WorldWideScience
1

Hydraulically powered dissimilar teleoperated system controller design  

International Nuclear Information System (INIS)

This paper will address two issues associated with the implementation of a hydraulically powered dissimilar master-slave teleoperated system. These issues are the overall system control architecture and the design of robust hydraulic servo controllers for the position control problem. Finally, a discussion of overall system performance on an actual teleoperated system will be presented

2

Hydraulically powered dissimilar teleoperated system controller design  

Energy Technology Data Exchange (ETDEWEB)

This paper will address two issues associated with the implementation of a hydraulically powered dissimilar master-slave teleoperated system. These issues are the overall system control architecture and the design of robust hydraulic servo controllers for the position control problem. Finally, a discussion of overall system performance on an actual teleoperated system will be presented.

Jansen, J.F.; Kress, R.L.

1996-04-01

3

Highly reliable electro-hydraulic control system  

International Nuclear Information System (INIS)

The unscheduled shutdown of nuclear power stations disturbs power system, and exerts large influence on power generation cost due to the lowering of capacity ratio; therefore, high reliability is required for the control system of nuclear power stations. Toshiba Corp. has exerted effort to improve the reliability of the control system of power stations, and in this report, the electro-hydraulic control system for the turbines of nuclear power stations is described. The main functions of the electro-hydraulic control system are the control of main steam pressure with steam regulation valves and turbine bypass valves, the control of turbine speed and load, the prevention of turbine overspeed, the protection of turbines and so on. The system is composed of pressure sensors and a speed sensor, the control board containing the electronic circuits for control computation and protective sequence, the oil cylinders, servo valves and opening detectors of the valves for control, a high pressure oil hydraulic machine and piping, the operating panel and so on. The main features are the adoption of tripling intermediate value selection method, the multiplying of protection sensors and the adoption of 2 out of 3 trip logic, the multiplying of power sources, the improvement of the reliability of electronic circuit hardware and oil hydraulic system. (Kako, I.)

4

Hydraulic oil control system for transformer stations  

International Nuclear Information System (INIS)

'Full text:' Electrical oil control systems are commonly used to contain large volumes of spilled oil in transformer stations. Specially calibrated floats, some of which are designed to float only in oil and others only in water, are used in combination with a pump to contain oil at the catch basin below a transformer station.This electrical control system requires frequent maintenance and inspections to ensure the electrical system is not affected by any electrical surges. Also the floats need to be inspected and cleaned frequently to prevent oil or grit build up that may affect the systems' ability to contain oil.Recognizing the limitations of electrical oil control systems, Hydro One is investigating alternative control systems. A hydraulic oil control system is being investigated as an alternative which can backup oil in a containment area while allowing any water entering the containment area to pass through. Figure 1 shows a schematic of a bench-top model tested at Ryerson University. Oil and water separation occurs within the double-piped column. Oil and water are allowed to enter the external pipe column but only water is allowed to exit the internal pipe column. The internal pipe column is designed to generate enough hydrostatic pressure to ensure the oil is contained in the external pipe column.The hydraulic oil control system provides a reliable control mechanism and requires less maintenance compared to that of the electrical control system. Since the hydr electrical control system. Since the hydraulic oil control system has no moving parts, nor would any parts that require electricity, it is not affected by electrical surges such as lightening.The maintenance requirements of the hydraulic oil control system are: the removal of any oil and grit from the catch basin, and the occasional visual inspection for any crack or clogs in the system. (author)

5

Control issues for a hydraulically powered dissimilar teleoperated system  

International Nuclear Information System (INIS)

This paper will address two issues associated with the implementation of a hydraulically powered dissimilar master-slave teleoperated system. These issues are the overall system control architecture and the design of robust hydraulic servo controllers for the position control problem. Finally, a discussion of overall system performance on an actual teleoperated system will be presented. (Schilling's Titan II hydraulic manipulators are the slave manipulators and the master manipulators are from the Oak Ridge National Laboratory-developed Advanced Servo Manipulator.)

6

Control issues for a hydraulically powered dissimilar teleoperated system  

Energy Technology Data Exchange (ETDEWEB)

This paper will address two issues associated with the implementation of a hydraulically powered dissimilar master-slave teleoperated system. These issues are the overall system control architecture and the design of robust hydraulic servo controllers for the position control problem. Finally, a discussion of overall system performance on an actual teleoperated system will be presented. (Schilling`s Titan II hydraulic manipulators are the slave manipulators and the master manipulators are from the Oak Ridge National Laboratory-developed Advanced Servo Manipulator.)

Jansen, J.F.; Kress, R.L.

1995-12-31

7

Design of Transputer Controllers for Hydraulic Actuator Systems.  

DEFF Research Database (Denmark)

The paper deals with how transputers can be applied for fast controllers for hydraulic actuator systems. A general transputer-based control systems including a data acquisition transputer subsystem is presented. An application case: development of a mechatronic test facility with a fast hydraulic test robot controlled by a transputer-basec controller is presented. Some experimental path-tracking results with adaptive control algorithms are presented and discussed. The results confirm that transputers have significant advantages for intelligent control of actuator systems and robots for high speed and precision tasks.

Conrad, Finn

1996-01-01

8

Primary speed control systems for hydraulic units  

Energy Technology Data Exchange (ETDEWEB)

Hydropower stations have specific features that make them quite different from the thermal power plants, i.e. generators of comparatively simple design, inertia of the liquid veina, entirely automatized operation, geographic location, etc. The speed governing systems of the hydropower units have to make the units participating to the primary frequency adjustment and ensuring the stability. Specific lay out are developed in order to improve the frequency response versus the time with various disturbance amplitude. The analysis of experimental and simulation results shown a good coincidence between the curves of the frequency recovery versus the time. The modern speed governors are designed with special circuits to perform the self-adaptation of their stabilizing parameters; a wide knowledge of the hydraulic behaviour of the machines is a prior condition to the determination of the criteria used.

Avenier, R.

1985-12-01

9

Flow versus pressure control of pumps in mobile hydraulic systems  

OpenAIRE

This work studies an innovative working hydraulic system design for mobile applications, referred to as flow control. The fundamental difference compared to load-sensing systems is that the pump is controlled based on the operator’s command signals rather than feedback signals from the loads. This control approach enables higher energy efficiency since the pressure difference between pump and load is given by the system resistance rather than a prescribed pump pressure margin. Furthermore, ...

Axin, Mikael; Eriksson, Bjo?rn; Krus, Petter

2014-01-01

10

Control optimization of variable speed reversible hydraulic system  

OpenAIRE

The purpose of this thesis is to optimize the control command of a reversible variable speed hydraulic system. The approach is first treated by dynamic simulation and then finish by experimental validation on hybrid physical model based on real-time emulation (PHIL). The simulation part concerns the modeling of different elements such as micro-hydro turbine, generator and the power electronics interface and the development of control laws and synthesis of different regulators. Two control str...

Belhadji, Lakhdar

2013-01-01

11

Nonlinear, Adaptive and Fault-tolerant Control for Electro-hydraulic Servo Systems  

OpenAIRE

Fluid power systems have been in use since 1795 with the rst hydraulic press patented by Joseph Bramah and today form the basis of many industries. Electro hydraulic servo systems are uid power systems controlled in closed-loop. They transform reference input signals into a set of movements in hydraulic actuators (cylinders or motors) by the means of hydraulic uid under pressure. With the development of computing power and control techniques during the last few decad...

Choux, Martin; Blanke, Mogens; Hovland, Geir

2011-01-01

12

Fuzzy Immune PID Control of Hydraulic System Based on PSO Algorithm  

OpenAIRE

This paper takes the permanent magnet servo motor-driven hydraulic system as the research object. The hydraulic system power source uses servo motor instead of the original asynchronous motor, becoming a new energy-saving, fast response, and easy to realize closed-loop control hydraulic power systems. Aiming at variability of the load for the hydraulic system, immune algorithm is introduced to incremental P...

Ma Yu; Gu Lichen

2013-01-01

13

Hydraulic engine valve actuation system including independent feedback control  

Science.gov (United States)

A hydraulic valve actuation assembly may include a housing, a piston, a supply control valve, a closing control valve, and an opening control valve. The housing may define a first fluid chamber, a second fluid chamber, and a third fluid chamber. The piston may be axially secured to an engine valve and located within the first, second and third fluid chambers. The supply control valve may control a hydraulic fluid supply to the piston. The closing control valve may be located between the supply control valve and the second fluid chamber and may control fluid flow from the second fluid chamber to the supply control valve. The opening control valve may be located between the supply control valve and the second fluid chamber and may control fluid flow from the supply control valve to the second fluid chamber.

Marriott, Craig D

2013-06-04

14

Hydraulic-Ball (HY-Ball) Control System  

International Nuclear Information System (INIS)

The Hy-Ball control system consists of a large number of small tubes vertically penetrating the active core region; the tubes contain movable poison elements (either spherical or cylindrical), which are hydraulically lifted upward from within the active core region to increase core reactivity. Reactor water is the actuating fluid. Hy-Ball columns occupy fuel-element lattice positions in a homogeneous fuel-element configuration. This configuration, with finely subdivided control elements, practically eliminates local water-hole power peaking and provides good control of the radial power distribution. By limitation of the amount of reactivity controlled by a single Hy-Ball column assembly to 0.1% or less, it is unnecessary to operate the poison elements in any position other than either the fully-inserted or fully-withdrawn positions. Elimination of intermediate positions results in simplicity of the system and avoids the inherent axial power perturbation resulting from partially inserted control elements. Physics studies indicate that up to about 40% more power can be obtained from a Hy-Ball-controlled core than from a core with conventional control rods. Tests simulating all reactor operating conditions except radiation are being performed for evaluation of costs, operational characteristics and long-term reliability effects. (author)

15

Modification Of Control System For Flow On Hydraulic Rabbit System Facility  

International Nuclear Information System (INIS)

Had been modification control system on the hydraulic rabbit system facility is installed at floor +8 m in reactor building GA. Siwabessy. On the hydraulic rabbit system is used water for media transfer and media cooling from hot cell to irradiation position or from irradiation position to hot cell. Flow water to sent capsule target about 55 liters/minute. Flow meter type RS No. 185-9926 is installed in hydraulic rabbit system. The flow meters have specification : flow rate 5 to 100 liters/minute, maximum working pressure 10 bar, temperature range 5 to 60 oC and viscosity range 10 to 200 centistokes. The flow meter is installed on the pipe line upper pump of hydraulic rabbit system facility in room no.0626 floor +8 meter reactor building. After the flow meter installed, flow rate on the hydraulic rabbit system can measure direct, flow rate can be adjusted and result same as on the monitor

16

Optimal controller for vibration isolation system with controlled hydraulic damper by piezoelectric stack  

Science.gov (United States)

Piezoelectric stacks are increasingly applicable in various branches of engineering. Their work is based upon the inverse piezoelectric effect. Piezoelectric stacks are characterised by very good dynamic properties. In the presented paper a piezoelectric stack was used as an element in an operating hydraulic damper. The efficiency of a hydraulic damper was tested in a semi-active vibration isolation system. A mathematical model of a vibration isolation system with a hydraulic damper was presented. In the model it was taken into account that there is a non-linear relationship between force and velocity occurring in a hydraulic damper. Based upon the mathematical model, the synthesis of an optimum controller for vibration isolation system was carried out, taking into account the harmonic character of dependence of excitation signal from the road. Results of the simulated numeric experiments for the vibration isolation system with an optimum controller were presented.

Sibielak, Marek

2013-03-01

17

Direct Drive Electro-hydraulic Servo Control System Design with Self-Tuning Fuzzy PID Controller  

OpenAIRE

According to the nonlinear and time-varying uncertainty characteristics of direct drive electro-hydraulic servo control system, a self-tuning fuzzy PID control method with speed change integral and differential ahead optimizing operator is put forward by combining fuzzy inference and traditional PID control in this paper.The rule of fuzzy logic is designed, the membership function of the fuzzy subsets is determined and lookup table method is used to correcte the PID parameters in real-time. F...

Wang Yeqin

2013-01-01

18

Research of the Electro-hydraulic Servo System Based on RBF Fuzzy Neural Network Controller  

Directory of Open Access Journals (Sweden)

Full Text Available This article describes the composition and working principle of electro-hydraulic position servo control system, and establishes a systematic mathematical model. This article presents a controller which is based on Fuzzy neural networks for an electro-hydraulic speed governor. The design process of the RBF Fuzzy neural network control is introduced in detail. This controller which combines the advantages of the Fuzzy control and Neutral networks control can get the best PID parameters by self-adjustment on line. The simulation study proves that this control system has a better adaptability and can improve the control effect greatly.

Huaizhong Chen

2012-09-01

19

Optimization for PID Control Parameters on Hydraulic Servo Control System Based on Artificial Bee Colony Optimization Algorithm  

OpenAIRE

PID control is used widely in hydraulic servo control system. The PID control parameters are very important to performance of hydraulic servo control system and how to find rapidly the optimum values of PID control parameters is very difficult problem. Based on Matlab/simulink software and taking the IATE standards of the optimization design as objective function, a global search optimization method, called Artificial Bee Colony Optimization Algorithm was applied for the o...

Youxin Luo; Xiaoyi Che; Zhaoguo Chen

2012-01-01

20

Co-Simulation Research of the Mechanical-Hydraulic-Control Coupling System of ITER Tractor  

International Nuclear Information System (INIS)

The virtual prototyping models of the mechanical, hydraulic and control system of the ITER tractor were built with CATIA, ADAMS and MATLAB/Simulink respectively according to its heavy load and high precision characteristics, and the data transfer between the different models was accomplished by the integration interface between different software. Consequently the virtual experimental platform for the multi-disciplinary co-simulation was established. A co-simulation study of the mechanical-hydraulic-control coupling system of the ITER tractor was carried out. The synchronization servo control of parallel hydraulic cylinders was implemented, and the tracking control of the preconcerted trajectory of the hydraulic cylinders was realized on the established experimental platform. This paper presents the optimization design and technology rebuilding for the complicated coupling system with its theoretic foundation and co-simulation virtual experimental platform.

21

Electro Hydraulic Hitch Control  

DEFF Research Database (Denmark)

This paper present and discusses R&D results on electro hydraulic hitch control for off-road vehicle, in particular active damping of oscillation occuring on tractors. The research deals with analysis and control of the oscillations occuring on tractors which are design without any susspection system for agricultural applications and driving for transportation. During tranport phases, the lack of suspension causes the vehicle to bounce and pitch, and makes it difficalt to control. Many systems have been proposed to cope with the oscillatory behavior, and different solutions exist. Common for most of the systems are that they operate on the hydrailc actuators generally providing the motive forces for moving the implement and/or attachment, typically a plough. The basic idea and physical working principle are to use the implement, moveable relative to the vehicle, as a damper mass. The paper includes results on the phenomenon mention above on investigation with special focus on agricultucal tractors. For this purpose a mathematical model and its simulation model descibing the performance of the tractor with its mechanical linkages, and an attached implement. The model is in use as the basis for a parameter research study with emphasis on the requirements to the hitch control by use of hydraulic pressure compensated proportional control valve.

Hansen, M. R.; Andersen, T. O.

2003-01-01

22

Power control units with secondary controlled hydraulic motors - a new concept for application in aircraft high lift systems  

OpenAIRE

Today?s high lift systems of civil transport aircraft are driven by Power Control Units using valve controlled constant displacement hydraulic motors. This concept leads to complex valve blocks, attended by high power losses to realise discrete speed control, positioning and pressure maintaining functionality. The concept of secondary controlled hydraulic motors with variable displacement offers reduction in flow consumption without pressure losses and decreases the complexity of the valve b...

Biedermann, Olaf; Geerling, Gerhard

1998-01-01

23

Nonlinear, Adaptive and Fault-tolerant Control for Electro-hydraulic Servo Systems  

DEFF Research Database (Denmark)

Fluid power systems have been in use since 1795 with the rst hydraulic press patented by Joseph Bramah and today form the basis of many industries. Electro hydraulic servo systems are uid power systems controlled in closed-loop. They transform reference input signals into a set of movements in hydraulic actuators (cylinders or motors) by the means of hydraulic uid under pressure. With the development of computing power and control techniques during the last few decades, they are used increasingly in many industrial elds which require high actuation forces within limited space. However, despite numerous attractive properties, hydraulic systems are always subject to potential leakages in their components, friction variation in their hydraulic actuators and deciency in their sensors. These violations of normal behaviour reduce the system performances and can lead to system failure if they are not detected early and handled. Moreover, the task of controlling electro hydraulic systems for high performance operations is challenging due to the highly nonlinear behaviour of such systems and the large amount of uncertainties present in their models. This thesis focuses on nonlinear adaptive fault-tolerant control for a representative electro hydraulic servo controlled motion system. The thesis extends existing models of hydraulic systems by considering more detailed dynamics in the servo valve and in the friction inside the hydraulic cylinder. It identies the model parameters using experimental data from a test bed by analysing both the time response to standard input signals and the variation of the outputs with dierent excitation frequencies. The thesis also presents a model that accurately describes the static and dynamic normal behaviour of the system. Further, in this thesis, a fault detector is designed and implemented on the test bed that successfully diagnoses internal or external leakages, friction variations in the actuator or fault related to pressure sensors. The presented algorithm uses the position and pressure measurements to detect and isolate faults, avoiding missed detection and false alarm. The thesis also develops a high performance adaptive nonlinear controller for the hydraulic system which outperforms comparable linear controllers widely used in the industry. Because of the controller adaptivity, uncertainties in the model parameters can be handled. Moreover, a special attention is given to reduce the complexity of the controller in order to demonstrate its real-time implementation. Finally the thesis combines the techniques developed in fault detection and nonlinear control in order to develop an active fault-tolerant controller for electro hydraulic servo systems. In order to maintain overall service and performances as high as possible when a potential fault occurs, the fault-tolerant controlled system prognoses the fault and changes its controller parameters or structure. The consequences of an unexpected fault are avoided, high availability is ensured and the overall safety in electro hydraulic servo systems is increased.

Choux, Martin

2011-01-01

24

Design and experimental research of hydraulic control rod drive system for 5 MW THR  

International Nuclear Information System (INIS)

Hydraulic control rod drive system (HCRDS) is a new device of control rod drive which is different from usual electric-magnetic mechanic drive used for water power nuclear reactor. The coolant(water) is used as actuating medium, pumped by canned-pump, then injected into hydraulic step cylinders which are set in the reactor vessel. The outer tube of the step cylinder will be moving step by step by controling of the flow, driving the neutron absorber. 5MW THR is the first reactor in the world in which the hydraulic step drive system was used. Using of the drive system is for getting better safety, reliability and lower cost. In this paper, the design and experimental research of the system are introduced

25

Modeling and Controller Design of an Electro-Hydraulic Actuator System  

Directory of Open Access Journals (Sweden)

Full Text Available Problem statement: Electro-hydraulic actuators are widely used in motion control application. Its valve needs to be controlled to determine direction of the motion. Mathematical modeling is a description of a system in terms of equations. It can be divided into two parts; physical modeling and system identification. The objective of this study was to obtain mathematical model of an electro-hydraulic system using system identification technique by estimating model using System Identification Toolbox in MATLAB. Approach: Experimental works were done to collect input and output data for model estimation and ARX model was chosen as model structure of the system. The best model was accepted based on the best fit criterion and residuals analysis of autocorrelation and cross correlation of the system input and output. PID controller was designed for the model through simulation in SIMULINK. The controller is tuning by Ziegler-Nichols method. The simulation work was verified by applying the controller to the real system to achieve the best performance of the system. Results: The result showed that the output of the system with controller in simulation mode and experimental works were improved and almost similar. Conclusion/Recommendations: The designed PID controller can be applied to the electro-hydraulic system either in simulation or real-time mode. The self-tuning or automatic tuning controller could be developed in future work to increase the reliability of the PID controller.

M. F. Rahmat

2010-01-01

26

Adaptive Backstepping Control of Nonlinear Hydraulic-Mechanical System Including Valve Dynamics  

Directory of Open Access Journals (Sweden)

Full Text Available The main contribution of the paper is the development of an adaptive backstepping controller for a nonlinear hydraulic-mechanical system considering valve dynamics. The paper also compares the performance of two variants of an adaptive backstepping tracking controller with a simple PI controller. The results show that the backstepping controller considering valve dynamics achieves significantly better tracking performance than the PI controller, while handling uncertain parameters related to internal leakage, friction, the orifice equation and oil characteristics.

M. Choux

2010-01-01

27

Digital electro-hydraulic control system for nuclear turbine  

International Nuclear Information System (INIS)

The unit capacity of steam turbines for nuclear power generation is very large, accordingly their unexpected stop disturbs power system, and the lowering of their capacity ratio exerts large influence on power generation cost. Therefore, very high reliability is required for turbine EHC controllers which directly control the turbines for nuclear power generation. In order to meet such requirement, Toshiba Corp. has developed high reliability type analog tripled turbine EHC controllers, and delivered them to No. 3 plant in the Fukushima No. 2 Nuclear Power Station and No. 1 plant in the Kashiwazaki Kariwa Nuclear Power Station, Tokyo Electric Power Co., Inc. At present, the trial operation is under way. The development of digital EHC controllers was begun in 1976, and through the digital EHC for a test turbine and that for a small turbine, the digital EHC controllers for the turbines for nuclear power generation were developed. In this paper, the function, constitution, features and maintenance of the digital tripled EHC controllers for the turbines for nuclear power generation, the application of new technology to them, and the confirmation of the control function by simulation are reported. (Kako, I.)

28

Piezoelectric-hydraulic pump based band brake actuation system for automotive transmission control  

Science.gov (United States)

The actuation system of friction elements (such as band brakes) is essential for high quality operations in modern automotive automatic transmissions (in short, ATs). The current band brake actuation system consists of several hydraulic components, including the oil pump, the regulating valve and the control valves. In general, it has been recognized that the current AT band brake actuation system has many limitations. For example, the oil pump and valve body are relatively heavy and complex. Also, the oil pumps induce inherently large drag torque, which affects fuel economy. This research is to overcome these problems of the current system by exploring the utilization of a hybrid type piezo-hydraulic pump device for AT band brake control. This new actuating system integrates a piezo-hydraulic pump to the input of the band brake. Compared with the current systems, this new actuator features much simpler structure, smaller size, and lower weight. This paper describes the development, design and fabrication of the new stand-alone prototype actuator for AT band brake control. An analytical model is developed and validated using experimental data. Performance tests on the hardware and system simulations utilizing the validated model are performed to characterize the new prototype actuator. It is predicted that with increasing of accumulator pressure and driving frequency, the proposed prototype actuating system will satisfy the band brake requirement for AT shift control.

Kim, Gi-Woo; Wang, K. W.

2007-04-01

29

Experiments on scram for hydraulic control rod driving system in utmost accident at normal temperature  

International Nuclear Information System (INIS)

Based on the principle of hydraulic control rod driving system (HCRDS), the paper gives a new scram method, which makes the inside pressure of step cylinder discharge, to solve the scram problem of HCRDS in control rod hang up accident and inversion conditions, and some experiments were carried out with the 1:1 experimental loop of the HCRDS for the 200 MW nuclear heating reactor (NHR-200). The results show that the control rod falls much quickly than that in normal condition. The differential pressure between the outside and inside of step cylinder can reach a large value after the inside pressure of step cylinder discharge. In other word, the hydraulic control rod, which can overcome certain frictional resistance in control rod hang up accident of its gravity in inversion condition, can insert the nuclear reactor core

30

Cascade Controller Including Back-stepping for Hydraulic-Mechanical Systems  

DEFF Research Database (Denmark)

Development of a cascade controller structure including adaptive backstepping for a nonlinear hydraulic-mechanical system is considered in this paper where a dynamic friction (LuGre) model is included to obtain the necessary accuracy. The paper compares the performance of two variants of an adaptive backstepping tracking controller with earlier results. The new control architecture is analysed and enhanced tracking performance is demonstrated when including the extended friction model. The complexity of the backstepping procedure is significantly reduced due to the cascade structure. Hence, the proposed control structure is better suited to real-time implementation. © 2012 IFAC.

Choux, Martin; Hovland, Geir

2012-01-01

31

Parameter-dependent vibration-attenuation controller design for electro-hydraulic actuated linear structural systems  

Science.gov (United States)

The problem of robust active vibration control for a class of electro-hydraulic actuated structural systems with time-delay in the control input channel and parameter uncertainties appearing in all the mass, damping and stiffness matrices is investigated in this paper. First, by introducing a linear varying parameter, the nonlinear system is described as a linear parameter varying (LPV) model. Second, based on this LPV model, an LMI-based condition for the system to be asymptotically stabilized is deduced. By solving these LMIs, a parameter-dependent controller is established for the closedloop system to be stable with a prescribed level of disturbance attenuation. The condition is also extended to the uncertain case. Finally, some numerical simulations demonstrate the satisfying performance of the proposed controller.

Weng, Falu; Mao, Weijie

2012-03-01

32

Design, analysis and control of hydraulic soft yaw system for 5MW wind turbine  

DEFF Research Database (Denmark)

As wind turbines increase in size and the demands for lifetime also increases, new methods of load reduction needs to be examined. One method is to make the yaw system of the turbine soft/flexible and wereby dampen the loads to the system. This paper presents work done on dampening of these loads by active control of a hydraulic yaw system. The control is based on a non-linear and linear model derived based on a concept yaw system for the NREL 5MW wind turbine. The control strategies show a reduction in pressure pulsations under load and it is concluded that the strategie including high-pass pressure feedback is the most suitable for this application.

Stubkier, SØren; Pedersen, Henrik C.

2012-01-01

33

Decoupling Control Research on Test System of Hydraulic Drive Unit of Quadruped Robot Based on Diagonal Matrix Method  

Directory of Open Access Journals (Sweden)

Full Text Available The mathematical model of hydraulic drive unit of quadruped robot was built in this paper. According to the coupling characteristics between position control system and force control system, the decoupling control strategy was realized based on diagonal matrix method in AMESim?. The results of simulation show that using diagonal matrix method can achieve the decoupling control effectively and it can achieve the decoupling control more effectively with the method of not offset pole-zero in the S coordinate. This research can provide theoretical basis for the application of test system of hydraulic drive unit.

Lingxiao Quan

2013-08-01

34

Control strategy of hydraulic/electric synergy system in heavy hybrid vehicles  

International Nuclear Information System (INIS)

Energy consumption and exhaust emissions of hybrid vehicles strongly depend on the energy storage source and the applied control strategy. Heavy vehicles have the characteristics of frequent starts/stops and significant amounts of braking energy, which needs to find a more efficient way to store and use the high power flow. A novel parallel hybrid vehicles configuration consisting of hydraulic/electric synergy system is proposed to overcome the existing drawbacks of single energy storage source in heavy hybrid vehicles. A control strategy combining a logic threshold approach and key parameters optimization algorithm is developed to achieve acceptable vehicle performance while simultaneously maximizing engine fuel economy and maintaining the battery state of charge in its rational operation range at all times. The experimental and simulation results illustrate the potential of the proposed control strategy in terms of fuel economy and in keeping the deviations of SOC at high efficiency range.

35

Thermal hydraulics of the impurity control system for FED/INTOR  

International Nuclear Information System (INIS)

This paper addresses two important aspects of thermal hydraulics related to the design of the impurity control system (limiter and divertor) of the Fusion Engineering Device (FED) and the International Tokamak Reactor (INTOR). The first part of the paper is devoted to the determination of temperature distributions in various combinations of the coating/structural materials proposed for the limiter/divertor of FED and INTOR. The second part of the paper describes the analysis of the tangential motion of the melt layer under the influence of magnetic force during plasma disruption. The results of both analysis provide inputs to the determination of the life time of the limiter (or divertor) which is the most critical problem for the impurity control system as far as engineering and materials consideration is concerned

36

On Application of Second Order Sliding Mode Control to Electro-Hydraulic Systems  

DEFF Research Database (Denmark)

This paper discusses the application of second order mode controls to hydraulic valve-cylinder drives with a special focus on the limitations resulting from nonlinear dynamic effects in flow control valves. Second order sliding mode algorithms appear highly attractive in the successive implementation of sliding mode control, achieving continuous control inputs, while maintaining the main properties of sliding modes. Under certain model assumptions, some of these controllers may even be applied as output feedback controllers. However, intrinsic nonlinear dynamic effects of hydraulic valves such as slew rates and time delays arising in the amplification stages, limits the applicability of such methods, and may lead to partial losses of robustness and limit cycles. These properties are analyzed and experimentally verified, and compensation methods are proposed. The application of the second order sliding algorithm known as the super twisting controller is considered for output feedback control and compared withconventional first order sliding mode control. The controllers under consideration are applied for position tracking control of a hydraulic valve-cylinder drive exhibiting strong variations in inertia- and gravitational loads. Results demonstrate that the super twisting algorithm may be successfully applied for output feedback control of hydraulic valve-cylinder drives, with modifications guaranteeing robust control performance in a small vicinity of the control target.

Schmidt, Lasse; Andersen, Torben Ole

2014-01-01

37

Mechatronic System Design and Intelligent Motion Control of Hydraulic Robots and Machines  

DEFF Research Database (Denmark)

The paper presents an approach and concept to mechatronic system design and intelligent motion control. The Information Technology (IT) offers software and hardware for improvement of R&D Mechatronic Teams to create products and solutions for industrial applications. The latest progress in IT makes integration of an overall design and manufacturing IT- concept feasible and commercially attractive. An IT-tool concept for modelling, simulation and design of mechatronic products and systems is proposed in this paper. It built on results from a Danish mechatronic research program on intelligent motion control as well as from the Esprit project SWING on IT-tools for rapid prototyping of fluid power components and systems. A mechatronic test facility for a DTU-AAU hydraulic robot ¿Thor¿, and a CNC XY-machine table was implemented. The controller applies digital signal processors (DSPs). The DSP controller utilizes the dSPACE System suitable for real-time experimentation, evaluation and validation of control laws and algorithms.

Conrad, Finn; SØrensen, Torben

2003-01-01

38

Hydraulic Yaw System  

DEFF Research Database (Denmark)

As wind turbines increase in size, combined with increased lifetime demands, new methods for load reduction needs to be examined. One method is to make the yaw system of the turbine soft/flexible and hereby dampen the loads to the system, which is the focus of the current paper. By utilizing the HAWC2 aeroelastic code and an extended model of the NREL 5MW turbine combined with a simplified linear model of the turbine, the parameters of the soft yaw system are optimized to reduce loading in critical components. Results shows that a significant reduction in fatigue and extreme loads to the yaw system and rotor shaft when utilizing the soft yaw drive concept compared to the original stiff yaw system. The physical demands of the hydraulic yaw system are furthermore examined for a life time of 20 years. Based on the extrapolated loads, the duty cycles show that it is possible to construct a hydraulic soft yaw system, which is able to reduce the loads on the wind turbine significantly. A full scale hydraulic yaw test rig is available for experiments and tests. The test rig is presented as well as the system schematics of the hydraulic yaw system.

Stubkier, SØren; Pedersen, Henrik C.

39

Free Valve Technology : – Development of a control system for an electronically controlled pneumatic-hydraulic valve actuation system for an automotive engine  

OpenAIRE

This master thesis is a project commissioned by AVL Södertälje Powertrain Engineering AB. The purpose has been to develop a control system for an electronic pneumatic-hydraulic valve actuation system installed in a one cylinder test engine. AVL is an independent company which develops powertrain systems with internal combustion engines as well as instrumentation and test systems. The valve actuation system is to be used in their research and development of internal combustion technology. Th...

Gundersen, Øyvind

2009-01-01

40

Hydraulics of IDEal Irrigation Systems  

OpenAIRE

The hydraulics of IDEal drip irrigation system components were analyzed under controlled laboratory conditions. The results can be used as inputs for the future design of IDEal systems. The valve loss coefficient for the lateral-submain connector valves was determined. The head loss due to friction in the lay-flat laterals can be accurately estimated with standard friction loss equations using a smaller effective diameter based on the wall thickness and inlet pressure head. The equivalent len...

Thompson, Evan

2009-01-01

41

Trends in Modelling, Simulation and Design of Water Hydraulic Systems – Motion Control and Open-Ended Solutions  

DEFF Research Database (Denmark)

The paper presents and discusses a R&D-view on trends in development and best practise in modelling, simulation and design of both low-pressure and high-pressure tap water hydraulic components and systems for motion control as well as open-ended solutions various industrial applications. The focus is on the advantages using ordinary tap water and the range of application areas are illustrated with examples, in particular within the food processing industry, humidification operations, water mist systems for fire fighting, high water pressure cleaners, water moisturising systems for wood processing, lumber drying process and mobile machines and equipment that operate in environmentally sensitive surroundings. Today’s progress in water hydraulics includes electro-water hydraulic proportional valves and servovalves for design of motion control solutions for machines and robots. The remarkable property is that the components operate with pure water from the tap without additives of any kind. Hence water hydraulicstakes the benefit of pure water as fluid being environmentally friendly, easy to clean sanitary design, non-toxic, non-flammable, inexpensive, readily available and easily disposable. The low-pressure tap water hydraulic systems cover up to around 50 bar, and 2-4 kW having a strong potential to compete with pneumatic and electrical solutions in many applications. The high-pressure water hydraulic systems cover typically up to 160 bar pressure from pump and to motors and actuators 140 bar. Recently, dedicated pumps and accessories running with sea-water as fluid are available. A unique solution is to use reverse osmosis to generate drinking water from sea-water, and furthermore for several off-shore applications. Furthermore, tap water hydraulic components of the Nessie® family and examples of measured performance characteristics are presented and the trends in industrial applications and need for future are discussed.

Conrad, Finn Technical University of Denmark,

2006-01-01

42

Hydraulic Motor Driving Variable-Pitch System for Wind Turbine  

Directory of Open Access Journals (Sweden)

Full Text Available The present hydraulic variable-pitch mechanism of wind turbine uses three hydraulic cylinders to drive three crank and connecting rod mechanisms respectively; the blades are moved with the cranks. The hydraulic variable-pitch mechanism has complex structure, occupies a lot of space and its maintenance is trouble. In order to make up for the shortcomings of hydraulic cylinder variable-pitch system, the present hydraulic variable-pitch mechanism should be changed as follows: hydraulic motors are used to drive gears; gears drive blades; the electro-hydraulic proportional valves are used to control hydraulic motors. The hydraulic control part and electrical control part of variable-pitch system is redesigned. The new variable-pitch system is called hydraulic motor driving variable-pitch system. The new variable-pitch system meets the control requirements of blade pitch, makes the structure simple and its application effect is perfect.    

Ye HUANG

2013-11-01

43

Switching sliding mode force tracking control of piezoelectric-hydraulic pump-based friction element actuation systems for automotive transmissions  

Science.gov (United States)

In this study, a nonlinear sliding-mode controller is designed for force tracking of a piezoelectric-hydraulic pump (PHP)-based actuation system, which is developed to replace the current electro-hydraulic actuation systems for automatic transmission (AT) friction elements, such as band brakes or clutches. By utilizing the PHP, one can eliminate the various hydraulic components (oil pump, regulating valve and control valve) in current ATs and achieve a simpler configuration with more efficient operation. With the derived governing equation of motion of the PHP-based actuation system integrated with the friction element (band brake), a switching control law is synthesized based on the sliding-mode theory. To evaluate the effectiveness of the proposed control law, its force tracking performance for the engagement of a friction element during an AT 1\\to 2 up-shift is examined experimentally. It is shown that one can successfully track the desired force trajectory for AT shift control with small tracking error. This study demonstrates the potential of the PHP as a new controllable actuation system for AT friction elements.

Kim, Gi-Woo; Wang, K. W.

2009-08-01

44

Switching sliding mode force tracking control of piezoelectric-hydraulic pump-based friction element actuation systems for automotive transmissions  

International Nuclear Information System (INIS)

In this study, a nonlinear sliding-mode controller is designed for force tracking of a piezoelectric-hydraulic pump (PHP)-based actuation system, which is developed to replace the current electro-hydraulic actuation systems for automatic transmission (AT) friction elements, such as band brakes or clutches. By utilizing the PHP, one can eliminate the various hydraulic components (oil pump, regulating valve and control valve) in current ATs and achieve a simpler configuration with more efficient operation. With the derived governing equation of motion of the PHP-based actuation system integrated with the friction element (band brake), a switching control law is synthesized based on the sliding-mode theory. To evaluate the effectiveness of the proposed control law, its force tracking performance for the engagement of a friction element during an AT 1?2 up-shift is examined experimentally. It is shown that one can successfully track the desired force trajectory for AT shift control with small tracking error. This study demonstrates the potential of the PHP as a new controllable actuation system for AT friction elements

45

Integrating Experiment, Modeling and Design using a Hands on Hydraulic Positioning Laboratory for Mechanical Control Systems Education  

Science.gov (United States)

As part of a laboratory intensive curriculum, Mechanical Engineering students at California Polytechnic State University, San Luis Obispo are required to take a senior level class in Mechanical Control Systems. In addition to three one-hour lectures, students attend a weekly three hour laboratory session where course concepts are reinforced through hands-on modeling and experimentation. This paper describes a newly implemented and innovative laboratory experience which is centered on a hydraulic position control system. Often experiments in Mechanical Controls are heavily influenced by non-linearities such as friction or backlash which cause inexperienced students to lose confidence in linear system modeling as an effective analysis and design tool. A hydraulic system was chosen for this laboratory due to excellent correlation between experimental results and the linear modeling techniques taught in the course. This laboratory experience is designed to integrate linear system modeling techniques, experimentation and data collection, control system design, and design verification through physical testing using a variety of hardware and software tools. The main objectives of the laboratory are to give the students practice and confidence in advanced control system modeling, experience with precision hydraulic positioning systems, practice in designing Proportional-Integral (PI) controllers, exposure to digital control systems and experience and physical understanding of the sometimes dramatic condition of instability. The methodology includes a unique procedure that uses root locus concepts and asks the students to drive the system to instability to determine system parameters. The paper describes the laboratory experience in detail and gives some example results and an assessment of student learning.

Birdsong, Charles; Owen, Frank; Ridgely, John; Widmann, James

2009-08-11

46

?????????????? ????????????? ??????????????? ??????? ??????????? ??????-??????? Mathematical modeling of the wheelchair hydraulic system  

Directory of Open Access Journals (Sweden)

Full Text Available ? ?????? ???????????? ?????????????? ?????? ??????????????? ???????, ?????????????? ?? ?????????? ??????-???????, ??????? ????????? ?????????? ???? ???????? ???? ??????????? ? ??????????? ?? ???????? ??????????? ??????? ??????????, ? ????? ?? ???????? ???????? ????????. ??????????????? ??????? ??????? ???????????? ???????? ?? ?????????? ???????? ??? ???????? ??????????? ?????? ?? ?????????????? ???????????.The article is offered the mathematical model of hydraulic system mounted on the wheelchair, which one allows to determine the angle of the hydraulic motor shaft rotation, according to velocity of the control levers moving as well as the presser drop. The questions of the specific factors influences on the transients are considered.

?. ?. ????????

2013-01-01

47

Hydraulic management of a soil moisture controlled SDI wastewater dispersal system in an Alabama Black Belt soil.  

Science.gov (United States)

Rural areas represent approximately 95% of the 14000 km(2) Alabama Black Belt, an area of widespread Vertisols dominated by clayey, smectitic, shrink-swell soils. These soils are unsuitable for conventional onsite wastewater treatment systems (OWTS) which are nevertheless widely used in this region. In order to provide an alternative wastewater dosing system, an experimental field moisture controlled subsurface drip irrigation (SDI) system was designed and installed as a field trial. The experimental system that integrates a seasonal cropping system was evaluated for two years on a 500-m(2) Houston clay site in west central Alabama from August 2006 to June 2008. The SDI system was designed to start hydraulic dosing only when field moisture was below field capacity. Hydraulic dosing rates fluctuated as expected with higher dosing rates during warm seasons with near zero or zero dosing rates during cold seasons. Lower hydraulic dosing in winter creates the need for at least a two-month waste storage structure which is an insurmountable challenge for rural homeowners. An estimated 30% of dosed water percolated below 45-cm depth during the first summer which included a 30-year historic drought. This massive volume of percolation was presumably the result of preferential flow stimulated by dry weather clay soil cracking. Although water percolation is necessary for OWTS, this massive water percolation loss indicated that this experimental system is not able to effective control soil moisture within its monitoring zone as designed. Overall findings of this study indicated that soil moisture controlled SDI wastewater dosing is not suitable as a standalone system in these Vertisols. However, the experimental soil moisture control system functioned as designed, demonstrating that soil moisture controlled SDI wastewater dosing may find application as a supplement to other wastewater disposal methods that can function during cold seasons. PMID:21621905

He, Jiajie; Dougherty, Mark; Shaw, Joey; Fulton, John; Arriaga, Francisco

2011-10-01

48

Design and Control of a Novel Hydraulically/Pneumatically Actuated Robotic System for MRI-Guided Neurosurgery  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper the design of a novel modular hydraulic/pneumatic actuated tele-robotic system and a new infrastructure for MRI-guided intervention for closed-bore MRI-guided neurosurgery are presented. Candidate neurosurgical procedures enabled by this system would include thermal ablation, radiofrequency ablation, deep brain stimulators, and targeted drug delivery. The major focus is the application of the designed MR-compatible robotic system to MRI-guided brain biopsy. Navigation and operating modules were designed to undertake the alignment and advancement of the surgical needle respectively. The mechanical design and control paradigm are reported.

Walter Kucharczyk

2008-05-01

49

14 CFR 25.1435 - Hydraulic systems.  

Science.gov (United States)

...2010-01-01 2010-01-01 false Hydraulic systems. 25.1435 Section 25...Miscellaneous Equipment § 25.1435 Hydraulic systems. (a) Element design. Each element of the hydraulic system must be designed...

2010-01-01

50

PLC Based Hydraulic Auto Ladle System  

OpenAIRE

In this paper we have implemented a PLC based Hydraulic Auto Ladle System for Casting Department of Victory Precisions Pvt. Ltd. Chakan, Pune. This project work presents the study and design of PLC based Hydraulic Auto Ladle System. Aluminium pouring is the key process in Casting and Forging industry. Different products are manufactured by the company for automobile sector using aluminium. Programmable Logic Controller (PLC) is used for the automation of pouring process. Au...

Amogh Tayade; Anuja Chitre

2014-01-01

51

Development of a quality management system for borehole investigations. (1) Quality assurance and quality control methodology for hydraulic packer testing  

International Nuclear Information System (INIS)

A quality assurance and quality control (QA/QC) system for the hydraulic packer tests has been established based on the surface-based investigations at JAEA's underground research laboratories in Mizunami and Horonobe. The established QA/QC system covers field investigations (data acquisition) and data analysis. For the field investigations, the adopted procedure is selection of a test section based on a detail fluid logging and checking with tally list, followed by inspection of test tools such as pressure transducers and shut-in valves, etc., test method selection using a 'sequential hydraulic test' for deciding appropriate method, and finally data quality confirmation by pressure changes and derivatives on a log-log plots during testing. Test event logs should also be described during testing for traceability. For the test data analysis, a quick analysis for rough estimation of hydraulic parameters, and a detailed analysis using type curve and/or numerical analyses are conducted stepwise. The established QA/QC system has been applied to the recent borehole investigations and its efficiency has been confirmed. (author)

52

A thermo-hydraulic model of the inventory control system for load following in the PBMR / Tawanda Arnold Daniel Matimba  

OpenAIRE

This dissertation is aimed at the development of a thermo-hydraulic model of the Inventory Control System (ICS) for the Pebble Bed Modular Reactor (PBMR), which is a helium cooled nuclear power plant. The model is used as a design and simulation tool. The ICS is a storage facility whose function is to perform load following through helium mass transfer to and from the PBMR p e r cycle. This mass transfer generally uses pressure differential as the driving force. With a view ...

Matimba, Tawanda Arnold Daniel

2004-01-01

53

Robust hydraulic position controller by a fuzzy state controller  

International Nuclear Information System (INIS)

In nuclear industry, one of the most important design considerations of controllers is their robustness. Robustness in this context is defined as the ability of a system to be controlled in a stable way over a wide range of system parameters. Generally the systems to be controlled are linearized, and stability is subsequently proven for this idealized system. By combining classical control theory and fuzzy set theory, a new kind of state controller is proposed and successfully applied to a hydraulic position servo with excellent robustness against variation of system parameters

54

Transputer Control of Hydraulic Actuators and Robots  

DEFF Research Database (Denmark)

Results from a Danish mechatronics research program entitled IMCIA - Intelligent Control and Intelligent Actuators. The objective is development of intelligent actuators for intelligent motion control. A mechatronics test facility with a transputer controlled hydraulic robot suiteable for real-time experiments and evaluation of control laws and algorithms is presented. Concepts of intelligent motion control and intelligent hydraulic actuators are proposed. Promising experimental path-tracking results obtained from model-based adaptive control algorithms are presented and discussed.

Conrad, Finn

1996-01-01

55

Scaling behaviour of pressure driven micro hydraulic systems  

OpenAIRE

This paper presents a lumped network approach for the modelling and design of micro-hydraulic systems. A hydraulic oscillator has been built consisting of hydraulic resistors, capacitors and transistors (pressure controlled valves). The scaling of micro-hydraulic networks consisting of linear resistors, capacitors and inertances has been studied. An important result is that to make smaller networks faster, driving pressures should increase with reducing size.

Tas, N. R.; Lammerink, T. S. J.; Berenschot, J. W.; Elwenspoek, M. C.; Berg, A. Den

2002-01-01

56

Assessment of the reliability of thermal-hydraulic and neutronics parameters of Ghana research reactor-1 control systems  

International Nuclear Information System (INIS)

The thermal-hydraulics and neutronics parameters of GHARR-1 control systems were assessed for its reliability after 18 years of operation using the Micro-Computer Closed Loop System (MCCLS) and original control Console (CC). The MCCLS and some components that control the sensitivity and the reading mechanism of the meters on the control systems have been replaced with new ones over the years, due to ageing, repairs and obsolescence. The results show that when reactor is operated at the different power levels the preset neutron fluxes at the control systems is 1.6 times the neutron fluxes obtained using a flux monitor at the inner irradiation site two of the reactor. The average percentage of deviation of fluxes from the actual preset was 36.5% which compares very well with the reactivity decrease of 36.3% after operating the reactor at critical neutron flux of 1.0 × 109n/cm2s. The reactivity regulators were adjusted to increase the core reactivity to 4 mk and the reactor operated at 15kW. The preset neutron flux at the control systems reduced to 1.07 times the Neutron fluxes obtained using a flux monitor at the inner irradiation site 2 of the reactor. The performance of the current micro - amplifiers in the two independent control instrumentations was assessed at an input current of 10µA. The results showed that the flux registered on both the CC and MCCLS varied by a factor of 1.2. The correlation between neutron flux and power, as well as temperature and power at transient state produced almost the same thermal power at about 20% above the rating power of 30 kW but deviated at lower and higher power ratings. The dynamic test through positive reactivity insertion, demonstrate or confirm the inherent safety of the reactor. (au)

57

Characterization and quenching of friction-induced limit cycles of electro-hydraulic servovalve control systems with transport delay.  

