WorldWideScience
1

Control rod drive hydraulic system  

Science.gov (United States)

A hydraulic system for a control rod drive (CRD) includes a variable output-pressure CR pump operable in a charging mode for providing pressurized fluid at a charging pressure, and in a normal mode for providing the pressurized fluid at a purge pressure, less than the charging pressure. Charging and purge lines are disposed in parallel flow between the CRD pump and the CRD. A hydraulic control unit is disposed in flow communication in the charging line and includes a scram accumulator. An isolation valve is provided in the charging line between the CRD pump and the scram accumulator. A controller is operatively connected to the CRD pump and the isolation valve and is effective for opening the isolation valve and operating the CRD pump in a charging mode for charging the scram accumulator, and closing the isolation valve and operating the CRD pump in a normal mode for providing to the CRD through the purge line the pressurized fluid at a purge pressure lower than the charging pressure.

Ose, Richard A. (San Jose, CA)

1992-01-01

2

Control rod drive hydraulic system  

International Nuclear Information System (INIS)

This patent describes a hydraulic system for a control rod drive (CRD). It comprises a variable output-pressure CRD pump; a charging line disposed in flow communication between the CRD pump and the CRD; a purge line disposed in flow communication between the CRD pump and the CRD, and in parallel flow with the charging line; a hydraulic control unit (HCU) disposed in flow communication in the charging line between the isolation valve and the CRD and including in series flow in the charging line an HCU check valve and a normally closed scram valve, and a scram accumulator disposed therebetween for accumulating the scram fluid at the charging pressure during the charging mode; pressurizing means disposed in flow communication with the charging line downstream of the isolation valve and upstream of the scram valve; a pressure sensor operatively connected to the charging line and responsive to the scram pressure; control means operatively connected to the CRD pump, the isolation valve, and the pressure sensor, and being effective for: opening the isolation valve while the scram valve is closed when the scram pressure drops to the minimum scram pressure; and closing the isolation valve while the scram valve is closed when the scram fluid in the charging line and in the scram accumulator reaches the charging pressure

3

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

4

Hydraulic Actuator System for Rotor Control  

Science.gov (United States)

In the last ten years, several different types of actuators were developed and fabricated for active control of rotors. A special hydraulic actuator system capable of generating high forces to rotating shafts via conventional bearings is addressed. The actively controlled hydraulic force actuator features an electrohydraulic servo valve which can produce amplitudes and forces at high frequencies necessary for influencing rotor vibrations. The mathematical description will be given in detail. The experimental results verify the theoretical model. Simulations already indicate the usefulness of this compact device for application to a real rotor system.

Ulbrich, Heinz; Althaus, Josef

1991-01-01

5

TG 220 MW hydraulic control system diagnostics  

International Nuclear Information System (INIS)

The TG power output control system comprises a hydraulic and an electronic part. TG speed, power output or the main steam header pressure (HPK) depend on the steam flow at the turbine inlet. The steam admission into the turbine is controlled by four control valves and one by-pass valve in case of the HP part and by four capture flap valves in case of the LP part. The task of the SKODA K-220 MW turbine protection and control systems is to provide both the turbine speed and power output control to the setpoint value. Diagnostic measurements were aimed at getting an overview of both technical and functional states of all power output control elements. Principally, it can be stated that some deficiencies of a design nature originating from the manufacturer's factory were revealed and some other deficiencies related to hydraulic control elements functionality were identified more closely by the new method. 5 figs

6

Control Reconfigurability of Bilinear Hydraulic Drive Systems  

DEFF Research Database (Denmark)

The objective of the methods within the framework of the plug and play process control and particularly fault tolerant control is to establish control techniques which guarantee a certain performance through control reconfiguration at the occurrence of the faults or changes. These methods cannot be effective if sufficient redundancy does not exist in the process. A measure for control reconfigurability which reveals the level of redundancy in connection with feedback control is proposed in this paper for bilinear systems. The proposed control reconfigurability measure is the extension of its gramian-based analogous counterpart, which has been previously proposed for the linear processes. The control reconfigurability is calculated for the bilinear models of an electro-hydraulic drive to show its relevance to redundant actuating capabilities in the models.

Shaker, Hamid Reza; Tahavori, Maryamsadat

2011-01-01

7

Robust control of hydraulically operated gimbal system  

International Nuclear Information System (INIS)

A transmitting antenna operated on the naval vessels can be easily excited by exogenous disturbances such as tidal wave and impact. Gimbal system that supports the antenna needs the controller to maintain the robust performance against various modeling uncertainties and disturbance. PI controller, however, cannot guarantee the reasonable robust performance under these kinds of severe conditions. Thus a robust H ? control scheme is recommended to ensure a specified dynamic response under heavy operating conditions. Gimbal system is simplified as two degree of freedom model that ignores coordinate co-relations of each direction and hydraulic system is modelled linearly. The simulation and experimental results of H ? controller proposed in this paper showed the better responses and stability than those of PI controller

8

Robust control of hydraulically operated gimbal system  

Energy Technology Data Exchange (ETDEWEB)

A transmitting antenna operated on the naval vessels can be easily excited by exogenous disturbances such as tidal wave and impact. Gimbal system that supports the antenna needs the controller to maintain the robust performance against various modeling uncertainties and disturbance. PI controller, however, cannot guarantee the reasonable robust performance under these kinds of severe conditions. Thus a robust H {infinity} control scheme is recommended to ensure a specified dynamic response under heavy operating conditions. Gimbal system is simplified as two degree of freedom model that ignores coordinate co-relations of each direction and hydraulic system is modelled linearly. The simulation and experimental results of H {infinity} controller proposed in this paper showed the better responses and stability than those of PI controller.

Cho, Taik Dong; Yang, Sang Min [Chungnam National University, Daejeon (Korea, Republic of)

2007-05-15

9

Pressure control of hydraulic servo system using proportional control valve  

International Nuclear Information System (INIS)

The purpose of this study is to develop a control scheme for the hydraulic servo system which can rapidly control the pressure in a hydraulic cylinder with very short stroke. Compared with the negligible stroke of the cylinder in the system, the flow gain of the proportional pressure control valve constituting the hydraulic servo system is relatively large and the time delay on the response of the valve is quite long. Therefore, the pressure control system, in this study tends to get unstable during operations. Considering the above mentioned characteristics of the system, a two-degree-of-freedom control scheme, composed of the I-PDD2... feedback compensator and the feedforward controller, is proposed. The reference model scheme is used in deciding the parameters of the controllers. The validity of the proposed control scheme is confirmed through the experiments

10

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.)

11

Fuzzy control of hydraulic servo system based on DSP  

Science.gov (United States)

On the basis of high-speed switching valve of hydraulic servo system, the complex mathematical model of nonlinear hydraulic servo system was analyzed and constructed. A intelligent Fuzzy control method using TMS320LF2407A DSP chip as primary processor was put forward. The simulation results show that the control strategy has a better effect than the conventional PID control has. And the non-differential control of the system has been basically achieved.

He, Juan; Yuan, Song-Yue

2011-10-01

12

A Flexible Adjustment and Control System for Hydraulic Machines  

OpenAIRE

Due to the advantages of hydraulic systems with variable displacement, it was necessary to design a control system that can adjust the pressure, flow, power or a combination of these features, that can be easily integrated into the pump body without changing its mechanical construction. The objective of this work was to study the dynamic behavior of this electro-hydraulic control system. To achieve these objectives, first the adjusting system was analyzed by numerical simulations, and then a ...

Daniel Banyai; Lucian Marcu

2012-01-01

13

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

14

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 PID controller and derive control law. Using fuzzy strategy approximating antibodies...

Ma Yu; Gu Lichen

2013-01-01

15

Modeling and Control for an Asymmetric Hydraulic Active Suspension System  

Science.gov (United States)

In this paper we present a model for an automotive active suspension system which includes the dynamics of an asymmetric hydraulic actuator. In this model the force exerted by a single-rod cylinder is regarded as an internal state, and the sum of the oil flow rates through the orifice of a servo valve as the control input. We obtain a linear time-invariant (LTI) state state equation and propose a force-tracking-free one-step control method which can accept various linear control techniques. An optimal state-feedback control is applied as an example. Quarter car test rig experiment results show the effectiveness of the proposed approach in modeling and control.

Kim, Wanil; Won, Sangchul

16

Fuzzy Immune PID Control of Hydraulic System Based on PSO Algorithm  

Directory of Open Access Journals (Sweden)

Full Text Available 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 PID controller and derive control law. Using fuzzy strategy approximating antibodies inhibit adjustment function to enhance the stability and robustness of the system, and designing fuzzy immune PID controller, parameters of controller are self-optimized by particle swarm (PSO algorithm. This controller is applied to a hydraulic system, and achieved the precise control of the system flow in a variety of typical conditions. Simulation results show that: the controller can immune modulate automatically according to the dynamic changes of load of the hydraulic system, with fast tracking, small overshoot, and strong robustness advantages.

Ma Yu

2013-02-01

17

Maintaining hydraulic control using deep rooted tree systems.  

Science.gov (United States)

Groundwater phytotechnology systems are currently being used to control the migration of contaminant plumes and remove groundwater that flows into containment areas. Trees in such systems function by reducing recharge and using groundwater via transpiration. A stand of deep-rooted trees can act as a biological "pump", removing a substantial amount of water from the saturated zone. Depth to groundwater compared to rooting depth is an important consideration. Many useful tree species are not naturally deep-rooted, but various cultural practices can produce trees with roots that are deep enough to tap into the water table. Hydraulic control can be calculated or modeled using equations that compare transpired water to groundwater flow and take into account site-specific geologic and climatic variables. However, field measurements should be carried out whenever possible to obtain more precise estimates of groundwater capture and control. PMID:12674401

Ferro, A; Gefell, M; Kjelgren, R; Lipson, D S; Zollinger, N; Jackson, S

2003-01-01

18

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

19

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)

20

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

21

Virtual Design of a Controller for a Hydraulic Cam Phasing System  

Science.gov (United States)

Hydraulic vane cam phasing systems are nowadays widely used for improving the performance of combustion engines. At stationary operation, these systems should achieve a constant phasing angle, which however is badly disturbed by the alternating torque generated by the valve actuation. As the hydraulic system shows a non-linear characteristic over the full operation range and the inductivity of the hydraulic pipes generates a significant time delay, a full model based control emerges very complex. Therefore a simple feed-forward controller is designed, bridging the time delay of the hydraulic system and improving the system behaviour significantly.

Schneider, Markus; Ulbrich, Heinz

2010-09-01

22

System and method for controlling hydraulic pressure in electro-hydraulic valve actuation systems  

Science.gov (United States)

A control system for an engine includes a first lift control module and a second lift control module. The first lift control module increases lift of M valves of the engine to a predetermined valve lift during a period before disabling or re-enabling N valves of the engine. The second lift control module decreases the lift of the M valves to a desired valve lift during a period after enabling or re-enabling the N valves of the engine, wherein N and M are integers greater than or equal to one.

Brennan, Daniel G; Marriott, Craig D; Cowgill, Joel; Wiles, Matthew A; Patton, Kenneth James

2014-09-23

23

Evaluation of Linear and Non-Linear Control Schemes Applied to a Hydraulic Servo System  

DEFF Research Database (Denmark)

Due to the innovation of low-cost electronics such as sensors, microcontrollers etc., the focus on highperformance motion control is increasing. This work focuses on position control of single-input single-output hydraulic servo-systems in general. A hydraulically actuated robotic manipulator is used as test facility acting as load for the hydraulic servo system. An experimentally verified non-linear model of the complete system has been developed and used to design a series of both linear and non-linear control schemes. The controllers from each category are compared with respect to design parameters such as performance, robustness and implementation

Andersen, Torben Ole; Hansen, Michael Rygaard

2005-01-01

24

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

25

Specific features pertinent to modeling of hydraulic systems containing control members  

Science.gov (United States)

The theoretical principles applied for modeling of hydraulic systems fitted with control members that allow a hydraulic line's specific features (topology) to be taken into account are considered. Such modeling opens the possibility to predict the actual flow (throttling) characteristics at early design stages and timely introduce the appropriate corrections in pipeline topology. The modeling problem is solved with the use of generalized thermodynamic analysis methods. The mathematical models of hydraulic systems containing control members are brought to the level of real-time simulation models, which can be used for setting up computation experiments for achieving better performance of automatic closed-loop control systems.

Tverskoy, Yu. S.; Marshalov, E. D.

2014-09-01

26

Study on Control Strategy of Electro-Hydraulic Servo Loading System  

OpenAIRE

Since extraneous torque is the key factor to affect the accuracy of electro-hydraulic servo loading system, the forming mechanism of extraneous torque was discussed in this work. And then several design methods of loading system controller based on modern control theory were introduced, such as internal model control, Cerebella model articulation control and adaptive backstepping control.

Ju Tian

2013-01-01

27

Error evaluation of the linearized equation of servo valve in hydraulic control systems  

International Nuclear Information System (INIS)

In the procedure of the hydraulic control system analysis, a linearized approximate equation described by the first order term of Taylor's series has been widely used. Such a linearized equation is effective just near the operating point. In this study, the authors estimate computational errors in the process of applying the existing linearized equation stated above. For evaluating the computational accuracy in practical applications of the linearized equations, dynamic behaviors of hydraulic control systems are investigated through simulations with several kinds of representative hydraulic systems and the linearized equations suggested in this study

28

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.

29

RETRAN: a computer code for analyzing the dynamics and control of thermal-hydraulic systems  

International Nuclear Information System (INIS)

The paper describes the RETRAN thermal-hydraulics transient analysis computer code system and addresses its application toward the solution of process control design and evaluation problems. The basic structure of the code provides the capability to analyze a wide spectrum of problems. This capability ranges from the detailed thermal-hydraulic calculations required to analyze a nuclear power plant loss-of-coolant accident (LOCA) to the analysis of a single instrument response characteristic. The instrumentation response solutions are directly coupled to the thermal hydraulic solutions, thus accounting for feedback responses in the analyses. The advantages of the code lie in the fact that it is a totally digital computer code system, and that any degree of sophistication of either the thermal-hydraulics solution or the control and instrumentation control solution can be modeled through user input

30

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

31

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

32

Pressure control in hydraulic systems with variable or constant pumps?  

OpenAIRE

The paper deals with electrohydraulic supply systems with variable (adjustable( supply pressures. Two control concepts are used in practice: the pressure control concept using a variable pump and constant speed of the driving electric motor as the commonly used concept, and the pressure control concept with a constant pump and a speed-controlled electric motor as the alternative concept. The typical features and the applicability of both conceps, as well as their dynamic responses are studied...

Lovrec, Darko; Ulaga, Samo

2012-01-01

33

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

34

Design and Optimization of Controllers for an Electro-Hydraulic System  

OpenAIRE

Electro-Hydraulic (EH) systems are commonly used in the industry for applications that require high power-weight ratios and large driving forces. The EH system studied in this master thesis have recently been upgraded with new hardware components and as a part of this upgrade a new controller was requested. The system consists of a controller that computes a control signal for an electric motor. The motor drives a gear pump that generates a flow of hydraulic fluid. The flow is then directed t...

Andre?, Simon

2014-01-01

35

Control method and system for hydraulic machines employing a dynamic joint motion model  

Science.gov (United States)

A control method and system for controlling a hydraulically actuated mechanical arm to perform a task, the mechanical arm optionally being a hydraulically actuated excavator arm. The method can include determining a dynamic model of the motion of the hydraulic arm for each hydraulic arm link by relating the input signal vector for each respective link to the output signal vector for the same link. Also the method can include determining an error signal for each link as the weighted sum of the differences between a measured position and a reference position and between the time derivatives of the measured position and the time derivatives of the reference position for each respective link. The weights used in the determination of the error signal can be determined from the constant coefficients of the dynamic model. The error signal can be applied in a closed negative feedback control loop to diminish or eliminate the error signal for each respective link.

Danko, George (Reno, NV)

2011-11-22

36

System and method for controlling engine knock using electro-hydraulic valve actuation  

Science.gov (United States)

A control system for an engine includes a knock control module and a valve control module. The knock control module adjusts a period that one or more of an intake valve and an exhaust valve of a cylinder are open based on engine knock corresponding to the cylinder. The valve control module, based on the adjusted period, controls the one or more of the intake valve and the exhaust valve using one or more hydraulic actuators.

Brennan, Daniel G

2013-12-10

37

Redundant hydraulic secondary flight control systems behavior in failure conditions  

OpenAIRE

The flight control systems, designed in order to assure the necessary safety level even in failure conditions, are generally characterized by a proper redundant layout. The redundancies must be designed in order to assure an adequate system behavior when some failures are present; in fact an incorrect layout may cause serious shortcomings concerning the response when some component is not operational. Therefore the usual correct design activities request the complete analysis of the system be...

Borello, Lorenzo; Villero, Giuseppe; Dalla Vedova, Matteo Davide Lorenzo

2013-01-01

38

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

OpenAIRE

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 ...

Choux, M.; Hovland, G.

2010-01-01

39

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.)

40

Using Feedback Error Learning for Control of Electro Hydraulic Servo System by Laguerre  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper, a new Laguerre controller is proposed to control the electro hydraulic servo system. The proposed controller uses feedback error learning method and leads to significantly improve performance in terms of settling time and amplitude of control signal rather than other controllers. All derived results are validated by simulation of nonlinear mathematical model of the system. The simulation results show the advantages of the proposed method for improved control in terms of both settling time and amplitude of control signal.

Amir Reza Zare Bidaki

2014-01-01

41

Design and development of low speed dynamometer using electro hydraulic servo control system  

International Nuclear Information System (INIS)

High torque low speed oil hydraulic motors are required to be used in fuelling machine of 500 MWe PHWRs. High torque low speed motors presently available in market are designed for heavy earth moving equipment where high torque at moderately low speed is desired. To test these types of motors, low speed dynamometers are required. An attempt has been made to develop an indigenous low speed dynamometer by electro hydraulic servo control system which can overcome the drawbacks of powder type dynamometer design. (author). 5 refs., 4 figs

42

Hydraulic reactivity control method  

International Nuclear Information System (INIS)

An extension tube is disposed to each of control rod guide tubes in which a control rod is loaded as it is, an opening/closing valve is disposed to the upper end, and a closed space in common to the entire and a portion of the extension tube is disposed to the upper portion of the valve. Coolants in the closed space is sucked by a pump to cause differential pressure sufficient to float the control rod hydraulically between the lower end of the control rod guide tube and the valve at the upper end of the extension tube by the hydraulic force when the valve is opened. When the opening/closing valve at the upper end of a predetermined extension tube is opened, the control rod in the control rod guide tube connected to the extension tube is elevated hydraulically by the flow between the upper and lower end to insert it to the extension tube thereby making the reactor core to an entirely drawn state. In addition, when the opening/closing valve is closed, the control rod in a predetermined extension tube is lowered by gravitational force by the reduction of the flow rate between the upper and the lower end to make the reactor core to an entire insertion state. Then, an axial neutron flux distribution is not caused, and the design and manufacture of the inner structural members in the reactor core can be facilitated. (N.H.)

43

Space Shuttle Main Engine control system. [hydraulic actuator with digital control  

Science.gov (United States)

The Space Shuttle Main Engine is a reusable, high-performance rocket engine being developed by the Rocketdyne Div. of Rockwell International to satisfy the operational requirements of the Space Shuttle Orbiter Vehicle. The design incorporates a hydraulically actuated, closed-loop servosystem controlled and monitored by a programmable electronic digital controller. The controller accepts vehicle commands for the various engine operational phases, positions the appropriate valves, monitors the engine for the required performance precisions and conditions, and provides redundancy management.

Seitz, P. F.; Searle, R. F.

1973-01-01

44

A new linearized equation for servo valve in hydraulic control systems  

International Nuclear Information System (INIS)

In the procedure of the hydraulic control system analysis, a linearized approximate equation described by the first order term of Taylor's series has been widely used. Such a linearized equation is effective just near the operating point. And, as of now, there are no general standards on how to determine the operating point of a servo valve in the process of applying the linearized equation. So, in this study, a new linearized equation for valve characteristics is proposed as a modified form of the existing linearized equation. And, a method for selecting an optimal operating point is proposed for the new linearized equation. The effectiveness of the new linearized equation is confirmed through numerical simulations and experiments for a model hydraulic control system

45

High Precision Position Control of Electro-Hydraulic Servo System Based on Feed-Forward Compensation  

OpenAIRE

The study is focused on an electro-hydraulic servo system which is a position control system. It is a non-minimum phase system when it was discretized with a certain sample time. To improve its tracking performance and extend its bandwidth, based on invariance principle, feed-forward compensation is developed by pole-zero placement theory for the system. The task is accomplished by transforming instable zero of the system into pole of the fitted closed-loop transfer function, forming the zero...

Yao Jian-jun; Di Duo-tao; Jiang Gui-lin; Liu Sheng

2012-01-01

46

Application of sliding mode control to a hydraulic system; Sliding mode seigyo no yuatsu system eno tekiyo jirei  

Energy Technology Data Exchange (ETDEWEB)

This paper explains a case of applying the sliding mode control theory to an angle position control system in a hydraulic servo system driving inertia load and torque load. There are various methods for designing the sliding mode, each having good control performance. However, executing the control law as it is may generate chattering. The chattering is caused mainly from excitation of the high-order mode which has been ignored when introducing the controller model. Effective means to suppress the chattering include limitation of frequency band in the control input and use of a robust observer. The sliding mode control to limit the frequency band in the control input generates no chattering in a system in which a servo valve and a hydraulic motor are connected with a relatively long pipe, evidencing its effect. In addition, use of a disturbance observer can make the steady deviation nearly zero even when large steady disturbance is applied. (NEDO)

Yanada, H. [Toyohashi University of Technology, Aichi (Japan)

1999-09-15

47

Double Adaptive Fuzzy Sliding Mode Control Scheme for Electro-hydraulic Velocity Servo System  

Directory of Open Access Journals (Sweden)

Full Text Available Pointing on uncertainties in the velocity servo system, caused by servo system cant model accurately, may cause the deterioration of the control quality of the Electro-Hydraulic Velocity Servo System (EHVSS and even lead to its instability. An Double Adaptive Fuzzy Sliding Mode Control (DAFSMC algorithm is proposed for an EHVSS. The proposed control strategy has fast response and good disturbance rejection capability. The numerical simulation is presented to verify the effectiveness of the proposed control scheme. It is shown from the experimental results that the proposed controller offers several advantages such as fast response, good disturbance rejection capability, good velocity tracking capability and so forth. It is also revealed from simulation results that the proposed control strategy is valid for the EHVSS.

Shao Jiang Wang

2012-01-01

48

A switched energy saving position controller for variable-pressure electro-hydraulic servo systems.  

Science.gov (United States)

The electro-hydraulic servo system (EHSS) demonstrates a relatively low level of efficiency compared to other available actuation methods. The objective of this paper is to increase this efficiency by introducing a variable supply pressure into the system and controlling this pressure during the task of position tracking. For this purpose, an EHSS structure with controllable supply pressure is proposed and its dynamic model is derived from the basic laws of physics. A switching control structure is then proposed to control both the supply pressure and the cylinder position at the same time, in a way that reduces the overall energy consumption of the system. The stability of the proposed switching control system is guaranteed by proof, and its performance is verified by experimental testing. PMID:24882668

Tivay, Ali; Zareinejad, Mohammad; Rezaei, S Mehdi; Baghestan, Keivan

2014-07-01

49

Hydraulic system provides smooth control of large tracking and antenna drive systems at very low tracking rates  

Science.gov (United States)

Hydraulic system provides smooth control of large tracking and antenna drive systems at very low tracking rates. This configuration modifies a series connection of the drive motors with compensating orifices to offset the effects of drain line loss. Linearization of response by eliminating cogging or cyclic operation is thus obtained.

Parker, G. L.

1967-01-01

50

Deterministic Control Strategy for a Hybrid Hydraulic System with Intermediate Pressure Line  

OpenAIRE

The paper introduces a new hydraulic system for mobile machines based on a constant pressure system with the aim to increase the efficiency of actuation of hydraulic cylinders. Using a third pressure level located between high pressure and tank pressure called intermediate pressure the system enables additional pressure potentials from high pressure to intermediate pressure and from intermediate pressure to tank pressure. This reduces throttle losses at hydraulic cylinders when driven at low ...

Dengler, Peter; Geimer, Marcus; Dombrowski, Rene? Von

2012-01-01

51

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.

52

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

OpenAIRE

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 th...

