Wind Turbines Featuring a Digital Fluid Power Transmission System

DEFF Research Database (Denmark)

Pedersen, Niels Henrik; Johansen, Per; Andersen, Torben O.

2016-01-01

with a DFP motor, which has been combined with the NREL 5-MW reference wind turbine model. A classical variable speed control strategy for wind speeds below rated is proposed for the turbine, where the pump displacement is fixed and the digital motor displacement is varied for pressure control. The digital...... for such digital systems are complicated by its non-smooth behavior. In this paper a control design approach for a digital displacement machine® is proposed and a performance analysis of a wind turbine using a DFP transmission is presented. The performance evaluation is based on a dynamic model of the transmission...... invariant model. Using full-field flow wind profiles as input, the design approach and control performance is verified by simulation in the dynamic model of the wind turbine featuring the DFP transmission. Additionally, the performance is compared to that of the conventional NREL reference turbine...

Market experiences with small wind turbines

International Nuclear Information System (INIS)

Van Deijl, T.J.

1990-01-01

An overview is given of the marketing experiences of Lagerwey Windturbines with the exploitation of small wind turbines. Attention is paid to the market mechanisms which effect the sale and implementation of small wind turbines: payback of surplus power, provincial and regional subsidies, grid connection costs, energy prices, and flexible solutions for grid connections. Also problems with municipalities with regard to regulations or construction licenses are discussed. Some recommendations are given to stimulate the market for small wind turbines. 1 fig., 1 ref

Some problems in exploitation of deep-pumping wells in Tatarian oil fields

Energy Technology Data Exchange (ETDEWEB)

Ishemguzhin, S B

1970-01-01

Difficulty has been experienced in pumping paraffinic oil with rod pumps. The rods have scrapers to remove paraffin from tubing walls, however this method does not work well. In an effort to improve pumping efficiency, gas anchors of various types were tried. Best results were obtained when the pumps, equipped with gas anchors, were placed about 300 m under the dynamic liquid level, and separated gas was steadily removed through the annulus. With this arrangement, more complete filling of the pump was achieved. Experience has shown that with separate production of gas from wells, the useful stroke of the pump plunger is increased as well as productivity of deep-pumping equipment.

Investigation of the Flow in Pelton Turbines and the Influence of the Casing

OpenAIRE

Heinz-Bernd Matthias; Josef Prost; Christian Rossegger

1997-01-01

At the institute for waterpower and pumps at the University of Technology Vienna we do a lot of research work observing the flow in the casing and the buckets of Pelton turbines. One interest of our research is to find criteria to estimate the influence of the splash water distribution in the casing on the turbine efficiency. Knowing the splash water distribution it is further possible to develop methods to provide visual documentation of the flow in and around the buckets from the beginning ...

The effect of pump cavitation on the design of the primary pumps for C.F.R

International Nuclear Information System (INIS)

Worster, R.C.

1976-01-01

In the design appraisal of the sodium pumps for the primary circuit of the proposed 1300 MW(e) CFR it has been recognised that cavitation, its effects and its control, is the outstanding hydraulic design problem. Careful consideration of this problem and of the possible effects of pump cavitation on the performance of other reactor systems has led to the conclusion that it is more prudent at present to specify pumps with zero cavitation at normal full speed operating conditions. Under abnormal operation it may be necessary to reduce the pumps' speed to prevent cavitation in the pumps or associated equipment. The principal reasons for this decision were uncertainties concerning the possibility of erosion due to limited cavitation in sodium and the possibility of pump cavitation noise interfering with acoustic detection of malfunctioning of reactor components or of boiling in the reactor core

Canned motor pumps at Heavy Water Project, Baroda

International Nuclear Information System (INIS)

Batra, R.K.; Waishampayan, S.C.

1981-01-01

Pumps to be used in heavy water plants must be reliable and should require negligible maintenance, because most of them are totally unapproachable under normal circumstances. Canned motor pumps fulfil these requirements. Their design features are described briefly. The details of: (1) the pumps in the isotopic exchange tower and (2) pumps for liquid ammonia and catalyst are given. Problems faced during commissioning of such pumps in Baroda Heavy Water Project were bulging of rotors of tower pumps, bulging of stators, jamming and failure of bearings. Solution of these problems is described. (M.G.B.)

Tests of cooling water pumps at Dukovany nuclear power plant

International Nuclear Information System (INIS)

Travnicek, J.

1986-01-01

Tests were performed to examine the operating conditions of the 1600 BQDV cooling pumps of the main coolant circuit of unit 1 of the Dukovany nuclear power plant. For the pumps, the performance was tested in the permissible operating range, points were measured below this range and the guaranteed operating point was verified. Pump efficiency was calculated from the measured values. The discussion of the measurement of parameters has not yet been finished because the obtained values of the amount delivered and thus of the pump efficiency were not up to expectation in all detail. It was also found that for obtaining the guaranteed flow the pump impeller had to be opened to 5deg -5.5deg instead of the declared 3deg. Also tested were pump transients, including the start of the pump, its stop, the operation and failure of one of the two pumps. In these tests, pressures were also measured at the inlet and the outlet of the inner part of the TG 11 turbine condenser. It was shown that the time course and the pressure course of the processes were acceptable. In addition to these tests, pressure losses in the condenser and the cooling water flow through the feed pump electromotor cooler wre tested for the case of a failure of one of the two pumps. (E.S.)

Pumped storage - necessary and sensible

International Nuclear Information System (INIS)

Kiener, E.

2006-01-01

This comprehensive article takes a look at the long-established technique of using pumped storage schemes to temporarily store electricity. Here, excess power is used to pump water back into high-level reservoirs during low-load periods so that it can be used to generate electricity during peak periods. Ecological and energy-loss aspects are discussed as are the objections raised by environmental agencies. An overview of the present situation and the operation of such installations in Switzerland is provided. Future developments in this area and the role played in the European power system are discussed. Comparisons are made between hydro-electric peak power production and that using gas turbines and other systems. In particular, the efficiencies and the carbon dioxide loading involved are looked at. Also, the situation with power generation using new renewables is examined and the economic prerequisites for the operation of such schemes are looked at

Voltage Quality of Grid Connected Wind Turbines

DEFF Research Database (Denmark)

Chen, Zhe; Blaabjerg, Frede; Sun, Tao

2004-01-01

Grid connected wind turbines may cause quality problems, such as voltage variation and flicker. This paper discusses the voltage variation and flicker emission of grid connected wind turbines with doubly-fed induction generators. A method to compensate flicker by using a voltage source converter...

MAINTAINANCE OF KAPLAN TURBINE TO ENHANCE THE EFFICIENCY

OpenAIRE

Mr. Shakti Prasanna Khadanga*; Nitish Kumar; Milind Kumar Singh; L. Raj Kumar

2016-01-01

Hydro power plant is the source of renewable energy which leads to reduction in burning of fossil fuels. So the environment is no longer polluted. This project depicts how sediment erosion occurs in Kaplan turbine and the various components of Kaplan turbine where actually erosion takes place. It reduces efficiency [7] and life of hydro power turbine but also causes problems in operations and maintenance. We conducted some necessary test on Kaplan turbine in fluid power laboratory. We are d...

Health Effects Related to Wind Turbine Noise Exposure

DEFF Research Database (Denmark)

Schmidt, Jesper Hvass; Klokker, Mads

2014-01-01

BACKGROUND: Wind turbine noise exposure and suspected health-related effects thereof have attracted substantial attention. Various symptoms such as sleep-related problems, headache, tinnitus and vertigo have been described by subjects suspected of having been exposed to wind turbine noise...... existing statistically-significant evidence indicating any association between wind turbine noise exposure and tinnitus, hearing loss, vertigo or headache. LIMITATIONS: Selection bias and information bias of differing magnitudes were found to be present in all current studies investigating wind turbine...

Effect of pump limiter throat on pumping efficiency

International Nuclear Information System (INIS)

Ghendrih, P.; Grosman, A.; Samain, A.; Capes, H.; Morera, J.P.

1988-01-01

The necessary control of plasma edge density has led to the development of pump limiters to achieve this task. On Tore Supra, where a large part of the program is devoted to plasma edge studies, two types of such density control apparatus have been implemented, a set of pump limiters and the pumps associated to the ergodic divertor (magnetically assisted pump limiters). Generally two different kinds of pump limiters can be used, those with a throat which drives the plasma from the open edge plasma (SOL) to the neutralizer plate, and those without or with a very short throat. We are interested here in this aspect of the pump limiter concept, i.e. on the throat effect on neutral density build-up in the vicinity of the pumping plates (and hence on pumping efficieny). The underlying idea of this throat effect can be readily understood; indeed while the neutral capture in pump limiters without throats is only a ballistic effect, on expects the plasma to improve the efficiency of pump-limiters via plasma-neutral-sidewall interactions in the throat. This problem has been studied both numerically and analytically. The paper is divided as follows. In section 2, we describe the basic features of pump-limiters which are modelized by the numerical code Cezanne. Section 3 is devoted to the throat length effect considering in particular the neutral density profile in the throat and the neutral density buil-up as a function of the throat lenght. In section 4, we show that the plugging effect occurs for reasonnable values of throat lengths. An analytical value of the plugging length is discussed and compared to the values obtained numerically

Lubricants : the lifeblood of wind turbines

Energy Technology Data Exchange (ETDEWEB)

Tremblay, Y. [Petro-Canada, Calgary, AB (Canada)

2009-07-01

With the significant investments in wind turbine equipment, companies need to exercise due diligence when it comes to the types of lubricants and fluids used. Mechanical and equipment issues can often be eliminated with improved maintenance practices and the appropriate selection of lubricants. This presentation discussed lubricants as being the lifeblood of wind turbines. The presentation first provided an overview and discussed wind turbine trends and application trends. The technical aspects of fluid formation were presented. Lubrication maintenance practices and oil monitoring were discussed. Last, key industry tests, and OEM specifications for bearings, gearboxes, and wind turbines were identified. It was concluded that improved maintenance practices in combination with the correct lubricant selection can address several operating problems. figs.

The Petit Canal Sea water pumped storage plant in Guadeloupe island: a tool to allow the intermittent renewable energy development

International Nuclear Information System (INIS)

Brun, Pierre; Mahiou, Bernard; Ayoub, Michel

2015-01-01

In the frame of the 2011 call for proposal 'Energy storage' launched by the ADEME (French Environment and Energy Management Agency, EDF aims to propose a 50 MW seawater pumped storage project for the island of Guadeloupe. The project, named SEPMERI (in French Stockage d'Energie par Pompage en Mer permettant le developpement des Energies Renouvelables Intermittentes), or SPSIRE (in English Seawater Pumped Storage allowing the development of Intermittent Renewable Energy). This project needs to build an upper reservoir with a capacity of 4.7 Mm 3 storing 0.6 GWh (12 hour time duration service at full load) with embankments and an overall watertightness. The average water-head is 67 m. This innovating scheme, equipped with pumps as turbines hosted in an iron pre-cast powerhouse at the foot of the cliff will be able to store energy and to smooth the intermittent renewable energy generation. Such project will improve the hosting capacity for the intermittent generation upper the legal limit of 30% applied to preserve the safety of power systems in French insular systems. In 2050, the need of storage with seawater pumped power plants could reach some thousand of MW in France and in boundary European countries and ten times more in the rest of the world. The number of sites which could be developed for seawater pumped storage power plants is very important (about several thousand), even taking into account all the constraints. The technological option using an iron pre-cast powerhouse can be deployed in the majority of market cases (low and medium water-head) with equipment either pump as turbines, either reversible turbines/pumps. It has been shown that the learning curve could lead to construction costs lower than 1500 Euros/kW (excluding grid connection) competitive with those of on shore pumped storage projects based on upgrading existing hydro power plants. (authors)

Research of performance prediction to energy on hydraulic turbine

International Nuclear Information System (INIS)

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

2012-01-01

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.

Gas turbine electric generator

International Nuclear Information System (INIS)

Nemoto, Masaaki; Yuhara, Tetsuo.

1993-01-01

When troubles are caused to a boundary of a gas turbine electric generator, there is a danger that water as an operation medium for secondary circuits leaks to primary circuits, to stop a plant and the plant itself can not resume. Then in the present invention, helium gases are used as the operation medium not only for the primary circuits but also for the secondary circuits, to provide so-called a direct cycle gas turbine system. Further, the operation media of the primary and secondary circuits are recycled by a compressor driven by a primary circuit gas turbine, and the turbine/compressor is supported by helium gas bearings. Then, problems of leakage of oil and water from the bearings or the secondary circuits can be solved, further, the cooling device in the secondary circuit is constituted as a triple-walled tube structure by way of helium gas, to prevent direct leakage of coolants into the reactor core even if cracks are formed to pipes. (N.H.)

Advanced load alleviation for wind turbines using adaptive trailing edge flaps: Sensoring and control

Energy Technology Data Exchange (ETDEWEB)

Andersen, Peter Bjoern

2010-02-15

The purpose of wind turbines and their predecessors the windmill, is to convert the energy in the wind to usable energy forms. Whereas windmills of the past focused on the conversion of wind power to torque for grinding, pumping and winching, modern wind turbines convert the wind energy into electric power. They do so through incorporation of generators, which convert mechanical torque into electricity. Wind turbines are designed to keep the overall cost per produced Kilo Watt hour as low as possible. One way of improving the performance and lifetime of the wind turbine is through active flow control. Active control is often considered costly but if the lifespan of the components can be increased it could be justifiable. This thesis covers various aspects of 'smart control' such as control theory, sensoring, optimization, experiments and numerical modeling. (author)

Portable photovoltaic irrigation pumps

Energy Technology Data Exchange (ETDEWEB)

Furber, J. D.

1980-07-01

Experiences in developing a solar-powered irrigation pump to meet the needs of poor farmers in developing nations are summarized. The design which evolved is small and portable, employing a high-efficiency electric pump, powered by photovoltaic panels. Particular emphasis is placed on how the system works, and on early field problems experienced with the first prototypes. The resolution of these problems and the performance of actual systems in various countries is presented and user responses are noted.

Cavitation performance improvement of high specific speed mixed-flow pump

International Nuclear Information System (INIS)

Chen, T; Sun, Y B; Wu, D Z; Wang, L Q

2012-01-01

Cavitation performance improvement of large hydraulic machinery such as pump and turbine has been a hot topic for decades. During the design process of the pumps, in order to minimize size, weight and cost centrifugal and mixed-flow pump impellers are required to operate at the highest possible rotational speed. The rotational speed is limited by the phenomenon of cavitation. The hydraulic model of high-speed mixed-flow pump with large flow rate and high pumping head, which was designed based on the traditional method, always involves poor cavitation performance. In this paper, on the basis of the same hydraulic design parameters, two hydraulic models of high-speed mixed-flow pump were designed by using different methods, in order to investigate the cavitation and hydraulic performance of the two models, the method of computational fluid dynamics (CFD) was adopted for internal flow simulation of the high specific speed mixed-flow pump. Based on the results of numerical simulation, the influences of impeller parameters and three-dimensional configuration on pressure distribution of the blades' suction surfaces were analyzed. The numerical simulation results shows a better pressure distribution and lower pressure drop around the leading edge of the improved model. The research results could provide references to the design and optimization of the anti-cavitation blade.

Pumped storage power plants in Denmark. Pumpekraftvaerker i Danmark

Energy Technology Data Exchange (ETDEWEB)

1988-12-15

In 1988 there are about 250 pumped storage power plants throughout the world, yet it is difficult to obtain data about them. They are usually situated in mountainous areas so that great differences in height can be obtained between the upper and lower water storage facilities. These plants consist of the power system (turbines, pumps, generators, motors, etc.) natural or artificial water storage facilities, and water routes, (in and outgoing constructions, pressure pipes, etc.). In Denmark, reversible pumping turbines are preferred, and here specific Danish products are examined (62.5MW and a 125 MW). Possible designs for water storage basins are analyzed in detail, also with regard to their comparative economic advantages. It has been considered reasonable to site this kind of power plant in Danish coastal regions, this would be the first case where the sea has been used for the lower water storage basin. Possible sites in Jutland and on the island of Als have been investigated. In a basin for a 250 MW pumped storage power plant with optimal production throughout 8 hours, a siting 60 m above sea level could cover power production for an area of about 100 hectars. Material for a dam surrounding the lower water storage system could be produced when digging out the basin. The dam should be about 20m higher than the surrounding terrain and the volume would be about 3,2 mio. m/sup 3/. The filled basin would contain 14.0 mio. m/sup 3/ water. The velocity and volume of outgoing water masses would be very considerable and would exact safety precautions to protect ships and bathers. A tentative cost benefit analysis is presented which indicates that the possible establishment of this type of power plant in Denmark could be of considerable interest. (AB). 15 refs.

Prospects for the domestic production of large-sized cast blades and vanes for industrial gas turbines

Science.gov (United States)

Kazanskiy, D. A.; Grin, E. A.; Klimov, A. N.; Berestevich, A. I.

2017-10-01

Russian experience in the production of large-sized cast blades and vanes for industrial gas turbines is analyzed for the past decades. It is noted that the production of small- and medium-sized blades and vanes made of Russian alloys using technologies for aviation, marine, and gas-pumping turbines cannot be scaled for industrial gas turbines. It is shown that, in order to provide manufacturability under large-scale casting from domestic nickel alloys, it is necessary to solve complex problems in changing their chemical composition, to develop new casting technologies and to optimize the heat treatment modes. An experience of PAO NPO Saturn in manufacturing the blades and vanes made of ChS88U-VI and IN738-LC foundry nickel alloys for the turbines of the GTE-110 gas turbine unit is considered in detail. Potentialities for achieving adopted target parameters for the mechanical properties of working blades cast from ChS88UM-VI modified alloy are established. For the blades made of IN738-LC alloy manufactured using the existing foundry technology, a complete compliance with the requirements of normative and technical documentation has been established. Currently, in Russia, the basis of the fleet of gas turbine plants is composed by foreign turbines, and, for the implementation of the import substitution program, one can use the positive experience of PAO NPO Saturn in casting blades from IN738-LC alloy based on a reverse engineering technique. A preliminary complex of studies of the original manufacturer's blades should be carried out, involving, first of all, the determination of geometric size using modern measurement methods as well as the studies on the chemical compositions of the used materials (base metal and protective coatings). Further, verifying the constructed calculation models based on the obtained data, one could choose available domestic materials that would meet the operating conditions of the blades according to their heat resistance and corrosion

Inservice testing of vertical pumps

International Nuclear Information System (INIS)

Cornman, R.E. Jr.; Schumann, K.E.

1994-01-01

This paper focuses on the problems that may occur with vertical pumps while inservice tests are conducted in accordance with existing American Society of Mechanical Engineers Code, Section XI, standards. The vertical pump types discussed include single stage, multistage, free surface, and canned mixed flow pumps. Primary emphasis is placed on the hydraulic performance of the pump and the internal and external factors to the pump that impact hydraulic performance. In addition, the paper considers the mechanical design features that can affect the mechanical performance of vertical pumps. The conclusion shows how two recommended changes in the Code standards may increase the quality of the pump's operational readiness assessment during its service life

Controlled Velocity Testing of an 8-kW Wind Turbine

Energy Technology Data Exchange (ETDEWEB)

Larwood, S.; Sencenbaugh, J.; Acker, B.

2001-07-31

This paper describes a case study of the controlled-velocity test of an 8-kW wind turbine. The turbine was developed in response to the U.S. Department of Energy's small wind turbine program. As background, the prototype development is discussed. The turbine mechanical and electrical components are described. The turbine was tested on a flatbed truck and driven down an airfield runway at constant relative wind speed. Horizontal furling was used to control over-speed. Various parameters were changed to determine their effects on furling. The testing showed that the machine had insufficient rotor offset for adequate furling. Also, a rotor resonance problem was discovered and remedied. Problems associated with taking the measurements made it difficult to determine if the truck test was a suitable method for code validation. However, qualitative observations gleaned from the testing justified the effort.

Aeroelastic stability analysis of a Darrieus wind turbine

Science.gov (United States)

Popelka, D.

1982-02-01

An aeroelastic stability analysis was developed for predicting flutter instabilities on vertical axis wind turbines. The analytical model and mathematical formulation of the problem are described as well as the physical mechanism that creates flutter in Darrieus turbines. Theoretical results are compared with measured experimental data from flutter tests of the Sandia 2 Meter turbine. Based on this comparison, the analysis appears to be an adequate design evaluation tool.

Aeroelastic stability analysis of a Darrieus wind turbine

Energy Technology Data Exchange (ETDEWEB)

Popelka, D.

1982-02-01

An aeroelastic stability analysis has been developed for predicting flutter instabilities on vertical axis wind turbines. The analytical model and mathematical formulation of the problem are described as well as the physical mechanism that creates flutter in Darrieus turbines. Theoretical results are compared with measured experimental data from flutter tests of the Sandia 2 Meter turbine. Based on this comparison, the analysis appears to be an adequate design evaluation tool.

Evaluation of wind turbine gearboxes; Evaluering af vindmoellegear

Energy Technology Data Exchange (ETDEWEB)

NONE

2003-08-15

A wind turbine's gearbox is the single component in which failures with risk of breakdown occur. The problems typically occur in the form of pitting damages in cogwheels and breakdown in bearings. The number of gearbox problems are increasing especially in 600 and 750 kW wind turbines. This project comprises a failure detection and analysis system, a gearbox calculation program, load monitoring, and finally dynamics of the mechanical transmission system. (BA)

Model Predictive Control for Load Frequency Control with Wind Turbines

Directory of Open Access Journals (Sweden)

Yi Zhang

2015-01-01

Full Text Available Reliable load frequency (LFC control is crucial to the operation and design of modern electric power systems. Considering the LFC problem of a four-area interconnected power system with wind turbines, this paper presents a distributed model predictive control (DMPC based on coordination scheme. The proposed algorithm solves a series of local optimization problems to minimize a performance objective for each control area. The scheme incorporates the two critical nonlinear constraints, for example, the generation rate constraint (GRC and the valve limit, into convex optimization problems. Furthermore, the algorithm reduces the impact on the randomness and intermittence of wind turbine effectively. A performance comparison between the proposed controller with and that without the participation of the wind turbines is carried out. Good performance is obtained in the presence of power system nonlinearities due to the governors and turbines constraints and load change disturbances.

Unsteady Flow in a Supersonic Turbine with Variable Specific Heats

Science.gov (United States)

Dorney, Daniel J.; Griffin, Lisa W.; Huber, Frank; Sondak, Douglas L.; Turner, James (Technical Monitor)

2001-01-01

Modern high-work turbines can be compact, transonic, supersonic, counter-rotating, or use a dense drive gas. The vast majority of modern rocket turbine designs fall into these Categories. These turbines usually have large temperature variations across a given stage, and are characterized by large amounts of flow unsteadiness. The flow unsteadiness can have a major impact on the turbine performance and durability. For example, the Space Transportation Main Engine (STME) fuel turbine, a high work, transonic design, was found to have an unsteady inter-row shock which reduced efficiency by 2 points and increased dynamic loading by 24 percent. The Revolutionary Reusable Technology Turbopump (RRTT), which uses full flow oxygen for its drive gas, was found to shed vortices with such energy as to raise serious blade durability concerns. In both cases, the sources of the problems were uncovered (before turbopump testing) with the application of validated, unsteady computational fluid dynamics (CFD) to the designs. In the case of the RRTT and the Alternate Turbopump Development (ATD) turbines, the unsteady CFD codes have been used not just to identify problems, but to guide designs which mitigate problems due to unsteadiness. Using unsteady flow analyses as a part of the design process has led to turbine designs with higher performance (which affects temperature and mass flow rate) and fewer dynamics problems. One of the many assumptions made during the design and analysis of supersonic turbine stages is that the values of the specific heats are constant. In some analyses the value is based on an average of the expected upstream and downstream temperatures. In stages where the temperature can vary by 300 to 500 K, however, the assumption of constant fluid properties may lead to erroneous performance and durability predictions. In this study the suitability of assuming constant specific heats has been investigated by performing three-dimensional unsteady Navier

Radar-cross-section reduction of wind turbines. part 1.