Science.gov (United States)

This paper develops a systematic and straightforward methodology to characterize and quench the friction-induced limit cycle conditions in electro-hydraulic servovalve control systems with transport delay in the transmission line. The nonlinear friction characteristic is linearized by using its corresponding describing function. The delay time in the transmission line, which could accelerate the generation of limit cycles is particularly considered. The stability equation method together with parameter plane method provides a useful tool for the establishment of necessary conditions to sustain a limit cycle directly in the constructed controller coefficient plane. Also, the stable region, the unstable region, and the limit cycle region are identified in the parameter plane. The parameter plane characterizes a clear relationship between limit cycle amplitude, frequency, transport delay, and the controller coefficients to be designed. The stability of the predicted limit cycle is checked by plotting stability curves. The stability of the system is examined when the viscous gain changes with respect to the temperature of the working fluid. A feasible stable region is characterized in the parameter plane to allow a flexible choice of controller gains. The robust prevention of limit cycle is achieved by selecting controller gains from the asymptotic stability region. The predicted results are verified by simulations. It is seen that the friction-induced limit cycles can be effectively predicted, removed, and quenched via the design of the compensator even in the case of viscous gain and delay time variations unconditionally. PMID:20542269

Wang, Yuan-Jay

2010-10-01

58

Improvement of Hydraulic Edge Position Control System by Proportion Sliding Mode of Self-tuning Switching Gain  

Directory of Open Access Journals (Sweden)

Full Text Available Aiming at the problem of tracking performance degradation of hydraulic EPC system caused by time-varying inertia parameters, nonlinear and external disturbances, the proportion sliding mode control of fuzzy self-tuning gain was proposed. The EPC system state space model on deviation parameters was established and the main feedback sliding mode switching algorithm was designed. The fuzzy method was used to dynamically adjust the proportion sliding mode switching gain by product of the switching function and its derivative state and to adaptive compensate for the uncertainty of the system. At the same time to ensure the effectiveness of the design strategy, the controller model and physical model worked together to simulate the actual conditions. The fixed switching gain switch was, respectively greater and smaller and compared with the fuzzy self-tuning gain, in which the latter achieves a fast and coordinated control of chattering. The results show that after comprehensive consideration all interference the system is stable, fast response, high accuracy and to solve chattering problem caused by the traditional large switching gain of proportion sliding mode.

Jin Baoquan

2012-11-01

59

A study on reliability of electro-hydraulic governor control system for large steam turbine in power plant  

International Nuclear Information System (INIS)

In this work, the right management procedure for hydraulic power oil will be discussed and suggested. A thermal power plant turbine should respond to the change of load status. However, to satisfy the frequency of alternating current, the revolution per minute should be kept constant. Therefore, by controlling the flow rate of the steam to the turbine, the governor satisfies the load variation without alternating the revolution per minutes of the turbine. To protect the governor, the hydraulic power unit should be managed carefully by controlling the quality and the flow rate of the oil

60

Hydraulic Yaw System  

OpenAIRE

As wind turbines increase in size, combined with increased lifetime demands, new methods for load reduction needs to be examined. One method is to make the yaw system of the turbine soft/flexible and hereby dampen the loads to the system, which is the focus of the current paper. By utilizing the HAWC2 aeroelastic code and an extended model of the NREL 5MW turbine combined with a simplified linear model of the turbine, the parameters of the soft yaw system are optimized to reduce loading in cr...

Stubkier, Søren; Pedersen, Henrik C.; Mørkholt, M.

2012-01-01

61

Plug & Play Control of Hydraulic Networks  

DEFF Research Database (Denmark)

Typically, control systems are designedwith little or no consideration for possible changes in the structure of the system process to be controlled. In classic control design, a monolithic approach is taken where structural changes in the system process require the development of a new mathematical model of the system and a subsequent redesign of the control system. This process can be expensive and time consuming. Therefore, an attractive alternative is to design the control system such that it automatically reconfigures whenever structural changes occur. This is the aim of the Plug & Play Process Control research program, which the work presented here is a part of. An industrial case study involving a large-scale hydraulic network with non-linear dynamics is studied. The hydraulic network underlies a district heating system, which provides heating water to a number of end-users in a city district. The case study considers a novel approach to the design of district heating systems in which the diameter of the pipes used in the system is reduced in order to reduce the heat losses in the system, thereby making it profitable to provide district heating to areas with low energy demands. The new structure has the additional benefit that structural changes such as the addition or removal of end-users are easily implementable. In this work, the problem of controlling the pressure drop at the end-users to a constant reference value is considered. This is done by the use of pumps located both at the end-users and at designated places across the network. The control architecture which is used consists of a set of decentralized linear control actions. The control actions use only the measurements obtained locally at each end-user. Both proportional and proportional-integral control actions are considered. Some of the work considers control actions which are constrained to non-negative values only. This is due to the fact that the actuators in this type of system typically consist of centrifugal pumps which are only able to deliver non-negative actuation. Other parts of the work consider control actions which have been quantized. That is, they are restricted to piecewise constant signals taking value in a bounded set. This is done in order to facilitate sending the control signals across a finite bandwidth communication network. This is necessary since the actuators in the system are geographically separated from the logic circuitry implementing the control actions. The results presented here consist of a series of global stability results of the closedloop system using the control actions described above. The stability analysis is complicated by the non-linearities present in the system process. Specifically, global practical output regulation can be shown when using proportional control actions, while global asymptotical output regulation can be shown when using proportional-integral control actions. Since the results are global in the state space, it is concluded that the closed-loop system maintains its stability properties when structural changes are implemented.

Jensen, Tom NØrgaard

2012-01-01

62

Saving Energy in Construction Machinery using Displacement Control Hydraulics : Concept Realization and Validation  

OpenAIRE

In the sector of mobile hydraulics, valve controlled systems are predominant. In these systems the load force and speed are adjusted by control valves. In machines where multiple drives are used in parallel at extremely varying loads the energy efficiency of such systems is often compromised over large working regions. Most valve controlled systems also lack the possibility to recuperate potential energy. A different category of hydraulic systems, called displacement controlled hydraulics are...

Heybroek, Kim

2008-01-01

63

System Topology Optimization - An Approach to System Design of Electro-Hydraulic-Mechanical Systems  

DEFF Research Database (Denmark)

The current paper presents an approach to system design of combined electro-hydraulic-mechanical systems. The approach is based on the concurrent handling of the topology as well as the design parameters of the mechanical, hydraulic and controller sub- systems, respectively. Based on an initial design the procedure attempts to find the optimal topology and the related parameters. The topology considerations comprise the type of hydraulic pump, the employment of knee linkages or not as well as the type of hydraulic actuators. The design variables also include the signals to the proportional valve in a number of predefined load cases as well as the hydraulic and mechanical parameters.

Andersen, T. O.; Hansen, M. R.

2003-01-01

64

Hydraulic manipulator design, analysis, and control at Oak Ridge National Laboratory  

International Nuclear Information System (INIS)

To meet the increased payload capacities demanded by present-day tasks, manipulator designers have turned to hydraulics as a means of actuation. Hydraulics have always been the actuator of choice when designing heavy-life construction and mining equipment such as bulldozers, backhoes, and tunneling devices. In order to successfully design, build, and deploy a new hydraulic manipulator (or subsystem) sophisticated modeling, analysis, and control experiments are usually needed. To support the development and deployment of new hydraulic manipulators Oak Ridge National Laboratory (ORNL) has outfitted a significant experimental laboratory and has developed the software capability for research into hydraulic manipulators, hydraulic actuators, hydraulic systems, modeling of hydraulic systems, and hydraulic controls. The hydraulics laboratory at ORNL has three different manipulators. First is a 6-Degree-of-Freedom (6-DoF), multi-planer, teleoperated, flexible controls test bed used for the development of waste tank clean-up manipulator controls, thermal studies, system characterization, and manipulator tracking. Finally, is a human amplifier test bed used for the development of an entire new class of teleoperated systems. To compliment the hardware in the hydraulics laboratory, ORNL has developed a hydraulics simulation capability including a custom package to model the hydraulic systems and manipulators for performance studies and control development. This paper outlines the history of hydraulic manipulator developments at ORNL, describes the hydraulics laboratory, discusses the use of the equipment within the laboratory, and presents some of the initial results from experiments and modeling associated with these hydraulic manipulators. Included are some of the results from the development of the human amplifier/de-amplifier concepts, the characterization of the thermal sensitivity of hydraulic systems, and end-point tracking accuracy studies. Experimental and analytical results are included

65

Hydraulic manipulator design, analysis, and control at Oak Ridge National Laboratory  

Energy Technology Data Exchange (ETDEWEB)

To meet the increased payload capacities demanded by present-day tasks, manipulator designers have turned to hydraulics as a means of actuation. Hydraulics have always been the actuator of choice when designing heavy-life construction and mining equipment such as bulldozers, backhoes, and tunneling devices. In order to successfully design, build, and deploy a new hydraulic manipulator (or subsystem) sophisticated modeling, analysis, and control experiments are usually needed. To support the development and deployment of new hydraulic manipulators Oak Ridge National Laboratory (ORNL) has outfitted a significant experimental laboratory and has developed the software capability for research into hydraulic manipulators, hydraulic actuators, hydraulic systems, modeling of hydraulic systems, and hydraulic controls. The hydraulics laboratory at ORNL has three different manipulators. First is a 6-Degree-of-Freedom (6-DoF), multi-planer, teleoperated, flexible controls test bed used for the development of waste tank clean-up manipulator controls, thermal studies, system characterization, and manipulator tracking. Finally, is a human amplifier test bed used for the development of an entire new class of teleoperated systems. To compliment the hardware in the hydraulics laboratory, ORNL has developed a hydraulics simulation capability including a custom package to model the hydraulic systems and manipulators for performance studies and control development. This paper outlines the history of hydraulic manipulator developments at ORNL, describes the hydraulics laboratory, discusses the use of the equipment within the laboratory, and presents some of the initial results from experiments and modeling associated with these hydraulic manipulators. Included are some of the results from the development of the human amplifier/de-amplifier concepts, the characterization of the thermal sensitivity of hydraulic systems, and end-point tracking accuracy studies. Experimental and analytical results are included.

Kress, R.L.; Jansen, J.F. [Oak Ridge National Lab., TN (United States). Robotics and Process Systems Div.; Love, L.J. [Oak Ridge Inst. for Science and Education, TN (United States); Basher, A.M.H. [South Carolina State Univ., Orangeburg, SC (United States)

1996-09-01

66

Dynamic behavior of upper hydraulic drive control rod  

Energy Technology Data Exchange (ETDEWEB)

A 200 MW nuclear heating reactor (NHR) was developed based on the 5 MW testing heating reactor (THR-5). In order to improve its features, the INET was used to optimize its structure design. One task was to design the upper hydraulic drive control rod, which is located at the upper part of the reactor core, so that the fuel rod in each corner of the bundle will not be removed as they are in the THR-5. A program based on the method of characteristics was run to investigate the dynamic behavior of the upper hydraulic control rod drive system. The steady-state and dynamic characteristics of the control rod were studied. The influence of the reactor temperature and structure parameters on the operation reliability was investigated. Finally the optimal design parameters of the upper hydraulic drive control rod were obtained.

Li Xiaotian [Institute of Nuclear and New Energy Technology, Beijing 100084 (China)]. E-mail: lixiaotian@tsinghua.edu.cn; He Shuyan [Institute of Nuclear and New Energy Technology, Beijing 100084 (China)

2006-12-15

67

Experimental Investigation on the Basic Law of Hydraulic Fracturing After Water Pressure Control Blasting  

Science.gov (United States)

Because of the advantages of integrating water pressure blasting and hydraulic fracturing, the use of hydraulic fracturing after water pressure control blasting is a method that is used to fully transform the structure of a coal-rock mass by increasing the number and range of hydraulic cracks. An experiment to study hydraulic fracturing after water pressure blasting on cement mortar samples (300 × 300 × 300 mm3) was conducted using a large-sized true triaxial hydraulic fracturing experimental system. A traditional hydraulic fracturing experiment was also performed for comparison. The experimental results show that water pressure blasting produces many blasting cracks, and follow-up hydraulic fracturing forces blasting cracks to propagate further and to form numerous multidirectional hydraulic cracks. Four macroscopic main hydraulic cracks in total were noted along the borehole axial and radial directions on the sample surfaces. Axial and radial main failure planes induced by macroscopic main hydraulic cracks split the sample into three big parts. Meanwhile, numerous local hydraulic cracks were formed on the main failure planes, in different directions and of different types. Local hydraulic cracks are mainly of three types: local hydraulic crack bands, local branched hydraulic cracks, and axial layered cracks. Because local hydraulic cracks produce multiple local layered failure planes and lamellar ruptures inside the sample, the integrity of the sample decreases greatly. The formation and propagation process of many multidirectional hydraulic cracks is affected by a combination of water pressure blasting, water pressure of fracturing, and the stress field of the surrounding rock. To a certain degree, the stress field of surrounding rock guides the formation and propagation process of the blasting crack and the follow-up hydraulic crack. Following hydraulic fracturing that has been conducted after water pressure blasting, the integrity of the sample is found to be far lower than after traditional hydraulic fracturing; moreover, both the water injection volume and water injection pressure for hydraulic fracturing after water pressure blasting are much higher than they are for traditional hydraulic fracturing.

Huang, Bingxiang; Li, Pengfeng; Ma, Jian; Chen, Shuliang

2014-07-01

68

Simulation and control of an electro-hydraulic actuated clutch  

Science.gov (United States)

The basic function of any type of automotive transmission is to transfer the engine torque to the vehicle with the desired ratio smoothly and efficiently and the most common control devices inside the transmission are clutches and hydraulic pistons. The automatic control of the clutch engagement plays a crucial role in Automatic Manual Transmission (AMT) vehicles, being seen as an increasingly important enabling technology for the automotive industry. It has a major role in automatic gear shifting and traction control for improved safety, drivability and comfort and, at the same time, for fuel economy. In this paper, a model for a wet clutch actuated by an electro-hydraulic valve used by Volkswagen for automatic transmissions is presented. Starting from the developed model, a simulator was implemented in Matlab/Simulink and the model was validated against data obtained from a test-bench provided by Continental Automotive Romania, which includes the Volkswagen wet clutch actuated by the electro-hydraulic valve. Then, a predictive control strategy is applied to the model of the electro-hydraulic actuated clutch with the aims of controlling the clutch piston displacement and decreasing the influence of the network-induced delays on the control performances. The simulation results obtained with the proposed method are compared with the ones obtained with different networked controllers and it is shown that the strategy proposed in this paper can indeed improve the performances of the control system.

Balau, Andreea-Elena; Caruntu, Constantin-Florin; Lazar, Corneliu

2011-08-01

69

Intelligent PI Fuzzy Control of An Electro-Hydraulic Manipulator  

Directory of Open Access Journals (Sweden)

Full Text Available The development of a fuzzy-logic controller for a class of industrial hydraulic manipulator is described. The main element of the controller is a PI-type fuzzy control technique which utilizes a simple set of membership functions and rules to meet the basic control requirements of such robots. Using the triangle shaped membership function, the position of the servocylinder was successfully controlled. When the system parameter is altered, the control algorithm is shown to be robust and more faster compared to the traditional PID controller. The robustness and tracking ability of the controller were demonstrated through simulations.

Ayman A. Aly

2012-06-01

70

14 CFR 33.72 - Hydraulic actuating systems.  

Science.gov (United States)

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

2010-01-01

71

49 CFR 570.55 - Hydraulic brake system.  

Science.gov (United States)

...2010-10-01 2010-10-01 false Hydraulic brake system. 570.55 Section...Than 10,000 Pounds § 570.55 Hydraulic brake system. The following requirements apply to vehicles with hydraulic brake systems. (a) Brake...

2010-10-01

72

Thermal-hydraulic unreliability of passive systems  

International Nuclear Information System (INIS)

Advanced light water reactor (LWR) like AP600 and the simplified boiling water reactor use passive safety systems for accident prevention and mitigation. Because these systems rely on natural forces for their operation, their unavailability due to hardware failures and human error is significantly smaller than that of active systems. However, the coolant flows predicted to be delivered by these systems can be subject to significant uncertainties, which in turn can lead to a significant uncertainty in the predicted thermal-hydraulic performance of the plant under accident conditions. Because of these uncertainties, there is a probability that an accident sequence for which a best-estimate thermal-hydraulic analysis predicts no core damage (success sequence) may actually lead to core damage. For brevity, this probability will be called thermal-hydraulic unreliability. The assessment of this unreliability for all the success sequences requires very expensive computations. Moreover, the computational cost increases drastically as the required thermal-hydraulic reliability increases. The required computational effort can be greatly reduced if a bounding approach can be used that either eliminates the need to compute thermal-hydraulic unreliabilities, or it leads to the analysis of a few bounding sequences for which the required thermal-hydraulic reliability is relatively small. The objective of this paper is to present such an approach and determine the order of magnitude oach and determine the order of magnitude of the thermal-hydraulic unreliabilities that may have to be computed

73

Thermal-hydraulic unreliability of passive systems  

International Nuclear Information System (INIS)

Advanced light water reactor designs like AP600 and the simplified boiling water reactor (SBWR) use passive safety systems for accident prevention and mitigation. Because these systems rely on natural forces for their operation, their unavailability due to hardware failures and human error is significantly smaller than that of active systems. However, the coolant flows predicted to be delivered by these systems can be subject to significant uncertainties, which in turn can lead to a significant uncertainty in the predicted thermal-hydraulic performance of the plant under accident conditions. Because of these uncertainties, there is a probability that an accident sequence for which a best estimate thermal-hydraulic analysis predicts no core damage (success sequence) may actually lead to core damage. For brevity, this probability will be called thermal-hydraulic unreliability. The assessment of this unreliability for all the success sequences requires very expensive computations. Moreover, the computational cost increases drastically as the required thermal-hydraulic reliability increases. The required computational effort can be greatly reduced if a bounding approach can be used that either eliminates the need to compute thermal-hydraulic unreliabilities, or it leads to the analysis of a few bounding sequences for which the required thermal-hydraulic reliability is relatively small. The objective of this paper is to present such an approach and determine the order of magnitude of the thermal-hydraulic unreliabilities that may have to be computed

74

Hydraulics  

Science.gov (United States)

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

75

Computerized hydraulic scanning system for quantitative non destructive examination  

International Nuclear Information System (INIS)

A hydraulic scanning system with five degrees of freedom is described. It is primarily designed as a universal system for fast and accurate ultrasonic inspection of materials for their internal variation in properties. The whole system is controlled by a minicomputer which also is used for evaluating and presenting of the results of the inspection. (author)

76

Optimal control based design of output coupled power split hydraulic hybrid  

OpenAIRE

Hydraulic hybrid power trains/vehicles (HHV) achieve higher power density, better utilization of regenerative braking due to faster storage of brake energy in hydraulic accumulators, much lower installation cost and no recycling problems compared to its electric counterpart. The goal of this thesis is to investigate the potential of fuel savings of hydraulic hybrid power trains compared to electric hybrid vehicles. This thesis utilizes optimal control for both system design and control. As a ...

Zhao, Minming

2012-01-01

77

Adaptive Sliding Mode Control for Hydraulic Drives : A New Approach  

DEFF Research Database (Denmark)

This paper presents a new adaptive sliding mode controller generally applicable for position tracking control of electro-hydraulic valve-cylinder drives (VCD’s). The proposed control scheme requires limited knowledge on system parameters, and employs only piston- and valve spool position feedback. The main target is to overcome problems with linear controllers deteriorating performance due to the inherent nonlinear nature of such systems, without requiring extensive knowledge on system parameters nor advanced control theory. In order to accomplish this task, an integral sliding mode controller employing parameter adaption through a recursive algorithm is presented. This is based on a reduced order model approximation of a VCD with unmatched valve flow- and cylinder asymmetries. Bounds on parameters are obtained despite lack of parameter knowledge, and the proposed controller demonstrates improved position tracking performance and robustness / adaptability compared with a conventional feedforward-PI controller, when subjected to perturbations in supply pressure and coulomb friction.

Schmidt, Lasse; Andersen, Torben Ole

2013-01-01

78

Controlling a negative loaded hydraulic cylinder using pressure feedback  

DEFF Research Database (Denmark)

This paper is concerned with the inherent oscillatory nature of pressure compensated velocity control of a hydraulic cylinder subjected to a negative load and suspended by means of an over-center valve. Initially, a linearized stability analysis of such a hydraulic circuit is carried out clearly showing that without extra measures such a system will be unstable in a substantial part of the cylinder stroke. The stability criterion is expressed in hard quantities: Cylinder volumes, cylinder area ratio and overcenter valve pilot area ratio. A pressure feed back scheme that has as target to maintain the high pass filtered pressure gradient equal tozero is introduced. It yields lead compensation with a markedly improved performance. The sizing of the filter is described taking into account the bandwidth of the directional control valve. The suggested control scheme is implemented and examined in a nonlinear time domain simulation model validating the linear stability analysis.

Hansen, M.R.; Andersen, T.O.

2010-01-01

79

A coupled analysis of system thermal-hydraulics and three-dimensional reactor kinetics for a 12-finger control element assembly drop event in a PWR plant  

International Nuclear Information System (INIS)

A coupled system thermal-hydraulics (T-H) and three-dimensional reactor kinetics code, MARS/MASTER, was developed to attain more accurate predictions for nuclear system transients that involve strong interactions between neutronic and T-H phenomena. In this paper, a 12-finger control element assembly (CEA) drop event in a two-loop pressurized water reactor (PWR) plant under a full power condition was analyzed, where the 12-finger CEA that is nearest to the hot leg of Loop 2 is assumed to incidentally drop. This instantaneously results in an asymmetric radial power distribution and, in turn, asymmetric loop behavior, which may lead to a reactor trip due to a low departure from nucleate boiling (DNB) ratio at the intact side of the core or an excessive difference between the cold leg coolant temperatures. This event clearly requires a coupled calculation of system T-H and three-dimensional reactor kinetics to realistically investigate the thermal-hydraulic behavior of the reactor core. A simple theoretical modeling is also devised to evaluate the cold leg temperature difference under a quasi-steady state.

80

A Novel Energy Recovery System for Parallel Hybrid Hydraulic Excavator  

OpenAIRE

Hydraulic excavator energy saving is important to relieve source shortage and protect environment. This paper mainly discusses the energy saving for the hybrid hydraulic excavator. By analyzing the excess energy of three hydraulic cylinders in the conventional hydraulic excavator, a new boom potential energy recovery system is proposed. The mathematical models of the main components including boom cylinder, hydraulic motor, and hydraulic accumulator are built. The natural frequency of the pro...

Wei Li; Baoyu Cao; Zhencai Zhu; Guoan Chen

2014-01-01

81

Hydraulic Motor Driving Variable-Pitch System for Wind Turbine  

OpenAIRE

The present hydraulic variable-pitch mechanism of wind turbine uses three hydraulic cylinders to drive three crank and connecting rod mechanisms respectively; the blades are moved with the cranks. The hydraulic variable-pitch mechanism has complex structure, occupies a lot of space and its maintenance is trouble. In order to make up for the shortcomings of hydraulic cylinder variable-pitch system, the present hydraulic variable-pitch mechanism should be changed as follows: hydraulic motors ar...

Huang, Ye; Qi, Jibao

2013-01-01

82

Tracking control of the hydraulically actuated flexible manipulator  

International Nuclear Information System (INIS)

The remediation of single-shell radioactive waste storage tanks is one of the urgent tasks of the Department of Energy that challenge state-of-the-art equipment and methods. The use of long-reach manipulators is being seriously considered for this remediation task. Because high payload capacity and high length-to-cross-section ratio requirements, these long-reach manipulator systems are expected to use hydraulic actuators and to exhibit significant structural flexibility. The controller has been designed to compensate for the hydraulic actuator dynamics by using a load-compensated velocity feedforward loop and to increase the bandwidth by using a pressure feed backloop. Shaping filter techniques have been applied as a feedforward controller to avoid structural vibrations during operation. Among various types of shaping filter methods investigated an approach, referred to as a ''feedforward simulation filter'' that uses embedded simulation, has been presented

83

Thermal Equilibrium of a Hydraulic Driving System  

Directory of Open Access Journals (Sweden)

Full Text Available To put into evidence the consequence of the energetic losses that appears in a hydraulic driving systems and to evaluate how does the system performance and reliability are strongly affected by the temperature increase due-to the flowing fluid, in this study a thermal analysis is presented for improving the possibility of developing a practical and simplified method for establishing the optimum working temperature at any instant time. Focus is on computational methods that to be used for controlling the working temperature around the limit of admissible temperature, if the working temperature exceeds this limit, the fluid properties alteration will occur rapidly and a slow deterioration in the internal working parts of the system is expected, based on the failure rule rate that doubles for every 10?C of a temperature increase. Heat load duration is evaluated for both short and long operation periods, in which thermal equations are introduced to describe the conduction, convection and radiation modes of the heat transfer for the given mode of operation .The main conclusion of this study draws an important attention, that must be taken into account even during the first stages of designing such systems, in order to establish the optimum dimensions for the heat exchanger solution, as a design option when required for reducing the heat load for satisfying the needed working temperature and then keeping the system within the energy balance condition

Tarawneh S. Muafag

2004-01-01

84

FOREWORD: 26th IAHR Symposium on Hydraulic Machinery and Systems  

Science.gov (United States)

The 26th IAHR Symposium on Hydraulic Machinery and Systems, will be held in Beijing, China, 19-23 August 2012. It is jointly organized by Tsinghua University, State Key Laboratory of Hydro Science and Hydraulic Engineering, China, Jiangsu University, Xi'an University of Technology, China Agricultural University, National Engineering Research Center of Hydropower Equipment and Dongfang Electric Machinery Co., Ltd. It is the second time that China hosts such a symposium. By the end of 2011, the China electrical power system had a total of 1 050 GW installed power, out of which 220 GW was in hydropower plants. The energy produced in hydropower facilities was 662.6 TWh from a total of 4,720 TWh electrical energy production in 2011. Moreover, in 2020, new hydropower capacities are going to be developed, with a total of 180 GW installed power and an estimated 708 TWh/year energy production. And in 2011, the installed power of pumped storage stations was about 25GW. In 2020, the data will be 70GW. At the same time, the number of pumps used in China is increasing rapidly. China produces about 29,000,000 pumps with more than 220 series per year. By the end of 2011, the Chinese pumping system has a total of 950 GW installed power. The energy consumed in pumping facilities was 530 TWh in 2011. The pump energy consumption accounted for about 12% of the national electrical energy production. Therefore, there is a large market in the field of hydraulic machinery including water turbines, pump turbines and a variety of pumps in China. There are also many research projects in this field. For example, we have conducted National Key Research Projects on 1000 MW hydraulic turbine, and on the pump turbines with high head, as well as on the large capacity pumps for water supply. Tsinghua University of Beijing is proud to host the 26th IAHR Symposium on Hydraulic Machinery and Systems. Tsinghua University was established in 1911, after the founding of the People's Republic of China. It was molded into a polytechnic institute focusing on engineering in the nationwide restructuring of universities and colleges undertaken in 1952. At present, the university has 14 schools and 56 departments with faculties in science, engineering, humanities, law, medicine, history, philosophy, economics, management, education and art. The University now has over 25 900 students, including 13 100 undergraduates and 12 800 graduate students. As one of China's most renowned universities, Tsinghua has become an important institution for fostering talents and scientific research. The International Association of Hydro-Environment Engineering and Research (IAHR) particularly promotes the advancement and exchange of knowledge through working groups, specialty symposia, congresses, and publications on water resources, river and coastal hydraulics, risk analysis, energy, environment, disaster prevention, and industrial processes. The IAHR Committee on Hydraulic Machinery and Systems deals with the advancement of technology associated with the understanding of steady and unsteady flow characteristics in hydraulic machinery and conduit systems connected to the machinery. The technology elements include the fluid behaviour within machine components, hydro-elastic behaviour of machine components, cavitation and two phase flow in turbines and pumps, hydraulic machine and plant control systems, the use of hydraulic machines to improve water quality, and even considerations to improve fish survival in their passage through hydro plants. The main emphases of the IAHR Committee on Hydraulic Machinery and Systems are to stimulate research and understanding of the technologies associated with hydraulic machinery and to promote interaction between the machine designers, machine users, the academic community, and the community as a whole. Hydraulic machinery is both cost effective and environmentally friendly. The goals of the IAHR Committee on Hydraulic Machinery and Systems are to improve the value of hydraulic machinery to the end user, to the societies, and to improve societies u

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

2012-11-01

85

Concept Evaluation for Hydraulic Yaw System  

DEFF Research Database (Denmark)

The yaw system is the subsystem on a wind turbine which ensures that the rotor plane of the turbine always is facing the wind direction. Studies from [1] show that a soft yaw system may be utilized to dampen the loads in the wind turbine structure. The soft yaw system operates much like a suspension system on a car, leading the loads away from the turbine structure. However, to realize a soft hydraulic yaw system a new design concept must be found. As a part of the development of the new concept a preliminary concept evaluation has been conducted, evaluating seven different hydraulic yaw concepts, ranging from a one-to-one copy of the electrical drive (electrical drives replaced by hydraulic dittos), to floating suspension systems mounted on hydraulic cylinders. Rough calculations of size and consequences of the different systems are presented ending up with the final concept for further investigation. Loads and yaw demands are based on the IEC 61400-1 standard for wind turbine design, and the loads for this examination are extrapolated from the HAWC2 aeroelastic design code. The concepts are based on a 5 MW off-shore turbine.

Stubkier, SØren; Pedersen, Henrik C.

2013-01-01

86

Hydraulics.  

Science.gov (United States)

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

Decker, Robert L.; Kirby, Klane

87

Micromachined hydraulic astable multivibrator  

OpenAIRE

The paper presents a hydraulic astable multivibrator system. The system consists of hydraulic resistors, hydraulic capacitors and hydraulic pressure controlled valves. The system is designed, realised and tested. The measured system behaviour agrees well with the model simulations. The free running frequency of the multivibrator is 0.18 Hz and the output pressure swing is 90% of the supply pressure.

Lammerink, T. S. J.; Tas, N. R.; Berenschot, J. W.; Elwenspoek, M. C.; Fluitman, J. H. J.

1995-01-01

88

Power management for multi-actuator mobile machines with displacement controlled hydraulic actuators  

OpenAIRE

Economic and environmental factors provide the motivation for a continuing trend toward more energy efficient fluid power systems in construction and agricultural machinery. One of the energy-efficient alternatives to today's valve-controlled hydraulic systems is displacement controlled (DC) actuation, in which hydraulic cylinders and motors are controlled directly by variable displacement pumps. ^ The primary contribution of this thesis is a novel method for optimizing the operation of mob...

Williamson, Christopher A.

2010-01-01

89

Reactor Shutdown Mechanism by Top-mounted Hydraulic System  

Energy Technology Data Exchange (ETDEWEB)

There are two types of reactor shutdown mechanisms in HANARO. One is the mechanism driven by a hydraulic system, and the other is driven by a stepping motor. In HANARO, there are four Control Rod Drive Mechanisms (CRDMs) with an individual step motor and four Shutoff (SO) Units with an individual hydraulic system located at the top of reactor pool. The absorber rods in SO units are poised at the top of the core by the hydraulic force during normal operation. The rods of SO units drop by gravity as the first reactor showdown mechanism when a trip is commended by the reactor protection system (RPS). The rods in CRDMs also drop by gravity together as a redundant shutdown mechanism. When a trip is commended by the reactor regulating system (RRS), the absorber rods of CRDM only drop; while the absorber rods of SO units stay at the top of the core by the hydraulic system. The reactivity control mechanisms of in JRTR, one of the new research reactor with plate type fuels, consist of four CRDMs driven by an individual step motor and two second shutdown drive mechanisms (SSDMs) driven by an individual hydraulic system as shown in Fig. 1. The CRDMs act as the first reactor shutdown mechanism and reactor regulating as well. The top-mounted SSDM driven by the hydraulic system for the JRTR is under design in KAERI. The SSDM provides an alternate and independent means of reactor shutdown. The second shutdown rods (SSRs) of the SSDM are poised at the top of the core by the hydraulic system during the normal operation and drop by gravity for the reactor trip. Based on the proven technology of the design, operation and maintenance for HANARO, the SSDM for the JRTR has been optimized by the design improvement from the experience and test. This paper aims for the introduction of the SSDM in the process of the basic design. The major differences of the shutdown mechanisms by the hydraulic system are compared between HANARO and JRTR, and the design features, system, structure and future works are also described

Kim, Sang Haun; Cho, Yeong Garp; Choi, Myoung Hwan; Lee, Jin Haeng; Huh, Hyung; Kim, Jong In [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2012-05-15

90

Control of flexible robots with prismatic joints and hydraulic drives  

International Nuclear Information System (INIS)

The design and control of long-reach, flexible manipulators has been an active research topic for over 20 years. Most of the research to date has focused on single link, fixed length, single plane of vibration test beds. In addition, actuation has been predominantly based upon electromagnetic motors. Ironically, these elements are rarely found in the existing industrial long-reach systems. One example is the Modified Light Duty Utility Arm (MLDUA) designed and built by Spar Aerospace for Oak Ridge National Laboratory (ORNL). This arm operates in larger, underground waste storage tanks located at ORNL. The size and nature of the tanks require that the robot have a reach of approximately 15 ft and a payload capacity of 250 lb. In order to achieve these criteria, each joint is hydraulically actuated. Furthermore, the robot has a prismatic degree-of-freedom to ease deployment. When fully extended, the robot's first natural frequency is 1.76 Hz. Many of the projected tasks, coupled with the robot's flexibility, present an interesting problem. How will many of the existing flexure control algorithms perform on a hydraulic, long-reach manipulator with prismatic links? To minimize cost and risk of testing these algorithms on the MLDUA, the authors have designed a new test bed that contains many of the same elements. This manuscript described a new hydraulically actuated, long-reach manipulator with a flexible prismatic link at ORNL. Focus is directed toward both modeling and control of hydraulic actuators as well as flexible links that have variable natural frequencies

91

Sliding Control with Chattering Elimination for Hydraulic Drives  

DEFF Research Database (Denmark)

This paper presents the development of a sliding mode control scheme with chattering elimination, generally applicable for position tracking control of electro-hydraulic valve-cylinder drives. The proposed control scheme requires only common data sheet information, no knowledge on load characteristics, and employs piston- and valve spool positions- and load- and supply pressure feedback. The main target is to overcome problems with linear controllers deteriorating performance due to the inherent nonlinear nature of such systems. In order to accomplish this task, an integral sliding mode controller is developed for the control derivative based on a reduced order model. Simulation results demonstrate strong robustness when subjected to parameter perturbations and that chattering is eliminated.

Schmidt, Lasse; Andersen, Torben Ole

2012-01-01

92

Logic Threshold Based Energy Control Strategy for Parallel Hydraulic Hybrid Vehicles  

OpenAIRE

To improve the performance of a Parallel Hydraulic Hybrid Vehicle (PHHV), the operation of components in the hydraulic hybrid system of the vehicle should be well coordinated. This study introduces an energy control strategy based on the logic threshold methodology for PHHVs. The energy distribution of the PHHV can be controlled in real-time and the operation modes of the PHHV can be changed dynamically by means of this energy control strategy. A simulation model for the analysis of the whole...

Liu-Tao; Zheng-Jincheng; Wang-Shuwen; Gu-Fangde

2013-01-01

93

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

Science.gov (United States)

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

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

2014-12-01

94

D2O system and oil hydraulic system of fuelling machine  

International Nuclear Information System (INIS)

Two of the most important supporting systems in CANDU fuel handling system--D2O supply and control system and oil hydraulic system are described, focusing on design requirements, major function, system structure and the main work flow of the two systems individually so as to briefly and concisely present the two typical CANDU systems

95

Development And Evaluation Of A Simplified Modeling Approach For Hydraulic Systems  

OpenAIRE

This paper presents how a hydraulic system can be properly modeled for hydraulic balancing, knowledge of flow distribution, coupled simulation, and evaluation of control, etc. It focuses on water-based heating and cooling systems, which generally have high energy efficiency in design but could perform poorly in reality due to the undersensing condition and strong thermal-hydraulic coupling. The study introduces the motivation, presents the simplified modeling methodology, and illustrates the ...

Yu, Yuebin; Loftness, Vivian; Yu, Daihong; Lu, Yan; Hartkopf, Volker

2012-01-01

96

Hydraulic Press with LS System for Modelling of Plastic Working Operations  

OpenAIRE

At first, the paper describes destination of the presented hydraulic press. Next, the substance of load sensing (LS) systems’ operation was introduced, and electro-hydraulic system of this type, installed in laboratory hydraulic press, was described. The control and measurement circuit of the device was also described, and exemplary test results obtained during plastic working operations on soft non-ferrous alloys were presented.

Janusz Pluta

2008-01-01

97

A novel energy recovery system for parallel hybrid hydraulic excavator.  

Science.gov (United States)

Hydraulic excavator energy saving is important to relieve source shortage and protect environment. This paper mainly discusses the energy saving for the hybrid hydraulic excavator. By analyzing the excess energy of three hydraulic cylinders in the conventional hydraulic excavator, a new boom potential energy recovery system is proposed. The mathematical models of the main components including boom cylinder, hydraulic motor, and hydraulic accumulator are built. The natural frequency of the proposed energy recovery system is calculated based on the mathematical models. Meanwhile, the simulation models of the proposed system and a conventional energy recovery system are built by AMESim software. The results show that the proposed system is more effective than the conventional energy saving system. At last, the main components of the proposed energy recovery system including accumulator and hydraulic motor are analyzed for improving the energy recovery efficiency. The measures to improve the energy recovery efficiency of the proposed system are presented. PMID:25405215

Li, Wei; Cao, Baoyu; Zhu, Zhencai; Chen, Guoan

2014-01-01

98

Simulation of Dynamics of System with Hydraulic Lines and Linear Hydraulic Motor with Mass Load  

Directory of Open Access Journals (Sweden)

Full Text Available This paper deals with the numerical simulation of dynamic properties of the system consisting of hydraulic lines and linear hydraulic motor with a mass load. The mathematical model is created using Matlab SimHydraulics software. Oil bulk modulus, elasticity and volumes of pipes and hoses play a significant role in this case. Mathematical models are verified on experimental equipment. Pressure and position responses during sudden stop of a moving cylinder are measured on this equipment.

Vašina M.

2013-04-01

99

Simulation of Dynamics of System with Hydraulic Lines and Linear Hydraulic Motor with Mass Load  

OpenAIRE

This paper deals with the numerical simulation of dynamic properties of the system consisting of hydraulic lines and linear hydraulic motor with a mass load. The mathematical model is created using Matlab SimHydraulics software. Oil bulk modulus, elasticity and volumes of pipes and hoses play a significant role in this case. Mathematical models are verified on experimental equipment. Pressure and position responses during sudden stop of a moving cylinder are measured on this equipment.

Vašina M.; Hružík L.; Bure?ek A.

2013-01-01

100

Hydraulic systems performance of Army engine oils  

Energy Technology Data Exchange (ETDEWEB)

A technical evaluation of qualified military specification lubricants was started by the U.S. Army Belvoir Research and Development Center and was performed at the U.S. Army Fuels and Lubricants Research Laboratory (AFLRL) located at Southwest Research Institute. This work was conducted to determine if such lubricants can be used as hydraulic fluids in Army Commercial Construction Equipment (CCE) and Selected Material Handling Equipment (SMHE). Sixteen military specification lubricants were extensively evaluated using twelve selected tests required by equipment manufacturers and one test developed by AFLRL in conjunction with John Deere. From the data developed, lubricants meeting Army specifications passed 88 percent of all the tests. It appears that the Army engine oils are good potential candidates for use as hydraulic and power transmission lubricants within the Army CCE/SMHE systems. Areas of concern include copper corrosion, wet brake/clutch frictional performance, and final drive gear wear.

Marbach, H.W.; Lestz, S.J.

1984-01-01

101

Use of rule based methods for the control of thermal hydraulic calculations  

International Nuclear Information System (INIS)

In this paper we describe several possibilities for supporting calculations of thermal hydraulic codes like RELAP or TRAC with knowledge bases systems. Special emphasis is put on the intelligent control of the calculation. At first some basic characteristics of knowledge based systems will be presented. Problems in thermal hydraulic calculations on which the use of AI-methods seem to be helpful are discussed next. Subsequently a concept of a knowledge based system for the support of thermal hydraulic calculation is presented. THEX - a prototype of a knowledge based system for monitoring of time rows from thermal hydraulic calculations will be described next. To demonstrate the capabilities of THEX a coupled system including RELAP and techniques available in RSYST was developed (THEXSYST). In the frame of this system results from a RELAP calculation were examined to identify irregularities like undesired peaks or fluctuations

102

Automated Hydraulic System Design and Power Management in Mobile Applications  

DEFF Research Database (Denmark)

Since the first oil crisis in the beginning of the 1970'ties there have been an increasing focus on energy and energy consumption, in the latter years also driven by the climate changes that are taking place. Hydraulic systems have, however, traditionally been characterised by low system efficiency and therefore there is today a shift towards using electric drives as replacement for hydraulic drives. There are, however, a number of different areas, where hydraulic systems offers possibilities that cannot be matched by electric drives, as the hydraulic systems are typically characterised by a much higher force, torque and power density. One of these areas is the mobile hydraulic area, which generally comprise all type of off-highway machinery, such as construction equipment, agricultural equipment etc. But where hydraulic systems earlier was designed with primary focus on cost, dynamic performance and accuracy, energy consumption is becoming an ever more important design parameter. At the same time as the first oil crisis the first hydraulic load sensing (LS) systems also emerged on the market, which, compared to the other systems of the time, offered significant energy saving potentials and which today are found on most medium and high-end mobile hydraulic machinery. Despite the energy saving potentials that these systems posses, compared to the other open-circuit hydraulic system topologies, LS-system may still be subject to very low system efficiencies if not designed correctly. This is typically the case for systems, with highly varying operating conditions and where more work functions (consumers) are operated simultaneously. The low system efficiency is in this regard not necessarily due to low component efficiencies, which often actually have an efficiency comparable to that of electrical machines if operated in the intended and optimal work area, but due to an inappropriate system layout. Most of the power lost in open circuit hydraulic system systems is in this regard in the transmission part, i.e. hosesand fittings, and the valves used to control the system. A large part of the design task is therefore to design the system so these losses may be minimised. The problem with this is that there exist no methods for how to do this, and the design task may generally be a very complex process, which requires substantial prior knowledge and experience. Having designed a systems no methods do either not exist for ensuring that the system designed is actually suited for a given application. Today a change is furthermore happening, where new and more intelligent components, which are electrically controllable, are emerging and more and more sensors are finding their way into the hydraulic machines. This also means that the door is opened for a new range of possibilities with regard to better system utilisation. The latter is both in regard to new functions and facilities, but also with regard to utilising the system in the most energy optimal way, ensuring that all components are working under the most optimal operating conditions. The above in this way constitute the background for the work that is the basis of this report, which deals with how to design and control open-circuit hydraulic systems with multiple consumers to obtain the largest energy utilization, when also considering other design parameters like installation cost, complexity and system performance. The report begins with a presentation and definition of the problem considered and a review of the work that has been made within the area of hydraulic load sensing (LS) systems throughout the last three decades. Through this, the different stability problems that are often encountered in LS-systems are explained along with how they may be avoided. In addition hereto an overview of the work that has been made in relation to electronic load sensing (ELS) systems is presented along with an overview of the other energy efficient system topologies that exist. Finally the first part is completed with an overview of the main contributions from the present work,also d

Pedersen, Henrik Clemmensen

2007-01-01

103

Rubber seals for fluid and hydraulic systems  

CERN Document Server

Rubber Seals for Fluid and Hydraulic Systems is a comprehensive guide to the manufacturing and applications of rubber seals, with essential coverage for industry sectors including aviation, oil drilling and the automotive industry. Fluid leakage costs industry millions of dollars every year. In addition to wasted money, unattended leaks can result in downtime, affect product quality, pollute the environment, and cause injury. Successful sealing involves containment of fluid within a system while excluding the contaminants; the resilience of rubber enables it to be used to achi

Chandrasekaran, Chellappa

2009-01-01

104

Hydraulics.  

Science.gov (United States)

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

Decker, Robert L.

105

Powered orthosis and attachable power-assist device with Hydraulic Bilateral Servo System.  

Science.gov (United States)

This paper discusses the developments and control strategies of exoskeleton-type robot systems for the application of an upper limb powered orthosis and an attachable power-assist device for care-givers. Hydraulic Bilateral Servo System, which consist of a computer controlled motor, parallel connected hydraulic actuators, position sensors, and pressure sensors, are installed in the system to derive the joint motion of the exoskeleton arm. The types of hydraulic component structure and the control strategy are discussed in relation to the design philosophy and target joints motions. PMID:24110321

Ohnishi, Kengo; Saito, Yukio; Oshima, Toru; Higashihara, Takanori

2013-01-01

106

Climate, vegetation, and soil controls on hydraulic redistribution in shallow tree roots  

Science.gov (United States)

Hydraulic redistribution defined as the translocation of soil moisture by plant root systems in response to water potential gradients is a phenomenon widely documented in different climate, vegetation, and soil conditions. Past research has largely focused on hydraulic redistribution in deep tree roots with access to groundwater and/or winter rainfall, while the case of relatively shallow (i.e., ?1-2 m deep) tree roots has remained poorly investigated. In fact, it is not clear how hydraulic redistribution in shallow root zones is affected by climate, vegetation, and soil properties. In this study, we developed a model to investigate the climate, vegetation, and soil controls on the net direction and magnitude of hydraulic redistribution in shallow tree root systems at the growing season to yearly timescale. We used the model to evaluate the effect of hydraulic redistribution on the water stress of trees and grasses. We found that hydraulic lift increases with decreasing rainfall frequency, depth of the rooting zone, root density in the deep soil and tree leaf area index; at the same time for a given rainfall frequency, hydraulic lift increases with increasing average rainstorm depth and soil hydraulic conductivity. We propose that water drainage into deeper soil layers can lead to the emergence of vertical water potential gradients sufficient to explain the occurrence of hydraulic lift in shallow tree roots without invoking the presence of a shallow water table or winter precipitation. We also found that hydraulic descent reduces the water stress of trees and hydraulic lift reduces the water stress of grass with important implications on tree-grass interactions.

Yu, Kailiang; D'Odorico, Paolo

2014-04-01

107

Position and torque tracking: series elastic actuation versus model-based-controlled hydraulic actuation.  

Science.gov (United States)

Robotics used for diagnostic measurements on, e.g. stroke survivors, require actuators that are both stiff and compliant. Stiffness is required for identification purposes, and compliance to compensate for the robots dynamics, so that the subject can move freely while using the robot. A hydraulic actuator can act as a position (stiff) or a torque (compliant) actuator. The drawback of a hydraulic actuator is that it behaves nonlinear. This article examines two methods for controlling a nonlinear hydraulic actuator. The first method that is often applied uses an elastic element (i.e. spring) connected in series with the hydraulic actuator so that the torque can be measured as the deflection of the spring. This torque measurement is used for proportional integral control. The second method of control uses the inverse of the model of the actuator as a linearizing controller. Both methods are compared using simulation results. The controller designed for the series elastic hydraulic actuator is faster to implement, but only shows good performance for the working range for which the controller is designed due to the systems nonlinear behavior. The elastic element is a limiting factor when designing a position controller due to its low torsional stiffness. The model-based controller linearizes the nonlinear system and shows good performance when used for torque and position control. Implementing the model-based controller does require building and validating of the detailed model. PMID:22275654

Otten, Alexander; van Vuuren, Wieke; Stienen, Arno; van Asseldonk, Edwin; Schouten, Alfred; van der Kooij, Herman

2011-01-01

108

Fundamental Research on Hydraulic Systems Driven by Alternating Flow  

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents a new approach to rotary hydraulic systems, and the functional principles of rotary hydraulic systems that can work using alternating flows. Hydraulic transmissions using alternating flows are based on bidirectional displacement of a predefined volume of fluid through the connection pipes between the alternating flow, the pressure energy generator and the motor. The paper also presents some considerations regarding the basic calculation formulas, the design and testing principles for a hydraulic motor driven by alternating flow, and also a three-phase rotary hydraulic motor.

Ioan-Lucian Marcu

2012-01-01

109

Failure Prevention of Hydraulic System Based on Oil Contamination  

Science.gov (United States)

Oil contamination is the major source of failure and wear of hydraulic system components. As per literature survey, approximately 70 % of hydraulic system failures are caused by oil contamination. Hence, to operate the hydraulic system reliably, the hydraulic oil should be of perfect condition. This requires a proper `Contamination Management System' which involves monitoring of various parameters like oil viscosity, oil temperature, contamination level etc. A study has been carried out on vehicle mounted hydraulically operated system used for articulation of heavy article, after making the platform levelled with outrigger cylinders. It is observed that by proper monitoring of contamination level, there is considerably increase in reliability, economy in operation and long service life. This also prevents the frequent failure of hydraulic system.

Singh, M.; Lathkar, G. S.; Basu, S. K.