Lingxiao Quan; Wei Zhang; Bin Yu; Liang Ha

2013-01-01

53

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

54

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

55

Development of adaptive control system using the fuzzy theory for thermal-hydraulic analysis code, AQUA  

International Nuclear Information System (INIS)

An adaptive control system using the Fuzzy theory has been implemented into the single-phase three-dimensional thermal-hydraulic analysis code AQUA. The system is designed to yield the optimum time step sizes as a control parameter. It fully utilizes the experiences accumulated by numerical experts: e.g., the use of a very small time step size when a symptom of instabilities appear. Asymtotic behaviors in the course of numerical integration due to AQUA are monitored by checking mass residual and relative variations for three velocity components u, v and w, turbulent parameters k and ? and enthalpy h every time step. The validity of overall idea could be interpreted by analogy with the fact experts in many industries are capable of operating plants without profound knowledge of the control characteristics. As a result of numerical experiments, the total CPU time has been reduced typically by 40% in comparison with the cases when the time step size is not controlled by the system. In general, the adaptive control system using the Fuzzy theory is an efficient measure to save computing efforts when one wishes to perform an extremely large scale simulation over a long transient time span. (author)

56

Simulation of the electro-hydraulic control system of a BWR-5  

International Nuclear Information System (INIS)

The methodology used to develop the mathematical models for the simulation of the principal turbine electro-hydraulic control of the Laguna Verde Nuclear Plant (LVNP) is presented in this report. The development of the systems mathematical model is based on the response curves of each of its elements. Therefore, little error is expected with respect to real results. On the other hand, due to the fact that the greater part of the systems dynamics is governed by first order differential equations the explicit solution method is used allowing to solve the equations algebraically. The model is validated by comparing real valves and the ones obtained through our model. The analogical and logical parts will be tested considering transitory and steady state situations. The results are presented as computer graphs

57

Hydraulic management in a soil moisture controlled SDI wastewater dispersal system in an Alabama black belt soil  

Science.gov (United States)

An experimental field moisture controlled subsurface drip irrigation (SDI) system was designed and installed as a field trial in a Vertisol in the Alabama Black Belt region for two years. The system was designed to start hydraulic dosing only when field moisture was below field capacity. Results sho...

58

Numerical calculation for flow field of servo-tube guided hydraulic control rod driving system  

International Nuclear Information System (INIS)

A new-style hydraulic control rod driving mechanism was put forward by using servo-tube control elements for the design of control rod driving mechanism. The results of numerical simulation by CFD program Fluent for flow field of hydraulic driving cylinder indicate that the bigger the outer diameter of servo-tube, the smaller the resistance coefficient of variable throttle orifice. The zero position gap of variable throttle orifice could be determined on 0.2 mm in the design. The pressure difference between the upper and nether surfaces of piston was mainly created by the throttle function of fixed throttle orifice. It can be effectively controlled by changing the gap of variable throttle orifice. And the lift force of driving cylinder is able to meet the requirement on the design load. (authors)

59

Thermo hydraulic analysis and control of the HELOKA water cooling system  

International Nuclear Information System (INIS)

In the framework of the European Fusion Program, various Helium cooled Test Blanket Modules (TBM), such as the Helium Cooled Pebble Bed (HCPB) blanket, are proposed for tests under reactor relevant experimental conditions in ITER. To qualify the TBM module design for ITER, it is necessary to test full size mock-ups in a helium loop under realistic pressure, temperature and flow conditions. The HCPB mock-ups will be tested at the Helium Loop Karlsruhe (HELOKA) test facility, at present in advanced status of design. As far as possible, HELOKA shall operate with requirements similar to those of the Helium coolant circuit of the TBM modules in ITER. One of the main requirements of the ITER main helium loop is its ancillary water cooling system, hence the need of a Water Cooling System (WCS) for HELOKA. An existing WCS, recently used for the COMET (Core Melt Accidents) experiment, is foreseen for this purpose. The system, designed in the 80's for a heat load of about 7 MW, will be used first for the HELOKA TBM experimental campaign, where the maximum expected heat load does not exceed 5 MW, and later on, for the Test Divertor Modules (TDM). The thermal hydraulic effect has been studied using the system code RELAP5, where the pumps, the heat exchanger (HX), the cooling tower, the valves, the piping, etc., can be modeled and the whole loop can be simulated for steady state, transient accident processes or cyclic operation. In order to improve the efficiency of the system and save energy, it has been proposed to install variable frequency converters for the electric drivers and new feedback controllers. An evaluation of the overall performances of the system with the proposed feedback controllers has been conducted with computer models developed with SIMULINK. At present most of the components have been modeled using manufacturer's data. For some components, technical data are scarce and therefore a comparison with experimental data to validate the models is planned. After the validation based on the experimental data, the code will allow the testing of the control strategies for steady state, transients or cyclic operation and check the possible upgrade of the system to 10 MW (expected heat load for the HELOKA TDM experimental campaign). The control system is being modernized using state of the art hardware and software components. The upgrade also includes additional sensors and a new data acquisition system. (author)

60

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

61

The study on the hydraulic control rod driving system in cyclical swing  

International Nuclear Information System (INIS)

This paper discusses the behavior of the hydraulic control rod driving system (HCRDS) in cyclical swing. The first generation HCRDS with the hole-hole step cylinder, the important driving component, has been applied in 5 MW nuclear heating reactor for several years and run well all along. The second generation with the chamfer-hole step cylinder has also been developed and studied. The HCRDS working principle, as well as the particular design of the hole-hole step cylinder, has been introduced in the paper. The control rod (CR) behavior when HCDRS vacillating in certain swing and cycle has been analyzed subsequently. The calculating result indicates that the CR can keep its balance in such unstable state and the operation of driving CR upwards or downwards can function properly likewise. In cyclical swing, the CR can drop down quickly and meet the reactor shut-down needs. The theoretical analysis proves the HCRDS reliable and safe, establishing basement for its further research and wide use

62

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

63

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

64

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

OpenAIRE

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 switchin...

Jin Baoquan; Chen Dongbing

2012-01-01

65

?????????????? ????????????? ??????????????? ??????? ??????????? ??????-??????? 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

66

Control rod driving hydraulic device  

International Nuclear Information System (INIS)

In a control rod driving hydraulic device for an improved BWR type reactor, a bypass pipeline is disposed being branched from a scram pipeline, and a control orifice and a throttle valve are interposed to the bypass pipeline for restricting pressure. Upon occurrence of scram, about 1/2 of water quantity flowing from an accumulator of a hydraulic control unit to the lower surface of a piston of control rod drives by way of a scram pipeline is controlled by the restricting orifice and the throttle valve, by which the water is discharged to a pump suction pipeline or other pipelines by way of the bypass pipeline. With such procedures, a function capable of simultaneously conducting scram for two control rod drives can be attained by one hydraulic control unit. Further, an excessive peak pressure generated by a water hammer phenomenon in the scram pipeline or the control rod drives upon occurrence of scram can be reduced. Deformation and failure due to the excessive peak pressure can be prevented, as well as vibrations and degradation of performance of relevant portions can be prevented. (N.H.)

67

Nonlinear modeling and identification of the electro-hydraulic control system of an excavator arm using BONL model  

Science.gov (United States)

Electro-hydraulic control systems are nonlinear in nature and their mathematic models have unknown parameters. Existing research of modeling and identification of the electro-hydraulic control system is mainly based on theoretical state space model, and the parameters identification is hard due to its demand on internal states measurement. Moreover, there are also some hard-to-model nonlinearities in theoretical model, which needs to be overcome. Modeling and identification of the electro-hydraulic control system of an excavator arm based on block-oriented nonlinear(BONL) models is investigated. The nonlinear state space model of the system is built first, and field tests are carried out to reveal the nonlinear characteristics of the system. Based on the physic insight into the system, three BONL models are adopted to describe the highly nonlinear system. The Hammerstein model is composed of a two-segment polynomial nonlinearity followed by a linear dynamic subsystem. The Hammerstein-Wiener(H-W) model is represented by the Hammerstein model in cascade with another single polynomial nonlinearity. A novel Pseudo-Hammerstein-Wiener(P-H-W) model is developed by replacing the single polynomial of the H-W model by a non-smooth backlash function. The key term separation principle is applied to simplify the BONL models into linear-in-parameters structures. Then, a modified recursive least square algorithm(MRLSA) with iterative estimation of internal variables is developed to identify the all the parameters simultaneously. The identification results demonstrate that the BONL models with two-segment polynomial nonlinearities are able to capture the system behavior, and the P-H-W model has the best prediction accuracy. Comparison experiments show that the velocity prediction error of the P-H-W model is reduced by 14%, 30% and 75% to the H-W model, Hammerstein model, and extended auto-regressive (ARX) model, respectively. This research is helpful in controller design, system monitoring and diagnosis.

Yan, Jun; Li, Bo; Guo, Gang; Zeng, Yonghua; Zhang, Meijun

2013-11-01

68

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

69

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)

70

Robust sampled-data control of hydraulic flight control actuators  

OpenAIRE

In todays flight-by-wire systems the primary flight control surfaces of modern commercial and transport aircraft are driven by electro hydraulic linear actuators. Changing flight conditions as well as nonlinear actuator dynamics may be interpreted as parameter uncertainties of the linear actuator model. This demands a robust design for the controller. Here the parameter space design is used for the direct sampled-data controller synthesis. Therefore, a static output controller is choosen, the...

Kliffken, Markus Gustav

1997-01-01

71

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

72

Pressure variable orifice for hydraulic control valve  

Science.gov (United States)

Hydraulic valve absorbs impact energy generated in docking or joining of two large bodies by controlling energy release to avoid jarring shock. The area of exit porting presented to the hydraulic control fluid is directly proportional to the pressure acting on the fluid.

Ammerman, R. L.

1968-01-01

73

Precision Force Control for an Electro-Hydraulic Press Machine  

OpenAIRE

This thesis is primarily intended to design a PC-based control system to control the force of an electro-hydraulic servo press system for implementing precision force control. The main feature is to develop a composite control by using the relief valve and the flow servo valve. Using feedback from a force sensor, a fuzzy controller was designed with LabVIEW software as the system control core for achieving a precision force control for the hydraulic cylinder on its travel and output. The weak...

Hong-Ming Chen; Guo-Wei Yang; Chong-Cyuan Liao

2014-01-01

74

Improved feedwater control through microprocessor based reactor feedpump turbine electro-hydraulic controls  

International Nuclear Information System (INIS)

Matched response between the feedwater control system and the reactor feedpump turbine (RFPT) control system enhances plant performance and cushions the interface between the turbine generator and feedwater systems. Digital control techniques, applied through the latest microprocessor technology, provide the flexibility to match characteristics of these systems. Most older systems use mechanical hydraulic governors utilizing a hydraulic supply common with the bearing lubrication system. Along with inherently slow dynamic responses, these systems are subject to contamination related control problems and associated high levels of maintenance. A retrofittable system is described that combines a conversion to a high pressure electro-hydraulic fluid system with microprocessor based control technology for improved feedwater system performance

75

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)

76

Design and verification of DNAPL hydraulic containment and control system adjacent to the Fraser River estuary, British Columbia  

Energy Technology Data Exchange (ETDEWEB)

A remediation program was underway at a former industrial site along the Fraser River near Vancouver, British Columbia from 1997 to 2002. As part of the remedial activity, a hydraulic containment and control system (HCCS) was designed and built in early 1999 to treat DNAPL (dense non-aqueous liquid phase) and dissolved-phase polycyclic aromatic hydrocarbons (PAHs) which migrated toward and beneath the river bed. The site is underlain by a series of permeable alluvial deposits. The groundwater flow is influenced by tidal fluctuations in the river and seasonal fluctuations in both groundwater and river levels. The HCCS was designed using an analytical model for flow of DNAPL on a sloping interface plus a numerical hydrogeological model called MODFLOW which accounted for the dynamic nature of the groundwater flow. Modelling showed that 5 containment wells pumping at a combined rate of 425 cubic metres per day would be sufficient to reverse the hydraulic gradient and stop the flow of contaminants towards the river. The wells were placed at optimum locations determined by the model. By 1999, 5 containment wells, 3 primary monitoring wells, and 3 DNAPL recovery wells were commissioned. Ongoing monitoring confirms that the HCCS is performing as predicted by the models. 4 refs., 1 tab., 8 figs.

Zawadzki, W.; Chorley, D.W.; O' Hara, G. [Golder Associates Ltd., Burnaby, BC (Canada)

2002-07-01

77

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

78

Precision Force Control for an Electro-Hydraulic Press Machine  

Directory of Open Access Journals (Sweden)

Full Text Available This thesis is primarily intended to design a PC-based control system to control the force of an electro-hydraulic servo press system for implementing precision force control. The main feature is to develop a composite control by using the relief valve and the flow servo valve. Using feedback from a force sensor, a fuzzy controller was designed with LabVIEW software as the system control core for achieving a precision force control for the hydraulic cylinder on its travel and output. The weakness of hydraulic systems is that hydraulic oil is compressible and prone to leaking, and its characteristics can vary with oil temperature, thus making it difficult for a general linear controller to achieve accurate control. Therefore, a fuzzy controller was designed with LabVIEW along with a NI-PCI_6221 interface card and a load cell to control the servo valve flow and the relief valve to control the pressure source. The testing results indicate that accurate force control output of an electro-hydraulic servo press system can be obtained.

Hong-Ming Chen

2014-08-01

79

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

80

Control of a hydraulic system by means of a fuzzy approach  

OpenAIRE

Non linear models can be represented conveniently by Takagi-Sugeno fuzzy models when nonlinearities are bounded. This approach uses a collection of linear models which are interpolated by non linear functions. Then the global control law is the interpolation by the same functions of each feedback associated to each linear model. A Lyapunov approach enables to compute these feedback gains. The number of linear models depends directly on the number of nonlinearities the system has. The more mod...

Mohamed Ksantini; Ameni Ellouze; Francois Delmotte

2013-01-01

81

Development of hydraulic brake actuator for active brake control; Active brake seigyoyo yuatsu booster no kaihatsu  

Energy Technology Data Exchange (ETDEWEB)

Recently, application of active brake control systems of the vehicle are increasing. (Vehicle stability control, Panic brake assist ) We have developed a new hydraulic brake actuator for active brake control systems. New hydraulic brake actuator is composed of the three parts. (Hydraulic booster unit, Power supply unit, Control valve unit) This report describes the construction of the new hydraulic booster unit. 2 refs., 10 figs.

Konishi, Y.; Hattori, M. Sugisawa, M.; Nishii, M. [Aisin Seiki Co. Ltd., Aichi (Japan)

1997-10-01

82

A Robust Adaptive Hydraulic Power Generation System for Jet Engines  

OpenAIRE

The paper presents an innovative hydraulic power generation system able to enhance performance, reliability and survivability of hydraulic systems used in military jet engines, as well as to allow a valuable power saving. This is obtained by a hydraulic power generation system architecture that uses variable pressure, smart control, emergency power source and suitable health management procedures. A key issue is to obtain all these functions while reducing to a minimum the number of additiona...

Ronco, Pierantonio; Sorli, Massimo; Mornacchi, Andrea; Jacazio, Giovanni

2013-01-01

83

Control system for the feed of pressurized fluid in a hydraulic circuit as a function of the state of the locking or unlocking of two mechanical organs  

International Nuclear Information System (INIS)

The control system comprises two hydraulic cylinders of which rods are integral with the mechanical organs. The piston of the first cylinder separates the chamber of this one in two parts. The piston of the second cylinder separates its chamber in three parts. The inlet chamber of the two cylinders are connected to pressurized fluid feed pipes, and the outlet chambers to a depressurization pipe. According to the position of the piston depending itself on the state of locking or unlocking of the rods, an interconnection pipe and a feed pipe of the pressurized fluid hydraulic circuit communicate with a chamber or another one. The feed of the hydraulic circuit is possible only the two rods are unlocked. The invention applies more particularly to the feed of the control circuit of an emergency seal of the primary pump of a pressurized water nuclear reactor

84

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

85

Experimental evaluation of control strategies for hydraulic servo robot  

DEFF Research Database (Denmark)

In this paper different linear and non-linear controllers applied to a hydraulically driven servo robot are evaluated and validated. The task is to make the actuators of the manipulator track a position reference with minimum error. Hydraulic systems are intrinsically non-linear and using linear control techniques typically results in conservatively dimensioned controllers to obtain stable performance. Non-linear control techniques have the potential of overcoming these problems and in this paper the focus is on applying simple nonlinear robust and adaptive controllers feasible for implementation in industrial servo drives. The different controllers are compared and evaluated from simulation and experimental results.

Bech, Michael MØller; Andersen, Torben Ole

2013-01-01

86

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

87

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

OpenAIRE

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 operat...

Walter Kucharczyk; Goldenberg, Andrew A.; Cyrus Raoufi

2008-01-01

88

System Design and Performance Test of Hydraulic Intensifier  

International Nuclear Information System (INIS)

Components such as pressure vessel, hydraulic hose assembly, accumulator, hydraulic cylinder, hydraulic valve, pipe, etc., are tested under the impulse-pressure conditions prescribed in ISO and SAE standards. The impulse pressure test machine needs to have a high pressure, a precise control system and a long life. It should satisfy the requirements for fabrication of the impulse tester to generate ultra high pressure in the hydraulic system. In the impulse tester, a servo-valve control system is adopted; although the control application is convenient, it is expensive owing to the cost of developing the system. The type of the control system determines the pressure wave, which affects the components that are tested. In this study, the manufacturing process and the intensifier system design related to the flow, pressure, and the increasing rate of pressure are investigated. The results indicate the ultra high pressure waves in the system

89

Intelligent PI Fuzzy Control of An Electro-Hydraulic Manipulator  

OpenAIRE

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 ...

Aly, Ayman A.; Abo El-lail, Aly S.; Shoush, Kamel A.; Salem, Farhan A.

2012-01-01

90

Crosshole investigations - Design of the hydraulic testing system  

International Nuclear Information System (INIS)

Hydraulic testing, especially using sinusoidal signals, is one component of the Crosshole Investigations at the Stripa Mine which will characterise a volume of rock located 360 metres below ground level. This paper describes the equipment which performs the hydraulic tests by creating and measuring signals in isolated sections of two boreholes. The system is computer controlled and some programming information is included

91

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

92

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

93

Modelling and control of a high performance electro-hydraulic test bench  

OpenAIRE

Hydraulic systems are widely applied in industry for position or force control. However, due to hydraulic system nonlinearities, it is difficult to achieve a precise model valid over a large range of frequencies and movements. The work in this dissertation focuses on a high performance hydraulic test bench which involves three main hydraulic components, i.e. two high performance servovalves, a double rod actuator, and a specific intermediate block connecting the servovalves and actuator. This...

Xu, Yaozhong

2013-01-01

94

Rotary valve controls multiple hydraulic leveling cylinders  

Science.gov (United States)

Single rotary valve controls a circular bank of hydraulic leveling cylinders that must maintain large loads within plus or minus three arc minutes of the true vertical. Since the position of the valve spool determines the flow rate of each bank of cylinders and hence cylinder position, different flow rates may be obtained by changing the spool shape.

1966-01-01

95

Model Reference PID Control of an Electro-hydraulic Drive  

Directory of Open Access Journals (Sweden)

Full Text Available Hydraulic cranes are inherently nonlinear and contain components exhibiting strong friction, saturation, variable inertia mechanical loads, etc. The characteristics of these non-linear components are usually not known exactly as structure or parameters. For these reasons, tuning of the traditional PID controller parameters to control this system for the required performance faces a strong challenge. In this paper a new approach to design an adaptive PID control has the ability to solve the control problem of highly nonlinear systems such as the hydraulic crane was proposed. The core of the design method depends on comparing the performance of the Model Reference (MR response with the nonlinear model response and feeding an adaptation signal to the PID control system to eliminate the error in between. It is found that the proposed MR-PID control policy provided the most consistent performance in terms of rise time and settling time regardless of the nonlinearities.

Ayman A. Aly

2012-10-01

96

Robust Control of a Hydraulically Actuated Manipulator Using Sliding Mode Control  

DEFF Research Database (Denmark)

This paper presents an approach to robust control called sliding mode control (SMC) applied to the a hydraulic servo system (HSS), consisting of a servo valve controlled symmetrical cylinder. The motivation for applying sliding mode control to hydraulically actuated systems is its robustness towards structured (parametric) and unstructured (unmodeled dynamics) uncertainties. A third-order model of the actuated system is used to develop a sliding mode control which is implemented and tested on a simulation model. To avoid measurement of velocity and acceleration a simple first-order model is furthermore used to develop a simple sliding mode control (SSMC). The performance of the two controllers are compared and discussed.

Hansen, Michael Rygaard; Andersen, Torben Ole

2005-01-01

97

Technology and control for hydraulic manipulators  

International Nuclear Information System (INIS)

Hydraulic manipulators are candidate for fusion reactor maintenance. Their main advantages are their large payload with respect to volume and mass, their reliability and their robustness. However, due to their force control limitations, they are disqualified for precise manipulation and are dangerous for the environment and themselves in case of unexpected collision. CEA, in collaboration with CYBERNETIX and IFREMER has developed the advanced hydraulic robot MAESTRO. Force and hybrid control has been developed in order to avoid the previous problems. Using 'pressure' control servo-valve instead of the standard 'flow' control servo-valve (standard configuration of the MAESTRO) makes a real simplification of the control loop. No more pressure sensors are needed for monitoring the hydraulic joint in force control mode and using this kind of valves makes big safety improvements. The French company IN-LHC, designed and manufactured a prototype of servo-valve that fits the performances and space constraints of the Maestro arm. A characterisation of this new product was made on a mock-up and a set of these prototypes integrated in the Maestro slave-arm. A comparison between the two actuating technologies was made and showed that the performances of the pressure servo-valves make it applicable to general application

98

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

99

Model Reference PID Control of an Electro-hydraulic Drive  

OpenAIRE

Hydraulic cranes are inherently nonlinear and contain components exhibiting strong friction, saturation, variable inertia mechanical loads, etc. The characteristics of these non-linear components are usually not known exactly as structure or parameters. For these reasons, tuning of the traditional PID controller parameters to control this system for the required performance faces a strong challenge. In this paper a new approach to design an adaptive PID control has the ability to solve the co...

Aly, Ayman A.

2012-01-01

100

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

101

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

102

Analysis on vibration signal of pipeline for hydraulic exciting system  

Science.gov (United States)

Hydraulic exciting system consisted of pipeline and wave-exciter has been constructed to study hydraulic pipeline vibration control laws. Through controlling the inverter frequency conversion, opening and closing of the shock device produce periodic vibration in hydraulic pipe.The excitation test system is established. The vibration signals on different point of pipeline have been collected and analyzed to come to the law of pipeline vibration. The results show that pipeline vibration frequency decreases with the system pressure increaseing in the same excitation frequency; when frequency and pressure are determined, the vibration waveforms of different point on pipe are the same, almost nonexistent phase differences, but they are inconsistent with amplitudes on different points. Pipe vibration close to the hydraulic cylinder is slightly intenser than that near the wave-exciter.

Wei, Xiu-ye; Zhang, Hui-xian; Lu, Chun-yue; Lu, Zi-rong

2012-04-01

103

Analysis of buffering process of control rod hydraulic absorber  

International Nuclear Information System (INIS)

Control Rod Hydraulic Drive Mechanism(CRHDM) is a newly invented build-in control rod drive mechanism. Hydraulic absorber is the key part of this mechanism, and is used to cushion the control rod when the rod scrams. Thus, it prevents the control rod from being deformed and damaged. In this paper dynamics program ANSYS CFX is used to calculate all kinds of flow conditions in hydraulic absorber to obtain its hydraulic characteristics. Based on the flow resistance coefficients obtained from the simulation results, fluid mass and momentum equations were developed to get the trend of pressure change in the hydraulic cylinder and the displacement of the piston rod during the buffering process of the control rod. The results obtained in this paper indicate that the hydraulic absorber meets the design requirement. The work in this paper will be helpful for the design and optimization of the control rod hydraulic absorber. (author)

104

46 CFR 28.880 - Hydraulic equipment.  

Science.gov (United States)

...All material in a hydraulic system must be suitable for use with the hydraulic fluid used and...steering equipment, controls for operating hydraulic...or sudden loss of control due to loss of hydraulic system pressure. A...

2010-10-01

105

Design of a fractional order PID controller for hydraulic turbine regulating system using chaotic non-dominated sorting genetic algorithm II  

International Nuclear Information System (INIS)

Highlights: • Multi-objective optimization based fractional order controller is designed for HTRS. • NSGAII is improved by iterative chaotic map with infinite collapses (ICMIC) operator. • ISE and ITSE are as chosen as objective functions in tuning parameters of HTRS. • FOPID controller outperforms the PID controller under various running conditions. • Trade-off between speed of reference tracking and damping of oscillation are shown. - Abstract: Fractional-order PID (FOPID) controller is a generalization of traditional PID controller using fractional calculus. Compared to the traditional PID controller, in FOPID controller, the order of derivative portion and integral portion is not integer, which provides more flexibility in achieving control objectives. Design stage of such an FOPID controller consists of determining five parameters, i.e. proportional, integral and derivative gains {Kp, Ki, Kd}, and extra integration and differentiation orders {?,?}, which has a large difference comparing with the conventional PID tuning rules, thus a suitable optimization algorithm is essential to the parameters tuning of FOPID controller. This paper focuses on the design of the FOPID controller using chaotic non-dominated sorting genetic algorithm II (NSGAII) for hydraulic turbine regulating system (HTRS). The parameters chosen of the FOPID controller is formulated as a multi-objective optimization problem, in which the objective functions are composed by the integral of the squared error (ISE) and integral of the time multiplied squared error (ITSE). The chaotic NSGAII algorithm, which is an incorporation of chaotic behaviors into NSGAII, is used as the optimizer to search true Pareto-front of the FOPID controller and designers can implement each of them based on objective functions priority. The designed chaotic NSGAII based FOPID controller procedure is applied to a HTRS system. A comparison study between the optimum integer order PID controller and optimum fractional order PID controller is presented in the paper. The simulation and some experimental results validate the superiority of the fractional order controllers over the integer controllers

106

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.