Energy Technology Data Exchange (ETDEWEB)

Brock, Billy C.; Loui, Hung; McDonald, Jacob J.; Paquette, Joshua A.; Calkins, David A.; Miller, William K.; Allen, Steven E.; Clem, Paul Gilbert; Patitz, Ward E.

2012-03-05

In recent years, increasing deployment of large wind-turbine farms has become an issue of growing concern for the radar community. The large radar cross section (RCS) presented by wind turbines interferes with radar operation, and the Doppler shift caused by blade rotation causes problems identifying and tracking moving targets. Each new wind-turbine farm installation must be carefully evaluated for potential disruption of radar operation for air defense, air traffic control, weather sensing, and other applications. Several approaches currently exist to minimize conflict between wind-turbine farms and radar installations, including procedural adjustments, radar upgrades, and proper choice of low-impact wind-farm sites, but each has problems with limited effectiveness or prohibitive cost. An alternative approach, heretofore not technically feasible, is to reduce the RCS of wind turbines to the extent that they can be installed near existing radar installations. This report summarizes efforts to reduce wind-turbine RCS, with a particular emphasis on the blades. The report begins with a survey of the wind-turbine RCS-reduction literature to establish a baseline for comparison. The following topics are then addressed: electromagnetic model development and validation, novel material development, integration into wind-turbine fabrication processes, integrated-absorber design, and wind-turbine RCS modeling. Related topics of interest, including alternative mitigation techniques (procedural, at-the-radar, etc.), an introduction to RCS and electromagnetic scattering, and RCS-reduction modeling techniques, can be found in a previous report.

Parametric Analysis of a Two-Shaft Aeroderivate Gas Turbine of 11.86 MW

Directory of Open Access Journals (Sweden)

R. Lugo-Leyte

2015-08-01

Full Text Available The aeroderivate gas turbines are widely used for power generation in the oil and gas industry. In offshore marine platforms, the aeroderivative gas turbines provide the energy required to drive mechanically compressors, pumps and electric generators. Therefore, the study of the performance of aeroderivate gas turbines based on a parametric analysis is relevant to carry out a diagnostic of the engine, which can lead to operational as well as predictive and/or corrective maintenance actions. This work presents a methodology based on the exergetic analysis to estimate the irrevesibilities and exergetic efficiencies of the main components of a two-shaft aeroderivate gas turbine. The studied engine is the Solar Turbine Mars 100, which is rated to provide 11.86 MW. In this engine, the air is compressed in an axial compressor achieving a pressure ratio of 17.7 relative to ambient conditions and a high pressure turbine inlet temperature of 1220 °C. Even if the thermal efficiency associated to the pressure ratio of 17.7 is 1% lower than the maximum thermal efficiency, the irreversibilities related to this pressure ratio decrease approximately 1 GW with respect to irreversibilities of the optimal pressure ratio for the thermal efficiency. In addition, this paper contributes to develop a mathematical model to estimate the high turbine inlet temperature as well as the pressure ratio of the low and high pressure turbines.

Unsteady boundary layer development on a wind turbine blade: an experimental study of a surrogate problem

Science.gov (United States)

Cadel, Daniel R.; Zhang, Di; Lowe, K. Todd; Paterson, Eric G.

2018-04-01

Wind turbines with thick blade profiles experience turbulent, periodic approach flow, leading to unsteady blade loading and large torque fluctuations on the turbine drive shaft. Presented here is an experimental study of a surrogate problem representing some key aspects of the wind turbine unsteady fluid mechanics. This experiment has been designed through joint consideration by experiment and computation, with the ultimate goal of numerical model development for aerodynamics in unsteady and turbulent flows. A cylinder at diameter Reynolds number of 65,000 and Strouhal number of 0.184 is placed 10.67 diameters upstream of a NACA 63215b airfoil with chord Reynolds number of 170,000 and chord-reduced frequency of k=2π fc/2/V=1.5. Extensive flow field measurements using particle image velocimetry provide a number of insights about this flow, as well as data for model validation and development. Velocity contours on the airfoil suction side in the presence of the upstream cylinder indicate a redistribution of turbulent normal stresses from transverse to streamwise, consistent with rapid distortion theory predictions. A study of the boundary layer over the suction side of the airfoil reveals very low Reynolds number turbulent mean streamwise velocity profiles. The dominance of the high amplitude large eddy passages results in a phase lag in streamwise velocity as a function of distance from the wall. The results and accompanying description provide a new test case incorporating moderate-reduced frequency inflow for computational model validation and development.

Analysis of the possibility to cover energy demand from renewable sources on the motive power of the heat pump in low-energy building

Directory of Open Access Journals (Sweden)

Knapik Maciej

2017-01-01

Full Text Available The article presents the problem of the demand for electricity for the heat pump and an analysis of the coverage of this demand by renewable energy sources such as wind turbines and photovoltaic cells, which generate electricity in low energy buildings. Low-energy and passive constructions are a result of introduction of new ideas in building design process. Their main objective is to achieve a significant reduction in demand for renewable primary energy, necessary to cover the needs of these buildings, mostly related to their heating, ventilation and domestic hot water This article presents the results of numerical analysis and calculations performed in MATLAB software, based on typical meteorological years. The results showed that renewable energy sources, can allow to cover a significant demand for electricity, that is required to power the heat pump it is economically justified.

Concept of turbines for ultrasupercritical, supercritical, and subcritical steam conditions

Science.gov (United States)

Mikhailov, V. E.; Khomenok, L. A.; Pichugin, I. I.; Kovalev, I. A.; Bozhko, V. V.; Vladimirskii, O. A.; Zaitsev, I. V.; Kachuriner, Yu. Ya.; Nosovitskii, I. A.; Orlik, V. G.

2017-11-01

The article describes the design features of condensing turbines for ultrasupercritical initial steam conditions (USSC) and large-capacity cogeneration turbines for super- and subcritical steam conditions having increased steam extractions for district heating purposes. For improving the efficiency and reliability indicators of USSC turbines, it is proposed to use forced cooling of the head high-temperature thermally stressed parts of the high- and intermediate-pressure rotors, reaction-type blades of the high-pressure cylinder (HPC) and at least the first stages of the intermediate-pressure cylinder (IPC), the double-wall HPC casing with narrow flanges of its horizontal joints, a rigid HPC rotor, an extended system of regenerative steam extractions without using extractions from the HPC flow path, and the low-pressure cylinder's inner casing moving in accordance with the IPC thermal expansions. For cogeneration turbines, it is proposed to shift the upper district heating extraction (or its significant part) to the feedwater pump turbine, which will make it possible to improve the turbine plant efficiency and arrange both district heating extractions in the IPC. In addition, in the case of using a disengaging coupling or precision conical bolts in the coupling, this solution will make it possible to disconnect the LPC in shifting the turbine to operate in the cogeneration mode. The article points out the need to intensify turbine development efforts with the use of modern methods for improving their efficiency and reliability involving, in particular, the use of relatively short 3D blades, last stages fitted with longer rotor blades, evaporation techniques for removing moisture in the last-stage diaphragm, and LPC rotor blades with radial grooves on their leading edges.

Experiences and results from Elkraft 1 MW wind turbine

Energy Technology Data Exchange (ETDEWEB)

Raben, N; Jensen, F V [SEAS Distribution A.m.b.A., Wind Power Dept., Haslev (Denmark); Oeye, S [DTU, Inst. for Energiteknik, Lyngby (Denmark); Markkilde Petersen, S; Antoniou, I [Risoe National Lab., Wind Energy and Atmospheric Physics Dept., Roskilde (Denmark)

1999-03-01

The Elkraft 1 MW Demonstration wind turbine was at the time of installation in 1993 the largest stall controlled wind turbine in the world. It was constructed to allow accurate comparison of two different forms of operation: pitch control and stall control. A comprehensive programme for the investigation of the two operation modes was established. This paper presents the main experiences from five years of operation and measurements. For a three-year period the wind turbine was in operation in stall controlled mode. During this period the turbine faced problems of various significance. Especially lightning strikes and unusually poor wind conditions caused delays of the project. In early 1997, the wind turbine was modified to enable pitch controlled operation. The gearbox ratio was changed in order to allow higher rotor speed, the hydraulic system was altered and new control software was installed. Tests were carried out successfully during the spring of 1997 and the wind turbine has since been operating as a pitch controlled wind turbine. The most significant events and problems are presented and commented in this paper along with results from the measurement programme. The results cover both stall and pitch controlled operation and include power curves, annual energy production, structural loads, fatigue loads etc. (au) 10 refs.

On the inverse problem of blade design for centrifugal pumps and fans

Science.gov (United States)

Kruyt, N. P.; Westra, R. W.

2014-06-01

The inverse problem of blade design for centrifugal pumps and fans has been studied. The solution to this problem provides the geometry of rotor blades that realize specified performance characteristics, together with the corresponding flow field. Here a three-dimensional solution method is described in which the so-called meridional geometry is fixed and the distribution of the azimuthal angle at the three-dimensional blade surface is determined for blades of infinitesimal thickness. The developed formulation is based on potential-flow theory. Besides the blade impermeability condition at the pressure and suction side of the blades, an additional boundary condition at the blade surface is required in order to fix the unknown blade geometry. For this purpose the mean-swirl distribution is employed. The iterative numerical method is based on a three-dimensional finite element method approach in which the flow equations are solved on the domain determined by the latest estimate of the blade geometry, with the mean-swirl distribution boundary condition at the blade surface being enforced. The blade impermeability boundary condition is then used to find an improved estimate of the blade geometry. The robustness of the method is increased by specific techniques, such as spanwise-coupled solution of the discretized impermeability condition and the use of under-relaxation in adjusting the estimates of the blade geometry. Various examples are shown that demonstrate the effectiveness and robustness of the method in finding a solution for the blade geometry of different types of centrifugal pumps and fans. The influence of the employed mean-swirl distribution on the performance characteristics is also investigated.

On the inverse problem of blade design for centrifugal pumps and fans

International Nuclear Information System (INIS)

Kruyt, N P; Westra, R W

2014-01-01

The inverse problem of blade design for centrifugal pumps and fans has been studied. The solution to this problem provides the geometry of rotor blades that realize specified performance characteristics, together with the corresponding flow field. Here a three-dimensional solution method is described in which the so-called meridional geometry is fixed and the distribution of the azimuthal angle at the three-dimensional blade surface is determined for blades of infinitesimal thickness. The developed formulation is based on potential-flow theory. Besides the blade impermeability condition at the pressure and suction side of the blades, an additional boundary condition at the blade surface is required in order to fix the unknown blade geometry. For this purpose the mean-swirl distribution is employed. The iterative numerical method is based on a three-dimensional finite element method approach in which the flow equations are solved on the domain determined by the latest estimate of the blade geometry, with the mean-swirl distribution boundary condition at the blade surface being enforced. The blade impermeability boundary condition is then used to find an improved estimate of the blade geometry. The robustness of the method is increased by specific techniques, such as spanwise-coupled solution of the discretized impermeability condition and the use of under-relaxation in adjusting the estimates of the blade geometry. Various examples are shown that demonstrate the effectiveness and robustness of the method in finding a solution for the blade geometry of different types of centrifugal pumps and fans. The influence of the employed mean-swirl distribution on the performance characteristics is also investigated. (paper)

Achievement report for fiscal 1989. Research and development of ceramic gas turbine (Portable regenerative two-shaft radial turbine for electric power generation); 1989 nendo ceramic gas turbine no kenkyu kaihatsu seika hokokusho. Kahanshiki hatsuden'yo saisei nijikushiki radial turbine

Energy Technology Data Exchange (ETDEWEB)

NONE

1990-05-01

Research and development has been advanced on a ceramic gas turbine with an output of 300-kW class, and having thermal efficiency of 42% or higher. Activities were performed in the following three fields: 1) research of heat resistant ceramic members, 2) research of elementary technologies, and 3) studies on design, prototype fabrication, and operation. In Item 1, forming and sintering were performed on a scroll of large size difficult for forming, an output turbine nozzle, a gas generator turbine nozzle, a shroud and back-shroud for same to extract technological problems. In addition, discussions were given on a method to bond the rotor of the gas generator turbine with the shaft. In Item 2, elementary tests were given on the rotary heat-storage type heat exchanger which has high relative technological difficulty and requires a great amount of time for development, wherein the thermal efficiency was improved by improving the flow velocity distribution. Furthermore, a combustor for the metal gas turbine was developed. Specifications were established for a test device required for hot spin tests of the gas generator turbine and output turbine, and part of the device was fabricated. In Item 3, detailed design was made for the metallic basic-type gas turbine to become the master form of the turbine to be developed. (NEDO)

Potential scour for marine current turbines based on experience of offshore wind turbine

International Nuclear Information System (INIS)

Chen, L; Lam, W H; Shamsuddin, A H

2013-01-01

The oceans have tremendous untapped natural resources. These sources are capable to make significant contribution to our future energy demands. Marine current energy offers sustainable and renewable alternative to conventional sources. Survival problems of Marine Current Turbines (MCTs) need to be addressed due to the harsh marine environment. The analogous researches in wind turbine have been conducted. Some of the results and knowledge are transferable to marine current energy industry. There still exist some gaps in the state of knowledge. Scour around marine structures have been well recognised as an engineering issue as scour is likely to cause structural instability. This paper aims to review different types of foundation of MCTs and potential scour and scour protection around these foundations based on the experience of offshore wind turbine farm.

Viability of using different types of main oil pipelines pump drives

Science.gov (United States)

Zakirzakov, A. G.; Zemenkov, Yu D.; Akulov, K. A.

2018-05-01

The choice of the pumping units' drive of main oil pipelines is of great importance both for design of pipelines and for modernization of existing ones. At the beginning of oil pipeline transport development, due to the limited number and types of energy sources, the choice was not difficult. The combustion energy of the pumped product was often the only available energy resource for its transportation. In this regard, the pipelines that had autonomous energy sources favorably differed from other energy consumers in the sector. With the passage of time, with the development of the country's electricity supply system, the electric drive for power-line equipment of oil pipelines becomes the dominant type of a pumping station drive. Nowadays, the traditional component is an essential factor when choosing some type of the drive. For many years, oil companies have been using electric drives for pumps, while gas transport enterprises prefer self-contained gas turbines.

Techno-Economic Analysis of Gas Turbine Compressor Washing to Combat Fouling

OpenAIRE

Abass, Kabir Oliade

2015-01-01

Among the major deterioration problems a gas turbine encountered while in operation is compressor blade fouling. This is the accumulation and adhesion of dirt and sediment on the compressor blade which contributes between 70 to 85% of gas turbine performance loss. Fouling reduces turbine air mass flow capacity, compressor pressure ratio and overall gas turbine efficiency. In most cases, its effect does not manifest immediately in gas turbine power output and efficiency since they are not meas...

Lightning protection of wind turbines

Energy Technology Data Exchange (ETDEWEB)

Soerensen, T; Brask, M H [DEFU (Denmark); Jensen, F V; Raben, N [SEAS (Denmark); Saxov, J [Nordjyllandsvaerket (Denmark); Nielsen, L [Vestkraft (Denmark); Soerensen, P E [Risoe National Lab. (Denmark)

1999-03-01

Lightning damage to wind turbines is a serious problem for Danish power companies, who have experienced some cases with very costly lightning damage and a large number of cases with minor damage. The most costly cases include one catastrophic damage to an entire wind turbine, and several cases of destruction of blades, main bearings, generators and control systems. Over the years there have been several hundreds of cases with minor damage - typically damage and interruptions of the control and communication systems, or the power systems. The Danish power companies anticipate that the lightning threat will be even bigger for the large off-shore wind turbine installations that are currently being planned in Denmark. Furthermore, it is known from the off-shore wind turbines at Vindeby in Denmark that the costs of inspection and particularly repair work must be expected to be much higher off-shore as compared to wind turbines on land. These considerations was the background for a two year project concerned with investigation of lighting damages and with the formulation of a DEFU Recommendation for lightning protection of wind turbines, which was published in January 1999. The project was funded by the Danish power companies Elsam, Eltra, Elkraft and by DEFU. (au)

Wind turbine blade waste in 2050.

Science.gov (United States)

Liu, Pu; Barlow, Claire Y

2017-04-01

Wind energy has developed rapidly over the last two decades to become one of the most promising and economically viable sources of renewable energy. Although wind energy is claimed to provide clean renewable energy without any emissions during operation, but it is only one side of the coin. The blades, one of the most important components in the wind turbines, made with composite, are currently regarded as unrecyclable. With the first wave of early commercial wind turbine installations now approaching their end of life, the problem of blade disposal is just beginning to emerge as a significant factor for the future. This paper is aimed at discovering the magnitude of the wind turbine blade waste problem, looking not only at disposal but at all stages of a blade's lifecycle. The first stage of the research, the subject of this paper, is to accurately estimate present and future wind turbine blade waste inventory using the most recent and most accurate data available. The result will provide a solid reference point to help the industry and policy makers to understand the size of potential environmental problem and to help to manage it better. This study starts by estimating the annual blade material usage with wind energy installed capacity and average blade weight. The effect of other waste contributing factors in the full lifecycle of wind turbine blades is then included, using industrial data from the manufacturing, testing and in-service stages. The research indicates that there will be 43 million tonnes of blade waste worldwide by 2050 with China possessing 40% of the waste, Europe 25%, the United States 16% and the rest of the world 19%. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

SINGLE PHASE ANALYTICAL MODELS FOR TERRY TURBINE NOZZLE

Energy Technology Data Exchange (ETDEWEB)

Zhao, Haihua; Zhang, Hongbin; Zou, Ling; O' Brien, James

2016-11-01

All BWR RCIC (Reactor Core Isolation Cooling) systems and PWR AFW (Auxiliary Feed Water) systems use Terry turbine, which is composed of the wheel with turbine buckets and several groups of fixed nozzles and reversing chambers inside the turbine casing. The inlet steam is accelerated through the turbine nozzle and impacts on the wheel buckets, generating work to drive the RCIC pump. As part of the efforts to understand the unexpected “self-regulating” mode of the RCIC systems in Fukushima accidents and extend BWR RCIC and PWR AFW operational range and flexibility, mechanistic models for the Terry turbine, based on Sandia National Laboratories’ original work, has been developed and implemented in the RELAP-7 code to simulate the RCIC system. RELAP-7 is a new reactor system code currently under development with the funding support from U.S. Department of Energy. The RELAP-7 code is a fully implicit code and the preconditioned Jacobian-free Newton-Krylov (JFNK) method is used to solve the discretized nonlinear system. This paper presents a set of analytical models for simulating the flow through the Terry turbine nozzles when inlet fluid is pure steam. The implementation of the models into RELAP-7 will be briefly discussed. In the Sandia model, the turbine bucket inlet velocity is provided according to a reduced-order model, which was obtained from a large number of CFD simulations. In this work, we propose an alternative method, using an under-expanded jet model to obtain the velocity and thermodynamic conditions for the turbine bucket inlet. The models include both adiabatic expansion process inside the nozzle and free expansion process out of the nozzle to reach the ambient pressure. The combined models are able to predict the steam mass flow rate and supersonic velocity to the Terry turbine bucket entrance, which are the necessary input conditions for the Terry Turbine rotor model. The nozzle analytical models were validated with experimental data and

Achievement report for fiscal 1992. Research and development of ceramic gas turbine (Portable regenerative double-shaft ceramic gas turbine for portable power generation); 1992 nendo ceramic gas turbine no kenkyu kaihatsu seika hokokusho. Kahanshiki hatsuden'yo saiseishiki ceramic gas turbine

Energy Technology Data Exchange (ETDEWEB)

NONE

1993-05-01

Research and development has been advanced on a ceramic gas turbine (CGT) with an output of 300-kW class and thermal efficiency of 42% or higher. Activities were performed in the following three fields: 1) research of heat resistant ceramic members, 2) research of elementary technologies, and 3) studies on design, prototype fabrication, and operation. In Item 1, research was performed on forming the heat resistant ceramic members, and all-ceramic members constituting the basic type gas turbine were fabricated. Improvements were given on the problems discovered in the heat shock test, and the hot spin test. In Item 2, elementary researches were made on the basic technologies for the ceramic gas turbine, such as on the heat exchanger, combustor, and ceramic turbine, wherein discussions were given on improvement of mechanical strength and performance. In Item 3, design and prototype fabrication were performed on the basic type ceramic gas turbine, based on the results of research operations on the basic type (metallic gas turbine). Adjustment operations were launched on some of the components. (NEDO)

Materials for water pump mechanical seals

International Nuclear Information System (INIS)

Brousse, P.

1992-01-01

In view of the continually increasing power ratings of conventional and nuclear power plants and the related reliability and safety problems, plant builders have had to develop seal systems compatible with current water pump performances. In 1970, EDF/R and DD was already concerned by this problem. It soon became obvious that the nature of the materials used for the friction surfaces was decisive for seal durability. Exceptional loads (transients, high vibration levels, etc...) hasten aging. To begin with, friction surfaces consisted of a hard material (tungsten carbide) mated with a soft material (carbon). Resistance was unpredictable and not compatible with industrial requirements. Tests performed on the EDF/R and DD test benches evidenced the same types of degradation. The mechanical seal manufacturers then began to use ceramic materials (silicon carbide), which raised high expectations. Unfortunately, these were recent materials and their manufacturing process was not thoroughly understood. Hopes were soon dashed in many applications, including that of mechanical seals. Fluctuating results were obtained over the next few years. The raw material suppliers made progress, especially with regard to reducing fragility. On a parallel, the mechanical seal manufacturers initiated comparative tests on the friction resistance of materials. It has also been established that ceramics have to be stringently supervised at all levels: part design, inspection, assembly, use. EDF has much insisted that mechanical seal suppliers guarantee the constant quality of their products. EDF/R and DD has systematically tested new sensitive devices, under normal and exceptional conditions, prior to their installation at the plants. At the present time, the silicon carbides proposed by the mechanical seal suppliers are entirely satisfactory. The carbon mating surface was far less problematic. The required reliability was obtained by replacing resin binder carbons by the more resistant

Pump failure leads to alternative vertical pump condition monitoring technique

International Nuclear Information System (INIS)

DeVilliers, Adriaan; Glandon, Kevin

2011-01-01

Condition monitoring and detecting early signs of potential failure mechanisms present particular problems in vertical pumps. Most often, the majority of the pump assembly is not readily accessible for visual or audible inspection or conventional vibration monitoring techniques using accelerometers and/or proximity sensors. The root cause failure analysis of a 2-stage vertical centrifugal service-water pump at a nuclear power generating facility in the USA is presented, highlighting this long standing challenge in condition monitoring of vertical pumps. This paper will summarize the major findings of the root cause analysis (RCA), highlight the limitations of traditional monitoring techniques, and present an expanded application of motor current monitoring as a means to gain insight into the mechanical performance and condition of a pump. The 'real-world' example of failure, monitoring and correlation of the monitoring technique to a detailed pump disassembly inspection is also presented. This paper will explain some of the reasons behind well known design principles requiring natural frequency separation from known forcing frequencies, as well as explore an unexpected submerged brittle fracture failure mechanism, and how such issues may be avoided. (author)

Causes of bat fatalities at wind turbines: Hypotheses and predictions

Science.gov (United States)

Cryan, P.M.; Barclay, R.M.R.