2012-07-01

110

Hydraulic conductivity of compacted soils controlled by microbial activity.  

Science.gov (United States)

The hydraulic conductivity defines the displacement of liquids inside porous media and affects the fate and transport of contaminants in the environment. In this research the influence of microbial growth and decay inside soil pores on hydraulic conductivity is analysed. Long-term tests performed in silt-bentonite mixtures permeated with distilled water and a nutrients solution demonstrated that hydraulic conductivity of compacted silt-bentonite samples decreases with time of permeation as a bioclogging mechanism develops. The injection of antibiotics and antifungals in the specimens produces a rebound in the hydraulic conductivity associated with the decay of microbial activity. These results show that biomediated reactions can be used to control the flow rate through compacted soil liners. PMID:24956782

Glatstein, Daniel Alejandro; Francisca, Franco Matías

2014-08-01

111

Reactor control system  

International Nuclear Information System (INIS)

The proposal relates to the improvement of a hydraulically controllable system for a nuclear reactor which ensures both safe shutdown in case of a coolant flow failure and easy handling in operation. The reactor contains a number of oblong tubes, some sections of which are located within the reactor core, others above it. Each of these tubes is filled with spherical absorption bodies up to a certain level, thus constituting a hydraulically supported stacked bed. The invention relates to the arrangement of secondary flow paths and the design of the oblong tubes which allow hydraulic control to be exercised as a function of reactor operation. (UWI)

112

Fundamental Research on Hydraulic Systems Driven by Alternating Flow  

OpenAIRE

This paper presents a new approach to rotary hydraulic systems, and the functional principles of rotary hydraulic systems that can work using alternating flows. Hydraulic transmissions using alternating flows are based on bidirectional displacement of a predefined volume of fluid through the connection pipes between the alternating flow, the pressure energy generator and the motor. The paper also presents some considerations regarding the basic calculation formulas, the design and testing pri...

Ioan-Lucian Marcu; Daniel-Vasile Banyai

2012-01-01

113

Hydraulic braking system for loads subjected to impacts and vibrations  

International Nuclear Information System (INIS)

This invention concerns a hydraulic braking system for loads subjected to impacts and vibrations. These double acting telescopic type hydraulic braking systems possess significant drawbacks linked to possibly important hydraulic leaks due to (a) the use of many dynamic seals in such appliances and (b) the effects of the environment of the system on these seals, particularly when employed in nuclear power stations where the seals reach significant temperatures and are subjected to radiation. Under this invention a remedy is suggested to such drawbacks by integrating means to offset automatically the leaks and the accumulation of hydraulic fluid expansions, as well as facilities to show if such leaks have occurred

114

Numerical simulation on a throttle governing system with hydraulic butterfly valves in a marine environment  

Science.gov (United States)

Hydraulic butterfly valves have been widely applied in marine engineering because of their large switching torque, low pressure loss and suitability for large and medium diameter pipelines. Due to control problems resulting from switching angular speeds of the hydraulic butterfly valve, a throttle-governing control mode has been widely adopted, and detailed analysis has been carried out worldwide on the structural principle concerning speed-regulation and the load torque on the shaft while opening or closing a hydraulic butterfly valve. However relevant reports have yet been published on the change law, the error and the influencing factors of the rotational angular velocity of the hydraulic butterfly valve while opening and closing. In this article, research was based on some common specifications of a hydraulic butterfly valve with a symmetrical valve flap existing in a marine environment. The throttle governing system supplied by the accumulator to achieve the switching of the hydraulic control valve was adopted, and the mathematical models of the system were established in the actual conditions while the numerical simulations took place. The simulation results and analysis show that the rotational angular velocity and the error of the hydraulic butterfly valve while switching is influenced greatly by the drainage amount of the accumulator, resulting in pressure loss in the pipeline, the temperature of hydraulic medium and the load of the hydraulic butterfly valve. The simulation results and analysis provide a theoretical basis for the choice of the total capacity of the accumulator and pipeline diameters in a throttle governing system with a hydraulic butterfly valve. It also determines the type and specification of the hydraulic butterfly valve and the design of motion parameters of the transported fluid.

Wan, Hui-Xiong; Fang, Jun; Huang, Hui

2010-12-01

115

The electrohydraulic control of hydraulic turbines. Elektrogidravlicheskoe regulirovanie gidroturbin  

Energy Technology Data Exchange (ETDEWEB)

The book (The Electrohydraulic Control of Hydraulic Turbines), which was published in Prague in 1981, covers the principles of mechanical and electrohydraulic control of hydraulic turbine rotational speeds; the principal function performed by electrohydraulic speed regulators (types PI and PID) are described. Descriptions are provided for the A-ROT regulator (Czechoslovakia) and the regulators manufactured by ASEA, Ateliers des Charmilles, Kvaerner/Nebb, Neyrpic, Siemens, Voith, Woodward and the LMZ Factory and ''Elektropult'' (USSR), together with a description of the electrical circuitry of speed regulators.

Lamac, J.

1981-01-01

116

Proceedings of the Twenty-First Water Reactor Safety Information Meeting: Volume 1, Plenary session; Advanced reactor research; advanced control system technology; advanced instrumentation and control hardware; human factors research; probabilistic risk assessment topics; thermal hydraulics; thermal hydraulic research for advanced passive LWRs  

Energy Technology Data Exchange (ETDEWEB)

This three-volume report contains 90 papers out of the 102 that were presented at the Twenty-First Water Reactor Safety Information Meeting held at the Bethesda Marriott Hotel, Bethesda, Maryland, during the week of October 25--27, 1993. The papers are printed in the order of their presentation in each session and describe progress and results of programs in nuclear safety research conducted in this country and abroad. Foreign participation in the meeting included papers presented by researchers from France, Germany, Japan, Russia, Switzerland, Taiwan, and United Kingdom. The titles of the papers and the names of the authors have been updated and may differ from those that appeared in the final program of the meeting. Individual papers have been cataloged separately. This document, Volume 1 covers the following topics: Advanced Reactor Research; Advanced Instrumentation and Control Hardware; Advanced Control System Technology; Human Factors Research; Probabilistic Risk Assessment Topics; Thermal Hydraulics; and Thermal Hydraulic Research for Advanced Passive Light Water Reactors.

Monteleone, S. [Brookhaven National Lab., Upton, NY (United States)] [comp.

1994-04-01

117

Proceedings of the Twenty-First Water Reactor Safety Information Meeting: Volume 1, Plenary session; Advanced reactor research; advanced control system technology; advanced instrumentation and control hardware; human factors research; probabilistic risk assessment topics; thermal hydraulics; thermal hydraulic research for advanced passive LWRs  

International Nuclear Information System (INIS)

This three-volume report contains 90 papers out of the 102 that were presented at the Twenty-First Water Reactor Safety Information Meeting held at the Bethesda Marriott Hotel, Bethesda, Maryland, during the week of October 25--27, 1993. The papers are printed in the order of their presentation in each session and describe progress and results of programs in nuclear safety research conducted in this country and abroad. Foreign participation in the meeting included papers presented by researchers from France, Germany, Japan, Russia, Switzerland, Taiwan, and United Kingdom. The titles of the papers and the names of the authors have been updated and may differ from those that appeared in the final program of the meeting. Individual papers have been cataloged separately. This document, Volume 1 covers the following topics: Advanced Reactor Research; Advanced Instrumentation and Control Hardware; Advanced Control System Technology; Human Factors Research; Probabilistic Risk Assessment Topics; Thermal Hydraulics; and Thermal Hydraulic Research for Advanced Passive Light Water Reactors

118

Hydraulically actuated hexapod robots design, implementation and control  

CERN Document Server

Legged robots are a promising locomotion system, capable of performing tasks that conventional vehicles cannot. Even more exciting is the fact that this is a rapidly developing field of study for researchers from a variety of disciplines. However, only a few books have been published on the subject of multi-legged robots. The main objective of this book is to describe some of the major control issues concerning walking robots that the authors have faced over the past 10 years. A second objective is to focus especially on very large hydraulically driven hexapod robot locomotion weighing more than 2,000 kg, making this the first specialized book on this topic. The 10 chapters of the book touch on diverse relevant topics such as design aspects, implementation issues, modeling for control, navigation and control, force and impedance control-based walking, fully autonomous walking, walking and working tasks of hexapod robots, and the future of walking robots. The construction machines of the future will very likel...

Nonami, Kenzo; Irawan, Addie; Daud, Mohd Razali

2014-01-01

119

System for Continuous Deaeration of Hydraulic Oil  

Science.gov (United States)

A system for continuous, rapid deaeration of hydraulic oil has been built to replace a prior system that effected deaeration more slowly in a cyclic pressure/ vacuum process. Such systems are needed because (1) hydraulic oil has an affinity for air, typically containing between 10 and 15 volume percent of air and (2) in the original application for which these systems were built, there is a requirement to keep the proportion of dissolved air below 1 volume percent because a greater proportion can lead to pump cavitation and excessive softness in hydraulic-actuator force-versus-displacement characteristics. In addition to overcoming several deficiencies of the prior deaeration system, the present system removes water from the oil. The system (see figure) includes a pump that continuously circulates oil at a rate of 10 gal/min (38 L/min) between an 80-gal (303-L) airless reservoir and a tank containing a vacuum. When the circulation pump is started, oil is pumped, at a pressure of 120 psi (827 kPa), through a venturi tube below the tank with a connection to a stand-pipe in the tank. This action draws oil out of the tank via the standpipe. At the same time, oil is sprayed into the tank in a fine mist, thereby exposing a large amount of oil to the vacuum. When the oil level in the tank falls below the lower of two level switches, a vacuum pump is started, drawing a hard vacuum on the tank through a trap that collects any oil and water entrained in the airflow. When the oil level rises above higher of the two level switches or when the system is shut down, a solenoid valve between the tank and the vacuum pump is closed to prevent suction of oil into the vacuum pump. Critical requirements that the system is designed to satisfy include the following: 1) The circulation pump must have sufficient volume and pressure to operate the venturi tube and spray nozzles. 2) The venturi tube must be sized to empty the tank (except for the oil retained by the standpipe) and maintain a vacuum against the vacuum pump. 3) The tank must be strong enough to withstand atmospheric pressure against the vacuum inside and must have sufficient volume to enable exposure of a sufficiently large amount of sprayed oil to the vacuum. 4) The spray nozzles must be sized to atomize the oil and to ensure that the rate of flow of sprayed oil does not exceed the rate at which the venturi action can empty the tank. 5) The vacuum pump must produce a hard vacuum against the venturi tube and continue to work when it ingests some oil and water. 6) Fittings must be made vacuum tight (by use of O-rings) to prevent leakage of air into the system. The system is fully automatic, and can be allowed to remain in operation with very little monitoring. It is capable of reducing the air content of the oil from 11 to less than 1 volume percent in about 4 hours and to keep the water content below 100 parts per million.

Anderson, Christopher W.

2006-01-01

120

Turbogas control unit using a hydraulic interface; Control de una unidad turbogas usando una interfase hidraulica  

Energy Technology Data Exchange (ETDEWEB)

This paper presents the design and implementation of the control system of the Turbo Generator Unit (TGU) GE 5001, placed in Laguna Chavez power generation facility in Gomez Palacio, Dgo., Mexico. This TGU had been operating with an old control system, back to the 70's. The positioning of the control valves was carried out using a complex electro-hydraulic system. For the modernization of the control system, we use latest PLC technology and a current to pressure converter to communicate the PLC with the hydraulic control valves. The new control system helped us to obtain a best response at the start and generation phases, as well as an increase in the availability of the unit. We show the old and the new control architectures besides plot results obtained at the different operation points. [Spanish] En este articulo se presenta la implementacion y diseno del sistema de control de una Unidad Turbogas (UTG) GE-5001 de la Central Turbogas Laguna Chavez de CFE ubicada en Gomez Palacio, Durango, la cual originalmente era controlada mediante un sistema de control con tecnologia de los anos 70's. El posicionamiento de las valvulas de control se realizaba mediante un sistema electro-hidraulico complejo. Para la modernizacion del sistema de control a uno con tecnologia de punta fue necesario utilizar una interfase hidraulica por medio de un convertidor de corriente/presion (I/P) para el posicionamiento de las valvulas originales. Con la modernizacion se mejoro la respuesta del control asi como el incremento de la disponibilidad de la unidad. Se presentan la arquitectura anterior y actual de sistema de control asi como graficas de los resultados obtenidos en diferentes puntos de operacion de la UTG.

Ramirez Palacios, Ignacio Ramon; Castelo Cuevas, Luis [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)]. E-mail: irrp@iie.org.mx; lcastelo@iie.org.mx; Escarcega Navarrete, Luis [Servi-Control Monterrey S.A. de C.V., Monterrey, Nuevo Leon (Mexico)]. E-mail: lescarcega@servicontrol.com

2010-11-15

121

Structure Parameters Optimization Analysis of Hydraulic Hammer System  

OpenAIRE

In order to improve the impact performance, the structure of hydraulic hammer should be optimized. In this paper, the ranges of eight vital structure parameters of piston and reversing valve system of hydraulic hammer were selected firstly; and then found the best value of different parameters under experiments with the method of computer optimization and the parametric analysis method provided by ADAMS software. These methods worked and the best design values of parameters of hydraulic hamme...

Guoping Yang; Jian Fang

2012-01-01

122

Hydraulic analysis of water supply system Šmartno ob Paki  

OpenAIRE

The subject of the Graduation Project is the hydraulics of the Šmartno ob Paki water supply system. The primary focus is on the analysis of pressure and flow conditions using the appropriate software tools, and the optimisation of the existing situation. The Graduation Project features a theoretical and a practical part. The theoretical part includes all the bases required for hydraulic modelling, and the calculations and analysis of hydraulic conditions, while the practical part involves th...

Stropnik, Petra

2006-01-01

123

Hydraulic power take-off for wave energy systems  

DEFF Research Database (Denmark)

Investigation and laboratory experiments with a hydraulic power conversion system for converting forces from a 2.5m diamter float to extract energy from seawaves. The test rig consists of a hydraulic wave simulator and a hydraulic point absorber. The absorber converts the incomming forces to a continous rotation of an electric generator. The experiments document efficiencies and losses for the conversion process. The experiments are used for verification and update of a computer model.

Christensen, Georg Kronborg

2001-01-01

124

A dynamical system perspective on plant hydraulic failure  

Science.gov (United States)

is governed by leaf water status that depends on the difference between the rates of transpiration and water supply from the soil and through the plant xylem. When transpiration increases compared to water supply, the leaf water potential reaches a more negative equilibrium, leading to water stress. Both high atmospheric vapor pressure deficit and low soil moisture increase the water demand while decreasing the supply due to lowered soil-to-root conductance and xylem cavitation. Therefore, dry conditions may eventually reduce the leaf water potential to the point of collapsing the plant hydraulic system. This "hydraulic failure" is shown to correspond to a fold bifurcation where the environmental parameters (vapor pressure deficit and soil moisture) trigger the loss of a physiologically sustainable equilibrium. Using a minimal plant hydraulic model, coordination among plant hydraulic traits is shown to result in increased resilience to environmental stresses, thereby impeding hydraulic failure unless hydraulic traits deteriorate due to prolonged water shortage or other damages.

Manzoni, Stefano; Katul, Gabriel; Porporato, Amilcare

2014-06-01

125

Trends in Design of Water Hydraulics : Motion Control and Open-Ended Solutions  

DEFF Research Database (Denmark)

The paper presents and discusses a R&D-view on trends in development and best practise in design of both low-pressure and high-pressure tap water hydraulic components and systems for motion control as well as open-ended solutions various industrial applications. The focus is on the advantages using ordinary tap water and the range of application areas are illustrated with examples, in particular within the food processing industry, humidification operations, water mist systems for fire fighting, high water pressure cleaners, water moisturising systems for wood processing, lumber drying process and mobile machines and equipment that operate in environmentally sensitive surroundings. Today’s progress in water hydraulics includes electro-water hydraulic proportional valves and servovalves for design of motion control solutions for machines and robots. The remarkable property is that the components operate with pure water from the tap without additives of any kind. Hence water hydraulics takes the benefit of purewater as fluid being environmentally friendly, easy to clean sanitary design, non-toxic, non-flammable, inexpensive, readily available and easily disposable. The low-pressure tap water hydraulic systems cover up to around 50 bar, and 2-4 kW having a strong potential to compete with pneumatic and electrical solutions in many applications. The high-pressure water hydraulic systems cover typically up to 160 bar pressure from pump and to motors and actuators 140 bar. Recently, dedicated pumps and accessories running with sea-water as fluid are available. A unique solution is to use reverse osmosis to generate drinking water from sea-water, and furthermore for several off-shore applications. Furthermore, tap water hydraulic components of the Nessie® family and examples of measured performance characteristics are presented and the trends in industrial applications and need for future are discussed.

Conrad, Finn Technical University of Denmark,

2005-01-01

126

46 CFR 128.240 - Hydraulic or pneumatic power and control-materials and pressure design.  

Science.gov (United States)

...2010-10-01 2010-10-01 false Hydraulic or pneumatic power and control-materials...Materials and Pressure Design § 128.240 Hydraulic or pneumatic power and control—materials...flanges, and standard valves) for hydraulic or pneumatic power and control...

2010-10-01

127

Output Feedback Control of Electro-Hydraulic Cylinder Drives using the Twisting Algorithm  

DEFF Research Database (Denmark)

This paper discusses the utilization of the so-called twisting algorithm when applied in output feedback position control schemes for electro-hydraulic cylinder drives. The twisting controller was the first second order sliding controller ever introduced, and can structure-wise be considered a straight forward extension of the simplest first order sliding controller, that is, a relay controller. Such a controller may be implemented without the knowledge of system time constants etc., as opposed to the surface based first order sliding controllers which has been presented in numerous contributions in literature. This paper considers the twisting algorithm when applied directly for output feedback control, and with the design based on a reduced order model representation of an arbitrary valve driven hydraulic cylinder drive. The consequence of implementing such a controller with the well-known saturation-, or boundary layer method is discussed, and the control operation inside- and outside the boundary layer region is considered. Furthermore, the global stability of such a controller is discussed, with emphasis on possible local instability modes. Results demonstrate that the proposed output feedback controller may be successfully applied to hydraulic valve driven cylinder drives, with performance being on the level with a conventional surface based first order sliding mode controller.

Schmidt, Lasse; Andersen, Torben Ole

2014-01-01

128

Hydraulic Soft Yaw System for Multi MW Wind Turbines  

DEFF Research Database (Denmark)

Horizontal axis wind turbines utilize a yaw system to keep the rotor plane of the wind turbine perpendicular to the main wind direction. If the wind direction changes, the wind turbine follows the direction change by yawing. If the wind turbine does not yaw, there will be a reduction in produced energy and an increase in the loading of the wind turbine structure and components. This dissertation examines the hypothesis that there are advantages of basing a yaw system on hydraulic components instead of normal electrical components. This is done through a state of the art analysis followed by a systematic concept generation and analysis of different concepts, where a single concept is chosen for further analysis. A preliminary analysis, based on simulations of the NREL 5 MW turbine modified to include a soft yaw system, show that the soft yaw concept chosen leads to signicant load reductions in the wind turbine yaw system along with minor reductions in the blades and main shaft. Optimization of the damping and stiffness of the hydraulic soft yaw system have been conducted and an optimum found for load reduction. Linear control algorithms for control of damping pressure peaks have been developed and tested in simulations with success. To verify the results of the new hydraulic soft yaw concept a novel friction model for including coulomb in the yaw system is developed and implemented in the FAST aeroelastic code from NREL in order to include friction phenomena. A cosimulation interface between the full turbine code in FAST, and the mathematical model of the hydraulic yaw system in Matlab/Simulink and Amesim is developed in order to analyze a full scale model of the hydraulic yaw system in combination with the implemented friction model for the yaw system. These results are also promising regarding load reduction and operating conditions for the hydraulic components. The results for simulations of a normal stiff yaw system, a yaw system with friction plate yaw bearing and a yaw system with a roller type bearing with low friction are analyzed and so is the loading of the systems. Based on the results a full scale test rig is designed and constructed for workshop testing and model validation. The test rig is designed so that it is possible to apply loads directly from the FAST simulations and hence get realistic results. Results from the test rig are presented and analyzed and the hydraulic model validated for further testing in the co-simulation environment. All test are performed according to the standard IEC 61400-1; Wind turbines- Part 1: Design requirements, why the load cases may be recognized from this standard. The model is further used for testing of the developed self yaw system, which enables the turbine to yaw without any energy input, but simply by utilizing the loading from the wind to turn in the right direction. Further the concept of the over-load protection system is analyzed and found very efficient for lowering the ultimate loading on the wind turbine structure. The influence on theenergy capture is analyzed and by the present simulation standards it is hard to quantify the inuence of the soft yaw system, however, the energy capture is increased for situations including a yaw error. The research documented in this dissertation has contributed with a concept evaluation of nine concepts for hydraulic yaw systems and shown that the loading of the turbine structure may be damped if the yaw system is allowed to deflect under loading. An extensions of the open source wind turbine code FAST of a state of the art wind turbine including the yaw degree of freedom and friction in the yaw bearing has furthermore been made public available. A passive self yaw system has been designed, analyzed and patented for off grid operation and operation above rated wind speed. The positive effects of a well defined over-load protection system has also been analyzed and documented. The conclusion of the research presented in this dissertation is a product ready to be tailored to fit OEM prototype turbines for field tests.

Stubkier, SØren

2013-01-01

129

Structure Parameters Optimization Analysis of Hydraulic Hammer System  

Directory of Open Access Journals (Sweden)

Full Text Available In order to improve the impact performance, the structure of hydraulic hammer should be optimized. In this paper, the ranges of eight vital structure parameters of piston and reversing valve system of hydraulic hammer were selected firstly; and then found the best value of different parameters under experiments with the method of computer optimization and the parametric analysis method provided by ADAMS software. These methods worked and the best design values of parameters of hydraulic hammer were obtained. At last, the optimal impact energy of virtual prototype of hydraulic breaking hammer was calculated and compared with the original impact performance. The results reveal that impact performance of hydraulic hammer has been improved significantly.

Guoping Yang

2012-11-01

130

Design of a Hydraulic Motor System Driven by Compressed Air  

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents the design of a highly efficient pneumatic motor system. The air engine is currently the most generally used device to convert potential energy of compressed air into mechanical energy. However, the efficiency of the air engines is too low to provide sufficient operating range for the vehicle. In this study, the energy contained in compressed air/pressurized hydraulic oil is transformed by a hydraulic motor to mechanical energy to enhance the efficiency of using air power. To evaluate the theoretical efficiency, the principle of balance of energy is applied. The theoretical efficiency of converting air into hydraulic energy is found to be a function of pressure; thus, the maximum converting efficiency can be determined. To confirm the theoretical evaluation, a prototype of the pneumatic hydraulic system is built. The experiment verifies that the theoretical evaluation of the system efficiency is reasonable, and that the layout of the system is determined by the results of theoretical evaluation.

Jyun-Jhe Yu

2013-06-01

131

Chaos in a Hydraulic Control Valve  

Science.gov (United States)

In this paper we have studied the instability and chaos occurring in a pilot-type poppet valve circuit. The system consists of a poppet valve, an upstream plenum chamber, a supply pipeline and an orifice inserted between the pelnum and the pipeline. Although the poppet valve rests on the seat stably for a supply pressure lower than the cracking pressure, the circuit becomes unstable for an initial disturbance beyond a critical value and develops a self-excited vibration. In this unstable region, chaotic vibration appears at the period-doubling bifurcation. We have investigated the stability of the circuit and the chaotic phenomenon numerically, and elucidated it by power spectra, a bifurcation diagram and Lyapunov exponent calculations, showing that the phenomenon follows the Feigenbaum route to chaos.Copyright 1997 Academic Press Limited

Hayashi, S.; Hayase, T.; Kurahashi, T.

1997-08-01

132

Investigation of Self Yaw and its Potential using a Hydraulic Soft Yaw System for 5 MW Wind Turbine  

DEFF Research Database (Denmark)

The focus of the current paper is on a hydraulic soft yaw system, designed to reduce the loading of the turbine structure, by absorbing wind guest via the hydraulic system, but which also enables the system to be used as a self-aligning yaw system. The system is analyzed with basis in the NREL 5-MW turbine, modeled in FAST, in which a new robust method for implementing Coulomb friction is utilized. Based on this model and a model of the hydraulic system, the influence of friction and wind speed is investigated in relation to the possibility to use the system as a self-aligning yaw system. Similarly the behavior of the hydraulic system is analyzed and it is concluded that the hydraulic yaw system allows selfyaw under normal operating conditions for the turbine. Self-yaw control is possible in wind speeds above 12 m/s when yaw friction is kept below 1 MNm.

Stubkier, SØren; Pedersen, Henrik C.

2013-01-01

133

Hydraulically driven control rod concept for integral reactors: fluid dynamic simulation and preliminary test  

International Nuclear Information System (INIS)

The paper deals with the preliminary study of the Hydraulically Driven Control Rod concept, tailored for PWR control rods (spider type) with hydraulic drive mechanism completely immersed in the primary water. A specific solution suitable for advanced versions of the IRIS integral reactor is under investigation. The configuration of the Hydraulic Control Rod device, made up by an external movable piston and an internal fixed cylinder, is described. After a brief description of the whole control system, particular attention is devoted to the Control Rod characterization via Computational Fluid Dynamics (CFD) analysis. The investigation of the system behavior, including dynamic equilibrium and stability properties, has been carried out. Finally, preliminary tests were performed in a low pressure, low temperature, reduced length experimental facility. The results are compared with the dynamic control model and CFD simulation model, showing good agreement between simulations and experimental data. During these preliminary tests, the control system performs correctly, allowing stable dynamic equilibrium positions for the Control Rod and stable behavior during withdrawal and insertion steps. (author)

134

Hydraulically supported absorber balls shutdown system for inherently safe LMFBR's  

International Nuclear Information System (INIS)

A diverse, inherently-actuated control system would be very valuable for Advanced LMFBR's since its use may preclude the consideration of a ''hypothetical core disruptive accident'' as a design basis. An Inherent Shutdown System (ISS) which uses a number of subassemblies, each containing a column of hydraulically supported tantalum balls, is being studied. This system appears to be capable of successfully protecting the public (and the reactor) from low-probability high-consequence events, such as a loss-of-flow or transient-over-power incident with failure of the normal control system (or systems) to scram. A number of columns of small (about 1/4 in. OD) tantalum balls are held above the active core region of a reactor by the reactor coolant flow. These columns automatically fall into the core and shut the reactor down if the coolant flow of the reactor is interrupted by a loss-of-flow event. A thermally-actuated valve within each ISS subassembly enables this system to shut down the reactor during a transient-over-power event. This control system is extremely diverse since it can operate in a severely distorted core and is independent of top shield rotation. Also, it is basically very simple and should be extremely reliable after it is developed

135

An approach for second order control with finite time convergence for electro-hydraulic drives  

DEFF Research Database (Denmark)

Being a second order sliding algorithm, the super twisting algorithm is highly attractive for application in control of hydraulic drives and mechanical systems in general, as it utilizes only the control error while driving the control error as well as its derivative to zero for properly chosen algorithm parameters. However a discontinuous term internally in the control structure may excite pressures of transmission lines in hydraulic drives as the control structure strives to maintain the control error and its derivative equal to zero. In this paper a modified version of a controller based on the super twisting algorithm is proposed, with the focus of eliminating the discontinuous term in order to achieve a more smooth control operation. The convergence properties of the proposed controller are analyzed via a conservative phase plane analysis. Furthermore, homogeneity considerations imply finite time convergence of states to the origin under certain model assumptions. Results demonstrate the smooth control operation compared to the direct super twisting control approach while maintaining robustness properties in relation to position tracking of a hydraulic drive, under parameter perturbations, uncertainties and un-modeled dynamics.

Schmidt, Lasse; Andersen, Torben Ole

2013-01-01

136

A Model Predictive Control Approach for Fuel Economy Improvement of a Series Hydraulic Hybrid Vehicle  

Directory of Open Access Journals (Sweden)

Full Text Available This study applied a model predictive control (MPC framework to solve the cruising control problem of a series hydraulic hybrid vehicle (SHHV. The controller not only regulates vehicle velocity, but also engine torque, engine speed, and accumulator pressure to their corresponding reference values. At each time step, a quadratic programming problem is solved within a predictive horizon to obtain the optimal control inputs. The objective is to minimize the output error. This approach ensures that the components operate at high efficiency thereby improving the total efficiency of the system. The proposed SHHV control system was evaluated under urban and highway driving conditions. By handling constraints and input-output interactions, the MPC-based control system ensures that the system operates safely and efficiently. The fuel economy of the proposed control scheme shows a noticeable improvement in comparison with the PID-based system, in which three Proportional-Integral-Derivative (PID controllers are used for cruising control.

Tri-Vien Vu

2014-10-01

137

Combustion waves in hydraulically resisted systems.  

Science.gov (United States)

The effects of hydraulic resistance on the burning of confined/obstacle-laden gaseous and gas-permeable solid explosives are discussed on the basis of recent research. Hydraulic resistance is found to induce a new powerful mechanism for the reaction spread (diffusion of pressure) allowing for both fast subsonic as well as supersonic propagation. Hydraulic resistance appears to be of relevance also for the multiplicity of detonation regimes as well as for the transitions from slow conductive to fast convective, choked or detonative burning. A quasi-one-dimensional Fanno-type model for premixed gas combustion in an obstructed channel open at the ignition end is discussed. It is shown that, similar to the closed-end case studied earlier, the hydraulic resistance causes a gradual precompression and preheating of the unburned gas adjacent to the advancing deflagration, which leads (after an extended induction period) to a localized autoignition that triggers an abrupt transition from deflagrative to detonative combustion. In line with the experimental observations, the ignition at the open end greatly encumbers the transition (compared with the closed-end case), and the deflagration practically does not accelerate up to the very transition point. Shchelkin's effect, that ignition at a small distance from the closed end of a tube facilitates the transition, is described. PMID:22213662

Brailovsky, I; Kagan, L; Sivashinsky, G

2012-02-13

138

State of Art of the CAREM-25 Hydraulic Control Rod Drives Feasibility Analysis  

International Nuclear Information System (INIS)

The proposed design adopted for the control rod drives for the CAREM reactor is based on a hydraulic system.As any innovative device, the design process requires to obtain experimental evidence to identify the most important control parameters and to set their relationship with other design parameters, in order to guarantee its feasibility as a previous step to the design qualification tests at the working conditions at the reactor.This paper features a global evaluation of the analysis performed and experimental results obtained in a low pressure loop, design improvements, limiting phenomena identified and corrective actions analyzed or proposed.The evaluation is based on a repetitivity, sensitivity and scalability study of the control parameters and test conditions, as well as the dynamic response between rod drive and the hydraulic system and features related with the mechanical design.Obtained results show that present system has an adequate response compatible with functional and manufacturing requirements

139

Energy efficient hydraulic systems for large engines  

Energy Technology Data Exchange (ETDEWEB)

Hydrostatic power offers considerable advantages in terms of transmission flexibility, controllability and power density. There are many potential uses for hydrostatic power on large engines, of which several are standard on low speed two-strokes. Bosch Rexroth and a partner company have developed hydrostatic systems for converting surplus energy in engine exhaust gases into interesting fuel saving options, including power-take-in at the crankshaft and driving auxiliary systems. (orig.)

Fischer, Steffen [Bosch Rexroth AG, Lohr am Main (Germany)

2013-10-15

140

European developments in thermal-hydraulics for innovative nuclear systems  

International Nuclear Information System (INIS)

Thermal-hydraulics is recognized as a key scientific subject in the development of different innovative nuclear reactor systems. In Europe, thermal-hydraulic issues for innovative reactors are the subject of the Thermal-Hydraulics of Innovative Nuclear Systems project (THINS) which is sponsored by the European Commission and runs from 2010 until 2014. This paper will describe the status of the on-going activities in this project. The project addresses the main identified thermal hydraulics issues for innovative nuclear systems taking into account existing experimental data and producing new experimental data where needed. These issues are: -) advanced reactor core thermal-hydraulics, -) single phase mixed convection, -) single phase turbulence, -) multiphase flow, and -) numerical code coupling and qualification. The overall objectives of the THINS project are the development and validation of new physical models, improvement and qualification of numerical engineering tools and their application to innovative nuclear systems. A specific part of the project is devoted to education and training in order to dispatch the state-of- the-art scientific knowledge gained within the project which will be attractive to students and (young) researchers in the field of thermal-hydraulics internationally

141

Contaminant monitoring of hydraulic systems. The need for reliable data  

Energy Technology Data Exchange (ETDEWEB)

The need for both reliable operation of hydraulic and lubrication systems and long component lives has focused users to the benefits of controlling the contamination in the hydraulic fluid. Maximum operating (target) levels are being implemented as part of a condition based maintenance regime. If these are exceeded, maintenance effort is directed to correcting the rise in consummation level, and so make optimum use of resources as maintenance effort is only affected when it is necessary to do so. Fundamental to ibis aspect of condition based monitoring is the provision of accurate and reliable data in the shortest possible time. This way, corrective actions can be implemented immediately so minimising the damage to components. On-line monitoring devices are a way of achieving this and are seeing increased use, but some are affected by the condition of the fluid. Hence, there is a potential for giving incorrect data which will waste time and effort by initiating unnecessary corrective actions. A more disturbing aspect is the effect on the user of continual errors. The most likely effect would be a loss of confidence in the technique or even complete rejection of it and hence the potential benefits will be lost. This presentation explains how contaminant monitoring techniques are applied to ensure that the potential benefits of operating with clean fluids is realised. It examines the sources of error and shows how the user can interrogate the data and satisfy himself of its authenticity. (orig.) 14 refs.

Day, M.J. [Pall Europe Ltd., Portsmouth (United Kingdom)] Rinkinen, J. [Tampere University of Technology, Tampere (Finland)

1997-12-31

142

Design of a Hydraulic Motor System Driven by Compressed Air  

OpenAIRE

This paper presents the design of a highly efficient pneumatic motor system. The air engine is currently the most generally used device to convert potential energy of compressed air into mechanical energy. However, the efficiency of the air engines is too low to provide sufficient operating range for the vehicle. In this study, the energy contained in compressed air/pressurized hydraulic oil is transformed by a hydraulic motor to mechanical energy to enhance the efficiency of using air power....

Jyun-Jhe Yu; Dein Shaw; Cheng Chieh

2013-01-01

143

Development of realistic thermal-hydraulic system analysis codes ; development of thermal hydraulic test requirements for multidimensional flow modeling  

Energy Technology Data Exchange (ETDEWEB)

This study is concerned with developing a multidimensional flow model required for the system analysis code MARS to more mechanistically simulate a variety of thermal hydraulic phenomena in the nuclear stem supply system. The capability of the MARS code as a thermal hydraulic analysis tool for optimized system design can be expanded by improving the current calculational methods and adding new models. In this study the relevant literature was surveyed on the multidimensional flow models that may potentially be applied to the multidimensional analysis code. Research items were critically reviewed and suggested to better predict the multidimensional thermal hydraulic behavior and to identify test requirements. A small-scale preliminary test was performed in the downcomer formed by two vertical plates to analyze multidimensional flow pattern in a simple geometry. The experimental result may be applied to the code for analysis of the fluid impingement to the reactor downcomer wall. Also, data were collected to find out the controlling parameters for the one-dimensional and multidimensional flow behavior. 22 refs., 40 figs., 7 tabs. (Author)

Suh, Kune Yull; Yoon, Sang Hyuk; Noh, Sang Woo; Lee, Il Suk [Seoul National University, Seoul (Korea)

2002-03-01

144

Second Order Sliding Mode Control with Prescribed Convergence Law for Electro-Hydraulic Drives  

DEFF Research Database (Denmark)

This paper discusses the application of second order sliding modes for position tracking control of electro-hydraulic valve-cylinder drives (VCD’s). The target is to introduce increased tracking- and transient performance compared to conventional linear approaches, without extending the number of tuning parameters. The proposed controller utilizes basic component knowledge commonly available from data sheets, as well as pressure-, valve position-, piston position- and velocity measurements. Results demonstrate improved position tracking- and transient performance, compared to a linear control approach, and that control chattering is eliminated without introducing a boundary layer, normally seen in first order sliding mode controlled systems.

Schmidt, Lasse; Andersen, Torben Ole

2013-01-01

145

Study on the Energy-Regeneration-based Velocity Control of the Hydraulic-Hybrid Vehicle  

OpenAIRE

This paper simplifies the energy regenerationbased vehicle velocity system of the hydraulichybrid businto a process in which the extension rod of the hydraulic cylinder drives the secondary-element variable delivery pump/motor to change its displacement. This process enables braking of the vehicle and also allows recovery of energy. The stability, energy efficiency and other characteristics of the system are studied based on analysis of mathematical models of the vehicle velocity control. The...

Song, Yunpu

2012-01-01

146

Kinetic resistance of hydraulic cylinder for control rod hydraulic drive mechanism in step-down motion process  

International Nuclear Information System (INIS)

Hydraulic cylinder is the main component of the control rod hydraulic drive mechanism (CRHDM). Step-up and step-down motions are the functions of hydraulic cylinder. The kinetic resistance of hydraulic cylinder during step-down motion is the key parameter in the hydraulic cylinder structure design and step-down analysis. Theoretical analysis of hydraulic cylinder step-down process was carried out to establish the dynamic model of the process. The step-down velocity and acceleration were obtained by combining the step-down dynamic model and the results of the CRHDM single cylinder experiment, which lead to two sets of step-down kinetic resistance models. Comparison of these two models and their calculation results shows that, under the experimental conditions, the displacement curves inferred from these models agree with the experimental data. And in the model based on step-down acceleration the kinetic resistance is the function of inner cylinder's velocity and the hydraulic pressure inside the cylinder, the relationship of the coefficients in the model to the loadings is easy to obtain, so the kinetic resistance model based on step-down acceleration is more applicable to engineering use and extension. (authors)

147

Application of multi-sensor information fusion technology on fault diagnosis of hydraulic system  

International Nuclear Information System (INIS)

The structural layers and methods of multi-sensor information fusion technology are analysed, and its application in fault diagnosis of hydraulic system is discussed. Aiming at hydraulic system, a model of hydraulic fault diagnosis system based on multi-sensor information fusion technology is presented. Choosing and implementing the method of information fusion reasonably, the model can fuse and calculate various fault characteristic parameters in hydraulic system effectively and provide more valuable result for fault diagnosis of hydraulic system.

148

Study on visual modeling and simulation platform of hydraulic system based on bond graph  

Science.gov (United States)

According to the tendency that hydraulic drive and control systems become more complex and require higher dynamic performance, an advanced visual modeling and simulation methodology for hydraulic systems was proposed. A bond graph was introduced as a modeling tool that provides an intuitive and unified approach to the modeling of multi-domain and nonlinear hydraulic systems. An open-ended hydraulic module library was established by uniting the theories of bond graph and modularization. The Hydraulic Visual Modeling and Simulation Platform (HVMSP) was compiled with the object-oriented VISUAL BASIC language. With the platform, the MATLAB language, which is well recognized as a powerful tool for matrix computation and dynamic simulation, can be background activated. After a series of relevant background computation process, the bond graph model can be automatically translated into a mathematical model, and the SIMULINK toolbox of MATLAB will simulate the mathematical model of hydraulic system. In the end, the feasibility and efficiency of the method are verified with a given practical example.

Xiao, Yuejun; Zhu, Jiangong; Zhang, Dehu

2005-12-01

149

Hydraulic External Pre-Isolator System for LIGO  

CERN Document Server

The Hydraulic External Pre-Isolator (HEPI) is the first 6 degrees of freedom active seismic isolation system implemented at the Laser Interferometer Gravitational Wave Observatory (LIGO). Implementation was first completed at the LIGO Livingston Observatory (LLO) prior to LIGO's 5th science run, successfully cutting down the disturbance seen by LLO's suspended optics in the two most prominent seismic disturbance bands, the microseism (0.1-0.3Hz) and the anthropogenic (1-3Hz) bands, by a factor of a few to tens. The improvement in seismic isolation contributed directly to LLO's much improved duty cycle of 66.7% and LIGO's triple coincident duty cycle of 53%. We report the design, control scheme, and isolation performance of HEPI at LLO in this paper. Aided with this success, funding for incorporating HEPI into the LIGO Hanford Observatory was approved and installation is currently underway.

Wen, S; Mason, K; Giaime, J; Abbott, R; Kern, J; O'Reilly, B; Bork, R; Hammond, M; Hardham, C; Lantz, B; Hua, W; Coyne, D; Traylor, G; Overmier, H; Evans, T; Hanson, J; Spjeld, O; Macinnis, M; Mailand, K; Sellers, D; Carter, K; Sarin, P

2013-01-01

150

ATHENA: a thermal hydraulic simulation code for space reactor system design and analysis  

International Nuclear Information System (INIS)

This paper describes the general capabilities available in the Advanced Thermal-Hydraulic Energy Network Analyzer (ATHENA) code and emphasizes those features particularly applicable to space reactor system analysis. This code has been developed as a part of the Department of Energy (DOE) Fusion Safety program for use in safety analysis of magnetic fusion systems. ATHENA is designed for transient thermal hydraulic analysis of systems which contain one or several fluid circuits with thermal interactions. The fluid systems can be either one or two phase and can contain a variety of component types such as pumps, valves, heat pipes, separators, and control systems. The ATHENA code has wide applicability for transient thermal hydraulic analysis and is currently being used for transient system simulation of candidate space reactor concepts

151

Evidence for internal hydraulic control in the northern Øresund  

DEFF Research Database (Denmark)

New observations of mainly flow velocity, salinity, and temperature are used to show and discuss some of the physical conditions in Oslashresund, the strait between Denmark and Sweden, one of three connections between the brackish Baltic Sea and the saline North Sea. The main geometric features are a contraction in the northern Oslashresund and the shallow Drogden sill at the entrance to the Baltic. The observations show that the two-layer flows through the contraction are often hydraulically controlled. The observations also reveal details of the transition from subcritical to supercritical flow. In terms of the composite Froude number, on the basis of local flow parameters these details are that the flow may be subcritical as well as supercritical in different areas of some cross section. Existing theories on rotating hydraulics are unable to account for these circumstances, which are due to the strong influence of the Earth's rotation and the curvature of the streamlines. In the present study it is not attempted to explain these conditions, but the probable effects of rotation and curvature on the controlled flow rate are discussed briefly. Also, the possible effects of hydraulic control on the exchange of the Baltic are discussed. It is argued that the stratification in the Kattegat, the sea to the north, is more important than the presence of the Drogden sill for the amount of high saline water to enter the Baltic through Oslashresund. This result is supported by observations of the stratification in Oslashresund and the flow at the sill. The observations show that the interface in Oslashresund rises significantly during flow to the Baltic and that the transport of saline water into the Baltic is closely connected to the shallowness of the interface in Oslashresund

Nielsen, Morten Holtegaard

2001-01-01

152

Hydraulic characterization of a small groundwater flow system in fractured monzonitic gneiss  

International Nuclear Information System (INIS)

The hydraulic characteristics of a small groundwater flow system active in a 200-m by 150-m by 50-m deep block of fractured monzonitic gneiss located at Chalk River, Ontario have been determined from surface and bore-hole investigations. Surface investigations including air photo lineament analysis, ground and airborne geophysics and fracture mapping were used to define the local and regional fracture system, locate the study site and direct the exploratory drilling program. Subsurface investigations were completed in 17 boreholes and included fracture logging, systematic straddle-packer injection testing, hydraulic interference testing and long-term hydraulic head monitoring. The interference tests and monitoring were conducted in 90 packer-isolated test intervals created by installation of multiple-packer casings in each borehole. Hydraulic interference tests provided detailed information on the equivalent single-fracture aperture and storativity of four major (? 50-m extent) fracture zones and the vertical hydraulic diffusivity of the rock mass of the study site. Fracture logs and injection test data were combined to generate a tensoral representation of hydraulic conductivity for each test interval. The results of the detailed investigations are presented and interpreted to provide a complete three-dimensional description of the groundwater flow system. A gravity-controlled flow system occurs at the Chalk River study site. Groundwater flow in the rock is primarily vertical to a low-hydraulic head, fracture zone at 33 to 50 m depth with a horizontal component of flow determined by surface topography. An impermeable diabase dyke and three additional high-permeability fracture zones are important hydrogeologic features influencing flow at the study site. The results of the investigations also show that characterization of the geometric and hydraulic properties of large structural discontinuities is essential in understanding the flow of fluids in fractured rocks

153

Teaching Thermal Hydraulics & Numerical Methods: An Introductory Control Volume Primer  

Energy Technology Data Exchange (ETDEWEB)

A graduate level course for Thermal Hydraulics (T/H) was taught through Idaho State University in the spring of 2004. A numerical approach was taken for the content of this course since the students were employed at the Idaho National Laboratory and had been users of T/H codes. The majority of the students had expressed an interest in learning about the Courant Limit, mass error, semi-implicit and implicit numerical integration schemes in the context of a computer code. Since no introductory text was found the author developed notes taught from his own research and courses taught for Westinghouse on the subject. The course started with a primer on control volume methods and the construction of a Homogeneous Equilibrium Model (HEM) (T/H) code. The primer was valuable for giving the students the basics behind such codes and their evolution to more complex codes for Thermal Hydraulics and Computational Fluid Dynamics (CFD). The course covered additional material including the Finite Element Method and non-equilibrium (T/H). The control volume primer and the construction of a three-equation (mass, momentum and energy) HEM code are the subject of this paper . The Fortran version of the code covered in this paper is elementary compared to its descendants. The steam tables used are less accurate than the available commercial version written in C Coupled to a Graphical User Interface (GUI). The Fortran version and input files can be downloaded at www.microfusionlab.com.

D. S. Lucas

2004-10-01

154

Accumulator isolator prevents malfunctioning of faulty hydraulic system  

Science.gov (United States)

Special isolator valve prevents malfunction of a closed hydraulic system by converting the initial accumulator-reservoir to a reservoir function only when the system loses oil, or gaseous nitrogen precharge, or has a jammed piston. This permits near-normal operation until the defect is corrected.

Walsh, G. D.

1967-01-01

155

Study on the Energy-Regeneration-based Velocity Control of the Hydraulic-Hybrid Vehicle  

Directory of Open Access Journals (Sweden)

Full Text Available This paper simplifies the energy regenerationbased vehicle velocity system of the hydraulichybrid businto a process in which the extension rod of the hydraulic cylinder drives the secondary-element variable delivery pump/motor to change its displacement. This process enables braking of the vehicle and also allows recovery of energy. The stability, energy efficiency and other characteristics of the system are studied based on analysis of mathematical models of the vehicle velocity control. The relevant controller is designed to study effects of the controller on system characteristics. The vehicle velocity control module of the energy regeneration system is stable and able to recovery the inertia energy generated in vehicle braking. After the controller intended to improve response speed is added, system response becomes quicker but energy recovery rate declines.

SONG Yunpu

2012-11-01

156

WATER ENERGY IN HYDROAMELIORATIVE SYSTEMS USING THE HYDRAULIC TRANSFORMER TYPE A. BARGLAZAN AND THE HYDRAULIC HAMMER (HYDRAULIC PUMP)  

OpenAIRE

This paper presents two examples of exploitation of water energy that can be used in the irrigation field. First of theseexamples is the hydraulic transformer type A. Barglazan used for irrigation, pumped water is taken directly from theriver’s well, using a hydraulic pump which simultaneously carried out a double transformation in this way: hydraulicenergy into mechanic energy and mechanical energy into hydraulic energy. Technology preparation and devices designwas done in record time, see...