107

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)

108

High speed on/off valve control hydraulic propeller  

Science.gov (United States)

The work-class remotely-operated-underwater-vehicles (ROVs) are mainly driven by hydraulic propulsion system, and the effeciency of hydraulic propulsion system is an important performance index of ROVs. However, the efficiency of traditional hydraulic propulsion system controlled by throttle valves is too low. Therefore, in this paper, for small and medium ROVs, a novel propulsion system with higher efficiency based on high speed on/off valve control hydraulic propeller is proposed. To solve the conflict between large flow rate and high frequency response performance, a two-stage high speed on/off valve-motor unit with large flow rate and high response speed simultaneously is developed. Through theoretical analysis, an effective fluctuation control method and a novel pulse-width-pulse-frequency-modulation (PWPFM) are introduced to solve the conflict among inherently fluctuation, valve dynamic performance and system efficiency. A simulation model is established to evaluate the system performance. To prove the advantage of system in energy saving, and test the dynamic control performance of high speed on/off valve control propeller, a test setup is developed and a series of comparative experiments is completed. The smimulation and experiment results show that the two-stage high speed on/off valve has an excellent dynamic response performance, and can be used to realize high accuracy speed control. The experiment results prove that the new propulsion system has much more advantages than the traditional throttle speed regulation system in energy saving. The lowest efficiency is more than 40%. The application results on a ROV indicate that the high speed on/off valve control propeller system has good dynamic and steady-state control performances. Its transient time is only about 1 s-1.5 s, and steady-state error is less than 5%. Meanwhile, the speed fluctuation is small, and the smooth propeller speed control effect is obtained. On the premise of good propeller speed control performance, the proposed high speed on/off valve control propeller can improve the effeciency of ROV propulsion system significantly, and provides another attractive ROV propulsion system choice for engineers.

Zhu, Kangwu; Gu, Linyi; Chen, Yuanjie; Li, Wei

2012-05-01

109

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

110

Analysis of an controller design for an electro-hydraulic servo pressure regulator  

DEFF Research Database (Denmark)

Mobile hydraulics is in a transition phase, where electronic sensors and digital signal processors are starting to become standard on a high number of machines, hereby replacing hydraulic pilot lines and oering new possibilities with regard to both control and feasibility. For controlling some of the existing hydraulic components there are, however, still a need for being able to generate a hydraulic pilot pressure, as e.g. almost all open-circuit pumps are hydraulically controlled. The focus of the current paper is therefore on the analysis and controller design an electro-hydraulic servo pressure regulator, which generates a hydraulic LS-pressure based on an electrical reference, hereby synergistically integrating knowledge from all parts of the mechatronics area. The servo pressure regulator is used to generate the LS-signal for a variable displacement pump, and the paper rst presents the considered system and an experimentally veried model of this. A linearized model is then presented, which comprisethe basis for a stability and sensitivity analysis of the system. Based on the results of the analysis, a control strategy is designed in combination with optimisation of the mechanical design to generate a controlled leakage  ow that aids in stabilising the system. The robustness of the system is then discussed in relation to dierent pilot line volumes and pump dynamics. Finally experimental results are presented, where the performance is compared to that of a similar hydraulic reference system, which has been the basis for the specification of performance requirements.

Pedersen, Henrik C.; Andersen, Torben Ole

2009-01-01

111

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

112

Hydraulic control device for control rod drives  

International Nuclear Information System (INIS)

Purpose: To enable control rod insertion and extraction in a predetermined time with no effects from pressure variations in the reactor. Constitution: The pressure conditions in the reactor are detected by a pressure generator and the detected value is inputted to a pressure compensator. An adequate signal corresponding to the changes in the flow rate resulted from the changes in the reactor pressure is set and compensated in the pressure compensator. The proportional gain in a flow rate indication regulator is thus made pressure-dependent and the total gain can be obtained always at a certain level irrespective of the reactor pressure. (Ikeda, J.)

113

Robust force control in a novel electro-hydraulic structure using polytopic uncertainty representation.  

Science.gov (United States)

Electro-hydraulic servo systems (EHSS) are used in many industrial applications for position and force control. Force control with a hydraulic actuator is challenging and requires complicated control algorithms used along with high crossover frequency electro-hydraulic valves, even for simple force control tasks. In this paper, a different hydraulic structure is proposed to improve the force tracking quality and increase efficiency in the EHSS. This comes at the cost of a new model with linearization and uncertainty challenges. To address these challenges, a robust H? control design approach is followed to control the proposed EHSS. Model linearization uncertainties are approximated by a polytope and a robust controller is designed to keep the system stable and satisfy the H? performance conditions within this polytope. Experimental results verify that the objectives of the paper are satisfied after using the proposed system. PMID:25160870

Baghestan, K; Rezaei, S M; Talebi, H A; Zareinejad, M

2014-11-01

114

Control rod drive system hydraulic transient analytical and transient test results for James A. FitzPatrick BWR plant  

International Nuclear Information System (INIS)

On October 14, 1981, Reactor Control, Inc., the supplier of the Control Rod Drive (CRD) System, informed the NRC that the rapid opening of insert scram valves could potentially result in a significant waterhammer transient affecting the CRD insert lines and supports in several BWR plants. As a result, all BWR plants are addressing this issue by performing analyses and tests to determine the effect of waterhammer loads on the CRD system during a scram event. The FitzPatrick plant has been operating for approximately 10 years and has experienced a sizeable number of scram events with no apparent effect on the CRD system piping and supports. This is indicative that the CRD system is capable of withstanding the waterhammer loads. The objective of this project was to upgrade the system, if needed, but to avoid expenditure of resources and manrem exposure on modifications that would not yield a gain in safety. This objective was accomplished by a combination of computer analyses and in-plant tests to realistically predict the system structure behavior under waterhammer loads. This approach would indicate that the system is adequately designed or would identify the modification needed. (orig.)

115

Hydraulic Regenerative System for a Light Vehicle  

OpenAIRE

The thesis is based in a constructed light vehicle that must be improved by adding a hydraulic energy recovery system. This vehicle named as TrecoLiTH, participated in the Formula Electric and Hybrid competition (Formula EHI) 2009 in Italy -Rome- and won several awards. This system consists in two hydraulic motors hub mounted which are used to store fluid at high pressure in an accumulator when braking. Through a valve the pressure will flow from the high pressure accumulator to the low press...

Guinart Trayter, Xavier; Orpella Aceret, Jordi

2010-01-01

116

Experimental Verification of Fault Predictions in High Pressure Hydraulic Systems  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper a model of a high pressure hydraulic system was developed to simulate the effect of increased internal leakages inside the hydraulic cylinder and the 4/2 way directional control valve and to calculate the main parameters of the hydraulic system under various loads through the use of leakage-simulating throttle valves. After the completion of modeling, the throttle valves that simulate the internal leakages were calibrated and a number of test runs were performed for the cases of normal operation and the operation with increased internal leakages. The theoretical predictions were compared against the experimental results from an actual hydraulic test platform installed in the laboratory. In all cases, modeling and experimental data curves correlate very well in form, magnitude and response times for all the system’s main parameters. This proves that the present modeling can be used to accurately predict various faults in hydraulic systems, and can thus be used for proactive fault finding in many cases, especially when the defective component is not easily detected and obvious at first sight.

P. Athanasatos

2014-05-01

117

HYDRAULIC REDISTRIBUTION IN THE PACIFIC NORTHWEST: TWEAKING THE SYSTEM  

Science.gov (United States)

Hydraulic redistribution (HR) has recently been documented in Pacific Northwest forests, but the controls governing this process and its importance to shallow-rooted species are poorly understood. Our objective in this study was to manipulate the soil-root system to tease apart ...

118

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

119

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

120

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

121

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

122

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

123

Common cause failure analysis of hydraulic scram and control rod systems in the Swedish and Finnish BWR plants  

International Nuclear Information System (INIS)

The main task of the project included the analysis of the operating experiences at the BWRs of ABB Atom design, comprising 9 units in Sweden and 2 in Finland. International experience and reference information were also surveyed. A reference application was done for the Barsebaeck plant. This pilot study covered all systems which contribute to the reactor shutdown, including also the actuation relays at the interface to the reactor protection system. The Common Load Model was used as the quantification method, which proved to be a practicable approach. This method provides a consistent handling of failure combinatorics and workable extension to evaluate localized dependence between adjacent control rod and drive assemblies (CRDAs). As part of this project, instructions of handbook style were prepared for the CCF analysis of high redundancy systems. The primary focus in the analysis of operating experience was placed on the scram valves and CRDAs. Due to the limited component population, the experiences for the scram valve constitute only a few single failures and some potential but none actual CCF event. These insights are compatible with the generic data for these valves. The experiences for the CRDAs include several single failures, and some actual and many potential CCF events of varying degree of functional impact. Special emphasis was placed to identify any multiple failure or degradation indicating that adjacent rods would be more vulnerable to failure, because such phenomena are far more critical for the scram function as compared to failure of randomly placed rods. 17 refs

124

Hydraulic brake-system for a bicycle:  

OpenAIRE

The invention relates to a hydraulic brake system for a bicycle which may or may not be provided with an auxiliary motor, comprising a brake disc and brake claws cooperating with the brake disc, as well as fluid-containing channels (4,6) that extend between an operating organ (1) and the brake claws, and which system further possesses a spring-loaded pistion (11) accommodated and moveable in a first chamber (13).

Frankenhuyzen, J.

2007-01-01

125

Dynamic analysis of upper hydraulic drive control rod under vibration conditions  

International Nuclear Information System (INIS)

The paper studies the dynamic response of the hydraulically driven control rod (HDCR) under vibration conditions. The governing equation of the hydraulic driving system in a non-inertial coordinate system was deduced using a characteristic method. By comparing the analysis with the experiment, the analysis program was validated. It is shown that the response of a hydraulic driving system under a dissimilar vibration load is different. Under the condition of the pulse loading with a higher acceleration and short period, the response amplitude of the control rod mainly depends on the input displacement and increases with its increase. The response amplitude is also related to the loading direction. The pulse loading in a downward direction causes the higher response of HDCR. Under the condition of an ocean wave with a lower acceleration and long period ocean wave, the response amplitude is small, and the hydraulic drive system can keep the control rod stable by self regulating. (author)

126

Hydraulic Press with LS System for Modelling of Plastic Working Operations  

Directory of Open Access Journals (Sweden)

Full Text Available 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

2008-03-01

127

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

128

Reliability design for impact vibration of hydraulic pressure pipeline systems  

Science.gov (United States)

The research of reliability design for impact vibration of hydraulic pressure pipeline systems is still in the primary stage, and the research of quantitative reliability of hydraulic components and system is still incomplete. On the condition of having obtained the numerical characteristics of basic random parameters, several techniques and methods including the probability statistical theory, hydraulic technique and stochastic perturbation method are employed to carry out the reliability design for impact vibration of the hydraulic pressure system. Considering the instantaneous pressure pulse of hydraulic impact in pipeline, the reliability analysis model of hydraulic pipeline system is established, and the reliability-based optimization design method is presented. The proposed method can reflect the inherent reliability of hydraulic pipe system exactly, and the desired result is obtained. The reliability design of hydraulic pipeline system is achieved by computer programs and the reliability design information of hydraulic pipeline system is obtained. This research proposes a reliability design method, which can solve the problem of the reliability-based optimization design for the hydraulic pressure system with impact vibration practically and effectively, and enhance the quantitative research on the reliability design of hydraulic pipeline system. The proposed method has generality for the reliability optimization design of hydraulic pipeline system.

Zhang, Tianxiao; Liu, Xinhui

2013-09-01

129

Hydraulic characteristics in top entry system  

International Nuclear Information System (INIS)

The top entry system is an advanced type of system from the conventional loop type LMFBR, which constitutes the primary reactor cooling loops by installing inverted U-shaped pipes between the reactor vessel (R/V), intermediate heat exchanger (IHX) and primary pumps. Therefore, thermal hydraulic tests paying attention to the thermal stratification phenomena (water test and sodium test) were conducted by using scale models of the system to obtain the thermal transient conditions, thermal head relating to natural circulation and knowledge about the effect of the difference in the physical properties between water and sodium. The following results were obtained: (1) It is estimated that there is no problem with thermal hydraulics in the Top Entry System. Thermal stratification at the inverted U-shaped pipes would not occur under the actual plant conditions. (2) Thermal hydraulic characteristics under the decay heat removal conditions by natural circulation of coolant were obtained. These results confirmed the feasibility of the top entry system. (author)

130

Mathematical Models of Hydraulic Systems, Examples, Analysis.  

Czech Academy of Sciences Publication Activity Database

Praha : ÚT AV ?R, 2006 - (P?íhoda, J.; Kozel, K.), s. 159-162 ISBN 80-85918-98-6. [Conference Topical Problems of Fluid Mechanics 2006. Praha (CZ), 22.02.2006-24.02.2006] R&D Projects: GA ?R(CZ) GA201/05/0005 Institutional research plan: CEZ:AV0Z10190503 Keywords : hydraulic systems * fluid flow * mathematical models Subject RIV: BA - General Mathematics

Straškraba, Ivan

131

Hydraulic Characteristics of the Maria Reactor Control Rod Seat  

International Nuclear Information System (INIS)

In the work a method and the results of hydraulic measurements accomplished on a mock up of the MARIA reactor control rod are presented. Based on the results received the mathematical equations describing the relations between water velocity in both seat gaps and the pressure drop on beryllium - graphite matrix as well as water temperature were determined. The results enable to perform a more precise thermal - hydraulic analysis of working conditions for the MARIA reactor control rods. (author)

132

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

133

A conceptual model of check dam hydraulics for gully control  

Science.gov (United States)

There is little information in scientific literature regarding the modifications induced by check dam systems in flow regimes in restored gully reaches, despite it being a crucial issue for the design of conservation measures. Here, we develop a conceptual model to classify flow regimes in straight rectangular channels for initial and dam-filling conditions as well as a method of estimating efficiency in order to provide guidelines for optimal design. The model integrates several previous mathematical approaches for assessing the main processes involved (hydraulic jump HJ, impact flow, gradually varied flows). Its performance was compared with the simulations obtained from IBER, a bi-dimensional hydrodynamic model. The impact of check dam spacing (defined by the geometric factor of influence c) on efficiency was explored. Eleven main classifications of flow regimes were identified depending on the element and level of influence. The model produced similar results when compared with IBER, but led to higher estimations of HJ and impact lengths. Total influence guaranteed maximum efficiency and HJ control defining the location of the optimal c. Geometric total influence (c = 1) was a valid criterion for the different stages of the structures in a wide range of situations provided that hydraulic roughness conditions remained high within the gully, e.g. through revegetation. Our total influence criterion involved shorter spacing than that habitually recommended in technical manuals for restoration, but was in line with those values found in spontaneous and stable step-pools systems, which might serve as a reference for man-made interventions.

Castillo, C.; Pérez, R.; Gómez, J. A.

2013-09-01

134

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

135

LQG Control of a Hydraulic Actuator with a Flexible Mechanical Load  

OpenAIRE

This paper presents a control system based on linear quadratic state feedback and state estimation for an hydraulic actuator with a flexible mechanical load. The purpose of the control system is to improve the dynamic properties by reducing the oscillatory behavior of the load and to eliminate the steady state error in the load position caused by external disturbances. Using a simplified linear model a control system is developed and evaluated using simulations and experiments.

Gunnarsson, Svante; Krus, Petter

1993-01-01

136

Borehole hydraulic coal mining system analysis  

Science.gov (United States)

The borehole hydraulic coal mining system accesses the coal seam through a hole drilled in the overburden. The mining device is lowered through the hole into the coal seam where it fragments the coal with high pressure water jets which pump it to the surface as a slurry by a jet pump located in the center of the mining device. The coal slurry is then injected into a pipeline for transport to the preparation plant. The system was analyzed for performance in the thick, shallow coal seams of Wyoming, and the steeply pitching seams of western Colorado. Considered were all the aspects of the mining operation for a 20-year mine life, producing 2,640,000 tons/yr. Effects on the environment and the cost of restoration, as well as concern for health and safety, were studied. Assumptions for design of the mine, the analytical method, and results of the analysis are detailed.

Floyd, E. L.

1977-01-01

137

Thermal hydraulic modeling of integrated cooling water systems  

International Nuclear Information System (INIS)

Thermal hydraulic modeling of cooling water systems has been extended to multiple system configurations with heat exchangers as interface components between systems. The computer program PC-TRAX has been used as the basic tool for the system simulation. Additional heat exchanger modules have been incorporated to accurately predict the thermal performance of systems for the design as well as off-design conditions. The modeling accommodates time-dependent changes in conditions, temperature and pressure controllers, and detailed physical parameters of the heat exchangers. The modeling has been illustrated with examples from actual plant systems. An integrated system consisting of Spent Fuel Pool, Primary Component Cooling Water, and Service Water System has been successfully modeled to predict their performance under normal operations and emergency conditions. System configurations are changed from the base model by using a command module

138

Analysis of an controller design for an electro-hydraulic servo pressure regulator  

OpenAIRE

Mobile hydraulics is in a transition phase, where electronic sensors and digital signal processors are starting to become standard on a high number of machines, hereby replacing hydraulic pilot lines and oering new possibilities with regard to both control and feasibility. For controlling some of the existing hydraulic components there are, however, still a need for being able to generate a hydraulic pilot pressure, as e.g. almost all open-circuit pumps are hydraulically controlled. The focus...

Pedersen, Henrik C.; Andersen, Torben Ole; Madsen, A. M.; Dahl, M.; Nielsen, B. K.; Stubkier, Søren

2010-01-01

139

Boosted PWM open loop control of hydraulic proportional valves  

International Nuclear Information System (INIS)

This paper presents an innovative open loop control technique for direct single stage hydraulic proportional valves whose response rate is significantly higher than that obtained by standard open loop control techniques, even comparable to more costly commercial closed loop systems. Different from standard open loop techniques, which provide the coil with a constant current proportional to the target position, the control strategy proposed in this paper employs the peak and hold (P and H) technique, widely used in Diesel engine modern supply systems, to boost the duty cycle value of the pulse width modulation (PWM) signal for a short time, namely during the spool displacement, while maintaining a lower duty cycle for holding the spool in the required opening position. The developed 'boosted PWM' technique only requires a low cost microcontroller, such as a peripheral interface controller (PIC) equipped with a metal oxide semiconductor (MOS) power driver. The PWM parameters are calibrated as a function of the spool displacement so as to maximize the response rate without introducing overshoots: the collected data are stored in the PIC. Different valve opening procedures with step response have been compared to demonstrate the merits of the proposed boosted PWM technique. No overshoots have been registered. Moreover, the proposed method is characterized by a significantly higher response rate with respect to a standard open loop control, which approximately has the same control, which approximately has the same cost. Similar experimental tests show that the proposed boosted PWM technique has a response rate even higher than that provided by the more costly commercial closed loop system mounted on the valve, and it produces no overshoots

140

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

141

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

142

New requirements for hydraulic control fluids and discharge to sea gives unexpected operational problems  

Energy Technology Data Exchange (ETDEWEB)

Objective: Replacing existing hydraulic control fluids at all Statoils Subsea Installations to meet the new SFT requirements 1) What makes the change of fluid so sensitive regarding system-operability and long term reliability. Statoil's subsea hydraulic control fluids are basicly water based fluids with approximately 90% water/glycol content, the remaining 10% are additives to contribute to lubricity, general properties and long term stability. Having close to 300 different materials making interactions between each other and the properties of the hydraulic fluid, make any reactions difficult to predict. (chemical/ and galvanic reactions). 2) The consequences of failing in replacing the existing hydraulic fluids could be a full stop in part of Statoils subsea production. Some facts about the hydraulic fluids are presented. The study concludes that the investments of millions NOK and the time and focus from specialists and engineers from the major suppliers (and the oil-industri), have not only contributed to an environmentally better product, but also to a much better understanding of the complexity in the design of more acceptable hydraulic control-fluids. (Author)

Soerum, Anders

2006-03-15

143

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

144

Engine including hydraulically actuated valvetrain and method of valve overlap control  

Science.gov (United States)

An exhaust valve control method may include displacing an exhaust valve in communication with the combustion chamber of an engine to an open position using a hydraulic exhaust valve actuation system and returning the exhaust valve to a closed position using the hydraulic exhaust valve actuation assembly. During closing, the exhaust valve may be displaced for a first duration from the open position to an intermediate closing position at a first velocity by operating the hydraulic exhaust valve actuation assembly in a first mode. The exhaust valve may be displaced for a second duration greater than the first duration from the intermediate closing position to a fully closed position at a second velocity at least eighty percent less than the first velocity by operating the hydraulic exhaust valve actuation assembly in a second mode.

Cowgill, Joel (White Lake, MI)

2012-05-08

145

Design of Pumps for Water Hydraulic Systems  

DEFF Research Database (Denmark)

This paper considers the development of two pumps for water hydraulic applications. The pumps are based on two different working principles: The Vane-type pump and the Gear-type pump. Emphasis is put on the considerations that should be made to account for water as the hydraulic fluid.KEYWORDS: water, pump, design, vane, gear.

Klit, Peder; Olsen, Stefan

1999-01-01

146

Acceptance Test Report for 241-SY Pump Cradle Hydraulic System  

International Nuclear Information System (INIS)

The purpose of this ATP is to verify that hydraulic system/cylinder procured to replace the cable/winch system on the 101-SY Mitigation Pump cradle assembly fulfills its functional requirements for raising and lowering the cradle assembly between 70 and 90 degrees, both with and without pump. A system design review was performed on the 101-SY Cradle Hydraulic System by the vendor before shipping (See WHC-SD-WM-DRR-045, 241-SY-101 Cradle Hydraulic System Design Review). The scope of this plan focuses on verification of the systems ability to rotate the cradle assembly and any load through the required range of motion

147

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

148

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

149

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

150

Development of A Hydraulic Drive for a novel Diesel-Hydraulic system for Large commercial Vehicles  

DEFF Research Database (Denmark)

The objectives and results of the research project Hybrid Diesel-Hydraulic System for Large commercial vehicles, e.g. urban freight delivery, buses or garbage trucks. The paper presents and discusses the research and development of the system, modelling approach and results from preliminary performance tests on a 10 ton vehicle.

Stecki, J. S.; Conrad, Finn

2002-01-01

151

Geosiphon(TM) Ground Water Remediation System Hydraulics  

International Nuclear Information System (INIS)

Two, pilot-scale, GeoSiphon(TM) systems have been installed and tested for the treatment of contaminated ground water at the Savannah River Site (SRS). These systems consisted of an in situ treatment cell located in an area of higher hydraulic head and a siphon connecting the cell to a surface stream at a lower hydraulic head. The siphon induced contaminated ground water flow through a permeable treatment media in the cells and transported the treated water to the discharge points in a surface stream. The hydraulic head available to drive the systems is divided between the head losses associated with the treatment cell and siphon. Six different treatment cell configurations and seven different siphon configurations have been hydraulically evaluated in association with both pilot-scale systems. The results provide valuable guidelines for the design of GeoSiphon systems

152

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

153

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)

154

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

155

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

156

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

157

Modeling and control of a hydraulically actuated flexible-prismatic link robot  

International Nuclear Information System (INIS)

Most of the research related to flexible link manipulators 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. This manuscript describes a new hydraulically actuated, long reach manipulator with a flexible prismatic link at Oak Ridge National Laboratory (ORNL). Focus is directed towards both modeling and control of hydraulic actuators as well as flexible links that have variable natural frequencies

158

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

159

Interrelationship between stomatal conductance and xylem hydraulic conductivity on transpiration control in water stressed grapevines.  

OpenAIRE

Stomatal conductance and root conductivity have been considered the main controlling factors of water flow in the plant. However, structure and efficiency of the xylem transport system can affect water movement. If exposed to water stress, plants reduce water flow rate decreasing the conductivity components of the transpiration pathway. The objective of this work was to investigate on the relative importance of hydraulic canopy conductivity versus stomatal conductance on the control of wat...

Lovisolo, Claudio; Schubert, Andrea

2000-01-01

160

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

161

More efficient fluid power systems using variable displacement hydraulic motors  

OpenAIRE

The approach and landing phase is dimensioning for today?s aircraft fluid power systems. In this flight phase, large hydraulic consumers (flaps/slats, landing gear) have to be operated while the available hydraulic power reaches it?s minimum due to the reduced engine speed. During most of the flight the installed resources exceed the hydraulic power requirements by far; resulting in a low overall-efficiency. This paper presents an approach to increase the efficiency of today?s fluid power ...

Biedermann, Olaf; Engelhardt, Jo?rg; Geerling, Gerhard

1998-01-01

162

A Frequency Response Approach to Sliding Control Design for Hydraulic Drives  

DEFF Research Database (Denmark)

Sliding modes applied in control structures may generally provide for perfect control performance and robustness toward uncertain bounded parameters and disturbances, in the ideal case with infinite actuator bandwidth and switching frequency. However, in the context of physical systems, such performance cannot be realized due to finite actuator bandwidths and switching frequencies, which, in the case of direct application of sliding control terms, may lead to control chattering and high frequency oscillations in the system states. In order to compensate for this undesirable effect, the application of so-called boundary layers are commonly applied, guaranteeing sliding precision in some well-defined vicinity of the control target. Commonly the control target, or sliding manifold, is designed as some desired closed loop dynamics of the controlled plant, utilizing multiple states as feedback. However, when considering hydraulic cylinder drives, such full state feedback may not be available, and alternative approaches to conventional methods may be considered. This issue is addressed in this paper in regard to tracking control design for valve controlled hydraulic cylinder drives, and a design method taking its offset in linear analysis is proposed. The sliding manifold is designed based on a PI controller design, and the resulting controller provides for robustness outside a predefined boundary layer, and performance equivalent to the PI controller within the boundary layer. Results demonstrate improved tracking accuracy of the proposed controller compared the PI controller, and that performance of these controllers is equivalent within the boundary layer.