2009-01-01

Thousands of industrial-scale wind turbines are being built across the world each year to meet the growing demand for sustainable energy. Bats of certain species are dying at wind turbines in unprecedented numbers. Species of bats consistently affected by turbines tend to be those that rely on trees as roosts and most migrate long distances. Although considerable progress has been made in recent years toward better understanding the problem, the causes of bat fatalities at turbines remain unclear. In this synthesis, we review hypothesized causes of bat fatalities at turbines. Hypotheses of cause fall into 2 general categoriesproximate and ultimate. Proximate causes explain the direct means by which bats die at turbines and include collision with towers and rotating blades, and barotrauma. Ultimate causes explain why bats come close to turbines and include 3 general types: random collisions, coincidental collisions, and collisions that result from attraction of bats to turbines. The random collision hypothesis posits that interactions between bats and turbines are random events and that fatalities are representative of the bats present at a site. Coincidental hypotheses posit that certain aspects of bat distribution or behavior put them at risk of collision and include aggregation during migration and seasonal increases in flight activity associated with feeding or mating. A surprising number of attraction hypotheses suggest that bats might be attracted to turbines out of curiosity, misperception, or as potential feeding, roosting, flocking, and mating opportunities. Identifying, prioritizing, and testing hypothesized causes of bat collisions with wind turbines are vital steps toward developing practical solutions to the problem. ?? 2009 American Society of Mammalogists.

Rotary piston blood pumps: past developments and future potential of a unique pump type.

Science.gov (United States)

Wappenschmidt, Johannes; Autschbach, Rüdiger; Steinseifer, Ulrich; Schmitz-Rode, Thomas; Margreiter, Raimund; Klima, Günter; Goetzenich, Andreas

2016-08-01

The design of implantable blood pumps is either based on displacement pumps with membranes or rotary pumps. Both pump types have limitations to meet the clinical requirements. Rotary piston blood pumps have the potential to overcome these limitations and to merge the benefits. Compared to membrane pumps, they are smaller and with no need for wear-affected membranes and valves. Compared to rotary pumps, the blood flow is pulsatile instead of a non-physiological continuous flow. Furthermore, the risk of flow-induced blood damage and platelet activation may be reduced due to low shear stress to the blood. The past developments of rotary piston blood pumps are summarized and the main problem for long-term application is identified: insufficient seals. A new approach with seal-less drives is proposed and current research on a simplified rotary piston design is presented. Expert commentary: The development of blood pumps focuses mainly on the improvement of rotary pumps. However, medical complications indicate that inherent limitations of this pump type remain and restrict the next substantial step forward in the therapy of heart failure patients. Thus, research on different pump types is reasonable. If the development of reliable drives and bearings succeeds, rotary piston blood pumps become a promising alternative.

Application of a generic superstructure-based formulation to the design of wind-pumped-storage hybrid systems on remote islands

International Nuclear Information System (INIS)

Chen, Cheng-Liang; Chen, Hui-Chu; Lee, Jui-Yuan

2016-01-01

Highlights: • A rigorous model for hybrid power system (HPS) design to support a remote island. • Use pumped hydro storage to store tentative surplus electricity. • Formulate the HPS design problem as a mixed-integer linear program (MILP). - Abstract: This paper aims to present a mathematical model for the design of a hybrid power system (HPS) to support a remote island with 100 thousand citizens. The goal is to reduce diesel fuel consumption by adequate expansion of wind power supply. Pumped hydroelectric storage (PHS) is used in the HPS to buffer the impact of intermittent behavior of wind energy. A superstructure is proposed for HPS design, considering all possible capital decisions (e.g. the number of wind turbines) and hourly-basis operational variables (such as the amount of surplus electricity in storage and its discharge). The HPS design problem can then be formulated as a mixed-integer linear program (MILP) based on the proposed superstructure. For a given total share of wind power, the optimal mix of diesel-based and wind power supplies as well as the required capacity of PHS are determined using a four-step optimization approach, involving minimizing (i) the consumption of diesel fuel, (ii) the number of wind turbines, (iii) the size of the upper water reservoir, and (iv) the charge/discharge rates of the PHS system. In this sequential optimization, the objective value obtained in a previous step is added as an additional constraint to the next step. The proposed HPS design model is applied to a real case study of the remote K Island on the other side of Taiwan Strait using hourly-basis, year-round historical data. Inclusion of other renewable energy sources, such as photovoltaic cells and biomass-fired power plants, as well as economic perspectives will be considered in future work.

Wind Turbines as Landscape Impediments to the Migratory Connectivity of Bats

Science.gov (United States)

Cryan, Paul M.

2011-01-01

Unprecedented numbers of migratory bats are found dead beneath industrial-scale wind turbines during late summer and autumn in both North America and Europe. Prior to the wide-scale deployment of wind turbines, fatal collisions of migratory bats with anthropogenic structures were rarely reported and likely occurred very infrequently. There are no other well-documented threats to populations of migratory tree bats that cause mortality of similar magnitude to that observed at wind turbines. Just three migratory species comprise the vast majority of bat kills at turbines in North America and there are indications that turbines may actually attract migrating individuals toward their blades. Although fatality of certain migratory species is consistent in occurrence across large geographic regions, fatality rates differ across sites for reasons mostly unknown. Cumulative fatality for turbines in North America might already range into the hundreds of thousands of bats per year. Research into the causes of bat fatalities at wind turbines can ascertain the scale of the problem and help identify solutions. None of the migratory bats known to be most affected by wind turbines are protected by conservation laws, nor is there a legal mandate driving research into the problem or implementation of potential solutions.

Proposed Wind Turbine Aeroelasticity Studies Using Helicopter Systems Analysis

Science.gov (United States)

Ladkany, Samaan G.

1998-01-01

Advanced systems for the analysis of rotary wing aeroelastic structures (helicopters) are being developed at NASA Ames by the Rotorcraft Aeromechanics Branch, ARA. The research has recently been extended to the study of wind turbines, used for electric power generation Wind turbines play an important role in Europe, Japan & many other countries because they are non polluting & use a renewable source of energy. European countries such as Holland, Norway & France have been the world leaders in the design & manufacture of wind turbines due to their historical experience of several centuries, in building complex wind mill structures, which were used in water pumping, grain grinding & for lumbering. Fossil fuel cost in Japan & in Europe is two to three times higher than in the USA due to very high import taxes. High fuel cost combined with substantial governmental subsidies, allow wind generated power to be competitive with the more traditional sources of power generation. In the USA, the use of wind energy has been limited mainly because power production from wind is twice as expensive as from other traditional sources. Studies conducted at the National Renewable Energy Laboratories (NREL) indicate that the main cost in the production of wind turbines is due to the materials & the labor intensive processes used in the construction of turbine structures. Thus, for the US to assume world leadership in wind power generation, new lightweight & consequently very flexible wind turbines, that could be economically mass produced, would have to be developed [4,5]. This effort, if successful, would result in great benefit to the US & the developing nations that suffer from overpopulation & a very high cost of energy.

Central Control of Heat Pump for Smart Grid Purposes Tested on Single Family Houses

DEFF Research Database (Denmark)

Pedersen, Tom S.; Andersen, Palle; Nielsen, Kirsten M.

2013-01-01

A challenge in Denmark in the near future is to balance the electrical grid due to a large increase in the renewable energy production mainly from wind turbines. In this work a central control system using heat pumps in single family houses to help balancing the grid is investigated. The central...

Steam turbines of large output especially for nuclear power stations. Part 1

International Nuclear Information System (INIS)

Drahny, J.; Stasny, M.

1986-01-01

At the international conference, 53 papers were presented in 3 sessions dealing with the design of large output steam turbines, with problems of flow in steam turbines, and with the reliability and service life of steam turbines. Part 1 of the conference proceedings contains two introductory papers, one reviewing the 100 years history of steam turbines (not included in INIS), the other giving an overview of the development of steam turbines in the eighties; and the 13 papers heard in the session on steam turbine design, all inputted in INIS. (A.K.)

Energy efficiency in pumps

International Nuclear Information System (INIS)

Kaya, Durmus; Yagmur, E. Alptekin; Yigit, K. Suleyman; Kilic, Fatma Canka; Eren, A. Salih; Celik, Cenk

2008-01-01

In this paper, 'energy efficiency' studies, done in a big industrial facility's pumps, are reported. For this purpose; the flow rate, pressure and temperature have been measured for each pump in different operating conditions and at maximum load. In addition, the electrical power drawn by the electric motor has been measured. The efficiencies of the existing pumps and electric motor have been calculated by using the measured data. Potential energy saving opportunities have been studied by taking into account the results of the calculations for each pump and electric motor. As a conclusion, improvements should be made each system. The required investment costs for these improvements have been determined, and simple payback periods have been calculated. The main energy saving opportunities result from: replacements of the existing low efficiency pumps, maintenance of the pumps whose efficiencies start to decline at certain range, replacements of high power electric motors with electric motors that have suitable power, usage of high efficiency electric motors and elimination of cavitation problems

Operating pumps on minimum flow

International Nuclear Information System (INIS)

Casada, D.A.; Li, Y.C.

1992-01-01

The Nuclear Regulatory Commission (NRC) staff issued Information Notice (IN) 87-59 to alert all licensees to two miniflow design concerns identified by Westinghouse. The first potential problem discussed in this IN involves parallel pump operation. If the head/capacity curve of one of the parallel pumps is greater than the other, the weaker pump may be dead-headed when the pumps are operating at low-flow conditions. The other problem related to potential pump damage as a result of hydraulic instability during low-flow operation. In NRC Bulletin 88-04, dated May 5, 1988, the staff requested all licensees to investigate and correct, as applicable, the two miniflow design concerns. The staff also developed a Temporary Instruction, Tl 2515/105, dated January 29, 1990 to inspect for the adequacy of licensee response and follow-up actions to NRC Bulletin 88-04. Oak Ridge National Laboratory has reviewed utility responses to Bulletin 88-04 under auspices of the NRC's Nuclear Plant Aging Research Program, and participated in several NRC inspections. Examples of actions that have been taken, an assessment of the overall industry response, and resultant conclusions and recommendations are presented

BWR recirculation pump diagnostic expert system

International Nuclear Information System (INIS)

Chiang, S.C.; Morimoto, C.N.; Torres, M.R.

2004-01-01

At General Electric (GE), an on-line expert system to support maintenance decisions for BWR recirculation pumps for nuclear power plants has been developed. This diagnostic expert system is an interactive on-line system that furnishes diagnostic information concerning BWR recirculation pump operational problems. It effectively provides the recirculation pump diagnostic expertise in the plant control room continuously 24 hours a day. The expert system is interfaced to an on-line monitoring system, which uses existing plant sensors to acquire non-safety related data in real time. The expert system correlates and evaluates process data and vibration data by applying expert rules to determine the condition of a BWR recirculation pump system by applying knowledge based rules. Any diagnosis will be automatically displayed, indicating which pump may have a problem, the category of the problem, and the degree of concern expressed by the validity index and color hierarchy. The rules incorporate the expert knowledge from various technical sources such as plant experience, engineering principles, and published reports. These rules are installed in IF-THEN formats and the resulting truth values are also expressed in fuzzy terms and a certainty factor called a validity index. This GE Recirculation Pump Expert System uses industry-standard software, hardware, and network access to provide flexible interfaces with other possible data acquisition systems. Gensym G2 Real-Time Expert System is used for the expert shell and provides the graphical user interface, knowledge base, and inference engine capabilities. (author)

Gas turbine

International Nuclear Information System (INIS)

Yang, Ok Ryong

2004-01-01

This book introduces gas turbine cycle explaining general thing of gas turbine, full gas turbine cycle, Ericson cycle and Brayton cycle, practical gas turbine cycle without pressure loss, multiaxial type gas turbine cycle and special gas turbine cycle, application of basic theory on a study on suction-cooling gas turbine cycle with turbo-refrigerating machine using the bleed air, and general performance characteristics of the suction-cooling gas turbine cycle combined with absorption-type refrigerating machine.

Pumping potential wells

International Nuclear Information System (INIS)

Hershkowitz, N.; Forest, C.; Wang, E.Y.; Intrator, T.

1987-01-01

Nonmonotonic plasma potential structures are a common feature of many double layers and sheaths. Steady state plasma potential wells separating regions having different plasma potentials are often found in laboratory experiments. In order to exist, such structures all must find a solution to a common problem. Ions created by charge exchange or ionization in the region of the potential well are electrostatically confined and tend to accumulate and fill up the potential well. The increase in positive charge should eliminate the well, but steady state structures are found in which the wells do not fill up. This means that it is important to take into account processes which 'pump' ions from the well. As examples of ion pumping of plasma wells, potential dips in front of a positively biased electron collecting anode in a relatively cold, low density multidipole plasma are considered. Pumping is provided by ion leaks from the edges of the potential dip or by oscillating the applied potential. In the former case the two dimensional character of the problem is shown to be important. (author)

Pumping potential wells

Science.gov (United States)

Hershkowitz, N.; Forest, C.; Wang, E. Y.; Intrator, T.

1987-01-01

Nonmonotonic plasma potential structures are a common feature of many double layers and sheaths. Steady state plasma potential wells separating regions having different plasma potentials are often found in laboratory experiments. In order to exist, such structures all must find a solution to a common problem. Ions created by charge exchange or ionization in the region of the potential well are electrostatically confined and tend to accumulate and fill up the potential well. The increase in positive charge should eliminate the well. Nevertheless, steady state structures are found in which the wells do not fill up. This means that it is important to take into account processes which 'pump' ions from the well. As examples of ion pumping of plasma wells, potential dips in front of a positively biased electro collecting anode in a relatively cold, low density multidipole plasma is considered. Pumping is provided by ion leaks from the edges of the potential dip or by oscillating the applied potential. In the former case the two dimensional character of the problem is shown to be important.

Pumping potential wells

International Nuclear Information System (INIS)

Hershkowitz, N.; Forest, C.; Wang, E.Y.; Intrator, T.

1987-01-01

Nonmonotonic plasma potential structures are a common feature of many double layers and sheaths. Steady state plasma potential wells separating regions having different plasma potentials are often found in laboratory experiments. In order to exist, all such structures must find a solution to a common problem. Ions created by charge exchange or ionization in the region of the potential well are electrostatically confined and tend to accumulate and fill up the potential well. The increase in positive charge should eliminate the well. Nevertheless, steady state structures are found in which the wells do not fill up. This means that it is important to take into account processes which pump ions from the well. As examples of ion pumping of plasma wells, potential dips in front of a positively biased electron collecting anode in a relatively cold, low density, multidipole plasma are considered. Pumping is provided by ion leaks from the edges of the potential dip or by oscillating the applied potential. In the former case the two-dimensional character of the problem is shown to be important

A parabolic velocity-decomposition method for wind turbines

Science.gov (United States)

Mittal, Anshul; Briley, W. Roger; Sreenivas, Kidambi; Taylor, Lafayette K.

2017-02-01

An economical parabolized Navier-Stokes approximation for steady incompressible flow is combined with a compatible wind turbine model to simulate wind turbine flows, both upstream of the turbine and in downstream wake regions. The inviscid parabolizing approximation is based on a Helmholtz decomposition of the secondary velocity vector and physical order-of-magnitude estimates, rather than an axial pressure gradient approximation. The wind turbine is modeled by distributed source-term forces incorporating time-averaged aerodynamic forces generated by a blade-element momentum turbine model. A solution algorithm is given whose dependent variables are streamwise velocity, streamwise vorticity, and pressure, with secondary velocity determined by two-dimensional scalar and vector potentials. In addition to laminar and turbulent boundary-layer test cases, solutions for a streamwise vortex-convection test problem are assessed by mesh refinement and comparison with Navier-Stokes solutions using the same grid. Computed results for a single turbine and a three-turbine array are presented using the NREL offshore 5-MW baseline wind turbine. These are also compared with an unsteady Reynolds-averaged Navier-Stokes solution computed with full rotor resolution. On balance, the agreement in turbine wake predictions for these test cases is very encouraging given the substantial differences in physical modeling fidelity and computer resources required.

Flashback mechanisms in lean premixed gas turbine combustion

CERN Document Server

Benim, Ali Cemal

2014-01-01

Blending fuels with hydrogen offers the potential to reduce NOx and CO2 emissions in gas turbines, but doing so introduces potential new problems such as flashback.  Flashback can lead to thermal overload and destruction of hardware in the turbine engine, with potentially expensive consequences. The little research on flashback that is available is fragmented. Flashback Mechanisms in Lean Premixed Gas Turbine Combustion by Ali Cemal Benim will address not only the overall issue of the flashback phenomenon, but also the issue of fragmented and incomplete research.Presents a coherent review of f

Remote condition-based monitoring of turbines

International Nuclear Information System (INIS)

2005-01-01

'Full text:' Turbines are one of the most expensive and critical pieces of equipment at a power generation facility. With high pressure stages that operate at up to 3500 psi and turn at speeds of up to 3600 rpm, minimal shaft misalignment, bearing wear, or other part breakdown can have catastrophic results. The results can include significant consequential damage to the turbine and other nearby equipment, extensive downtime for repair and purchase of replacement power, and potentially injury or death. Due to these enormous risks, virtually all turbines have built-in protection systems (e.g., Bentley Neveda, Vibro-Meter, etc.). These systems typically monitor peak-to-peak displacement of the shaft with proximity probes. Proximity probes monitor the relative motion between the shaft and the bearings. When the peak-to-peak motion exceeds a predetermined value (e.g., max peak of 7-10 mils) the protection device immediately sends a signal to shutdown the turbine. This may happen without warning, but more often there is an impending failure that develops over time from a degrading part or component. The part or component will almost invariably create abnormal movement in the system, resulting in a noticeable and detectable change in the equipment signatures (e.g., vibration, shaft 'orbit,' DC gap voltage). The protection devices usually provide information on the overall vibration trend of the turbine. While knowing the overall vibration within the system is a valuable metric, it has limited value as a diagnostic tool. It is the equivalent of a cardiologist having access only to a patient's pulse rate. The pulse rate may be significantly above normal, but - without more data - the cardiologist knows little more than that there is an impending problem. To better diagnose impending problems with a turbine, the following parameters are key: Vibration Trend: The vibration experienced by the shaft as a function of time; Spectrum: Displacement as a function of frequency at a

Applications of aero-acoustic analysis to wind turbine noise control

International Nuclear Information System (INIS)

Lowson, M.V.

1992-01-01

Wind turbine noise generation mechanisms are essentially equivalent to the aero-acoustic mechanisms of other rotors, which have been studied in depth for many years. Basic sources for the wind turbine noise radiation process are defined, and their significance assessed. From the analysis, areas of potential improvement in wind turbine noise prediction are defined. Suggestions are made for approaches to wind turbine noise control which separate the noise problems at cut-in from those at rated power. Some of these offer the possibility of noise reduction without unfavourable effects on performance. (author)

Applications of aero-acoustic analysis to wind turbine noise control

International Nuclear Information System (INIS)

Lowson, M.

1993-01-01

Wind turbine noise generation mechanisms are essentially equivalent to the aero-acoustic mechanisms of other rotors, which have been studied in depth for many years. Basic sources for the wind turbine noise radiation process are defined, and their significance assessed. From the analysis, areas of potential improvement in wind turbine noise prediction are defined. Suggestions are made for approaches to wind turbine noise control which separate the noise problems at cut-in from those at rated power. Some of these offer the possibility of noise reduction without unfavourable effects on performance. (author)

A contribution to water hammer analysis in pumped-storage power plants; Ein Beitrag zur Druckstossberechnung von Pumpspeicheranlagen

Energy Technology Data Exchange (ETDEWEB)

Hoeller, Stefan; Jaberg, Helmut [TU Graz (Austria). Inst. fuer Hydraulische Stroemungsmaschinen

2013-03-01

The operation of pumped-storage power plants induces a highly transient fluid flow in the penstock of high head water power plants. In the planning phase a reliable prediction of the transient plant behaviour in unsteady load cases such as e.g. machine start or switching load cases is necessary. Numerical simulation methods provide a tool to calculate the occurring pressure pulsations or mass oscillations as well as for the optimization of the transient behaviour. Commercial software-packages for water hammer simulations usually do not provide numerical models for a realistic calculation of complex components like surge tanks, turbines or emergency closing valves in a high head water power plant. But especially these components need to be modelled correctly in order to get a significant and reliable solution. This article shows the practice ofthe development of a custom-designed numerical model on the example of a pump turbine. (orig.)

CRBRP sodium circulating pump design evaluation

International Nuclear Information System (INIS)

Marrujo, F.; Cook, M.; Manners, L.; Cothran, H.

1977-12-01

The following topics are discussed: (1) primary sodium pump design concept; (2) pump level control system; (3) resolution of design problems in stress analysis, dynamics analysis, and mechanical design; (4) model testing; (5) planned performance tests; and (6) fabrication status

Offshore wind turbines reliability, availability and maintenance

CERN Document Server

Tavner, Peter

2012-01-01

The first book to specifically focus on offshore wind turbine technology and which addresses practically wind turbine reliability and availability. The book draws on the author's experience of power generation reliability and availability and the condition monitoring of that plant to describe the problems facing the developers of offshore wind farms and the solutions available to them to raise availability, reduce cost of energy and improve through life cost.

Maintenance of reactor recirculation pumps [Paper No.: II-1

International Nuclear Information System (INIS)

Ansari, M.A.; Bhat, K.P.

1981-01-01

At Tarapur Atomic Power Station (TAPS), two reactor recirculation pumps are provided, one each for the two reactor units. The performance of pumps has been uniformly good; however, leakage through the cartridge type, two stage, mechanical seals which are installed on these pumps was encountered on few occasions. The paper describes the leakage problems, identification of certain design deficiencies and rectification carried out at TAPS for overcoming these problems. (author)

Self-validated calculation of characteristics of a Francis turbine and the mechanism of the S-shape operational instability

International Nuclear Information System (INIS)

Zhang, Z; Titzschkau, M

2012-01-01

A calculation method has been presented to accurately estimate the characteristics of a Francis turbine. Both the shock loss at the impeller inlet and the swirling flow loss at the Impeller exit have been confirmed to dominantly influence the turbine characteristics and particularly the hydraulic efficiency. Both together totally govern the through flow of water through the impeller being at the rest. Calculations have been performed for the flow rate, the shaft torque and the hydraulic efficiency and compared with the available measurements on a model turbine. Excellent agreements have been achieved. Some other interesting properties of the turbine characteristics could also be derived from the calculations and verified by experiments. For this reason and because of not using any unreliable assumptions the calculation method has been confirmed to be self-validated. The operational instability in the upper range of the rotational speed, known as the S-shape instability, is ascribed to the total flow separation and stagnation at the impeller inlet. In that range of the rotational speed, the operation of the Francis turbine oscillates between pump and turbine mode.

Studies and solutions of steam turbines for nuclear heating power stations

International Nuclear Information System (INIS)

Drahy, J.

1979-01-01

The possibilities of combined generation of heat and electric power and special features of the corresponding equipment for WWER type reactors are considered. Condensing steam turbines with bled steam points and the constructional solution of bled points are presented for heating the network water to 110 0 C, 120 0 C, and 160 0 C, respectively. The dimensions of the low pressure final stage of the turbine are given. Problems concerning condensing and bleeding turbines and combination types of back-pressure and condensing turbines as well as solutions to the design of 250 MW and 500 MW turbines are discussed

ORCENT-2, Full Load Steam Turbine Cycle Thermodynamics for LWR Power Plant

International Nuclear Information System (INIS)

Fuller, L.C.

1979-01-01

1 - Description of problem or function: ORCENT-2 performs heat and mass balance calculations at valves-wide-open design conditions, maximum guaranteed rating conditions, and an approximation of part-load conditions for steam turbine cycles supplied with throttle steam, characteristic of contemporary light-water reactors. The program handles both condensing and back-pressure turbine exhaust arrangements. Turbine performance calculations are based on the General Electric Company method for 1800-rpm large steam turbine- generators operating with light-water-cooled nuclear reactors. Output includes all information normally shown on a turbine-cycle heat balance diagram. 2 - Method of solution: The turbine performance calculations follow the procedures outlined in General Electric report GET-6020. ORCENT-2 utilizes the 1967 American Society of Mechanical Engineers (ASME) formulations and procedures for calculating the properties of steam, adapted for ORNL use by D.W. Altom. 3 - Restrictions on the complexity of the problem: Maxima of: 12 feed-water heaters, 5 moisture removal stages in the low-pressure turbine section. ORCENT-2 is limited to 1800-rpm tandem-compound turbine-generators with single- or double-flow high pressure sections and one, two, or three double-flow low-pressure turbine sections. Steam supply for LWR cycles should be between 900 and 1100 psia and slightly wet to 100 degrees F of initial superheat. Generator rating should be greater than 100 MVA

Use of cooling ponds and hydraulic turbines to save SRP energy consumption

International Nuclear Information System (INIS)

Price, J.B.