Teodor Eugen Man; Laura Constantinescu; Dima Attila Blenesi

2010-01-01

157

Test Rig Design and Presentation for a Hydraulic Yaw System  

DEFF Research Database (Denmark)

The design and development of a hydraulic yaw system for multi MWturbines is presented and the concept explained. As part of the development of the new concept a full scale test rig for a 5 MW wind turbine has been designed and constructed. The test rig is presented along with its unique design features. The design process is outlined to give insight in the design criteria driving the design. Loads and yaw demands are based on the IEC 61400-1 standard for wind turbine design, and the loads for this examination are extrapolated from the FAST aero elastic design software. The concepts are based on a 5 MW offshore turbine. After the system presentation, measurement results are presented to verify the behavior of the system. The loads to the system are applied by torque controlled electrical servo drives, which can add a load of up to 3 MNm to the system. This gives an exact picture of the system dynamics under real conditions. The behavior of the system is analyzed with regard to 20 years of operation. This is for example done by applying loads from different design load cases, e.g. normal turbulence, extreme turbulence and different fault scenarios on the turbine. The paper first presents an introduction with the current state of the art and problem description, followed by a system description, where the system is designed and dimensioned. Based on the design, results from the test rig are presented and analyzed. Finally a conclusion summing up the design, model and test results is given.

Stubkier, SØren; Pedersen, Henrik C.

2013-01-01

158

Control Strategies for a simple Point-Absorber Connected to a Hydraulic Power Take-off  

Energy Technology Data Exchange (ETDEWEB)

Among the various types of wave energy converters currently being developed, heaving point absorbers are one of the simplest and most promising concepts, possibly due to their ease of deployment and integration in larger arrays structures. A typical efficient energy conversion system for point absorbers is based on hydraulic power take-off (PTO) systems, consisting in a double-acting cylinder and two or more accumulators, reserving fluid at different pressures and linked between them by a hydraulic motor connected to an electric generator. For the purpose of control and modulation of the power output the hydraulic circuit might include a certain number of valves that can set the pressure levels within the accumulators. This paper presents a simple model of a heaving oscillating buoy, represented by a surface-piercing cylinder, extracting power by means of a hydraulic system. The hydrodynamic behaviour of the absorber is modelled through application of the linear water wave theory. Apart from the basic elements listed above, the model of the hydraulic system includes leakages and pressure losses and takes into account the compressibility of the fluid. Also possible extra accumulators are considered in order to improve the performance of the hydraulic system by means of properly controlled valves. The function of these extra accumulators consists in storing and releasing energy to the system when this is desirable for the improvement of the power output. Simulations were carried out through a time-domain approach making use of the Cummins equation and considering regular monochromatic waves and irregular wave-trains. The control of the system is managed by means of control valves whose opening will be depending on the sign of the velocity of the buoy and the pressure levels. Three possible aims were assumed for the control strategies investigated: maximisation of the average power output, stabilisation of the output (in terms of rotational velocity and/or electrical power) and stabilisation of the pressures inside the accumulators (also for survivability of the hydraulic equipment). Different control variables are analysed depending on the wave inputs considered in order to improve the power extraction of the converter: Firstly the torque of the electric generator is considered as a primary way to modify the load of the PTO. Then extra accumulators are used as storing devices to perform a kind of phase control on the buoy. The benefit of this effect will be dependent on the instant of activation of the valves that connect them to the circuit and the influence of possible delays or anticipations will be investigated The results prove that it is possible to achieve a great enhancement of the power extraction with the implementation of these control strategies and that a possible combination of some of them might be beneficial for a better efficiency of the components. Moreover the application of sophisticated strategies could imply a less demanding requirement for specific equipments; such as the case of the electrical generator.

Ricci, P.; Lopez, J.; Santos, M.; Villate, J.L.; Ruiz Minguela, P.; Salcedo, F. [Tecnalia-Energia Sede de Robotiker-Tecnalia, Parque Tecnologico, Edificio 202, E-48170, Zamudio (Spain); Falcao, A.F.de O. [IDMEC, Instituto Superior Tecnico, Av. Rovisco Pais, 1, 1049-001, Lisbon (Portugal)

2009-07-01

159

WATER ENERGY IN HYDROAMELIORATIVE SYSTEMS USING THE HYDRAULIC TRANSFORMER TYPE A. BARGLAZAN AND THE HYDRAULIC HAMMER (HYDRAULIC PUMP  

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents two examples of exploitation of water energy that can be used in the irrigation field. First of theseexamples is the hydraulic transformer type A. Barglazan used for irrigation, pumped water is taken directly from theriver’s well, using a hydraulic pump which simultaneously carried out a double transformation in this way: hydraulicenergy into mechanic energy and mechanical energy into hydraulic energy. Technology preparation and devices designwas done in record time, seeing that this constructive solution is more robust, reliable and with improved energyperformance versus the laboratory prototype. The experimental research which was made at 1:1 scale proved theirgood function over time. Another example is the hydraulic hammer (hydraulic pump that uses low-head energy topump water, with a global efficiency of about 10 - 50%. Currently, the new situation of private ownership of landprovides conditions for new pumping microstations to be made where irrigation is necessary and optimal hydrauliclocations exist.

Teodor Eugen Man

2010-01-01

160

The 25 kWe solar thermal Stirling hydraulic engine system: Conceptual design  

Science.gov (United States)

The conceptual design and analysis of a solar thermal free-piston Stirling hydraulic engine system designed to deliver 25 kWe when coupled to a 11 meter test bed concentrator is documented. A manufacturing cost assessment for 10,000 units per year was made. The design meets all program objectives including a 60,000 hr design life, dynamic balancing, fully automated control, more than 33.3 percent overall system efficiency, properly conditioned power, maximum utilization of annualized insolation, and projected production costs. The system incorporates a simple, rugged, reliable pool boiler reflux heat pipe to transfer heat from the solar receiver to the Stirling engine. The free-piston engine produces high pressure hydraulic flow which powers a commercial hydraulic motor that, in turn, drives a commercial rotary induction generator. The Stirling hydraulic engine uses hermetic bellows seals to separate helium working gas from hydraulic fluid which provides hydrodynamic lubrication to all moving parts. Maximum utilization of highly refined, field proven commercial components for electric power generation minimizes development cost and risk.

White, Maurice; Emigh, Grant; Noble, Jack; Riggle, Peter; Sorenson, Torvald

1988-01-01

161

Research on MEMS sensor in hydraulic system flow detection  

Science.gov (United States)

With the development of mechatronics technology and fault diagnosis theory, people regard flow information much more than before. Cheap, fast and accurate flow sensors are urgently needed by hydraulic industry. So MEMS sensor, which is small, low cost, well performed and easy to integrate, will surely play an important role in this field. Based on the new method of flow measurement which was put forward by our research group, this paper completed the measurement of flow rate in hydraulic system by setting up the mathematical model, using numerical simulation method and doing physical experiment. Based on viscous fluid flow equations we deduced differential pressure-velocity model of this new sensor and did optimization on parameters. Then, we designed and manufactured the throttle and studied the velocity and pressure field inside the sensor by FLUENT. Also in simulation we get the differential pressure-velocity curve .The model machine was simulated too to direct experiment. In the static experiments we calibrated the MEMS sensing element and built some sample sensors. Then in a hydraulic testing system we compared the sensor signal with a turbine meter. It presented good linearity and could meet general hydraulic system use. Based on the CFD curves, we analyzed the error reasons and made some suggestion to improve. In the dynamic test, we confirmed this sensor can realize high frequency flow detection by a 7 piston-pump.

Zhang, Hongpeng; Zhang, Yindong; Liu, Dong; Ji, Yulong; Jiang, Jihai; Sun, Yuqing

2011-05-01

162

Digital robust control of throttled variable displacement hydraulic motors in aircraft power drive units  

OpenAIRE

The introduction of variable displacement hydraulic motors to secondary and primary flight actuation offers a considerable potential for power optimization and saving in aircraft hydraulic systems. The application in aircraft systems requires high safety, reliability and availability at the smallest expense possible. Therefore the combination of a variable displacement hydraulic motor with a fixed orifice guarantees fail-passive system behavior. The integration in fly-by-wire flight contro...

Biedermann, Olaf

2000-01-01

163

Influence of hydraulics and control of thermal storage in solar assisted heat pump combisystems  

OpenAIRE

This paper studies the influence of hydraulics and control of thermal storage in systems combined with solar thermal and heat pump for the production of warm water and space heating in dwellings. A reference air source heat pump system with flat plate collectors connected to a combistore was defined and modeled together with the IEA SHC Task 44 / HPP Annex 38 (T44A38) “Solar and Heat Pump Systems” boundary conditions of Strasbourg climate and SFH45 building. Three and four pipe connection...

Poppi, Stefano; Bales, Chris

2014-01-01

164

Compound Velocity Synchronizing Control Strategy for Electro-Hydraulic Load Simulator and Its Engineering Application.  

Science.gov (United States)

An electro-hydraulic load simulator (EHLS) is a typical case of torque systems with strong external disturbances from hydraulic motion systems. A new velocity synchronizing compensation strategy is proposed in this paper to eliminate motion disturbances, based on theoretical and experimental analysis of a structure invariance method and traditional velocity synchronizing compensation controller (TVSM). This strategy only uses the servo-valve's control signal of motion system and torque feedback of torque system, which could avoid the requirement on the velocity and acceleration signal in the structure invariance method, and effectively achieve a more accurate velocity synchronizing compensation in large loading conditions than a TVSM. In order to facilitate the implementation of this strategy in engineering cases, the selection rules for compensation parameters are proposed. It does not rely on any accurate information of structure parameters. This paper presents the comparison data of an EHLS with various typical operating conditions using three controllers, i.e., closed loop proportional integral derivative (PID) controller, TVSM, and the proposed improved velocity synchronizing controller. Experiments are conducted to confirm that the new strategy performs well against motion disturbances. It is more effective to improve the tracking accuracy and is a more appropriate choice for engineering applications. PMID:24895465

Han, Songshan; Jiao, Zongxia; Yao, Jianyong; Shang, Yaoxing

2014-09-01

165

Method for enhancement of sequential hydraulic fracturing using control pulse fracturing  

Energy Technology Data Exchange (ETDEWEB)

A method is described for creating multiple sequential hydraulic fractures via hydraulic fracturing combined with controlled pulse fracturing where two wells are utilized comprising: (a) drilling and completing a first and second well so that the wells will be in fluid communication with each other after subsequent fracturing in each well; (b) creating more than two simultaneous multiple vertical fractures via a controlled pulse fracturing method in the second well; (c) thereafter hydraulically fracturing the reservoir via the first well thereby creating fractures in the reservoir and afterwards shutting-in the first well without any induced pressure; (d) applying thereafter hydraulic pressure to the reservoir via the second well in an amount sufficient to fracture the reservoir thereby forming a first hydraulic fracture perpendicular to the least principal in-situ stress; (e) maintaining the hydraulic pressure on the reservoir while pumping via the second well alternate slugs of a thin-fluid spacer and a temporary blocking agent having a proppant therein whereupon a second hydraulic fracture is initiated; (f) maintaining the hydraulic pressure on the second well while pumping alternate slugs of spacer and blocking agent into the second hydraulic fracture thereby causing the second hydraulic fracture to propagate away from the first hydraulic fracture in step (e) in a curved trajectory which intersects a fracture created in the first well; (g) maintaining the hydraulic pressure while pumping as in step (f) whereupon another hydraulic fracture initiates causing another curved fracture trajectory to form and intersect the fracture created in the first well; and (h) repeated steps (f) and (g) until a desired number of hydraulic fractures are created which allows a substantial improvement in removing a natural resource from the reservoir.

Jennings, A.R. Jr.; Strubhar, M.K.

1993-07-20

166

Modeling and Experimental Tests on the Hydraulically Driven Control Rod option for IRIS Reactor  

International Nuclear Information System (INIS)

The adoption of Internal Control Rod Drive Mechanisms (ICRDMs) represents a valuable alternative to classical, external CRDMs based on electro-magnetic devices, as adopted in current PWRs. The advantages on the safety features of the reactor are apparent: inherent elimination of the Rod Ejection accidents and of possible concerns about the vessel head penetrations. A further positive feedback on the design is the reduction of the primary system overall dimensions. Within the frame of the ICRDM concepts, the Hydraulically Driven Control Rod solution is investigated as a possible option for the IRIS integral reactor. After a brief comparison of the solutions currently proposed for integral reactors, the configuration of the Hydraulic Control Rod device for IRIS, made up by an external movable piston and an internal fixed cylinder, is described. A description of the whole control system is reported as well. Particular attention is devoted to the Control Rod profile characterization, performed by means of a Computational Fluid Dynamics (CFD) analysis. The investigation of the system behavior has been carried out, including the dynamic equilibrium and its stability properties, the withdrawal and insertion step movement and the sensitivity study on command time periods. A suitable dynamic model has been set up for the mentioned purposes: the models corresponding to the various Control Rod system devices have been written in an Object-Oriented language (Modelica), thus allowt-Oriented language (Modelica), thus allowing an easy implementation of such a system into the simulator for the whole reactor. Finally, a preliminary low pressure, low temperature, reduced length experimental facility has been built. Tests on HDCR stability and operational transients have been performed. The results are compared with the dynamic system model and CFD simulation model, showing good agreement between simulations and experimental data. During these preliminary tests, the control system performed correctly, allowing stable dynamic equilibrium positions for the Control Rod and stable behavior during withdrawal and insertion steps. (authors)

167

Hydraulic blowdown TVA system for the Castor 120 motor program  

Science.gov (United States)

The performance and reliability of a low-cost hydraulic blowdown system for expendable launch vehicles (ELVs) are demonstrated in the context of the Castro 120 motor program. Test results are reported which show that the blowdown system meets or exceeds the performance objectives for an ELV motor in a Stage I, Stage II, or strap-on application. The primary cost savings include replacement of the expensive turbine pump and auxiliary power source and the use of a simplified actuator design.

Lee, R. G.; Olsen, G. E.; Trowbridge, C. G.; Griffis, D. M.

1993-06-01

168

The root system as a hydraulic architecture: principles and applications  

OpenAIRE

Many hydrological models including the process of root water uptake (RWU) do not consider the dimension of root system hydraulic architecture (HA) because explicitly solving water flow in such a complex system is too time consuming. However, they might lack process understanding when basing RWU and plant water stress predictions on functions of variables such as the root length density distribution. On the basis of analytical solutions of water flow equations in a HA, we developed and validat...

Couvreur, Valentin; Meunier, Fe?licien; Vanderborght, Jan; Javaux, Mathieu; Hydrus, Workshop

2013-01-01

169

Aircraft hydraulic power system diagnostic, prognostics and health management  

OpenAIRE

This Individual Research Project (IRP) is the extension research to the group design project (GDP) work which the author has participated in his Msc programme. The GDP objective is to complete the conceptual design of a 200-seat, flying wing civil airliner—FW-11. The next generation aircraft design demands higher reliability, safety and maintainability. With the development of the vehicle hydraulic system technology, the equipment and systems become more and more complex, their reliabili...

Wang, Jian

2012-01-01

170

Transputers in Fluid Power - Design and Applications. Chapter 5 in Advances in Hydraulic Control Systems. : A SERG Publication - SERG: Subsea Engineering Research Group.  

DEFF Research Database (Denmark)

Deals with results and trends on mechatronics in fluid power and intelligent control of machines and robots. New results are presented concerning transputer-basen distributed control of machines and robots. Experimental results with the DTU mechatronic test facility are presented and discussed. Several adaptive control algoritms are investigated and evaluated. Promissing results are obtained with Computed Valve-Input Control (CIC), Adaptive Model-based Actuator Control (AMAC) and Linear Pertubation Adaptive Control (LPAC).

Conrad, Finn

1996-01-01

171

Hydraulic Soft Yaw System Load Reduction and Prototype Results  

DEFF Research Database (Denmark)

Introducing a hydraulic soft yaw concept for wind turbines leads to significant load reductions in the wind turbine structure. The soft yaw system operates as a shock absorption system on a car, hence absorbing the loading from turbulent wind conditions instead of leading them into the stiff wind turbine structure. Results presented shows fatigue reductions of up to 40% and ultimate load reduction of up to 19%. The ultimate load reduction increases even more when the over load protection system in the hydraulic soft yaw system is introduced and results show how the exact extreme load cut off operates. Further it is analyzed how the soft yaw system influence the power production of the turbine. It is shown that the influence is minimal, but at larger yaw errors the effect is possitive. Due to the implemeted functions in the hydraulic soft yaw system such as even load distribution on the pinions, fatigue and ultimate load reduction and backlash compensation it is possible to increase the number of yaw activations without compromising the lifetime of the components. By increasing the number of activations, the average yaw error may be lowered and hence the energy production raised below rated wind speed.

Stubkier, SØren; Pedersen, Henrik C.

2013-01-01

172

Optimisation of Working Areas in Discrete Hydraulic Power Take off-system for Wave Energy Converters  

DEFF Research Database (Denmark)

Fluid power is the leading technology in Power Take Off(PTO) systems in Wave Energy Converters(WEC’s), due to the capability of generating high force at low velocity. However, as hydraulic force controlling system may suffer from large energy losses the efficiency of the hydraulic PTO systems may be a limiting factor for wave energy. Therefore, a secondary controlled force system has been proposed as PTO element for WEC’s. This paper investigates the configuration of a multi-chamber cylinder utilising two common pressure lines. By usage of model based optimisation an optimal number and size of working areas is proposed. This area encoding strategy is investigated and compared to two standard binary encodings, finding that the optimised area coding yields significantly higher energy output.

Hansen, Anders Hedegaard; Hansen, Rico Hjerm

2012-01-01

173

Hydraulic Yaw System for Wind Turbines with New Compact Hydraulic Motor Principle  

DEFF Research Database (Denmark)

This paper presents a new hydraulic yaw system for wind turbines. The basic component is a new type of hydraulic motor characterized by an extraordinary high specific displacement yielding high output torque in a compact form. The focus in the paper is the volumetric efficiency of the motor, which is based on leakage flow. The most critical gaps in the motor, across the end faces of the rotor, are investigated both by a fluid structural interaction simulation model and by experimental prototype tests. The simulation model is the basis for the motor design and the manufacturing tolerances. The volumetric efficiency is highly dependent on the structural deflections caused by the pressure distribution in the fluid films across the rotor. This gap height is measured with a 0.1?m resolution "SMAC Moving Coil Actuator" in the experimental test setup. When the pressure in the pressure compensation volumes is minimizing the deflections, the measured gap height is around ? = 10?m and the volumetric efficiency of the motor is around ?v = 0.85. By decreasing the initial gaps from the manufacturing process, this volumetric efficiency can be further increased.

SØrensen, Rasmus MØrk; Hansen, Michael Rygaard

2011-01-01

174

Engine having a high pressure hydraulic system and low pressure lubricating system  

Science.gov (United States)

An engine includes a high pressure hydraulic system having a high pressure pump and at least one hydraulically-actuated device attached to an engine housing. A low pressure engine lubricating system is attached to the engine housing and includes a circulation conduit fluidly connected to an outlet from the high pressure pump.

Bartley, Bradley E. (Manito, IL); Blass, James R. (Bloomington, IL); Gibson, Dennis H. (Chillicothe, IL)

2000-01-01

175

Thermal-hydraulic tests for reactor safety system  

International Nuclear Information System (INIS)

Tests for the safety depressurization system, Sparger adopted for the Korean next generation reactor, APR1400 are carried out for several geometries with the B and C (Blowdown and Condensation) facility in the condition of high temperature and pressure and with a small test facility in the condition of atmospheric temperature and pressure. Tests for the critical heat flux are performed with the RCS(Reactor Coolant System) facility as well as with the Freon CHF Loop in the condition of high temperature and pressure. The atmospheric temperature and pressure facility is utilized for development of the high standard thermal hydraulic measurement technology. The optical method is developed to measure the local thermal-hydraulic behavior for the single and two-phase boiling phenomena

176

Sulphur compounds in a hydraulic ash-disposal system  

International Nuclear Information System (INIS)

In the retorting process of Estonian oil shale over half of the sulphur occurring in the feed shale remains in the solid residue. Sulphide in the form of iron and calcium sulphides is environmentally the most dangerous. This paper discusses the mechanism and the rate of hydrolysis and oxidation reactions of sulphur compounds in the hydraulic ash-disposal system. 3 figs., tab., 4 refs

177

Hydraulic External Pre-Isolator System for LIGO  

OpenAIRE

The Hydraulic External Pre-Isolator (HEPI) is the first 6 degrees of freedom active seismic isolation system implemented at the Laser Interferometer Gravitational Wave Observatory (LIGO). Implementation was first completed at the LIGO Livingston Observatory (LLO) prior to LIGO's 5th science run, successfully cutting down the disturbance seen by LLO's suspended optics in the two most prominent seismic disturbance bands, the microseism (0.1-0.3Hz) and the anthropogenic (1-3Hz)...

Wen, S.; Mittleman, R.; Mason, K.; Giaime, J.; Abbott, R.; Kern, J.; O Reilly, B.; Bork, R.; Hammond, M.; Hardham, C.; Lantz, B.; Hua, W.; Coyne, D.; Traylor, G.; Overmier, H.

2013-01-01

178

Study on Knowledge -based Intelligent Fault Diagnosis of Hydraulic System  

OpenAIRE

A general framework of hydraulic fault diagnosis system was studied. It consisted of equipment knowledge bases, real-time databases, fusion reasoning module, knowledge acquisition module and so on. A tree-structure model of fault knowledge was established. Fault nodes knowledge was encapsulated by object-oriented technique. Complete knowledge bases were made including fault bases and diagnosis bases. It could describe the fault positions, the structure of fault, cause-symptom relationships, d...

Xuexia Liu

2012-01-01

179

Developing a Tool Point Control Scheme for a Hydraulic Crane Using Interactive Real-time Dynamic Simulation  

DEFF Research Database (Denmark)

This paper describes the implementation of an interactive real-time dynamic simulation model of a hydraulic crane. The user input to the model is given continuously via joystick and output is presented continuously in a 3D animation. Using this simulation model, a tool point control scheme is developed for the specific crane, considering the saturation phenomena of the system and practical implementation.

Pedersen, Mikkel Melters; Hansen, Michael Rygaard

2010-01-01

180

Hydraulic tests of emergency cooling system: L-Area  

International Nuclear Information System (INIS)

The delay in L-Area startup provided an opportunity to obtain valuable data on the Emergency Cooling System (ECS) which will permit reactor operation at the highest safe power level. ECS flow is a major input to the FLOOD code which calculates reactor ECS power limits. The FLOOD code assesses the effectiveness of the ECS cooling capacity by modeling the core and plenum hydraulics under accident conditions. Presently, reactor power is not limited by the ECS cooling capacity (power limit). However, the manual calculations of ECS flows had been recently updated to include piping changes (debris strainer, valve changes, pressure release systems) and update fitting losses. Both updates resulted in reduced calculated ECS flows. Upon completion of the current program to update, validate, and document, reactor power may be limited under certain situations by ECS cooling capacity for some present reactor charge designs. A series of special hydraulic tests (Reference 1, 3) were conducted in L-Area using all sources of emergency coolant including the ECS pumps (Reference 2). The tests provided empirical hydraulic data on the ECS piping. These data will be used in computer models of the system as well as manual calculations of ECS flows. The improved modeling and accuracy of the flow calculations will permit reactor operation at the highest safe power level with respect to an ECS power limit

181

Engine having hydraulic and fan drive systems using a single high pressure pump  

Science.gov (United States)

An engine comprises a hydraulic system attached to an engine housing that includes a high pressure pump and a hydraulic fluid flowing through at least one passageway. A fan drive system is also attached to the engine housing and includes a hydraulic motor and a fan which can move air over the engine. The hydraulic motor includes an inlet fluidly connected to the at least one passageway.

Bartley, Bradley E. (Manito, IL); Blass, James R. (Bloomington, IL); Gibson, Dennis H. (Chillicothe, IL)

2000-01-01

182

Thermal-Hydraulic Experiments and Modelling for Advanced Nuclear Reactor Systems  

International Nuclear Information System (INIS)

The objectives of the project are to study thermal hydraulic characteristics of advanced nuclear reactor system for evaluating key thermal-hydraulic phenomena relevant to new safety concepts. To meet the research goal, several thermal hydraulic experiments were performed and related thermal hydraulic models were developed with the experimental data which were produced through the thermal hydraulic experiments. The Followings are main research topics: - Multi-dimensional Phenomena in a Reactor Vessel Downcomer - Condensation-induced Thermal Mixing in a Pool - Development of Thermal-Hydraulic Models for Two-Phase Flow - Construction of T-H Data Base

183

Application research on hydraulic coke cutting monitoring system based on optical fiber sensing technology  

Science.gov (United States)

With the development of the optical fiber sensing technology, the acoustic emission sensor has become one of the focal research topics. On the basis of studying the traditional hydraulic coke cutting monitoring system, the optical fiber acoustic emission sensor has been applied in the hydraulic coke cutting monitoring system for the first time, researching the monitoring signal of the optical fiber acoustic emission sensor in the system. The actual test results show that using the acoustic emission sensor in the hydraulic coke cutting monitoring system can get the real-time and accurate hydraulic coke cutting state and the effective realization of hydraulic coke cutting automatic monitoring in the Wuhan Branch of Sinopec.

Zhong, Dong; Tong, Xinglin

2014-06-01

184

Nanocoatings for High-Efficiency Industrial Hydraulic and Tooling Systems  

Energy Technology Data Exchange (ETDEWEB)

Industrial manufacturing in the U.S. accounts for roughly one third of the 98 quadrillion Btu total energy consumption. Motor system losses amount to 1.3 quadrillion Btu, which represents the largest proportional loss of any end-use category, while pumps alone represent over 574 trillion BTU (TBTU) of energy loss each year. The efficiency of machines with moving components is a function of the amount of energy lost to heat because of friction between contacting surfaces. The friction between these interfaces also contributes to downtime and the loss of productivity through component wear and subsequent repair. The production of new replacement parts requires additional energy. Among efforts to reduce energy losses, wear-resistant, low-friction coatings on rotating and sliding components offer a promising approach that is fully compatible with existing equipment and processes. In addition to lubrication, one of the most desirable solutions is to apply a protective coating or surface treatment to rotating or sliding components to reduce their friction coefficients, thereby leading to reduced wear. Historically, a number of materials such as diamond-like carbon (DLC), titanium nitride (TiN), titanium aluminum nitride (TiAlN), and tungsten carbide (WC) have been examined as tribological coatings. The primary objective of this project was the development of a variety of thin film nanocoatings, derived from the AlMgB14 system, with a focus on reducing wear and friction in both industrial hydraulics and cutting tool applications. Proof-of-concept studies leading up to this project had shown that the constituent phases, AlMgB14 and TiB2, were capable of producing low-friction coatings by pulsed laser deposition. These coatings combine high hardness with a low friction coefficient, and were shown to substantially reduce wear in laboratory tribology tests. Selection of the two applications was based largely on the concept of improved mechanical interface efficiencies for energy conservation. In mobile hydraulic systems, efficiency gains through low friction would translate into improved fuel economy and fewer greenhouse gas emissions. Stationary hydraulic systems, accordingly, would consume less electrical power. Reduced tooling wear in machining operations would translate to greater operating yields, while lowering the energy consumed during processing. The AlMgB14 nanocoatings technology progressed beyond baseline laboratory tests into measurable energy savings and enhancements to product durability. Three key hydraulic markets were identified over the course of the project that will benefit from implementation: industrial vane pumps, orbiting valve-in-star hydraulic motors, and variable displacement piston pumps. In the vane pump application, the overall product efficiency was improved by as much as 11%. Similar results were observed with the hydraulic motors tested, where efficiency gains of over 10% were noted. For variable displacement piston pumps, overall efficiency was improved by 5%. For cutting tools, the most significant gains in productivity (and, accordingly, the efficiency of the machining process as a whole) were associated with the roughing and finishing of titanium components for aerospace systems. Use of the AlMgB14 nanocoating in customer field tests has shown that the coated tools were able to withstand machining rates as high as 500sfm (limited only by the substrate material), with relatively low flank wear when compared to other industrial offerings. AlMgB14 coated tools exhibited a 60% improvement over similarly applied TiAlN thin films. Furthermore, AlMgB14-based coatings in these particular tests lasted twice as long than their TiAlN counterparts at the 500sfm feed rates. Full implementation of the technology into the industrial hydraulic and cutting tool markets equates to a worldwide energy savings of 46 trillion BTU/year by 2030. U.S.-based GHG emissions associated with the markets identified would fall accordingly, dropping by as much as 50,000 tonnes annually.

Clifton B. Higdon III

2011-01-07

185

Thermal-hydraulics of lead bismuth for accelerator driven systems  

International Nuclear Information System (INIS)

Full text of publication follows: Lead bismuth has been selected as one of the most suitable coolants to be used in accelerator driven systems (ADS) for transmutation of minor actinides. It serves both, as a target material of the spallation source to balance the neutron economy, and as a coolant with high thermal inertia to provide a safe and reliable heat transfer to the secondary power cycle. With the aim to develop the required technologies to enable the later design of such ADS systems, the Karlsruhe Lead bismuth LAboratory KALLA, consisting of three test loops, has been built and set into operation at the Forschungszentrum Karlsruhe since 2000, keeping more than 45 t of PbBi in operation at temperatures up to 550 deg. C. The test program includes oxygen control systems, heat flux simulation tools, electro-magnetic and mechanical pump technologies, heat transfer and flow measurements, reliability and corrosion tests. In a first test campaign, a technology loop called THESYS was built to develop measurement technologies for the acquisition of scalar quantities, like pressures, temperatures, concentrations, and flow rates, as well as velocity fields, which are required for both operational and scientific purposes. THESYS also allowed to perform generic turbulent heat transfer experiments necessary to provide liquid metal adapted turbulent heat transfer models for ADS design analyses. The second loop, the thermalhydraulic loop THEADES with an installed power of 2.5 op THEADES with an installed power of 2.5 MW, has been built to conduct prototypical component experiments for beam windows (e.g. MEGAPIE or MYHRRA) or fuel rod configurations. First test results will be reported. The experimental team is supported by a numerical team who studied the thermal hydraulics of the tested components in order to enable a later transfer of the results to industrial systems. Three different types of codes are being improved: lumped parameter codes (e.g. ATHLET) to perform system analyses for lead bismuth in loops, targets, pumps and heat exchangers, CFD codes (e.g. CFX) to analyse local phenomena in thermally highly loaded components, and sub-channel codes (e.g. MATRA) to be used later for fuel assembly design. Heat transfer correlations and turbulence models were checked against measured data for validation. In addition, a direct numerical simulation of selected cases could provide further insight into the nature of turbulence in liquid lead bismuth. The paper is intended to give an overview of the numerous results achieved up to now. (authors)

186

46 CFR 128.240 - Hydraulic or pneumatic power and control-materials and pressure design.  

Science.gov (United States)

...hydraulic or pneumatic component (such as control valves, check valves, relief valves, and regulators) may be accepted by the cognizant...component's burst pressure. Burst-pressure testing is described in ANSI B 31.1, Paragraph...

2010-10-01

187

Control rod blow out protection system  

International Nuclear Information System (INIS)

A control system is described which is comprised of a plurality of low worth absorber elements with individual hydraulic actuator assemblies, positioned within the reactor vessel. Axial distortions and safety hazards are minimized by this arrangement. (E.C.B.)

188

Non-linear modelling and optimal control of a hydraulically actuated seismic isolator test rig  

Science.gov (United States)

This paper investigates the modelling, parameter identification and control of an unidirectional hydraulically actuated seismic isolator test rig. The plant is characterized by non-linearities such as the valve dead zone and frictions. A non-linear model is derived and then employed for parameter identification. The results concerning the model validation are illustrated and they fully confirm the effectiveness of the proposed model. The testing procedure of the isolation systems is based on the definition of a target displacement time history of the sliding table and, consequently, the precision of the table positioning is of primary importance. In order to minimize the test rig tracking error, a suitable control system has to be adopted. The system non-linearities highly limit the performances of the classical linear control and a non-linear one is therefore adopted. The test rig mathematical model is employed for a non-linear control design that minimizes the error between the target table position and the current one. The controller synthesis is made by taking no specimen into account. The proposed approach consists of a non-linear optimal control based on the state-dependent Riccati equation (SDRE). Numerical simulations have been performed in order to evaluate the soundness of the designed control with and without the specimen under test. The results confirm that the performances of the proposed non-linear controller are not invalidated because of the presence of the specimen.

Pagano, Stefano; Russo, Riccardo; Strano, Salvatore; Terzo, Mario

2013-02-01

189

Downhole hydraulic seismic generator  

Science.gov (United States)

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

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

1992-01-01

190

Hydraulic characterisation of karst systems with man-made tracers  

International Nuclear Information System (INIS)

Tracer experiments using man-made tracers are common in hydrogeological exploration of groundwater aquifers in karst systems. In the present investigation, a convection-dispersion model (multidispersion model with consideration of several flow paths) and a single-cleft model (consideration of the diffusion between the cleft and the surrounding rock matrix) were used for evaluating tracer experiments in the main hydrological system of the saturated zone of karst systems. In addition to these extended analytical solutions, a numerical transport model was developed for investigating the influence of the transient flow rate on the flow and transport parameters. Comparative evaluations of the model approaches for the evaluation of tracer experiments were made in four different karst systems: Danube-Aach, Paderborn, Slowenia and Lurbach, of which the Danube-Aach system was considered as the most important. The investigation also comprised three supplementary experiments in order to enable a complete hydraulic characterisation of the system. (orig./SR)

191

Hydraulic model study on pump sump configuration for cooling water systems of nuclear power plants  

International Nuclear Information System (INIS)

Cooling water systems of nuclear power plants play a key role in power plant operation. In particular, the ESWS (Essential Service Water System) supplies seawater as the cooling water to remove heat from the safety-related CCWS (Component Cooling Water System) via the CCW heat exchanger. The amount of cooling water required in a 1000 MW nuclear power plant is more than 50 m3/sec for each unit. Thus, it is important that the intake pumps for the cooling water are designed for proper performance. To ensure the stable pump performance, the water flow into the pump bell mouth should be in uniform and steady conditions. These flow conditions are controlled both by the location of the pump in the sump and the configuration of intake sump structure. In terms of the design, the preliminary configuration of the sump proceeds the hydraulic model study. The preliminary configuration of the sump can be determined using design guides such as HIS (Hydraulic Institute Standards) which has been standardized based on many experiments for sump structures. According to these guides, the dimension of the sump depends primarily on the diameter of pump's bell mouth. Although the preliminary configuration of sump is made using the diameter of the bell mouth, the adequacy of the preliminary configuration should be verified by a hydraulic model study to confirm whether or not the approaching flow meets the required flow condition without swirls, tornadoes and vortices. The hydrauliirls, tornadoes and vortices. The hydraulic model study is indispensable tool to determine if the preliminary configuration of the sump is appropriate. If poor flow conditions are indicated, the configuration is revised and / or the flow improving devices are provided in the sump. This technical report focuses on the preliminary configuration of the intake sump structure and the hydraulic model study for the sump. (author)

192

Thermo-hydraulic analysis of the windowless target system  

Energy Technology Data Exchange (ETDEWEB)

The target system, whose function is to supply an external neutron source to a subcritical core in order to sustain the neutron chain reaction, is the most critical part of an ADS being subject to severe thermo-mechanical loading and material damage due to accelerator protons and fission neutrons. In order to reduce the material damage and to increase the life of the target system a windowless option was chosen in the framework of the European PDS-XADS project as reference configuration for the experimental ADS cooled by lead-bismuth eutectic alloy. This document deals with the results of the thermo-hydraulic analysis performed with STAR-CD and RELAP5 codes to assess the behaviour of the windowless target system during off-normal operating conditions. It also reports a description of modifications properly implemented in the codes for studying this kind of plant. The windowless target system shows a satisfactory thermo-hydraulic behaviour for the analysed accidents, except for the loss of both pumps without proton beam shut-off and for the beam trips lasting more than 1 s.

Bianchi, Fosco [ENEA, Via Martiri di Monte Sole 4, 40129 Bologna (Italy)], E-mail: fosco.bianchi@bologna.enea.it; Ferri, Roberta [SIET, Via Nino Bixio 27, 29100 Piacenza (Italy); Moreau, Vincent [CRS4, Polaris Edificio 1 CP25, 09010 Pula (Canada) (Italy)

2008-08-15

193

Vadose zone monitoring strategies to control water flux dynamics and changes in soil hydraulic properties.  

Science.gov (United States)

For monitoring the vadose zone, different strategies can be chosen, depending on the objectives and scale of observation. The effects of non-conventional water use on the vadose zone might produce impacts in porous media which could lead to changes in soil hydraulic properties, among others. Controlling these possible effects requires an accurate monitoring strategy that controls the volumetric water content, ?, and soil pressure, h, along the studied profile. According to the available literature, different monitoring systems have been carried out independently, however less attention has received comparative studies between different techniques. An experimental plot of 9x5 m2 was set with automatic and non-automatic sensors to control ? and h up to 1.5m depth. The non-automatic system consisted of ten Jet Fill tensiometers at 30, 45, 60, 90 and 120 cm (Soil Moisture®) and a polycarbonate access tube of 44 mm (i.d) for soil moisture measurements with a TRIME FM TDR portable probe (IMKO®). Vertical installation was carefully performed; measurements with this system were manual, twice a week for ? and three times per week for h. The automatic system composed of five 5TE sensors (Decagon Devices®) installed at 20, 40, 60, 90 and 120 cm for ? measurements and one MPS1 sensor (Decagon Devices®) at 60 cm depth for h. Installation took place laterally in a 40-50 cm length hole bored in a side of a trench that was excavated. All automatic sensors hourly recorded and stored in a data-logger. Boundary conditions were controlled with a volume-meter and with a meteorological station. ET was modelled with Penman-Monteith equation. Soil characterization include bulk density, gravimetric water content, grain size distribution, saturated hydraulic conductivity and soil water retention curves determined following laboratory standards. Soil mineralogy was determined by X-Ray difractometry. Unsaturated soil hydraulic parameters were model-fitted through SWRC-fit code and ROSETTA based on soil textural fractions. Simulation of water flow using automatic and non-automatic date was carried out by HYDRUS-1D independently. A good agreement from collected automatic and non-automatic data and modelled results can be recognized. General trend was captured, except for the outlier values as expected. Slightly differences were found between hydraulic properties obtained from laboratory determinations, and from inverse modelling from the two approaches. Differences up to 14% of flux through the lower boundary were detected between the two strategies According to results, automatic sensors have more resolution and then they're more appropriated to detect subtle changes of soil hydraulic properties. Nevertheless, if the aim of the research is to control the general trend of water dynamics, no significant differences were observed between the two systems.

Valdes-Abellan, Javier; Jiménez-Martínez, Joaquin; Candela, Lucila

2013-04-01

194

Study on Knowledge -based Intelligent Fault Diagnosis of Hydraulic System  

Directory of Open Access Journals (Sweden)

Full Text Available A general framework of hydraulic fault diagnosis system was studied. It consisted of equipment knowledge bases, real-time databases, fusion reasoning module, knowledge acquisition module and so on. A tree-structure model of fault knowledge was established. Fault nodes knowledge was encapsulated by object-oriented technique. Complete knowledge bases were made including fault bases and diagnosis bases. It could describe the fault positions, the structure of fault, cause-symptom relationships, diagnosis principles and other knowledge. Taking the fault of left and right lifting oil cylinder out of sync for example, the diagnostic results show that the methods were effective.

Xuexia Liu

2012-12-01

195

Thermal and hydraulic analyses of the System 81 cold traps  

Energy Technology Data Exchange (ETDEWEB)

Thermal and hydraulic analyses of the System 81 Type I and II cold traps were completed except for thermal transients analysis. Results are evaluated, discussed, and reported. Analytical models were developed to determine the physical dimensions of the cold traps and to predict the performance. The FFTF cold trap crystallizer performances were simulated using the thermal model. This simulation shows that the analytical model developed predicts reasonably conservative temperatures. Pressure drop and sodium residence time calculations indicate that the present design will meet the requirements specified in the E-Specification. Steady state temperature data for the critical regions were generated to assess the magnitude of the thermal stress.

Kim, K.

1977-06-15

196

Nuclear reactor with a control rod with hydraulic drive  

International Nuclear Information System (INIS)

An additional inlet opening for hydraulic liquids is provided in the bypass at the rear end of the cylinder in the direction of flow. Together with the narrowing of the cylinder after it, it provides a definite end position of the piston relative to the cylinder. (orig./HP)

197

Robust Non-Chattering Observer Based Sliding Control Concept for Electro-Hydraulic Drives  

DEFF Research Database (Denmark)

This paper presents an observer-based sliding mode control concept with chattering reduction, generally applicable for position tracking control of electro-hydraulic valve-cylinder drives (VCD's). The proposed control concept requires only common data sheet information and no knowledge on load characteristics. Furthermore the proposed scheme only employ pistonand valve spool positions- and pressure feedback, commonly available in industry. The main target is to overcome problems with linear controllers deteriorating performance due to the inherent nonlinear nature of such systems, without requiring extensive knowledge on system parameters nor advanced control theory. In order to accomplish this task, an integral sliding mode controller designed for the control derivative employing state observation is proposed, based on a generalized reduced order model structure of a VCD with unmatched valve ow- and cylinder asymmetries. It is shown that limited attention can be given to bounds on parameter estimates, that chattering is reduced and the number of tuning parameters is reduced to the level seen in conventional PID schemes. Furthermore, simulation results demonstrate a high level of robustness when subjected to strong perturbations in supply pressure and coulomb friction force, and that tracking accuracy may be reduced to the level of noise. Furthermore, the proposed controller tolerates signicant noise levels, while still remaining stable and accurate.

Schmidt, Lasse; Andersen, Torben Ole

2013-01-01

198

Real-time neural network-based self-tuning control of a nonlinear electro-hydraulic servomotor  

Energy Technology Data Exchange (ETDEWEB)

For high power applications, hydraulic actuators offer many advantages over electromagnetic actuators, including higher torque/mass ratios; smaller control gains; excellent torque capability; filtered high frequency noise; better heat transfer characteristics; smaller size; higher speed of response of the servomechanism; cheaper hardware; and higher reliability. Therefore, any application that requires a large force applied smoothly by an actuator is a candidate for hydraulic power. Examples of such applications include vehicle steering and braking systems; roll mills; drilling rigs; heavy duty crane and presses; and industrial robots and actuators for aircraft control surfaces such as ailerons and flaps. It is extremely important to create effective control strategies for hydraulic systems. This paper outlined the real-time implementation of a neural network-based approach, for self-tuning control of the angular position of a nonlinear electro-hydraulic servomotor. Using an online training algorithm, a neural network autoregressive moving-average model with exogenous input (ARMAX) model of the system was identified and continuously updated and an optimal linear ARMAX model was determined. The paper briefly depicted the neural network-based self-tuning control approach and a description of the experimental equipment (hardware and software) was presented including the implementation details. The experimental results were discussed and conclusions were summarized. It was found that the approach proved to be very effective in the control of this fast dynamics system, outperforming a fine tuned PI controller. Therefore, although the self-tuning approach was computationally demanding, it was feasible for real-time implementation. 22 refs., 6 figs.

Canelon, J.I.; Ortega, A.G. [Univ. del Zulia, Maracaibo, Zulia (Venezuela, Bolivarian Republic of). School of Electrical Engineering; Shieh, L.S. [Houston Univ., Houston, TX (United States). Dept. of Electrical and Computer Engineering; Bastidas, J.I. [Univ. del Zulia, Maracaibo, Zulia (Venezuela, Bolivarian Republic of). School of Mechanical Engineering; Zhang, Y.; Akujuobi, C.M. [Prairie View A and M Univ., Prairie View, TX (United States). Center of Excellence for Communication Systems Technology Research and Dept. of Engineering Technology

2010-08-13

199

Scaling of Thermal-Hydraulic Phenomena and System Code Assessment  

International Nuclear Information System (INIS)

In the last five decades large efforts have been undertaken to provide reliable thermal-hydraulic system codes for the analyses of transients and accidents in nuclear power plants. Many separate effects tests and integral system tests were carried out to establish a data base for code development and code validation. In this context the question has to be answered, to what extent the results of down-scaled test facilities represent the thermal-hydraulic behaviour expected in a full-scale nuclear reactor under accidental conditions. Scaling principles, developed by many scientists and engineers, present a scientific technical basis and give a valuable orientation for the design of test facilities. However, it is impossible for a down-scaled facility to reproduce all physical phenomena in the correct temporal sequence and in the kind and strength of their occurrence. The designer needs to optimize a down-scaled facility for the processes of primary interest. This leads compulsorily to scaling distortions of other processes with less importance. Taking into account these weak points, a goal oriented code validation strategy is required, based on the analyses of separate effects tests and integral system tests as well as transients occurred in full-scale nuclear reactors. The CSNI validation matrices are an excellent basis for the fulfilling of this task. Separate effects tests in full scale play here an important role.

200

Evaluation of Bulk Modulus of Oil System with Hydraulic Line  

Directory of Open Access Journals (Sweden)

Full Text Available The aim of the paper is to experimentally measure and ealuate bulk modulus of oil/steel pipe system and oil/hose system. The measurement was performed using experimental device on the basis of a measured pressure difference depending on time. Bulk modulus is evaluated from pressure change with known flow and volume of line. Pressure rise is caused by valve closure at the line end. Furthermore, a mathematical model of the experimental device is created using Matlab SimHydraulics software. Time dependencies of pressure for the oil/steel pipe system and the oil/hose system are simulated on this mathematical model. The simulations are verified by experiment.

Bure?ek A.

2013-04-01

201

CFD analysis of pressure loss during flow by hydraulic directional control valve constructed from logic valves  

International Nuclear Information System (INIS)

Highlights: ? Investigating the reduction of flow resistance by hydraulic directional valve. ? Replacing of directional spool valve by logic type valve mounted on the same subplate. ? Verifying the new design by CFD analysis with ANSYS/FLUENT software. ? Allowing an example of the solution to reduce pressure loss over 35–61%. ? Conducting an experimental studies to verify CFD analysis. - Abstract: The aim of this paper is to investigate the reduction of flow resistance in a hydraulic system. The undertaken matter is focused on a spool type directional control valve with pilot operated check valves. In the paper there is a proposition of replacing a 4-way directional control valve with pilot operated check valves by suitable unit consisting of logic valves. Therefore, a body of new directional control valve has been designed. Four logic valves are mounted on the body and closed with a cover on which electromagnetic pilot valve is assembled. The hydraulic ports of the body are in accordance with the standard ISO 4401 – 08-07-0-94, so the proposed new directional control valve can be applied alternatively to a directional spool valve. An important task given during the work is to create the systems of flow paths inside the body, which are assumed to be performed with simple technologies like: drilling, boring and milling. The system of the designed flow paths is verified by CFD analysis with the use of ANSYS/FLUENT program on three-dimensional model. Obtainee-dimensional model. Obtained results are compared with the results of the characteristics given in catalogues and coming from experimental research of the prototype. The difference in pressure loss during flow for the logic valve taken from CFD calculation and the catalogue do not exceed 5%. Presented in the paper directional control valve may operate for volumetric flow rate up to 450 dm3/min and the pressure up to 42 MPa. In the proposed solution, although simple technologies of making flow paths were applied, the pressure losses were reduced over 35%. The developed solution is close to a standard directional spool valve and can be assembled on an identical sub-plate.

202

Water hydraulics in hydropowerplants  

OpenAIRE

This report puts together the possibilities of water hydraulics. It also compare pros and cons of new adapted systems or when converting existing oil hydraulic systems to water hydraulics. A small comparison of environmental effects from oil and water treated for use in hydraulic systems will be made. A large question concerning water hydraulics is if it has the same durability as oil hydraulics. Another is if you get accelerated wear when you convert an oil hydraulic system to water hydrauli...

Andersson, Robert

2008-01-01

203

Application of Fuzzy Clustering in Modeling of a Water Hydraulics System  

DEFF Research Database (Denmark)

This article presents a case study of applying fuzzy modeling techniques for a water hydraulics system. The obtained model is intended to provide a basis for model-based control of the system. Fuzzy clustering is used for classifying measured input-output data points into partitions. The fuzzy model is extracted from the obtained partitions. The identified model has been evaluated by comparing measurements with simulation results. The evaluation shows that the identified model is capable of describing the system dynamics over a reasonably wide frequency range.