Schmidt, Lasse; Johansen, Per

2014-01-01

163

Study on step-down dynamic process of hydraulic cylinder for control rod hydraulic drive mechanism  

International Nuclear Information System (INIS)

Hydraulic cylinder (HC) is the key component of the control rod hydraulic drive mechanism(CRHDM). According to the characteristics of HC step-down process,the pressure transients in the HC during step-down process can be divided into two processes, that is, the pressure transients before step-down motion and the pressure transients during step-down motion. Theoretical dynamic pressure models of these two processes were built. And among them,the theoretical dynamic pressure model during HC step-down motion can be combined with the HC step-down kinematics model to establish a complete HC step-down dynamic model. The comparison between the theoretical results and the CRHDM single cylinder experiment shows that,under the experimental loadings, the theoretical dynamic pressure transients during the HC step-down process and the HC step-down displacements agree with the experimental results. The research results have laid the theoretical foundation for the acquisition of the key factors affecting the pressure transients of the HC during step-down process and the step motion time of the CRHDM. (authors)

164

A 6-DOF vibration isolation system for hydraulic hybrid vehicles  

Science.gov (United States)

This paper presents the results of vibration isolation analysis for the pump/motor component of hydraulic hybrid vehicles (HHVs). The HHVs are designed to combine gasoline/diesel engine and hydraulic power in order to improve the fuel efficiency and reduce the pollution. Electric hybrid technology is being applied to passenger cars with small and medium engines to improve the fuel economy. However, for heavy duty vehicles such as large SUVs, trucks, and buses, which require more power, the hydraulic hybridization is a more efficient choice. In function, the hydraulic hybrid subsystem improves the fuel efficiency of the vehicle by recovering some of the energy that is otherwise wasted in friction brakes. Since the operation of the main component of HHVs involves with rotating parts and moving fluid, noise and vibration are an issue that affects both passengers (ride comfort) as well as surrounding people (drive-by noise). This study looks into the possibility of reducing the transmitted noise and vibration from the hydraulic subsystem to the vehicle's chassis by using magnetorheological (MR) fluid mounts. To this end, the hydraulic subsystem is modeled as a six degree of freedom (6-DOF) rigid body. A 6-DOF isolation system, consisting of five mounts connected to the pump/motor at five different locations, is modeled and simulated. The mounts are designed by combining regular elastomer components with MR fluids. In the simulation, the real loading and working conditions of the hydraulic subsystem are considered and the effects of both shock and vibration are analyzed. The transmissibility of the isolation system is monitored in a wide range of frequencies. The geometry of the isolation system is considered in order to sustain the weight of the hydraulic system without affecting the design of the chassis and the effectiveness of the vibration isolating ability. The simulation results shows reduction in the transmitted vibration force for different working cycles of the regenerative system.

Nguyen, The; Elahinia, Mohammad; Olson, Walter W.; Fontaine, Paul

2006-03-01

165

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

166

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

167

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

168

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

169

Contribution on Control Strategies of Flow-On-Demand Hydraulic Circuits  

OpenAIRE

The development of an innovative flow-on-demand electrohydraulic system for mobile forestry cranes is described in the present paper. To overcome functional principle related weaknesses of conventional hydraulic-mechanical Load-Sensing systems, this work breaks up the control pressure difference related dependence of the delivered oil flow. Rather the swiveling angle of the displacement pump is calculated by summing up the single consumer oil flows corresponding to the velocity requests of th...

Scherer, Martin; Geimer, Marcus; Weiß, Bjo?rn

2013-01-01

170

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

171

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.

172

Effect of physical property of supporting media and variable hydraulic loading on hydraulic characteristics of advanced onsite wastewater treatment system.  

Science.gov (United States)

A laboratory-scale study was carried out to investigate the effects of physical properties of the supporting media and variable hydraulic shock loads on the hydraulic characteristics of an advanced onsite wastewater treatment system. The system consisted of two upflow anaerobic reactors (a septic tank and an anaerobic filter) accommodated within a single unit. The study was divided into three phases on the basis of three different supporting media (Aqwise carriers, corrugated ring and baked clay) used in the anaerobic filter. Hydraulic loadings were based on peak flow factor (PFF), varying from one to six, to simulate the actual conditions during onsite wastewater treatment. Hydraulic characteristics of the system were identified on the basis of residence time distribution analyses. The system showed a very good hydraulic efficiency, between 0.86 and 0.93, with the media of highest porosity at the hydraulic loading of PFF???4. At the higher hydraulic loading of PFF?6 also, an appreciable hydraulic efficiency of 0.74 was observed. The system also showed good chemical oxygen demand and total suspended solids removal efficiency of 80.5% and 82.3%, respectively at the higher hydraulic loading of PFF 6. Plug-flow dispersion model was found to be the most appropriate one to describe the mixing pattern of the system, with different supporting media at variable loading, during the tracer study. PMID:25428652

Sharma, Meena Kumari; Kazmi, Absar Ahmad

2015-06-01

173

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

174

Hydraulic external pre-isolator system for LIGO  

Science.gov (United States)

The hydraulic external pre-isolator (HEPI) is the first six 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 fifth science run7, successfully cutting down the disturbance seen by LLO's suspended optics in the two most prominent seismic disturbance bands, the microseism (0.1-0.3 Hz) and the anthropogenic (1-3 Hz) 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 by this success, funding for incorporating HEPI into the LIGO Hanford Observatory was approved and installation is currently underway.

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.; Evans, T.; Hanson, J.; Spjeld, O.; Macinnis, M.; Mailand, K.; Ottaway, D.; Sellers, D.; Carter, K.; Sarin, P.

2014-12-01

175

Analysis on step action of hydraulic control rod driving  

International Nuclear Information System (INIS)

The step action of the hydraulic control rod driving (HCRD) has been achieved by experiments. The author reveals the action mechanism of the HCRD, gives detail analysis of the relationship among its dynamic feature, the control rod and combined valve performance parameters, and the combined valve operation. The results indicate that the step process of the control rod is affected by output flow pulsation of the combined valve, pressure wave, and heavily damped pressure oscillation that is produced by the step cylinder movement. The performance parameters of the step cylinder limit the flow range in its stationary balanced state and also limit the capability of absorbing flow pulsation and pressure wave in its step process. The performance parameters of the combined valve decide the quantity values of stationary balance, delay balance, flowing pulsation and pressure wave. The relation of both parameters determines the step states of the control rod

176

Systems reliability analysis of mechanical and hydraulic drive systems  

International Nuclear Information System (INIS)

This article presents a new method for systems reliability analysis of mechanical and hydraulic systems. The method is based on finite element equations, which describe motion and equilibrium between internal and external loads for structures and mechanisms. This approach is different from the well-known application of the finite element method in structural reliability analysis . A detailed description shows how the finite element equations can be adapted to analyse mechanical and hydraulic systems. Quite common is the finite element description of structures of solid materials. The theory has been extended to describe the simple flow of fluids. Due to the similarity in the approach, it is possible to describe systems containing solid and fluidic components with a single set of equations. This article also covers physically non-linear behaviour of complex components, which asks for a special treatment. Therefore, two strategies to solve the systems of equations are discussed. It is shown how the theory can be implemented in software to be used by design engineers

177

Thermal hydraulic instrumentation system of the HTR-10  

International Nuclear Information System (INIS)

The 10 MW high temperature gas-cooled reactor--test module (HTR-10) has many different characteristics compared with the pressure water reactor (PWR), such as special fuel elements, core construction, helium coolant and so on. Thus, the design of thermal hydraulic instrumentation system of the HTR-10 is also different from that of a PWR. This paper describes the design criteria and system integrating method of thermal hydraulic instrumentation systems in details. The main thermal instrumentation and devices specially developed for the HTR-10 are also introduced

178

Thermal hydraulic instrumentation system of the HTR-10  

Energy Technology Data Exchange (ETDEWEB)

The 10 MW high temperature gas-cooled reactor--test module (HTR-10) has many different characteristics compared with the pressure water reactor (PWR), such as special fuel elements, core construction, helium coolant and so on. Thus, the design of thermal hydraulic instrumentation system of the HTR-10 is also different from that of a PWR. This paper describes the design criteria and system integrating method of thermal hydraulic instrumentation systems in details. The main thermal instrumentation and devices specially developed for the HTR-10 are also introduced.

Zhong Shuoping E-mail: zyleaf@public.bta.net.cn; Hu Shouyin; Zha Meisheng; Li Shengqiang

2002-10-01

179

NRC Information No. 87-56: Improper hydraulic control unit installation at BWR plants  

International Nuclear Information System (INIS)

This information notice is being provided to alert addressees to a potential problem that could affect the ability of the hydraulic control units (HCUs) to control the positioning of the control rods in the event of an earthquake. In addition, the potential for damage to the control rod drive (CRD) system withdraw lines that exists under certain conditions could result in a small-break loss-of-coolant accident in the HCU area. The CRD system controls the position of the control rods within the reactor core either to change reactor core power or to rapidly shut down the reactor (scram). The HCU is a major component of the CRD system that incorporates all the hydraulic, electrical, and pneumatic equipment necessary to move one CRD mechanism during normal or scram operations. This equipment, which includes the accumulators, CRD insert lines, CRD withdraw lines, and scram valves, is supported by the HCU frames. If a sufficiently large number of HCU frame bolts are missing or loose, a Safe Shutdown Earthquake (SSE) could result in damage affecting the ability of the CRD system to control the positioning of the control rods. In addition, damage to a CRD withdraw line could result in a small-break loss-of-coolant accident in the area of the HCUs

180

Understanding the Space Shuttle Main Engine Hydraulic Actuation System and Reviewing Its Evolution  

Science.gov (United States)

The complex engine start and thrust control requirements of the Space Shuttle Main Engine (SSME) require unique valve, actuator and control system hardware. The Hydraulic Actuation System (HAS) was designed, developed, and now operates to meet tight engine control requirement limits to assure safe, reliable and correct engine thrust at all times. The actuator is designed to be fail safe and fail operate in the areas where redundancy is important. The HAS has an additional pneumatic operating capability that insures a safe sequential closure of all actuators and propellant valves in the event of the loss of hydraulic system pressure or loss of electrical closed loop control of the actuator. The objective of this paper is to provide a complete description of the actuator s internal operating system, along with its interaction with all SSME system interfaces. Additionally the paper addresses the challenges, problems identified, and corrected, and lessons learned, during the course of the almost 35 years of engine operation.

McWade, Robert J.; Minor, Robert B.; McNutt, Leslie M.

2010-01-01

181

Primary system thermal hydraulics of future FBRS  

International Nuclear Information System (INIS)

As a follow-up to PFBR (Indian Prototype Fast Breeder Reactor), many FBRs of 500 MWe capacity are planned. The focus of these future FBRs is improved economy and enhanced safety. They are envisaged to have a twin-unit concept. Design and construction experiences gained from PFBR project have motivated the centre to achieve an optimized design for future FBRs with significant design changes for many critical components. Some of the design changes include, (i) provision of four primary pipes per primary sodium pump, (ii) inner vessel with single torus lower part, (iii) Roof Slab (RS) with a dome shape supported on Reactor Vault (RV), (iv) machined thick plate rotating plugs, (v) reduced main vessel diameter with narrow-gap cooling baffles and (vi) safety vessel integrated with RV. This paper covers thermal hydraulic design validation of the chosen options with respect to hot and cold pool thermal hydraulics, flow requirement for main vessel cooling, inner vessel temperature distribution, safety analysis of primary pipe rupture event, cold pool transient thermal loads and thermal management of top shield and reactor vault. (author)

182

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

183

Adaptive Control of a Hydraulic Crane using On-Line Identification  

OpenAIRE

In this paper we present an approach to adaptive control of hydraulic actuators with flexible mechanical loads. The approach is based on recursive identification of low order models of the dynamics from valve input to actuator position and effective load pressure respectively. The model parameters are used to compute a regulator that gives a well damped system with good servo properties. The identification is carried out on-line in closed loop with no other signals than those present in norma...

Krus, Petter; Gunnarsson, Svante

1993-01-01

184

Full equations utilities (FEQUTL) model for the approximation of hydraulic characteristics of open channels and control structures during unsteady flow  

Science.gov (United States)

The Full EQuations UTiLities (FEQUTL) model is a computer program for computation of tables that list the hydraulic characteristics of open channels and control structures as a function of upstream and downstream depths; these tables facilitate the simulation of unsteady flow in a stream system with the Full Equations (FEQ) model. Simulation of unsteady flow requires many iterations for each time period computed. Thus, computation of hydraulic characteristics during the simulations is impractical, and preparation of function tables and application of table look-up procedures facilitates simulation of unsteady flow. Three general types of function tables are computed: one-dimensional tables that relate hydraulic characteristics to upstream flow depth, two-dimensional tables that relate flow through control structures to upstream and downstream flow depth, and three-dimensional tables that relate flow through gated structures to upstream and downstream flow depth and gate setting. For open-channel reaches, six types of one-dimensional function tables contain different combinations of the top width of flow, area, first moment of area with respect to the water surface, conveyance, flux coefficients, and correction coefficients for channel curvilinearity. For hydraulic control structures, one type of one-dimensional function table contains relations between flow and upstream depth, and two types of two-dimensional function tables contain relations among flow and upstream and downstream flow depths. For hydraulic control structures with gates, a three-dimensional function table lists the system of two-dimensional tables that contain the relations among flow and upstream and downstream flow depths that correspond to different gate openings. Hydraulic control structures for which function tables containing flow relations are prepared in FEQUTL include expansions, contractions, bridges, culverts, embankments, weirs, closed conduits (circular, rectangular, and pipe-arch shapes), dam failures, floodways, and underflow gates (sluice and tainter gates). The theory for computation of the hydraulic characteristics is presented for open channels and for each hydraulic control structure. For the hydraulic control structures, the theory is developed from the results of experimental tests of flow through the structure for different upstream and downstream flow depths. These tests were done to describe flow hydraulics for a single, steady-flow design condition and, thus, do not provide complete information on flow transitions (for example, between free- and submerged-weir flow) that may result in simulation of unsteady flow. Therefore, new procedures are developed to approximate the hydraulics of flow transitions for culverts, embankments, weirs, and underflow gates.

Franz, Delbert D.; Melching, Charles S.

1997-01-01

185

Recurrent-neural-network-based identification of a cascade hydraulic actuator for closed-loop automotive power transmission control  

International Nuclear Information System (INIS)

By virtue of its ease of operation compared with its conventional manual counterpart, automatic transmissions are commonly used as automotive power transmission control system in today's passenger cars. In accordance with this trend, research efforts on closed-loop automatic transmission controls have been extensively carried out to improve ride quality and fuel economy. State-of-the-art power transmission control algorithms may have limitations in performance because they rely on the steady-state characteristics of the hydraulic actuator rather than fully exploit its dynamic characteristics. Since the ultimate viability of closed-loop power transmission control is dominated by precise pressure control at the level of hydraulic actuator, closed-loop control can potentially attain superior efficacy in case the hydraulic actuator can be easily incorporated into model-based observer/controller design. In this paper, we propose to use a recurrent neural network (RNN) to establish a nonlinear empirical model of a cascade hydraulic actuator in a passenger car automatic transmission, which has potential to be easily incorporated in designing observers and controllers. Experimental analysis is performed to grasp key system characteristics, based on which a nonlinear system identification procedure is carried out. Extensive experimental validation of the established model suggests that it has superb one-step-ahead prediction capability over appropriate frequency range, making over appropriate frequency range, making it an attractive approach for model-based observer/controller design applications in automotive systems

186

The hydraulic lifting system for the main magnets of CYCIAE-30 cyclotron  

CERN Document Server

The oil-line structure, control system and their working principles of the hydraulic lifting system for the main magnets of CYCIAE-30 cyclotron are introduced. The six years practice proves that the specification of the system matches the requirements: the oil cylinder maximum stroke of 850 mm, the eight slot positioning dowels repositioning accuracy of +-0.01 mm, the two oil cylinders moving in step accuracy of 5-10 mm. The system is safe, reliable and easy to be operated

Zhao Zhen Lu; Chen Rong Fan; Chu Cheng Jie

2002-01-01

187

Estimation of hydraulic conductivity in an alluvial system using temperatures.  

Science.gov (United States)

Well water temperatures are often collected simultaneously with water levels; however, temperature data are generally considered only as a water quality parameter and are not utilized as an environmental tracer. In this paper, water levels and seasonal temperatures are used to estimate hydraulic conductivities in a stream-aquifer system. To demonstrate this method, temperatures and water levels are analyzed from six observation wells along an example study site, the Russian River in Sonoma County, California. The range in seasonal ground water temperatures in these wells varied from channel. Hydraulic conductivities are estimated by matching simulated ground water temperatures to the observed ground water temperatures. An anisotropy of 5 (horizontal to vertical hydraulic conductivity) generally gives the best fit to the observed temperatures. Estimated conductivities vary over an order of magnitude in the six locations analyzed. In some locations, a change in the observed temperature profile occurred during the study, most likely due to deposition of fine-grained sediment and organic matter plugging the streambed. A reasonable fit to this change in the temperature profile is obtained by decreasing the hydraulic conductivity in the simulations. This study demonstrates that seasonal ground water temperatures monitored in observation wells provide an effective means of estimating hydraulic conductivities in alluvial aquifers. PMID:15584302

Su, Grace W; Jasperse, James; Seymour, Donald; Constantz, Jim

2004-01-01

188

Hydraulic drive with a control rod for nuclear reactors  

International Nuclear Information System (INIS)

For a control rod with a piston part, which consists of alternate projections and grooves on a piston rod, and with a cylinder, which also has alternate projections and grooves, and which surrounds the piston rod, the cylinder has at least two groups of projections and grooves. There is a space between the two groups, in which the diameter of the cylinder is greater than the diameter of the projections. Therefore, the piston rod is provided with projections and grooves over at least the length of the space, is surrounded by one or other group and is kept stationary or moved by hydraulic liquid. The piston rod is made as a tube surrounding an absorber material (B4C, Hf, steel), particularly for a heavy water-cooled BWR. (orig./HP)

189

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

190

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

191

Load control system. [for space shuttle external tank ground tests  

Science.gov (United States)

The load control system developed for the shuttle external structural tests is described. The system consists of a load programming/display module, and a load control module along with the following hydraulic system components: servo valves, dump valves, hydraulic system components, and servo valve manifold blocks. One load programming/display subsystem can support multiple load control subsystem modules.

Grosse, J. C.

1977-01-01

192

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

193

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

194

The Integration of an Electro-Hydraulic Manipulator Arm into a Self-Contained Mobile Delivery System  

Energy Technology Data Exchange (ETDEWEB)

The Portable Articulated Arm Deployment System (PAADS) is a remotely controlled vehicle for delivering a tele-operated electro-hydraulic manipulator arm to a field-deployable location. The self-contained system includes a boom vehicle with long reach capability, an electro-hydraulic manipulator arm, closed circuit television (CCTV) systems, and onboard tools. On board power systems consist of a self-contained, propane-fired 8-KW generator and an air compressor for pneumatic tools. The generator provides the power to run the air compressor as well as power to operate the 110-VAC auxiliary lighting system for the video cameras. The separate control console can be located up to 500 ft from the vehicle. PAADS is a fully integrated system, containing all equipment required to perform complex field operations. Hydraulic integration of the manipulator arm into the vehicle hydraulic drive system was necessary to eliminate the tether management of hoses, which extended vehicle operating range, minimized hydraulic pressure losses, and provided the opportunity to go to a radio frequency (RF) control system in the future, thereby eliminating the control cable. This paper presents the key decision points during system development. Emphasis is placed on ease of operator control and not on an intelligent machine approach. In addition, emphasis is placed on the philosophy of remote operation based on sound principles of integration.

M. Borland; S. M. Berry

1999-04-01

195

The Integration of an Electro-hydraulic Manipulator Arm into a Self-contained Mobile Delivery System  

Energy Technology Data Exchange (ETDEWEB)

The Portable Articulated Arm Deployment System (PAADS) is a remotely controlled vehicle for delivering a tele-operated electro-hydraulic manipulator arm to a field deployable location. The self-contained system includes a boom vehicle with long reach capability, an electro-hydraulic manipulator arm, closed circuit television (CCTV) systems, and onboard tools. On board power systems consist of a self contained, propane fired 8 KW generator and an air compressor for pneumatic tools. The generator provides the power to run the air compressor as well as provide power to operate the 110 VAC auxiliary lighting system for the video cameras. The separate control console can be located up to 500 ft from the vehicle. PAADS is a fully integrated system, containing all equipment required to perform complex field operations. Hydraulic integration of the manipulator arm into the vehicle hydraulic drive system was necessary to eliminate the tether management of hoses, which extended vehicle operating range, minimized hydraulic pressure losses, and provided the opportunity to go to a radio frequency (RF) control system in the future, thereby eliminating the control cable. This paper presents the key decision points during system development. Emphasis is placed on ease of operator control and not on an intelligent machine approach. In addition, emphasis is placed on the philosophy of remote operation based on sound principles on integration.

Borland, Mark Wilson; Berry, Stephen Michael

1999-04-01

196

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)

197

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

198

14 CFR 23.1435 - Hydraulic systems.  

Science.gov (United States)

...for such changes to occur. (4) The minimum design burst pressure must be 2.5 times the operating pressure. (b) Tests. Each system must be substantiated by proof pressure tests. When proof tested, no part of any system may...

2010-01-01

199

Tests of a system for feeding and withdrawing SHC hydraulic props with emulsion recovery  

Energy Technology Data Exchange (ETDEWEB)

Design and performance tests are evaluated for a system developed by the GLINIK Plant for Drilling and Mining Equipment for feeding and withdrawing the SHC hydraulic props with emulsion recovery. The system consists of a number of connector pipes, valves and joints. Its design is shown in 3 schemes. The system was equipped with remote control for support withdrawal under conditions of rock falls. The equipment was tested under laboratory conditions and later under operational conditions in 4 coal mines in Upper Silesia. The SHC hydraulic props with the GIG and SHZ valve systems were withdrawn. The tests showed that the system was reliable and safe. Under conditions of efficient valves on the SHC props, the equipment developed by the GLINIK plant guaranteed recovery of about 80% emulsion. Occupational safety during support withdrawal improved. Due to increased labor consumption the system was not recommended for commercial production. Further tests of the system aimed at its commercial production are recommended.

Domasik, J.; Moskal, J.

1986-01-01

200

Mathematical modelling of hydraulic conditions of balancing and control of heating, cooling and dehumidification subsystem in ventilation and air conditioning systems  

Directory of Open Access Journals (Sweden)

Full Text Available The article is the second part of the one published in the Vol. 1, 2011. The aim of this research is processes modelling and investigation of quantity parameters influence on heating and cooling subsystem of VAC systems when balancing that subsystem by various balanced valves and when controlling it by three-way valve. The basic characteristic received and analyzed in model, is balancing-adjusting characteristic (schedule of mixture in knot depending on a combination of many factors: binding, crosspieces, an arrangement of corresponding valves, pressures and other parameters. For reception of the balancing-adjusting characteristic of subsystem in different operating modes its mathematical model was created, methods of processing and generalization of the data were offered. After that calculations in different modes of use of the crosspieces were done, allowed to define all regime parameters at the set positions of balancing and regulating valves, parity of pressures in a network and a pump, design of armature and entry conditions.

A. G. Sotnikov

2011-03-01

201

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

International Nuclear Information System (INIS)

The present research aims at the development of the thermal hydraulic verification test technology for the reactor safety system of the conventional and advanced nuclear power plant and the development of the advanced thermal hydraulic measuring techniques. (Author)

202

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

203

1B hydraulic system: Sydney Coalfield, Glace Bay, Nova Scotia  

Energy Technology Data Exchange (ETDEWEB)

The paper uses diagrams and maps to show the 1B hydraulic system of the Sydney coal field and the sequence of coal seams (Hub, Harbour, Phalen, and Emery seams) at Donkin Mine. The water elevation (feet below sea level) in the 1B hydraulic system over the period March 1986 to May 2005 is shown on a graph. Data on pH, sulphates, and iron and other metallic contaminants at the No. 5 colliery well field are tabulated for October 2002 and January 2003. Graphs show the half-life projections for the decay of iron 1A water over the period 2003 to 2058 and the concentration of iron predicted for 1A water and other Glace Bay outfalls to 2117. 44 figs., 1 tab.