1980-01-01

A substantial amount of energy can be saved by using cooling ponds to supply C and K reactors with cooling water. Hydraulic turbines between the reactor and the cooling pond can recover some of the power used to pump cooling water to the reactors. Cooling ponds would also reduce effluent temperature in the swamps adjacent to the Savannah River. Cooling ponds are evaluated in this memorandum

The marriage of gas turbines and coal

International Nuclear Information System (INIS)

Bajura, R.A.; Webb, H.A.

1991-01-01

This paper reports on developing gas turbine systems that can use coal or a coal-based fuel ensures that the United States will have cost-effective environmentally sound options for supplying future power generation needs. Power generation systems that marry coal or a coal-based fuel to a gas turbine? Some matchmakers would consider this an unlikely marriage. Historically, most gas turbines have been operated only on premium fuels, primarily natural gas or distillate oil. The perceived problems from using coal or coal-based fuels in turbines are: Erosion and deposition: Coal ash particles in the hot combustion gases passing through the expander turbine could erode or deposit on the turbine blades. Corrosion: Coal combustion will release alkali compounds form the coal ash. Alkali in the hot gases passing through the expander turbine can cause corrosion of high-temperature metallic surfaces. Emissions: coal contains higher levels of ash, fuel-bound sulfur and nitrogen compounds, and trace contaminants than premium fuels. Meeting stringent environmental regulations for particulates, sulfur dioxide (SO 2 ), nitrogen oxides (NO x ), and trace contaminants will be difficult. Economics: Coal-based systems are expensive to build. The difference in price between coal and premium fuels must be large enough to justify the higher capital cost

Preliminary Two-Phase Terry Turbine Nozzle Models for RCIC Off-Design Operation Conditions

Energy Technology Data Exchange (ETDEWEB)

Zhao, Haihua [Idaho National Lab. (INL), Idaho Falls, ID (United States); O' Brien, James [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2017-06-12

This report presents the effort to extend the single-phase analytical Terry turbine model to cover two-phase off-design conditions. The work includes: (1) adding well-established two-phase choking models – the Isentropic Homogenous Equilibrium Model (IHEM) and Moody’s model, and (2) theoretical development and implementation of a two-phase nozzle expansion model. The two choking models provide bounding cases for the two-phase choking mass flow rate. The new two-phase Terry turbine model uses the choking models to calculate the mass flow rate, the critical pressure at the nozzle throat, and steam quality. In the divergent stage, we only consider the vapor phase with a similar model for the single-phase case by assuming that the liquid phase would slip along the wall with a much slower speed and will not contribute the impulse on the rotor. We also modify the stagnation conditions according to two-phase choking conditions at the throat and the cross-section areas for steam flow at the nozzle throat and at the nozzle exit. The new two-phase Terry turbine model was benchmarked with the same steam nozzle test as for the single-phase model. Better agreement with the experimental data is observed than from the single-phase model. We also repeated the Terry turbine nozzle benchmark work against the Sandia CFD simulation results with the two-phase model for the pure steam inlet nozzle case. The RCIC start-up tests were simulated and compared with the single-phase model. Similar results are obtained. Finally, we designed a new RCIC system test case to simulate the self-regulated Terry turbine behavior observed in Fukushima accidents. In this test, a period inlet condition for the steam quality varying from 1 to 0 is applied. For the high quality inlet period, the RCIC system behaves just like the normal operation condition with a high pump injection flow rate and a nominal steam release rate through the turbine, with the net addition of water to the primary system; for

Floating axis wind turbines for offshore power generation—a conceptual study

International Nuclear Information System (INIS)

Akimoto, Hiromichi; Tanaka, Kenji; Uzawa, Kiyoshi

2011-01-01

The cost of energy produced by offshore wind turbines is considered to be higher than land based ones because of the difficulties in construction, operation and maintenance on offshore sites. To solve the problem, we propose a concept of a wind turbine that is specially designed for an offshore environment. In the proposed concept, a floater of revolutionary shape supports the load of the wind turbine axis. The floater rotates with the turbine and the turbine axis tilts to balance the turbine thrust, buoyancy and gravity. The tilt angle is passively adjustable to wind force. The angle is 30° at rated power. The simplicity of the system leads to further cost reduction of offshore power generation.

Steam turbines for nuclear power plants

International Nuclear Information System (INIS)

Stastny, M.

1983-01-01

A three-cylinder 220 MW saturated steam turbine was developed for WWER reactors by the Skoda concern. Twenty four of these turbines are currently in operation, in production or have been ordered. A 1000 MW four-cylinder turbine is being developed. The disign of the turbines has had to overcome difficulties connected with the unfavourable effects of wet steam at extreme power values. Great attention had to be devoted to the aerodynamics of control valves and to the prevention of flow separation areas. The problem of corrosion-erosion in guide wheels and the high pressure section was resolved by the use of ferritic stainless steels. For the low pressure section it was necessary to separate the moisture and to reheat the steam in the separator-reheater. Difficulties caused by the generation of wet steam in the low pressure section by spontaneous condensation were removed. Also limited was the erosion caused by droplets resulting from the disintegration of water films on the trailing edges. (A.K.)

Causes and proposed resolutions of high vibration in NWTF transfer pumps

International Nuclear Information System (INIS)

Trawinski, B.J.

1993-01-01

This Technical Report is intended to communicate the findings from the latest phase of New Waste Transfer Facility (NWTF) transfer pump testing. These tests have identified causes for the high pump vibrations that have been observed during previous phases of transfer pump startup testing, and have led to recommendations for resolving the vibration problem. The paper describes the problem, the test methodology, observations, and recommend actions to correct the vibration problem

Energy efficiency in pumps

Energy Technology Data Exchange (ETDEWEB)

Kaya, Durmus; Yagmur, E. Alptekin [TUBITAK-MRC, P.O. Box 21, 41470 Gebze, Kocaeli (Turkey); Yigit, K. Suleyman; Eren, A. Salih; Celik, Cenk [Engineering Faculty, Kocaeli University, Kocaeli (Turkey); Kilic, Fatma Canka [Department of Air Conditioning and Refrigeration, Kocaeli University, Kullar, Kocaeli (Turkey)

2008-06-15

In this paper, ''energy efficiency'' studies, done in a big industrial facility's pumps, are reported. For this purpose; the flow rate, pressure and temperature have been measured for each pump in different operating conditions and at maximum load. In addition, the electrical power drawn by the electric motor has been measured. The efficiencies of the existing pumps and electric motor have been calculated by using the measured data. Potential energy saving opportunities have been studied by taking into account the results of the calculations for each pump and electric motor. As a conclusion, improvements should be made each system. The required investment costs for these improvements have been determined, and simple payback periods have been calculated. The main energy saving opportunities result from: replacements of the existing low efficiency pumps, maintenance of the pumps whose efficiencies start to decline at certain range, replacements of high power electric motors with electric motors that have suitable power, usage of high efficiency electric motors and elimination of cavitation problems. (author)

Vacuum pumping for controlled thermonuclear reactors

International Nuclear Information System (INIS)

Watson, J.S.; Fisher, P.W.

1976-01-01

Thermonuclear reactors impose unique vacuum pumping problems involving very high pumping speeds, handling of hazardous materials (tritium), extreme cleanliness requirements, and quantitative recovery of pumped materials. Two principal pumping systems are required for a fusion reactor, a main vacuum system for evacuating the torus and a vacuum system for removing unaccelerated deuterium from neutral beam injectors. The first system must pump hydrogen isotopes and helium while the neutral beam system can operate by pumping only hydrogen isotopes (perhaps only deuterium). The most promising pumping techniques for both systems appear to be cryopumps, but different cryopumping techniques can be considered for each system. The main vacuum system will have to include cryosorption pumps cooled to 4.2 0 K to pump helium, but the unburned deuterium-tritium and other impurities could be pumped with cryocondensation panels (4.2 0 K) or cryosorption panels at higher temperatures. Since pumping speeds will be limited by conductance through the ducts and thermal shields, the pumping performance for both systems will be similar, and other factors such as refrigeration costs are likely to determine the choice. The vacuum pumping system for neutral beam injectors probably will not need to pump helium, and either condensation or higher temperature sorption pumps can be used

Calculation of the effects of pumping, divertor configuration and fueling on density limit in a tokamak model problem

International Nuclear Information System (INIS)

Stacey, W. M.

2001-01-01

Several series of model problem calculations have been performed to investigate the predicted effect of pumping, divertor configuration and fueling on the maximum achievable density in diverted tokamaks. Density limitations due to thermal instabilities (confinement degradation and multifaceted axisymmetric radiation from the edge) and to divertor choking are considered. For gas fueling the maximum achievable density is relatively insensitive to pumping (on or off), to the divertor configuration (open or closed), or to the location of the gas injection, although the gas fueling rate required to achieve this maximum achievable density is quite sensitive to these choices. Thermal instabilities are predicted to limit the density at lower values than divertor choking. Higher-density limits are predicted for pellet injection than for gas fueling

Canned motor pumps at Heavy Water Project, Baroda [Paper No.: II-2

International Nuclear Information System (INIS)

Batra, R.K.; Waishampayan, S.G.

1981-01-01

Heavy Water Project, Baroda is having special canned motor pumps for pumping ammonia and potassium amide. These pumps work under a pressure of 640 kg/cm 2 and are lubricated and cooled by the same fluid. These pumps are having special bearings consisting of mating surfaces of tungsten carbine Vs ceramic or stellite Vs carbon depending upon application. The total number of such pumps installed in the plant is around 52. These pumps being installed in high pressure vessels working at a pressure of 640 kg/cm 2 have special maintenance problems and need special care during maintenance. Pumps once boxed up are completely out of reach for immediate maintenance if needed. The failure of these pumps may mean a down time of one to two months for the plant. Besides above, there are multistage barrel type ammonia pumps with 24 stages developing a pressure of 140 kg/cm 2 . All these equipments need special maintenance methods as the problems faced are varied and difficult to solve. This paper deals with general and unique type of problems faced on these pumps. (author)

HEAT PUMP TECHNOLOGY – POTENTIAL IMPACT ON ENERGY EFFICIENCY PROBLEM AND CLIMATE ACTION GOALS WITHIN UKRAINIAN ENERGY SECTOR

Directory of Open Access Journals (Sweden)

O. Ostapenko

2015-12-01

Full Text Available The increasing demand of energy sources for urban, household and industrial facilities requires strategies development for seeking new energy sources. In recent years an important problem is to have energy storage, energy production and energy consumption which fulfill the environment friendly expectations. A lot of attention is devoted to renewable energy sources. One of the most attracting among them is energy production form geothermal sources. At a few meters below the earth’s surface the underground maintains a constant temperature in an approximation through the year allowing to withdraw heat in winter for heating needs and to surrender heat during summer for air-conditioning purposes. Heat pump is a rapidly developing technology for heating and domestic hot water production. Using ground as a heat source, heat exchange is carried out with heat pumps compound to vertical ground heat exchanger tubes that allows the heating and cooling of the buildings utilizing a single unit installation. Heat pump unit provides a high degree of productivity with moderate electric power consumption. In this paper a theoretical performance study of a vapor compression heat pump system with various natural and synthetic refrigerants (HFCs is presented. Operation mode of the heat pump unit was chosen according to European Standard EN14511-2:2007 and EN255-2. An influence of discharge temperature on system performance was evaluated at different boiling temperatures. The comparison of mass flow rate and coefficient of performance for considered refrigerants at constant cooling capacity and condensation temperature was performed.

垂直轴风力机直驱热泵压缩机匹配特性研究%Study on matching characteristics of vertical axis wind turbine direct-driven heat pump compressor/

Institute of Scientific and Technical Information of China (English)

赵斌; 马海鹏; 汪建文; 钟晓晖

2017-01-01

风能供热是多风寒冷地区,减少雾霾有效途径之一.针对垂直轴风力机直驱热泵压缩机系统,分析300W垂直轴风力机输出和开启式涡旋压缩机输入扭矩及功率特性,研究不同风速下垂直轴风力机与开启式涡旋压缩机特殊匹配特性.根据效率理论分析匹配特性,系统选型设计时垂直轴风力机输出功率应略高于压缩机所需输入功率,通过选择合理变速比,获得垂直轴风力机设计参数,实现系统按额定工况运行.为风能供热系统参数选型提供理论参考.%Wind energy heating was one of the effective ways to reduce haze in windy cold area.In view of the vertical axis wind turbines direct-drive heat pump compressor system,torque and power characteristics of the 300W vertical axis wind turbine output and opening scroll compressor input were analyzed.Special matching characteristics of opening scroll compressor was studied with the vertical axis wind turbines under different wind speed.In the selection design of the system,results showed that the efficiency of the device should be considered.The vertical axis wind turbine output power should be slightly higher than the compressor power input.Required vertical axis wind turbine design parameters could be obtained by selecting reasonable speed ratio,in order to make the system working in the rated conditions.Research results could lay theoretical basis for the parameter selection of wind energy heating system.

The aerodynamics of wind turbines

DEFF Research Database (Denmark)

Sørensen, Jens Nørkær; Mikkelsen, Robert Flemming; Troldborg, Niels

2013-01-01

In the paper we present state-of-the-art of research in wind turbine aerodynamics. We start be giving a brief historical review and a survey over aerodynamic research in wind energy. Next, we focus on some recent research results obtained by our wind energy group at Department of Mechanical...... Engineering at DTU. In particular, we show some new results on the classical problem of the ideal rotor and present a series of new results from an on-going research project dealing with the modelling and simulation of turbulent flow structures in the wake behind wind turbines....

ORTURB, HTGR Steam Turbine Dynamic for FSV Reactor

International Nuclear Information System (INIS)

Conklin, J.C.

2001-01-01

1 - Description of program or function: ORTURB was written specifically to calculate the dynamic behavior of the Fort St. Vrain (FSV) High- Temperature Gas-Cooled Reactor (HTGR) steam turbines. The program is divided into three main parts: the driver subroutine; turbine subroutines to calculate the pressure-flow balance of the high-, intermediate-, and low-pressure turbines; and feedwater heater subroutines. 2 - Method of solution: The program uses a relationship derived for ideal gas flow in an iterative fashion that minimizes computational time to determine the pressure and flow in the FSV steam turbines as a function of plant transient operating conditions. An important computer modeling characteristic, unique to FSV, is that the high-pressure turbine exhaust steam is used to drive the reactor core coolant circulators prior to entering the reheater. A feedwater heater dynamic simulation model utilizing seven state variables for each of the five heaters is included in the ORTURB computer simulation of the regenerative Rankine cycle steam turbines. The seven temperature differential equations are solved at each time- step using a matrix exponential method. 3 - Restrictions on the complexity of the problem: The turbine shaft is assumed to rotate at a constant (rated) speed of 3600 rpm. Energy and mass storage of steam in the high-, intermediate-, and low-pressure turbines is assumed to be negligible. These limitations exclude the use of ORTURB during a turbine transient such as startup from zero power or very low turbine flows

Detection of cavitation in hydraulic turbines

Science.gov (United States)

Escaler, Xavier; Egusquiza, Eduard; Farhat, Mohamed; Avellan, François; Coussirat, Miguel

2006-05-01

An experimental investigation has been carried out in order to evaluate the detection of cavitation in actual hydraulic turbines. The methodology is based on the analysis of structural vibrations, acoustic emissions and hydrodynamic pressures measured in the machine. The proposed techniques have been checked in real prototypes suffering from different types of cavitation. In particular, one Kaplan, two Francis and one Pump-Turbine have been investigated in the field. Additionally, one Francis located in a laboratory has also been tested. First, a brief description of the general features of cavitation phenomenon is given as well as of the main types of cavitation occurring in hydraulic turbines. The work presented here is focused on the most important ones which are the leading edge cavitation due to its erosive power, the bubble cavitation because it affects the machine performance and the draft tube swirl that limits the operation stability. Cavitation detection is based on the previous understanding of the cavity dynamics and its location inside the machine. This knowledge has been gained from flow visualisations and measurements in laboratory devices such as a high-speed cavitation tunnel and a reduced scale turbine test rig. The main techniques are the study of the high frequency spectral content of the signals and of their amplitude demodulation for a given frequency band. Moreover, low frequency spectral content can also be used in certain cases. The results obtained for the various types of cavitation found in the selected machines are presented and discussed in detail in the paper. Conclusions are drawn about the best sensor, measuring location, signal processing and analysis for each type of cavitation, which serve to validate and to improve the detection techniques.

Advanced Issues of Wind Turbine Modelling and Control

International Nuclear Information System (INIS)

Simani, Silvio

2015-01-01

The motivation for this paper comes from a real need to have an overview about the challenges of modelling and control for very demanding systems, such as wind turbine systems, which require reliability, availability, maintainability, and safety over power conversion efficiency. These issues have begun to stimulate research and development in the wide control community particularly for these installations that need a high degree of “sustainability”. Note that this topic represents a key point mainly for offshore wind turbines with very large rotors, since they are characterised by challenging modelling and control problems, as well as expensive and safety critical maintenance works. In this case, a clear conflict exists between ensuring a high degree of availability and reducing maintenance times, which affect the final energy cost. On the other hand, wind turbines have highly nonlinear dynamics, with a stochastic and uncontrollable driving force as input in the form of wind speed, thus representing an interesting challenge also from the modelling point of view. Suitable control methods can provide a sustainable optimisation of the energy conversion efficiency over wider than normally expected working conditions. Moreover, a proper mathematical description of the wind turbine system should be able to capture the complete behaviour of the process under monitoring, thus providing an important impact on the control design itself. In this way, the control scheme could guarantee prescribed performance, whilst also giving a degree of “tolerance” to possible deviation of characteristic properties or system parameters from standard conditions, if properly included in the wind turbine model itself. The most important developments in advanced controllers for wind turbines are addressed, and open problems in the areas of modelling of wind turbines are also outlined. (paper)

Noise annoyance from wind turbines a review

International Nuclear Information System (INIS)

Pedersen, Eja

2003-08-01

This study summarises present knowledge on noise perception and annoyances from wind turbines in areas were people live or spend recreation time. There are two main types of noise from a wind turbine: mechanical noise and aerodynamic noise. The aerodynamic noise emits from the rotor blades passing the air. It has a swishing character with a modulation that makes it noticeable from the background noise. This part of the wind turbine noise was found to be the most annoying. Field studies performed among people living in the vicinity of wind turbines showed that there was a correlation between sound pressure level and noise annoyance, but annoyance was also influenced by visual factors such as the attitude to wind turbines' impact on the landscape. Noise annoyance was found at lower sound pressure levels than in studies of annoyance from traffic noise. There is no scientific evidence that noise at levels created by wind turbines could cause health problems other than annoyance. No studies on noise from wind turbines in wilderness areas have been found, but the reaction to other noise sources such as aircraft have been studied. In recreational areas, the expectation of quietness is high among visitors, but wind turbines are, in contrary to aircraft, stationary and could be avoided by recreationists. The visual impact of wind turbines might though be the dominant source of annoyance. Regulations on noise from wind turbines are based on different principles. Some states, e.g. Denmark, have a special legislation concerning wind turbines, while others, like Sweden, have used recommendations originally developed for a different noise source. The noise level could either be absolute, as in Germany, or related to the background noise level as in France. This background noise level could be standardised, measured or related to wind speed

Potential of neuro-fuzzy methodology to estimate noise level of wind turbines

Science.gov (United States)

Nikolić, Vlastimir; Petković, Dalibor; Por, Lip Yee; Shamshirband, Shahaboddin; Zamani, Mazdak; Ćojbašić, Žarko; Motamedi, Shervin

2016-01-01

Wind turbines noise effect became large problem because of increasing of wind farms numbers since renewable energy becomes the most influential energy sources. However, wind turbine noise generation and propagation is not understandable in all aspects. Mechanical noise of wind turbines can be ignored since aerodynamic noise of wind turbine blades is the main source of the noise generation. Numerical simulations of the noise effects of the wind turbine can be very challenging task. Therefore in this article soft computing method is used to evaluate noise level of wind turbines. The main goal of the study is to estimate wind turbine noise in regard of wind speed at different heights and for different sound frequency. Adaptive neuro-fuzzy inference system (ANFIS) is used to estimate the wind turbine noise levels.

Danish wind power in Brazil. Part 2. Experience with Danish 75 kW wind turbine - the first modern turbine in Brazil

Energy Technology Data Exchange (ETDEWEB)

Husted Rich, N; Kildemoes Moeller, T

1996-04-01

In June of 1992, the first grid-connected wind turbine (75 kW, 12 m/s) in Brazil was installed in the complex terrain of the island of Fernando de Noronha in the northeastern part of the country. The objective was to install a Danish wind turbine in order to encourage the use of wind energy in Brazil and to demonstrate Danish wind technology with the view of opening up the Brazilian market for Danish windmills. It is claimed that the turbine, backed up by the media, attracted a certain amount of attention despite problems caused by the weakness of the electric grid on the island. The market in Brazil is still not ready for wind turbines and responsibility for any future wind energy policy is held by the political decision makers, so it is recommended that further demonstration projects be set up. The document presents a general view of the wind conditions and a view of the local electric power system with the aim of improving the potential for further installation of Danish wind turbines on the island. It proved difficult to obtain information on the performance of the windmill due to frequent rotations in the hierarchy of the state utility company CELPE, and the highly bureaucratic structure in general. It is stated that CELPE intends to install two more wind turbines on the island and that this could be a proof of recognition that technical problems that arose were caused by the unsatisfactory grid structure on the island and not related to faults in the wind turbine itself, and also a proof of their confidence in the idea of wind energy as a reliable source of electricity production. (AB)

Wind Turbine Generator Efficiency Based on Powertrain Combination and Annual Power Generation Prediction

Directory of Open Access Journals (Sweden)

Dongmyung Kim

2018-05-01

Full Text Available Wind turbine generators are eco-friendly generators that produce electric energy using wind energy. In this study, wind turbine generator efficiency is examined using a powertrain combination and annual power generation prediction, by employing an analysis model. Performance testing was conducted in order to analyze the efficiency of a hydraulic pump and a motor, which are key components, and so as to verify the analysis model. The annual wind speed occurrence frequency for the expected installation areas was used to predict the annual power generation of the wind turbine generators. It was found that the parallel combination of the induction motors exhibited a higher efficiency when the wind speed was low and the serial combination showed higher efficiency when wind speed was high. The results of predicting the annual power generation considering the regional characteristics showed that the power generation was the highest when the hydraulic motors were designed in parallel and the induction motors were designed in series.

The comparative analysis of model and prototype test results of Bulb turbine

International Nuclear Information System (INIS)

Benisek, M; Bozic, I; Ignjatovic, B

2010-01-01

This paper presents the problem of the hydropower plant oblique water inflow and its influence on the turbines operation. Oblique water inflow on the low head hydropower plant with bulb turbines influences turbine characteristics. The characteristics change occurs due to swirl incidence in the turbine inlet which spreads to the guide vanes inlet. Downstream, the flow conditions change is caused in the turbine runner in relation to the flow conditions without swirl inflow. Special attention is paid to the phenomenon of swirl flow incidence in the turbine conduit. With the aim of presenting and analyzing the oblique water inflow consequences on the hydropower plant operation, the existing turbine model tests results, performed in the laboratories, and the in situ prototype testing results have been used.

TurbinAID

International Nuclear Information System (INIS)

Moradian, M.A.; Chow, M.P.; Osborne, R.L.; Jenkins, M.A.