Zhou, Jianjun; Kroszynski, Uri

2000-01-01

204

Electromechanical propellant control system actuator  

Science.gov (United States)

New control mechanism technologies are currently being sought to provide alternatives to hydraulic actuation systems. The Propulsion Laboratory at Marshall Space Flight Center (MSFC) is involved in the development of electromechanical actuators (EMA's) for this purpose. Through this effort, an in-house designed electromechanical propellant valve actuator has been assembled and is presently being evaluated. This evaluation will allow performance comparisons between EMA and hydraulics systems. The in-house design consists of the following hardware: a three-phase brushless motor, a harmonic drive, and an output spline which will mate with current Space Shuttle Main Engine (SSME) propellant control valves. A resolver and associated electronics supply position feedback for the EMA. System control is provided by a solid-state electronic controller and power supply. Frequency response testing has been performed with further testing planned as hardware and test facilities become available.

Myers, W. Neill; Weir, Rae Ann

1990-01-01

205

Pneumatic and Hydraulic Systems in Coal Fluidized Bed Combustor  

Directory of Open Access Journals (Sweden)

Full Text Available Problem statement: This study designed the pneumatic and hydraulic systems in coal fluidized bed combustor. These are fluidization of silica sand bed material, Air distributor, centrifugal fan, electric motor power drive and surface heat exchanger. Approach: The effects of increased gas velocity on silica sand and the resultant drag force formed the basic equations in fluidization. Air distributor was introduced to achieve pressure drop across the beds. Results: The constructed centrifugal fan was driven by selected electric motor based on pressure and temperature changes in the reactor. The dimensions of the heat transfer tube were calculated from fluid flow and energy balance equations. The values obtained were as the follows: Fluidization velocity (1.54 m sec-­1, gas velocity through orifice (29.52 m sec-1, the fan electric motor (2 KW, 3 ph at 1500 pm, the steam temperature obtained was 160°C from water ambient temperature of 30°C and tube length 22 m was coiled into levels in the combustor. Conclusion/Recommendation: Precise specifications of pneumatic and hydraulic systems will adequately address the environment concern of coal fired power supply as a method to address epileptic power supply in Nigeria.

Z. O. Opafunso

2009-01-01

206

Analysis of Dither in PWM Control on Electro-hydraulic Proportional Valve  

Directory of Open Access Journals (Sweden)

Full Text Available Plus with modulation (PWM is widely used in proporational control systems for it is efficient, flexible and anti-interference. Due to the friction and hysteresis of electromagnet, hysteresis exists when hydraulic valve in steady-state, and hysteresis influences the dynamic characteristics of the valve seriously,the hysteresis can be improved by superimposing dithers with certain frequency and amplitude to the valve coil. Aiming at the character of anti-unloading power driver circuit ,this paper analyzed the parasitic dither which exists in ±24V PWM control?besides?the experiment shows that in a high frequency PWM, dither with independent frequency and amplitude can be generated by changing the frequency of the PWM, in this way, the dithers  and average current of coil  can be adjusted separately by changing PWM frequency and PWM duty cycle.  

Guoping LIU

2013-11-01

207

Transient Thermal Hydraulic Analyses of Heavy Water System  

International Nuclear Information System (INIS)

A research reactor core surrounded by a heavy water (D2O) vessel uses heavy water as a reflector. A Heavy Water System (HWS) is installed to remove the heat generated in heavy water and the vessel itself. The HWS is separated from the primary cooling system of the core. Postulated Initiating Events (PIEs) in the HWS are evaluated for safety purposes. In the present study, transient thermal hydraulic analyses of HWS such as loss of heavy water flow owing to a pump failure, dilution of heavy water owing to a pipe rupture inside a pool, heavy water leakage owing to a pipe rupture outside a pool, and loss of heat removal owing to a secondary cooling system failure are analyzed

208

Hydraulic manipulator research at ORNL  

International Nuclear Information System (INIS)

Recently, task requirements have dictated that manipulator payload capacity increase to accommodate greater payloads, greater manipulator length, and larger environmental interaction forces. General tasks such as waste storage tank cleanup and facility dismantlement and decommissioning require manipulator life capacities in the range of hundreds of pounds rather than tens of pounds. To meet the increased payload capacities demanded by present-day tasks, manipulator designers have turned once again to hydraulics as a means of actuation. In order to successfully design, build, and deploy a new hydraulic manipulator (or subsystem), sophisticated modeling, analysis, and control experiments are usually needed. Oak Ridge National Laboratory (ORNL) has a history of projects that incorporate hydraulics technology, including mobile robots, teleoperated manipulators, and full-scale construction equipment. In addition, to support the development and deployment of new hydraulic manipulators, ORNL has outfitted a significant experimental laboratory and has developed the software capability for research into hydraulic manipulators, hydraulic actuators, hydraulic systems, modeling of hydraulic systems, and hydraulic controls. The purpose of this article is to describe the past hydraulic manipulator developments and current hydraulic manipulator research capabilities at ORNL. Included are example experimental results from ORNL's flexible/prismatic test stand

209

Hydraulic manipulator research at ORNL  

Energy Technology Data Exchange (ETDEWEB)

Recently, task requirements have dictated that manipulator payload capacity increase to accommodate greater payloads, greater manipulator length, and larger environmental interaction forces. General tasks such as waste storage tank cleanup and facility dismantlement and decommissioning require manipulator life capacities in the range of hundreds of pounds rather than tens of pounds. To meet the increased payload capacities demanded by present-day tasks, manipulator designers have turned once again to hydraulics as a means of actuation. In order to successfully design, build, and deploy a new hydraulic manipulator (or subsystem), sophisticated modeling, analysis, and control experiments are usually needed. Oak Ridge National Laboratory (ORNL) has a history of projects that incorporate hydraulics technology, including mobile robots, teleoperated manipulators, and full-scale construction equipment. In addition, to support the development and deployment of new hydraulic manipulators, ORNL has outfitted a significant experimental laboratory and has developed the software capability for research into hydraulic manipulators, hydraulic actuators, hydraulic systems, modeling of hydraulic systems, and hydraulic controls. The purpose of this article is to describe the past hydraulic manipulator developments and current hydraulic manipulator research capabilities at ORNL. Included are example experimental results from ORNL`s flexible/prismatic test stand.

Kress, R.L.; Jansen, J.F. [Oak Ridge National Lab., TN (United States); Love, L.J. [Oak Ridge Inst. for Science and Education, TN (United States)

1997-03-01

210

Hydraulic characteristics of an underdrained irrigation circle, Muskegon County wastewater disposal system, Michigan  

Science.gov (United States)

Muskegon County, Mich., disposes of wastewater by spray irrigating farmland on its waste-disposal site. Buried drains in the highly permeable unconfined aquifer at the site control the level of the water table. Hydraulic conductivity of the aquifer and drain leakance, the reciprocal of resistance to flow into the drains, was determined at a representative irrigation circle while calibrating a model of the ground-water flow system. Hydraulic conductivity is .00055 meter per second, in the north zone of the circle, and .00039 meter per second in the south zone. Drain leakance is low in both zones: 0.0000029 meter per second in the north and 0.0000095 meter per second in the south. Low drain leakance is responsible for waterlogging when irrigation rates are maintained at design levels. The capacity of the study circle to accept wastewater has been reduced by more than 35%. (USGS)

McDonald, M.G.

1980-01-01

211

Field investigation on consumer behavior and hydraulic performance of a district heating system in Tianjin, China  

Energy Technology Data Exchange (ETDEWEB)

With the implementation of heat reforms in China, the application of thermostatic radiator valves (TRVs) has been gaining popularity in the new-style district heating systems (DHSs). The objective of this study was to investigate consumer behavior (including regulation of TRVs and opening of windows) and its influences on the hydraulic performance and energy consumption of individuals and the whole system. The concurrence rate of individual behaviors and hydraulic interactions between individuals were analyzed. This study should be helpful to gain a comprehensive understanding of the new DHSs in China and consider a proper design/control strategy for these systems. Questionnaires and field observations of consumer behavior, tests of hydraulic performance, and surveys of energy consumption were carried out in a DHS in Tianjin, which was one of the heat metering and billing demonstration projects in China. The main results of the tests were as follows: water flow performance in apartment-level heating systems were diverse because consumers' behavior was varied and unpredictable, and the hydraulic interaction between consumers living along the line of a vertical pipe was obvious, and was stronger for terminal consumers with their TRVs set to higher values; however, flow variations in the whole DHS, which included 910 households, were relatively constant. A probability analysis was carried out to explain this phenomenon, and the conclusion was drawn that when there were more than 200 consumers, the stochastic consumer regulation behavior would bring less than 10% of total flow variations. Finally, the power consumption of the circulation pump, heat consumption and energy-saving potential of this type of DHS were discussed and some suggestions for TRV regulation and pump operation were made. (author)

Xu, Baoping; Fu, Lin; Di, Hongfa [Department of Building Science, Tsinghua University, Beijing 100084 (China)

2009-02-15

212

Experimental Study on Cartesian-Space PD Control for Hydraulic Manipulator  

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents Cartesian-space PD control of a hydraulic manipulator. The approach based upon “Virtual spring-damper hypothesis” is composed of virtual spring effects and virtual damper effects in task space. It has been applied to electrically driven robots. This experiment shows the comparison of Cartesian-space control with typical joint-space control in the performance of straight-line motion for the hydraulic manipulator that easily generate movements of manipulator without spending a huge amount of computational cost

Sang-Uk Chon

2014-08-01

213

Global asymptotic stabilization of large-scale hydraulic networks using positive proportional controls  

DEFF Research Database (Denmark)

An industrial case study involving a large-scale hydraulic network underlying a district heating system subject to structural changes is considered. The problem of controlling the pressure drop across the so-called end-user valves in the network to a designated vector of reference values under directional actuator constraints is addressed. The proposed solution consists of a set of decentralized positively constrained proportional control actions. The results show that the closed-loop system always has a globally asymptotically stable equilibrium point independently on the number of end-users. Furthermore, by a proper design of controller gains the closed-loop equilibrium point can be designed to belong to an arbitrarily small neighborhood of the desired equilibrium point. Since there exists a globally asymptotically stable equilibrium point independently on the number of end-users in the system, it is concluded that structural changes can be implemented without risk of introducing instability. In addition, structural changes can be easily implemented due to the decentralized control architecture.

Jensen, Tom NØrgaard; Wisniewski, Rafal

2014-01-01

214

Regulation and hydraulic design of highway stormwater drainage system  

OpenAIRE

The present work handles treatment of storm water from highways and its cleaning facilities hydraulic design according to Slovenian and German guidelines and directives. First part contains basic data that we have to take into consideration in order to achieve good hydraulic design for cleaning facilities. Road and highway categorization and their typical features in Slovenia and Germany are also written as basics for runoff hydraulic design. Following, most of the storm water cleaning facili...

Z?ibret, Marko

2006-01-01

215

Thermal hydraulic analysis of a passive residual heat removal system  

International Nuclear Information System (INIS)

A theoretical investigation on the thermal hydraulic characteristics of a new type of passive residual heat removal system (PRHRS) for an integrated pressurized water reactor is presented in this paper. The residual decay heat of the reactor core should be removed safely through multi-interknit natural circulation loops on the occasion of normal or accidental reactor shutdown. A one-dimensional model and a simulation code are developed to theoretically predict the transient behavior of the PRHRS. It is found that the calculated parameter (such as heat transfer capacity, pressure and mass flow rate) variation trends are reasonable. The decay heat can be safely removed by the PRHRS. However, the peak value of the secondary loop pressure is higher than the expected one. A protection measure of the secondary loop pressure should be considered in the model. (authors)

216

Second order sliding control with state dependent gain and its application to a hydraulic drive  

DEFF Research Database (Denmark)

The application of sliding modes for control of hydraulic drives appear promising due to strong robustness toward plant uncertainties and disturbances. Especially high order sliding modes may be successfully implemented avoiding the discontinuous control seen in first order sliding controls. However, the very feature of switching about the control target may be undesirable due to finite sampling time and actuator dynamics, and may cause oscillating flow line pressures. This paper discusses a second order sliding controller based on the so-called prescribed convergence algorithm, when used for chattering elimination in hydraulic drive control applications. For this usage the algorithm suffers from poor convergence properties unless a high control gain is chosen, which in turn increases pressure oscillations. To negotiate the combined challenge the controller is extended with a proportional term for improved convergence speed, and the gain of the discontinuous control is made variable according to the control target itself. It is shown that the control error and its derivative are globally convergent to a vicinity of the target via Lyapunov arguments, with accuracy dependent on control parameters, and finite time convergence properties are considered via homogeneity reasoning. Results demonstrate improved control operation compared to the basic algorithm when implemented for position tracking control of a hydraulic drive.

Schmidt, Lasse; Andersen, Torben Ole

2013-01-01

217

Active control system for high speed windmills  

Science.gov (United States)

A pump stroke is matched to the operating speed of a high speed windmill. The windmill drives a hydraulic pump for a control. Changes in speed of a wind driven shaft open supply and exhaust valves to opposite ends of a hydraulic actuator to lengthen and shorten an oscillating arm thereby lengthening and shortening the stroke of an output pump. Diminishing wind to a stall speed causes the valves to operate the hydraulic cylinder to shorten the oscillating arm to zero. A pressure accumulator in the hydraulic system provides the force necessary to supply the hydraulic fluid under pressure to drive the actuator into and out of the zero position in response to the windmill shaft speed approaching and exceeding windmill stall speed.

Avery, Don E. (45-437 Akimala St., Honolulu, HI 96744)

1988-01-01

218

COBRA-SFS, Thermal Hydraulics of Spent Fuel Storage System  

International Nuclear Information System (INIS)

1 - Description of program or function: COBRA-SFS is used for steady- state and transient thermal-hydraulic analysis of spent fuel storage systems as well as other heat transfer and fluid flow problems. It is designed to predict flow and temperature distributions under a wide range of flow conditions, including mixed and natural convection. Two auxiliary programs, RADX1 and RADGEN, generate blackbody view factors and calculate radiation exchange factors for unconsolidated spent fuel assemblies to be supplied as input to COBRA-SFS. 2 - Method of solution: The thermal-hydraulic analysis is separated into two parts - a flow field solution and an energy solution. COBRA-SFS solves a set of incompressible subchannel equations for mass and momentum conservation in the coolant and energy conservation in the fuel rods, solid structures, and coolant. The RECIRC solution method, a Newton-Raphson technique, is used to iteratively solve these equations. Radiation heat transfer between rod and slab surfaces is modeled using detailed radiation exchange factors, which are calculated from the geometry of the problem and the emissivities of the participating surfaces. The subchannel equations are fully implicit in time. 3 - Restrictions on the complexity of the problem - PARAMETER statements presently impose a maxima of: 50 channel gap connections, 40 channels, 20 fuel rods, 40 slab connections, 1 fuel types, 6 assemblies, 9 fuel rods interacting with a channel, 6 fuel nodes per fuel rng with a channel, 6 fuel nodes per fuel rod, 4 axial fuel type divisions. By modifying PARAMETER statements, code dimensioning limits can be changed to fit any given problem, limited only by available storage

219

Lead coolant test facility systems design, thermal hydraulic analysis and cost estimate  

Energy Technology Data Exchange (ETDEWEB)

The Idaho National Laboratory prepared a preliminary technical and functional requirements (T and FR), thermal hydraulic design and cost estimate for a lead coolant test facility. The purpose of this small scale facility is to simulate lead coolant fast reactor (LFR) coolant flow in an open lattice geometry core using seven electrical rods and liquid lead or lead-bismuth eutectic coolant. Based on review of current world lead or lead-bismuth test facilities and research needs listed in the Generation IV Roadmap, five broad areas of requirements were identified as listed below: Bullet Develop and demonstrate feasibility of submerged heat exchanger. Bullet Develop and demonstrate open-lattice flow in electrically heated core. Bullet Develop and demonstrate chemistry control. Bullet Demonstrate safe operation. Bullet Provision for future testing. This paper discusses the preliminary design of systems, thermal hydraulic analysis, and simplified cost estimated. The facility thermal hydraulic design is based on the maximum simulated core power using seven electrical heater rods of 420 kW; average linear heat generation rate of 300 W/cm. The core inlet temperature for liquid lead or Pb/Bi eutectic is 4200 Degree-Sign C. The design includes approximately seventy-five data measurements such as pressure, temperature, and flow rates. The preliminary estimated cost of construction of the facility is $3.7M (in 2006 $). It is also estimated that the facility will require two years to be constructed and ready for operation.

Khericha, Soli, E-mail: slk2@inel.gov [Battelle Energy Alliance, LLC, Idaho National Laboratory, Idaho Falls, ID 83415 (United States); Harvego, Edwin; Svoboda, John; Evans, Robert [Battelle Energy Alliance, LLC, Idaho National Laboratory, Idaho Falls, ID 83415 (United States); Dalling, Ryan [ExxonMobil Gas and Power Marketing, Houston, TX 77069 (United States)

2012-01-15

220

Lead Coolant Test Facility Systems Design, Thermal Hydraulic Analysis and Cost Estimate  

Energy Technology Data Exchange (ETDEWEB)

The Idaho National Laboratory prepared a preliminary technical and functional requirements (T&FR), thermal hydraulic design and cost estimate for a lead coolant test facility. The purpose of this small scale facility is to simulate lead coolant fast reactor (LFR) coolant flow in an open lattice geometry core using seven electrical rods and liquid lead or lead-bismuth eutectic coolant. Based on review of current world lead or lead-bismuth test facilities and research needs listed in the Generation IV Roadmap, five broad areas of requirements were identified as listed: (1) Develop and Demonstrate Feasibility of Submerged Heat Exchanger; (2) Develop and Demonstrate Open-lattice Flow in Electrically Heated Core; (3) Develop and Demonstrate Chemistry Control; (4) Demonstrate Safe Operation; and (5) Provision for Future Testing. This paper discusses the preliminary design of systems, thermal hydraulic analysis, and simplified cost estimate. The facility thermal hydraulic design is based on the maximum simulated core power using seven electrical heater rods of 420 kW; average linear heat generation rate of 300 W/cm. The core inlet temperature for liquid lead or Pb/Bi eutectic is 4200 C. The design includes approximately seventy-five data measurements such as pressure, temperature, and flow rates. The preliminary estimated cost of construction of the facility is $3.7M (in 2006 $). It is also estimated that the facility will require two years to be constructed and ready for operation.

Soli Khericha; Edwin Harvego; John Svoboda; Ryan Dalling

2012-01-01

221

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

Science.gov (United States)

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

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

2014-12-01

222

Thermal hydraulics and mechanics research on fusion blanket system  

International Nuclear Information System (INIS)

In-vessel components such as Blanket and Divertor in a fusion reactor have a function of exhausting high heat and particle loads in order to maintain the structural soundness of the reactor. In the International Thermonuclear Experimental Reactor called ITER, build by ITER Organization under the framework of collaboration of seven parties including Japan, there are two kinds of blanket systems will be install. One is a shield blanket, which consists of a first wall (FW) and a block module shielding against neutron flux to a vacuum chamber and a superconducting magnet system. The other blanket system is called as a Test Blanket Module (TBM). TBM is a kind of prototype blanket for a fusion power plant and has functions of breeding of tritium (T) and extraction of energy from fusion plasma. TBM consists of FW and T-breeding / neutron (n)-multiplier zone. A concept of TBM developed by JAEA is water-cooled pebble-bed type, which means that FW and other structures are cooled by pressurized high temperature water and T-breeding / n-multiplier zone consists of multiple layers of pebble bed made of T-breeding and n-multiplier material. This paper describes the status of R and Ds on FW and pebble beds from the view of thermo-hydraulics and mechanics. (author)

223

Development of an Advanced Hydraulic Fracture Mapping System  

Energy Technology Data Exchange (ETDEWEB)

The project to develop an advanced hydraulic fracture mapping system consisted of both hardware and analysis components in an effort to build, field, and analyze combined data from tiltmeter and microseismic arrays. The hardware sections of the project included: (1) the building of new tiltmeter housings with feedthroughs for use in conjunction with a microseismic array, (2) the development of a means to use separate telemetry systems for the tilt and microseismic arrays, and (3) the selection and fabrication of an accelerometer sensor system to improve signal-to-noise ratios. The analysis sections of the project included a joint inversion for analysis and interpretation of combined tiltmeter and microseismic data and improved methods for extracting slippage planes and other reservoir information from the microseisms. In addition, testing was performed at various steps in the process to assess the data quality and problems/issues that arose during various parts of the project. A prototype array was successfully tested and a full array is now being fabricated for industrial use.

Norm Warpinski; Steve Wolhart; Larry Griffin; Eric Davis

2007-01-31

224

Development of a thermal-hydraulics experimental system for high Tc superconductors cooled by liquid hydrogen  

International Nuclear Information System (INIS)

A thermal-hydraulics experimental system of liquid hydrogen was developed in order to investigate the forced flow heat transfer characteristics in the various cooling channels for wide ranges of subcoolings, flow velocities, and pressures up to supercritical. A main tank is connected to a sub tank through a hydrogen transfer line with a control valve. A channel heater is located at one end of the transfer line in the main tank. Forced flow through the channel is produced by adjusting the pressure difference between the tanks and the valve opening. The mass flow rate is measured from the weight change of the main tank. For the explosion protection, electrical equipments are covered with a nitrogen gas blanket layer and a remote control system was established. The first cryogenic performance tests confirmed that the experimental system had satisfied with the required performances. The forced convection heat transfer characteristics was successfully measured at the pressure of 0.7 MPa for various flow velocities.

225

Monitoring and control of the hydraulic fluid for economical use of shield supports; Ueberwachung und Steuerung der Hydraulikfluessigkeit fuer den wirtschaftlichen Einsatz von Schildausbau  

Energy Technology Data Exchange (ETDEWEB)

For fire protection reasons shield supports in the coal mining industry are operated with water as hydraulic fluid, to which 1.5 to 3% HFA concentrate must be added according to the corrosive property of the water to ensure protection against corrosion, lubrication properties and biostability in the entire hydraulic system. Permanent monitoring of the hydraulic fluid used is necessary to achieve maximum life and low repair costs of the hydraulic components. The hitherto customary monitoring by manual refractometer measurements at the face will no longer be suitable for the economic importance of powered supports. About 25% of the repair costs can be saved by an HFA fluid with an optimum formulation by reducing the damage caused by corrosion. A process refractometer for online measurement and control of the HFA concentration, which has proved its suitability for the mining industry in a trial at the West colliery of DSK, has been developed for the latter. (orig.)

Langefeld, O. [Abt. fuer Maschinelle Betriebsmittel in Bergbau und Geotechnik des Inst. fuer Bergbau, TU Clausthal, Clausthal-Zeilerfeld (Germany); Mozar, A. [Deutsche Steinkohle AG (DSK), Herne (Germany). HFA-Onlinemessung im Servicebereich Technik; Hunfeld, H.H.

2006-05-29

226

Thermal-Hydraulic Analysis Tasks for ANAV NPPs in Support of Plant Operation and Control  

OpenAIRE

Thermal-hydraulic analysis tasks aimed at supporting plant operation and control of nuclear power plants are an important issue for the Asociación Nuclear Ascó-Vandellòs (ANAV). ANAV is the consortium that runs the Ascó power plants (2 units) and the Vandellòs-II power plant. The reactors are Westinghouse-design, 3-loop PWRs with an approximate electrical power of 1000 MW. The Technical University of Catalonia (UPC) thermal-hydraulic analysis te...

Batet, L.; F. Reventós; Llopis, C.; Sol, I.; Pretel, C.

2008-01-01

227

High Bulk Modulus of Ionic Liquid and Effects on Performance of Hydraulic System  

Science.gov (United States)

Over recent years ionic liquids have gained in importance, causing a growing number of scientists and engineers to investigate possible applications for these liquids because of their unique physical and chemical properties. Their outstanding advantages such as nonflammable liquid within a broad liquid range, high thermal, mechanical, and chemical stabilities, low solubility for gases, attractive tribological properties (lubrication), and very low compressibility, and so forth, make them more interesting for applications in mechanical engineering, offering great potential for new innovative processes, and also as a novel hydraulic fluid. This paper focuses on the outstanding compressibility properties of ionic liquid EMIM-EtSO4, a very important physical chemically property when IL is used as a hydraulic fluid. This very low compressibility (respectively, very high Bulk modulus), compared to the classical hydraulic mineral oils or the non-flammable HFDU type of hydraulic fluids, opens up new possibilities regarding its usage within hydraulic systems with increased dynamics, respectively, systems' dynamic responses. PMID:24526900

Kalb, Roland; Tasner, Tadej

2014-01-01

228

Global stabilization of large-scale hydraulic networks with quantized and positive proportional controls  

DEFF Research Database (Denmark)

The problem considered here is output regulation of a large-scale hydraulic network where the structure of the network is subject to change and where the actuation is subject to a non-negativity constraint. Previous results have shown that semi-global practical output regulation is achievable using a set of decentralised, logarithmic quantised and constrained control actions with properly designed quantisation parameters. That is, an attractor set with a compact basin of attraction exists. Subsequently, the basin can be increased by increasing the control gains. In our work, this result is extended by showing that an attractor set with a global basin of attraction exists for arbitrary values of positive control gains, given that the upper level of the quantiser is properly designed. Furthermore, the proof is given for general monotone quantisation maps. Since the basin of attraction is global and the result is independent on the size of the network, this shows that structural changes can be implemented without destabilising the closed-loop system.

Jensen, Tom NØrgaard; Wisniewski, Rafal

2013-01-01

229

Hydraulic performance analysis of a multiple injection extraction well system  

Science.gov (United States)

SummaryInvestigating the hydraulic performance of the flow field created by a multiple injection-extraction well system for groundwater remediation requires the design of novel strategies for tracer testing and efficient modeling. In this work, we report on tracer tests conducted in a well system comprising two injection and two extraction wells designed for an in situ bioremediation of uranium at Oak Ridge, TN, about 2 years after the start of operation. The domain of the flow field can be divided into an inner cell, an outer cell, and transition zones. To characterize advective-dispersive transport, two tracer tests were performed with the injection of bromide solution. The system was operated as during groundwater remediation, and the tracer was partially recirculated. Breakthrough curves (BTCs) were measured in the extraction wells and the multi-level sampling (MLS) ports. The methods of transfer function and temporal moments were implemented to analyze the BTCs. By jointly evaluating the temporal moments of the BTCs in the extraction wells, we can conveniently estimate the recirculating flow fractions in different zones. This approach does not require the detailed characterization of the flow field. The parameters of transfer functions fitted at the MLS wells indicate the flow field may have changed over the tracer test period. This observation indicates that bioremediation influences the flow field even when the well pumping rates are kept constant, which suggests that aquifer characterization may need to be repeated during bioremediation. The methods of transfer functions and temporal moments with tracer tests are flexible, economical, and well-suited to evaluate the performance of the system during long periods of remediation.

Luo, Jian; Wu, Wei-Min; Carley, Jack; Ruan, Chuanmin; Gu, Baohua; Jardine, Phillip M.; Criddle, Craig S.; Kitanidis, Peter K.

2007-04-01

230

The SNS Resonance Control Cooling System Control Valve Upgrade Performance  

International Nuclear Information System (INIS)

The normal-conducting linac of the Spallation Neutron Source (SNS) uses 10 separate Resonance Control Cooling System (RCCS) water skids to control the resonance of 6 Drift Tube Linac (DTL) and 4 Coupled Cavity Linac (CCL) accelerating structures. The RCCS water skids use 2 control valves; one to regulate the chilled water flow and the other to bypass water to a chilled water heat exchanger. These valves have hydraulic actuators that provide position and feedback to the control system. Frequency oscillations occur using these hydraulic actuators due to their coarse movement and control of the valves. New pneumatic actuator and control positioners have been installed on the DTL3 RCCS water skid to give finer control and regulation of DTL3 cavity temperature. This paper shows a comparison of resonance control performance for the two valve configurations.

231

Engineered Barrier System Thermal-Hydraulic-Chemical Column Test Report  

International Nuclear Information System (INIS)

The Engineered Barrier System (EBS) Thermal-Hydraulic-Chemical (THC) Column Tests provide data needed for model validation. The EBS Degradation, Flow, and Transport Process Modeling Report (PMR) will be based on supporting models for in-drift THC coupled processes, and the in-drift physical and chemical environment. These models describe the complex chemical interaction of EBS materials, including granular materials, with the thermal and hydrologic conditions that will be present in the repository emplacement drifts. Of particular interest are the coupled processes that result in mineral and salt dissolution/precipitation in the EBS environment. Test data are needed for thermal, hydrologic, and geochemical model validation and to support selection of introduced materials (CRWMS M and O 1999c). These column tests evaluated granular crushed tuff as potential invert ballast or backfill material, under accelerated thermal and hydrologic environments. The objectives of the THC column testing are to: (1) Characterize THC coupled processes that could affect performance of EBS components, particularly the magnitude of permeability reduction (increases or decreases), the nature of minerals produced, and chemical fractionation (i.e., concentrative separation of salts and minerals due to boiling-point elevation). (2) Generate data for validating THC predictive models that will support the EBS Degradation, Flow, and Transport PMR, Rev. 01

232

Characterization of Hydraulically Significant Discontinuities in Mudrocks at the Waste Control Specialists (WCS) Site, West Texas  

Science.gov (United States)

Triassic mudrocks of the Dockum Group (Cooper Canyon Formation) host four, below-grade landfills at the Waste Control Specialists (WSC) site in Andrews County, Texas, including: a hazardous waste landfill and three radioactive waste landfills. At many radioactive waste disposal facilities, the long-term performance of the facility may be influenced by the transport of radionuclides through interconnected fracture networks. WCS developed an integrated geologic mapping and hydraulic testing program to evaluate the hydraulic significance of discontinuities within Dockum rocks. At the WCS site, the Dockum consists of mudrocks with sparse siltstone/sandstone interbeds that developed in a semi-arid environment from an ephemeral meandering fluvial system. Sedimentary studies reveal that the mudrocks are ancient floodplain vertisols (soils with swelling clays) and siltstone/sandstone interbeds are fluvial channel deposits that were frequently subaerially exposed. Rock discontinuities, including fractures, were mapped during the excavation of the WCS radioactive waste landfills along vertical faces prepared by the construction contractor. Face locations were selected to insure nearly complete vertical coverage for each landfill. Individual discontinuities were mapped and their strike, dip, length, roughness, curvature, staining, and evidence of displacement were described. In the three radioactive waste disposal landfills, over 1750 discontinuities across 35 excavated faces were mapped and described, where each face was nominally 8 to 10 ft tall and 50 to 100 ft long. On average, the orientation of the discontinuities was horizontal, and no other significant trends were observed. Mapping within the landfill excavations shows that most discontinuities within Dockum rocks are horizontal, concave upward, slickensided surfaces that developed in the depositional environment, as repeated wetting and drying cycles led to shrinking and swelling of floodplain vertisols. Fractures that showed staining (a possible indicator of past or present hydraulic activity) are rare, vertical to near-vertical, and occur mainly in, and adjacent to, mechanically stiff siltstone and sandstone interbeds. No interconnected fracture networks were observed. A series of pressurized air tests were conducted to evaluate fracture interconnectivity at and below the landfill facilities. Three pairs of vertical and three pairs of inclined boreholes were tested at depths ranging from 40 to 215 feet below ground surface. Borehole packers and volume-displacement tools were placed in each borehole to isolate the injection and observation horizons and minimize borehole storage effects, respectively. Injection pressures ranged from 1 to 5 psig. Pressures within the injection boreholes quickly stabilized and slowly decayed due to porous media flow, while no pressure changes occurred in the observation boreholes. These tests confirm the absence of hydrologically significant fracture networks in the subsurface at the WCS site.

Kuszmaul, J. S.; Holt, R. M.; Powers, D. W.; Beauheim, R.; Pickens, J. F.; grisak, G. E.; Hughes, E.; Cook, S.

2011-12-01

233

Research on the improvement of nuclear safety -Thermal hydraulic tests for reactor safety system-  

International Nuclear Information System (INIS)

The present research aims at the development of the thermal hydraulic verification test technology for the safety system of the conventional and advanced nuclear power plant and the development of the advanced thermal hydraulic measuring techniques. In this research, test facilities simulating the primary coolant system and safety system are being constructed for the design verification tests of the existing and advanced nuclear power plant. 97 figs, 14 tabs, 65 refs. (Author)

234

Macrocalibration in the process of hydraulic modelling of water supply systems  

OpenAIRE

The thesis presents an integrated approach to hydraulic modelling of water supply systems, which is mostly based on our own research. The starting phase of hydraulic modelling requires appropriate setting up of a geographic information system and preparation of databases of all entities. This is today crucial for efficient management of water supply systems as far as technical as well as economic and legal aspects are concerned. Appropriate management of data on a water supply ...

S?antl, Sas?o

2007-01-01

235

Studies on the performance of the hydraulic control rod drive for the NHR-200  

International Nuclear Information System (INIS)

Theoretical analysis and experimental study on the steady state property of the hydraulic control rod drive mechanism for the 200 MW nuclear heating reactor have been carried out in depth. The minimum and maximum holding flow in steady state and their changes along with temperature were identified, and the relationship between the steady state property and the design data of the control rod drive mechanism was analyzed too. A fine agreement between the analysis results and measured data has been achieved. (orig.)

236

Modeling and Fuzzy Adaptive PID Control of a New Hydraulic Erecting Mechanism  

Directory of Open Access Journals (Sweden)

Full Text Available To overcome the nonlinearity and solve the cooperation problem between erect cylinder and horizontal cylinder of a new hydraulic erecting mechanism, the combined simulation model is built based on AMESim/Simulink.The best cooperation time bteween erect cylinder and horizontal cylinder is confirmed. Further, the fuzzy adaptive PID controller is introduced to improve the control performance aiming to nonlinearity exist in the erecting mechanism.

Jian Xie

2013-11-01

237

Thermal hydraulic performance of naturally aspirated control rod housing assemblies  

International Nuclear Information System (INIS)

Savannah River Site reactors are comprised of heat generating fuel/target assemblies, control rods which regulate reactor power, and heavy water which acts as the coolant and as a moderator. The fuel/target assemblies are cooled by the downflow of heavy water while the control rods are cooled via upflow. Five control rods are grouped with two safety rods in seven-channel assemblies called septifoils. Under normal operating conditions, the reactor power level, radial shape flux and axial power flux are regulated by the positioning of the control rods. The control rods are solid rods of a lithium-aluminum alloy with an thin aluminum outer sheath. Lithium is a good absorber of neutrons and, thus control rod temperatures rise with reactor power. At conditions of sufficiently high reactor power and degraded coolant flow, the control rods could heat sufficiently to cause a metallurigical failure of the sheath leading to molten material coming in contact with water and the possibility of a steam explosion. An accident has been postulated as part of the analysis involving the safety upgrade of Savannah River Site reactors in which the housing is not seated on the pin. Coolant from the upflow pin would not be directed into the housing but, into the moderator space surrounding the housing. Only naturally aspirated cooling due to buoyancy effects would be available to cool the control rods and the coolant mass flow rate would drop significantly from its nominal value. In this study, the mechanisms and limits of cooling heated rods housed in an unseated septifoil are addressed. Experiments were conducted on a shortened, prototypic housing with electrically heated rods to gain an understanding of the phenomena governing the cooling in such a case and develop data which can be used to evaluate predictive models. These experiments are described, their results discussed, and the predictions of current models is presented

238

Thermal-Hydraulic Experiments and Modelling for Advanced Nuclear Reactor Systems  

International Nuclear Information System (INIS)

The objectives of the project are to study thermal hydraulic characteristics of reactor primary system for the verification of the reactor safety and to evaluate new safety concepts of new safety design features. To meet the research goal, several thermal hydraulic experiments were performed and related thermal hydraulic models were developed with the experimental data which were produced through the thermal hydraulic experiments. Followings are main research topics; - Multi-dimensional Phenomena in a Reactor Vessel Downcomer - Condensation Load and Thermal Mixing in the IRWST - Development of Thermal-Hydraulic Models for Two-Phase Flow - Development of Measurement Techniques for Two-Phase Flow - Supercritical Reactor T/H Characteristics Analysis From the above experimental and analytical studies, new safety design features of the advanced power reactors were verified and lots of the safety issues were also resolved

239

Thermal-Hydraulic Experiments and Modelling for Advanced Nuclear Reactor Systems  

Energy Technology Data Exchange (ETDEWEB)

The objectives of the project are to study thermal hydraulic characteristics of reactor primary system for the verification of the reactor safety and to evaluate new safety concepts of new safety design features. To meet the research goal, several thermal hydraulic experiments were performed and related thermal hydraulic models were developed with the experimental data which were produced through the thermal hydraulic experiments. Followings are main research topics; - Multi-dimensional Phenomena in a Reactor Vessel Downcomer - Condensation Load and Thermal Mixing in the IRWST - Development of Thermal-Hydraulic Models for Two-Phase Flow - Development of Measurement Techniques for Two-Phase Flow - Supercritical Reactor T/H Characteristics Analysis From the above experimental and analytical studies, new safety design features of the advanced power reactors were verified and lots of the safety issues were also resolved.

Song, C. H.; Chung, M. K.; Park, C. K. and others

2005-04-15

240

Hydraulic Car  

Science.gov (United States)

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

Workshop, Watsonville E.

2011-01-01

241

Hydraulic turbines  

International Nuclear Information System (INIS)

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

242

French code system for a sodium cooled LMR inter-assembly thermal hydraulic analysis  

International Nuclear Information System (INIS)

Sodium cooled LMR core is generally comprised of many ducted assemblies which have no flow exchanges between them. So, the required flow to each assembly corresponding to its power has to be allocated in thermal hydraulic design. Flow allocation facility, which is called orifice, is used for this purpose in an LMR core. In this context, flow grouping, assembly subchannel analysis and inter-assembly flow analysis have to be done in the LMR core thermal hydraulic design and analysis. This report describes this sodium cooled LMR core thermal hydraulic design procedure, in which are flow grouping, subchannel analysis and inter-assembly whole core analysis. And the French whole core analysis code system is described which is used for the domestic whole core thermal hydraulic analysis code system development. Firstly, sodium cooled LMR core thermal hydraulic conceptual design and analysis procedure is explained in chapter 2. Chapter 3 overviews the necessity and methodology of the whole core thermal hydraulic analysis, and the French whole core analysis system is described in chapter 4. Chapter 5 describes the domestic plan of the inter-assembly thermal hydraulic analysis system, and chapter 6 shows the conclusion and the future works

243

OPERATIONAL FAULT DIAGNOSIS IN INDUSTRIAL HYDRAULIC SYSTEMS THROUGH MODELING THE INTERNAL LEAKAGE OF ITS COMPONENTS  

OpenAIRE

In this study, a model of a high pressure hydraulic system was developed using the bond graph method to investigate the effect of the internal leakage of its main components (pump, cylinder and 4/2 way valve) on the operational characteristics of the system under various loads. All the main aspects of the hydraulic circuit (like the internal leakages, the compressibility of the fluid, the hydraulic pressure drop, the inertia of moving masses and the friction of the spool) were taken into cons...

Athanasatos, P.; Koulocheris, D.; Costopoulos, T.; Raptis, K.

2013-01-01

244

Effects by sea wave on thermal hydraulics of marine reactor system  

International Nuclear Information System (INIS)

This paper describes the experiments of the first Japanese nuclear ship 'Mutsu', to investigate the effects of sea wave on the thermal hydraulics of marine reactor system while cruising through various sea conditions. The experimental data were analyzed in time-domain by RETRAN-02/GRAV code. This code was modified so as to simulate the ship motion effect on reactor thermal hydraulics. The data were also analyzed in frequency domain by Blackman-Turkey method for the calculation of the spectrum and response function. The experiments involving ship maneuvering were performed by cruising on different wave heights, as well as wave directions in the northern Pacific ocean. From the experiments, vertical acceleration due to ship motion was found to induce direct variation of water levels in the SGs and the pressurizer. The water level variations were largest in the head wave, but smallest in the following wave. On the other hand, the following wave caused greater variation of the reactor power when the feed back control for the shaft revolution speed was used. Mechanism of response of water levels and reactor power with respect to the external forces are discussed. The response function (gain or phase shift) of reactor power to steam flow variation by the wave during cruising at rough sea condition was found to be roughly that without the work of control rod. (author)

245

Effects by sea wave on thermal hydraulics of marine reactor system  

Energy Technology Data Exchange (ETDEWEB)

This paper describes the experiments of the first Japanese nuclear ship `Mutsu`, to investigate the effects of sea wave on the thermal hydraulics of marine reactor system while cruising through various sea conditions. The experimental data were analyzed in time-domain by RETRAN-02/GRAV code. This code was modified so as to simulate the ship motion effect on reactor thermal hydraulics. The data were also analyzed in frequency domain by Blackman-Turkey method for the calculation of the spectrum and response function. The experiments involving ship maneuvering were performed by cruising on different wave heights, as well as wave directions in the northern Pacific ocean. From the experiments, vertical acceleration due to ship motion was found to induce direct variation of water levels in the SGs and the pressurizer. The water level variations were largest in the head wave, but smallest in the following wave. On the other hand, the following wave caused greater variation of the reactor power when the feed back control for the shaft revolution speed was used. Mechanism of response of water levels and reactor power with respect to the external forces are discussed. The response function (gain or phase shift) of reactor power to steam flow variation by the wave during cruising at rough sea condition was found to be roughly that without the work of control rod. (author).

Ishida, Toshihisa; Kusunoki, Tsuyoshi; Ochiai, Masaaki [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Yao, Toshiaki; Inoue, Kimio

1995-08-01

246

Visual and intelligent transients and accidents analyzer based on thermal-hydraulic system code  

International Nuclear Information System (INIS)

Full text of publication follows: Many thermal-hydraulic system codes were developed in the past twenty years, such as RELAP5, RETRAN, ATHLET, etc. Because of their general and advanced features in thermal-hydraulic computation, they are widely used in the world to analyze transients and accidents. But there are following disadvantages for most of these original thermal-hydraulic system codes. Firstly, because models are built through input decks, so the input files are complex and non-figurative, and the style of input decks is various for different users and models. Secondly, results are shown in off-line data file form. It is not convenient for analysts who may pay more attention to dynamic parameters trend and changing. Thirdly, there are few interfaces with other program in these original thermal-hydraulic system codes. This restricts the codes expanding. The subject of this paper is to develop a powerful analyzer based on these thermal-hydraulic system codes to analyze transients and accidents more simply, accurately and fleetly. Firstly, modeling is visual and intelligent. Users build the thermalhydraulic system model using component objects according to their needs, and it is not necessary for them to face bald input decks. The style of input decks created automatically by the analyzer is unified and can be accepted easily by other people. Secondly, parameters concerned by analyst can be dynamically communicated to show or even change. Thirdly, the analyzer prw or even change. Thirdly, the analyzer provide interface with other programs for the thermal-hydraulic system code. Thus parallel computation between thermal-hydraulic system code and other programs become possible. In conclusion, through visual and intelligent method, the analyzer based on general and advanced thermal-hydraulic system codes can be used to analysis transients and accidents more effectively. The main purpose of this paper is to present developmental activities, assessment and application results of the visual and intelligent analyzer. (authors)

247

Fault Diagnosis for Nonlinear Hydraulic-Mechanical Drilling Pipe Handling System  

OpenAIRE

Leakage and increased friction are common faults in hydraulic cylinders that can have serious consequences if they are not detected at early stage. In this paper, the design of a fault detector for a nonlinear hydraulic mechanical system is presented. By considering the system in steady state, two residual signals are generated and analysed with a composite hypothesis test which accommodates for unknown parameters. The resulting detector is able to detect abrupt changes i...

Choux, Martin; Blanke, Mogens

2011-01-01

248

Main lines of the development of electrohydraulic control systems for steam turbines produced by OAO turboatom  

Science.gov (United States)

Different design versions of the hydraulic part of electrohydraulic steam turbine control systems are considered. Their advantages and shortcomings are shown, and recommendations for their application are formulated.

Burakov, A. S.; Rokhlenko, V. Yu.; Shvetsov, V. L.

2010-02-01

249

Multi-parameter monitoring system for hydraulic fluids; Multi-Parameter Monitoring System fuer Hydraulische Fluessigkeiten  

Energy Technology Data Exchange (ETDEWEB)

A miniaturised sensor system for aviation hydraulic fluids is presented. The system consists of an optochemical sensor and a particle sensor. The optochemical sensor detects the form of the O-H absorption feature around 3500 cm{sup -1} to reveal the water and acid contamination in the fluid. The particle sensor uses a light barrier principle to derive its particle contamination number. (orig.)

Paul, Sumit; Legner, Wolfgang; Hackner, Angelika; Mueller, Gerhard [EADS Innovation Works, Muenchen (Germany). Bereich Sensors, Electronics and Systems Integration; Baumbach, Volker [Airbus Operations GmbH, Bremen (Germany). Bereich Hydraulic Performance and Integrity

2011-07-01

250

46 CFR 58.30-10 - Hydraulic fluid.  

Science.gov (United States)

...2010-10-01 2010-10-01 false Hydraulic fluid. 58.30-10 Section 58...and Control Systems § 58.30-10 Hydraulic fluid. (a) The requirements...inspection. (b) The fluid used in hydraulic power transmission systems shall...

2010-10-01

251

Proceedings of the 1991 national conference on hydraulic engineering  

International Nuclear Information System (INIS)

This book contains the proceedings of the 1991 National Conference of Hydraulic Engineering. The conference was held in conjunction with the International Symposium on Ground Water and a Software Exchange that facilitated exchange of information on recent software developments of interest to hydraulic engineers. Also included in the program were three mini-symposia on the Exclusive Economic Zone, Data Acquisition, and Appropriate Technology. Topics include sedimentation; appropriate technology; exclusive economic zone hydraulics; hydraulic data acquisition and display; innovative hydraulic structures and water quality applications of hydraulic research, including the hydraulics of aerating turbines; wetlands; hydraulic and hydrologic extremes; highway drainage; overtopping protection of dams; spillway design; coastal and estuarine hydraulics; scale models; computation hydraulics; GIS and expert system applications; watershed response to rainfall; probabilistic approaches; and flood control investigations

252

Thermal-hydraulic characteristics of a combustion engineering system 80 steam generator. Volume 2. Appendix A  

International Nuclear Information System (INIS)

The Comparative Thermal-Hydraulic Evaluation of Steam Generators program represents an analytical investigation of the thermal-hydraulic characteristics of four PWR steam generators. The analytical tool utilized in this investigation is the CALIPSOS code, a three-dimensional flow distribution code. This report presents the steady state thermal-hydraulic characteristics on the secondary side of a Combustion Engineering System 80 steam generator. Details of the CALIPSOS model with accompanying assumptions, operating parameters, and transport correlations are identified. Comprehensive graphical and numerical results are presented to facilitate the desired comparison with other steam generators analyzed by the same flow distribution code

253

Discrete Displacement Hydraulic Power Take-Off System for the Wavestar Wave Energy Converter  

Directory of Open Access Journals (Sweden)

Full Text Available The Wavestar Wave Energy Converter (WEC is a multiple absorber concept, consisting of 20 hemisphere shaped floats attached to a single platform. The heart of the Wavestar WEC is the Power Take-Off (PTO system, converting the wave induced motion of the floats into a steady power output to the grid. In the present work, a PTO based on a novel discrete displacement fluid power technology is explored for the Wavestar WEC. Absorption of power from the floats is performed by hydraulic cylinders, supplying power to a common fixed pressure system with accumulators for energy smoothing. The stored pressure energy is converted into electricity at a steady pace by hydraulic motors and generators. The storage, thereby, decouples the complicated process of wave power absorption from power generation. The core for enabling this PTO technology is implementing a near loss-free force control of the energy absorbing cylinders. This is achieved by using special multi-chambered cylinders, where the different chambers may be connected to the available system pressures using fast on/off valves. Resultantly, a Discrete Displacement Cylinder (DDC is created, allowing near loss free discrete force control. This paper presents a complete PTO system for a 20 float Wavestar based on the DDC. The WEC and PTO is rigorously modeled from incident waves to the electric output to the grid. The resulting model of +600 states is simulated in different irregular seas, showing that power conversion efficiencies above 70% from input power to electrical power is achievable for all relevant sea conditions.