Forgeron, S. [Conestoga-Rovers & Associates, Fredericton, NB (Canada)

2006-10-15

204

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

205

THERMAL HYDRAULIC ANALYSIS OF A GAS TEST LOOP SYSTEM  

Energy Technology Data Exchange (ETDEWEB)

This paper discusses thermal hydraulic calculations for a Gas Test Loop (GTL) system designed to provide a high intensity fast-flux irradiation environment for testing fuels and materials for advanced concept nuclear reactors. To assess the performance of candidate reactor fuels, these fuels must be irradiated under actual fast reactor flux conditions and operating environments, preferably in an existing irradiation facility [1]. Potential users of the GTL include the Generation IV Reactor Program, the Advanced Fuel Cycle Initiative and Space Nuclear Programs.

Donna Post Guillen; James E. Fisher

2005-11-01

206

Logic Threshold Based Energy Control Strategy for Parallel Hydraulic Hybrid Vehicles  

Directory of Open Access Journals (Sweden)

Full Text Available 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 vehicle dynamic performance is developed using the Simulink in MATLAB. The multi-objective Genetic Algorithm (GA optimization method is employed to get the optimal working modes, the best energy distribution in different drive cycles and the optimal parameters of the control strategy. In this optimization, maximum fuel economy is the objective and the difference of engine optimal torque and active pressure torque and the pressure limit are the variables of the GA optimization. The simulation results show that the fuel economy of the PHHV can be improved and in addition, the dynamic performance of the vehicle can be enhanced with the proposed energy control strategy.

Liu-Tao

2013-08-01

207

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

208

Design of a hydraulic power take-off system for the wave energy device with an inverse pendulum  

Science.gov (United States)

This paper describes a dual-stroke acting hydraulic power take-off (PTO) system employed in the wave energy converter (WEC) with an inverse pendulum. The hydraulic PTO converts slow irregular reciprocating wave motions to relatively smooth, fast rotation of an electrical generator. The design of the hydraulic PTO system and its control are critical to maximize the generated power. A time domain simulation study and the laboratory experiment of the full-scale beach test are presented. The results of the simulation and laboratory experiments including their comparison at full-scale are also presented, which have validated the rationality of the design and the reliability of some key components of the prototype of the WEC with an inverse pendulum with the dual-stroke acting hydraulic PTO system.

Zhang, Da-hai; Li, Wei; Zhao, Hai-tao; Bao, Jing-wei; Lin, Yong-gang

2014-04-01

209

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

International Nuclear Information System (INIS)

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

210

Super Twisting Second Order Sliding Mode Control for Position Tracking Control of Hydraulic Drives  

DEFF Research Database (Denmark)

In this paper a control strategy based on second order sliding modes, generally applicable for position tracking control of electro-hydraulic valve-cylinder drives (VCD), is proposed. The main target is to overcome problems with linear controllers deteriorating performance due to the strong nonlinearities characterizing VCD's. The proposed controller requires pressure-, valve- and piston position measurements, and is based on the so-called super twisting algorithm and compensation of controlgain nonlinearities. Simulation results demonstrate strong robustness when subjected to large perturbations in coulomb friction.

Schmidt, Lasse; Andersen, Torben Ole

2013-01-01

211

Selection of the 700 MWe PHWR pressuriser level control program through thermal hydraulic transient studies  

International Nuclear Information System (INIS)

Full text: Conventionally the Pressuriser capacity, heater rating and the liquid level program are the important parameters to be optimized for reliable and trouble free operation of a water cooled nuclear power plants like Pressurised Heavy Water Reactor (PHWR). All these parameters are affected by the volume of the Primary Heat Transport (PHT) system and the corresponding swell/shrinkages anticipated. The magnitude of the swell/shrinkages depend on the rate of change of the PHT system fluid and structural temperatures for various transients. Based on these values the design of the PHT system pressure controller can be optimized. The 700 MWe PHWR PHT system design allows limited boiling towards the end of the coolant channel. The swell/shrinkages due to phase change are of larger magnitude but the pressure variation may be dampened during the two-phase PHT fluid condition with higher compressibility. The transition from single phase to two phase PHT system also needs to be analyzed for all the operational aspects such as the reactivity variation, process dynamics and the performance of the controllers. The secondary system behaviors also affect the PHT system volumetric changes due to thermal coupling. The performance of the selected Steam Generator Pressure Control Program (SGPC) also dictates the design of the PHT system pressure controller. The SGPC controller setting also has a considerable bearing on the performance of the PHT system pressure controller. Constanhe PHT system pressure controller. Constant Boiler Pressure Program (CBPP) has been adopted design for this reactor. This program leads to higher values of shrinkages due to higher temperature difference between the PHT and the SGs. The design basis transient must account for the maximum credible swell/shrinkages anticipated/envisaged. The turbine trip transient and the reactor trip transient can form the basis with appropriate initial condition assumptions. The PHT system Instrumented Relief Valves sizing transient also can considered for the design basis, though this is not an operational event. This paper describes the computer simulation model that has been developed for the upcoming 700 MWe PHWR using internationally renowned, best estimate RELAP5/MOD3.2 code for the thermal hydraulic behavior. The output from these simulation studies is being utilized for performance verification of the PHT system pressure controller and the Pressuriser level control program. Earlier such studies have been performed for the 540 MWe PHWR power plants. The 700 MWe PHWR SGs differs from the earlier SGs in many of the design details. The implication of these details on the thermal hydraulic behavior and the corresponding impact on the design will be discussed. (author)

212

An adaptive fuzzy dead-zone compensation scheme and its application to electro-hydraulic systems  

Scientific Electronic Library Online (English)

Full Text Available The dead-zone is one of the most common hard nonlinearities in industrial actuators and its presence may drastically compromise control systems stability and performance. Due to the possibility to express specialist knowledge in an algorithmic manner, fuzzy logic has been largely employed in the las [...] t decades to both control and identification of uncertain dynamical systems. In spite of the simplicity of this heuristic approach, in some situations a more rigorous mathematical treatment of the problem is required. In this work, an adaptive fuzzy controller is proposed for nonlinear systems subject to dead-zone input. The boundedness of all closed-loop signals and the convergence properties of the tracking error are proven using Lyapunov stability theory and Barbalat's lemma. An application of this adaptive fuzzy scheme to an electro-hydraulic servo-system is introduced to illustrate the controller design method. Numerical results are also presented in order to demonstrate the control system performance.

Wallace M., Bessa; Max S., Dutra; Edwin, Kreuzer.

2010-03-01

213

Role of system characteristics in evolution of pump hydraulic design  

International Nuclear Information System (INIS)

Primary heat transport (PHT) main circuit provides the means for transferring the heat produced in the fuel by circulating heavy water in the main circuit loop by primary coolant pumps (PCPs). The procurement specification of PCPs for 500 MWe pressurised heavy water reactor (PHWR) was prepared based upon the first order hydraulic analysis of the primary heat transport system and accordingly duty point was fixed. With this specification the manufacturer carried out model testing to arrive at optimum size of the impeller followed by determination of pump characteristics curves using full scale impeller during type testing. The duty point thus obtained was higher than specified necessitating the trimming of impeller. However, in order to make use of available higher duty point from system considerations, the duty point was redefined for production of subsequent pumps within specified tolerances governed by manufacturing limitations. PHT main system sizing (piping and feeders) was carried out based upon pump (delivering maximum flow) characteristics curve. Pressure profiles of PHT system at various operating modes were drawn and corresponding power drawn by motor was calculated. The interfacing of reactor coolant main system with hydraulic characteristics of PCP plays a significant role in establishing the requisite capability and capacity of PHT system in performing its intended functions. Therefore the paper traces the evolution of design parameters for PCP and subseque of design parameters for PCP and subsequent generation of pressure profiles commensurate with the changes made in power profile including their impact on feeder sizing. The paper also highlights the scope of interaction between process designer and pump manufacturer in formulating a mutually acceptable and efficient hydraulic performance for PCP. (author). 3 refs., 8 figs., 3 tabs

214

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)

215

Thermal-hydraulics of lead bismuth for accelerator driven systems  

Energy Technology Data Exchange (ETDEWEB)

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 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)

Thomas Schulenberg; Xu Cheng; Robert Stieglitz [Institute for Nuclear and Energy Technologies, Forschungszentrum Karlsruhe, P.O. Box 3640, 76021 Karlsruhe (Germany)

2005-07-01

216

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

217

Hydraulic transient analysis in circulating water pump system  

International Nuclear Information System (INIS)

The present paper has dealt with the various phenomena associated with the hydraulic transient operation of pump system following the interruption of flow from its steady state with a special reference on the classical sloshing phenomena. The phenomena often encountered in the piping network following the separation of liquid column and the formation of cavity inside the pipe results in reverse transient pressure built up upon subsequent rejoining of separated liquid columns. A computer programme has been developed to predict the transient behaviour of circulating water (CW) pump system considering the various hydrodynamic phenomena involved in the process. (author). 2 refs., 12 figs

218

Project calculation of the steering mechanism hydraulic servo control in motor vehicles  

Directory of Open Access Journals (Sweden)

Full Text Available Hydraulic servo controls are designed to facilitate rotation in place without providing increased ppower to steering wheels. In the initial design phase, the dimensions required for control systems are usually obtained through the calculation of their load when wheels rotate in place, where the torque is calculated empirically. The starting point in the project calculation is thus to determine the hydraulic power steering torque torsional resistance which is then used to determine the maximum value of force i.e. the torque on the stering wheel. The calculation of the control system servo control consists of determining the basic parameters, the required pump capacity, the main dimensions of the hub and the  pipeline and the conditions for the stability of the system control mechanism. Introduction The aim of the calculation of the steering control system is to determine the basic parameters of its components which ensure the fulfilment of requirements of the control system. Calculations are performed in several stages with a simultaneous  detailed constructive analysis of the control system leading to the best variant. At each stage, design and control calculations of the hydraulic servo of the steering mechanism are performed. The design allows the computation to complete the selection of basic dimensions of the amplifer elements, starting from the approved scheme and the basic building loads of approximate values. Calculations control is carried out to clarify the structural solution and to obtain the output characteristics of the control amplifier which are applied in the  estimation of  potential properties of the structure. Project calculation Baseline data must be sufficiently reliable, ie. must correspond to the construction characteristics of the vehicle design and the control system as well as to service conditions..A proper deterimination of the torque calculation of torsional resistance in wheels is of utmost importance. Moment of resistance to wheel rotation in place The magnitude of the torque required to rotate drive wheels in place, is affected by: 1 load on wheels; 2 coefficient of friction of the tire surface; 3 dimensions and shape of the tire footprint on the surface, as deterimined by the pressure in the tire and its construction; 4 lateral stiffness of the tire; 5 turning radius of drive wheels; 6 angles of inclination of the pin; 7 moment of friction in pins and steering gear mechanism. To achieve the proper torque values of torsional resistance in drive wheels, it is necessary to take into account all these influential factors, as this provides a lower load on the elements in the control system while enabling easier control and reducing the moment of force on the steering wheel. Moment of resistance to rotating drive wheels in place according to Mitin Mitin obtained the coefficient  only for one tire so the use of this formula is practically impossible. Moment of resistance to rotating drive wheels in place according to Taborek Moment of resistance to rotating drive wheels in place according to Lisov This formula takes into account the radius of the tire, but does not take into account the pressure and elastic characteristics of tires. Moment of resistance ito rotating drive wheels in place by Litvinov For the calculation by this formula, it is necessary to know the dependence of the tire footprint surface and the load on it. Moment of resistance to rotating drive wheels in place by Gough Experimental studies have shown that this term is very acceptable. Dimensions of the executive hydraulic cylinder The control amplifier must provide that the wheels rotate in place when the force of the driver on the steering wheel is not above 160 – 200 N in a complete range of the rotation angles from   for the inner wheel to for the outer wheel. Reactive and centering elements of the hydraulic servo control The control system without a hydraulic servo control must have one very important characteristic which is to develop the ability of the driver to feel the road configuration, esp

Zoran ?ukan Majki?

2013-10-01

219

Hydrocone Crusher : A new fast robust design of the hydraulic system  

OpenAIRE

This master thesis has been conducted at Sandvik Svedala. The thesis is the first step towards a new construction of a hydraulic system for a Hydrocone crusher. First we studied how contaminations entered the system of today. Then the work began with designing several concepts to control the crusher. These basic concepts were presented to Sandvik and the one was chosen for further development was fine tuned and a system was built. This system was tested at a test rig to verify that the basic ...

Vestman, Johan; Sjo?berg, Patrik

2008-01-01

220

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)

221

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

222

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

223

Control system for NPP powerfull turbines  

International Nuclear Information System (INIS)

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

224

Hydraulic support stability control of fully mechanized top coal caving face with steep coal seams based on instable critical angle  

Energy Technology Data Exchange (ETDEWEB)

The support instable mode of sliding, tripping, and so on was analysed. It was assumed that the key point of support stability control of fully mechanized coal caving face with steep coal seams was to maintain the seam true angle at less than the hydraulic support instability critical angle. Through the layout of oblique face, the improvement of support setting load, the control of mining height and nonskid platform, the group support system of end face, the advance optimization of conveyor and support, and the other control technical measures, the true angle of the seam is reduced and the instable critical angle of the support is increased. The hydraulic support stability of fully mechanized coal caving face with steep coal seams is effectively controlled. 6 refs., 2 figs., 2 tabs.

Tu, Shi-hao; Yuan, Yong; Li, Nai-liang; Dou, Feng-jin; Wang, Fang-tian [China University of Mining & Technology, Xuzhou (China). State Key Laboratory of Coal Resource and Mine Safety, School of Mining Engineering

2008-09-15

225

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.

226

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.

227

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

228

Rotational speed control for hydraulic motors using sliding-mode control. 2. Rotational speed control test using an inertial load unit; Sliding mode seigyo wo mochiita yuatsu motor no kaitensu seigyo. 2. Kansei fuka sochi wo mochiita kaitensu seigyo shiken  

Energy Technology Data Exchange (ETDEWEB)

A discrete time sliding mode control theory is applied to a speed control system of heavy inertial load using an electrical hydraulic servo motor. The design models of controlled systems, including a solenoid relief valve and servo motor, are constructed using the open-loop test results, for robust stability by a simple algorithm. This paper reports results of the tests for effectiveness of the controlled systems and robust performance against disturbances. (translated by NEDO)

Tada, K.; Sato, K. [Yokohama National University, Yokohama (Japan)

1999-01-15

229

Development of a hydraulic control mechanism for cyclic pitch marine current turbines  

Energy Technology Data Exchange (ETDEWEB)

Tidal power generation by means of marine current farms is potentially a large renewable energy resource which could be harnessed in many coastal waters. Its availability is highly predictable in time, and the technology promises high energy conversion efficiency along with a relatively low impact on sea life due to its relatively small disturbance of natural tidal flows. A series of devices have so far been proposed and developed for the extraction and conversion of kinetic energy present in tidal flows into useful electrical power [1]. Designs include horizontal axis turbines, vertical axis turbines, and devices with oscillating lift surfaces. Up to date no technology has firmly established itself. This paper describes a novel hydraulic control mechanism designed for vertical-axis marine current turbines of the straight-bladed Darrieus type. It has been found to significantly improve turbine efficiency over conventional Darrieus turbines when operated at low blade tip-speed to tidal-flow-velocity ratios (TSR) and to give the turbine the ability to self-start reliably. The control mechanism enforces a cyclic pivoting motion on the turbine blades as they move around their circular flight-path. The movement of the pitch control is of sinusoidal shape and is continuously variable in amplitude. The blade actuation is powered by the turbine's own rotation and is implemented using a swash-plate mechanism in conjunction with a hydraulic circuit for every blade. For surface piercing turbines, this control mechanism may be remotely positioned in a dry nacelle above sea level. If the appropriate design is applied, this can offer access to the cyclic pitch control mechanism, gearbox and generator, even when the turbine is operational, promising lower maintenance and operating costs compared with submerged systems. (author)

Schoenborn, Alessandro; Chantzidakis, Matthew [University College London, London (United Kingdom). Department of Mechanical Engineering

2007-04-15

230

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

231

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

232

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

233

Optimal hydraulic design of new-type shaft tubular pumping system  

Science.gov (United States)

Based on the characteristics of large flow rate, low-head, short annual operation time and high reliability of city flood-control pumping stations, a new-type shaft tubular pumping system featuring shaft suction box, siphon-type discharge passage with vacuum breaker as cutoff device was put forward, which possesses such advantages as simpler structure, reliable cutoff and higher energy performance. According to the design parameters of a city flood control pumping station, a numerical computation model was set up including shaft-type suction box, siphon-type discharge passage, pump impeller and guide vanes. By using commercial CFD software Fluent, RNG ?-epsilon turbulence model was adopted to close the three-dimensional time-averaged incompressible N-S equations. After completing optimal hydraulic design of shaft-type suction box, and keeping the parameters of total length, maximum width and outlet section unchanged, siphon-type discharge passages of three hump locations and three hump heights were designed and numerical analysis on the 9 hydraulic design schemes of pumping system were proceeded. The computational results show that the changing of hump locations and hump heights directly affects the internal flow patterns of discharge passages and hydraulic performances of the system, and when hump is located 3.66D from the inlet section and hump height is about 0.65D (D is the diameter of pump impeller), the new-type shaft tubular pumping system achieves better energy performances. A pumping system model test of the optimal designed scheme was carried out. The result shows that the highest pumping system efficiency reaches 75.96%, and when at design head of 1.15m the flow rate and system efficiency were 0.304m3/s and 63.10%, respectively. Thus, the validity of optimal design method was verified by the model test, and a solid foundation was laid for the application and extension of the new-type shaft tubular pumping system.

Zhu, H. G.; Zhang, R. T.; Zhou, J. R.

2012-11-01

234

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

235

A method for dynamic system characterization using hydraulic series resistance.  

Science.gov (United States)

The pressure required to drive flow through a microfluidic device is an important characteristic of that device. We present a method to measure the flow rate through microfluidic components and systems, including micropumps and microvalves. The measurement platform is composed of two pressure sensors and a glass tube, which provides series resistance. The principle of the measurement is the fluid dynamical equivalent of Ohm's law, which defines the relationship between current, resistance, and voltage that are analogues to flow rate, hydraulic resistance, and pressure drop, respectively. Once the series resistance is known, it is possible to compute the flow rate through a device based on pressure alone. In addition, the dynamic system characteristics of the device-resistance and capacitance-can be computed. The benefits of this method are its simple configuration, capability of measuring flow rate accurately from the more easily measured pressure, and the ability to predict the dynamic response of microfluidic devices. PMID:16652179

Kim, Dongshin; Chesler, Naomi C; Beebe, David J

2006-05-01

236

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

237

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

238

Hydraulic Performance of a Downstream Controlled Irrigation Canal equipped with Difeerent Offtake Types  

OpenAIRE

Regarding canal management modernization, water savings and water delivery quality, the study presents two automatic canal control approaches of the PI (Proportional and Integral) type: the distant and the local downstream control modes. The two PI controllers are defined, tuned and tested using a hydraulic unsteady flow simulation model, particularly suitable for canal control studies. The PI control parameters are tuned using optimization tools. The simulations are done for a Portuguese pro...

Rijo, Manuel; Arranja, Carina

2005-01-01

239

Coupled thermal-hydraulic-chemical modelling of enhanced geothermal systems  

Science.gov (United States)

The study investigates thermal-, hydraulic- and chemically coupled processes of enhanced geothermal systems (EGS). On the basis of the two existing numerical codes, the finite element program FRACTURE and the geochemical module of CHEMTOUGH, FRACHEM was developed, to simulate coupled thermal-hydraulic-chemical (THC) processes, accounting for the Soultz specific conditions such as the high salinity of the reservoir fluid and the high temperatures. The finite element part calculates the thermal and hydraulic field and the geochemical module the chemical processes. According to the characteristics of the Soultz EGS reservoir, the geochemical module was modified. (i) The Debye-Huckel approach was replaced by the Pitzer formalism. (ii) New kinetic laws for calcite, dolomite, quartz and pyrite were implemented. (iii) The porosity-permeability relation was replaced by a new relation for fractured rock. (iv) The possibility of re-injecting the produced fluid was implemented. The sequential non-iterative approach (SNIA) was used to couple transport and reactions. Sensitivity analyses proved the proper functionality of FRACHEM, but highlighted the sensitivity of the SNIA approach to time steps. To quantify the FRACHEM results, a comparative simulation with the code SHEMAT was conducted, which validated FRACHEM. Coupled THC processes in a fractured zone in the Soultz reservoir at 3500 m (T0= 165 °C), which occur as a result of the injection of fluid (Tinj= 65 °C) at one end of the zone and the production at the other end, were modelled for 2 yr. Calcite is the most reactive mineral and therefore the porosity and permeability evolution results from the calcite reactions: near the injection point, porosity and permeability increase and near the production well they decrease. After 2 yr, the system seems to be very close to steady-state. Therefore, mineral dissolution and precipitation during the circulation of the fluid in the reservoir do not represent a limiting factor on the EGS reservoir (at 3500 m depth) performance at the Soultz site. Finally, the numerical transmissivity was compared to the transmissivity of the 1997 circulation test. The fact that the transmissivity decreases during the circulation test, when thermomechanical effects are factored out, points to geochemical processes in the reservoir such as the precipitation of calcite. These findings highlight the importance of THC coupled EGS reservoir models. The integration of geochemical considerations is therefore indispensable for integrated simulations of EGS systems and predictions of its performance.

Bächler, D.; Kohl, T.

2005-05-01

240

Scaling in nuclear reactor system thermal-hydraulics  

International Nuclear Information System (INIS)

Scaling is a reference 'key-word' in engineering and in physics. The relevance of scaling in the water cooled nuclear reactor technology constitutes the motivation for the present paper. The origin of the scaling-issue, i.e. the impossibility to get access to measured data in case of accident in nuclear reactors, is discussed at first. The so-called 'scaling-controversy' constitutes an outcome. Then, a critical survey (or 'scaling state-of-art';) is given of the attempts and of the approaches to provide a solution to the scaling-issue in the area of Nuclear Reactor System Thermal-Hydraulics (NRSTH): dimensionless design factors for Integral Test Facilities (ITF) are distinguished from scaling factors. The last part of the paper has a two-fold nature: (a) classifying the information about achievements in the area of thermal-hydraulics which are relevant to scaling: the concepts of 'scaling-pyramid' and the related 'scaling bridges' are introduced; (b) establishing a logical path across the scaling achievements (represented as a 'scaling puzzle'). In this context, the 'roadmap for scaling' is proposed: the objective is addressing the scaling issue when demonstrating the applicability of system codes in the licensing process of nuclear power plants. The code itself is referred hereafter as the 'key-to-scaling'. The database from the operation of properly scaled ITF and the availability of qualified system codes are identified as main achievements in NRSTH connected with main achievements in NRSTH connected with scaling. The 'roadmap to scaling' constitutes a unified approach to scaling which aims at solving the 'scaling puzzle' created by researches performed during a half-a-century period.

241

Non-linear seismic analysis in NSSS system for SG hydraulic snubber elimination  

International Nuclear Information System (INIS)

In the structural design of nuclear power plants, large bore hydraulic snubbers are used in the steam generator (SG) upper support system due to their ability to accommodate the large thermal movement of the SG during plant heatup/cooldown and yet provide restraint to the SG for dynamic loadings such as postulated piping rupture and seismic events. Due to the complexity of the control valve, hydraulic snubbers are very sensitive to abnormalities or changes in the hydraulic fluid. Additionally, snubber service life and operation are directly influenced by the durability of the snubber seal materials. Each of these factors significantly affects the operability of the hydraulic snubber and contributes to the continuing need to monitor and periodically test the performance of the snubbers. In light of the increasing costs to the utilities on the maintenance and testing of these snubbers, analytical methods were developed in order to eliminate all the large bore SG snubbers through the use of non-linear seismic analysis, innovative hardware design and modification, and component reserve design margins. The benefit of this snubber elimination program is to minimize plant operation costs through reductions in plant outage activities and man-rem exposures resulting from eliminated snubber inspection, testing, maintenance and refurbishment. This paper presents a procedure along with analytical techniques used in the non-linear seismic analysis for the snubber-eliminated supporanalysis for the snubber-eliminated support configuration. Through this non-linear time-history analysis technique, the analysis resulted in, generally, load reductions in the Reactor Coolant Loop (RCL) system since the original analysis was based on a very conservative response spectra analysis technique. Hence the system components are all qualified

242

Thermal hydraulic test for core cooling system using steam generators  

International Nuclear Information System (INIS)

As a candidate of the new concept safety system for the next generation PWR in Japan, the hybrid safety systems, which are combination of the active and the passive safety systems, and passive core cooling system by natural circulation in the reactor coolant loop with horizontal-type steam generators during Loss of Coolant Accidents (LOCAs) are investigated. The passive safety systems are advanced accumulators (ACC), primary-side and secondary-side automatic-depressurization systems (ADS, SADS), and a gravity-driven safety injection system (GDI). The horizontal steam generator design avoids a siphon break caused from the accumulation of non-condensable gases in the tubes by using a vent line in the channel head of the steam generators. This study investigates the passive core cooling characteristics of horizontal-type steam generators under LOCAs. The integrated thermal-hydraulic test has been performed at the Simulation Loop for the Innovative Mitsubishi Simplified PWR (SLIM) test facility. The facility simulates the prototype plant with the volumetric scaling ratio of 1/1000 and the elevation scaling ratio of 1/1. Experimental results show good vent performance of non-condensable gasses. Furthermore, experiments also show that after a large LOCA steady natural circulation in the reactor coolant loop is resumed after the break portion is submerged. Sufficient core cooling for both small and large LOCA was also confirmed. (author)hor)

243

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

244

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

245

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)

246

Research on hydraulic system of KZC-5 type rear dump truck in underground mine  

International Nuclear Information System (INIS)

KZC-5 type rear dump truck in underground mine is introduced in this paper. The determining principles and ways of two main hydraulic systems are discussed. It has been proved that the hydraulic systems are reasonable in the industrial scale test. (author)

247

MULTIFLEX: a FORTRAN-IV Computer Program for analyzing thermal-hydraulic-structure system dynamics  

International Nuclear Information System (INIS)

MULTIFLEX is a computer code to calculate hydraulic force for structure evaluation during the LOCA type transient. A description is given of the program and the mathematical representation of the thermal-hydraulic system interacting with the mechanical structure system. It also covers recommended modelings, code verification, and the post-processors, LATFORC and FORCE-2

248

MULTIFLEX: a FORTRAN-IV Computer Program for analyzing thermal-hydraulic-structure system dynamics. [PWR  

Energy Technology Data Exchange (ETDEWEB)

MULTIFLEX is a computer code to calculate hydraulic force for structure evaluation during the LOCA type transient. A description is given of the program and the mathematical representation of the thermal-hydraulic system interacting with the mechanical structure system. It also covers recommended modelings, code verification, and the post-processors, LATFORC and FORCE-2.