1991-01-01

The Westinghouse Turbine Artificial Intelligence Diagnostics system or TurbinAID, can diagnose both thermodynamic and mechanical component anomalies within the turbine, and around the turbine cycle. any monitoring system can detect that a variable is in an abnormal state, but TurbinAID can also indicate the cause, and provide recommended corrective action(s). The TurbinAID Expert Systems utilize multiple sensor and variable inputs, and their interdependencies in the generation of a diagnosis. The system performs sensor validation as part of the data acquisition scheme. The TurbinAID system has been in operation for several years. This paper describes the monitoring and diagnostic functions provided by TurbinAID, and how the utility industry both nuclear and fossil, can utilize the system to enhance unit operation

FY 1992 Report on results of the survey/research project commissioned by Sunshine Project. Surveys on hydrogen-fired turbines; 1992 nendo suiso nensho turbine no chosa seika hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1993-03-01

Summarized herein are results of comprehensive surveys on hydrogen energy supply/utilization systems, centered by hydrogen-fired turbines for power generation. The surveyed items include hydrogen energy supply/utilization systems on an international scale, current state of power generation techniques and utilization of hydrogen, hydrogen-fired turbines for power generation, materials techniques for hydrogen-fired turbines, studies on and evaluation of economic viability of each system, expected effects, and problems involved in development. The surveys on the hydrogen production techniques pick up electrolysis with a solid polymer electrolyte as a promising candidate, and extract the scaling-up techniques, improvement of membrane durability, etc. as the research themes. The surveys on the hydrogen storage/transportation techniques indicate that hydrogen can be carried by a chemical medium for transportation/storage at normal temperature and pressure, for which the problems associated with medium loss and safety must be studied, and that the research themes for hydrogen-occluding alloys should include increasing quantities of hydrogen occluded for bulk transportation/storage at low energy, and decreasing cost. The surveys on hydrogen-fired turbines extract a number of problems to be solved, e.g., controlling hydrogen combustion, turbine designs, materials withstanding superhigh temperature for high-temperature combustion of hydrogen, and optimization of the power generation systems. (NEDO)

Some features of the flow in the Holweck pump

OpenAIRE

Skovorodko, Petr A.

2004-01-01

Numerical algorithm for direct simulation of the gas flow in the Holweck pump is developed. The results illustrating the important features of the flow in the pump are reported. An attention is paid to the problem of the pump design optimization.

Vertical axis wind turbines : past initiatives and future prospects

Energy Technology Data Exchange (ETDEWEB)

Islam, M.; Fartaj, A.; Ting, D. [Windsor Univ., ON (Canada). Dept. of Mechanical, Automotive and Materials Engineering

2003-08-01

Horizontal Axis Wind Turbines (HAWT) and Vertical Axis Wind Turbines (VAWT) are the two categories of modern wind turbines used for producing electricity and pumping water. While their popularity declined in the 1970s and 1980s to more economical fossil fuel resources, many countries have expressed a renewed interest in wind power in response to environmental concerns and energy security. Renewable energy sources supply more than 14 per cent of the total global energy demand, and wind energy plays the biggest role. In 2002, more than $7 billion was invested in wind technology. Canada has been a leader in VAWT technology. In 1966, Engineers at the Low Speed Aerodynamics Laboratory of the National Research Council devised a VAWT configuration with non-adjustable hoop-shaped airfoils that had greater efficiency that conventional high-solidity VAWT. In the early 1980s, a multi-megawatt VAWT was built in Quebec under the auspices of the EOLE project. The EOLE is the largest VAWT in the world. In 1980, Canada's national Atlantic Wind Test Site was developed for the purpose of testing and developing wind technology. Research at this facility has focused on dynamically soft Darrieus rotors, a concept which can reduce structural loads. Early development has shown that although VAWT is slightly less efficient than HAWT, it can be built larger and more cost effectively. This paper presents the outstanding features of VAWT products including the Solwind SW 10/4800 series VAWT, the Chinook 2000 wind turbine, the Ropatec Windrotor, the Windside Turbine, the VAWTEX, the Windstar VAWT, and Windtec. 19 refs., 13 figs.

The design of wind turbine for electrical power generation in Malaysian wind characteristics

International Nuclear Information System (INIS)

Abas Ab Wahab; Chong Wen Thong

2000-01-01

The paper describes the study of a wind turbine for electrical power generation in Malaysia wind characteristics. In this research, the wind turbine is designs based on the local wind characteristics and tries to avoid the problems faced in the past (turbine design, access, manpower and technical). The new wind turbine rotor design for a medium speed wind speed turbine utilises the concept of open-close type of horizontal axis (up-wind) wind turbine is intended to widen the optimum performance range for electrical generation in Malaysia wind characteristics. The wind turbine has been designed to cut-in at a lower speed, and to provide the rotation speed that high enough to run a generator. The analysis and design of new low speed wind turbine blades and open-close turbine rotor and prediction of turbine performance are being detailed in this paper. (Author)

Heat exchangers for automotive gas turbine power plants

International Nuclear Information System (INIS)

Penny, R.N.

1974-01-01

Automotive gas turbine power plants are now in the final stages of development for quantity manufacture. A crucial factor in this development is the regenerative heat exchanger. The relative merits of the rotary regenerative and static recuperative heat exchanger are compared. Thermal efficiency and initial cost are two vital issues involved in the design of small gas turbines for the commercial establishment of gas turbine vehicles. The selection of a material for the rotaty regenerator is essentially related to resolving the two vital issues of future small gas turbines and is, therefore, analysed. The account of the pioneering work involved in engineering the glass ceramic and other non-metal regenerators includes a complete failure analysis based on running experience with over 200 ceramic regenerators. The problems of sealing, supporting and manufacturing the ceramic regenerator are discussed and future practical designs are outlined. Heat exchange theory applied to small gas turbines is also reviewed

Particulars in design of the electrical part of the Kiev Pumped-Storage Electric Power Plant

Energy Technology Data Exchange (ETDEWEB)

Brimerberg, V P

1976-01-01

The Kiev Pumped-Storage Electric Power Plant is the first such installation in the Soviet Union. The power capacity of the plant is 225 MW. There are six vertical hydraulic generators: three are connected to vertical pump-turbines and operate as motor-generators; the other three are connected to vertical radial-axial hydraulic turbines and operate as generators only. Each generator is a type SVO 733/130-36 with power of 45.6 MVA. The active power load is 83.5 MW, reactive--75.1, and total--112.5 MVA. The installation can be used for 500 h/yr at maximum power, producing 110 million kWh. During the high-water period, the plant is used daily for about 100 days, covering the peak of the load schedule of the southern power system. During the low-water period the plant is used as needed. During the slack hours at night the system operates in the pump mode for about 1400 h/yr, using 160 million kWh. During the remainder of the day the generators work as synchronous compensators with a total load on each of 36,500 kvar. Electrical circuits and a cross section of the generator are given. An explanation is also given of the grounding precautions taken to ensure an equipotential field at all points of the installation where personnel may be located.

Conceptual design and related R and D on ITER mechanical based primary pumping system

International Nuclear Information System (INIS)

Tanzawa, Sadamitsu; Hiroki, Seiji; Abe, Tetsuya; Shimizu, Katsusuke; Inoue, Masahiko; Watanabe, Mitsunori; Iguchi, Masashi; Sugimoto, Tomoko; Inohara, Takashi; Nakamura, Jun-ichi

2008-12-01

The primary vacuum pumping system of the International Thermonuclear Experimental Reactor (ITER) exhausts a helium (He) ash resulting from the DT-burn with excess DT fueling gas, as well as performing a variety of functions such as pump-down, leak testing and wall conditioning. A mechanical based vacuum pumping system has some merits of a continuous pumping, a much lower tritium inventory, a lower operational cost and easy maintenance, comparing with a cryopump system, although demerits of an indispensable magnetic shield and insufficient performance for hydrogen (H 2 ) pumping is are well recognized. To overcome the demerits, we newly fabricated and tested a helical grooved pump (HGP) unit suitable for H 2 pumping at the ITER divertor pressure of 0.1-10 Pa. Through this R and D, we successfully established many design and manufacturing databases of large HGP units for the lightweight gas pumping. Based on the databases, we conceptually designed the ITER vacuum pumping system mainly comprising the HGP with an optimal pump unit layout and a magnetic shield. We also designed conceptually the reduced cost (RC)-ITER pumping system, where a compound molecular pump combining turbine bladed rotors and helical grooved ones was mainly used. The ITER mechanical based primary pumping system proposed has eventually been a back-up solution, whereas a cryopump based one was formally selected to the ITER for construction. The mechanical pumps are increasingly used in many areas with well sophisticated performance, so we believe that fusion reactors of subsequent prototype ones will select the mechanical based pumping system due to primarily a high operational reliability and a cost melt. (author)

Study on gas turbines. Leading role of high efficiency power generation; Gas turbine kenkyu. Kokoritsu hatsuden no shuyaku wo nerau

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-01-31

This review summarizes research works of Central Research Institute of Electric Power Industry on gas turbines playing a leading role of high efficiency power generation. This article describes historical changes of gas turbine technology, changes and current status from the viewpoint of electric power industry, and development trend in various makers. Increase in the flow-in gas temperature, low NOx combustion technology, use of various fuels, and durability evaluation and improvement technology for high temperature parts are described as technological problems and development trends. The increase in temperature is indispensable for the improvement of efficiency. Materials having heat resistance, anticorrosion and strength are required. Accordingly, Ni-based single crystal super alloy has been developed. Developments of ceramic gas turbine and catalytic combustor are also described. The coal gasification combined power generation is expected as a new power generation technology having availability of various coals, high efficiency, and excellent environmental protection. Development of 1500 {degree}C class combustor for turbines has been promoted. Evaluation and improvement of durability of high temperature parts are also described. For the new utilization technology of gas turbines, repowering and compressed air storage gas turbine power generation technology are introduced. 92 figs., 14 tabs.

Helium gas turbine conceptual design by genetic/gradient optimization

International Nuclear Information System (INIS)

Yang, Long; Yu, Suyuan

2003-01-01

Helium gas turbine is the key component of the power conversion system for direct cycle High Temperature Gas-cooled Reactors (HTGR), of which an optimal design is essential for high efficiency. Gas turbine design currently is a multidisciplinary process in which the relationships between constraints, objective functions and variables are very noisy. Due to the ever-increasing complexity of the process, it has becomes very hard for the engineering designer to foresee the consequences of changing certain parts. With classic design procedures which depend on adaptation to baseline design, this problem is usually averted by choosing a large number of design variables based on the engineer's judgment or experience in advance, then reaching a solution through iterative computation and modification. This, in fact, leads to a reduction of the degree of freedom of the design problem, and therefore to a suboptimal design. Furthermore, helium is very different in thermal properties from normal gases; it is uncertain whether the operation experiences of a normal gas turbine could be used in the conceptual design of a helium gas turbine. Therefore, it is difficult to produce an optimal design with the general method of adaptation to baseline. Since their appearance in the 1970s, Genetic algorithms (GAs) have been broadly used in many research fields due to their robustness. GAs have also been used recently in the design and optimization of turbo-machines. Researchers at the General Electronic Company (GE) developed an optimization software called Engineous, and used GAs in the basic design and optimization of turbines. The ITOP study group from Xi'an Transportation University also did some work on optimization of transonic turbine blades. However, since GAs do not have a rigorous theory base, many problems in utilities have arisen, such as premature convergence and uncertainty; the GA doesn't know how to locate the optimal design, and doesn't even know if the optimal solution

Optimization of the operating conditions of gas-turbine power stations considering the effect of equipment deterioration

Science.gov (United States)

Aminov, R. Z.; Kozhevnikov, A. I.

2017-10-01

In recent years in most power systems all over the world, a trend towards the growing nonuniformity of energy consumption and generation schedules has been observed. The increase in the portion of renewable energy sources is one of the important challenges for many countries. The ill-predictable character of such energy sources necessitates a search for practical solutions. Presently, the most efficient method for compensating for nonuniform generation of the electric power by the renewable energy sources—predominantly by the wind and solar energy—is generation of power at conventional fossil-fuel-fired power stations. In Russia, this problem is caused by the increasing portion in the generating capacity structure of the nuclear power stations, which are most efficient when operating under basic conditions. Introduction of hydropower and pumped storage hydroelectric power plants and other energy-storage technologies does not cover the demand for load-following power capacities. Owing to a simple design, low construction costs, and a sufficiently high economic efficiency, gas turbine plants (GTPs) prove to be the most suitable for covering the nonuniform electric-demand schedules. However, when the gas turbines are operated under varying duty conditions, the lifetime of the primary thermostressed components is considerably reduced and, consequently, the repair costs increase. A method is proposed for determination of the total operating costs considering the deterioration of the gas turbine equipment under varying duty and start-stop conditions. A methodology for optimization of the loading modes for the gas turbine equipment is developed. The consideration of the lifetime component allows varying the optimal operating conditions and, in some cases, rejecting short-time stops of the gas turbine plants. The calculations performed in a wide range of varying fuel prices and capital investments per gas turbine equipment unit show that the economic effectiveness can

Micro-turbines

International Nuclear Information System (INIS)

Tashevski, Done

2003-01-01

In this paper a principle of micro-turbines operation, type of micro-turbines and their characteristics is presented. It is shown their usage in cogeneration and three generation application with the characteristics, the influence of more factors on micro-turbines operation as well as the possibility for application in Macedonia. The paper is result of the author's participation in the training program 'Micro-turbine technology' in Florida, USA. The characteristics of different types micro-turbines by several world producers are shown, with accent on US micro-turbines producers (Capstone, Elliott). By using the gathered Author's knowledge, contacts and the previous knowledge, conclusions and recommendations for implementation of micro-turbines in Macedonia are given. (Author)

Detection of pump degradation

International Nuclear Information System (INIS)

Greene, R.H.; Casada, D.A.; Ayers, C.W.

1995-08-01

This Phase II Nuclear Plant Aging Research study examines the methods of detecting pump degradation that are currently employed in domestic and overseas nuclear facilities. This report evaluates the criteria mandated by required pump testing at U.S. nuclear power plants and compares them to those features characteristic of state-of-the-art diagnostic programs and practices currently implemented by other major industries. Since the working condition of the pump driver is crucial to pump operability, a brief review of new applications of motor diagnostics is provided that highlights recent developments in this technology. The routine collection and analysis of spectral data is superior to all other technologies in its ability to accurately detect numerous types and causes of pump degradation. Existing ASME Code testing criteria do not require the evaluation of pump vibration spectra but instead overall vibration amplitude. The mechanical information discernible from vibration amplitude analysis is limited, and several cases of pump failure were not detected in their early stages by vibration monitoring. Since spectral analysis can provide a wealth of pertinent information concerning the mechanical condition of rotating machinery, its incorporation into ASME testing criteria could merit a relaxation in the monthly-to-quarterly testing schedules that seek to verify and assure pump operability. Pump drivers are not included in the current battery of testing. Operational problems thought to be caused by pump degradation were found to be the result of motor degradation. Recent advances in nonintrusive monitoring techniques have made motor diagnostics a viable technology for assessing motor operability. Motor current/power analysis can detect rotor bar degradation and ascertain ranges of hydraulically unstable operation for a particular pump and motor set. The concept of using motor current or power fluctuations as an indicator of pump hydraulic load stability is presented

Detection of pump degradation

Energy Technology Data Exchange (ETDEWEB)

Greene, R.H.; Casada, D.A.; Ayers, C.W. [and others

1995-08-01

This Phase II Nuclear Plant Aging Research study examines the methods of detecting pump degradation that are currently employed in domestic and overseas nuclear facilities. This report evaluates the criteria mandated by required pump testing at U.S. nuclear power plants and compares them to those features characteristic of state-of-the-art diagnostic programs and practices currently implemented by other major industries. Since the working condition of the pump driver is crucial to pump operability, a brief review of new applications of motor diagnostics is provided that highlights recent developments in this technology. The routine collection and analysis of spectral data is superior to all other technologies in its ability to accurately detect numerous types and causes of pump degradation. Existing ASME Code testing criteria do not require the evaluation of pump vibration spectra but instead overall vibration amplitude. The mechanical information discernible from vibration amplitude analysis is limited, and several cases of pump failure were not detected in their early stages by vibration monitoring. Since spectral analysis can provide a wealth of pertinent information concerning the mechanical condition of rotating machinery, its incorporation into ASME testing criteria could merit a relaxation in the monthly-to-quarterly testing schedules that seek to verify and assure pump operability. Pump drivers are not included in the current battery of testing. Operational problems thought to be caused by pump degradation were found to be the result of motor degradation. Recent advances in nonintrusive monitoring techniques have made motor diagnostics a viable technology for assessing motor operability. Motor current/power analysis can detect rotor bar degradation and ascertain ranges of hydraulically unstable operation for a particular pump and motor set. The concept of using motor current or power fluctuations as an indicator of pump hydraulic load stability is presented.

Tiny bubbles challenge giant turbines: Three Gorges puzzle.

Science.gov (United States)

Li, Shengcai

2015-10-06

Since the birth of the first prototype of the modern reaction turbine, cavitation as conjectured by Euler in 1754 always presents as a challenge. Following his theory, the evolution of modern reaction (Francis and Kaplan) turbines has been completed by adding the final piece of the element 'draft-tube' that enables turbines to explore water energy at efficiencies of almost 100%. However, during the last two and a half centuries, with increasing unit capacity and specific speed, the problem of cavitation has been manifested and complicated by the draft-tube surges rather than being solved. Particularly, during the last 20 years, the fierce competition in the international market for extremely large turbines with compact design has encouraged the development of giant Francis turbines of 700-1000 MW. The first group (24 units) of such giant turbines of 700 MW each was installed in the Three Gorges project. Immediately after commission, a strange erosion phenomenon appeared on the guide vane of the machines that has puzzled professionals. From a multi-disciplinary analysis, this Three Gorges puzzle could reflect an unknown type of cavitation inception presumably triggered by turbulence production from the boundary-layer streak transitional process. It thus presents a fresh challenge not only to this old turbine industry, but also to the fundamental sciences.

Improvement of seawater booster pump outlet check valve

International Nuclear Information System (INIS)

Li Xuning; Du Yansong; Huang Huimin

2010-01-01

Conventional island seawater booster pump set of QNPC 310 MWe unit are very important in the whole circulating cooling system, and the integrate function of seawater booster pump outlet check valve is the foundation of steady operation of the seawater booster pump set. The article mainly introduce that through the analyses to the reason to the problem that the seawater booster pump outlet check valve of QNPC 310 MWe unit appeared in past years by our team, and considering the influence of operation condition and circumstance, the team improve the seawater booster pump outlet check valve from swing check valve to shuttle check valve which operate more appropriately in the system. By the test of continuous practice, we make further modification to the inner structure of shuttle check valve contrapuntally, and therefore we solve the problem in seawater booster pump outlet check valve fundamentally which has troubled the security of system operation in past years, so we realize the aim of technical improvement and ensure that the system operate in safety and stability. (authors)

Mechanical problems in turbomachines, steam and gas turbines. Large steam turbine manufacturing requirements to fulfill customer needs for electric power

International Nuclear Information System (INIS)

Brazzini, R.

1975-01-01

The needs of the customers in large steam turbines for electric power are examined. The choices and decisions made by the utility about the equipments are dealt with after considering the evolution of power demand on the French network. These decisions and choices mainly result from a technical and economic optimization of production equipments: choice of field-proven solutions, trend to lower steam characteristics, trend to higher output of the units (i.e. size effect), spreading out standardization of machines and components (policy of technical as well as technological levels, i.e. mass production effect). Standardization of external characteristics of units of same level of output and even standardization of some main components. The requirements turbine manufacturers have to meet may fall in two categories: on one side: gaining experience and know-how, capability of making high quality experiments, out put capacity, will to hold a high efficiency level; on the other side: meeting the technical requirements related to the contracts. Among these requirements, one can differentiate those dealing with the service expected from the turbine and that resulting in the responsibility limits of the manufacturer and those tending to gain interchangeability, to improve availability of the equipment, to increase safety, and to make operation and maintenance easier [fr

Development of drag disk and turbines at the INEL

International Nuclear Information System (INIS)

Goodrich, L.D.; Edson, J.L.; Averill, R.H.

1984-01-01

One of the parameters that must be measured in nuclear safety research is mass flow rate. The reactor environment associated with two-phase flow makes this measurement difficult. To accomplish this at the Idaho National Engineering Laboratory, a drag disk and turbine transducer conbination was developed. These transducers can withstand >2000 h of continuous operation in the reactor environment. Mechanical problems have been solved with these transducers to the point where the electrical coils are now the limiting factor on lifetime. This paper presents the results of the development of the drag disk and turbine with problems and solutions pointed out

The Causes and Prevention Measures of Stuck Pump Phenomenon of Rod-pumped Well in CBM Field

Science.gov (United States)

Yonggui, Mei

2018-02-01

In the process of CBM field exploitation, in order to realize the drainage equipment to work continuous stably, the article pays attention to study and solve the stuck pump problem, and aim of reducing reservoir damage and lowing production costs. Through coal particles stuck pump experiment and sediment composition analysis, we find out five primary cause of stuck pump phenomenon: sand from coal seam, sediment from ground, iron corrosion, iron scrap caused by eccentric wear, coal cake. According to stuck pump mechanism, the article puts forward 8 measures to prevent stuck pump phenomenon, and the measures are focused on technology optimization, operation management and drainage process control. After 7 years production practice, the yearly stuck pump rate has dropped from 8.9% to 1.2%, and the pump inspection period has prolonged 2 times. The experiment result shows that pure coal particles cannot cause stuck pump, but sand, scrap iron, and iron corrosion are the primary cause of stuck pump. The article study and design the new pipe string structure that the bottom of the pipe string is open. This kind of pipe string applied the sedimentation terminal velocity theory to solve the stuck pump phenomenon, and it can be widely used in CBM drainage development.

Evaluation of pump characteristic from measurement of fast deceleration

Directory of Open Access Journals (Sweden)

Himr Daniel

2015-01-01

Full Text Available Article describes an experiment where a pump connected to the simple hydraulic circuit is decelerated. Since the deceleration is fast enough the operating point of the machine moves from the initial steady position to the breaking zone, turbine zone and back to the new steady position. A dependence of the specific energy and the torque on the flow rate was evaluated from the measurement of the input and output pressure, torque and rotational speed recorded during the deceleration. Obtained characteristic is much wider than curves obtained from regular measurement of steady state.

A novel technology for control of variable speed pumped storage power plant

Institute of Scientific and Technical Information of China (English)

Seyed Mohammad Hassan Hosseini; Mohammad Reza Semsar

2016-01-01

Variable speed pumped storage machines are used extensively in wind power plant and pumped storage power plant. This paper presents direct torque and flux control (DTFC) of a variable speed pumped storage power plant (VSPSP). By this method both torque and flux have been applied to control the VSPSP. The comparison between VSPSP’s control strategies is studied. At the first, a wind turbine with the capacity 2.2 kW and DTFC control strategies simulated then a 250 MW VSPSP is simulated with all of its parts (including electrical, mechanical, hydraulic and its control system) by MATLAB software. In all of simulations, both converters including two-level voltage source converter (2LVSC) and three-level voltage source converter (3LVSC) are applied. The results of applying 2LVSC and 3LVSC are the rapid dynamic responses with better efficiency, reducing the total harmonic distortion (THD) and ripple of rotor torque and flux.

Investigation of Pumped Storage Hydropower Power-Off Transient Process Using 3D Numerical Simulation Based on SP-VOF Hybrid Model

Directory of Open Access Journals (Sweden)

Daqing Zhou

2018-04-01

Full Text Available The transient characteristic of the power-off process is investigated due to its close relation to hydraulic facilities’ safety in a pumped storage hydropower (PSH. In this paper, power-off transient characteristics of a PSH station in pump mode was studied using a three-dimensional (3D unsteady numerical method based on a single-phase and volume of fluid (SP-VOF coupled model. The computational domain covered the entire flow system, including reservoirs, diversion tunnel, surge tank, pump-turbine unit, and tailrace tunnel. The fast changing flow fields and dynamic characteristic parameters, such as unit flow rate, runner rotate speed, pumping lift, and static pressure at measuring points were simulated, and agreed well with experimental results. During the power-off transient process, the PSH station underwent pump mode, braking mode, and turbine mode, with the dynamic characteristics and inner flow configurations changing significantly. Intense pressure fluctuation occurred in the region between the runner and guide vanes, and its frequency and amplitude were closely related to the runner’s rotation speed and pressure gradient, respectively. While the reversed flow rate of the PSH unit reached maximum, some parameters, such as static pressure, torque, and pumping lift would suddenly jump significantly, due to the water hammer effect. The moment these marked jumps occurred was commonly considered as the most dangerous moment during the power-off transient process, due to the blade passages being clogged by vortexes, and chaos pressure distribution on the blade surfaces. The results of this study confirm that 3D SP-VOF hybrid simulation is an effective method to reveal the hydraulic mechanism of the PSH transient process.