Enrique Vidal

2013-08-01

254

Discrete Displacement Hydraulic Power Take-Off System for the Wavestar Wave Energy Converter  

DEFF Research Database (Denmark)

The Wavestar Wave Energy Converter (WEC) is a multiple absorber concept, consisting of 20 hemisphere shaped floats attached to a single platform. The heart of the Wavestar WEC is the Power Take-Off (PTO) system, converting the wave induced motion of the floats into a steady power output to the grid. In the present work, a PTO based on a novel discrete displacement fluid power technology is explored for the Wavestar WEC. Absorption of power from the floats is performed by hydraulic cylinders, supplying power to a common fixed pressure system with accumulators for energy smoothing. The stored pressure energy is converted into electricity at a steady pace by hydraulic motors and generators. The storage, thereby, decouples the complicated process of wave power absorption from power generation. The core for enabling this PTO technology is implementing a near loss-free force control of the energy absorbing cylinders. This is achieved by using special multi-chambered cylinders, where the different chambers may be connected to the available system pressures using fast on/off valves. Resultantly, a Discrete Displacement Cylinder (DDC) is created, allowing near loss free discrete force control. This paper presents a complete PTO system for a 20 float Wavestar based on the DDC. The WEC and PTO is rigorously modeled from incident waves to the electric output to the grid. The resulting model of +600 states is simulated in different irregular seas, showing that power conversion efficiencies above 70% from input power to electrical power is achievable for all relevant sea conditions.

Hansen, Rico Hjerm; Kramer, Morten

2013-01-01

255

Application of flow network models of SINDA/FLUINT{sup TM} to a nuclear power plant system thermal hydraulic code  

Energy Technology Data Exchange (ETDEWEB)

In order to enhance the dynamic and interactive simulation capability of a system thermal hydraulic code for nuclear power plant, applicability of flow network models in SINDA/FLUINT{sup TM} has been tested by modeling feedwater system and coupling to DSNP which is one of a system thermal hydraulic simulation code for a pressurized heavy water reactor. The feedwater system is selected since it is one of the most important balance of plant systems with a potential to greatly affect the behavior of nuclear steam supply system. The flow network model of this feedwater system consists of condenser, condensate pumps, low and high pressure heaters, deaerator, feedwater pumps, and control valves. This complicated flow network is modeled and coupled to DSNP and it is tested for several normal and abnormal transient conditions such turbine load maneuvering, turbine trip, and loss of class IV power. The results show reasonable behavior of the coupled code and also gives a good dynamic and interactive simulation capabilities for the several mild transient conditions. It has been found that coupling system thermal hydraulic code with a flow network code is a proper way of upgrading simulation capability of DSNP to mature nuclear plant analyzer (NPA). 5 refs., 10 figs. (Author)

Chung, Ji Bum [Institute for Advanced Engineering, Yongin (Korea, Republic of); Park, Jong Woon [Korea Electric Power Research Institute, Taejon (Korea, Republic of)

1998-12-31

256

Hydraulic modeling of a mixed water level control hydro-mechanical gate  

OpenAIRE

This article describes the hydraulic behavior of a mixed water level control hydromechanical gate present in several irrigation canals. The automatic gate is termed "mixed" because it can hold either the upstream water level or the downstream water level constant according to the flow conditions. Such a complex behavior is obtained through a series of side tanks linked by orifices and weirs. No energy supply is needed in this regulation process. The mixed flow gate is analyzed and a mathemati...

Cassan, Ludovic; Baume, Jean-pierre; Belaud, Gilles; Litrico, Xavier; Malaterre, Pierre-olivier; Ribot-bruno, Jose?

2011-01-01

257

The Control System Modeling and The Mechanical Structure Analysis For EMCVT  

OpenAIRE

The current automotive metallic belt continuously variable transmission (CVT) mostly use hydraulic system to push the cone disc and achieve the speed ratio control. A new Electrical Mechanical Continuously Variable Transmission without hydraulic control (Electrical Mechanical CVT, EMCVT) studied in this paper, uses the rolling screw mechanism to press cone disc, achieves speed regulation through the electronic control mechanism, and abandons the energy-intensive hydraulic system. In this pape...

Zhang, Lei; Cong, Xiaomei; Hujian Pan; Cai, Zuge; Yang, Xiumin

2013-01-01

258

Parameter Design for the Energy-Regeneration System of Series Hydraulic-Hybrid Bus  

OpenAIRE

This paper simplifies the energy recovery process in the series hydraulic hybrid bus’ energy regeneration system into a process in which the main axle’s moment of inertia drives the secondary element variable delivery pump/motor and brings hydraulic oil from the oil tank to the accumulator. This process enables braking of the vehicle and also allows recovery of energy to the accumulator. Based on the flow equation for the secondary element variable delivery pump/motor and the torque equil...

Song, Yunpu

2012-01-01

259

A Digital Hydraulic Valve, Actuated Using a Piezoelectric Linear Motor  

OpenAIRE

Proportional control in hydraulics is widely utilized. The most widely used current types of proportional valves utilize solenoid technology. While this technology has been around for decades and has been proven an effective means of control, there is always a demand for improved performance of advancing technologies. Integrating piezoelectric devices as a means to control hydraulic systems helps advance control for hydraulic systems. Piezoelectric stack devices have been used to contro...

Bevill, Brian C.

2011-01-01

260

Hydraulic air compressor as part of an ultra low-head hydropower system  

Science.gov (United States)

Analytical and experimental research was conducted to advance design and application tools and information concerning the hydraulic air compressor (HAC) for use in ultra low-head hydro-power systems. An existing analytical model of the HAC was significantly improved, mainly through incorporation of modeling of air absorption into the water in the flow processes. An experimental HAC was constructed, instrumented and tested. The experiments provided data for validation of the analytical model and information concerning air entrainment fixture design, air-water separator design, and operational and control characteristics of HAC. A computer program in which calculations using the analytical model were implemented was used to calculate and tabulate the applied head, water and air flow rate, depth, pressure, and compressor size relationships.

1982-05-01

261

Crosshole investigations - Details of the construction and operation of the hydraulic testing system  

International Nuclear Information System (INIS)

The Crosshole Programme, part of the international Stripa Project is designed to evaluate the effectiveness of various remote-sensing techniques in characterizing a rock mass around a repository. A multidisciplinary approach has been adopted in which various geophysical, mapping and hydrogeological methods are used to determine the location and characteristics of significant features in the rock. The Programme utilises six boreholes drilled in a fan array from the 360 metre level in the Stripa Mine, Sweden. The hydrogeological component of the work uses single and crosshole testing methods, including sinusoidal pressure testing, to locate fractures and characterize groundwater movement within them. Crosshole methods use packers to isolate portions of two boreholes which both intersect a significant feature in the rock mass. Hydraulic signals are generated in one isolated section and received in the other borehole. This report describes the design and operation of the computer-controlled system which automatically performs the hydrogeological tests. (authors)

262

Role of fracture zones in controlling hydraulic head and groundwater flow - experience from Site Characterization Program in Finland  

International Nuclear Information System (INIS)

The preliminary site investigations for the final disposal of HLW produced by TVO have been carried out during 1987-1992 in five areas. All the areas consist of Precambrian crystallite bedrock. The aim of these studies has been to identify and characterize geological structures, especially fractures and fracture zones with high hydraulic conductivity in order to study groundwater flow phenomena. Measured values of hydraulic head in packed-off sections of the boreholes have produced valuable information about the existence of hydraulically conductive fracture zones and their effects on spatial changes in hydraulic head and groundwater flow. The aim of this paper is to present qualitatively, without numerical simulations, how some main fracture zones control hydraulic head and groundwater flow in Romuvaara investigation area in Kuhmo, Finland

263

Electro-hydraulic load simulator device for control rod drives of HTRs  

International Nuclear Information System (INIS)

This article describes the structure and the mode of function of an electro-hydraulic cylinder driving mechanism for the simulation of fuel rod forces during insertion into the pebble bed core of a THTR-type reactor. The force simulation system is necessary for testing and adjusting of the pneumatic driving mechanism of the fuel rods before they are installed in the reactor. (orig.)

264

Coupled 3D hydrodynamic models for submarine outfalls. Denvironmental hydraulic design and control of multiport diffusers  

OpenAIRE

The book describes the hydraulic design and environmental impact prediction technologies for such installations. Focus are the hydrodynamics approached by computer models. First, a multiport diffuser design program was developed. Second, two model systems for discharge analysis, CORMIX for the near-field and intermediate-field and Delft3D for the far-field were coupled, and third a regulatory procedure is proposed to license and monitor outfall installations.

Bleninger, Tobias

2007-01-01

265

Analysis of core physics and thermal-hydraulics results of control rod withdrawal experiments in the LOFT facility  

International Nuclear Information System (INIS)

Two anticipated transient experiments simulating an uncontrolled control rod withdrawal event in a pressurized water reactor (PWR) were conducted in the Loss-of-Fluid Test (LOFT) Facility at the Idaho National Engineering Laboratory. The scaled LOFT 50-MW(t) PWR includes most of the principal features of larger commercial PWRs. The experiments tested the ability of reactor analysis codes to accurately calculate core reactor physics and thermal-hydraulic phenomena in an integral reactor system. The initial conditions and scaled operating parameters for the experiments were representative of those expected in a commercial PWR. In both experiments, all four LOFT control rod assemblies were withdrawn at a reactor power of 37.5 MW and a system pressure of 14.8 MPa

266

East integrated control system  

International Nuclear Information System (INIS)

EAST control system has been developed as network-based distributed control system composed of several subsystems. The integrated control system includes a supervisory control system, many local control systems, machine control and safety interlocks, data acquisition and management. The discharge control system, which is implemented in part of the CODAC (COntrol, Data Access and Communication) system, performs the discharge sequence execution. The development of the EAST integrated control system and commissioning results is presented in this paper.

267

East integrated control system  

Energy Technology Data Exchange (ETDEWEB)

EAST control system has been developed as network-based distributed control system composed of several subsystems. The integrated control system includes a supervisory control system, many local control systems, machine control and safety interlocks, data acquisition and management. The discharge control system, which is implemented in part of the CODAC (COntrol, Data Access and Communication) system, performs the discharge sequence execution. The development of the EAST integrated control system and commissioning results is presented in this paper.

Ji Zhenshan, E-mail: jizh@ipp.ac.c [Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, Hefei, Anhui 230031 (China); Wu Yichun [College of Physics and Information Engineering, Zhangzhou Normal University, Zhangzhou 363000 (China); Sun Xiaoyang; Li Shi; Yang Fei; Wang Yong; Du Xiaoying; Liu Dongmei; Zhang Ruirui; Liu Lianzhong [Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, Hefei, Anhui 230031 (China)

2010-07-15

268

Final design of a free-piston hydraulic advanced Stirling conversion system  

Science.gov (United States)

Under the US Department of Energy's (DOEs) Solar Thermal Technology Program, Sandia National Laboratories is evaluating heat engines for solar distributed receiver systems. The final design is described of an engineering prototype advanced Stirling conversion system (ASCS) with a free-piston hydraulic engine output capable of delivering about 25 kW of electric power to a utility grid. The free-piston Stirling engine has the potential for a highly reliable engine with long life because it has only a few moving parts, has noncontacting bearings, and can be hermetically sealed. The ASCS is designed to deliver maximum power per year over a range of solar input with a design life of 30 years (60,000 h). The system includes a liquid Nak pool boiler heat transport system and a free-piston Stirling engine with high-pressure hydraulic output, coupled with a bent axis variable displacement hydraulic motor and a rotary induction generator.

Wallace, D. A.; Noble, J. E.; Emigh, S. G.; Ross, B. A.; Lehmann, G. A.

1991-01-01

269

Development study on hydraulic three-dimensional seismic isolation system applied to advanced nuclear power plant. Development study on hydraulic rocking suppression system  

International Nuclear Information System (INIS)

Three-dimensional (3D) seismic isolation devices have been developed for the base isolation system of the Fast Breeder Reactor (FBR) that is an advanced nuclear reactor power plant building. The developed seismic isolation system consists of the hydraulic type vertical springs with rocking suppression mechanism and the laminated rubber bearings for horizontal direction. The isolation performances, i.e. natural period, damping, and rocking-suppression, have already been evaluated by the technical feasibility study and performance tests on a system which consists of down-sized devices on the shaking table, but in the seismic simulation on the real size building with this system, high hydraulic pressure was generated by rocking-suppression device under an extremely large seismic motion. In this paper, it is reported the frictional characteristics on high hydraulic pressure condition from the experiments on the 1/2 size of real device. To improve the damping performance of rocking-suppression, the orifice was added to the cylinder. At first the linear seismic simulation model of the real size system was constructed and damping coefficient was optimized by using that linear model. Finally, the detailed nonlinear simulation model was constructed, and time history analysis under simultaneous horizontal and vertical seismic motion was carried out, and the damping performance of rocking-suppression device was verified. (author)

270

Control of hydraulic pressure cracking on multiphase metallogenesis of vein shape granite-type uranium deposit in Miaoershan orefield  

International Nuclear Information System (INIS)

Morphologies and intertexture of ore veins in vein shape granite-type uranium deposits in Miaoershan ore field in north of Guangxi are studied in detail through using the hydraulic pressure cracking theory and various kinds of testing technique. It is known that the pressure on ore fluid is larger than that of wall rock, and the ore veins are formed by hydraulic pressure cracking. Based on the above discussion, the control of hydraulic pressure cracking on the multiphase metallogenesis of vein shape granite-type uranium deposits is discussed. (author)

271

Research and development on the hydraulic design system of the guide vanes of multistage centrifugal pumps  

International Nuclear Information System (INIS)

To improve the hydraulic design accuracy and efficiency of the guide vanes of the multistage centrifugal pumps, four different-structured guide vanes are investigated, and the design processes of those systems are established. The secondary development platforms of the ObjectArx2000 and the UG/NX OPEN are utilized to develop the hydraulic design systems of the guide vanes. The error triangle method is adopted to calculate the coordinates of the vanes, the profiles of the vanes are constructed by Bezier curves, and then the curves of the flow areas along the flow-path are calculated. Two-dimensional and three-dimensional hydraulic models can be developed by this system.

272

A development method for the thermal hydraulic transient analysis of parallel channel system  

International Nuclear Information System (INIS)

Parallel channel system is very typical in nuclear power plant, such as in the core and the steam generator. In this paper the author developed one model and a set of codes for the thermal hydraulic transient analysis of a core parallel channel system in QinShan II nuclear power plant. The basic model was built by Clausse and Lahey (1990) and developed by Lee and Pan (1999). In the original model the channel is divided into three parts: entrance section, heater section and riser section. The integral method is used to calculate the pressure of each section. It can reflect the whole characteristics of such system except the local parameters. And the nonuniform heating is very hard to be considered in this model. And the code based on this model is very hard to be coupled with reactor physics code in the future. Hence, the control volume concept is introduced to overcome these weaknesses. The channel can be divided into sufficient control volumes to describe the details. A development model is built based on this concept. Many classical flow and heat transfer correlations and models are included. The Gear method is chosen as the solving implement of the differential equations. Then a code is compiled. And then the transient characteristics are obtained under single and two-phase conditions. The transients of blocking, reactivity insertion and loss of flow are investigated based on imaginary data. At last a coupled method is conceived. (author)eived. (author)

273

OFDM PLC transmission for aircraft flight control system  

OpenAIRE

In the new civil aircrafts, hydraulic flight control systems are being replaced by electrically powered controls. The main interests are a better flexibility and a decrease in maintenance costs. Though the electrical wiring will replace the hydraulic tubing, it is essential to limit as much as possible the amount of electrical wiring. In order to decrease the total wires length, it is proposed to use power line communications (PLC) technology for data transmission over a high voltage direct c...

Larhzaoui, Thomas; Nouvel, Fabienne; Baudais, Jean-yves; Degauque, Pierre; Degardin, Virginie

2014-01-01

274

Fault Diagnosis for Nonlinear Hydraulic-Mechanical Drilling Pipe Handling System  

DEFF Research Database (Denmark)

Leakage and increased friction are common faults in hydraulic cylinders that can have serious consequences if they are not detected at early stage. In this paper, the design of a fault detector for a nonlinear hydraulic mechanical system is presented. By considering the system in steady state, two residual signals are generated and analysed with a composite hypothesis test which accommodates for unknown parameters. The resulting detector is able to detect abrupt changes in leakage or friction given the noisy pressure and position measurements. Test rig measurements validate the properties of residuals and high fidelity simulation and experimental results demonstrate the performance and feasibility of the proposed method.

Choux, Martin; Blanke, Mogens

2011-01-01

275

Ecohydrological controls on soil moisture and hydraulic conductivity within a pinyon-juniper woodland  

Science.gov (United States)

The impact of pinyon-juniper woodland encroachment on rangeland ecosystems is often associated with a reduction of streamflow and recharge and an increase in soil erosion. The objective of this study is to investigate vegetational control on seasonal soil hydrologic properties along a 15-m transect in pinyon-juniper woodland with biocrust. We demonstrate that the juniper tree controls soil water content (SWC) patterns directly under the canopy via interception, and beyond the canopy via shading in a preferred orientation, opposite to the prevailing wind direction. The juniper also controls the SWC and unsaturated hydraulic conductivity measured close to water saturation (K(h)) under the canopy by the creation of soil water repellency due to needle drop. We use this information to refine the hydrologic functional unit (HFU) concept into three interacting hydrologic units: canopy patches, intercanopy patches, and a transitional unit formed by intercanopy patches in the rain shadow of the juniper tree. Spatial autoregressive state-space models show the close relationship between K(h) close to soil water saturation and SWC at medium and low levels, integrating a number of influences on hydraulic conductivity. Copyright 2007 by the American Geophysical Union.

Lebron, I.; Madsen, M.D.; Chandler, D.G.; Robinson, D.A.; Wendroth, O.; Belnap, J.

2007-01-01

276

Engine with hydraulic fuel injection and ABS circuit using a single high pressure pump  

Science.gov (United States)

An engine system comprises a hydraulically actuated fuel injection system and an ABS circuit connected via a fluid flow passage that provides hydraulic fluid to both the fuel injection system and to the ABS circuit. The hydraulically actuated system includes a high pressure pump. The fluid control passage is in fluid communication with an outlet from the high pressure pump.

Bartley, Bradley E. (Manito, IL); Blass, James R. (Bloomington, IL); Gibson, Dennis H. (Chillicothe, IL)

2001-01-01

277

Investigations into the use of water glycol as the hydraulic fluid in a servo system  

International Nuclear Information System (INIS)

The effects of water glycol on the performance of a hydraulic system and on the life of the system components have been investigated and a guide to the design of systems using water glycol is given. The dynamic performance of the system using water-glycol was compared with that using mineral oil, then the system was endurance tested to determine its service life. (author)

278

Study of the performance of four repairing material systems for hydraulic structures of concrete dams  

Directory of Open Access Journals (Sweden)

Full Text Available Four types of repairing materials are studied as function of either a conventional concrete or a reference-concrete (RefC, these are: polymer-modified cement mortar (PMor, steel fiber concrete (SFco, epoxy mortar (EMor and silica fume mortar (SFmo, to be applied in hydraulic structures surfaces subjected to a high velocity water flow. Besides the mechanical requests and wearing resistance of hydraulic concrete dam structures, especially the spillway surfaces, the high solar radiation, the environmental temperature and wet and dry cycles, contribute significantly to the reduction of their lifespan. RefC and the SFco were developed based on a usual concrete mixture used in slabs of spillways. The average RefC mixture used was 1: 1.61: 2.99: 0.376, with Pozzolan-modified Portland cement consumption of 425 kg/m³. EMor and PMor mixtures followed the information given by the manufacturers and lab experience. Tests on concrete samples were carried out in laboratory simulating normally found environmental situations in order to control the mechanical resistance and the aging imposed conditions, such as solar radiation and humidity. Also, physicochemical characterizing tests were made for all used materials. From the analyzed results, two of them presented a higher performance: the EMor and SFmo. SFco presented good adherence to the RefC and good mechanical performance. However, it also presented apparent metal corrosion in humidity tests, being indicated for use, with caution, as an intermediate layer in underwater repairs. In a general classification, considering all tests, including their field applications, the better performance material systems were EMor- SFmo> SFco> PMor.

Kormann A. C. M.

2003-01-01

279

A study on the optimal hydraulic loading rate and plant ratios in recirculation aquaponic system.  

Science.gov (United States)

The growths of the African catfish (Clarias gariepinus) and water spinach (Ipomoea aquatica) were evaluated in recirculation aquaponic system (RAS). Fish production performance, plant growth and nutrient removal were measured and their dependence on hydraulic loading rate (HLR) was assessed. Fish production did not differ significantly between hydraulic loading rates. In contrast to the fish production, the water spinach yield was significantly higher in the lower hydraulic loading rate. Fish production, plant growth and percentage nutrient removal were highest at hydraulic loading rate of 1.28 m/day. The ratio of fish to plant production has been calculated to balance nutrient generation from fish with nutrient removal by plants and the optimum ratio was 15-42 gram of fish feed/m(2) of plant growing area. Each unit in RAS was evaluated in terms of oxygen demand. Using specified feeding regime, mass balance equations were applied to quantify the waste discharges from rearing tanks and treatment units. The waste discharged was found to be strongly dependent on hydraulic loading rate. PMID:19819130

Endut, Azizah; Jusoh, A; Ali, N; Wan Nik, W B; Hassan, A

2010-03-01

280

Comparison for the interfacial and wall friction models in thermal-hydraulic system analysis codes  

Energy Technology Data Exchange (ETDEWEB)

The average equations employed in the current thermal hydraulic analysis codes need to be closed with the appropriate models and correlations to specify the interphase phenomena along with fluid/structure interactions. This includes both thermal and mechanical interactions. Among the closure laws, an interfacial and wall frictions, which are included in the momentum equations, not only affect pressure drops along the fluid flow, but also have great effects for the numerical stability of the codes. In this study, the interfacial and wall frictions are reviewed for the commonly applied thermal-hydraulic system analysis codes, i.e. RELAP5-3D, MARS-3D, TRAC-M, and CATHARE.

Hwang, Moon Kyu; Park, Jee Won; Chung, Bub Dong; Kim, Soo Hyung; Kim, See Dal

2007-07-15

281

East Integrated Control System  

International Nuclear Information System (INIS)

EAST control system has been developed as network-based distributed control system composed of several sub-systems. The integrated control system includes a supervisory control system, many local control systems, machine control and safety interlocks, data acquisition and management. The discharge control system, which is implemented in part of the supervisory control system, performs the discharge sequence execution. We will present the details of the development of the EAST integrated control system and commissioning results. This document is composed of an abstract followed by the slides of the presentation. (authors)

282

East Integrated Control System  

Energy Technology Data Exchange (ETDEWEB)

EAST control system has been developed as network-based distributed control system composed of several sub-systems. The integrated control system includes a supervisory control system, many local control systems, machine control and safety interlocks, data acquisition and management. The discharge control system, which is implemented in part of the supervisory control system, performs the discharge sequence execution. We will present the details of the development of the EAST integrated control system and commissioning results. This document is composed of an abstract followed by the slides of the presentation. (authors)

Ji, Z.; Sun, X.; Wu, Y. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei (China)

2009-07-01

283

Aircraft Fuel, Hydraulic and Pneumatic Systems (Course Outlines), Aviation Mechanics 3 (Air Frame): 9067.01.  

Science.gov (United States)

This document presents an outline for a 135-hour course designed to familiarize the student with the operation, inspection, and repair of aircraft fuel, hydraulic, and pneumatic systems. It is designed to help the trainee master the knowledge and skills necessary to become an aviation airframe mechanic. The aviation airframe maintenance technician…

Dade County Public Schools, Miami, FL.

284

Development and Simulation of Mathematical Modelling of Hydraulic Turbine  

OpenAIRE

Power system performance is affected by dynamic characteristics of hydraulic governor-turbines during and following any disturbance, such as occurrence of a fault, loss of a transmission line or a rapid change of load. Accurate modelling of hydraulic System is essential to characterize and diagnose the system response. In this article the mathematical modeling of hydraulic turbine is presented. The model is capable to implement the digital systems for monitoring and control replacing the conv...

Singh, Gagan; Chauhan, D. S.

2011-01-01

285

Simulation analysis of pressure regulation of hydraulic thrust system on a shield tunneling machine  

Science.gov (United States)

Hydraulic thrust system is an important system in a shield tunneling machine. Pressure regulation of thrust cylinders is the most important function for thrust system during tunnel excavation. In this paper, a hydraulic thrust system is explained, and a corresponding simulation model is carried out in order to study the system characteristics. Pressure regulation of a certain group's cylinders has little influence on regulation of the other groups' cylinders. The influence will not affect the process much during tunnel excavation. Pump displacement may have a greater effect on pressure regulation and oil supply flow rate should be adaptive to the system's demand. A exacting situation is simulated to explain how pressure regulation works during tunnel excavation.

Liu, Zhibin; Xie, Haibo; Yang, Huayong

2011-09-01

286

Handbook of hydraulic fluid technology  

CERN Document Server

""The Handbook of Hydraulic Fluid Technology"" serves as the foremost resource for designing hydraulic systems and for selecting hydraulic fluids used in engineering applications. Featuring new illustrations, data tables, as well as practical examples, this second edition is updated with essential information on the latest hydraulic fluids and testing methods. The detailed text facilitates unparalleled understanding of the total hydraulic system, including important hardware, fluid properties, and hydraulic lubricants. Written by worldwide experts, the book also offers a rigorous overview of h

Totten, George E

2011-01-01

287

Thermal-hydraulic effects of transition to improved System 80TM fuel  

International Nuclear Information System (INIS)

ABB CE's improved System 80TM PWR fuel design includes GUARDIAN debris-resistant features and laser-welded Zircaloy grids. The GUARDIAN features include an Inconel grid with debris-filtering features located just above the Lower End Fitting, and a solid fuel rod bottom end cap that extends above the filtering features. Tests and analyses were done to establish the impact of these design improvements on fuel assembly hydraulic performance. Further analysis was done to determine the mixed core thermal-hydraulic performance as the transition is made over two fuel cycles to a full core of the improved System 80TM fuel. Results confirm that the Thermal-Hydraulic (T-H) effects of the reduction in hydraulic resistance between the improved and resident fuel due to the laser-welded Zircaloy grids offsets the effects of the increased resistance GUARDIAN grid. Therefore, the mechanically improved System 80TM fuel can be implemented with no net impact on Departure from Nucleate Boiling (DNB) margin in transition cores. (author)

288

Analysis of the Power Head Torque Loading System Based on Hydraulic Energy Closed-loop  

OpenAIRE

Power head with high power and large torque is the main power equipment of the rotary drilling rig. Aimed at the working condition, energy saving torque loading test program of power head was put forward and mathematical and simulation models of hydraulic energy closed-loop torque loading system were established in order to make an analysis of torque loading system. Combined with bond graph and state equations of torque loading system with single pump, effect of the logical relationshi...

Xianjin Shi

2013-01-01

289

Selecting Oil Wells for Hydraulic Fracturing: A Comparison between Genetic-Fuzzy and Neuro Fuzzy Systems  

OpenAIRE

Hydraulic fracturing is widely used to increase oil well production and to reduce formation damage. Reservoir studies and engineering analyses are carried out to select the wells for this kind of operation. As the reservoir parameters have some diffuse characteristics, Fuzzy Inference Systems (FIS) have been tested for these selection processes in the last few years. This paper compares the performance of a neuro fuzzy system and a genetic fuzzy system used for selec...

Virgílio José Martins Ferreira Filho; Antônio Orestes de Salvo Castro

2014-01-01

290

Thermal-hydraulics Analysis of a Radioisotope-powered Mars Hopper Propulsion System  

Energy Technology Data Exchange (ETDEWEB)

Thermal-hydraulics analyses results produced using a combined suite of computational design and analysis codes are presented for the preliminary design of a concept Radioisotope Thermal Rocket (RTR) propulsion system. Modeling of the transient heating and steady state temperatures of the system is presented. Simulation results for propellant blow down during impulsive operation are also presented. The results from this study validate the feasibility of a practical thermally capacitive RTR propulsion system.

Robert C. O' Brien; Andrew C. Klein; William T. Taitano; Justice Gibson; Brian Myers; Steven D. Howe

2011-02-01

291

Thermal-hydraulics Analysis of a Radioisotope-powered Mars Hopper Propulsion System  

International Nuclear Information System (INIS)

Thermal-hydraulics analyses results produced using a combined suite of computational design and analysis codes are presented for the preliminary design of a concept Radioisotope Thermal Rocket (RTR) propulsion system. Modeling of the transient heating and steady state temperatures of the system is presented. Simulation results for propellant blow down during impulsive operation are also presented. The results from this study validate the feasibility of a practical thermally capacitive RTR propulsion system.

292

Thermal-hydraulic system study of a high pressure, high temperature helium loop using RELAP5-3D code  

International Nuclear Information System (INIS)

Highlights: ? A thermal-hydraulic system analysis for a high pressure, high temperature helium loop has been investigated. ? The loop belongs to the Helium Loop Karlsruhe (HELOKA) facility, which contains the European Helium Cooled Pebble Beds Test Blanket Module (HCPB TBM) as the test module. ? The loop including all components has been modeled using the system code REALP5-3D, and the main control strategy has been implemented as well. ? With this model, the loop dynamics in conditions relevant for blanket module operation have been demonstrated. - Abstract: The thermal-hydraulic system analysis for the Helium Loop Karlsruhe (HELOKA) facility, a high pressure, high temperature experimental helium loop having the European Helium Cooled Pebble Beds Test Blanket Module (HCPB TBM) as the test module, was investigated. Using the system code REALP5-3D, all components in the loop are modeled as well as the main control strategy. With this model, the loop dynamics in conditions relevant for blanket module operation are simulated and analyzed.

293

RE-1000 free-piston Stirling engine hydraulic output system description  

Science.gov (United States)

The NASA Lewis Research Center was involved in free-piston Stirling engine research since 1976. Most of the work performed in-house was related to characterization of the RE-1000 engine. The data collected from the RE-1000 tests were intended to provide a data base for the validation of Stirling cycle simulations. The RE-1000 was originally build with a dashpot load system which did not convert the output of the engine into useful power, but was merely used as a load for the engine to work against during testing. As part of the interagency program between NASA Lewis and the Oak Ridge National Laboratory, (ORNL), the RE-1000 was converted into a configuration that produces useable hydraulic power. A goal of the hydraulic output conversion effort was to retain the same thermodynamic cycle that existed with the dashpot loaded engine. It was required that the design must provide a hermetic seal between the hydraulic fluid and the working gas of the engine. The design was completed and the hardware was fabricated. The RE-1000 was modified in 1985 to the hydraulic output configuration. The early part of the RE-1000 hydraulic output program consisted of modifying hardware and software to allow the engine to run at steady-state conditions. A complete description of the engine is presented in sufficient detail so that the device can be simulated on a computer. Tables are presented showing the masses of the oscillating components and key dimensions needed for modeling purposes. Graphs are used to indicate the spring rate of the diaphragms used to separate the helium of the working and bounce space from the hydraulic fluid.

Schreiber, Jeffrey G.; Geng, Steven M.

1987-01-01

294

A Hydraulic Motor-Alternator System for Ocean-Submersible Vehicles  

Science.gov (United States)

An ocean-submersible vehicle has been developed at JPL that moves back and forth between sea level and a depth of a few hundred meters. A liquid volumetric change at a pressure of 70 bars is created by means of thermal phase change. During vehicle ascent, the phase-change material (PCM) is melted by the circulation of warm water and thus pressure is increased. During vehicle descent, the PCM is cooled resulting in reduced pressure. This pressure change is used to generate electric power by means of a hydraulic pump that drives a permanent magnet (PM) alternator. The output energy of the alternator is stored in a rechargeable battery that powers an on-board computer, instrumentation and other peripherals.The focus of this paper is the performance evaluation of a specific hydraulic motor-alternator system. Experimental and theoretical efficiency data of the hydraulic motor and the alternator are presented. The results are used to evaluate the optimization of the hydraulic motor-alternator system. The integrated submersible vehicle was successfully operated in the Pacific Ocean near Hawaii. A brief overview of the actual test results is presented.

Aintablian, Harry O.; Valdez, Thomas I.; Jones, Jack A.

2012-01-01

295

Parameter Design for the Energy-Regeneration System of Series Hydraulic-Hybrid Bus  

Directory of Open Access Journals (Sweden)

Full Text Available This paper simplifies the energy recovery process in the series hydraulic hybrid bus’ energy regeneration system into a process in which the main axle’s moment of inertia drives the secondary element variable delivery pump/motor and brings hydraulic oil from the oil tank to the accumulator. This process enables braking of the vehicle and also allows recovery of energy to the accumulator. Based on the flow equation for the secondary element variable delivery pump/motor and the torque equilibrium equation for its axle, the force equilibrium equation for vehicle braking and the pressure variation and flow continuity equations for the accumulator, simulation studies are conducted to analyze the effects of various system parameters, such as accumulator capacity, displacement of the secondary element variable delivery pump/motor, initial operating pressure of the system, etc. on system performance during regenerative braking.  

SONG Yunpu

2012-10-01

296

RAMONA-3B/MINET composite representation of BWR thermal-hydraulic systems  

International Nuclear Information System (INIS)

The modification and interfacing of two computer codes, RAMONA-3B and MINET, for the thermal hydraulic transient analysis of a Boiling Water Reactor nuclear steam supply system, is described. The RAMONA-3B code provides for multi-channel thermal hydraulics and three-dimensional (or one-dimensional) neutron kinetics analysis of a boiling water reactor core. The RAMONA-3B system representation terminates at the end of the steam line and at the junction of the feedwater line at the vessel inlet. By interfacing RAMONA-3B with MINET, a generic balance-of-plant systems analysis code, a complete BWR systems code with detailed core modeling was obtained. The result is a code of particulate importance to the analysis of transients such as ATWS

297

RAMONA-3B/MINET composite representation of BWR thermal-hydraulic systems  

International Nuclear Information System (INIS)

The modification and interfacing of two computer codes, RAMONA-3B and MINET, for the thermal hydraulic transient analysis of a Boiling Water Reactor nuclear steam supply system, is described. The RAMONA-3B code provides for multi-channel thermal hydraulics and three-dimensional (or one-dimensional) neutron kinetics analysis of a boiling water reactor core. The RAMONA-3B system representation terminates at the end of the steam line and at the junction of the feedwater line at the vessel inlet. By interfacing RAMONA-3B with MINET, a generic balance-of-plant systems analysis code, a complete BWR systems code with detailed core modeling was obtained. The result is a code of particular importance to the analysis of transients such as ATWS. A comparison between the 3-D and 1-D neutronics representation is provided, along with a test case utilizing the composite RAMONA-3B/MINET code

298

Comparison of analytical repsonse of piping systems supported by various hydraulic restraint devices  

International Nuclear Information System (INIS)

Restraint devices, commonly known as snubbers, are installed in piping systems to limit stresses due to potentially damaging transients. A compressible fluid snubber model is developed in this study based on the inherent velocity sensitive and hydraulic characteristics of one class of these restraint devices. For piping systems with these restraint devices installed, the steady-state response of the system can be obtained by employing a transfer function concept. Utilizing this method, the Laplace transform with respect to time is employed in order to obtain an interaction equation which combines the piping system's equations of motion with the snubber's fluid pressure equations. With this interaction equation, the model for the piping system supported by a compressible fluid hydraulic snubber is developed and piping system response is predicted for various excitation conditions. For these piping systems, time history analysis is performed in a piecewise linear fashion. This enables the analysis to characterize the snubber in each of the two conditions (locked or unlocked) that occur as a result of forced motion. The value of fluid pressure in the hydraulic snubber is used as a test criterion in the solution a logarithm of the compressible fluid model to determine the locked/unlocked condition of the snubber. (orig./RW)

299

Improvements to the measurement of electrically controlled hydraulic pumps' flow/pressure characteristics  

International Nuclear Information System (INIS)

To increase the measurement accuracy, and also to automate the measurement operation, we modify the electrically controlled hydraulic pumps' (ECHPs') flow/pressure performance characteristic description and improve the test method in existent standards. According to ECHPs' working principle, we divide ECHPs' operation into two models: constant flow operating mode (CFOM) and constant pressure operating mode (CPOM). A direct drive servo-proportional control valve (DDV) is used to load the test pump. In the CFOM, we change the pressure load at a constant rate by driving the DDV's displacement with nonlinear feedback and a proportional–integral (PI) controller. In the CPOM, we take advantage of the DDV's inherent linearity between its input signal and output flow, and change the flow load at a constant rate by using open-loop spool displacement control. A mathematic model is built for the derivation of a stable condition and the analysis of steady-state pressure tracking error. The theoretical analysis shows that the feedback linearization and PI controller with negative proportional and integral gains are able to track a slope pressure load command with a desired rate. The test results also show that the mathematical model is valid and the proposed method can improve the measurement accuracy remarkably

300

Sensitivity analysis of a passive thermal-hydraulic system  

International Nuclear Information System (INIS)

Full text of publication follows. Passive safety features are now of interest to the design of future generation reactors. Though passive safety systems are considered to be more reliable, the large uncertainty associated with the system response can not be ignored. It is necessary to identify the uncertain inputs that have the important impact on the uncertainty of the system performance. In this study, two global sensitivity measures, the first-order sensitivity index and the total-order sensitivity index, are applied to a passive decay heat removal system of a gas-cooled fast reactor for identifying the key uncertainty inputs. It is found that the uncertainty in the system pressure contributes the most to the uncertainty in the system outputs. In addition, the cooler wall temperature, the Nusselt number in the mixed convection regime and the friction factor in the mixed convection flow regime also have small impact on the uncertainty of the system outputs. (authors)

301

Modeling with AFT Fathom of hydraulic systems. Application to the Asco nuclear power station  

International Nuclear Information System (INIS)

This paper gives an overview of the simulation of hydraulic systems with program AFT Fathom, describing practical applications carried out in NPP Asco. The results of the simulation are used to determine the behavior certain systems under hardly reproducible scenarios in reality, such as emergency and accident situations. In this sense, are presented real-life examples carried out in C. N. disgust and shown how the simulation puts in the hands of engineers valuable information for decision-making.

302

FOREWORD: The XXV IAHR Symposium on Hydraulic Machinery and Systems marks half a century tradition  

Science.gov (United States)

IAHR75_logoUPT90_logoARFT_logo International Association of Hydro-Environment Engineering and Research'Politehnica' University of TimisoaraRomanian Academy - Timisoara Branch The 25th edition of the IAHR Symposium on Hydraulic Machinery and Systems, held in Timisoara, Romania, 20-24 September 2010, jointly organized by the 'Politehnica' University of Timisoara and the Romanian Academy - Timisoara Branch, marks a half century tradition of these prestigious symposia. However, it is the first time that Romania hosts such a symposium, and for good reasons. The Romanian electrical power system has a total of 20,630 MW installed power, out of which 6,422 MW in hydropower plants. The energy produced in hydropower facilities was in 2008 of 17,105 GWh from a total of 64,772 GWh electrical energy production. Moreover, for the period 2009-2015, new hydropower capacities are going to be developed, with a total of 2,157 MW installed power and an estimated 5,770 GWh/year energy production. Within the same period of time, the refurbishment, modernization and repair programs will increase the actual hydropower production with an estimated 349 GWh/year. The 'Politehnica' University of Timisoara is proud to host the 25th IAHR Symposium on Hydraulic Machinery and Systems, in the year of its 90th anniversary. The 'Politehnica' University of Timisoara is one of the largest and most well-known technical universities from Central and Eastern Europe. It was founded in 1920, a short time after the union into one state of all the Romanian territories, following the end of the First World War, in order to respond to the need engineers felt by the Romanian society at that time, within the economical development framework. During its 90 years of existence, 'Politehnica' University of Timisoara educated over 100,000 engineers, greatly appreciated both in Romania and abroad, for their competence and seriousness. King Ferdinand I of Romania said while visiting the recently established 'Politehnica' of Timisoara in 1923 'It is not the walls that make a school, but the spirit living inside'. A particular trademark of the 'Politehnica' of Timisoara was the continuous effort to answer industrial problems by training the students not only on theoretical aspects but also in design and manufacturing, as well as in laboratory works. Developing modern laboratories, where students can observe and understand first hand the engineering applications along the years a priority for Timisoara 'Politehnica' University. The School of Hydraulic Machinery within the 'Politehnica' University of Timisoara was established in early 1930 by Professor Aurel Barglazan (1905-1960), and further developed by Professor Ioan Anton (born 1924), both members of the Romanian Academy. The Laboratory of Hydraulic Machines from Timisoara (LMHT) started back in 1928 in a small hut, with a test rig for Francis and Kaplan turbines manufactured by J M Voith. LMHT was continuously developed and was officially recognized in 1959 as being one of the leading research and developing laboratories in Romania. It was the foundation of the Romanian efforts of designing and manufacturing hydraulic turbines starting in 1960 at the Resita Machine Building Factory. Under the leadership of Professor Ioan Anton, the Timisoara School in Hydraulic Machinery has focused the basic and development research activities on the following main topics: (i) Turbine Hydrodynamics, (ii) Hydrofoil Cascade Hydrodynamics, (iii) Cavitation in Hydraulic Machines and Equipments, (iv) Scale-up Effects in Hydraulic Machines. With the establishment in the year 2000 of the National Center for Engineering of Systems with Complex Fluids, within the 'Politehnica' University of Timisoara, the research in turbomachinery hydrodynamics and cavitation included high performance computing for flows in hydraulic machines, as well as the development of novel technologies to mitigate the self-induced flow instabilities in hydraulic turbines operated far from the best efficiency regime. The traditional partnership with the Romanian Academy - Tim

Susan-Resiga, Romeo

2010-05-01

303

Hydraulic modeline of pump systems in water distribution networks  

OpenAIRE

Water distribution networks provide water supply to consumers. Pumping system adds mechanical work, thus providing sufficient amount of energy for water distribution throughout network. Pump's mechanical work is made by consuming electrical power. Because consumption of electricity and costs of consumed energy are high improvements made on operation of pumping system can lead to non negligible savings. When optimising pump system's operation different factors have to be taken into account (hy...

Robic?, Gregor

2013-01-01

304

Improvement of multi-dimensional realistic thermal-hydraulic system analysis code, MARS 1.3  

International Nuclear Information System (INIS)

The MARS (Multi-dimensional Analysis of Reactor Safety) code is a multi-dimensional, best-estimate thermal-hydraulic system analysis code. This report describes the new features that have been improved in the MARS 1.3 code since the release of MARS 1.3 in July 1998. The new features include: - implementation of point kinetics model into the 3D module - unification of the heat structure model - extension of the control function to the 3D module variables - improvement of the 3D module input check function. Each of the items has been implemented in the developmental version of the MARS 1.3.1 code and, then, independently verified and assessed. The effectiveness of the new features is well verified and it is shown that these improvements greatly extend the code capability and enhance the user friendliness. Relevant input data changes are also described. In addition to the improvements, this report briefly summarizes the future code developmental activities that are being carried out or planned, such as coupling of MARS 1.3 with the containment code CONTEMPT and the three-dimensional reactor kinetics code MASTER 2.0. (author). 8 refs

305

High Resolution Hydraulic Profiling and Groundwater Sampling using FLUTe™ System in a Fractured Limestone Setting  

DEFF Research Database (Denmark)

Characterization of the contaminant source zone architecture and the hydraulics is essential to develop accurate site specific conceptual models, delineate and quantify contaminant mass, perform risk as-sessment, and select and design remediation alternatives. This characterization is particularly challeng-ing in deposit types as fractured limestone. The activities of a bulk distribution facility for perchloroe-thene (PCE) and trichloroethene (TCE) at the Naverland site near Copenhagen, Denmark, has resulted in PCE and TCE DNAPL impacts to a fractured clay till and an underlying fractured limestone aqui-fer/bedrock. A wide range of innovative and current site investigative tools for direct and indirect docu-mentation and/or evaluation of dense non-aqueous phase liquid (DNAPL) presence were combined in a multiple lines of evidence approach. One scope of the investigations was to evaluate innovative investi-gation methods for characterization of the source zone hydrogeology and contamination, including FLUTe system hydraulic profiling and Water-FLUTe multilevel groundwater sampling, in fractured bryo-zoan limestone bedrock. High resolution hydraulic profiling was conducted in three cored boreholes, placed within a 970 ft2 (~90 m2) area, and Water-FLUTes were installed with 12-13 sampling screens in each borehole. Hydraulic profilling by FLUTe liner system provided information with highere discretization than other traditionel methods, and supported the individual design of Water-FLUTes for multilevel groundwater monitoring, sampling (under two flow conditions) and analysis. Coring for discrete subsampling was a challenge in the limestone, due to core-loss and potential DNAPL loss caused by high drilling water pressure. Hence, the water-FLUTe data proved to be an essential link in the source zone characterization. The results from the high resolution hydraulic profiling and from the Water-FLUTe multilevel sampling will be pre-sented as well as the experiences obtained.

Janniche, Gry Sander; Christensen, Anders G.

306

Development of a thermal–hydraulic analysis software for a passive residual heat removal system  

International Nuclear Information System (INIS)

Highlights: ? A series of thermal–hydraulic models for the PRHRS in IPWR were established. ? An analysis software named TCIPsoft 1.0 has been developed. ? The effects of parameters on the PRHRS were studied in detail. -- Abstract: A series of reasonable mathematical and physical models for the thermal–hydraulic characteristic analysis of a passive residual heat removal system (PRHRS) in an integral pressurized water reactor were established. These models mainly include the core, once-through steam generator, nitrogen pressurizer, main coolant pump, and flow and heat transfer models. The flow and heat transfer models are suitable for the core with plate-type fuel element and the once-through steam generator with annular channel, respectively. A transient analysis code with Visual Fortran 6.5 has been developed to analyze the thermal–hydraulic characteristics of the PRHRS. Visual input, real-time processing and dynamic visualization output were achieved with Microsoft Visual Studio.NET 2008, which greatly facilitate applications in the engineering. The software was applied to analyze the effects of the heat transfer area of the PRHRS, the height difference between the residual heat exchanger center and the steam generator center, and the main steam valve turn-off time on the transient thermal–hydraulic characteristics of PRHRS. The obtained analysis results are significant to the improvement design of the PRHRS and the safety operation of the integral preseration of the integral pressurized water reactor.

307

Analytical and experimental investigation of chlorine decay in water supply systems under unsteady hydraulic conditions  

DEFF Research Database (Denmark)

This paper investigates the impact of the dynamic hydraulic conditions on the kinetics of chlorine decay in water supply systems. A simulation framework has been developed for the scale-adaptive hydraulic and chlorine decay modelling under steady- and unsteady-state flows. An unsteady decay coefficient is defined which depends upon the absolute value of shear stress and the rate of change of shear stress for quasi-unsteady and unsteady-state flows. By coupling novel instrumentation technologies for continuous hydraulic monitoring and water quality sensors for in-pipe water quality sensing a pioneering experimental and analytical investigation was carried out in a water transmission main. The results were used to model monochloramine decay and these demonstrate that the dynamic hydraulic conditions have a significant impact on water quality deterioration. The spatial and temporal resolution of experimental data provides new insights for the near real-time modelling and management of water quality as well as highlighting the uncertainty and challenges of accurately modelling the loss of disinfectant in water supply networks.