Takeuchi, K.; Kowalski, D.J.; Esposito, V.J.; Bordelon, F.M.

1976-02-01

249

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

OpenAIRE

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 ...

Tri-Vien Vu; Chih-Keng Chen; Chih-Wei Hung

2014-01-01

250

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

Directory of Open Access Journals (Sweden)

Full Text Available 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 team has jointly worked together with ANAV engineers at different levels in the analysis and improvement of these reactors. This article is an illustration of the usefulness of computational analysis for operational support. The contents presented were operational between 1985 and 2001 and subsequently changed slightly following various organizational adjustments. The paper has two different parts. In the first part, it describes the specific aspects of thermal-hydraulic analysis tasks related to operation and control and, in the second part, it briefly presents the results of three examples of analyses that were performed. All the presented examples are related to actual situations in which the scenarios were studied by analysts using thermal-hydraulic codes and prepared nodalizations. The paper also includes a qualitative evaluation of the benefits obtained by ANAV through thermal-hydraulic analyses aimed at supporting operation and plant control.

L. Batet

2007-11-01

251

A traversing system to measure bottom boundary layer hydraulic properties  

Science.gov (United States)

This study describes a new convenient and robust system developed to measure benthic boundary layer properties, with emphasis placed on the determination of bed shear stress and roughness height distribution within estuarine systems by using velocity measurements. This system consisted of a remotely operated motorised traverser that allowed a single ADV to collect data between 0 and 1 m above the bed. As a case study, we applied the proposed traversing system to investigate bottom boundary layer (BBL) hydraulic properties within Coombabah Creek, Queensland, Australia. Four commonly-employed techniques: (1) Log-Profile (LP); (2) Reynolds stress (RS); (3) Turbulent Kinetic Energy (TKE); and (4) Inertial Dissipation (ID) used to estimate bed shear stresses from velocity measurements were compared. Bed shear stresses estimated with these four methods agreed reasonably well; of these, the LP method was found to be most useful and reliable. Additionally, the LP method permits the calculation of roughness height, which the other three methods do not. An average value of bed shear stress of 0.46 N/m 2, roughness height of 4.3 mm, and drag coefficient of 0.0054 were observed within Coombabah Creek. Results are consistent with that reported for several other silty bed estuaries.

Ali, Ayub; Lemckert, Charles J.

2009-08-01

252

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

253

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.

254

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.

255

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

Science.gov (United States)

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.

Tatsumoto, H.; Shirai, Y.; Shiotsu, M.; Hata, K.; Kobayashi, H.; Naruo, Y.; Inatani, Y.; Kato, T.; Futakawa, M.; Kinoshita, K.

2010-06-01

256

Development of realistic thermal hydraulic system analysis code  

International Nuclear Information System (INIS)

The realistic safety analysis system is essential for nuclear safety research, advanced reactor development, safety analysis in nuclear industry and 'in-house' plant design capability development. In this project, we have developed a best-estimate multi-dimensional thermal-hydraulic system code, MARS, which is based on the integrated version of the RELAP5 and COBRA-TF codes. To improve the realistic analysis capability, we have improved the models for multi-dimensional two-phase flow phenomena and for advanced two-phase flow modeling. In addition, the GUI (Graphic User Interface) feature were developed to enhance the user's convenience. To develop the coupled analysis capability, the MARS code were linked with the three-dimensional reactor kinetics code (MASTER), the core thermal analysis code (COBRA-III/CP), and the best-estimate containment analysis code (CONTEMPT), resulting in MARS/MASTER/COBRA/CONTEMPT. Currently, the MARS code system has been distributed to 18 domestic organizations, including research, industrial, regulatory organizations and universities. The MARS has been being widely used for the safety research of existing PWRs, advanced PWR, CANDU and research reactor, the pre-test analysis of TH experiments, and others

257

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)

258

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

259

Thermal hydraulic design of safety grade decay heat removal system  

International Nuclear Information System (INIS)

In nuclear reactor, decay heat has to be removed with very high reliability. In Prototype Fast Breeder Reactor (PFBR) this is achieved by providing highly reliable Safety Grade Decay Heat Removal System (SGDHRS) in addition to the normal heat removal path. The SGDHRS consists of 4 independent circuits, each consisting of a sodium to sodium heat exchanger (DHX) and a sodium to Air Heat Exchanger (AHX). The DHX is a shell and tube type heat exchanger dipped in the hot pool of the reactor. The AHX is a finned tube sodium to air heat exchanger. Preliminary design of SGDHRS has been carried out by using one-dimensional model for the decay heat removal circuit with point models for its heat exchangers. Since the SGDHRS is a safety related system and its capacity dictates the maximum temperatures seen by various hot structures, it is essential to accurately estimate its capacity. Towards this multi-dimensional analyses have been carried out for important components of the system. This paper discusses about the thermal hydraulic models of SGDHRS components like DHX, AHX etc, computer codes used for the analyses and the results obtained. (authors)

260

Dynamic analysis program for hydraulic piping systems in nuclear power plants  

International Nuclear Information System (INIS)

A general purpose dynamic analysis program (GANET) for hydraulic piping network systems in nuclear power plants has been developed. This program solves coupled differential equations with a new matrix solution method, taking into account the changes in a network flow path pattern. Modeling for the control system with fundamental module units and a simplified method of initial calculations were introduced to realize a highly general applicability. Verification was performed by comparing the calculated results of the developed program to those from a detailed dynamic program for the condensate feedwater system in a BWR plant. Additional calculated results are presented on the application to the dynamic analysis of BWR auxiliary systems (water cleanup system). The results obtained to date demonstrate the modeling adequacy and program capabilities. (orig./HR)

261

Mode-2 hydraulic control of flow over a small ridge on a continental shelf  

Science.gov (United States)

Some of the most intense turbulence in the ocean occurs in hydraulic jumps formed in the lee of sills where flows are hydraulically controlled, usually by the first internal mode. Observations on the outer Texas-Louisiana continental shelf reveal hydraulic control of internal mode-2 lasting more than 3 h over a 20 m high ridge on the 100 m deep continental shelf. When control began the base of the weakly stratified surface layer bulged upward and downward, a signature of mode-2. As the westward flow producing control was lost, large-amplitude disturbances, initially resembling a bore in the weakly stratified layer, began propagating eastward. Average dissipation rates inferred from density inversions over the ridge were 10-8 and 10-7W kg-1, one to two decades above local background. Corresponding diapycnal diffusivities, K?, were 10-4 to 10-3 m2 s-1. Short-term mixing averages did not evolve systematically with hydraulic control, possibly owing to our inability to observe small overturns in strongly stratified water directly over the ridge. To test the feasibility of our interpretation of the observations, hydrostatic runs with a three-dimensional MITgcm simulated mode-2 control and intense mixing over the ridge below the interface. Details differed from observations, principally because we lacked three-dimensional density fields to initialize the model which was forced with currents observed by a bottom-mounted ADCP several kilometers east of the ridge. Consequently, the model did not capture all flow features around the bank. The principal conclusion is that hydraulic responses to higher modes can dominate flows around even modest bathymetric irregularities.

Gregg, M. C.; Klymak, Jody M.

2014-11-01

262

Hydraulic investigations of sediment-water-systems from the Gorleben region  

International Nuclear Information System (INIS)

Radionuclide migration in sediment-water-systems is determined, in addition to the sorption of the radionuclide, by the physical interactions of the flowing groundwater and granular skeleton of the sediment, which are called the hydraulic properties of the system sediment/water. Hydraulic properties of the system sediment/water which are important for pollutant migration are its permeability, effective porosity, and hydrodynamic dispersion. The results of the hydraulic investigations of sediment-water-systems from the Gorleben region are summarized. (orig./DG)

263

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

264

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

265

Hydraulic and thermal performance assessment of cooling water systems at E.I. Hatch Nuclear Plant  

International Nuclear Information System (INIS)

In July, 1989, the U. S. Nuclear Regulatory Commission issued Generic Letter 89-13, open-quotes Service Water Problems Affecting Safety-Related Equipmentclose quotes. The Generic Letter was issued because of observed operating problems with corrosion, erosion, biological fouling, silting, and protective coating failure in safety-related heat exchangers and associated cooling water piping at several nuclear power plants. The NRC required that utilities with operating nuclear plants establish a plan for comprehensive evaluation of their open cycle Service Water Systems, including: ongoing surveillance and control; testing of safety-related heat exchangers to verify heat transfer capability; inspection and maintenance of piping and water-cooled heat exchangers; confirmation that the service water system is capable of performing its intended function in accordance with the plant design basis; confirmation that maintenance and operating practices, emergency procedures, and training are adequate to ensure that safety-related equipment will perform as intended. As an integral part of the Georgia Power Company response to the Generic Letter, a personal computer-based hydraulic flow model was developed for the Plant Service Water Systems (PSW) on both units of the E. I. Hatch Nuclear Plant (HNP). The Bechtel-developed BALANCE program and PLANTSIM option were selected for this effort. Bechtel's hydraulic network computer program was developed and used successfully for flow balaeloped and used successfully for flow balancing at the Limerick Generating Station during initial plant startup. The BALANCE hydraulic network model provides an accurate analytical representation of the Hatch Plant Service Water System on each unit. A summary of program capabilities and modeling assumptions, as well as observations which have been made by comparison of program predictions with test results, is presented here

266

For God (or) country: the hydraulic relation between government instability and belief in religious sources of control.  

Science.gov (United States)

It has been recently proposed that people can flexibly rely on sources of control that are both internal and external to the self to satisfy the need to believe that their world is under control (i.e., that events do not unfold randomly or haphazardly). Consistent with this, past research demonstrates that, when personal control is threatened, people defend external systems of control, such as God and government. This theoretical perspective also suggests that belief in God and support for governmental systems, although seemingly disparate, will exhibit a hydraulic relationship with one another. Using both experimental and longitudinal designs in Eastern and Western cultures, the authors demonstrate that experimental manipulations or naturally occurring events (e.g., electoral instability) that lower faith in one of these external systems (e.g., the government) lead to subsequent increases in faith in the other (e.g., God). In addition, mediation and moderation analyses suggest that specific concerns with order and structure underlie these hydraulic effects. Implications for the psychological, sociocultural, and sociopolitical underpinnings of religious faith, as well as system justification theory, are discussed. PMID:20954784

Kay, Aaron C; Shepherd, Steven; Blatz, Craig W; Chua, Sook Ning; Galinsky, Adam D

2010-11-01

267

Digital imaging system and virtual instrument platform for measuring hydraulic conductivity of vascular endothelial monolayers.  

Science.gov (United States)

We have developed an automated, digital imaging system, controlled by two virtual instruments, to measure hydraulic conductivity (Lp) of cultured endothelial monolayers. Live digital images of multiple independent experiments were captured by custom-designed video processing software running in National Instruments LabVIEW 6.1. Fluid displacement data are automatically displayed in real time as both volumetric flux (Jv) and hydraulic conductivity (Lp). A separate data analysis program is used to display permeability values from stored displacement measurements and displays Jv or Lp of each monolayer. Optional statistical filters have been included to aid in data analysis. This new digital permeability system is able to measure flux rates over a dynamic range from 10(-9) cm/s/cm H2O to 10(-4) cm/s/cm H2O. Values obtained for cultured lung microvascular Lp are nearly identical to other cultured endothelial monolayers and also to values obtained in-vivo using the Landis-Michel technique and the split-drop method. The use of a commercially available platform allows the system configuration to be easily modified to suit the experimental needs. The technical development of this system is described in detail. PMID:16530229

Hubert, Christopher G; McJames, Scott W; Mecham, Ian; Dull, Randal O

2006-03-01

268

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

269

Electric vehicle regenerative antiskid braking and traction control system  

Science.gov (United States)

An antiskid braking and traction control system 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 one or more 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 sensors and determining if regenerative antiskid braking control, requiring hydraulic braking control, or requiring traction control are required. The processor then employs a control strategy based on the determined vehicle state and provides command signals to a motor controller to control the operation of the electric traction motor and to a brake controller to control fluid pressure applied at each vehicle wheel to provide the appropriate regenerative antiskid braking control, hydraulic braking control, and traction control. 10 figs.

Cikanek, S.R.

1995-09-12

270

Design and development of water hydraulic pressure compensated flow control valve  

International Nuclear Information System (INIS)

The Pressure Compensated Flow Control Valves (PCFCVs) are required for maintaining constant flow in a hydraulic circuit as there is fluctuation in supply or return pressure and other resistance on actuators. The water hydraulic PCFCV has been designed which can control the load flow as well as pump pressure. For achieving constant flow requirement, a hydrostate has been designed which maintains a constant differential pressure across a manually settable valve and hence maintain constant flow across the valve. The pump pressure control is achieved by controlling the sensing line pressure of hydrostate with the help of an air piston actuated pilot operated relief valve. The paper discusses conceptual design, mathematical modelling, parameter optimization and design of PCFCV. (author)

271

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

272

How far can various control options take us in terms of increased hydraulic capacity under wet weather conditions?  

DEFF Research Database (Denmark)

Many modelling studies have demonstrated that the hydraulic capacity of the WWTP can be improved by introducing various real time control options, however few studies have demonstrated how effective these controls are in the real world.

Sharma, Anitha Kumari; Guildal, T.

273

Hybrid Control System for the ATLAS Facility  

International Nuclear Information System (INIS)

A thermal-hydraulic integral effect test (IET) loop, advanced thermal-hydraulic test loop for accident simulation (ATLAS), has been constructed in the Korea Atomic Energy Research Institute (KAERI). For the data acquisition and control system, hybrid control system (HCS) was adopted to enhance the integrated performance of demanding process control application for acquiring of experimental data. The whole feature of the data acquisition and control system consists of 1 set of the HCS for headware connection, 1 server station for signal processing schemes, 1 engineering work station (EWS) for control logics, and 3 operator interface station (OPS) for human-machine interface. The total number of signals for the data acquisition and the system control of the atlas facility is up to about 2010 channels, which are distributed in 16 chasses which are installed in 10 cabinets. The main focus of this paper is to present the technical configuration of the HCS of the atlas facility

274

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

Energy Technology Data Exchange (ETDEWEB)

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).

Jung, Moon Kee; Park, Choon Kyung; Yang, Sun Kyoo; Chun, Se Yung; Song, Chul Hwa; Jun, Hyung Kil; Jung, Heung Joon; Won, Soon Yun; Cho, Yung Roh; Min, Kyung Hoh; Jung, Jang Hwan; Jang, Suk Kyoo; Kim, Bok Deuk; Kim, Wooi Kyung; Huh, Jin; Kim, Sook Kwan; Moon, Sang Kee; Lee, Sang Il [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1995-06-01

275

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)

276

Steam-Hydraulic Turbines Load Frequency Controller Based on Fuzzy Logic Control  

OpenAIRE

This study investigates an application of the fuzzy logic technique for designing the load-frequency control system to damp the frequency and tie line power oscillations due to different load disturbances under the governor deadzones and GRC non-linearity. Integral controller are designed and compared with the proposed fuzzy logic controller. To validate the effectiveness of the proposed controller, two-area load frequency power system is simulated over a wide range of operating conditions an...

Yousef, Ali M.; Khamaj, Jabril A.; Ahmad Said Oshaba

2012-01-01

277

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

278

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

279

Design of the cadastre and data structure for hydraulics modeling of water supply systems  

OpenAIRE

Diploma graduation deals with the possibility how to set up a hydraulic cadastre and system for hydraulic modeling of water supply systems. In the context of the diploma task a few software tools was created to connect and edit data in GIS, and a tool for exporting hydraulic calculation results to Google Earth. Software tools have been written in VBA and. NET technology. The data were obtained and analyzed from different GIS and other data stores. The possibility of using data from the accoun...

Lipovs?ek, Srec?ko

2008-01-01

280

Modelling and Control of a Complementary Energy Recuperation System for Mobile Working Machines  

OpenAIRE

The concept of hybrid technologies for mobile working machines has gained increased attention in recent years. This paper deals with a parallel hybrid system for energy recuperation based on a two-machine hydraulic transformer. The system can be connected hydraulically to an existing hydraulic circuit as a complementary add-on system. The linear analysis of the system visualises the control difficulties coming from a low inertia, slow control dynamics of the machines and the non-linear stick-...

Hugo, Anton; Pettersson, Karl; Heybroek, Kim; Krus, Petter

2013-01-01

281

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.

Watsonville Environmental Science Workshop

2011-01-01

282

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

283

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)

284

Finite-time convergent continuous control design based on sliding mode algorithms with application to a hydraulic drive  

DEFF Research Database (Denmark)

Sliding modes impose strong robustness toward parametric plant uncertainties and disturbances and provide for accurate tracking performance in control systems. However, in physical systems the application of sliding modes may give rise to undesirable chattering of the control signal due to actuator dynamics, possible excitation of unmodelled dynamics and structural resonant modes of load systems, etc. This may be avoided by application of smoothing functions imposing boundary layers on the control constraint, or by carrying out the design in relation to the control derivative. However, such boundary layers introduce additional design parameters and actuator dynamics may not allow the desired control accuracy to be reached. In this paper continuous controllers are proposed, with the designs taking their offset in some well-known sliding controllers. The proposed controllers preserve the finite-time convergence properties known from sliding control while at the same time avoiding control chattering, however, onthe cost of robustness. Experimental results confirm the announced properties when applied to a hydraulic valve-cylinder drive, and demonstrates superior performance over conventional linear controllers.

Schmidt, Lasse; Andersen, Torben Ole

2014-01-01

285

Study of an open circut hydraulic power system with compact cooler-reservoir unit  

OpenAIRE

In this research, a complete open hydraulic drive mixer system has been designed, instrumented and commissioned, and an extensive programme of experimental tests has been undertaken to 1)- investigate the effectiveness of a cooling unit as an integral part of the open hydraulic system and 2)- validate the mathematical model. The results have shown that the working temperature could be reduced by 40 % by using the integral cooling/reservoir unit and the temperature is always kept below the rec...

Al-natour, Ibrahim Subhi

1992-01-01

286

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

287

Performance Test of the Damping System Using a Spring-Hydraulic Damper  

International Nuclear Information System (INIS)

A control element drive mechanism (CEDM) is a reactor regulating system, which is to insert, withdraw or maintain a control rod containing a neutron absorbing material within a reactor core to control the reactivity of the core. The ball-screw type CEDM for the small and medium research reactor is under development in KAERI. The CEDM is placed at the top of the reactor pressure vessel head, and is connected with the top of the control element assembly located in the reactor core through the extension shaft. The CEDM consists of the pressure vessel, the step motor, the gear and the ball-screw assembly. Also, to reduce the impact force due to the free drop of the movable parts in the emergent situation, a damping system using a spring-hydraulic damper is installed at the top of ball-screw assembly. This paper describes the experimental results to verify the damping performance in case of the emergent drop of the CEDM. The performance tests are performed by using a full-scale structure except the control element assembly, and a displacement after an impact of a guide shaft and the damping system is measured by using a linear variable differential transformer (LVDT). The influence of the drop height on the damping behavior is also estimated on the basis of test results

288

Performance Test of the Damping System Using a Spring-Hydraulic Damper  

Energy Technology Data Exchange (ETDEWEB)

A control element drive mechanism (CEDM) is a reactor regulating system, which is to insert, withdraw or maintain a control rod containing a neutron absorbing material within a reactor core to control the reactivity of the core. The ball-screw type CEDM for the small and medium research reactor is under development in KAERI. The CEDM is placed at the top of the reactor pressure vessel head, and is connected with the top of the control element assembly located in the reactor core through the extension shaft. The CEDM consists of the pressure vessel, the step motor, the gear and the ball-screw assembly. Also, to reduce the impact force due to the free drop of the movable parts in the emergent situation, a damping system using a spring-hydraulic damper is installed at the top of ball-screw assembly. This paper describes the experimental results to verify the damping performance in case of the emergent drop of the CEDM. The performance tests are performed by using a full-scale structure except the control element assembly, and a displacement after an impact of a guide shaft and the damping system is measured by using a linear variable differential transformer (LVDT). The influence of the drop height on the damping behavior is also estimated on the basis of test results.

Choi, Myoung Hwan; Kim, Ji Ho; Huh, Hyung; Yu, Je Yong; Sohn, Dong Seong [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2009-10-15

289

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

290

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

291

Algorithm for automatic manufacturing control of general hydraulic surface.  

Czech Academy of Sciences Publication Activity Database

Praha : Faculty of Transportation Sciences CTU, Institute of Theoretical and Applied Mechanics AS CR Czech Society of Mechanics, 2001 - (Jírová, J.; Jiroušek, O.; Kult, J.), s. 285-290 ISBN 80-86246-09-4. [International Conference Experimental Stress Analysis 2001 /39./. Tábor (CZ), 04.06.2001-06.06.2001] R&D Projects: GA MŠk LN00A015 Institutional research plan: CEZ:AV0Z1010921 Keywords : automatic control * error function * trend function * total deviation function Subject RIV: BH - Optics, Masers, Lasers

Rössler, Tomáš; Hrabovský, Miroslav

292

Hydraulic balancing of a control component within a nuclear reactor  

International Nuclear Information System (INIS)

A reactor control component includes an inner conduit, for instance containing neutron absorber elements, adapted for longitudinal movement within an outer guide duct. A transverse partition partially encloses one end of the conduit and meets a transverse wall within the guide duct when the conduit is fully inserted into the reactor core. A tube piece extends from the transverse partition and is coaxially aligned to be received within a tubular receptacle which extends from the transverse wall. The tube piece and receptacle cooperate in engagement to restrict the flow and pressure of coolant beneath the transverse partition and thereby minimize upward forces tending to expel the inner conduit

293

Experimental assessment of control plug hydraulics in PFBR  

International Nuclear Information System (INIS)

Control Plug (CP) is an important component in a Liquid Metal Cooled Fast Breeder Reactor (LMFBR). It houses Absorber Rod Drive Mechanisms (ARDM) for controlling the reactor power and shutting down the reactor when there is a requirement. It also houses thermocouples for monitoring the core outlet temperature and safety related component like Failed Fuel Localization Modules (FFLM). CP is a cylindrical porous shell and located vertically right above the core. A portion of sodium flow coming out from the core enters the CP. This sodium flows inside the CP and exits from porous outer shell to finally mix with the hot plenum. High magnitude of sodium cross flow velocity inside the CP may cause Flow Induced Vibration (FIV) to the internal components. Hence it is very important to know the velocity distribution inside the CP. Calculating the velocity distribution inside the CP using computational technique is difficult because the internal geometry of CP is very complex. Therefore experiments have been carried out to measure velocity inside the CP in a large scale (1/4 scale) model of Prototype Fast Breeder Reactor (PFBR) using water as simulant and respecting the appropriate similarity criteria. Finally the model measurements have been extrapolated to prototype condition. (author)

294

Application of flow network models of SINDA/FLUINTTM to a nuclear power plant system thermal hydraulic code  

International Nuclear Information System (INIS)

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/FLUINTTM 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)

295

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

296

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

297

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

298

A conceptual model of check dam hydraulics for gully control  

OpenAIRE

There is little information in scientific literature regarding the modifications induced by check dam systems in flow regimes in restored gully reaches, despite it being a crucial issue for the design of conservation measures. Here, we develop a conceptual model to classify flow regimes in straight rectangular channels for initial and dam-filling conditions as well as a method of estimating efficiency in order to provide guidelines for optimal design. The model integrates several previous mat...

Castillo, C.; Pe?rez, R.; Go?mez, J. A.