Resolution of torsional vibration issue for large turbine generators

International Nuclear Information System (INIS)

Evans, D.G.; Giesecke, H.D.; Willman, E.C.; Moffitt, S.P.

1995-01-01

The excitation of turbine generator torsional natural frequencies in the region near 120 Hz by electrical transients in the power system has resulted in blade failures for several large 1,800 rpm nuclear turbines. At Cleveland Electric's Perry Nuclear Power plant a combination of advanced measurement techniques and analyses were used to identify and resolve a potential torsional vibration problem without adverse impact on the plant availability. The Perry turbine generator consists of a high pressure turbine, three low pressure turbines with 43 inch last stage blades, and a 1,250 MWe four pole generator operating at 1,800 rpm. Torsional vibration measurements obtained from random vibration during operation were acquired just prior to the 1994 refueling outage. The measurements indicated that the 26th torsional mode of vibration was just under 120 Hz and within the range of frequencies for which the manufacturer recommends modifying the unit to shift the problem torsional natural frequency. Extensive analytical modeling was used to design a modification to shift the torsional natural frequencies away from 120 Hertz and the modification was implemented during the refueling outage without affecting outage critical path. An off-line ramp test and additional on-line monitoring performed at the conclusion of the outage confirmed that the on-line method provided accurate measurements of the torsional natural frequencies and demonstrated that, with the modification, the torsional natural frequencies were sufficiently removed from 120 Hertz to allow turbine generator operation. The modification, which involved brazing of the tie wires on all last stage blades, also significantly reduces the stress on the last stage blades that result from negative sequence currents, further increasing the operating margin of the turbine generator with respect to electrical transients and faults

Turbine stage model

International Nuclear Information System (INIS)

Kazantsev, A.A.

2009-01-01

A model of turbine stage for calculations of NPP turbine department dynamics in real time was developed. The simulation results were compared with manufacturer calculations for NPP low-speed and fast turbines. The comparison results have shown that the model is valid for real time simulation of all modes of turbines operation. The model allows calculating turbine stage parameters with 1% accuracy. It was shown that the developed turbine stage model meets the accuracy requirements if the data of turbine blades setting angles for all turbine stages are available [ru

Efficiency assessment of a wind pumping system

International Nuclear Information System (INIS)

Lara, David D.; Merino, Gabriel G.; Pavez, Boris J.; Tapia, Juan A.

2011-01-01

The combined efficiency of the components determines overall system performance in electric wind pumping systems. We evaluated a system composed of a 3 kW wind generator feeding a battery bank of 48 V/880 Ah by means of a non-controlled 6-pulse rectifier. Connected to this battery bank was a 1.5 kW inverter that generated 220 V at 50 Hz, which powers a 1.1 kW single-phase electric pump. At the University of Concepcion, Chile, energy losses in each electrical component was determined using a data collection system configured to measure electrical variables in real time. The electrical power generated by the wind generator for different wind speeds averaged 38% lower than the power curve provided by the manufacturer. Electromechanical tests performed in a lab showed the operation efficiency of the electric generator of the wind turbine averaged 80%. This information, along with the electrical power output, and the wind velocity measured during field operation allowed us to determine the rotor's power coefficient C p , which had a maximum value of 35%. For the stored energy components measured data indicated that the rectifier, the battery bank, and the inverter operated with average efficiencies of 95%, 78% and 86% respectively. The combined component efficiencies showed a maximum of 17% of the wind energy would be available for water pumping. Since a large amount of wind energy was dissipated during the energy conversion process, new configurations should be analyzed that could avoid such losses in wind pumping systems.

Efficiency assessment of a wind pumping system

Energy Technology Data Exchange (ETDEWEB)

Lara, David D.; Merino, Gabriel G. [Department of Mechanization and Energy, University of Concepcion, Avenida Vicente Mendez 595, Chillan (Chile); Pavez, Boris J. [Department of Electrical Engineering, University of La Frontera, Casilla 54-D, Temuco (Chile); Tapia, Juan A. [Department of Electrical Engineering, University of Concepcion, Casilla 160-C, Concepcion (Chile)

2011-02-15

The combined efficiency of the components determines overall system performance in electric wind pumping systems. We evaluated a system composed of a 3 kW wind generator feeding a battery bank of 48 V/880 Ah by means of a non-controlled 6-pulse rectifier. Connected to this battery bank was a 1.5 kW inverter that generated 220 V at 50 Hz, which powers a 1.1 kW single-phase electric pump. At the University of Concepcion, Chile, energy losses in each electrical component was determined using a data collection system configured to measure electrical variables in real time. The electrical power generated by the wind generator for different wind speeds averaged 38% lower than the power curve provided by the manufacturer. Electromechanical tests performed in a lab showed the operation efficiency of the electric generator of the wind turbine averaged 80%. This information, along with the electrical power output, and the wind velocity measured during field operation allowed us to determine the rotor's power coefficient C{sub p}, which had a maximum value of 35%. For the stored energy components measured data indicated that the rectifier, the battery bank, and the inverter operated with average efficiencies of 95%, 78% and 86% respectively. The combined component efficiencies showed a maximum of 17% of the wind energy would be available for water pumping. Since a large amount of wind energy was dissipated during the energy conversion process, new configurations should be analyzed that could avoid such losses in wind pumping systems. (author)

Modification of the algorithm for steam turbine control under loading drop

International Nuclear Information System (INIS)

Nikitin, Yu.V.; Mirnyj, V.A.; Gritsenko, V.N.; Nesterov, L.V.

1989-01-01

Problem related to powerful steam turbine control in case of emergency loading drop is considered. Two laws of control creating conditions for qualitative operation of control system under conditions considered are compared. The system of turbine control comprises the turbine major actuating mechanisms (electrohydraulic transducer, high-pressure servomotor, cut-off slide valve) actuating mechanisms of pulse discharge channel (low-pressure servomotor cut-off slide valve, low-pressure servomotor) and regulator. The frequency of the turbine rotor rotation is the parameter to be controlled in the mode of loading drop. The algorithms considered are based on linear variant of the optimal control theory. One of them is realized in electrohydraulic system of the K-750-65/3000 turbine control at the Ignalinsk NPP

Problems in creation of modern air inlet filters of power gas turbine plants in Russia and methods of their solving

Science.gov (United States)

Mikhaylov, V. E.; Khomenok, L. A.; Sherapov, V. V.

2016-08-01

The main problems in creation and operation of modern air inlet paths of gas turbine plants installed as part of combined-cycle plants in Russia are presented. It is noted that design features of air inlet filters shall be formed at the stage of the technical assignment not only considering the requirements of gas turbine plant manufacturer but also climatic conditions, local atmospheric air dustiness, and a number of other factors. The recommendations on completing of filtration system for air inlet filter of power gas turbine plants depending on the facility location are given, specific defects in design and experience in operation of imported air inlet paths are analyzed, and influence of cycle air preparation quality for gas turbine plant on value of operating expenses and cost of repair works is noted. Air treatment equipment of various manufacturers, influence of aerodynamic characteristics on operation of air inlet filters, features of filtration system operation, anti-icing system, weather canopies, and other elements of air inlet paths are considered. It is shown that nonuniformity of air flow velocity fields in clean air chamber has a negative effect on capacity and aerodynamic resistance of air inlet filter. Besides, the necessity in installation of a sufficient number of differential pressure transmitters allowing controlling state of each treatment stage not being limited to one measurement of total differential pressure in the filtration system is noted in the article. According to the results of the analysis trends and methods for modernization of available equipment for air inlet path, the importance of creation and implementation of new technologies for manufacturing of filtering elements on sites of Russia within the limits of import substitution are given, and measures on reliability improvement and energy efficiency for air inlet filter are considered.

Hydraulic turbines

International Nuclear Information System (INIS)

Meluk O, G.

1998-01-01

The hydraulic turbines are defined according to the specific speed, in impulse turbines and in reaction turbines. Currently, the Pelton turbines (of impulse) and the Francis and Kaplan turbines (of reaction), they are the most important machines in the hydroelectric generation. The hydraulic turbines are capable of generating in short times, large powers, from its loads zero until the total load and reject the load instantly without producing damages in the operation. When the hydraulic resources are important, the hydraulic turbines are converted in the axle of the electric system. Its combination with thermoelectric generation systems, it allow the continuing supply of the variations in demand of energy system. The available hydraulic resource in Colombia is of 93085 MW, of which solely 9% is exploited, become 79% of all the electrical country generation, 21% remaining is provided by means of the thermoelectric generation

Pumps and pump facilities. 2. ed.

International Nuclear Information System (INIS)

Bohl, W.; Bauerfeind, H.; Gutmann, G.; Leuschner, G.; Matthias, H.B.; Mengele, R.; Neumaier, R.; Vetter, G.; Wagner, W.

1981-01-01

This book deals with the common fundamental aspects of liquid pumps and gives an exemplary choice of the most important kinds of pumps. The scientific matter is dealt with by means of practical mathematical examples among other ways of presenting the matter. Survey of contents: Division on main operational data of pumps - pipe characteristics - pump characteristics - suction behaviour of the pumps - projecting and operation of rotary pumps - boiler feed pumps - reactor feed pumps - oscillating positive-displacement pumps - eccentric spiral pumps. (orig./GL) [de

Conceptual framework for sewer pump problems allowing for fuzzy ...

African Journals Online (AJOL)

2015-04-03

, however, when the platypus is considered in the set of mammals (this ..... would trigger a standby mobile pump unit to be employed in a relatively short period of time. However if a blockage were to occur at the SHD at the ...

Damping Wind and Wave Loads on a Floating Wind Turbine

DEFF Research Database (Denmark)

Christiansen, Søren; Bak, Thomas; Knudsen, Torben

2013-01-01

Offshore wind energy capitalizes on the higher and less turbulent wind speeds at sea. To enable deployment of wind turbines in deep-water locations, structures are being explored, where wind turbines are placed on a floating platform. This combined structure presents a new control problem, due......, and we show the influence that both wind speed, wave frequencies and misalignment between wind and waves have on the system dynamics. A new control model is derived that extends standard turbine models to include the hydrodynamics, additional platform degrees of freedom, the platform mooring system...

Feasibility Study of a Simulation Driven Approach for Estimating Reliability of Wind Turbine Fluid Power Pitch Systems

DEFF Research Database (Denmark)

Liniger, Jesper; Pedersen, Henrik Clemmensen; N. Soltani, Mohsen

2018-01-01

Recent field data indicates that pitch systems account for a substantial part of a wind turbines down time. Reducing downtime means increasing the total amount of energy produced during its lifetime. Both electrical and fluid power pitch systems are employed with a roughly 50/50 distribution. Fluid...... power pitch systems generally show higher reliability and have been favored on larger offshore wind turbines. Still general issues such as leakage, contamination and electrical faults make current systems work sub-optimal. Current field data for wind turbines present overall pitch system reliability...... and the reliability of component groups (valves, accumulators, pumps etc.). However, the failure modes of the components and more importantly the root causes are not evident. The root causes and failure mode probabilities are central for changing current pitch system designs and operational concepts to increase...

Water Hammer in Pumped Sewer Mains

DEFF Research Database (Denmark)

Larsen, Torben

of transients in pumped pipeline systems. This present publication can be understood as the second and revised edition of the pamphlet ”Transients in pumped sewer mains” (2006) which was published as a technical report by The EVA committee under The Danish Water Pollution Committee (The Danish Society......This publication is intended for students and engineers seeking an introduction to the problem of water transients in pumped sewer and water mains. This is a subject of increasing interest because of the development of larger and more integrated systems. Consideration of transients is essential...

Study on the glaze ice accretion of wind turbine with various chord lengths

Science.gov (United States)

Liang, Jian; Liu, Maolian; Wang, Ruiqi; Wang, Yuhang

2018-02-01

Wind turbine icing often occurs in winter, which changes the aerodynamic characteristics of the blades and reduces the work efficiency of the wind turbine. In this paper, the glaze ice model is established for horizontal-axis wind turbine in 3-D. The model contains the grid generation, two-phase simulation, heat and mass transfer. Results show that smaller wind turbine suffers from more serious icing problem, which reflects on a larger ice thickness. Both the collision efficiency and heat transfer coefficient increase under smaller size condition.

Steam Turbine Control Valve Stiction Effect on Power System Stability

International Nuclear Information System (INIS)

Halimi, B.

2010-01-01

One of the most important problems in power system dynamic stability is low frequency oscillations. This kind of oscillation has significant effects on the stability and security of the power system. In some previous papers, a fact was introduced that a steam pressure continuous fluctuation in turbine steam inlet pipeline may lead to a kind of low frequency oscillation of power systems. Generally, in a power generation plant, steam turbine system composes of some main components, i.e. a boiler or steam generator, stop valves, control valves and turbines that are connected by piping. In the conventional system, the turbine system is composed with a lot of stop and control valves. The steam is provided by a boiler or steam generator. In an abnormal case, the stop valve shuts of the steal flow to the turbine. The steam flow to the turbine is regulated by controlling the control valves. The control valves are provided to regulate the flow of steam to the turbine for starting, increasing or decreasing the power, and also maintaining speed control with the turbine governor system. Unfortunately, the control valve has inherent static friction (stiction) nonlinearity characteristics. Industrial surveys indicated that about 20-30% of all control loops oscillate due to valve problem caused by this nonlinear characteristic. In this paper, steam turbine control valve stiction effect on power system oscillation is presented. To analyze the stiction characteristic effect, firstly a model of control valve and its stiction characteristic are derived by using Newton's laws. A complete tandem steam prime mover, including a speed governing system, a four-stage steam turbine, and a shaft with up to for masses is adopted to analyze the performance of the steam turbine. The governor system consists of some important parts, i.e. a proportional controller, speed relay, control valve with its stiction characteristic, and stem lift position of control valve controller. The steam turbine has

Some Problems of the Integration of Heat Pump Technology into a System of Combined Heat and Electricity Production

Directory of Open Access Journals (Sweden)

G. Böszörményi

2001-01-01

Full Text Available The closure of a part of the municipal combined heat and power (CHP plant of Košice city would result in the loss of 200 MW thermal output within a realtively short period of time. The long term development plan for the Košice district heating system concentrates on solving this problem. Taking into account the extremely high (90 % dependence of Slovakia on imported energy sources and the desirability of reducing the emission of pollutantst the alternative of supplying of 100 MW thermal output from geothermal sources is attractive. However the indices of economic efficiency for this alternative are unsatisfactory. Cogeneration of electricity and heat in a CHP plant, the most efficient way of supplying heat to Košice at the present time. If as planned, geothermal heat is fed directly into the district heating network the efficiency would be greatly reduced. An excellent solution of this problem would be a new conception, preferring the utilization of geothermal heat in support of a combined electricity and heat production process. The efficiency of geothermal energy utilization could be increased through a special heat pump. This paper deals with several aspects of the design of a heat pump to be integrated into the system of the CHP plant.

Turbine main engines

CERN Document Server

Main, John B; Herbert, C W; Bennett, A J S

1965-01-01

Turbine Main Engines deals with the principle of operation of turbine main engines. Topics covered include practical considerations that affect turbine design and efficiency; steam turbine rotors, blades, nozzles, and diaphragms; lubricating oil systems; and gas turbines for use with nuclear reactors. Gas turbines for naval boost propulsion, merchant ship propulsion, and naval main propulsion are also considered. This book is divided into three parts and begins with an overview of the basic mode of operation of the steam turbine engine and how it converts the pressure energy of the ingoing ste

Hydraulic and structural co-simulation analysis of turbine runner during operation

International Nuclear Information System (INIS)

Markov, Zoran; Popovski, Predrag; Lipej, Andrej; Djelic, Vesko

2006-01-01

Modern concept of HPP refurbishment procedure consists of many aspects of the turbine re-design. One of the most useful data is the previous operational data during the lifetime of the unit. In many cases, high stressed areas are damaged. Lack of the measurements makes the solution of the problems and verification of the numerical results very difficult. This work represents an integrated approach in solving hydraulic and structural problems in design stage or optimization of an aial hydro turbine. CFD approach is implemented in solving the flow through a complete aial turbine, taking into account all the necessary factors influencing the real flow. Frozen rotor condition is taken as an input in the computations. The results from the CFD calculations are used as an input for the performed FEA modeling and structural analysis.

An innovative and very promising use of tidal turbines. Tidal turbines can produce twenty per cent of the French electricity. An economic solution can produce 500 GW of tide energy. An innovative use of tidal turbines can produce 10 per cent of the World energy

International Nuclear Information System (INIS)

Lemperiere, F.

2013-01-01

A set of articles outlines and describes the opportunities of energy production associated with the use of tidal turbines. Such a technological principle is very efficient in terms of costs but very few natural sea or river sites present favourable conditions, notably in terms of current speed. A first article addresses the peculiarities of sea tide energy, presents the different concepts and components of a sea tide power plant (tanks or basins, plants), describes the present use of tidal turbines, proposes a new solution (the 'Marelienne'), describes and assesses the integration into the grid and the energy storage, evokes the production gain obtained by pumping and the association with wind turbines, describes the construction mode, discusses the various impacts (visual impact, impacts on the environment, direct and indirect socio-economic impacts), discusses issues related to navigation, presents an example of production, costs and impacts (case of the Bay of Somme), evokes other potential areas in France (about the Chausey island and about the Re island), discusses the world potential, evokes other examples in Europe, in Asia, in America, Africa and Australia), indicates the global cost for the main sites, outlines technical and economic uncertainties. The same aspects and issues can be found in the other articles which outline that tidal turbines can produce twenty per cent of the French electricity, that an economic solution can produce 500 GW of tide energy, and that an innovative use of tidal turbines can produce 10 per cent of the World energy

Energy saving in agricultural pumping equipment; Ahorro de energia en equipos de bombeo agricola

Energy Technology Data Exchange (ETDEWEB)

Acosta Torres, R Aracely [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1994-12-31

This paper analyses the current state of the pumping equipment for agricultural irrigation in Mexico. Because of being of the vertical centrifugal turbine type pumps, the most commonly utilized for this service, the study has been focussed into this equipment, obtaining efficiency and consumption scenarios, as well as the potential energy saving existing in this sector. [Espanol] En el presente articulo se analiza el estado actual de los equipos de bombeo para riego agricola en Mexico, al ser las bombas centrifugas verticales tipo turbina, las mas comunmente utilizadas para este servicio, el estudio ha sido enfocado a estos equipos, obteniendose los escenarios de eficiencias y consumos, asi como, el potencial de ahorro energetico existente en este sector.

Energy saving in agricultural pumping equipment; Ahorro de energia en equipos de bombeo agricola

Energy Technology Data Exchange (ETDEWEB)

Acosta Torres, R. Aracely [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1993-12-31

This paper analyses the current state of the pumping equipment for agricultural irrigation in Mexico. Because of being of the vertical centrifugal turbine type pumps, the most commonly utilized for this service, the study has been focussed into this equipment, obtaining efficiency and consumption scenarios, as well as the potential energy saving existing in this sector. [Espanol] En el presente articulo se analiza el estado actual de los equipos de bombeo para riego agricola en Mexico, al ser las bombas centrifugas verticales tipo turbina, las mas comunmente utilizadas para este servicio, el estudio ha sido enfocado a estos equipos, obteniendose los escenarios de eficiencias y consumos, asi como, el potencial de ahorro energetico existente en este sector.

The cool seal system: a practical solution to the shaft seal problem and heat related complications with implantable rotary blood pumps.

Science.gov (United States)

Yamazaki, K; Mori, T; Tomioka, J; Litwak, P; Antaki, J F; Tagusari, O; Koyanagi, H; Griffith, B P; Kormos, R L

1997-01-01

A critical issue facing the development of an implantable, rotary blood pump is the maintenance of an effective seal at the rotating shaft. Mechanical seals are the most versatile type of seal in wide industrial applications. However, in a rotary blood pump, typical seal life is much shorter than required for chronic support. Seal failure is related to adhesion and aggregation of heat denatured blood proteins that diffuse into the lubricating film between seal faces. Among the blood proteins, fibrinogen plays an important role due to its strong propensity for adhesion and low transition temperature (approximately 50 degrees C). Once exposed to temperature exceeding 50 degrees C, fibrinogen molecules fuse together by multi-attachment between heat denatured D-domains. This quasi-polymerized fibrin increases the frictional heat, which proliferates the process into seal failure. If the temperature of the seal faces is maintained well below 50 degrees C, a mechanical seal would not fail in blood. Based on this "Cool-Seal" concept, we developed a miniature mechanical seal made of highly thermally conductive material (SiC), combined with a recirculating purge system. A large supply of purge fluid is recirculated behind the seal face to augment convective heat transfer to maintain the seal temperature below 40 degrees C. It also cools all heat generating pump parts (motor coil, bearing, seal). The purge consumption has been optimized to virtually nil (seal system has now been incorporated into our intraventricular axial flow blood pump (IVAP) and newly designed centrifugal pump. Ongoing in vivo evaluation of these systems has demonstrated good seal integrity for more than 160 days. The Cool-Seal system can be applied to any type of rotary blood pump (axial, diagonal, centrifugal, etc.) and offers a practical solution to the shaft seal problem and heat related complications, which currently limit the use of implantable rotary blood pumps.

Demonstrating demand response from water distribution system through pump scheduling

International Nuclear Information System (INIS)

Menke, Ruben; Abraham, Edo; Parpas, Panos; Stoianov, Ivan

2016-01-01

Highlights: • Water distribution systems can profitably provide demand response energy. • STOR and FFR are financially viable under a wide range of operating conditions. • Viability depends on the pump utilisation and peak price of the electricity tariff. • Total GHG emissions caused by the provision of reserve energy are <300 gCO_2/kW h. • These are lower than those from the major reserve energy provision technologies. - Abstract: Significant changes in the power generation mix are posing new challenges for the balancing systems of the grid. Many of these challenges are in the secondary electricity grid regulation services and could be met through demand response (DR) services. We explore the opportunities for a water distribution system (WDS) to provide balancing services with demand response through pump scheduling and evaluate the associated benefits. Using a benchmark network and demand response mechanisms available in the UK, these benefits are assessed in terms of reduced green house gas (GHG) emissions from the grid due to the displacement of more polluting power sources and additional revenues for water utilities. The optimal pump scheduling problem is formulated as a mixed-integer optimisation problem and solved using a branch and bound algorithm. This new formulation finds the optimal level of power capacity to commit to the provision of demand response for a range of reserve energy provision and frequency response schemes offered in the UK. For the first time we show that DR from WDS can offer financial benefits to WDS operators while providing response energy to the grid with less greenhouse gas emissions than competing reserve energy technologies. Using a Monte Carlo simulation based on data from 2014, we demonstrate that the cost of providing the storage energy is less than the financial compensation available for the equivalent energy supply. The GHG emissions from the demand response provision from a WDS are also shown to be smaller than

Balancing Energy Processes in Turbine Engines

Directory of Open Access Journals (Sweden)

Balicki Włodzimierz

2015-01-01

Full Text Available The article discusses the issue of balancing energy processes in turbine engines in operation in aeronautic and marine propulsion systems with the aim to analyse and evaluate basic operating parameters. The first part presents the problem of enormous amounts of energy needed for driving fans and compressors of the largest contemporary turbofan engines commonly used in long-distance aviation. The amounts of the transmitted power and the effect of flow parameters and constructional properties of the engines on their performance and real efficiency are evaluated. The second part of the article, devoted to marine applications of turbine engines, presents the energy balance of the kinetic system of torque transmission from main engine turbines to screw propellers in the combined system of COGAG type. The physical model of energy conversion processes executed in this system is presented, along with the physical model of gasodynamic processes taking place in a separate driving turbine of a reversing engine. These models have made the basis for formulating balance equations, which then were used for analysing static and dynamic properties of the analysed type of propulsion, in particular in the aspect of mechanical loss evaluation in its kinematic system.