Aisopou, Angeliki; Stoianov, Ivan

2013-01-01

308

BSF control system  

International Nuclear Information System (INIS)

The booster synchrotron utilization facility (BSF) is a facility which utilizes the four fifths of available beam pulses from the KEK booster synchrotron. The BSF control system includes the beam line control, interactions with the PS central control room and the experimental facilities, and the access control system. A brief description of the various components in the control system is given. (author)

309

Summary of the hydraulic evaluation of LWBR (LWBR development program)  

International Nuclear Information System (INIS)

The principal hydraulic performance features of the Light Water Breeder Reactor are summarized in this report. The calculational models and procedures used for prediction of reactor flow and pressure distributions under steady-state and transient operating conditions are described. Likewise, the analysis models for evaluation of the static and dynamic performance characteristics of the hydraulically-balanced and hydraulically-buffered movable-fuel reactivity-control system are outlined. An extensive test program was conducted for qualification of the subject LWBR hydraulic evaluation models. The projected LWBR hydraulic performance is shown to fulfill design objectives and functional requirements

310

Staged cost optimization of urban storm drainage systems based on hydraulic performance in a changing environment  

Directory of Open Access Journals (Sweden)

Full Text Available Urban flooding causes large economic losses, property damage and loss of lives. The impact of environmental changes, mainly urbanization and climatic change, leads to increased runoff and peak flows which the drainage system must be able to cope with to reduce potential damage and inconvenience. Allowing for detention storage to compliment the conveyance capacity of the drainage system network is one of the approaches to reduce urban floods. Contemporary practice is to design systems against stationary environmental forcings – including design rainfall, landuse, etc. Due to the rapid change in the climate- and the urban environment, this approach is no longer appropriate, and explicit consideration of gradual changes during the life-time of the drainage system is warranted. In this paper, a staged cost optimization tool based on the hydraulic performance of the drainage system is presented. A one dimensional hydraulic model is used for hydraulic evaluation of the network together with a genetic algorithm based optimization tool to determine optimal intervention timings and responses over the analysis period. The model was applied in a case study area in the city of Porto Alegre, Brazil. It was concluded that considerable financial savings and/or additional level of flood-safety can be achieved by approaching the design problem as a staged plan rather than one-off scheme.

M. Maharjan

2009-04-01

311

Staged cost optimization of urban storm drainage systems based on hydraulic performance in a changing environment  

Directory of Open Access Journals (Sweden)

Full Text Available Urban flooding causes large economic losses, property damage and loss of lives. The impact of environmental changes mainly, the urbanization and the climatic change leads to increased runoff and increased peak flows which the drainage system must be able to cope with to overcome possible damage and inconveniences caused by the induced flooding. Allowing for detention storage to compliment the capacity of the drainage system network is one of the approaches to reduce urban floods. The traditional practice was to design systems against stationary environmental forcings – including design rainfall, landuse, etc. Due to the rapid change in climate-environment, this approach is no longer economically viable and safe, and explicit consideration of changes that gradually take place during the life-time of the drainage system is warranted. In this paper, a staged cost optimization tool based on the hydraulic performance of the drainage system is presented. A one dimensional hydraulic model is used for hydraulic evaluation of the network together with a genetic algorithm based optimization tool to determine optimal intervention timings and amounts throughout the lifespan of the drainage network. The model was applied in a case study area in the city of Porto Alegre, Brazil. It was concluded that considerable financial savings and/or additional level of flood-safety can be achieved by approaching the design problem as a staged plan rather than one-off scheme.

M. Maharjan

2008-06-01

312

Free-piston Stirling hydraulic engine and drive system for automobiles  

Science.gov (United States)

The calculated fuel economy for an automotive free piston Stirling hydraulic engine and drive system using a pneumatic accumulator with the fuel economy of both a conventional 1980 spark ignition engine in an X body class vehicle and the estimated fuel economy of a 1984 spark ignition vehicle system are compared. The results show that the free piston Stirling hydraulic system with a two speed transmission has a combined fuel economy nearly twice that of the 1980 spark ignition engine - 21.5 versus 10.9 km/liter (50.7 versus 25.6 mpg) under comparable conditions. The fuel economy improvement over the 1984 spark ignition engine was 81 percent. The fuel economy sensitivity of the Stirling hydraulic system to system weight, number of transmission shifts, accumulator pressure ratio and maximum pressure, auxiliary power requirements, braking energy recovery, and varying vehicle performance requirements are considered. An important finding is that a multispeed transmission is not required. The penalty for a single speed versus a two speed transmission is about a 12 percent drop in combined fuel economy to 19.0 km/liter (44.7 mpg). This is still a 60 percent improvement in combined fuel economy over the projected 1984 spark ignition vehicle.

Beremand, D. G.; Slaby, J. G.; Nussle, R. C.; Miao, D.

1982-01-01

313

Optimal design of the positions of the hoops for a hydraulic pipelines system  

International Nuclear Information System (INIS)

Highlights: ? The parametric model of the hydraulic pipelines system is constructed by ANASYS. ? The above parametric model can be called by MATLAB. ? An optimization model for the positions of the hoops is established. ? An optimization for the positions of the hoops is performed. - Abstract: This paper focuses on decreasing the vibration and improving the dynamics performances for a hydraulic pipelines system. The parametric model of the hydraulic pipelines system under the random excitations is constructed and the dynamics characteristics are obtained by the finite element analysis, then an optimization model is presented to reduce the vibration by rationally designing the positions of the hoops in the pipelines system. The dimensions determining the locations of the hoops are defined as design variables, and the dynamics performances, such as the maximum displacement, the maximum axial stress, the maximum shear stress, the maximum axial strain, the maximum hoop strain, the maximum shear strain and the failure probability of the first passage are regarded as nonlinear constraints whereas the failure probability of cumulative fatigue damage is viewed as an optimization objective. The results show that the dynamics performances of the hydraulic pipelines system are distinctly improved by the optimization procedure, such as, the maximum displacement and velocity are reduced by 67.5% and 58.6%, respectively, and the maximum axial stress and strain are both decral stress and strain are both decreased by 61.5% while the maximum shear stress and strain are reduced by 66.1%, and the failure probability of the first passage and cumulative fatigue damage are allayed by more than 99%, etc.

314

Utilization of a hydraulic barrier to control migration of a uranium plume  

International Nuclear Information System (INIS)

A uranium plume emanating from the U.S. Department of Energy's Fernald Environmental Management Project (FEMP) in Fernald, Ohio had migrated off site and the leading edge of the plume had already mixed with an organic and inorganic plume emanating from two industries south of the FEMP. A method was needed to prevent the further southern migration of the plume, minimize any impacts to the geometry, concentrations, distribution or flow patterns of the organic and inorganic plumes emanating from the off-site industries, while meeting the ultimate cleanup goals for the FEMP. This paper discusses the use of a hydraulic barrier created to meet these goals by pumping a five well recovery system and the problems associated with the disposition of over 2 million gallons per day of water with low concentrations of uranium

315

Scaling philosophy and system description of AHWR Thermal-Hydraulic Test Facility (ATTF)  

International Nuclear Information System (INIS)

The Advanced Heavy Water Reactor (AHWR) being designed in India is a 920 MWth pressure tube type boiling light water cooled and heavy water moderated reactor. AHWR Thermal Hydraulic Test Facility (ATTF), a scaled experimental facility that simulates the thermal-hydraulic behaviour of main heat transport system and ECCS, is designed. The objectives of the facility are to obtain thermal margin (CHF) and the parallel channel stability behaviour Global scaling is based on Power to Volume ratio. This philosophy is based on maintaining the same pressure, temperature with same working fluid. Main advantage of this scaling approach is that it preserves the time scales which are very crucial for the simulation of transient and accident conditions to assess the performance of safety systems. All of the Main Heat Transport (MHT) and Emergency Core Cooling System (ECCS) components are scaled down on the basis of power to volume scaling. ATTF contains two full power channels in comparison with 452 channels of AHWR then the scaling ratio is 226. Therefore the volumes of the components in natural circulation path (MHT) are scaled down by 226. Different local phenomenon like Critical Heat Flux (CHF), Flashing, Geysering etc which affects the performance of the system are scaled down appropriately. GDCS injection, feed water flow etc are simulated as boundary flow scaling approach. This 3-level approach simulates almost all the thermal hydraulics phenomenon of the prototype in the model, with the appropriate scale of the model to the prototype. (author)

316

A Study on Mission Profile and Determination of Durability Test Parameters in the Hydraulic Clutch System  

International Nuclear Information System (INIS)

One of reliability measurements of vehicle is estimated by driving mileage but the reliability of component, such as an hydraulic clutch system, is defined from the number of successful operational cycle. Relationship between these reliability measurement variables(mileage and cycle) should be examined first of all in the reliability estimation of components. Relationship between mileage and cycles is commonly known as linear function. However, the gradient depends on the operational environmental condition. Therefore, estimation of mission profile variable should be done with correlation analysis at the same time. In this paper, we derive mission profile variable of an hydraulic clutch system by field vehicle test and suggest the determination process of durability test parameters of CMC(Clutch Master Cylinder) with mission profile variable

317

Design of Instrumentation and Control System for ATLAS  

International Nuclear Information System (INIS)

The ATLAS(Advanced Thermal-hydraulic Test Loop for Accident Simulation) facility, which is a 1/2-height, 1/288-volume scaled and full-pressure test facility, has recently been constructed under the thermal-hydraulic integral effect test program by KAERI(Korea Atomic Energy Research Institute). The ATLAS consists of a reactor vessel and a core simulator, two steam generators, a pressurizer, four main coolant pumps, the related reactor coolant system (RCS) piping, safety injection systems, and secondary system and auxiliary systems. This paper introduces the instrumentation and control system of the ATLAS facility. The operation procedure, control logics and transient test scenarios have been developed to use the analysis result analyzed by a multi-dimensional best estimate thermal hydraulic code MARS 3.0

318

PLC based control system for RAM assembly test facility  

International Nuclear Information System (INIS)

The flexibility, expandability, ease of programming and diagnostic features makes the programmable logic controller (PLC) suitable for a variety of control applications in engineering system test facilities. A PLC based control system for RAM assembly test facility (RATF) and for testing the related hydraulic components is being developed and installed at BARC. This paper describes the approach taken for meeting the control requirements and illustrates the PLC software that has been developed. (author). 1 fig

319

Development of system hydraulic analytical GETR (SHAG) model used for analyzing incidences of loss of flow  

International Nuclear Information System (INIS)

A hydraulic model of the General Electric Test Reactor (GETR) primary system is described. This computer model (SHAG) simulates loss-of-flow events and calculates the flows as a function of time through the core, the pump, and the emergency cooling valves. By adjusting several free parameters, the prediction is made to satisfactorily agree with experimental data during the various stages of the transient

320

Porteau: An Object-Oriented programming hydraulic toolkit for water distribution system analysis  

OpenAIRE

Several computer tools exist for Water Distribution Systems Analysis. The most well known of which Epanet will not be maintained in the near future. To remedy this, open source development projects have recently been proposed. Cemagref have developed the Porteau software, with several tools. They have decided to make their software open and freely available. In this paper, we present our experience to design a hydraulic toolkit for Water Distribution Analysis which could benefit the commun...

Piller, O.; Gilbert, D.; Haddane, K.; Sabatie?, S.

2011-01-01

321

Modeling and Simulation of an Active Hydraulic Heave Compensation System for Offshore Cranes  

OpenAIRE

This thesis deals with the mathematical modeling of hydraulic heave compensation systems. When performing operations such as launch and recovery of remote operated vehicles and lowering subsea installation parts to the sea floor, it is important to attenuate unwanted load motion caused by elongation of the cable and heave motion of the vessel. Quite often, such operations must be put off while waiting for the weather to calm down. Extending the window of operations by developing equipme...

Sverdrup-thygeson, Jørgen

2007-01-01

322

Thermal Hydraulic numerical analysis of Fusion superconducting magnet systems  

OpenAIRE

In the present scenario, the International Thermonuclear Experimental Reactor (ITER) is in progress and efforts are being made to extend ITER to DEMOnstration Power plant (DEMO) with the purpose to harness the fusion energy for peaceful and constructive purposes. ITER uses the sueperconducting magnet systems for trapping and maneuvering plasma inside the giant tokamak machines. Superconductivity only entails under the critical conditions of temperature, magnetic field and current density. If ...

Kholia, Akshat

2013-01-01

323

Study of transient hydraulic in the essential service water system in NPP. Cofrentes  

International Nuclear Information System (INIS)

The present paper presents the study of the possible transient hydraulic that they could occur in the essential service water system due to changes in modes of operation, as well as replacement of components or failure of these within the same operating mode. For a complete analysis, it has created a computer model of the system through software EcosimPro, whereby different models have been corresponding to each division's system, making the check that in any mode of operation, and in any event, the values be exceeded the design for the system and its components.

324

Thermal–hydraulic system study of the HELOKA-LP helium loop using RELAP5-3D code  

Energy Technology Data Exchange (ETDEWEB)

Highlights: • Thermal–hydraulic system study for the HELOKA-LP using RELAP5-3D. • Validation of various experiments with corresponding simulations, and good comparison between the experiments and the simulations. • Simulation of the two most heated compartments of IFMIF HFTM in the modeled helium loop and prediction of the loop dynamic. -- Abstract: The thermal–hydraulic system analyses for the HELOKA-LP (Helium Loop Karlsruhe – Low Pressure) facility are presented. Typical operation ranges for the test section are mass flow rate between 12 and 120 g/s, inlet temperature between 10 and 250 °C and pressure level between 0.3 and 0.6 MPa. An orifice is used for the loop testing, for which different experiments are validated with appropriate simulations. Afterwards instead of the orifice, two most heated compartments of IFMIF (International Fusion Materials Irradiation Facility) HFTM (high flux test module) are simulated in HELOKA-LP. Using the system code REALP5-3D components in the loop are modeled as well as the main control strategy. With this model the loop dynamics in conditions relevant for the HFTM operation are analyzed and the thermal time constant of the compartment is estimated.

Jin, Xue Zhou, E-mail: jin@kit.edu; Schlindwein, Georg; Schlenker, Markus; Ghidersa, Bradut-Eugen; Chen, Yuming; Arbeiter, Frederik

2013-10-15

325

Thermal–hydraulic system study of the HELOKA-LP helium loop using RELAP5-3D code  

International Nuclear Information System (INIS)

Highlights: • Thermal–hydraulic system study for the HELOKA-LP using RELAP5-3D. • Validation of various experiments with corresponding simulations, and good comparison between the experiments and the simulations. • Simulation of the two most heated compartments of IFMIF HFTM in the modeled helium loop and prediction of the loop dynamic. -- Abstract: The thermal–hydraulic system analyses for the HELOKA-LP (Helium Loop Karlsruhe – Low Pressure) facility are presented. Typical operation ranges for the test section are mass flow rate between 12 and 120 g/s, inlet temperature between 10 and 250 °C and pressure level between 0.3 and 0.6 MPa. An orifice is used for the loop testing, for which different experiments are validated with appropriate simulations. Afterwards instead of the orifice, two most heated compartments of IFMIF (International Fusion Materials Irradiation Facility) HFTM (high flux test module) are simulated in HELOKA-LP. Using the system code REALP5-3D components in the loop are modeled as well as the main control strategy. With this model the loop dynamics in conditions relevant for the HFTM operation are analyzed and the thermal time constant of the compartment is estimated

326

Validation of Divertor Cassette locking system with a hydraulic jack tool  

International Nuclear Information System (INIS)

The divertor area of ITER vacuum vessel consists of 54 modular cassettes which must be exchanged after every 3-4 years of plasma operations. Divertor Cassettes are locked in the vacuum vessel by means of compressing them against the rails mounted in the inner and outer walls of the vacuum vessel. According to ITER reference cassette locking system, a Divertor Cassette has to be preloaded with a compression force of 360 kN against the vacuum vessel rails. The preloading of the cassettes is carried out with a hydraulic jack tool which is fitted into the cassette body. The Jack will transmit a hydraulic force by pushing the cassette latches against the outer rails, transmitting therefore the required preloading compression force to the cassette. This paper deals with the validation of Divertor Cassette locking system and it also describes the design and testing of a radiation-hard, water hydraulic jack. The validation of Divertor Cassette locking system has been the first Divertor Maintenance operation tested at Divertor Test Platform 2.

327

Validation of Divertor Cassette locking system with a hydraulic jack tool  

Energy Technology Data Exchange (ETDEWEB)

The divertor area of ITER vacuum vessel consists of 54 modular cassettes which must be exchanged after every 3-4 years of plasma operations. Divertor Cassettes are locked in the vacuum vessel by means of compressing them against the rails mounted in the inner and outer walls of the vacuum vessel. According to ITER reference cassette locking system, a Divertor Cassette has to be preloaded with a compression force of 360 kN against the vacuum vessel rails. The preloading of the cassettes is carried out with a hydraulic jack tool which is fitted into the cassette body. The Jack will transmit a hydraulic force by pushing the cassette latches against the outer rails, transmitting therefore the required preloading compression force to the cassette. This paper deals with the validation of Divertor Cassette locking system and it also describes the design and testing of a radiation-hard, water hydraulic jack. The validation of Divertor Cassette locking system has been the first Divertor Maintenance operation tested at Divertor Test Platform 2.

Takalo, Ville [Tampere University of Technology, Korkeakoulunkatu 6, 33720 Tampere (Finland)], E-mail: ville.takalo@tut.fi; Esque, Salvador; Mattila, Jouni; Vilenius, Matti [Tampere University of Technology, Korkeakoulunkatu 6, 33720 Tampere (Finland); Jaervenpaeae, Jorma; Siuko, Mikko [VTT Systems Engineering, Tekniikankatu 1, 33720 Tampere (Finland); Semeraro, Luigi; Irving, Mike; Damiani, Carlo [Fusion for Energy, Josep Pla 2, Torres Diagonal Litoral B3, 08019 Barcelona (Spain)

2009-06-15

328

Taenia eggs in a stabilization pond system with poor hydraulics: concern for human cysticercosis?  

Science.gov (United States)

The objective of this study is to compare the removal of Taenia eggs to the removal of Ascaris eggs in a wastewater stabilization pond system consisting of three ponds in series, where the hydraulic residence time distribution has been characterized via a tracer study supported by computational fluid dynamics modeling. Despite a theoretical hydraulic retention time of 30 days, the peak dye concentration was measured in the effluent of the first pond after only 26 hours. The smaller-sized Taenia eggs were detected in higher concentrations than Ascaris eggs in the raw wastewater. Ascaris eggs were not detected in the pond system effluent, but 45 Taenia eggs/L were detected in the system effluent. If some of these eggs were of the species Taenia solium, and if the treated wastewater were used for the irrigation of crops for human consumption, farmers and consumers could potentially be at risk for neurocysticercosis. Thus, limits for Taenia eggs in irrigation water should be established, and precautions should be taken in regions where pig taeniasis is endemic. The results of this study indicate that the theoretical hydraulic retention time (volume/flow) of a pond is not always a good surrogate for helminth egg removal. PMID:24355860

Verbyla, Matthew E; Oakley, Stewart M; Lizima, Louis A; Zhang, Jie; Iriarte, Mercedes; Tejada-Martinez, Andres E; Mihelcic, James R

2013-01-01

329

The development of control systems for high power steam turbines  

International Nuclear Information System (INIS)

The functional and technological aspects of developments in the field of control systems for steam turbines over the last twenty years are analyzed. These developments have now culminated in very sophisticated systems which closely link electronics to high pressure hydraulic technology. A detailed description of these systeme high-lighting the high technical level of the control methods and the flexibility and reliability in service of turbines controlled in this way is given

330

Accelerator control systems  

International Nuclear Information System (INIS)

These proceedings contain the articles presented at the named workshop. These concern existing accelerator control systems, the architecture of control systems, control systems for diagnostics, man/machine interfaces, modeling, network equipment interfaces, software development, and data bases for remote control. See hints under the relevant topics. (HSI)

331

Thermal-hydraulic characteristics of safety systems of advanced reactors  

International Nuclear Information System (INIS)

The heat transfer rates that occur inside and outside surfaces of the passive containment cooling system with both dry and wet outer containment surface following a postulated accident were investigated. The test model represented a 60 section of a containment vessel based on the AP600 geometry. The natural convective heat transfer from the containment to the air without water film flow was exceeded the expected values. Water film flow for the containment cooling is very effective to maintain the integrity of the structure of containment during postulated accident the local heat removal rate at the top of the dome is significantly higher than the average removal rate. (Author)

332

COMPARISON OF GENETIC FUZZY SYSTEM AND NEURO FUZZY SYSTEM FOR THE SELECTION OF OIL WELLS FOR HYDRAULIC FRACTURING  

Directory of Open Access Journals (Sweden)

Full Text Available The hydraulic fracture operation is wide used to increase the oil wells production and to reduce formation damage. Reservoir studies and engineer analysis are made to select the wells for this kind of operation. As the reservoir parameters have some diffuses characteristics, Fuzzy Inference Systems (SIF have been tested for this selection processes in the last few years. This paper compares the performance of a neuro fuzzy system and a genetic fuzzy system used for hydraulic Fracture well selection, with knowledge acquisition from an operational data base to set the SIF membership functions. The training data and the validation data used were the same for both systems. We concluded that, in despite of the genetic fuzzy system would be a younger process, it got better results than the neuro fuzzy system. Another conclusion was that, as the genetic fuzzy system can work with constraints, the membership functions setting kept the consistency of variables linguistic values.

Antônio Orestes de Salvo Castro

2007-06-01

333

Influence of geometrical and thermal hydraulic parameters on the short term containment system response  

International Nuclear Information System (INIS)

This paper discusses the effect of a number of geometrical and thermal hydraulic parameters on the containment peak pressure following a simulated LOCA. The numerical studies are carried out using an inhouse containment thermal hydraulics program called 'THYCON' with focus only on the short term transient response. In order to highlight the effect of above variables, a geometrically scaled (1:270) model of a typical 220 MWe Indian PHWR containment is considered. The discussions in this paper are limited to explaining the influence of individual parameters by comparing with a base case value. It is essential to mention that the results presented here are not general and should be taken as indicative only. Nevertheless, these numerical studies give insight into short term containment response that would be useful to both the system designer as well as the regulator. (author)

334

Methodology for comparison of hydraulic and thermal performance of alternative heat transfer fluids in complex systems  

Energy Technology Data Exchange (ETDEWEB)

A general method for the comparison of hydraulic and thermal performance of different liquid coolants in complex systems is offered. As a case study, the performance of polyalphaolefin (PAO) and a silicate ester-based fluid (Coolanol 25R) used as liquid coolants in avionic systems is presented. Thermophysical property expressions for the variation of density, specific heat, thermal conductivity, and kinematic viscosity with temperature for PAO and Coolanol 25R were developed. The range of temperature for this study was from {minus}54 to 135 C. Based on the results, the hydraulic performance of Coolanol 25R is much better than that of PAO at low temperatures (below 0 C) and in the laminar flow regime. In the turbulent region, PAO outperforms Coolanol 25R hydraulically over the entire temperature range. The thermal performance of PAO at temperatures below 61 C and in the laminar flow region is slightly better than that of Coolanol 25R. In the low-temperature turbulent region, Coolanol 25R outperforms PAO thermally. At other temperatures, the performance of the two liquid coolants is reasonably close and fairly independent of the flow regime.

Ghajar, A.J.; Tang, W.C. [Oklahoma State Univ., Stillwater, OK (United States). School of Mechanical and Aerospace Engineering; Beam, J.E. [Power Technology Branch, Wright Patterson AFB, OH (United States). Thermal Technology Section

1995-01-01

335

The neutron kinetics and thermal-hydraulic transient computational module of the NEPTUNE system: CRONOS  

International Nuclear Information System (INIS)

The NEPTUNE system had been designed to provide all the computational modules needed for a PWR calculation including design fuel management and reactivity accidents. The most recently added module is devoted to steady and transient calculations needing coupled neutronics and thermal-hydraulics calculations: it is named CRONOS. CRONOS accounts for detailed transient calculations: at each time step the moderator density and the fuel temperature are determined by a refined thermal-hydraulic calculation; these parameters are used as feed-back in the neutron-kinetics equations. The treatment of the 3D space dependent kinetics equation is based on the finite element method. This paper is divided into four parts: Part. 1 presents the finite element treatment of the neutron kinetics equation. Part. 2 is devoted to the thermal-hydraulic model implemented in Flica 3 and to the numerical treatment. Part. 3 briefly describes the ARIANE data processing system specially designed for NEPTUNE and in the last part numerical results are presented for a full size rod ejection calculation for a 900 Mwe PWR (Fessenheim 2)

336

Metallic particles into mechanical and hydraulic systems in agricultural and construction machines  

Energy Technology Data Exchange (ETDEWEB)

The lubricant oil analysis are an indicator of the conditions how the lubricant is, may to allow the prevision of damages that occurred into machine due to the internal abrasion of hydraulic and mechanical components of the machines. The present study had the objective to determine the kind and quantity of the metallic particles that occurred into the lubricant oil of the mechanical and hydraulic compartments of the energy transmission systems of three kinds of machines: a tracked-tractor, a sugarcane harvester and a group of power-shovels. The metallic particles presents into these compartments were determined under laboratory tests and concerning to the following elements: iron, copper, chromium, lead, nickel, aluminum, silex, tin and molybdenum. About to the tracked-tractor, the metallic contaminators into to the oil charges surpasses the tolerate levels, considering the technical standards adopted in this evaluation. In the sugarcane harvester only a metallic element in excess was identified and, in a power-shovel group it was showed the need to correct air false entrances in the hydraulic or mechanical systems due the high presence of silex element. (author)

Silva, Jair Rosas da; Silva, Deise Paula da [Instituto Agronomico de Campinas (IAC), Campinas, SP (Brazil). Centro de Engenharia Agricola; Bormio, Marcos Roberto [Universidade Estadual Paulista (UNESP), Bauru, SP (Brazil). Fac. de Engenharia

2008-07-01

337

Design and Development of Double Wishbone Electro-Hydraulic Active Suspension System  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract : This paper is a literature survey for the electro Design and development of Double electro-hydraulic active suspension system. It is divided into three section viz. literature survey, methodology adapted and design procedure and experimentation. In literature survey. we find the theoretical information regarding the various suspension systems, performance and find the way of work. Methodology consist of different part of systems like spring, drive pinion, rack, helical cam, follower pin and push rod. Design and Experimental result to evaluate Performance of prepared model it is placed over exciter and variable load is applied over it through strut arrangement.

Mr. K. S. Patil, Prof.V. R. Gambhire

2014-06-01

338

Software Tool for Automated Failure Modes and Effects Analysis (FMEA) of Hydraulic Systems  

DEFF Research Database (Denmark)

Offshore, marine,aircraft and other complex engineering systems operate in harsh environmental and operational conditions and must meet stringent requirements of reliability, safety and maintability. To reduce the hight costs of development of new systems in these fields improved the design management techniques and a vast array of computer aided techniques are applied during design and testing stages. The paper present and discusses the research and development of a software tool for automated failure mode and effects analysis - FMEA - of hydraulic systems. The paper explains the underlying principles of the software during operation, and provides a description of the software.

Stecki, J. S.; Conrad, Finn

2002-01-01

339

Interaction between thermal/hydraulics, human factors and system analysis for assessing feed and bleed risk benefits  

International Nuclear Information System (INIS)

For probabilistic analysis of accident sequences, thermal/hydraulics, human factors and systems operation problems are frequently closely interrelated. This presentation will discuss a typical example which illustrates this interrelation: total loss of feedwater flow. It will present thermal/hydraulic analysises performed, how the T/H analysises are related to human factors and systems operation, and how, based on this, the failure probability of the feed and bleed cooling mode was evaluated

340

Resolution of thermal-hydraulic safety and licensing issues for the system 80+trademark design  

International Nuclear Information System (INIS)

The System 80+trademark Standard Design is an evolutionary Advanced Light Water Reactor (ALWR) with a generating capacity of 3931 MWt (1350 MWe). The Final Design Approval (FDA) for this design was issued by the Nuclear Regulatory Commission (NRC) in July 1994. The design certification by the NRC is anticipated by the end of 1995 or early 1996. NRC review of the System 80+ design has involved several new safety issues never before addressed in a regulatory atmosphere. In addition, conformance with the Electric Power Research Institute (EPRI) ALWR Utility Requirements Document (URD) required that the System 80+ plant address nuclear industry concerns with regard to design, construction, operation and maintenance of nuclear power plants. A large number of these issues/concerns deals with previously unresolved generic thermal-hydraulic safety issues and severe accident prevention and mitigation. This paper discusses the thermal-hydraulic analyses and evaluations performed for the System 80+ design to resolve safety and licensing issues relevant to both the Nuclear Stream Supply System (NSSS) and containment designs. For the NSSS design, the Safety Depressurization System mitigation capability and resolution of the boron dilution concern are described. Examples of containment design issues dealing with containment shell strength, robustness of the reactor cavity walls and hydrogen mixing under severe accident conditions are also provided. Finally, the overall approach used in the application of NRC's new (NUREG-1465) radiological source term for System 80+ evaluation is described. The robustness of the System 80+ containment design to withstand severe accident consequences was demonstrated through detailed thermal-hydraulic analyses and evaluations. This advanced design to shown to meet NRC severe accident policy goals and ALWR URD requirements without any special design features and unnecessary costs

341

Resolution of thermal-hydraulic safety and licensing issues for the system 80+{sup {trademark}} design  

Energy Technology Data Exchange (ETDEWEB)

The System 80+{sup {trademark}} Standard Design is an evolutionary Advanced Light Water Reactor (ALWR) with a generating capacity of 3931 MWt (1350 MWe). The Final Design Approval (FDA) for this design was issued by the Nuclear Regulatory Commission (NRC) in July 1994. The design certification by the NRC is anticipated by the end of 1995 or early 1996. NRC review of the System 80+ design has involved several new safety issues never before addressed in a regulatory atmosphere. In addition, conformance with the Electric Power Research Institute (EPRI) ALWR Utility Requirements Document (URD) required that the System 80+ plant address nuclear industry concerns with regard to design, construction, operation and maintenance of nuclear power plants. A large number of these issues/concerns deals with previously unresolved generic thermal-hydraulic safety issues and severe accident prevention and mitigation. This paper discusses the thermal-hydraulic analyses and evaluations performed for the System 80+ design to resolve safety and licensing issues relevant to both the Nuclear Stream Supply System (NSSS) and containment designs. For the NSSS design, the Safety Depressurization System mitigation capability and resolution of the boron dilution concern are described. Examples of containment design issues dealing with containment shell strength, robustness of the reactor cavity walls and hydrogen mixing under severe accident conditions are also provided. Finally, the overall approach used in the application of NRC`s new (NUREG-1465) radiological source term for System 80+ evaluation is described. The robustness of the System 80+ containment design to withstand severe accident consequences was demonstrated through detailed thermal-hydraulic analyses and evaluations. This advanced design to shown to meet NRC severe accident policy goals and ALWR URD requirements without any special design features and unnecessary costs.

Carpentino, S.E.; Ritterbusch, S.E.; Schneider, R.E. [ABB-Combustion Engineering, Windsor, CT (United States)] [and others

1995-09-01

342

Development of a computational system for coupled neutronic, thermal-hydraulic and structural analysis using message passing interface  

International Nuclear Information System (INIS)

A prototype computational system for simulating coupled neutronic, thermal-hydraulic, and structural behaviors in a liquid-metal fast reactor (LMFR) core has been developed for the ultimate purpose of establishing an environment of numerical experiments, where one can virtually experience and observe complex physical phenomena occurring in a fast reactor core. The system takes into consideration the distortion of power density distribution and reactivity feedback due to core deformation, which reflects the change of coolant temperature through various reactivity feedback effects. It was also attempted to minimize data communication time among the coupled codes and the large work loads for maintenance. Instead of the conventional way of importing and exporting data files, a specific message passing library is used for the efficient data communication between analysis codes. This system consists of ; four existing large-scale codes, which analyze reactor core characteristics, reactivity worth based on perturbation theory, plant dynamics and core deformation ; interface modules for data transfer between the codes ; and a master program for control of the system. In addition, the connection between these four codes by two interface programs allows us to update the system easily when a physical model in each code has to be modified. To demonstrate the applicability and usefulness of the system, a series of calculations were attempted for simulating a sequence of a hypotheted for simulating a sequence of a hypothetical loss of heat sink in an LMFR. It was shown that the reactor core analysis system developed in this study can adequately simulate coupled neutronic, thermal-hydraulic and structural phenomena with both reasonable computational time and small loads required to update the system. (author)

343

ISABELLE control system  

International Nuclear Information System (INIS)

Design principles for the Brookhaven ISABELLE control intersecting storage ring accelerator are described. Principal features include a locally networked console and control computer complex, a system wide process data highway, and intelligent local device controllers. Progress to date is summarized

344

CRAB-II: a computer program to predict hydraulics and scram dynamics of LMFBR control assemblies and its validation  

International Nuclear Information System (INIS)

This paper presents an analytical method, the computer code CRAB-II, which calculates the hydraulics and scram dynamics of LMFBR control assemblies of the rod bundle type and its validation against prototypic data obtained for the Clinch River Breeder Reactor (CRBR) primary control assemblies. The physical-mathematical model of the code is presented, followed by a description of the testing of prototypic CRBR control assemblies in water and sodium to characterize, respectively, their hydraulic and scram dynamics behavior. Comparison of code predictions against the experimental data are presened in detail; excellent agreement was found. Also reported are experimental data and empirical correlations for the friction factor of the absorber bundle in the entire flow range (laminar to turbulent) which represent an extension of the state-of-the-art, since only fuel and blanket assemblies friction factor correlations were previously reported in the open literature

345

Control and automation systems  

International Nuclear Information System (INIS)

A survey is given of the development of control and automation systems for energy uses. General remarks about control and automation schemes are followed by a description of modern process control systems along with process control processes as such. After discussing the particular process control requirements of nuclear power plants the paper deals with the reliability and availability of process control systems and refers to computerized simulation processes. The subsequent paragraphs are dedicated to descriptions of the operating floor, ergonomic conditions, existing systems, flue gas desulfurization systems, the electromagnetic influences on digital circuits as well as of light wave uses. (HAG)

346

The remote control system  

International Nuclear Information System (INIS)

The remote-control system is applied in order to control various signals in the car of the spectrometer at distance. The construction (hardware and software) as well as the operation of the system is described. (author). 20 figs

347

Identification and real-time position control of a servo-hydraulic rotary actuator by means of a neurobiologically motivated algorithm.  

Science.gov (United States)

This paper presents a new intelligent approach for adaptive control of a nonlinear dynamic system. A modified version of the brain emotional learning based intelligent controller (BELBIC), a bio-inspired algorithm based upon a computational model of emotional learning which occurs in the amygdala, is utilized for position controlling a real laboratorial rotary electro-hydraulic servo (EHS) system. EHS systems are known to be nonlinear and non-smooth due to many factors such as leakage, friction, hysteresis, null shift, saturation, dead zone, and especially fluid flow expression through the servo valve. The large value of these factors can easily influence the control performance in the presence of a poor design. In this paper, a mathematical model of the EHS system is derived, and then the parameters of the model are identified using the recursive least squares method. In the next step, a BELBIC is designed based on this dynamic model and utilized to control the real laboratorial EHS system. To prove the effectiveness of the modified BELBIC's online learning ability in reducing the overall tracking error, results have been compared to those obtained from an optimal PID controller, an auto-tuned fuzzy PI controller (ATFPIC), and a neural network predictive controller (NNPC) under similar circumstances. The results demonstrate not only excellent improvement in control action, but also less energy consumption. PMID:22015061

Sadeghieh, Ali; Sazgar, Hadi; Goodarzi, Kamyar; Lucas, Caro

2012-01-01

348

Modeling and Simulation of Valve-controlled Cylinder System Based on Bond Graph  

Directory of Open Access Journals (Sweden)

Full Text Available AMESim is a high performance modeling, simulation and dynamic analysis software. Based on the bond graph theory and the principle of hydraulic control, a simulation model of valve-controlled cylinder system in EPS fatigue testing bench is established by using AMESim software. By changing different factors of the hydraulic system and setting different target wave curves, the system effects with different conditions are discussed and the simulation results provide a theoretical guidance for modeling optimization.

Wang Qi

2012-08-01

349

Development of core thermal-hydraulics module for intelligent reactor design system (IRDS)  

International Nuclear Information System (INIS)

We have developed an innovative reactor core thermal-hydraulics module where a designer can easily and efficiently evaluate his design concept of a new type reactor in the thermal-hydraulics field. The main purpose of this module is to decide a feasible range of basic design parameters of a reactor core in a conceptual design stage of a new type reactor. The module is to be implemented in Intelligent Reactor Design System (IRDS). The module has the following characteristics; 1) to deal with several reactor types, 2) four thermal hydraulics and fuel behavior analysis codes are installed to treat different type of reactors and design detail, 3) to follow flexibly modification of a reactor concept, 4) to provide analysis results in an understandable way so that a designer can easily evaluate feasibility of his concept, and so on. The module runs on an engineering workstation (EWS) and has a user-friendly man-machine interface on a pre- and post-processing. And it is equipped with a function to search a feasible range called as Design Window, for two design parameters by artificial intelligence (AI) technique and knowledge engineering. In this report, structure, guidance for users of an usage of the module and instruction of input data for analysis modules are presented. (author)

350

Engineering solutions and thermal hydraulic issues for a promising safe ADS system  

International Nuclear Information System (INIS)

European leading nuclear Industrial Companies and Research Centres have studied three concepts of Accelerator Driven System, in the frame of the Fifth Framework Programme of the EU: a 80 MW LBE-Cooled ADS, a 80 MW Gas-Cooled ADS, a smaller 50MW LBE-Cooled ADS. The paper describes the status of development of the 80 MW LBE-cooled experimental ADS and analyzes its advantages and limits. The XADS design has demonstrated the possibility of a safe coupling of a subcritical rector with an accelerator. The prospective activity will include additional objectives like electric energy generation, cost minimization and effective minor actinides burning. The novelty of the heavy metal coolant and of the technical solutions of the XADS have required the study of peculiar thermal hydraulic aspects by means of codes not always adequate for the purpose. It is anticipated that the design modifications necessary to address the new objectives will present challenging technological, mechanical, thermal hydraulic, and safety issues. The paper makes a preliminary screening of those issue and focus on the need of adequate thermal hydraulic codes and models to obtain the information required by the designer for the development of the ADS. (author)

351

Design and Experimental Validation of Hydraulic Yaw System for Multi MW Wind Turbine  

DEFF Research Database (Denmark)

To comply with the increasing demands for life time and reliability of wind turbines as these grow in size, new measures needs to be taken in the design of wind turbines and components hereof. One critical point is the initial testing of the components and systems before they are implemented in an actual turbine. Full scale hardware testing is both extremely expensive and time consuming, and so the wind turbine industry moves more towards simulations when testing. In order to meet these demands it is necessary with valid models of systems in order to introduce new technologies to the wind turbine market. A hydraulic yaw system is such a new technology, and so a mathematical model of the full scale system and test rig system is derived and compared to measurements from the system. This is done in order to have a validated model, which wind turbine manufacturers may use for test in their simulation environment. The model and the test rig are tested up against different design load cases and the results are compared. The experiments show that the model is valid for comparing the overall dynamics of the hydraulic yaw system. Based on the results it is concluded that the model derived is suitable for testing of the dynamic behavior in wind turbine manufacturer’s full scale aero elastic code.

Stubkier, SØren; Pedersen, Henrik C.

2013-01-01

352

Clearing electrode control system  

International Nuclear Information System (INIS)

Due to the introduction of new high voltage power supplies in the clearing electrode system, a control system was built with improved remote controlled capability. This system is essentially a serial transmission network, allowing the control of 128 independent locations, 8 separate commands being possible in each station. Speed is rather low (about 100 commands per second) but noise immunity is high. (Auth.)

353

Thermal hydraulic performance of seawater desalination system using a nuclear heating reactor  

International Nuclear Information System (INIS)

A physical-mathematical model was developed to explore the thermal hydraulic performance of a vertical tube multi-effect distillation seawater desalination system coupled with the nuclear heating reactor. Two temperature difference distribution schemes, equal temperature difference and equal heat transfer area temperature difference, were used for the system design. The results indicate that the gain-output-ratio with both temperature difference distribution schemes can be up to 20. However, the design with the equal heat transfer area temperature difference is more suitable for a tower design. The results would be helpful for designing a large capacity vertical tube multi-effect distillation desalination plant

354

Fuzzy logic electric vehicle regenerative antiskid braking and traction control system  

Science.gov (United States)

An regenerative antiskid braking and traction control system using fuzzy logic for an electric or hybrid vehicle having a regenerative braking system operatively connected to an electric traction motor, and a separate hydraulic braking system includes sensors for monitoring present vehicle parameters and a processor, responsive to the sensors, for calculating vehicle parameters defining the vehicle behavior not directly measurable by the sensor and determining if regenerative antiskid braking control, requiring hydraulic braking control, and requiring traction control are required. The processor then employs fuzzy logic based on the determined vehicle state and provides command signals to a motor controller to control operation of the electric traction motor and to the brake controller to control fluid pressure applied at each vehicle wheel to provide the appropriate regenerative braking control, hydraulic braking control, and traction control.

Cikanek, Susan R. (Wixom, MI)

1994-01-01

355

Virtual Training System for Hydraulic Pump Cart Based on Virtual Reality  

Directory of Open Access Journals (Sweden)

Full Text Available This paper dissertates the application of Virtual Reality Technology in the training process. Virtual training system has more advantages than traditional training system. The design of virtual training system based on PTC DIVISION Mockup software, position tracker and 3-D mouse is proposed. The system is divided into two parts: directing part and operating part. Collision detection is discussed to improve the sense of reality in the virtual environment .This system is applied to the training process of hydraulic pump cart’s assembly and disassembly. More immersive training effect is obtained in this system. The goal of reducing training costs and improving the efficiency of training can be achieved in the virtual training system.  

Wusha Huang

2013-08-01

356

Analysis of the Power Head Torque Loading System Based on Hydraulic Energy Closed-loop  

Directory of Open Access Journals (Sweden)

Full Text Available Power head with high power and large torque is the main power equipment of the rotary drilling rig. Aimed at the working condition, energy saving torque loading test program of power head was put forward and mathematical and simulation models of hydraulic energy closed-loop torque loading system were established in order to make an analysis of torque loading system. Combined with bond graph and state equations of torque loading system with single pump, effect of the logical relationship of discharge between the driving motor and loading pump and the relationship between the adjusting proportion of series and parallel pressure on the torque loading system was analyzed because both hydraulic flow and pressure can have an influence on the system stability. It proves that the torque loading system is stable when the adjusting proportion of series pressure is larger than that of the parallel pressure. Otherwise, it needs to consider the discharge trend between the power motor and loading pump.

Xianjin Shi

2013-07-01

357

Control system model for the SASSYS-1 systems analysis code  

International Nuclear Information System (INIS)

A general control system model has been coupled with SASSYS-1 one-dimensional liquid-metal reactor (LMR) thermal-hydraulics code to provide an integrated treatment for LMRs similar to the general control system/thermal-hydraulics treatment available for light water reactors in RETRAN. With the development of innovative reactor design concepts, the emphasis on LMR safety has shifted away from the consideration of hypothetical whole-core disruptive accidents (HCDAs) to transients with much milder consequences and of much longer time scale. This increase in time scale, rendered possible by the incorporation of a number of inherently safe design features, makes it important to consider the possibility of control system action in the long-term response of the plant and to ascertain that inadvertent aggravation of the transient by control action is not possible. As a step in this direction, the Argonne National Laboratory (ANL) LMR system transient code SASSYS-1, which evolved from the ANL LMR HCDA code, SAS4A, was modified to include a control system simulation module

358

Stomatal control and hydraulic conductivity in 'Manzanilla' olive trees under different water regimes  

OpenAIRE

We studied the response of leaf water potential (?1), stomatal conductance (gs), leaf specific hydraulic conductivity (Kl) and percentage loss of hydraulic conductivity (PLC) in current-year shoots of 40-year-old 'Manzanilla' olive trees under three water treatments: Rainfed, in which rainfall was the only source of water; FAO, in which the trees were under localized irrigation to replace crop water demand; Pond, in which the whole root zone of the trees was maintained under non-limiting soi...

Torres Ruiz, Jose? Manuel; Ferna?ndez Luque, Jose? Enrique; Di?az-espejo, Antonio; Marti?n Palomo, Mª Jose?; Morales Sillero, Ana; Muriel Ferna?ndez, Jose? L.; Romero Vicente, Rafael

2011-01-01

359

Control Configuration Selection for Multivariable Descriptor Systems  

DEFF Research Database (Denmark)

Control configuration selection is the procedure of choosing the appropriate input and output pairs for the design of SISO (or block) controllers. This step is an important prerequisite for a successful industrial control strategy. In industrial practices it is often the case that the system, which is needed to be controlled, is either in the descriptor form or can be represented in the descriptor form. Singular systems and the differential algebraic equation (DAE) systems are among these systems. Descriptor systems appear in the variety of fields to describe the practical processes ranging from power systems, hydraulic systems to heat transfer, and chemical processes. The focus of this paper is on the problem of control configuration selection for multivariable descriptor systems. A gramian-based interaction measure for control configuration selection of such processes is described in this paper. The proposed MIMO interaction measure is the extension of its gramian-based analogous counterpart, which has been proposed for the input–output pairing as well as for the controller architecture selection of the processes with the standard state-space form. The main advantage of this interaction measure is that it can be used to propose a richer sparse or block diagonal controller structure. The interaction measure is used for control configuration selection of the linearized CSTR model with descriptor from.

Shaker, Hamid Reza; Stoustrup, Jakob

2012-01-01

360

MODLP program description: A program for solving linear optimal hydraulic control of groundwater contamination based on MODFLOW simulation. Version 1.0  

International Nuclear Information System (INIS)

MODLP is a computational tool that may help design capture zones for controlling the movement of contaminated groundwater. It creates and solves linear optimization programs that contain constraints on hydraulic head or head differences in a groundwater system. The groundwater domain is represented by USGS MODFLOW groundwater flow simulation model. This document describes the general structure of the computer program, MODLP, the types of constraints that may be imposed, detailed input instructions, interpretation of the output, and the interaction with the MODFLOW simulation kernel

361

Improvement of Hydraulic and Water Quality Renovation Functions by Intermittent Aeration of Soil Treatment Areas in Onsite Wastewater Treatment Systems  

OpenAIRE

We tested intermittent aeration of the soil treatment area (STA) of onsite wastewater treatment systems (OWTS) for its ability to restore and maintain STA hydraulic flow and improve the water quality functions of conventional OWTS. Evaluation was conducted on hydraulically-failed conventional OWTS at three state-owned medical group homes in Washington County, RI, USA. Testing was conducted in two phases, with Phase I (before intermittent soil aeration (ISA)) comprising the first 6 months of t...

Kalen, David V.; Go?rres, Josef H.; Patenaude, Erika L.; Potts, David A.; Loomis, George W.; Amador, Jose? A.

2010-01-01

362

Hydraulic Geometry, GIS and Remote Sensing, Techniques against Rainfall-Runoff Models for Estimating Flood Magnitude in Ephemeral Fluvial Systems  

OpenAIRE

This paper shows the combined use of remotely sensed data and hydraulic geometry methods as an alternative to rainfall-runoff models. Hydraulic geometric data and boolean images of water sheets obtained from satellite images after storm events were integrated in a Geographical Information System. Channel cross-sections were extracted from a high resolution Digital Terrain Model (DTM) and superimposed on the image cover to estimate the peak flow using HEC-RAS. The proposed methodology has been...

Rafael Garcia-Lorenzo; Sanchez Tomas, Juan M.; Vicente Caselles-Miralles; Carmelo Conesa-Garcia

2010-01-01

363

Numerical Hydraulic Study on Seawater Cooling System of Combined Cycle Power Plant  

Science.gov (United States)

As the rated flow and pressure increase in pumping facilities, a proper design against surges and severe cavitations in the pipeline system is required. Pressure surge due to start-up, shut-down process and operation failure causes the water hammer in upstream of the closing valve and the cavitational hammer in downstream of the valve. Typical cause of water hammer is the urgent closure of valves by breakdown of power supply and unexpected failure of pumps. The abrupt changes in the flow rate of the liquid results in high pressure surges in upstream of the valves, thus kinetic energy is transformed into potential energy which leads to the sudden increase of the pressure that is called as water hammer. Also, by the inertia, the liquid continues to flow downstream of the valve with initial speed. Accordingly, the pressure decreases and an expanding vapor bubble known as column separation are formed near the valve. In this research, the hydraulic study on the closed cooling water heat exchanger line, which is the one part of the power plant, is introduced. The whole power plant consists of 1,200 MW combined power plant and 220,000 m3/day desalination facility. Cooling water for the plant is supplied by sea water circulating system with a capacity of 29 m3/s. The primary focus is to verify the steady state hydraulic capacity of the system. The secondary is to quantify transient issues and solutions in the system. The circuit was modeled using a commercial software. The stable piping network was designed through the hydraulic studies using the simulation for the various scenarios.