2013-01-01

299

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

300

SBC - the electro-hydraulic brake system from Mercedes-Benz; SBC - Die elektrohydraulische Bremse von Mercedes-Benz  

Energy Technology Data Exchange (ETDEWEB)

The electro-hydraulic brake (EHB) is the first generation of future 'Brake-by-Wire' systems for cars. EHB is a new mechatronic brake system, which links adaptive, digital control technology with integrated pressure sensors and high-precision hydraulic valves which are, however, fit for volume production. It permits highly dynamic, individual wheel brake pressure control which provides excellent stability and optimum short braking distances. The 'Brake-by-Wire' interface of the system permits driver-independent brake applications to improve vehicle safety. The system is developed by DaimlerChrysler in co-operation with the system supplier Robert Bosch under the brand name SBC (Sensotronic Brake Control) to series manufacture. (orig.) [German] Die elektrohydraulische Bremse EHB ist die erste Generation kuenftiger 'Brake-by-Wire'-Systeme im PKW. EHB ist ein neues mechatronisches Bremsensystem, das adaptive, digitale Regeltechnik mit integrierter Drucksensorik und hochpraezisen aber grossserienfaehigen Hydraulikventilen verbindet. Es ermoeglicht eine hochdynamische, radindividuelle Bremsdruckregelung fuer hervorragende Stabilitaet und optimal kurze Bremswege. Die 'Brake-by-Wire'-Schnittstelle des Systems gestattet fahrerunabhaengige Bremseneingriffe zur Verbesserung der Fahrzeugsicherheit. Das System wird von DaimlerChrysler in Zusammenarbeit mit dem Systemlieferanten Robert Bosch unter dem Markennamen SBC (Sensotronic Brake Control) zur Serienreife zu entwickeln. (orig.)

Stoll, U.

2000-07-01

301

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

302

Estimating biozone hydraulic conductivity in wastewater soil-infiltration systems using inverse numerical modeling.  

Science.gov (United States)

During operation of an onsite wastewater treatment system, a low-permeability biozone develops at the infiltrative surface (IS) during application of wastewater to soil. Inverse numerical-model simulations were used to estimate the biozone saturated hydraulic conductivity (K(biozone)) under variably saturated conditions for 29 wastewater infiltration test cells installed in a sandy loam field soil. Test cells employed two loading rates (4 and 8cm/day) and 3 IS designs: open chamber, gravel, and synthetic bundles. The ratio of K(biozone) to the saturated hydraulic conductivity of the natural soil (K(s)) was used to quantify the reductions in the IS hydraulic conductivity. A smaller value of K(biozone)/K(s,) reflects a greater reduction in hydraulic conductivity. The IS hydraulic conductivity was reduced by 1-3 orders of magnitude. The reduction in IS hydraulic conductivity was primarily influenced by wastewater loading rate and IS type and not by the K(s) of the native soil. The higher loading rate yielded greater reductions in IS hydraulic conductivity than the lower loading rate for bundle and gravel cells, but the difference was not statistically significant for chamber cells. Bundle and gravel cells exhibited a greater reduction in IS hydraulic conductivity than chamber cells at the higher loading rates, while the difference between gravel and bundle systems was not statistically significant. At the lower rate, bundle cells exhibited generally lower K(biozone)/K(s) values, but not at a statistically significant level, while gravel and chamber cells were statistically similar. Gravel cells exhibited the greatest variability in measured values, which may complicate design efforts based on K(biozone) evaluations for these systems. These results suggest that chamber systems may provide for a more robust design, particularly for high or variable wastewater infiltration rates. PMID:17449084

Bumgarner, Johnathan R; McCray, John E

2007-06-01

303

A study of passive and adaptive hydraulic engine mount systems with emphasis on non-linear characteristics  

Science.gov (United States)

Passive hydraulic mounts exhibit excitation frequency variant and deflection amplitude sensitive stiffness and damping properties. Such non-linear dynamic characteristics are examined by using analytical and experimental methods, both at the device level and within the context of a simplified vehicle model. A new lumped parameter non-linear mathematical model of the hydraulic mount is developed by simulating its decoupler switching mechanism and inertia track dynamics. The low frequency performance features and limitations of several passive mounts are made clear through the non-linear vehicle model simulation and comparable laboratory vibration tests. The high frequency performance problems of the passive hydraulic mount are identified by applying the quasi-linear analysis method. Based on these results, a new adaptive mount system is developed which exhibits broad bandwidth performance features up to 250 Hz. It implements an on-off damping control mode by using engine intake manifold vacuum and a microprocessor based solenoid valve controller. A laboratory bench set-up has already demonstrated its operational feasibility. Through analytical methods, it is observed that our adaptive mount provides superior dynamic performance to passive engine mounts and comparable performance to a small scale active mount over a wide frequency range, given the engine mounting resonance control, shock absorption and vibration isolation performance requirements. Although technical prospects of the proposed adaptive system appear promising, the in situperformance needs to be evaluated.

Kim, G.; Singh, R.

1995-01-01

304

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)

305

Anastomosing reach control on hydraulics and sediment distribution on the Sabie River, South Africa  

Science.gov (United States)

Rivers in the Kruger National Park, South Africa, have variable degrees of bedrock and alluvial influence. Pre-2000 aerial imagery for the Sabie River (catchment area 6320 km2) reveals downstream alternations from alluvial single thread or braided, to bedrock anastomosed or mixed anastomosed channel types, with pool-rapids also present locally. In 2000 and 2012, extreme floods resulted in significant alluvial erosion, widely exposing the underlying bedrock. Since the 2012 flood, aerial LiDAR surveys reveal the strong gradient control exerted by the bedrock and mixed anastomosed channel types, which influences hydraulic conditions and sediment dynamics. Two dimensional hydraulic modelling of moderate floods (3500 m3 s-1), the bedrock or mixed anastomosed channel types are drowned out, resulting in dramatically increased velocities along the entire river and widespread alluvial stripping regardless of initial channel type or location.

Entwistle, N.; Heritage, G.; Tooth, S.; Milan, D.

2015-03-01

306

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

307

Summary and evaluation of available hydraulic property data for the Hanford Site unconfined aquifer system  

International Nuclear Information System (INIS)

Improving the hydrologic characterization of the Hanford Site unconfined aquifer system is one of the objectives of the Hanford Site Ground-Water Surveillance Project. To help meet this objective, hydraulic property data available for the aquifer have been compiled, mainly from reports published over the past 40 years. Most of the available hydraulic property estimates are based on constant-rate pumping tests of wells. Slug tests have also been conducted at some wells and analyzed to determine hydraulic properties. Other methods that have been used to estimate hydraulic properties of the unconfined aquifer are observations of water-level changes in response to river stage, analysis of ground-water mound formation, tracer tests, and inverse groundwater flow models

308

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

309

Hydraulic Plant Remote Laboratory  

OpenAIRE

In this paper we present a three tank hydraulic system and possibilities how it can be used for the purpose of remote laboratories. The concept of our remote laboratory is based on client – server architecture. We compare two different approaches of remote control. First one uses a Java Server application implemented together with a control algorithm on the server side. In this case the control algorithm is realized in the Matlab/Simulink environment. There is necessary to exchange data bet...

Vladimir Zilka; Pavol Bisták; Peter Kurcik

2008-01-01

310

Mechanical Engineering Design Project report: Enabler control systems  

Science.gov (United States)

The Controls Group was assigned the responsibility for designing the Enabler's control system. The requirement for the design was that the control system must provide a simple user interface to control the boom articulation joints, chassis articulation joints, and the wheel drive. The system required controlling hydraulic motors on the Enabler by implementing 8-bit microprocessor boards. In addition, feedback to evaluate positions and velocities must be interfaced to provide the operator with confirmation as well as control.

Cullen, Christian; Delvecchio, Dave; Scarborough, Alan; Havics, Andrew A.

1992-01-01

311

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

312

Polymer-based micro flow sensor for dynamical flow measurements in hydraulic systems  

International Nuclear Information System (INIS)

In this paper we present a micro flow sensor from a polymer for dynamical flow measurements in hydraulic systems. The flow sensor is based on the thermal anemometric principle and consists of two micro-structured housing shells from polysulfone (PSU) which form a small fluidic channel with a cross-section of 580 µm × 400 µm. In between there is a thin polyimide membrane supporting three gold track structures forming an electrical heater and two resistive thermometers which allows the detection of the flow direction, too. The complete sensor is inserted into the hydraulic system, but only a small bypass flow is directed through the fluidic channel by means of a special splitting system. Due to its small heat capacity, the sensor is suitable to detect flow pulsations up to about 1200 Hz which allows the sensor to be used for the condition monitoring or preventive maintenance of hydraulic systems.

313

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)

314

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)

315

Modernization of the turbine control technique and the turbine hydraulics aimed to improved maneuverability in the load range, system safety and plant availability, plant transparency for diagnosis and long-term performance; Modernisierung der Turbinenleittechnik und der Turbinenhydraulik mit den Zielen: Verbesserung Manoevrierfaehigkeit im Lastbetrieb, System-Sicherheit und Anlagenverfuegbarkeit, Anlagentransparenz fuer Diagnose und langfristige Betriebserhaltung  

Energy Technology Data Exchange (ETDEWEB)

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

Baran, Detlef [Helmut Mauell GmbH, Velbert (Germany)

2012-11-01

316

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)

317

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.

318

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

Science.gov (United States)

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.

Zhang, Q. H.; Xu, Y.; Shi, W. D.; Lu, W. G.

2012-11-01

319

Upper and Middle Tiete River Basin dam-hydraulic system, travel time and temperature modeling  

Science.gov (United States)

SummaryTiete River System in the State of Sao Paolo, Brazil is characterized by complex hydraulics and operational problems due to series of dams and point and diffuse inflows along the river. A one dimension Lagrangian river model was developed and applied to the 313 km reach of the Upper and Middle Tiete River Basin from the Penha Dam to the head water of Bara Bonita Reservoir, a stretch of river that includes six small to medium size dams (3.4-22 m high) including the Pirapora Reservoir and 26 inflows into the river (11 tributaries, 9 diffuse source areas, and discharges of 4 cities stormwater and 2 wastewater treatment plants. The conservative tracer transport and temperature model that accounts for the short and long wave radiation and heat transfers at the free surface was included and solved using the Crank-Nicholson scheme. The time variable catchment input to the model was the simulated output of the external hydrological model called Runoff Load Model which results were provided by CETESB. The numerical treatment of series of dams and spillway (that included uncontrolled overflow spillway, gate-controlled ogee spillway; and underflow gates and tunnels) and parameterisation of hydraulic jumps are described. Special attention was focused on the high spatial and temporal variation of flows in Tiete River Basin, a result of the large variation in catchment inflows and channel geometry due to dams and reservoirs along the river. Predicted and measured spatial and seasonal variation of flow and temperature profiles along the river show good agreement. The simulated travel time of conservative tracer is compared against the CETESB's 1982 and 1984 field study data in a 254 km reach of the Middle Tiete River that again shows good agreement. Being Lagrangian in construction, this new model is computationally efficient making it an ideal tool for long term simulation for water resource planning, management and operation decision making in a large and complex river basin system.

Devkota, Bishnu; Imberger, Jörg

2012-12-01

320

Step dynamic process of the hydraulically-driven control rod, 1. Experiment of dynamic process behavior  

International Nuclear Information System (INIS)

The step dynamic process of the hydraulic control rod (HCR) has been achieved by experiments. This paper reveals the action mechanism of the HCR, gives detailed analyses of the relationship among the dynamic feature, the control rod and combined valve performance parameters, and the combined valve operation. The results indicate that the step process of the control rod is affected by the output flow pulse of the combined valve, pressure wave, and heavily damped pressure oscillation that is produced by the step cylinder movement. The performance parameters of the step cylinder limit the flow range in its stationary balanced state and also limit the capability of absorbing the flow pulse and pressure wave in its step process. The performance parameters of the combined valve determine the quantitative values of stationary balance, delay balance, flow pulse and pressure wave. The relation of both parameters determines the step state of the control rod. (author)

321

Design strategy for improving the energy efficiency in series hydraulic/electric synergy system  

International Nuclear Information System (INIS)

Battery is a vital subsystem in an electric vehicle with regenerative braking system. The energy efficiency of an electric vehicle is improved by storing the regenerated energy in an electric battery, during braking, and reusing it during subsequent acceleration. Battery possesses a relatively poor power density and slow charging of regenerated energy, when compared to hydro-pneumatic accumulators. A series hydraulic/electric synergy system – an energy efficient mechatronics system is proposed to overcome the drawbacks in the conventional electric vehicle with regenerative braking. Even though, electric battery provides higher energy density than the accumulator system, optimal sizing of the hydro-pneumatic accumulator and other process parameters in the system to provide better energy density and efficiency. However, a trade-off prevails between the system energy delivered and energy consumed. This gives rise to a multiple objective problem. The proposed multi-objective design optimization procedure based on an evolutionary strategy algorithm maximizes the energy efficiency of the system. The system simulation results after optimization show that, the optimal system parameters increase the energy efficiency by 3% and hydraulic regeneration efficiency by 17.3%. The suggested design methodology provides a basis for the design of a series hydraulic/electric synergy system as energy efficient and zero emission system. - Highlights: • Dynamic analysis of SHESS to investigate energy efficiency. • Optimization of system parameters based on multi-objective design strategy. • Evaluation of improvements in system energy efficiency and hydraulic regeneration energy. • Identification of conditions at which hydraulic regenerative efficiency is maximized for minimum energy consumption. • Results confirm advantages of using SHESS

322

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

323

High speed hydraulically-actuated operating system for an electric circuit breaker  

Science.gov (United States)

This hydraulically-actuated operating system comprises a cylinder, a piston movable therein in an opening direction to open a circuit breaker, and an accumulator for supplying pressurized liquid to a breaker-opening piston-actuating space within the cylinder. A normally-closed valve between the accumulator and the actuating space is openable to allow pressurized liquid from the accumulator to flow through the valve into the actuating space to drive the piston in an opening direction. A dashpotting mechanism operating separately from the hydraulic actuating system is provided, thereby reducing flow restriction interference with breaker opening. 3 figs.

Iman, I.

1983-06-07

324

Cluster-based representation of hydraulic systems. [stable (closed valve) and unstable (open valve) states  

Science.gov (United States)

The authors present a technique for structural abstraction applicable to the domain of pressurized hydraulic systems. Valves, when closed, functionally isolate clusters of components; when opened, neighboring clusters are merged. A cluster can only be in the one of two qualitative states-stable, where pressures are equal throughout and no flow occurs, or unstable, where flow from high-pressure source(s) to low-pressure sink(s) occurs. Reasoning in terms of clusters is shown to facilitate the generation and explanation of plans for operating and troubleshooting hydraulic systems.

Farley, Arthur M.

1988-01-01

325

Climatic controls on soil hydraulic properties along soil chronosequences on volcanic parent material  

Science.gov (United States)

Soil development is influenced by physical and chemical weathering processes and accumulation of eolian sediment. These weathering processes have often been examined using chronosequences that take advantage of deposited lava flows ranging in age. These studies typically characterize the physical and sometimes chemical properties, but rarely have these studies examined how hydraulic properties change with time. In addition, many of these studies occur in tropical climates where weathering occurs rapidly; relatively little is known about weathering processes in cool dry climates. This is important not only to understand how water and energy move in these water limited systems, but also to understand how they might change as climate patterns shift. The objectives of this research were to 1) measure and model the soil water retention, ?(h), and hydraulic conductivity, K(h), functions across a chronosequence of cinder cone sites in a cold desert region, 2) compare soil hydraulic properties across soil ages to examine how soil development in semi-arid climates moderates soil hydraulic processes, and 3) compare soil hydraulic characteristics in a dryland environment to those of a wet tropical climate across similarly aged lava flows. We contrast 2.1, 6.9 and 13.9 ka cinder cones soils at Craters of the Moon (COTM) National Monument, Idaho, USA. Soil development at COTM is sparse and is concentrated in joints and crevices of the basalt. The soils contrast slightly in texture with age. The young (2.1 ka) soils are coarser grained with at least 20% greater sand content than the older (6.9, 13.9 ka) soils. Preliminary hydraulic modeling suggests that older soils have lower ? values than younger soils. This is likely due to a higher bulk density values from higher accumulations of secondary minerals in the old soils from loess input. The models show that the air entry points (?) occur at lower tensions in the young soils, likely caused by a greater pore size distribution. We observe that ? decreases with age, and ? occurs at higher tensions. Soil horizons are developed dominantly on the cinder cones. These model estimates appear to match well with preliminary field measurements. Tropical climates enhance the weathering of basaltic parent material. The mean annual precipitation in the Hawaiian site is 2500 mm, and 310 mm at COTM. Accumulation of rainfall increases the weathering rate of the parent material. Using previous work characterizing the physical characteristics of soil across the Hawaii chronosequence to model the contrasting soils, we found that the 0.3 and 20 ka Hawaii soils had similar hydraulic properties; ? values were approximately 0.45 cm3/cm3 and Ks values were 6 cm/hr. However, these Hawaiian soils contrasted and were quantitatively lower than the entire COTM chronosequence. At the 2.1 ka COTM soil, Ks was 17 cm/hr and ? was 0.52-0.65 cm3/cm3 whereas at the 13.9 ka soil, Ks was 12 cm/hr and ? was 0.52 cm3/cm3. The 0.3 ka Hawaiian soil had a 20-30% higher silt content than the 2.1 ka COTM soil. Our models help quantify rates of soil development and hydraulic properties developed through time on volcanic parent materials.

Beal, L. K.; Lohse, K. A.; Godsey, S.; Huber, D. P.

2013-12-01

326

Electric vehicle regenerative antiskid braking and traction control system  

Science.gov (United States)

An antiskid braking and traction control system 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 one or more 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 sensors and determining if regenerative antiskid braking control, requiring hydrualic braking control, or requiring traction control are required. The processor then employs a control strategy based on the determined vehicle state and provides command signals to a motor controller to control the operation of the electric traction motor and to a brake controller to control fluid pressure applied at each vehicle wheel to provide the appropriate regenerative antiskid braking control, hydraulic braking control, and traction control.

Cikanek, Susan R. (Wixom, MI)

1995-01-01

327

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

328

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

329

Practical experience of the main primary system hydraulic tests for Qinshan NPP phase II  

International Nuclear Information System (INIS)

Initial hydraulic test during commissioning and test renewal during refueling outage were performed once for unit 1 and 2 of Qinshan II respectively, all safety class 1 pressure-retaining components were subjected to 22.8 MPa in initial hydraulic test and 20.6 MPa in test renewal. Based on the practice of the four times successful hydraulic test of the main primary system for Qinshan II, the RCC-M and RSEM requirements related, brief test process and main results etc were introduced, and the differences between initial test and test renewal, as well as the risks, precautions and practical experience were summed up. They will be beneficial for the same kind PWR nuclear power plants. (authors)

330

The response of Pinus sylvestris to drought: stomatal control of transpiration and hydraulic conductance.  

Science.gov (United States)

We investigated the impact of drought on the physiology of 41-year-old Scots pine (Pinus sylvestris L.) in central Scotland. Measurements were made of the seasonal course of transpiration, canopy stomatal conductance, needle water potential, xylem water content, soil-to-needle hydraulic resistance, and growth. Comparison was made between drought-treated plots and those receiving average precipitation. In response to drought, transpiration rate declined once volumetric water content (VWC) over the top 20 cm of soil reached a threshold value of 12%. Thereafter, transpiration was a near linear function of soil water content. As the soil water deficit developed, the hydraulic resistance between soil and needles increased by a factor of three as predawn needle water potential declined from -0.54 to -0.71 MPa. A small but significant increase in xylem embolism was detected in 1-year-old shoots. Stomatal control of transpiration prevented needle water potential from declining below -1.5 MPa. Basal area, and shoot and needle growth were significantly reduced in the drought treatment. In the year following the drought, canopy stomatal conductance and soil-to-needle hydraulic resistance recovered. Current-year needle extension recovered, but a significant reduction in basal area increment was evident one year after the drought. The results suggest that, in response to soil water deficit, mature Scots pine closes its stomata sufficiently to prevent the development of substantial xylem embolism. Reduced growth in the year after a severe soil water deficit is most likely to be the result of reduced assimilation in the year of the drought, rather than to any residual embolism carried over from one year to the next. PMID:12651364

Irvine, J.; Perks, M. P.; Magnani, F.; Grace, J.

1998-06-01

331

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.

332

Soil micromorphological study for assessment of soil porous system, soil hydraulic properties and structure stability.  

Czech Academy of Sciences Publication Activity Database

Ro?. 8, - (2006). ISSN 1029-7006. [EGU General Assembly 2006. 02.04.2006-07.04.2006, Vienna] Institutional research plan: CEZ:AV0Z30130516 Keywords : soil micromorphology * soil porous system * soil hydraulic Subject RIV: DF - Soil Science http://www.cosis.net/abstracts/EGU06/10474/EGU06-J-10474-5.pdf

Kodešová, R.; Žigová, Anna; Rohošková, M.; Kodeš, V.; Kutílek, M.

2006-01-01

333

Hierarchial Control of Hydraulic Active Suspensions of a Fast All-Terrain Military Vehicle  

Science.gov (United States)

This paper describes a procedure to improve the behavior of a light all-terrain military vehicle moving, over rough ground and large obstacles, at high speed. This improvement has governed the choice of a new concept of hydraulic active-passive linking between the body and the ground. A hierarchical control strategy is then proposed which divides the management of vehicle dynamics into two levels: a central control which takes into account the pitch and the gap between the body and the ground and delivers orders to local independent controls devoted to each active suspension and bogie assembly. In this case, the feasibility of this control can be validated on a quarter vehicle moving only in the vertical direction. The local controller uses a classical P.I.D. and the central control implemented uses a Linear Quadratic Gaussian which is suited to the specific purposes of the control. A scale model of a quarter vehicle is used to validate this process. Simulation and experimental results are in good agreement and show the improvement of capacities for crossing large obstacles at speed.

Der Hagopian, J.; Gaudiller, L.; Maillard, B.

1999-05-01

334

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.

335

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)

336

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.

337

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 selectin...

Virgílio José Martins Ferreira Filho; Antônio Orestes de Salvo Castro

2014-01-01

338

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

339

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

340

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

341

Hydraulic conductivity, specific yield, and pumpage--High Plains aquifer system, Nebraska  

Science.gov (United States)

Hydrologic data used to evalute the ground-water potential of the High Plains aquifer system in Nebraska are presented on maps showing the hydraulic conductivity and specific yield of the aquifer system and the volume and distribution of water pumped for irrigation from the aquifer system during 1980. The High Plains aquifer system underlies 177,000 square miles in parts of eight states, including 64,770 square miles in Nebraska. It consists of the Ogallala Formation and Tertiary and Quaternary deposits that are saturated and hydraulically connected to the Ogallala. The hydraulic conductivity of the aquifer system varies from greater than 200 feet per day in parts of the North Platte, Platte, Elkhorn, and Republican River valleys to less than 25 feet per day in the northwestern part of the state. Specific yield of the aquifer system ranges from 10 to 20 percent in most of the state and averages 16 percent. The estimated volume of water recoverable from the aquifer system in Nebraska is 2,237 million acre-feet. Inches of water withdrawn from the aquifer system during 1980 varied from less than 1.5 in the sandhills of north-central Nebraska to more than 12 in the Platte River and Blue River basins. This withdrawal represents about 6,703,000 acre-feet of ground water. (USGS)

Pettijohn, Robert A.; Chen, Hsiu-Hsiung

1983-01-01

342

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

343

Control system design method  

Science.gov (United States)

A control system design method and concomitant control system comprising representing a physical apparatus to be controlled as a Hamiltonian system, determining elements of the Hamiltonian system representation which are power generators, power dissipators, and power storage devices, analyzing stability and performance of the Hamiltonian system based on the results of the determining step and determining necessary and sufficient conditions for stability of the Hamiltonian system, creating a stable control system based on the results of the analyzing step, and employing the resulting control system to control the physical apparatus.

Wilson, David G. (Tijeras, NM); Robinett, III, Rush D. (Tijeras, NM)

2012-02-21

344

GCFR plant control system  

Energy Technology Data Exchange (ETDEWEB)

A plant control system is being designed for a gas-cooled fast breeder reactor (GCFR) demonstration plant. Control analysis is being performed as an integral part of the plant design process to ensure that control requirements are satisfied as the plant design evolves. The load control portion of the plant control system provides stable automatic (closed-loop) control of the plant over the 25% to 100% load range. Simulation results are presented to demonstrate load control system performance. The results show that the plant is controllable at full load with the control system structure selected, but gain scheduling is required to achieve desired performance over the load range.

Estrine, E.A.; Greiner, H.G.

1980-05-01

345

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

346

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

347

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

348

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

349

Thermal-Hydraulic System Codes in Nuclear Reactor Safety and Qualification Procedures  

International Nuclear Information System (INIS)

In the last four decades, large efforts have been undertaken to provide reliable thermal-hydraulic system codes for the analyses of transients and accidents in nuclear power plants. Whereas the first system codes, developed at the beginning of the 1970s, utilized the homogenous equilibrium model with three balance equations to describe the two-phase flow, nowadays the more advanced system codes are based on the so-called two-fluid model with separation of the water and vapor phases, resulting in systems with at least six balance equations. The wide experimental campaign, constituted by the integral and separate effect tests, conducted under the umbrella of the OECD/CSNI was at the basis of the development and validation of the thermal-hydraulic system codes by which they have reached the present high degree of maturity. However, notwithstanding the huge amounts of financial and human resources invested, the results predicted by the code are still affected by errors whose origins can be attributed to several reasons as model deficiencies, approximations in the numerical solution, nodalization effects, and imperfect knowledge of boundary and initial conditions. In this context, the existence of qualified procedures for a consistent application of qualified thermal-hydraulic system code is necessary and implies the drawing up of specific criteria through which the code-user, the nodalization, and finally the transient results are qualified qualified

350

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.