Power control for wind turbines in weak grids: Concepts development

DEFF Research Database (Denmark)

Bindner, H.

1999-01-01

will make wind power more firm and possible to connect to weaker grids. So, when the concept is matured, theexpectation is that for certain wind power installations, the cost of the power control is paid back as added wind power capacity value and saved grid reinforcement costs. Different systems...... and analyze methods and technologies for making it viable to utilize more of the wind potential in remote areas. The suggestion is to develop a power control concept for wind turbines which will even out thepower fluctuations and make it possible to increase the wind energy penetration. The main options...... are to combine wind power with a pumped hydro power storage or with an AC/DC converter and battery storage. The AC/DC converter can either be an "add-on" typeor it can be designed as an integrated part of a variable speed wind turbine. The idea is that combining wind power with the power control concept...

Turbinate surgery

Science.gov (United States)

Turbinectomy; Turbinoplasty; Turbinate reduction; Nasal airway surgery; Nasal obstruction - turbinate surgery ... There are several types of turbinate surgery: Turbinectomy: All or ... This can be done in several different ways, but sometimes a ...

Application of Circulation Controlled Blades for Vertical Axis Wind Turbines

Directory of Open Access Journals (Sweden)

Velissarios Kourkoulis

2013-07-01

Full Text Available The blades of a vertical axis wind turbine (VAWT rotor see an inconsistent angle of attack through its rotation. Consequently, VAWT blades generally use symmetrical aerofoils with a lower lift-to-drag ratio than cambered aerofoils tailored to maximise horizontal axis wind turbine rotor performance. This paper considers the feasibility of circulation controlled (CC VAWT blades, using a tangential air jet to provide lift and therefore power augmentation. However CC blade sections require a higher trailing-edge thickness than conventional sections giving rise to additional base drag. The choice of design parameters is a compromise between lift augmentation, additional base drag as well as the power required to pump the air jet. Although CC technology has been investigated for many years, particularly for aerospace applications, few researchers have considered VAWT applications. This paper considers the feasibility of the technology, using Computational Fluid Dynamics to evaluate a baseline CC aerofoil with different trailing-edge ellipse shapes. Lift and drag increments due to CC are considered within a momentum based turbine model to determine net power production. The study found that for modest momentum coefficients significant net power augmentation can be achieved with a relatively simple aerofoil geometry if blowing is controlled through the blades rotation.

Power control for wind turbines in weak grids: Project summary

DEFF Research Database (Denmark)

Bindner, H.

1999-01-01

. The two case studies (Madeira, Portugal and Co. Donegal, Ireland) revealed that sometimes theleast cost and most attractive option is change in the operating strategy of the power system. This allowed that further wind energy can be integrated at competitive cost in the Madeira power system. In Co....... Donegal the options for pumped storage are goodcombined with good wind resources. Unfortunately the grid is weak. The least cost option for the feeder studied is either grid reinforcement or a power control system based on pumped storage if rather large amounts of wind energy are to be absorbed...... by thepower system. The cost estimates for the two options are in the same range. The current report is a summary of the work done in the project 'Power Control for Wind Turbines in Weak Grids'. The project has been partly funded by EU under contractJOR3-CT95-0067....

Turbine repair process, repaired coating, and repaired turbine component

Science.gov (United States)

Das, Rupak; Delvaux, John McConnell; Garcia-Crespo, Andres Jose

2015-11-03

A turbine repair process, a repaired coating, and a repaired turbine component are disclosed. The turbine repair process includes providing a turbine component having a higher-pressure region and a lower-pressure region, introducing particles into the higher-pressure region, and at least partially repairing an opening between the higher-pressure region and the lower-pressure region with at least one of the particles to form a repaired turbine component. The repaired coating includes a silicon material, a ceramic matrix composite material, and a repaired region having the silicon material deposited on and surrounded by the ceramic matrix composite material. The repaired turbine component a ceramic matrix composite layer and a repaired region having silicon material deposited on and surrounded by the ceramic matrix composite material.

75 FR 21641 - Infusion Pumps; Public Meeting; Request for Comments

Science.gov (United States)

2010-04-26

...] Infusion Pumps; Public Meeting; Request for Comments AGENCY: Food and Drug Administration, HHS. ACTION... announcing a public meeting regarding external infusion pumps. The purpose of the meeting is to inform the public about current problems associated with external infusion pump use, to help the agency identify...

Analysis of wind energy potential for agriculture pump in mountain area Aceh Besar

Science.gov (United States)

Syuhada, Ahmad; Maulana, Muhammad Ilham; Fuadi, Zahrul

2017-06-01

In this study, the potential of wind power for agricultural pump driver in Saree mountainous area of Aceh Besar is analyzed. It is found that the average usable wind speed is 6.41 m/s, which is potential to produce 893.96 Watt of electricity with the wind turbine rotor diameter of 3 m. This energy can be used to drive up to 614 Watt of water pump with static head of 20 m to irrigate 19 hectare of land, 7 hours a day. HOMER analysis indicated the lowest simulated NPC value of USD 10.028 with CoE of USD 0.717 kWh. It is also indicated that the wind has potential to produce 3452 kWh/year with lifetime of 15 years.

Selection of References in Wind Turbine Model Predictive Control Design

DEFF Research Database (Denmark)

Odgaard, Peter Fogh; Hovgaard, Tobias

2015-01-01

a model predictive controller for a wind turbine. One of the important aspects for a tracking control problem is how to setup the optimal reference tracking problem, as it might be relevant to track, e.g., the three concurrent references: optimal pitch angle, optimal rotational speed, and optimal power......Lowering the cost of energy is one of the major focus areas in the wind turbine industry. Recent research has indicated that wind turbine controllers based on model predictive control methods can be useful in obtaining this objective. A number of design considerations have to be made when designing....... The importance if the individual references differ depending in particular on the wind speed. In this paper we investigate the performance of a reference tracking model predictive controller with two different setups of the used optimal reference signals. The controllers are evaluated using an industrial high...

A review of damage detection methods for wind turbine blades

International Nuclear Information System (INIS)

Li, Dongsheng; Song, Gangbing; Ren, Liang; Li, Hongnan; Ho, Siu-Chun M

2015-01-01

Wind energy is one of the most important renewable energy sources and many countries are predicted to increase wind energy portion of their whole national energy supply to about twenty percent in the next decade. One potential obstacle in the use of wind turbines to harvest wind energy is the maintenance of the wind turbine blades. The blades are a crucial and costly part of a wind turbine and over their service life can suffer from factors such as material degradation and fatigue, which can limit their effectiveness and safety. Thus, the ability to detect damage in wind turbine blades is of great significance for planning maintenance and continued operation of the wind turbine. This paper presents a review of recent research and development in the field of damage detection for wind turbine blades. Specifically, this paper reviews frequently employed sensors including fiber optic and piezoelectric sensors, and four promising damage detection methods, namely, transmittance function, wave propagation, impedance and vibration based methods. As a note towards the future development trend for wind turbine sensing systems, the necessity for wireless sensing and energy harvesting is briefly presented. Finally, existing problems and promising research efforts for online damage detection of turbine blades are discussed. (topical review)

Adaptive neuro-fuzzy methodology for noise assessment of wind turbine.

Science.gov (United States)

Shamshirband, Shahaboddin; Petković, Dalibor; Hashim, Roslan; Motamedi, Shervin

2014-01-01

Wind turbine noise is one of the major obstacles for the widespread use of wind energy. Noise tone can greatly increase the annoyance factor and the negative impact on human health. Noise annoyance caused by wind turbines has become an emerging problem in recent years, due to the rapid increase in number of wind turbines, triggered by sustainable energy goals set forward at the national and international level. Up to now, not all aspects of the generation, propagation and perception of wind turbine noise are well understood. For a modern large wind turbine, aerodynamic noise from the blades is generally considered to be the dominant noise source, provided that mechanical noise is adequately eliminated. The sources of aerodynamic noise can be divided into tonal noise, inflow turbulence noise, and airfoil self-noise. Many analytical and experimental acoustical studies performed the wind turbines. Since the wind turbine noise level analyzing by numerical methods or computational fluid dynamics (CFD) could be very challenging and time consuming, soft computing techniques are preferred. To estimate noise level of wind turbine, this paper constructed a process which simulates the wind turbine noise levels in regard to wind speed and sound frequency with adaptive neuro-fuzzy inference system (ANFIS). This intelligent estimator is implemented using Matlab/Simulink and the performances are investigated. The simulation results presented in this paper show the effectiveness of the developed method.

System Identification of Wind Turbines for Structural Health Monitoring

DEFF Research Database (Denmark)

Perisic, Nevena

Structural health monitoring is a multi-disciplinary engineering field that should allow the actual wind turbine maintenance programmes to evolve to the next level, hence increasing safety and reliability and decreasing turbines downtime. The main idea is to have a sensing system on the structure...... cases are considered, two practical problems from the wind industry are studied, i.e. monitoring of the gearbox shaft torque and the tower root bending moments. The second part of the thesis is focused on the influence of friction on the health of the wind turbine and on the nonlinear identification...... that monitors the system responses and notifies the operator when damages or degradations have been detected. However, some of the response signals that contain important information about the health of the wind turbine components cannot be directly measured, or measuring them is highly complex and costly...

Assessment and prediction of wind turbine noise

International Nuclear Information System (INIS)

Lowson, M.V.

1993-01-01

The significance of basic aerodynamic noise sources for wind turbine noise are assessed, using information on the aero-acoustic mechanisms of other rotors, which have been studied in depth for many years. From the analysis, areas of potential improvement in wind turbine noise prediction are defined. Suggestions are made for approaches to wind turbine noise control which separate the noise problems at cut-in from those at rated power. Some of these offer the possibility of noise reduction without unfavourable effects on performance. Based on this analysis, a new model for prediction of wind turbine noise is presented and comparisons made between prediction and experiment. The model is based on well established aeroacoustic theory and published laboratory data for the two principal sources, inflow turbulence and boundary layer trailing edge interaction. The new method gives good agreement with experiment with the case studied so far. Parametric trends and sensitivities for the model are presented. Comparisons with previous prediction methods are also given. A consequence of the new model is to put more emphasis on boundary layer trailing edge interaction as a noise source. There are prospects for reducing noise from this source detail changes to the wind turbine design. (author)

Considerations for reference pump curves

International Nuclear Information System (INIS)

Stockton, N.B.

1992-01-01

This paper examines problems associated with inservice testing (IST) of pumps to assess their hydraulic performance using reference pump curves to establish acceptance criteria. Safety-related pumps at nuclear power plants are tested under the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (the Code), Section 11. The Code requires testing pumps at specific reference points of differential pressure or flow rate that can be readily duplicated during subsequent tests. There are many cases where test conditions cannot be duplicated. For some pumps, such as service water or component cooling pumps, the flow rate at any time depends on plant conditions and the arrangement of multiple independent and constantly changing loads. System conditions cannot be controlled to duplicate a specific reference value. In these cases, utilities frequently request to use pump curves for comparison of test data for acceptance. There is no prescribed method for developing a pump reference curve. The methods vary and may yield substantially different results. Some results are conservative when compared to the Code requirements; some are not. The errors associated with different curve testing techniques should be understood and controlled within reasonable bounds. Manufacturer's pump curves, in general, are not sufficiently accurate to use as reference pump curves for IST. Testing using reference curves generated with polynomial least squares fits over limited ranges of pump operation, cubic spline interpolation, or cubic spline least squares fits can provide a measure of pump hydraulic performance that is at least as accurate as the Code required method. Regardless of the test method, error can be reduced by using more accurate instruments, by correcting for systematic errors, by increasing the number of data points, and by taking repetitive measurements at each data point

Mechanical pumps for liquid metals; Pompes mecaniques pour metaux liquides

Energy Technology Data Exchange (ETDEWEB)

Baumier, J; Gollion, H J [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1964-07-01

The pumping of liquid metals by centrifugal pumps poses two principal problems. These are hermetic sealing of the rotating shaft and, its guidance where immersed in liquid metal. The solutions to the problems used on 13 experimental pumps are given here. The resolution of the guidance problem consists in the majority of cases in the utilisation of hydrostatic bearings. Accordingly, a theoretical study was instituted for the first time to calculate the bearings of the earlier pumps. After this, an experimental study was carried out, to check the theory by water tests. A relation for bearing calculation of pumps with diffusers is proposed. Finally the influence of the bearing elasticity on the shafts critical speed is studied. (authors) [French] Le pompage des metaux liquides, par des pompes centrifuges, pose 2 principaux problemes, qui sont: d'une part, la realisation d'une excellente etancheite au passage de l'arbre, d'autre part, son guidage sur la partie immergee dans le metal liquide. Les solutions retenues pour resoudre ces problemes sur 13 pompes experimentees sont presentees. Le probleme du guidage de l'arbre, a dans la majorite des cas ete resolu en utilisant un palier hydrostatique, aussi l'etude en a d'abord ete approfondie de facon theorique pour calculer les paliers des premieres pompes, puis experimentale pour controler la theorie, en effectuant des essais a l'eau. On propose une relation pour calculer les paliers des pompes a diffuseurs. On a en outre effectue une etude de l'influence de l'elasticite du palier hydrostatique sur la vitesse critique de l'arbre. (auteurs)

Operating problem of low specific speed pumps operating in closed hydraulic loop

International Nuclear Information System (INIS)

Rajput, A.K.

1979-01-01

Results of the studies of pressure pulsations caused by the centrifugal pump driving a typical sodium test loop are presented. The method of characteristics has been used for solving the equations of unsteady fluid flow in closed hydraulic loops with various boundary points, important of which are pump, control valve and heater tank (acting hydraulically as surge tank). Mathematical and computational models used for calculations are described. (M.G.B.)

Development and Optimized Design of Propeller Pump System & Structure with VFD in Low-head Pumping Station

Science.gov (United States)

Rentian, Zhang; Honggeng, Zhu; Arnold, Jaap; Linbi, Yao

2010-06-01

Compared with vertical-installed pumps, the propeller (bulb tubular) pump systems can achieve higher hydraulic efficiencies, which are particularly suitable for low-head pumping stations. More than four propeller pumping stations are being, or will be built in the first stage of the S-to-N Water Diversion Project in China, diverting water from Yangtze River to the northern part of China to alleviate water-shortage problems and develop the economy. New structures of propeller pump have been developed for specified pumping stations in Jiangsu and Shandong Provinces respectively and Variable Frequency Drives (VFDs) are used in those pumping stations to regulate operating conditions. Based on the Navier-Stokes equations and the standard k-e turbulent model, numerical simulations of the flow field and performance prediction in the propeller pump system were conducted on the platform of commercial software CFX by using the SIMPLEC algorithm. Through optimal design of bulb dimensions and diffuser channel shape, the hydraulic system efficiency has improved evidently. Furthermore, the structures of propeller pumps have been optimized to for the introduction of conventional as well as permanent magnet motors. In order to improve the hydraulic efficiency of pumping systems, both the pump discharge and the motor diameter were optimized respectively. If a conventional motor is used, the diameter of the pump casing has to be increased to accommodate the motor installed inside. If using a permanent magnet motor, the diameter of motor casing can be decreased effectively without decreasing its output power, thus the cross-sectional area is enlarged and the velocity of flowing water decreased favorably to reduce hydraulic loss of discharge channel and thereby raising the pumping system efficiency. Witness model tests were conducted after numerical optimization on specific propeller pump systems, indicating that the model system hydraulic efficiencies can be improved by 0.5%˜3.7% in

Energy storage by compressed air. [using windpowered pumps

Science.gov (United States)

Szego, G. C.

1973-01-01

The feasibility of windpower energy storage by compressed air is considered. The system is comprised of a compressor, a motor, and a pump turbine to store air in caverns or aquifiers. It is proposed that storage of several days worth of compressed air up to 650 pounds per square inch can be used to push the aquifier up closer to the container dome and thus initiate piston action by simply compressing air more and more. More energy can be put into it by pressure increase or pushing back the water in the aquifier. This storage system concept has reheat flexibility and lowest cost effectiveness.

Aerodynamic flow simulation of wind turbine: Downwind versus upwind configuration

International Nuclear Information System (INIS)

Janajreh, Isam; Qudaih, Rana; Talab, Ilham; Ghenai, Chaouki

2010-01-01

Large scale wind turbines and wind farms continue to grow mounting 94.1 GW of the electrical grid capacity in 2007 and expected to reach 160.0 GW in 2010. Wind energy plays a vital role in the quest for renewable and sustainable energy as well as in reducing carbon emission. Early generation wind turbines (windmills) were used mainly for water pumping and seed grinding, whereas today they generate 1/5 of the current Denmark's electricity and will double its grid capacity reaching 12.5% in 2010. Wind energy is plentiful (72 TW estimated to be commercially viable) and clean while its intensive capital cost still impede widespread deployment. However, there are technological challenges, i.e. high fatigue load, noise emission, and meeting stringent reliability and safety standards. Newer inventions, e.g., downstream wind turbines and flapping rotor blades, are sought to enhance their performance, i.e. lower turning moments and cut-in speed and to absorb portion of the cost due to the absent of yaw mechanisms. In this work, numerical analysis of the downstream wind turbine blade is conducted. In particular, the interaction between the tower and the rotor passage is investigated. Circular cross sectional tower and aerofoil shapes are considered in a staggered configuration and under cross-stream motion. The resulting blade static pressure and aerodynamic forces are computed at different incident wind angles and wind speeds. The computed forces are compared to the conventional upstream wind turbine. Steady state and transient, incompressible, viscous Navier-Stokes and turbulent flow analysis are employed. The k-epsilon model is utilized as the turbulence closure. The passage of the rotor blade is governed by ALE and is represented numerically as a sliding mesh against the upstream fixed tower domain.

Alizes: Wind pumping project in Mauritania

International Nuclear Information System (INIS)

Monvois, J.; Reboulet, M.

1991-01-01

GRET started the title project in May 1990. About 50,000 people live in the area around Rosso, Mauritania, where the project is located. An essential aspect of the project is that villagers themselves need to ask for a wind pump. Moreover, the wind pumps are locally manufactured by a small enterprise. The counterparts are the Mauritanian Ministry of Energy, and the non-gouvernmental Institute Dello and Espace Eolien Regional in France. The Oasis multibladed windmill (2,5 diameter) was chosen, because it is easy to manufacture, it is easy to maintain and quite cheap. To avoid problems it is decided not to pump water from a depth more than 20 meters. The total costs of a wind pump amount to approximately US$ 8,000. for obtaining a wind pump, the villagers need to pay 15% of this total amount. 5 figs., 1 tab

Modal Analysis on Fluid-Structure Interaction of MW-Level Vertical Axis Wind Turbine Tower

OpenAIRE

Tan Jiqiu; Zhong Dingqing; Wang Qiong

2014-01-01

In order to avoid resonance problem of MW-level vertical axis wind turbine induced by wind, a flow field model of the MW-level vertical axis wind turbine is established by using the fluid flow control equations, calculate flow’s velocity and pressure of the MW-level vertical axis wind turbine and load onto tower’s before and after surface, study the Modal analysis of fluid-structure interaction of MW-level vertical axis wind turbine tower. The results show that fluid-structure interaction fie...

Energetic and exergetic analysis of a steam turbine power plant in an existing phosphoric acid factory

International Nuclear Information System (INIS)

Hafdhi, Fathia; Khir, Tahar; Ben Yahyia, Ali; Ben Brahim, Ammar

2015-01-01

Highlights: • The operating mode of the factory and the power supply streams are presented. • Energetic Analysis of steam turbine power plant of an existing phosphoric acid factory. • Exergetic Analysis of each component of steam turbine power plant and the different heat recovery system. • Energy, exergy efficiency and irreversibility rates for the main components are determined. • The effect of the operating parameters on the plant performance are analyzed. - Abstract: An energetic and exergetic analysis is conducted on a Steam Turbine Power Plant of an existing Phosphoric Acid Factory. The heat recovery systems used in the different parts of the plant are also considered in the study. Mass, energy and exergy balances are established on the main compounds of the plant. A numerical code is established using EES software to perform the calculations required for the thermal and exergy plant analysis considering real variation ranges of the main operating parameters such as pressure, temperature and mass flow rate. The effects of theses parameters on the system performances are investigated. The main sources of irreversibility are the melters, followed by the heat exchangers, the steam turbine generator and the pumps. The maximum energy efficiency is obtained for the blower followed by the heat exchangers, the deaerator and the steam turbine generator. The exergy efficiency obtained for the heat exchanger, the steam turbine generator, the deaerator and the blower are 88%, 74%, 72% and 66% respectively. The effects of High Pressure steam temperature and pressure on the steam turbine generator energy and exergy efficiencies are investigated.

Controlling Voltage Levels of Distribution Network-Radial Feeder after Connecting Wind Turbines to the Network

Directory of Open Access Journals (Sweden)

Muhammad Al Badri

2017-11-01

Full Text Available Several factors in power generation and supply need to be taken into account such as shortages of energy supply, system stability, and energy quality and system disruption due to network losses, industrial development and population expansion. The addition of wind turbines to the distribution network is of great benefit in providing additional power and solving these problems, but this addition is accompanied by the problem of low voltage network. This research found optimal solutions to the problem of low voltage distribution network after connecting wind turbines. The main idea of this paper is to optimize the low-voltage problem as a result of connecting the wind turbines to the "far end" of the radial feeder for a distribution network and to obtain a voltage level within an acceptable and stable range. The problem of low voltage solved by using the load-drop compensation, capacitor-bank and “doubly-fed” induction generators. The results of this study were based on the operation of the entire design of the simulation system which would be compatible with the reality of the energy flow of all network components by using the PSCAD program. The present analysis program revealed an optimum solution for the low voltage profile of the distribution network after connecting the wind turbine.

Feasibility study of a Green Power Plant. Final report. [Offshore pumped hydro storage

Energy Technology Data Exchange (ETDEWEB)

NONE

2013-03-15

This project is a technical evaluation and a feasibility study of a concept called the Green Power Plant (GPP), developed by Seahorn Energy Aps. The Green Power Plant is an offshore pumped hydro storage facility constructed from prefabricated elements and with integrated renewable energy production. Pumped hydro storage is a known technology with a proven roundtrip energy storage efficiency of 80%. The focus of the GPP project is on simplifying and industrializing the construction of the reservoir wall, thereby achieving a cost efficient solution. The reservoir structure is dependent on the site on which the reservoir is established, thus Kriegers Flak in the Baltic Sea has been chosen as basis for the technical evaluation. As soil conditions vary, the technical evaluations have been based on a general soil profile. A water depth of 25m has been chosen as basis for the evaluation. A reservoir with a diameter of 2 km has been evaluated as baseline scenario. Feasibility of the GPP was evaluated based on the cost and income estimates. For the baseline scenario an internal rate of return of 6.6% was found for a period of 35 years. A sensitivity analysis reveals internal rates of return over 35 years varying from 4.9% to 10.9%. Especially larger reservoir diameters increase profitability of the GPP. The results from this project will be utilized in raising funds for further development of the GPP concept. Seahorn Energy Aps aims at optimizing the wind turbine integration, the steel pile wall structure and the pump-turbine integration in a future project towards construction of a demonstration facility. (LN)

Reactor coolant pump seal leakage monitoring

International Nuclear Information System (INIS)

Stevens, D.M.; Spencer, J.W.; Morris, D.J.; James, W.; Shugars, H.G.