Kim, J. Y.; Park, S. M.; Kim, J. H.; Kim, S. W.

2010-06-01

364

RBMK coupled neutronics/thermal-hydraulics analyses by two independent code systems  

International Nuclear Information System (INIS)

This paper presents the coupled neutronics/thermal-hydraulics activities carried out in the framework of the part B of the TACIS project R2.03/97, 'Software development for accident analysis of RBMK reactors in Russia'. Two independent code systems were assembled, one from the Russian side and the other from the Western side, for studying RBMK core transients. The Russian code system relies on the use of code UNK for neutron data libraries generation and the three-dimensional neutron kinetics thermal-hydraulics coupled codes BARS-KORSAR for plant transient analyses. The Western code system is instead based on the lattice physics code HELIOS and on the RELAP5-3D C code. Several activities were performed for testing code system's capabilities: the neutron data libraries were calculated and verified by precise Monte Carlo calculations, the coupled codes' steady state results were compared with plant detectors' data, and calculations of several transients were compared. Finally, both code systems proved to have all the capabilities for addressing reliable safety analyses of RBMK reactors. (authors)

365

Integrated control systems  

International Nuclear Information System (INIS)

This paper reports that instrument manufacturers must develop standard network interfaces to pull together interrelated systems such as automatic start-up, optimization programs, and online diagnostic systems. In the past individual control system manufacturers have developed their own data highways with proprietary hardware and software designs. In the future, electric utilities will require that future systems, irrespective of manufacturer, should be able to communicate with each other. Until now the manufactures of control systems have not agreed on the standard high-speed data highway system. Currently, the Electric Power Research Institute (EPRI), in conjunction with several electric utilities and equipment manufactures, is working on developing a standard protocol for communicating between various manufacturers' control systems. According to N. Michael of Sargent and Lundy, future control room designs will require that more of the control and display functions be accessible from the control room through CRTs. There will be less emphasis on traditional hard-wired control panels

366

The Control System Modeling and The Mechanical Structure Analysis For EMCVT  

Directory of Open Access Journals (Sweden)

Full Text Available The current automotive metallic belt continuously variable transmission (CVT mostly use hydraulic system to push the cone disc and achieve the speed ratio control. A new Electrical Mechanical Continuously Variable Transmission without hydraulic control (Electrical Mechanical CVT, EMCVT studied in this paper, uses the rolling screw mechanism to press cone disc, achieves speed regulation through the electronic control mechanism, and abandons the energy-intensive hydraulic system. In this paper, based on the analysis of mechanical configuration, the EMCVT's transmission system and its speed regulation process, speed ratio control characteristic and the clamping force control feature are studied and modeled. Besides, the Control strategy of the transmission system driven by motor is built, so as to provide an important theoretical basis for the further building of EMVCT's control system and the selection and implementation of Control strategy.

Lei ZHANG

2013-07-01

367

Adaptive fuzzy control for a simulation of hydraulic analogy of a nuclear reactor  

International Nuclear Information System (INIS)

In the framework of the on-going R and D project on fuzzy control applications to the Belgian Reactor 1 (BR1) at the Belgian Nuclear Research Centre (SCK-CEN), we have constructed a real fuzzy-logic-control demo model. The demo model is suitable for us to test and compare some new algorithms of fuzzy control and intelligent systems, which is advantageous because it is always difficult and time consuming, due to safety aspects, to do all experiments in a real nuclear environment. In this chapter, we first report briefly on the construction of the demo model, and then introduce the results of a fuzzy control, a proportional-integral-derivative (PID) control and an advanced fuzzy control, in which the advanced fuzzy control is a fuzzy control with an adaptive function that can self-regulate the fuzzy control rules. Afterwards, we present a comparative study of those three methods. The results have shown that fuzzy control has more advantages in terms of flexibility, robustness, and easily updated facilities with respect to the PID control of the demo model, but that PID control has much higher regulation resolution due to its integration terms. The adaptive fuzzy control can dynamically adjust the rule base, therefore it is more robust and suitable to those very uncertain occasions. (orig.)

368

Development on combined method of the thermo-hydraulic and structural analysis for the thermal transients at the heat transportation systems of FBR plant  

International Nuclear Information System (INIS)

By picking up a system thermal transition problem with large effects on economic efficiency of FBR plant, here were aimed at development on a combined method of thermo-hydraulic and structural analysis on one of vertical engineering technique and a new design method based on it. As system thermal transient load is affected by a number of factors at every levels of plant system, thermal flow, and structure, to rationally evaluate them it is necessary to improve an approach from a conventional method to supply and evaluate the thermo-hydraulic analysis results to structures on one-through to the combined method capable of properly evaluating the combination under considering degree of effects of every factors containing thermal flow on structural integrity. Therefore, here was carried out a trial analysis combining a thermo-hydraulic and structural analysis code with experimental programming method by establishing a concrete system thermal transition problem on FBR plant, to investigate applicability of the above-mentioned approach. As a result, it was found that by using the trial analysis, degree of efforts of every control factors on stress formed at system thermal transition could quantitatively be evaluated, and the trial analysis had better efficiency than that of conventional method and enabled to find the severest conditions to form stress. Here were arranged and showed some subjects forwards effective evaluation system construction applied by experimental progrconstruction applied by experimental programming method on a base of such investigation results. (G.K.)

369

Intelligent control systems 1990  

International Nuclear Information System (INIS)

The field of artificial intelligence (Al) has generated many useful ideas and techniques that can be integrated into the design of control systems. It is believed and, for special cases, has been demonstrated, that integration of Al into control systems would provide the necessary tools for solving many of the complex problems that present control techniques and Al algorithms are unable to do, individually. However, this integration requires the development of basic understanding and new fundamentals to provide scientific bases for achievement of its potential. This book presents an overview of some of the latest research studies in the area of intelligent control systems. These papers present techniques for formulation of intelligent control, and development of the rule-based control systems. Papers present applications of control systems in nuclear power plants and HVAC systems

370

TRACE Analysis for Transient Thermal-hydraulics of A Heavy Liquid Metal Cooled System  

OpenAIRE

Heavy liquid metal (HLM - lead or lead bismuth eutectic) is considered as a candidate coolant for next-generation fast reactor and accelerate-driven systems (ADS), due to its favorable chemical, thermo-physical and neutronic properties in comparison with sodium which has been used as coolant in fast breeder reactors (FBRs). To perform design-base-accident analysis for the HLM-cooled reactors, the well-known transient thermal-hydraulic analysis codes (e.g., RELAP5 and TRACE) are being applied ...

Shao, Yiqiong

2011-01-01

371

Thermal-hydraulic analysis of the combustion engineering system 80 steam generator. Final report  

International Nuclear Information System (INIS)

This report presents the results of a thermal-hydraulic analysis of the Combustion Engineering SYSTEM 80 recirculating-type steam generator using THIRST - a three-dimensional, steady state, incompressible, homogeneous, two-phase flow computer code. The analysis was done for operating conditions corresponding to 100%, 60% and 20% of the nominal full power. Results are presented in the form of detailed printouts and computer-generated plots of quality, velocity and mass flux distributions. The printout data include calculated values of overall heat transfer, circulation ratio, hot-side cold-side flow split, inlet temperature, as well as velocity, quality, temperature, pressure and density fields

372

Calculation of the thermal-hydraulic transient in multicompartment systems by ARIANNA computer codes  

International Nuclear Information System (INIS)

A research program on the behaviour of containment systems has been carried out for a long time at the ''Istituto di Impianti Nucleari'' of the University of Pisa (I.I.N. - Pisa), to set up a calculation model adequate for the analysis of the thermal-hydraulic transient following a LOCA. A computer code family, named Arianna, has been developed for this purpose. In order to verify and comprove ARIANNA's modelling, the I.I.N. - Pisa took part in the international exercises, sponsored by OECD - CSNI: Numerical Benchmark Problem; Containment Standard Problem (CASP) n. 1, 2 and 3

373

Thermal-hydraulics for space power, propulsion, and thermal management system design  

International Nuclear Information System (INIS)

The present volume discusses thermal-hydraulic aspects of current space projects, Space Station thermal management systems, the thermal design of the Space Station Free-Flying Platforms, the SP-100 Space Reactor Power System, advanced multi-MW space nuclear power concepts, chemical and electric propulsion systems, and such aspects of the Space Station two-phase thermal management system as its mechanical pumped loop and its capillary pumped loop's supporting technology. Also discussed are the startup thaw concept for the SP-100 Space Reactor Power System, calculational methods and experimental data for microgravity conditions, an isothermal gas-liquid flow at reduced gravity, low-gravity flow boiling, computations of Space Shuttle high pressure cryogenic turbopump ball bearing two-phase coolant flow, and reduced-gravity condensation

374

Elevator and hydraulics; Elevator to yuatsu  

Energy Technology Data Exchange (ETDEWEB)

A hydraulic type elevator is installed in relatively lower buildings as compared with a rope type elevator, but the ratio in the number of installation of the former elevator is increasing. This paper explains from its construction and features to especially various control systems for the riding comfort and safety. A direct push-up system with hydraulic jacks arranged beneath a car, and an indirect push-up system that has hydraulic jacks arranged on flank of a car and transmits the movement of a plunger via a rope are available. The latter system eliminates the need of large holes to embed hydraulic jacks. While the speed is controlled by controlling flow rates of high-pressure oil, the speed, position, acceleration and even time differential calculus of the acceleration must be controlled severely. The system uses two-step control for the through-speed and the landing speed. Different systems that have been realized may include compensation for temperatures in flow rate control valves, load pressures, and oil viscosity, from learning control to fuzzy control for psychological effects, or control of inverters in motors. 13 refs., 12 figs., 1 tab.

Nakamura, I. [Hitachi, Ltd., Tokyo (Japan)

1994-07-15

375

ALFA Detector Control System  

CERN Document Server

ALFA (Absolute Luminosity For ATLAS) is one of the sub-detectors of ATLAS/LHC. The ALFA system is composed by two stations installed in the LHC tunnel 240 m away from each side of the ATLAS interaction point. Each station has a vacuum and ventilation system, movement control and all the required electronic for signal processing. The Detector Control System (DCS) provides control and monitoring of several components and ensures the safe operation of the detector contributing to good Data Quality. This paper describes the ALFA DCS system including a detector overview, operation aspects and hardware control through a SCADA system, WinCC OA.

Oleiro Seabra, Luis Filipe; The ATLAS collaboration

2015-01-01

376

Discussion on sealing performance required in a disposal system. Preliminary study on hydraulic analysis of disposal panel  

International Nuclear Information System (INIS)

The sealing performance of a repository is very important for the safety assessment of the geological disposal system for high-level radioactive waste. NUMO and JAEA set up a technical commission to investigate sealing technology in a repository in 2004 following a cooperation agreement between these two organisations. The objectives of this commission were to present a concept of sealing performance required in the disposal system and to direct future R and D for design requirements of closure components (backfilling material, clay plug, etc.). Hydraulic analyses on tunnel intersections were carried out during the first year in 2004. This was expanded into a hydraulic analysis of a complete disposal panel with all tunnels during the second year in 2005. Since the model structure in 2005 was more complicated than the one used in 2004, the concept of equivalent permeability was adopted in and around each tunnel in the hydraulic analysis. Parameters used in the hydraulic analyses were installation positions of clay plugs, permeability of the backfilling material, permeability of disposal tunnel and directions of hydraulic gradient to estimate influences to the analytical results preliminary. Analytical results showed that flow rate in a disposal tunnel was influenced by directions of hydraulic gradient, installation of the clay plug at the both ends of each disposal tunnel and permeability of the main funnel. (author)

377

Thermal and hydraulic analysis of the cooling system for the ITER equatorial port plugs  

International Nuclear Information System (INIS)

Thermo-hydraulic analysis of the equatorial port plug (EPP) is currently being performed by CIEMAT within the framework of the engineering activities related to the ITER port plug diagnostic integration launched by EFDA. This study is focussed on calculating the main hydraulic parameters for the reference cooling circuit, and analyzing different piping configurations, in order to achieve a balanced circuit, this being a key point for obtaining an homogeneous refrigeration of the port plug. It also analyzes the cooling requirements for the Diagnostic Shield Modules (DSM), considering not only the reference circuit design, where the piping cooling circuits run through those parts that need to be cooled, but also a new design proposal which entails a port plug cooling system based on the thermal contact between the DSM and the port plug itself. The overall study represents not only an improvement in the equatorial port plug cooling system design, but also a better understanding of the whole system so as to foresee the weak points that will need to be taken into account in the subsequent detailed design.

378

CANTHIS, the CANDU neutronic and thermal hydraulic information system: Its development, structure and contents  

International Nuclear Information System (INIS)

This paper addresses the on-going procedures of the development of a database and its contents. The database named as CANTHIS (CANDU Neutronic and Thermal Hydraulic Information System) is originally designed under the technical basis of SQL (Structured Query Language) in order to help the CANDU-related researchers to easily and quickly find the experimental information, as a part of the CASA (CANDU Safety Analysis) project set about by KAERI (Korea Atomic Energy Research Institute). The database is mainly intended to produce thermal-hydraulic experimental data resulted from the CANDU-related facilities around the world and it also includes some neutronics data which are especially from some critical facilities related to CANDU. Because there are some limitations for getting the raw data from each experiment, the system generally gives information with the images of graphs come from literatures comprehensively including all kinds of papers available. As an additional function, CANTHIS offers a digitizing tool converting the images to numerical data. The CANTHIS also includes the useful menus and documents because we intended it to be used by the beginners or students in nuclear engineering field as well as by the specialists for CANDU safety analysis. With the supporting database system such as the CANTHIS, the efficiency of researches for CANDU safety analysis can be enhanced and systematized. (author)

379

Thermal-hydraulic analysis of three LOCA's in the divertor cooling system of NET/ITER  

International Nuclear Information System (INIS)

This report presents the thermal-hydraulic analysis of three Loss-of-Coolant Accidents (LOCA's) in the divertor cooling system of the Next European Torus (NET) or the International Thermonuclear Experimental Reactor (ITER). The analysis is based on the latest occupational design of the divertor cooling system. No plasma shutdown and no other counter-actions have been assumed in order to study the worst case conditions of the accidents. The following scenarios have been analyzed: 1. a large break LOCA initiated by a double-ended guillotine break in the cold leg; 2. an intermediate break LOCA initiated by a double-ended guillotine break in a feeder from the inlet ring collector to a sector manifold; 3. an intermediate break LOCA initiated by a double-ended guillotine break in the surge line of the pressurizer. All scenarios will finally result in melting of the divertor plates. The analyses have been performed using the thermal-hydraulic system analysis computer code RELAP5/MOD3. (author). 11 refs.; 63 figs.; 3 tabs

380

Dictionary of control technology. Pneumatics, hydraulics, electronics. English-German, German-English. Woerterbuch der Steuerungstechnik. Pneumatik, Hydraulik, Elektronik. Deutsch-Englisch, Englisch-Deutsch  

Energy Technology Data Exchange (ETDEWEB)

The English-German/German-English dictionary covers the complete field of control technology present in industry today. The subjects represent appropriate terms from hydraulics, pneumatics, electrical engineering, electronics, data processing, administration, and training. (DG).

Budd, F.

1988-01-01

381

PLS computer control system  

International Nuclear Information System (INIS)

Emphasizing reliability and flexibility, hierarchical architecture with distributed computers has been designed into the Pohang Light Source (PLS) computer control system. It has four layers of computer systems connected via multiple data communication networks. This paper will describe the overview of the PLS control system. (author)

382

Intelligent multivariable control system  

OpenAIRE

The objective of this study is to develop an intelligent controller for general nonlinear multivariable systems and implement it in complex grinding processes. Conventional control techniques require a precise analytical model. Fuzzy controllers offer a promising alternative as the system dynamics is captured by human knowledge and experimental data rather than by an accurate analytical model. ^ In this work, a Multi-Level Fuzzy Controller (MLFC) is developed for a general Single-Input Sing...

Xu, Chengying

2006-01-01

383

AUTOMOTIVE DIESEL MAINTENANCE 2. UNIT IX, AUTOMATIC TRANSMISSIONS--HYDRAULIC SYSTEM (PART I).  

Science.gov (United States)

THIS MODULE OF A 25-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF THE OIL FLOW WITHIN HYDRAULIC TRANSMISSIONS USED ON DIESEL POWERED VEHICLES. TOPICS ARE GENERAL DESCRIPTION, HYDRAULIC CIRCUITS, AND BRAKE HYDRAULIC CIRCUIT AND OPERATION. THE MODULE CONSISTS OF A SELF-INSTRUCTIONAL PROGRAMED TRAINING FILM "LEARNING ABOUT THE ALLISON…

Human Engineering Inst., Cleveland, OH.

384

Feasibility study for objective oriented design of system thermal hydraulic analysis program  

International Nuclear Information System (INIS)

The system safety analysis code, such as RELAP5, TRAC, CATHARE etc. have been developed based on Fortran language during the past few decades. Refactoring of conventional codes has been also performed to improve code readability and maintenance. However the programming paradigm in software technology has been changed to use objects oriented programming (OOP), which is based on several techniques, including encapsulation, modularity, polymorphism, and inheritance. In this work, objective oriented program for system safety analysis code has been tried utilizing modernized C language. The analysis, design, implementation and verification steps for OOP system code development are described with some implementation examples. The system code SYSTF based on three-fluid thermal hydraulic solver has been developed by OOP design. The verifications of feasibility are performed with simple fundamental problems and plant models. (author)

385

Applied Control Systems Design  

CERN Document Server

Applied Control System Design examines several methods for building up systems models based on real experimental data from typical industrial processes and incorporating system identification techniques. The text takes a comparative approach to the models derived in this way judging their suitability for use in different systems and under different operational circumstances. A broad spectrum of control methods including various forms of filtering, feedback and feedforward control is applied to the models and the guidelines derived from the closed-loop responses are then composed into a concrete self-tested recipe to serve as a check-list for industrial engineers or control designers. System identification and control design are given equal weight in model derivation and testing to reflect their equality of importance in the proper design and optimization of high-performance control systems. Readers’ assimilation of the material discussed is assisted by the provision of problems and examples. Most of these e...

Mahmoud, Magdi S

2012-01-01

386

Control and optimization system  

Science.gov (United States)

A system for optimizing a power plant includes a chemical loop having an input for receiving an input parameter (270) and an output for outputting an output parameter (280), a control system operably connected to the chemical loop and having a multiple controller part (230) comprising a model-free controller. The control system receives the output parameter (280), optimizes the input parameter (270) based on the received output parameter (280), and outputs an optimized input parameter (270) to the input of the chemical loop to control a process of the chemical loop in an optimized manner.

Xinsheng, Lou

2013-02-12

387

A Fibonacci control system  

OpenAIRE

We study a robot finger model based on a discrete linear control system involving Fibonacci sequence and closely related to the theory of expansions in non-integer bases. The present paper includes an investigation of the reachable workspace, a more general analysis of the control system underlying our model, its reachability and local controllability properties and the relation with expansions in non-integer bases and with iterated function systems.

Lai, Anna Chiara; Loreti, Paola; Vellucci, Pierluigi

2014-01-01

388

Development of a thermal–hydraulic system code, TAPINS, for 10 MW regional energy reactor  

International Nuclear Information System (INIS)

Highlights: ? A thermal–hydraulic system code named TAPINS is developed for simulations of an integral reactor. ? The TAPINS is based on the one-dimensional momentum integral model. ? A dynamic model for the steam–gas pressurizer with non-condensable gas present is proposed. ? A series of pressurizer insurge test and natural circulation test are simulated by the TAPINS. ? It is proved that the TAPINS can provide reliable prediction of an integral reactor system on natural circulation. - Abstract: Small modular reactors (SMRs) with integral system layout have been drawing a great deal of attention as alternative options to branch out the utilization of nuclear energy as well as to offer the inherent safety features. Serving to confirm the design basis and analyze the transient behavior of an integral reactor such as REX-10, a thermal–hydraulic system code named TAPINS (Thermal–hydraulic Analysis Program for INtegral reactor System) is developed in this study. The TAPINS supports the simple pre-processing to build up the frameworks of node diagram for the typical integral reactor configuration. The TAPINS basically consists of mathematical models for the reactor coolant system, the core, the once-through helical-coil steam generator, and the built-in steam–gas pressurizer. The hydrodynamic model of the TAPINS is formulated using the one-dimensional momentum integral model, which is based on the analytical integration of the momentum equation around tntum equation around the closed loop in the system. As a key contribution of the study, a dynamic model for the steam–gas pressurizer with non-condensable gas present is newly proposed and incorporated into the code. The TAPINS is validated by comparing against the experimental data from the pressurizer insurge tests conducted at MIT (Massachusetts Institute of Technology) and natural circulation tests in the RTF (REX-10 Test Facility) at RERI (Regional Energy Reactor Institute). From the comparison results, it is demonstrated that, notwithstanding a few simplifying assumptions and the undemanding solution method to facilitate solutions for transients, the TAPINS can provide a reasonable prediction on the performances and the transients of an integral reactor system operating on natural circulation.

389

Geologic Controls of Hydraulic Conductivity in the Snake River Plain Aquifer At and Near the Idaho National Engineering and Environmental Laboratory, Idaho  

Energy Technology Data Exchange (ETDEWEB)

The effective hydraulic conductivity of basalt and interbedded sediment that compose the Snake River Plain aquifer at and near the Idaho National Engineering and Environmental Laboratory (INEEL) ranges from about 1.0x10 -2 to 3.2x10 4 feet per day (ft/d). This six-order-of-magnitude range of hydraulic conductivity was estimated from single-well aquifer tests in 114 wells, and is attributed mainly to the physical characteristics and distribution of basalt flows and dikes. Hydraulic conductivity is greatest in thin pahoehoe flows and near-vent volcanic deposits. Hydraulic conductivity is least in flows and deposits cut by dikes. Estimates of hydraulic conductivity at and near the INEEL are similar to those measured in similar volcanic settings in Hawaii. The largest variety of rock types and the greatest range of hydraulic conductivity are in volcanic rift zones, which are characterized by numerous aligned volcanic vents and fissures related to underlying dikes. Three broad categories of hydraulic conductivity corresponding to six general types of geologic controls can be inferred from the distribution of wells and vent corridors. Hydraulic conductivity of basalt flows probably is increased by localized fissures and coarse mixtures of interbedded sediment, scoria, and basalt rubble. Hydraulic conductivity of basalt flows is decreased locally by abundant alteration minerals of probable hydrothermal origin. Hydraulic conductivity varies as much as six orders of magnitude in a single vent corridor and varies from three to five orders of magnitude within distances of 500 to 1,000 feet. Abrupt changes in hydraulic conductivity over short distances suggest the presence of preferential pathways and local barriers that may greatly affect the movement of ground water and the dispersion of radioactive and chemical wastes downgradient from points of waste disposal.

S. R. Anderson; M. A. Kuntz; L. C. Davis

1999-02-01

390

KEKB accelerator control system  

International Nuclear Information System (INIS)

The KEKB accelerator control system including a control computer system, a timing distribution system, and a safety control system are described. KEKB accelerators were installed in the same tunnel where the TRISTAN accelerator was. There were some constraints due to the reused equipment. The control system is based on Experimental Physics and Industrial Control System (EPICS). In order to reduce the cost and labor for constructing the KEKB control system, as many CAMAC modules as possible are used again. The guiding principles of the KEKB control computer system are as follows: use EPICS as the controls environment, provide a two-language system for developing application programs, use VMEbus as frontend computers as a consequence of EPICS, use standard buses, such as CAMAC, GPIB, VXIbus, ARCNET, RS-232 as field buses and use ergonomic equipment for operators and scientists. On the software side, interpretive Python and SAD languages are used for coding application programs. The purpose of the radiation safety system is to protect personnel from radiation hazards. It consists of an access control system and a beam interlock system. The access control system protects people from strong radiation inside the accelerator tunnel due to an intense beam, by controlling access to the beamline area. On the other hand, the beam interlock system prevents people from radiation exposure by interlocking the beam operation. For the convenience of accelerator operation and access conce of accelerator operation and access control, the region covered by the safety system is divided into three major access control areas: the KEKB area, the PF-AR area, and the beam-transport (BT) area. The KEKB control system required a new timing system to match a low longitudinal acceptance due to a low-alpha machine. This timing system is based on a frequency divider/multiply technique and a digital delay technique. The RF frequency of the KEKB rings and that of the injector Linac are locked with a common divisor frequency. The common divisor frequency determines the injection timing. The RF bucket selection system is also described

391

Thermal hydraulic characteristics of the pool-type FBR 'ARES' eliminating intermediate heat transfer systems  

International Nuclear Information System (INIS)

An innovative plant concept (ARES), which is eliminating intermediate heat transfer system, was proposed to reduce the construction cost of the liquid metal fast breeder reactor (LMFBR). (1) A thermal-hydraulic transient analysis computer code 'CERES' has been modified to apply various type of LMFBRs, such as 'the tank type', 'the pool type', 'the double-pool type' and 'the tank type eliminating intermediate heat transfer system. The plant transient analysis has been done reveal the thermal hydraulic characteristics of the ARES. The main analytical results are as follows. (2) A proper flow circulation and temperature distribution has been confirmed in the ARES structure under full power operation. It also reveals that the surface velocity is rather fast. Father investigation may be necessary to reduce the suspicion of the wrapping the bubbles. (3) It is confirmed that the core is properly cooled by using rational plant parameters (the flow halving time = 5.5 sec, the flow rate of the pony EMP = 5-7%) under manual trip condition. The temperature stratification occurred in the inner hot plenum. The temperature gradient of the in-vessel structure is acceptable under manual trip condition. (author)

392

Neutron kinetics and thermal-hydraulic transient computational module of the NEPTUNE system: CRONOS  

International Nuclear Information System (INIS)

The NEPTUNE system had been designed to provide all the computational modules needed for a PWR calculation including design fuel management and reactivity accidents; NEPTUNE provides 2D transport assembly calculations and steady state diffusion computations in 1D, 2D, 3D geometries. CRONOS accounts for detailed transient calculations: at each time step the moderator density and the fuel temperature are determined by a refined thermal-hydraulic calculation; these parameters are used as feedback in the neutron-kinetics equations. The treatment of the 3D space dependent kinetics equation is based on the finite element method. This paper is divided into four parts: paragraph 2 presents the finite element treatment of the neutron kinetics equation; paragraph 3 is devoted to the thermal-hydraulic model implemented in Flica 3 and to the numerical treatment; paragraph 4 briefly describes the ARIANE data processing system specially designed for NEPTUNE and in the last part numerical results are presented for a full size rod ejection calculation for a 900 MWe PWR (Fessenheim 2)

393

Thermal-Hydraulic Sensitivity of Intermediate Loop Parameters for Nuclear Hydrogen System  

Energy Technology Data Exchange (ETDEWEB)

To alleviate safety interference between the reactor and hydrogen production systems, certain level of safety distance should be provided by the intermediate loop. Since the intermediate loop performance affects overall nuclear hydrogen system efficiency, it is required to optimize its design and operating parameters. In this study, thermal-hydraulic sensitivity of the intermediate loop parameters with various coolant options has been examined by using MARS-GCR code. Sensitivity of the intermediate loop parameters has been carried out on its thermal-hydraulic performance. Design and operating parameters considered are the diameter and safety distance of concentric loop piping and the operating pressure. Considered coolants are He, CO{sub 2}, N{sub 2}, gas mixtures of He-CO{sub 2} and He-N{sub 2}. It was found that the circulator work is the major factor affecting on the overall nuclear hydrogen production efficiency. Circulator work increases with the safety distance, and decreases with the operating pressure and loop piping diameter. In this result, coolant can be ranked in the order of CO{sub 2}, He, then He-CO{sub 2} mixture and so on for circulator work efficiency. Sensitivity results obtained from this study will contribute to optimization and finalization of the intermediate loop design, operating conditions and the coolant selection.

Lee, Heung N.; Park, Jea Ho; Oh, Jae Yong [Nuclear Team,KONES Co., Seoul (Korea, Republic of); Lee, Won Jae [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2013-10-15

394

The application of Biological-Hydraulic coupled model for Tubificidae-microorganism interaction system  

Science.gov (United States)

Based on the fully coupled activated sludge model (FCASM), the novel model Tubificidae -Fully Coupled Activated Sludge Model-hydraulic (T-FCASM-Hydro), has been developed in our previous work. T-FCASM-Hydro not only describe the interactive system between Tubificidae and functional microorganisms for the sludge reduction and nutrient removal simultaneously, but also considere the interaction between biological and hydraulic field, After calibration and validation of T-FCASM-Hydro at Zhuji Feida-hongyu Wastewater treatment plant (WWTP) in Zhejiang province, T-FCASM-Hydro was applied for determining optimal operating condition in the WWTP. Simulation results showed that nitrogen and phosphorus could be removed efficiently, and the efficiency of NH4+-N removal enhanced with increase of DO concentration. At a certain low level of DO concentration in the aerobic stage, shortcut nitrification-denitrification dominated in the process of denitrification in the novel system. However, overhigh agitation (>6 mg?L-1) could result in the unfavorable feeding behavior of Tubificidae because of the strong flow disturbance, which might lead to low rate of sludge reduction. High sludge reduction rate and high removal rate of nitrogen and phosphorus could be obtained in the new-style oxidation ditch when DO concentration at the aerobic stage with Tubificidae was maintained at 3.6 g?m-3.

Zhong, Xiao; Sun, Peide; Song, Yingqi; Wang, Ruyi; Fang, Zhiguo

2010-11-01

395

Hydraulic belt tension and tracking system for a Van de Graaff accelerator  

International Nuclear Information System (INIS)

In order to eliminate machine openings for simple belt adjustment purposes, a hydraulic belt tension and tracking adjustment system has been developed. Two such independent systems operate one on the upper and one on the lower alternator pillow blocks. The basic belt tension of 4.4 kN (approx. 1000 lb) force is applied to each of the pillow blocks by the hydraulic pistons. Basic fluid pressure of about 7.0 M Pag (approx. 1000 psig) is maintained essentially constant by the relatively large volume of 1000 ml of dry nitrogen in the reservoir. The maximum travel of the piston is about 1.2 cm and the amount of fluid transferred to achieve this is about 80 ml which corresponds to less than 1% change in the reservoir gas volume or pressure, thus maintaining piston force, and hence the belt tension, essentially constant for a belt stretch of as much as 2.5 cm in total circumferential length. As the belt stretches the check valve between the reservoir and piston allows fluid to flow to the piston when the pressure differential exceeds approx. 70 k Pa (10 psi). Reverse fluid flow is blocked however, thus maintaining the mechanical rigidity of the piston in compression, which is essential for stability

396

Thermal-Hydraulic Sensitivity of Intermediate Loop Parameters for Nuclear Hydrogen System  

International Nuclear Information System (INIS)

To alleviate safety interference between the reactor and hydrogen production systems, certain level of safety distance should be provided by the intermediate loop. Since the intermediate loop performance affects overall nuclear hydrogen system efficiency, it is required to optimize its design and operating parameters. In this study, thermal-hydraulic sensitivity of the intermediate loop parameters with various coolant options has been examined by using MARS-GCR code. Sensitivity of the intermediate loop parameters has been carried out on its thermal-hydraulic performance. Design and operating parameters considered are the diameter and safety distance of concentric loop piping and the operating pressure. Considered coolants are He, CO2, N2, gas mixtures of He-CO2 and He-N2. It was found that the circulator work is the major factor affecting on the overall nuclear hydrogen production efficiency. Circulator work increases with the safety distance, and decreases with the operating pressure and loop piping diameter. In this result, coolant can be ranked in the order of CO2, He, then He-CO2 mixture and so on for circulator work efficiency. Sensitivity results obtained from this study will contribute to optimization and finalization of the intermediate loop design, operating conditions and the coolant selection

397

[Effects of controlled alternate partial root-zone drip irrigation on apple seedling morphological characteristics and root hydraulic conductivity].  

Science.gov (United States)

To investigate the effects of alternate partial root-zone drip irrigation (ADI) on the morphological characteristics and root hydraulic conductivity of apple seedlings, three irrigation modes, i.e., fixed partial root-zone drip irrigation (FDI, fixed watering on one side of the seedling root zone), controlled alternate partial root-zone drip irrigation (ADI, alternate watering on both sides of the seedling root zone), and conventional drip irrigation (CDI, watering cling to the seedling base), and three irrigation quotas, i. e., each irrigation amount of FDI and ADI was 10, 20 and 30 mm, and that of CDI was 20, 30 and 40 mm, respectively, were designed. In treatment ADI, the soil moisture content on the both sides of the root zone appeared a repeated alternation of dry and wet process; while in treatment CDI, the soil moisture content had less difference. At the same irrigation quotas, the soil moisture content at the watering sides had no significant difference under the three drip irrigation modes. At irrigation quota 30 mm, the root-shoot ratio, healthy index of seedlings, and root hydraulic conductivity in treatment ADI increased by 31.6% and 47.1%, 34.2% and 53.6%, and 9.0% and 11.0%, respectively, as compared with those in treatments CDI and FDI. The root dry mass and leaf area had a positive linear correlation with root hydraulic conductivity. It was suggested that controlled alternate partial root-zone drip irrigation had obvious compensatory effects on the root hydraulic conductivity of apple seedlings, improved the soil water use by the roots, benefited the equilibrated dry matter allocation in seedling organs, and markedly enhanced the root-shoot ratio and healthy index of the seedlings. PMID:22919832

Yang, Qi-Liang; Zhang, Fu-Cang; Liu, Xiao-Gang; Ge, Zhen-Yang

2012-05-01

398

Preliminary thermal-hydraulic and safety analysis of China DFLL-TBM system  

International Nuclear Information System (INIS)

Highlights: • Thermal-hydraulic and safety analysis on DFLL-TBM system is performed. • The TBM FW maximum temperature is 541 °C under steady state condition. • The TBM FW maximum temperature does not exceed the melt point of CLAM steel 1500 °C. • Neither the VV pressurization nor vault pressure build-up goes beyond 0.2 MPa. -- Abstract: China has proposed the dual-functional lithium-lead (DFLL) tritium breeding blanket concept for testing in ITER as a test blanket module (TBM), to demonstrate the technologies of tritium self-sufficiency, high-grade heat extraction and efficient electricity production which are needed for DEMO and fusion power plant. Safety assessment of the TBM and its auxiliary system should be conducted to deal with ITER safety issues directly caused by the TBM system failure during the design process. In this work, three potential initial events (PIEs) – in-vessel loss of helium (He) coolant and ex-vessel loss of He coolant and loss of flow without scram (LOFWS) – were analyzed for the TBM system with a modified version of the RELAP5/MOD3 code containing liquid lithium-lead eutectic (LiPb). The code also comprised an empirical expression for MHD pressure drop relevant to three-dimensional (3D) effect, the Lubarsky–Kaufman convective heat transfer correlation for LiPb flow and the Gnielinski convective heat transfer correlation for He flow. Since both LiPb and He serve as TBM coolants, the LiPb and He ancillary cooling systems were modeled to investigate the thermal-hydraulic characteristic of the TBM system and its influence on ITER safety under those accident conditions. The TBM components and the coolants flow within the TBM were simulated with one-dimensional heat structures and their associated hydrodynamic components. ITER enclosures including vacuum vessel (VV), port cell and TCWS vault were also covered in the model for accident analyses. Through this best estimate approach, the calculation indicated that the current design of DFLL-TBM and its auxiliary system meets the thermal-hydraulic and safety requirements from ITER

399

Preliminary thermal-hydraulic and safety analysis of China DFLL-TBM system  

Energy Technology Data Exchange (ETDEWEB)

Highlights: • Thermal-hydraulic and safety analysis on DFLL-TBM system is performed. • The TBM FW maximum temperature is 541 °C under steady state condition. • The TBM FW maximum temperature does not exceed the melt point of CLAM steel 1500 °C. • Neither the VV pressurization nor vault pressure build-up goes beyond 0.2 MPa. -- Abstract: China has proposed the dual-functional lithium-lead (DFLL) tritium breeding blanket concept for testing in ITER as a test blanket module (TBM), to demonstrate the technologies of tritium self-sufficiency, high-grade heat extraction and efficient electricity production which are needed for DEMO and fusion power plant. Safety assessment of the TBM and its auxiliary system should be conducted to deal with ITER safety issues directly caused by the TBM system failure during the design process. In this work, three potential initial events (PIEs) – in-vessel loss of helium (He) coolant and ex-vessel loss of He coolant and loss of flow without scram (LOFWS) – were analyzed for the TBM system with a modified version of the RELAP5/MOD3 code containing liquid lithium-lead eutectic (LiPb). The code also comprised an empirical expression for MHD pressure drop relevant to three-dimensional (3D) effect, the Lubarsky–Kaufman convective heat transfer correlation for LiPb flow and the Gnielinski convective heat transfer correlation for He flow. Since both LiPb and He serve as TBM coolants, the LiPb and He ancillary cooling systems were modeled to investigate the thermal-hydraulic characteristic of the TBM system and its influence on ITER safety under those accident conditions. The TBM components and the coolants flow within the TBM were simulated with one-dimensional heat structures and their associated hydrodynamic components. ITER enclosures including vacuum vessel (VV), port cell and TCWS vault were also covered in the model for accident analyses. Through this best estimate approach, the calculation indicated that the current design of DFLL-TBM and its auxiliary system meets the thermal-hydraulic and safety requirements from ITER.

Li, Wei [School of Nuclear Science and Technology, Xi’an Jiaotong University, No. 28, Xianning West Road, Xi’an, Shanxi 710049 (China); Tian, Wenxi, E-mail: wxtian@mail.xjtu.edu.cn [School of Nuclear Science and Technology, Xi’an Jiaotong University, No. 28, Xianning West Road, Xi’an, Shanxi 710049 (China); Qiu, Suizheng; Su, Guanghui; Jiao, Hong [School of Nuclear Science and Technology, Xi’an Jiaotong University, No. 28, Xianning West Road, Xi’an, Shanxi 710049 (China); Bai, Yunqing; Chen, Hongli [Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Wu, Yican, E-mail: yican.Wu@Fds.Org.Cn [Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, Hefei, Anhui 230031 (China)

2013-06-15

400

Hydraulic classifier system for fractionation of nano CaCO3 particles  

Science.gov (United States)

A laboratory scale hydraulic classifier system was developed for calcium carbonate nanoparticles fractionation. The system is based on the differences in the settling velocity of particles in aqueous fluid at different dynamic viscosities along different settling stages. Different factors affecting the fractionation process were studied, such as the effect of water volume, L, terminal (settling) velocity in different stages, ?s, CaCO3 feed concentration, g/L and flow rate (L/h) of the dispersed fluid solution. The particles obtained were characterized using SEM and showed that the developed system can fractionate particles within the size range 25-33 nm. A simple model for the results obtained is developed and discussed in terms of the different parameters affecting particles size is given. Further, the calcium carbonate used was characterized before and after fractionations using Vibratory sieve shaker, SEM, EDS, XRD and FTIR.

Aly, H. F.; Akl, M. A.; Soliman, Hesham M. A.; AbdEl-Rahman, Aref M. E.; Abd-Elhamid, A. I.

2014-07-01

401

Design of in-situ reactive wall systems - a combined hydraulical-geochemical-economical simulation study  

International Nuclear Information System (INIS)

The paper presents a coupled hydraulical-geochemical-economical simulation model for the design of in-situ reactive wall systems. More specific, the model is used for cost-optimization and sensitivity analysis of a funnel-and-gate system with an in-situ sorption reactor. The groundwater flow and advective transport are simulated under steady-state conditions using a finite-difference numerical model. This model is coupled to an analytical solution describing the sorption kinetics of hydrophobic organic compounds within the reactor (gate). The third part of the model system is an economical model which calculates (a) the investment costs for the funnel-and-gate construction and (b) the operation cost based on the number of reactor refills, which depends on the breakthrough time for a given contaminant and the anticipated total operation time. For practical applications a simplified approximation of the cost-function is derived and tested

402

Discrete control systems  

CERN Document Server

Discrete Control Systems establishes a basis for the analysis and design of discretized/quantized control systemsfor continuous physical systems. Beginning with the necessary mathematical foundations and system-model descriptions, the text moves on to derive a robust stability condition. To keep a practical perspective on the uncertain physical systems considered, most of the methods treated are carried out in the frequency domain. As part of the design procedure, modified Nyquist–Hall and Nichols diagrams are presented and discretized proportional–integral–derivative control schemes are reconsidered. Schemes for model-reference feedback and discrete-type observers are proposed. Although single-loop feedback systems form the core of the text, some consideration is given to multiple loops and nonlinearities. The robust control performance and stability of interval systems (with multiple uncertainties) are outlined. Finally, the monograph describes the relationship between feedback-control and discrete ev...

Okuyama, Yoshifumi

2014-01-01

403

Rock specific hydraulic fracturing and matrix acidizing to enhance a geothermal system — Concepts and field results  

Science.gov (United States)

Enhanced geothermal systems (EGS) are engineered reservoirs developed to extract economic amounts of heat from low permeability and/or porosity geothermal resources. To enhance the productivity of reservoirs, a site specific concept is necessary to actively make reservoir conditions profitable using specially adjusted stimulation treatments, such as multi fracture concepts and site specific well path design. The results of previously performed stimulation treatments in the geothermal research well GtGrSk4/05 at Groß Schönebeck, Germany are presented. The reservoir is located at a 4100-4300 m depth within the Lower Permian of the NE German Basin with a bottom-hole temperature of 150 °C. The reservoir rock is classified by two lithological units from bottom to top: volcanic rocks (andesitic rocks) and siliciclastics ranging from conglomerates to fine-grained sandstones (fluvial sediments). The stimulation treatments included multiple hydraulic stimulations and an acid treatment. In order to initiate a cross-flow from the sandstone layer, the hydraulic stimulations were performed in different depth sections (two in the sandstone section and one in the underlying volcanic section). In low permeability volcanic rocks, a cyclic hydraulic fracturing treatment was performed over 6 days in conjunction with adding quartz in low concentrations to maintain a sustainable fracture performance. Flow rates of up to 150 l/s were realized, and a total of 13,170 m 3 of water was injected. A hydraulic connection to the sandstone layer was successfully achieved in this way. However, monitoring of the water level in the offsetting well EGrSk3/90, which is 475 m apart at the final depth, showed a very rapid water level increase due to the stimulation treatment. This can be explained by a connected fault zone within the volcanic rocks. Two gel-proppant treatments were performed in the slightly higher permeability sandstones to obtain long-term access to the reservoir rocks. During each treatment, a total of 100 ton of high strength proppants was injected with 500 m 3 of cross-linked gel. The subsequent production test in conjunction with flowmeter logging showed an improvement of productivity by a factor of more than 4. Due to assumed residual drilling mud (constituents: calcite, dolomite, and aragonite) in the near-wellbore vicinity, an acid matrix stimulation was performed thereafter using a coil tubing unit. The following nitrogen lift test demonstrated another increase of productivity by 30-50% to an overall increase by a factor of 5.5-6.2.

Zimmermann, Günter; Blöcher, Guido; Reinicke, Andreas; Brandt, Wulf

2011-04-01

404

Neutron generator control system  

International Nuclear Information System (INIS)

A method is described of controlling the neutron output of a neutron generator tube used in neutron well logging. The system operates by monitoring the target beam current and comparing a function of this current with a reference voltage level to develop a control signal used in a series regulator to control the replenisher current of the neutron generator tube. (U.K.)

405

Kinetic ceramics piezoelectric hydraulic pumps  

Science.gov (United States)

This paper discusses the development and testing of two Piezoelectrically driven Hydraulic Pumps (PHP2 & PHP3) utilizing low cost discrete multilayer piezoelectric actuators and low cost structural components. New valve technologies were developed utilizing reed and MEMS valves. Structural optimization was performed to decrease weight and volume. The PHP3 design extracts power from a PZT material with high efficiency despite impedance mismatch between the piezoelectric actuator and fluid by utilizing a hydraulic pendulum energy recovery technique. Hydraulic power of 168 watts can be developed with a pump mass of under 1lb. Flow rate of 2300 cc/min free flow has been demonstrated as well as output pressure greater than 200 bar in the stalled condition. The result of the effort is practical solid state conversion of electrical energy into a useable hydraulic source for actuation systems without having normal rotational wear components. The PHP2 pump was used to power the hydraulic primary flight controls in a RPV technology demonstrator flight tested in November 2006.

O'Neill, Conal; Burchfield, John

2007-04-01

406

Control system design guide  

Energy Technology Data Exchange (ETDEWEB)

The ''Control System Design Guide'' (Design Guide) provides methods and recommendations for the control system design process and control point selection and installation. Control systems are often the most problematic system in a building. A good design process that takes into account maintenance, operation, and commissioning can lead to a smoothly operating and efficient building. To this end, the Design Guide provides a toolbox of templates for improving control system design and specification. HVAC designers are the primary audience for the Design Guide. The control design process it presents will help produce well-designed control systems that achieve efficient and robust operation. The spreadsheet examples for control valve schedules, damper schedules, and points lists can streamline the use of the control system design concepts set forth in the Design Guide by providing convenient starting points from which designers can build. Although each reader brings their own unique questions to the text, the Design Guide contains information that designers, commissioning providers, operators, and owners will find useful.

Sellers, David; Friedman, Hannah; Haasl, Tudi; Bourassa, Norman; Piette, Mary Ann

2003-05-01

407

Proceedings of the fifth nuclear thermal hydraulics  

International Nuclear Information System (INIS)

This book contains the fifth proceedings of Nuclear Thermal Hydraulics. Topics covered include: General Thermal-Hydraulics Modeling and Experiments; Thermal-Hydraulics Aspects of Passive Safety and New Generation Reactors; Thermal Hydraulics of Severe Accidents and Degraded Cores; General Thermal-Hydraulics Modeling and Experiments; Scaling and Uncertainties in Computer Code Predictions; Thermal Hydraulics of Reactor Operations; Thermal-Hydraulic Aspects of Passive Safety and New Generation Reactors; Thermal-Hydraulic Reactor Systems; and Thermal-Hydraulic Aspects of Passive Safety and New Generation Reactors

408

Auto-control algorithm for the phase interface height based on the hydraulic character of pulsed column  

International Nuclear Information System (INIS)

The paper carried out studies on the auto-control algorithm of the phase interface height based on the hydraulic character of pulsed column. Emphasis was put on the stability of auto-control process and the parameters of the algorithm can be easily determined. According to the results of hydraulic character studies, resonance of the holdup and the phase interface height may be aroused if usual industrial control algorithm is applied without considering their mutual influences. The paper puts forward a combined and revised PID algorithm with much emphasis on the stability of the control process. The algorithm consists of standard PI method for fine adjustment when the measurement value is close to the setting value, and the revised pure proportion method for rough adjustment when the measurement value is deviated greatly from the setting value. The parameters are easily obtained by calculating the inlet and outlet flow rates, the structural sizes, and the measurement errors. Simulation experiments and real cold uranium mass transfer experiments were conducted based on the algorithm. In the real control experiments, once-through steady state was reached without overshoot in 10 minutes and relative change rate of the outlet flow was less than ±10%. (author)

409

MOBILE ROBOT CONTROL SYSTEM  

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents a simple concept of low cost mobile robot control system for source following applications. The robot uses two analog sensors and two independent motors for steering. The control system itself is a modified class D amplifier that generates complementary PWM signals modulated by the difference of the signals from the sensors.

Marius Sebastian Rusu

2012-11-01

410

Biogas plant control system  

International Nuclear Information System (INIS)

This paper presents intelligent control system for the pig farm biogas production process. The system uses a fuzzy logic models based on knowledge of experts and operators. Four fuzzy models are introduced. The adequacy of fuzzy models is verified using real data and MATLAB simulation. Proposed expert system is implemented into traditional SCADA system for biogas process prediction and failure analyzing. (authors)