1986-01-01

Problems with reactor coolant pump seals have historically accounted for a large percentage of unscheduled outages. Studies performed for the Electric Power Research Institute (EPRI) have shown that the replacement of coolant pump seals has been one of the leading causes of nuclear plant unavailability over the last ten years. Failures of coolant pump seals can lead to primary coolant leakage rates of 200-500 gallons per minute into the reactor building. Airborne activity and high surface contamination levels following these failures require a major cleanup effort and increases the time and personnel exposure required to refurbish the pump seals. One of the problems in assessing seal integrity is the inability to accurately measure seal leakage. Because seal leakage flow is normally very small, it cannot be sensed directly with normal flow instrumentation, but must be inferred from several other temperature and flow measurements. In operating plants the leakage rate has been quantified with a tipping-bucket gauge, a device which indicates when one quart of water has been accumulated. The tipping-bucket gauge has been used for most rainfall-intensity monitoring. The need for a more accurate and less expensive gauge has been addressed. They have developed a drop-counter precipitation sensor has been developed and optimized. The applicability of the drop-counter device to the problem of measuring seal leakage is being investigated. If a review of system specification and known drop-counter performance indicates that this method is feasible for measuring seal leak rates, a drop-counter gauge will be fabricated and tested in the laboratory. If laboratory tests are successful the gauge will be demonstrated in a pump test loop at Ontario Hydro and evaluated under simulated plant conditions. 3 references, 2 figures

Robust H(infinity) tracking control of boiler-turbine systems.

Science.gov (United States)

Wu, J; Nguang, S K; Shen, J; Liu, G; Li, Y G

2010-07-01

In this paper, the problem of designing a fuzzy H(infinity) state feedback tracking control of a boiler-turbine is solved. First, the Takagi and Sugeno fuzzy model is used to model a boiler-turbine system. Next, based on the Takagi and Sugeno fuzzy model, sufficient conditions for the existence of a fuzzy H(infinity) nonlinear state feedback tracking control are derived in terms of linear matrix inequalities. The advantage of the proposed tracking control design is that it does not involve feedback linearization technique and complicated adaptive scheme. An industrial boiler-turbine system is used to illustrate the effectiveness of the proposed design as compared with a linearized approach. 2010 ISA. Published by Elsevier Ltd. All rights reserved.

Fixed-Time Stability of the Hydraulic Turbine Governing System

Directory of Open Access Journals (Sweden)

Caoyuan Ma

2018-01-01

Full Text Available This paper studies the problem of fixed-time stability of hydraulic turbine governing system with the elastic water hammer nonlinear model. To control and improve the quality of hydraulic turbine governing system, a new fixed-time control strategy is proposed, which can stabilize the water turbine governing system within a fixed time. Compared with the finite-time control strategy where the convergence rate depends on the initial state, the settling time of the fixed-time control scheme can be adjusted to the required value regardless of the initial conditions. Finally, we numerically show that the fixed-time control is more effective than and superior to the finite-time control.

The counter pressure Pelton turbine as a solution to the energy production in drinking water systems; Die Gegendruck-Peltonturbine als Loesung fuer die Energieproduktion in Trinkwassersystemen

Energy Technology Data Exchange (ETDEWEB)

Baumann, Reto [Haeny AG - Pumpen, Turbinen und Systeme, Jona (Switzerland); Juric, Thomas [A. Abel GmbH, Pumpen und Turbinen, Wundschuh (Austria)

2010-07-01

In drinking water slumbers green electricity. Up to now classical Pelton turbines or cheaper standard pumps running in reverse (PAT) were used. Both technologies have disadvantages or limitations regarding their possible applications, therefore, the optimal implementation of the existing potentials are often not entirely possible. The new ''Counter pressure Pelton turbine'' combines the advantages of both technologies and is therefore in many cases the ''most efficient solution''. (orig.)

Modal Characteristics of Novel Wind Turbine Rotors with Hinged Structures

Science.gov (United States)

Lu, Hongya; Zeng, Pan; Lei, Liping

2018-03-01

The vibration problems of the wind turbine rotors have drawn public attention as the size of wind turbine has increased incredibly. Although various factors may cause the vibration problems, the flexibility is a big threat among them. Therefore, ensuring the high stiffness of the rotors by adopting novel techniques becomes a necessity. The study was a further investigation of several novel designs regarding the dynamic behaviour and the influencing mechanism. The modal testing experiments were conducted on a traditional blade and an isolated blade with the hinged rods mounted close to the root. The results showed that the rod increased both the modal frequency and the damping of the blade. More studies were done on the rods’ impact on the wind turbine rotor with a numerical model, where dimensionless parameters were defined to describe the configuration of the interveined and the bisymmetrical rods. Their influences on the modal frequencies of the rotor were analyzed and discussed.

Steam turbine cycle

International Nuclear Information System (INIS)

Okuzumi, Naoaki.

1994-01-01

In a steam turbine cycle, steams exhausted from the turbine are extracted, and they are connected to a steam sucking pipe of a steam injector, and a discharge pipe of the steam injector is connected to an inlet of a water turbine. High pressure discharge water is obtained from low pressure steams by utilizing a pressurizing performance of the steam injector and the water turbine is rotated by the high pressure water to generate electric power. This recover and reutilize discharged heat of the steam turbine effectively, thereby enabling to improve heat efficiency of the steam turbine cycle. (T.M.)

Thermal expansion measurement of turbine and main steam piping by using strain gages in power plants

International Nuclear Information System (INIS)

Na, Sang Soo; Chung, Jae Won; Bong, Suk Kun; Jun, Dong Ki; Kim, Yun Suk

2000-01-01

One of the domestic co-generation plants have undergone excessive vibration problems of turbine attributed to external force for years. The root cause of turbine vibration may be shaft alignment problem which sometimes is changed by thermal expansion and external force, even if turbine technicians perfectly performed it. To evaluate the alignment condition from plant start-up to full load, a strain measurement of turbine and main steam piping subjected to thermal loading is monitored by using strain gages. The strain gages are bonded on both bearing housing adjusting bolts and pipe stoppers which installed in the x-direction of left-side main steam piping near the turbine inlet in order to monitor closely the effect of turbine under thermal deformation of turbine casing and main steam piping during plant full load. Also in situ load of constant support hangers in main steam piping system is measured by strain gages and its results are used to rebalance the hanger rod load. Consequently, the experimental stress analysis by using strain gages turns out to be very useful tool to diagnose the trouble and failures of not only to stationary components but to rotating machinery in power plants

Adaptive Neuro-Fuzzy Methodology for Noise Assessment of Wind Turbine

Science.gov (United States)

Shamshirband, Shahaboddin; Petković, Dalibor; Hashim, Roslan; Motamedi, Shervin

2014-01-01

Wind turbine noise is one of the major obstacles for the widespread use of wind energy. Noise tone can greatly increase the annoyance factor and the negative impact on human health. Noise annoyance caused by wind turbines has become an emerging problem in recent years, due to the rapid increase in number of wind turbines, triggered by sustainable energy goals set forward at the national and international level. Up to now, not all aspects of the generation, propagation and perception of wind turbine noise are well understood. For a modern large wind turbine, aerodynamic noise from the blades is generally considered to be the dominant noise source, provided that mechanical noise is adequately eliminated. The sources of aerodynamic noise can be divided into tonal noise, inflow turbulence noise, and airfoil self-noise. Many analytical and experimental acoustical studies performed the wind turbines. Since the wind turbine noise level analyzing by numerical methods or computational fluid dynamics (CFD) could be very challenging and time consuming, soft computing techniques are preferred. To estimate noise level of wind turbine, this paper constructed a process which simulates the wind turbine noise levels in regard to wind speed and sound frequency with adaptive neuro-fuzzy inference system (ANFIS). This intelligent estimator is implemented using Matlab/Simulink and the performances are investigated. The simulation results presented in this paper show the effectiveness of the developed method. PMID:25075621

Adaptive neuro-fuzzy methodology for noise assessment of wind turbine.

Directory of Open Access Journals (Sweden)

Shahaboddin Shamshirband

Full Text Available Wind turbine noise is one of the major obstacles for the widespread use of wind energy. Noise tone can greatly increase the annoyance factor and the negative impact on human health. Noise annoyance caused by wind turbines has become an emerging problem in recent years, due to the rapid increase in number of wind turbines, triggered by sustainable energy goals set forward at the national and international level. Up to now, not all aspects of the generation, propagation and perception of wind turbine noise are well understood. For a modern large wind turbine, aerodynamic noise from the blades is generally considered to be the dominant noise source, provided that mechanical noise is adequately eliminated. The sources of aerodynamic noise can be divided into tonal noise, inflow turbulence noise, and airfoil self-noise. Many analytical and experimental acoustical studies performed the wind turbines. Since the wind turbine noise level analyzing by numerical methods or computational fluid dynamics (CFD could be very challenging and time consuming, soft computing techniques are preferred. To estimate noise level of wind turbine, this paper constructed a process which simulates the wind turbine noise levels in regard to wind speed and sound frequency with adaptive neuro-fuzzy inference system (ANFIS. This intelligent estimator is implemented using Matlab/Simulink and the performances are investigated. The simulation results presented in this paper show the effectiveness of the developed method.

Infrasound and low frequency noise from wind turbines: exposure and health effects

Energy Technology Data Exchange (ETDEWEB)

Bolin, Karl [Marcus Wallenberg Laboratory, Department of Aeronautical and Vehicle Engineering, Kungliga Tekniska Hoegskolan (Sweden); Bluhm, Goesta; Nilsson, Mats E [Institute of Environmental Medicine, Karolinska Institutet (Sweden); Eriksson, Gabriella, E-mail: kbolin@kth.se [Swedish National Road and Transport Research Institute and Linkoeping University (Sweden)

2011-07-15

Wind turbines emit low frequency noise (LFN) and large turbines generally generate more LFN than small turbines. The dominant source of LFN is the interaction between incoming turbulence and the blades. Measurements suggest that indoor levels of LFN in dwellings typically are within recommended guideline values, provided that the outdoor level does not exceed corresponding guidelines for facade exposure. Three cross-sectional questionnaire studies show that annoyance from wind turbine noise is related to the immission level, but several explanations other than low frequency noise are probable. A statistically significant association between noise levels and self-reported sleep disturbance was found in two of the three studies. It has been suggested that LFN from wind turbines causes other, and more serious, health problems, but empirical support for these claims is lacking.

Research on Darrieus-type hydraulic turbine for extra-low head hydropower utilization

International Nuclear Information System (INIS)

Furukawa, A; Watanabe, S; Okuma, K

2012-01-01

A Darrieus-type turbine has been investigated for extra-low head hydropower utilization. In the present paper, authors'research on Darrieus-type hydraulic turbine is briefly reviewed. The working principle of Darrieus turbine is explained with advantage of its simple structure, at first. Then the fluid-dynamic difference between rotating and linear motions of a blade in a uniform flow is clarified with guiding principle of high performance design of Darrieus turbine. Cavitation problem is also described. Next, effects of duct-casing, consisting of an intake, runner section and draft tube, are discussed and a simplified structure of Darrieus turbine is shown by installing the inlet nozzle. Finally, in the practical use, an adjustment of inlet nozzle section by lowering the inlet nozzle height is proposed when flow rate is varied temporally and seasonally.

Assessment of the turbine trip transient in Cofrentes NPP with TRAC-BF1

International Nuclear Information System (INIS)

Castrillo, F.; Gomez, A.; Gallego, I.

1993-06-01

This report presents the results of the assessment of TRAC-BF1 (G1-J1) code with the model of C. N. Cofrentes for simulation of the transient originated by the manual trip of the main turbine. C. N. Cofrentes is a General Electric designed BWR/6 plant, with a nominal core thermal power of 2894 Mwt, in commercial operation since 1985, owned and operated by Hidroelectrica Espanola, S. A. The plant incorporates all the characteristics of BWR/6 reactors, with two turbine driven FW pumps. As a result of this assessment a model of C. N. Cofrentes has been developed for TRAC-BF1 that fairly reproduces operational transient behavior of the plant. A special purpose code was generated to obtain reactivity coefficients, as required by TRAC-BF1, from the 3D simulator

The effectiveness of heat pumps as part of CCGT-190/220 Tyumen CHP-1

Directory of Open Access Journals (Sweden)

Tretyakova Polina

2017-01-01

Full Text Available The article considers the possibility of increasing the energy efficiency of CCGT-190/220 Tyumen CHP-1 due to the utilization of low-grade heat given off in the condenser unit of the steam turbine. To assess the effectiveness of the proposed system, the indexes of thermal efficiency are given. As a result of a research the following conclusions are received: The heat-transfer agent heat pump, when heated uses low-grade heat TPP and increases heat output, but consumes the electricity. Using a heat pump is effective for a small temperature difference between the condenser and the evaporator. Good example is heating water before chemical treatment. This method is more efficient than using a replacement boiler and it is used in steam selection.

Methods of stabilizing a permanent maglev rotator in heart pumps and other rotary machines

Directory of Open Access Journals (Sweden)

kun-xi qian

2014-10-01

Full Text Available Permanent maglev rotator in a rotary machine could be stabilized according to the author’s experiences, by use of a non-PM (permanent magnetic force acting together with the PM force, and a non-PM bearing functioning together with the PM bearing, or a so-called gyro-effect which can stabilize all rotators including permanent maglev rotator. This paper presents both axially and radially driven permanent maglev centrifugal heart pumps, as well as a permanent maglev turbine machine and an industrially used permanent maglev centrifugal pump. In all this devices permanent maglev rotators achieve stable equilibrium by different approaches described in detail. Finally, the principle exhibition of gyro-effect and the route chart to stabilization of permanent maglev rotator are presented.

Electromagnetic Calculation of Combined Earthing System with Ring Earth Electrode and Vertical Rods for Wind Turbine

Science.gov (United States)

Fujii, Toshiaki; Yasuda, Yoh; Ueda, Toshiaki

With the worldwide spread of wind turbine installations, various problems such as landscape issues, bird strikes and grid connections have arisen. Protection of wind turbines from lightning is cited as one of the main problems. Wind turbines are often struck by lightning because of their open-air locations, such as in mountainous areas, and their special configuration and very-high construction. Especially, low-voltage and control circuits can fail or suffer burnout while blades can incur serious damage if struck by lightning. Wind turbine failures caused by lightning strikes account for approximately 25% of all failures. The problem is regarded as a global one that needs immediate resolution. It is important to understand the impedance characteristics of wind turbine earthing systems from the viewpoint of lightning protection. A report from IEC TR61400-24 recommends a “ring earth electrode”. This was originally defined in IEC 61024 (currently revised and re-numbered as IEC 62305), where such an electrode is recommended to reduce touch and step voltages in households and buildings. IEC TR61400-24 also recommended additional electrodes of vertical or horizontal rods. However, these concepts have not been fully discussed from the viewpoint of its application to wind turbines. To confirm the effect of a combination of a ring earth electrode and additional vertical rods for protection of a wind turbine, this report uses the Finite Difference Time Domain (FDTD) method to present an electromagnetic transient analysis on such a wind turbine earthing system. The results show that an optimal combination can be arranged from viewpoints of lightning protection and construction cost. Thus, this report discusses how to establish a quantitative design methodology of the wind turbine earthing system to provide effective lightning protection.

Impact of Spatial Pumping Patterns on Groundwater Management

Science.gov (United States)

Yin, J.; Tsai, F. T. C.

2017-12-01

Challenges exist to manage groundwater resources while maintaining a balance between groundwater quantity and quality because of anthropogenic pumping activities as well as complex subsurface environment. In this study, to address the impact of spatial pumping pattern on groundwater management, a mixed integer nonlinear multi-objective model is formulated by integrating three objectives within a management framework to: (i) maximize total groundwater withdrawal from potential wells; (ii) minimize total electricity cost for well pumps; and (iii) attain groundwater level at selected monitoring locations as close as possible to the target level. Binary variables are used in the groundwater management model to control the operative status of pumping wells. The NSGA-II is linked with MODFLOW to solve the multi-objective problem. The proposed method is applied to a groundwater management problem in the complex Baton Rouge aquifer system, southeastern Louisiana. Results show that (a) non-dominated trade-off solutions under various spatial distributions of active pumping wells can be achieved. Each solution is optimal with regard to its corresponding objectives; (b) operative status, locations and pumping rates of pumping wells are significant to influence the distribution of hydraulic head, which in turn influence the optimization results; (c) A wide range of optimal solutions is obtained such that decision makers can select the most appropriate solution through negotiation with different stakeholders. This technique is beneficial to finding out the optimal extent to which three objectives including water supply concern, energy concern and subsidence concern can be balanced.

Sea water pumping-up power plant system combined with nuclear power plant

International Nuclear Information System (INIS)

Ichiki, Tadaharu; Tanaka, Masayuki.

1991-01-01

It is difficult to find a site suitable to construction for a sea water pumping-up power plant at a place relatively near the electric power consumption area. Then, a nuclear power plant is set at the sea bottom or the land portion of a sea shore near the power consumption area. A cavity is excavated underground or at the bottom of the sea in the vicinity of the power plant to form a lower pond, and the bottom of the sea, as an upper pond and the lower pond are connected by a water pressure pipe and a water discharge pipe. A pump water turbine is disposed therebetween, to which electric power generator is connected. In addition, an ordinary or emergency cooling facility in the nuclear power plant is constituted such that sea water in the cavity is supplied by a sea water pump. Accordingly, the sea water pumping-up plant system in combination with the nuclear power plant is constituted with no injuring from salts to animals and plants on land in the suburbs of a large city. The cost for facilities for supplying power from a remote power plant to large city areas and power loss are decreased and stable electric power can be supplied. (N.H.)

Ice-Release and Erosion Resistant Materials for Wind Turbines

Science.gov (United States)

Zhang, Wei; Brinn, Cameron; Cook, Alex; Pascual-Marquez, Fernando

2017-11-01

Icing conditions may cause wind turbine generators to partially lose productivity or to be completely shut down to avoid structural damage. At present, commercially available technologies to mitigate this problem consist of expensive, energy hungry heating elements, which costs roughly 70,000 euro per medium size turbine. Conventional passive ice protection coating systems heavily rely on delicate surface structures and expensive materials to create water repellent superhydrophobic / low surface energy surfaces, which have been proven to be ineffective against ice accumulation. The lack of performance among conventional ice protection materials stems from a flaw in the approach to the problem: failure to recognize that water in its liquid form (WATER) and water in its solid form (ICE) are two different things. Something that works for WATER does not automatically work for ICE. Another reason is that many superhydrophobic materials are often reliant upon often fragile micro-structured surfaces to achieve their intended effects. This paper discusses a fundamentally different approach to the creation of a robust, low cost, durable, and multifunctional materials for ice release and erosion resistance. This National Science Foundation sponsored ice-release coating technology holds promise for protecting wind turbine blades and towers, thus potentially increasing reliability for power generation under icing conditions. Because of the vulnerability of wind turbine blades to ice buildup and erosion damages, wind farm facilities stand to reap considerable benefits.

The swirl turbine

Science.gov (United States)

Haluza, M.; Pochylý, F.; Rudolf, P.

2012-11-01

In the article is introduced the new type of the turbine - swirl turbine. This turbine is based on opposite principle than Kaplan turbine. Euler equation is satisfied in the form gHηh = -u2vu2. From this equation is seen, that inflow of liquid into the runner is without rotation and on the outflow is a rotation of liquid opposite of rotation of runner. This turbine is suitable for small head and large discharge. Some constructional variants of this turbine are introduced in the article and theoretical aspects regarding losses in the draft tube. The theory is followed by computational simulations in Fluent and experiments using laser Doppler anemometry.

Improved Formulation for the Optimization of Wind Turbine Placement in a Wind Farm

Directory of Open Access Journals (Sweden)

Zong Woo Geem

2013-01-01

Full Text Available As an alternative to fossil fuels, wind can be considered because it is a renewable and greenhouse gas-free natural resource. When wind power is generated by wind turbines in a wind farm, the optimal placement of turbines is critical because different layouts produce different efficiencies. The objective of the wind turbine placement problem is to maximize the generated power while minimizing the cost in installing the turbines. This study proposes an efficient optimization formulation for the optimal layout of wind turbine placements under the resources (e.g., number of turbines or budget limit by introducing corresponding constraints. The proposed formulation gave users more conveniences in considering resources and budget bounds. After performing the optimization, results were compared using two different methods (branch and bound method and genetic algorithm and two different objective functions.

Turbine system and adapter

Science.gov (United States)

Hogberg, Nicholas Alvin; Garcia-Crespo, Andres Jose

2017-05-30

A turbine system and adapter are disclosed. The adapter includes a turbine attachment portion having a first geometry arranged to receive a corresponding geometry of a wheelpost of a turbine rotor, and a bucket attachment portion having a second geometry arranged to receive a corresponding geometry of a root portion of a non-metallic turbine bucket. Another adapter includes a turbine attachment portion arranged to receive a plurality of wheelposts of a turbine rotor, and a bucket attachment portion arranged to receive a plurality of non-metallic turbine buckets having single dovetail configuration root portions. The turbine system includes a turbine rotor wheel configured to receive metal buckets, at least one adapter secured to at least one wheelpost on the turbine rotor wheel, and at least one non-metallic bucket secured to the at least one adapter.

HIGH EFFICIENCY TURBINE

OpenAIRE

VARMA, VIJAYA KRUSHNA

2012-01-01

Varma designed ultra modern and high efficiency turbines which can use gas, steam or fuels as feed to produce electricity or mechanical work for wide range of usages and applications in industries or at work sites. Varma turbine engines can be used in all types of vehicles. These turbines can also be used in aircraft, ships, battle tanks, dredgers, mining equipment, earth moving machines etc, Salient features of Varma Turbines. 1. Varma turbines are simple in design, easy to manufac...

Utility scale wind turbines on a grid-connected island: A feasibility study

Energy Technology Data Exchange (ETDEWEB)

Dua, Mohit; Manwell, James F.; McGowan, Jon G. [Department of Mechanical and Industrial Engineering, Renewable Energy Research Laboratory (RERL), University of Massachusetts, Amherst, MA 01003 (United States)

2008-04-15

This paper analyzes the technical and economic feasibility of installing utility-scale wind turbines on the Fox Islands, located 12 miles from the coast of Maine in the United States. Three locations on the islands, as well as a near offshore site, are analyzed in detail as potential sites for wind turbine installations. As discussed in this work, the logistic problems of transporting and installing wind turbines on the island require innovative solutions. These include locally available amphibious vessels, which can land turbine components at suitable shallow spots on the island, self-erecting towers, which allow use of a smaller crane for installation, and a special turbine foundation suitable for the local ground conditions. In the economic analysis, in addition to standard life-cycle parameters, renewable energy credits (REC) were also included. This work concludes that the installation of sub-megawatt wind turbines on the island is logistically possible and will lead to a reduction in the cost of electricity to the customers. (author)

Optimal placement of horizontal - and vertical - axis wind turbines in a wind farm for maximum power generation using a genetic algorithm

Energy Technology Data Exchange (ETDEWEB)

Chen, Xiaomin; Agarwal, Ramesh [Department of Mechanical Engineering & Materials Science, Washington University in St. Louis, Jolley Hall, Campus Box 1185, One Brookings Drive, St. Louis, Missouri, 63130 (United States)

2012-07-01

In this paper, we consider the Wind Farm layout optimization problem using a genetic algorithm. Both the Horizontal –Axis Wind Turbines (HAWT) and Vertical-Axis Wind Turbines (VAWT) are considered. The goal of the optimization problem is to optimally position the turbines within the wind farm such that the wake effects are minimized and the power production is maximized. The reasonably accurate modeling of the turbine wake is critical in determination of the optimal layout of the turbines and the power generated. For HAWT, two wake models are considered; both are found to give similar answers. For VAWT, a very simple wake model is employed.

Vibration monitoring of large vertical pumps via a remote satellite station

International Nuclear Information System (INIS)

Cook, S.A.; Crowe, R.D.; Roblyer, S.P.; Toffer, H.

1985-01-01