351

Hydraulic Conductivity Estimation Test Impact on Long-Term Acceptance Rate and Soil Absorption System Design  

Directory of Open Access Journals (Sweden)

Full Text Available The aim of this paper was to verify the common methods of hydraulic conductivity estimation for soil assessment in respect to wastewater disposal. The studies were conducted on three types of sandy soils. Hydraulic conductivity was determined using a scale effect-free laboratory method, empirical equations and compared with measurements estimated from a laboratory infiltration column with identified head loss. Based on the hydraulic conductivity values, the long-term acceptance rates (LTAR [1] were calculated. The differences in LTAR values were about one order of magnitude smaller than differences in hydraulic coefficient. The study showed a good convergention of the results obtained from the constant head method (CHM by solving the Glover Equation for medium and coarse sands. In low permeability soil (fine sand, the best result was obtained using CHM-a with a capillary rise consideration (a is a factor included in the flow in the unsaturated and saturated zones calculated from a capillary rise. From a practical point of view the relatively small value of LTAR underestimation (20%-for constant head method is responsible for the extended surface area of the system and provides a security margin (the avoidance of clogging risk. The use of the falling head method, based on the Van Hoorn equation, can be said to be highly overestimated. For medium and coarse sandy soils the underestimation of LTAR calculated and based on CHM test determination is 14%–18%. The total cost of soil absorption system (SAS designed-based on CHM in comparison to that designed-based on real hydraulic conductivity value in Poland is only about 7%–9% higher.

Jakub Nie?

2014-09-01

352

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.

353

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

354

SCADA of an Upstream Controlled Irrigation Canal System  

OpenAIRE

Upstream control in canals is efficient only when associated with rigid water delivery methods. In Portugal, all of the upstream controlled systems work with flexible water delivery schedules and, for this reason, operational water losses become significant. Because there is no storage reserve inside this kind of systems it is necessary to take into account the demand prediction or the command anticipation of the hydraulic control devices in order to improve the system response to demand vari...

Rijo, Manuel

1999-01-01

355

Nuclear reactor plants and control systems therefor  

International Nuclear Information System (INIS)

A nuclear reactor plant is described comprising at least two hydraulically separated but thermally interconnected heat conveying circuits, of which one is the reactor circuit filled with a non-water medium and the other one is the water-steam-circuit equipped with a steam generator, a feed water conduit controlled by a valve and a steam turbine, and a control system mainly influenced by the pressure drop caused in said feed water conduit and its control valve and having a value of at least 10 bars at full load

356

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

357

Beneficial effects on water management of simple hydraulic structures in wetland systems: the Vallevecchia case study, Italy.  

Science.gov (United States)

Conflicting water uses in coastal zones demand integrated approaches to achieve sustainable water resources management, protecting water quality while allowing those human activities which rely upon aquatic ecosystem services to thrive. This case study shows that the creation and simple management of hydraulic structures within constructed wetlands can markedly reduce the non-point pollution from agriculture and, simultaneously, benefit agricultural activities, particularly during hot and dry periods. The Vallevecchia wetland system is based on a reclaimed 900 ha-large drainage basin in Northern Italy, where droughts recently impacted agriculture causing water scarcity and saltwater intrusion. Rainwater and drained water are recirculated inside the system to limit saltwater intrusion, provide irrigation water during dry periods and reduce the agricultural nutrient loads discharged into the bordering, eutrophic Adriatic Sea. Monitoring (2003-2009) of water quality and flows highlights that the construction (ended in 2005) of a gated spillway to control the outflow, and of a 200,000 m3 basin for water storage, dramatically increased the removal of nutrients within the system. Strikingly, this improvement was achieved with a minimal management effort, e.g., each year the storage basin was filled once: a simple management of the hydraulic structures would greatly enhance the system efficiency, and store more water to irrigate and limit saltwater intrusion. PMID:22053478

Carrer, G M; Bonato, M; Smania, D; Barausse, A; Comis, C; Palmeri, L

2011-01-01

358

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

359

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

Science.gov (United States)

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.

Maharjan, M.; Pathirana, A.; Gersonius, B.; Vairavamoorthy, K.

2009-04-01

360

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

361

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

362

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.

363

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

364

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)

365

Neutronic and thermal hydraulic of dry cask storage systems  

International Nuclear Information System (INIS)

Interim spent fuel storage systems must provide for the safe receipt, handling, retrieval and storage of spent nuclear fuel before reprocessing or disposal. In the context of achieving these objectives, the following features of the design are to be taken into consideration: to maintain fuel subcritical, to remove spent fuel residualheat, and to provide for radiation protection. These features in the design of a dry cask storage system were analyzed for normal operating conditions by employing COBRA-SFS, SCALE4.4 (ORIGEN, XSDOSE, CSAS6) codes. For a metal-shielded type storage system, appropriate designs, in accordance with safety assurance limits of IAEA, were obtained for spent fuel burned to 33000, 45000 and 55000 MW d/t and cooled for 5 and 10 years

366

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

367

Development of CFD Analysis Methodology of Hydraulic Load Evaluation in POSRV Piping System  

International Nuclear Information System (INIS)

APR1400 has been improved as an advanced light water reactor that adopts new technology's. One of major technologies is IRWST(In-containment Refueling Water Storage Tank) placed inside containment. In order to adjust the new technology when POSRV(Pilot Operated Safety Relief Valve) is opened, POSRV-IRWST linked line must be kept safe. Theoretical solution and experimental data are needed for structure integrity, but proven data are insufficient from the viewpoint of hydrodynamics. The hydrodynamic flow analysis and the thermodynamic behavior analysis should be performed by using CFD. The objective of this study is to develop the CFD analysis methodology of hydraulic load evaluation in IRWST piping system. This method is a basic hydraulic load evaluation in POSRV piping system. Also, this will help to analyze fluid-structural interface and to predict special phenomena. Therefore, that can be used as a basis to the most suitable design

368

EXPERIMENTAL SYSTEM FOR INVESTIGATION OF CAVITATION PHENOMENA IN HYDRAULIC SHOCK ABSORBERS.  

Czech Academy of Sciences Publication Activity Database

Liberec : Technical University of Liberec, 2009 - (Vít, T.; Dan?ová, P.; Dvo?ák, V.), s. 224-229 ISBN 978-80-7372-538-9. [International Conference Experimental Fluid Mechanics 2009. Liberec (CZ), 25.11.2009-27.11.2009] R&D Projects: GA ?R(CZ) GA101/07/1612 Institutional research plan: CEZ:AV0Z20760514 Keywords : cavitation * hydraulic shock absorber * experimental system Subject RIV: BK - Fluid Dynamics

Müller, M.; Prášil, L.; Zima, Patrik

369

How to effectively compute the reliability of a thermal-hydraulic nuclear passive system  

OpenAIRE

The computation of the reliability of a thermal-hydraulic (T-H) passive system of a nuclear power plant can be obtained by (i) Monte Carlo (MC) sampling the uncertainties of the system model and parameters, (ii) computing, for each sample, the system response by a mechanistic T-H code and (iii) comparing the system response with pre-established safety thresholds, which define the success or failure of the safety function. The computational effort involved can be prohibitive because of the lar...

Zio, Enrico; Pedroni, Nicola

2011-01-01

370

Simulation Research on an Electric Vehicle Chassis System Based on a Collaborative Control System  

OpenAIRE

This paper presents a collaborative control system for an electric vehicle chassis based on a centralized and hierarchical control architecture. The centralized controller was designed for the suspension and steering system, which is used for improving ride comfort and handling stability; the hierarchical controller was designed for the braking system, which is used for distributing the proportion of hydraulic braking and regenerative braking to improve braking performance. These two sub-cont...

Nenglian Feng; Hongwen He; Jiankun Peng

2013-01-01

371

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

372

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

373

Neutronics and thermal hydraulics coupling scheme for design improvement of liquid metal fast systems  

International Nuclear Information System (INIS)

Many advanced reactor concepts are nowadays under investigations within the Generation IV international initiative as well as in European research programs including subcritical and critical fast reactor systems cooled by liquid metal, gas and supercritical water. The Institute of Neutron Physics and Reactor Technology (INR) at the Forschungszentrum Karlsruhe GmbH is involved in different European projects like IP EUROTRANS, ELSY, ESFR. The main goal of these projects is, among others, to assess the technical feasibility of proposed concepts regarding safety, economics and transmutation requirements. In view of increased computer capabilities, improved computational schemes, where the neutronic and the thermal hydraulic solution is iteratively coupled, become practicable. The codes ERANOS2.1 and TRACE are being coupled to analyze fuel assembly or core designs of lead-cooled fast reactors (LFR). The neutronic solution obtained with the coupled system for a LFR fuel assembly was compared with the MCNP5 solution. It was shown that the coupled system is predicting physically sound results. The iterative coupling scheme was realized using Perlscripts and auxiliary Fortran programs to ensure that the mapping between the neutronic and the thermal hydraulic part is consistent. The coupled scheme is very flexible and appropriate for the neutron physical and thermal hydraulic investigation of fuel assemblies and of cores of lead cooled fast reactors. The developed methods and tfast reactors. The developed methods and the obtained results will be presented and discussed. (author)

374

Thermal-Hydraulic Feedback Module for BGCore System  

International Nuclear Information System (INIS)

The need for accurate fuel management modeling in Generation IV (LFR, HTGR, etc) reactors has motivated the development of a new and comprehensive code (the BGCore system) for core analysis of advanced reactors. This effort is justified since there are currently no high fidelity codes, which are capable of performing for different types of advanced reactors calculations. Reliable modeling of the core performance requires an adequate modeling of a wide range of physical processes, such as fuel depletion and the temperature distribution in the main core components

375

Integrated methodology to correlate the fuel injection system's hydraulic performance with the emissions and indicated output of a common rail Diesel engine  

Energy Technology Data Exchange (ETDEWEB)

A new integrated methodology was developed to describe the performances of a Common Rail Fuel Injection System (F.I.S.) for modern D.I. Diesel engine, with focus on the temporal actuation of the injection. The temporal injection performance (injection rate) of a Diesel F.I.S. was described with quantitative indicators and correlated with the engine results of dedicated experiments. Different hydraulic parameters, representative of the injection rate control, were defined and for each a target value was associated with relative acceptable tolerances. The F.I.S. capability to guarantee a consistent injection rate control was expressed in terms of stability (shot to shot repeatability), disturbances sensitivity and production dispersions. In support of the experimental campaign a ''0 dimensional'' numerical code was applied to simulate the dynamic F.I.S. hydraulic response with focus on the injection rate control. After an adequate tuning and validation phase, the numerical model was applied for the optimization of the high pressure circuit layout: the experimental campaign showed the relevant impact of this layout on the injection rate control. Quantitative specifications for the injection rate control were defined with this methodology, in coherence with the combustion system response to the temporal hydraulic characteristics. (orig.)

Canale, S.; D' Amato, D.D.; De Paola, G.; Pelassa, M. [Centro Ricerche Fiat - Orbassano (Italy)

2004-07-01

376

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

377

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)

378

Skylab attitude control system  

Science.gov (United States)

The attitude stabilization and control system for Skylab evolved from an analog controller into a fully digital processing system. Features of this system include a software-determined attitude reference to provide general maneuvering ability, an in-orbit programming capability, the use of large control moment gyros for attitude control, and the use of vehicle maneuvers to desaturate gyro momentum. The objectives, requirements, and implementations of the control system software are described, along with the rationales for certain design decisions and discussion of some system dynamics and actual performance.

Coon, T. R.; Irby, J. E.

1976-01-01

379

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

380

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

381

Development and verification of the MASTER dynamic link library (DLL) for integration into a system thermal-hydraulics code  

International Nuclear Information System (INIS)

The dynamic link library (DLL) of the MASTER code has been generated and verified for the use in code coupling to build an integrated nuclear power plant transient analysis code by combining the three-dimensional neutron kinetic code with a system thermal-hydraulic code. For the generation of the MASTER DLL, the link variables needed for incorporating thermal feedback effects were identified first and a data exchange scheme was established. The MASTER code was modified such that it can run on the Windows operating system and a couple of newly written link subroutines were added to generate the DLL. For the standalone verification of the DLL, a coupled code was built by using a simple thermal-hydraulic code and the DLL and the coupled code was applied to the NEACRP benchmark problems, which offer a variety of steady state and control rod ejection calculations. The verification was done by comparing the results of the coupled code calculations were compared with corresponding MASTER standalone calculations. In addition, a set of sensitivity studies were performed to check the sound operation of the neutronic /T-H calculations. It was made sure based on these verifications that the generated MASTER DLL is sound and work properly. (author). 5 refs., 7 tabs., 14 figs

382

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

383

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

384

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)

385

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

386

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

387

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

388

Four models of bioclogging describing anisotropy of hydraulic conductivity in one dimensional flow system  

Science.gov (United States)

Anisotropy of hydraulic conductivity of clogged porous media in one dimensional flow system was analysed by four models, and applicability of these models are compared and discussed. The anisotropy of hydraulic conductivity is observed when nutrient solution is supplied from top of experimental column. In such a column, thin clogged layer is formed at the inlet of the column, and the average hydraulic conductivity in two directions of the whole column differs. When the flow is in the vertical direction, the hydraulic conductivity is small in the vertical direction but not so small in the horizontal direction. The column is clogged along the flow direction, but not clogged along another direction. The first model, microscopic anisotropy model, assumes that the saturated hydraulic conductivity of clogged layer has anisotropy. This microscopic anisotropy is explained by the distribution of microbial colonies on the particles of porous media. The microbial cells clog to the flow direction (vertical direction), but it does not clog the pathway of water in the horizontal direction. The second model, two layer model, assumes that the clogged column has two layers; thin clogged layer at the inlet of nutrient solution and unclogged layer at the rest of the column. The third model, three layer model, assumes that the clogged column has three layers; a very thin severely clogged layer at the inlet (usually a few milimeters), a thin moderately clogged layer just beneath the previous layer (about 1 centimeters), and unclogged layer at the rest of the column. The forth model, clogging coefficient model, describes bioclogging by newly introduced variable, clogging coefficient. By assuming two layer model, the clogging coefficient is the hydraulic conductivity of clogged layer devided by the thickness of the clogged layer, and it has the dimension of time inverse. By applying these four models to the result of a column experiment, we found that the microscopical anisotropy in the first model is not important when clogged layer is formed, because most of the flow in the horizontal direction flow in the unclogged layer. The second model, two layer model, is good in some case but provides unrealistic result in another case. The third model is a fairy reasonable model, but it has the demerit that the thickness of the clogged layer cannot be determined precisely. The forth model, the most recommended model, proved to be a convenient tool for the analysis in bioclogging phenomenum.

Seki, K.; Hanada, J.; Miyazaki, T.

2002-05-01

389

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

390

Fabrication and test of hydraulic jacks for the application to divertor support system of fusion experimental reactor  

International Nuclear Information System (INIS)

This paper reports on two different types of hydraulic jacks consisting of hydraulic piston and bellows which were developed for an application to locking and lifting systems for divertor segments for Fusion Experimental Reactor. For the lifting system where a minimum stroke of 170 mm was required, the telescopic-type hydraulic jack with a length of 300 mm was fabricated and tested under an operation pressure of 1 MPa. for the locking system, the hydraulic jack with the conical cotter was developed that worked at 6.5 MPa under a radial offset of 2 mm. These jacks satisffied their specifications without any leakage, failure and abrasion. Performance of several hard facing materials for the cotter was also examined including alumina and metal alloys. The colmony no. 5 or stellite alloy no. 6 was found to be excellent as a hard facing material for the cotter

391

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)

392

Fish pass assessment by remote control: a novel framework for quantifying the hydraulics at fish pass entrances  

Science.gov (United States)

Fragmentation of aquatic habitats can lead to the extinction of migratory fish species with severe negative consequences at the ecosystem level and thus opposes the target of good ecological status of rivers defined in the EU Water Framework Directive (WFD). In the UK, the implementation of the EU WFD requires investments in fish pass facilities of estimated 532 million GBP (i.e. 639 million Euros) until 2027 to ensure fish passage at around 3,000 barriers considered critical. Hundreds of passes have been installed in the past. However, monitoring studies of fish passes around the world indicate that on average less than half of the fish attempting to pass such facilities are actually successful. There is a need for frameworks that allow the rapid identification of facilities that are biologically effective and those that require enhancement. Although there are many environmental characteristics that can affect fish passage success, past research suggests that variations in hydrodynamic conditions, reflected in water velocities, velocity gradients and turbulences, are the major cues that fish use to seek migration pathways in rivers. This paper presents the first steps taken in the development of a framework for the rapid field-based quantification of the hydraulic conditions downstream of fish passes and the assessment of the attractivity of fish passes for salmonids and coarse fish in UK rivers. For this purpose, a small-sized remote control platform carrying an acoustic Doppler current profiler (ADCP), a GPS unit, a stereo camera and an inertial measurement unit has been developed. The large amount of data on water velocities and depths measured by the ADCP within relatively short time is used to quantify the spatial and temporal distribution of water velocities. By matching these hydraulic features with known preferences of migratory fish, it is attempted to identify likely migration routes and aggregation areas at barriers as well as hydraulic features that may distract fish away from fish pass entrances. The initial steps of the framework development have focused on the challenge of precise spatial data referencing in areas with limited sky view to navigation satellites. Platform tracking with a motorised Total Station, various satellite-based positioning solutions and simultaneous localisation and mapping (SLAM) based on stereo images have been tested. The effect of errors in spatial data referencing on ADCP-derived maps of flow features and bathymetry will be quantified through simultaneous deployment of these navigation technologies and the ADCP. This will inform the selection of a cost-effective platform positioning system in practice. Further steps will cover the quantification of uncertainties in ADCP data caused by highly turbulent flows and the identification of suitable ADCP data sampling strategies at fish passes. The final framework for fish pass assessment can contribute to an improved understanding of the interaction of fish and the complex hydraulic river environment.

Kriechbaumer, Thomas; Blackburn, Kim; Gill, Andrew; Breckon, Toby; Everard, Nick; Wright, Ros; Rivas Casado, Monica

2014-05-01

393

The coupled neutronics and thermal hydraulics code system PANBOX for PWR safety analysis  

Energy Technology Data Exchange (ETDEWEB)

PANBOX is used for reload safety analysis and all kinds of transients in which the power distribution is significantly affected. Apart from input and output processors it consists of dedicated modules which treat specific transients such as long-term events like xenon redistribution and short-term accidents like rod ejections. Theory, application and verification of the system are described. The global solution is combined with an accurate and efficient pin power reconstruction module. Thus the system is capable of performing global neutronic/thermal-hydraulic calculations and of evaluating important safety-related parameters, such as departure from nucleate boiling ratios and centreline fuel temperatures. (orig./HP).

Boeer, R.; Boehm, R.; Finnemann, H.; Mueller, R. (Siemens AG, KWU, Erlangen (Germany). Bereich Energieerzeugung)

1992-02-01

394

The coupled neutronics and thermal hydraulics code system PANBOX for PWR safety analysis  

International Nuclear Information System (INIS)

PANBOX is used for reload safety analysis and all kinds of transients in which the power distribution is significantly affected. Apart from input and output processors it consists of dedicated modules which treat specific transients such as long-term events like xenon redistribution and short-term accidents like rod ejections. Theory, application and verification of the system are described. The global solution is combined with an accurate and efficient pin power reconstruction module. Thus the system is capable of performing global neutronic/thermal-hydraulic calculations and of evaluating important safety-related parameters, such as departure from nucleate boiling ratios and centreline fuel temperatures. (orig./HP)

395

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

396

Control rod drive water supply system  

International Nuclear Information System (INIS)

Purpose: To prevent atmospheric corrosion within a reactor container of a control rod drive hydraulic system which is closely disposed and hard to repair from outside. Constitution: In a BWR type nuclear power plant, drive water which is supplied to hydraulically driven control rod drives is taken from a condensate feedwater system. That is, the drive water is supplied from a control rod drive water intake line connected to a water supply port of a condensate desalting equipment and from a branch line of a water supply line of a feedwater heater, thereby raising a drive water temperature and lowering the relative humidity of the atmosphere in the vicinity of the piping surface, to prevent the occurrence of SCC of the piping by the atmospheric corrosion. Since the drive water is taken from the Low-Dissolved oxygen system water of the nuclear power plant, there is very little possibility of water entrance into the reactor. Furthermore, low construction cost and plant maintenance cost as well as a simplified system can be realized without installing a heater to the drive water pressure system. (Kawakami, Y.)

397

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

398

ALFA Detector Control System  

CERN Document Server

ALFA (Absolute Luminosity For ATLAS) is one of the sub-detectors of ATLAS (A Toroidal LHC Apparatus). The ALFA system is composed by four stations installed in the LHC tunnel 240 m away from the ATLAS interaction point. Each station has a vacuum and ventilation system, movement control and all the required electronics 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

399

A field study of hydraulic, geochemical and stable isotope relationships in a coastal wetlands system  

Science.gov (United States)

Both chemical and stable isotope data provide important supplemental information to more traditional hydraulic data and unravel the processes that underpin the large variations in chemical and stable isotopic composition within a coastal wetland system. The system studied was the Lake Warden wetlands, located in Esperance, in south coast of Western Australia. The spatial and temporal variations of chemical and isotopic composition of the individual water bodies within the system were measured for an annual cycle. In broad terms, the groundwater levels appear to follow the topography but the distinct higher chloride and isotopic concentrations observed within the wetlands were not reflected in the low lying coastal plain groundwater. The hydraulic analysis of the region surrounding the wetlands suggest that the wetlands are flow-through bodies, however the chemical and isotope information indicates the lakes almost invariably act as discharge points for the surface water flows and the north-south groundwater flow. The northeast-southwest groundwater flow is along an observed paleochannel within the wetlands system and in this case the chemical and isotopic evidence are complimentary with the hydraulic study. The study highlighted the importance of correcting the isotopic values for the salt effect in highly saline water. The isotopic activity ratios of ?2H ( ?2H a) of some samples were up to 15‰ higher than the uncorrected values. The high salinity of the terminal lake in the wetlands chain also required implementation of a theoretical evaporative model to explain the lower enrichment of the isotopic results as compared to expectations for a shallow and ephemeral lake. The inter-lake variation in the theoretical evaporative model parameters, coupled with a significant variation in the hydrochemistry and isotope composition suggests that the lakes within the wetlands system cannot be treated as single water body as is implied by the bathymetry survey.

Marimuthu, S.; Reynolds, D. A.; La Salle, C. Le Gal

2005-12-01

400

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

401

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

402

Motion control systems  

CERN Document Server

"Presents a unified approach to the fundamental issues in motion control, starting from the basics and moving through single degree of freedom and multi-degree of freedom systems In Motion Control Systems, S?abanovic and Ohnishi present a unified approach to very diverse issues covered in motion control systems, offering know-how accumulated through work on very diverse problems into a comprehensive, integrated approach suitable for application in high demanding high-tech products. It covers material from single degree of freedom systems to complex multi-body non-redundant and redundant systems. The discussion of the main subject is based on original research results and will give treatment of the issues in motion control in the framework of the acceleration control method with disturbance rejection technique. This allows consistent unification of different issues in motion control ranging from simple trajectory tracking to topics related to haptics and bilateral control without and with delay in the measure...

Sabanovic, Asif

2011-01-01

403

Neural daylight control system  

OpenAIRE

The paper describes the design, the implementation of a neural controller used in an automatic daylight control system. The automatic lighting control system (ALCS) attempt to maintain constant the illuminance at the desired level on working plane even if the daylight contribution is variable. Therefore, the daylight will represent the perturbation signal for the ALCS. The mathematical model of process is unknown. The applied structure of control need the inverse model of pr...

Grif, Horatiu Stefan

2010-01-01

404

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

405

Gas well de-watering system and hydraulic gas pump, new designs and a discussion on their economics  

Energy Technology Data Exchange (ETDEWEB)

The concepts for two new artificial lift systems were first presented in SPE paper 25422. In the present paper improved designs are presented. The application and the economics of the Hydraulic Gas Pump are compared to the gas lift method that was used in East Quito Fusselman Reservoir, Ward County, Texas. The author concludes that the Hydraulic Gas Pump can be a more economic artificial lift method than gas lift for East Quito Fusselman Reservoir.

Amani, M. [Texas A and M Univ., College Station, TX (United States)

1994-12-31

406

Thermal-hydraulic design concept of the N-Arena solid-target system in JHF project. Heat transfer experiment  

International Nuclear Information System (INIS)

In relation to thermal-hydraulic design of the N-Arena solid-target system of the Japan Hadron Facility (JHF) project, heat transfer experiments were performed to obtain experimental data systematically on heat transfer coefficient and critical heat flux for vertical upward and horizontal flows in a thin rectangular channel simulating a coolant channel of the proposed spallation neutron source. Thermal-hydraulic correlations which can be used for design calculations were proposed based on the obtained data. (author)

407

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

Energy Technology Data Exchange (ETDEWEB)

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)

Parisi, C.; D' Auria, F. [Univ. of Pisa, Dept. of Mechanical, Nuclear and Production Engineering, via Diotisalvi, 2, 56100 Pisa (Italy); Malofeev, V. [Kurchatov Inst., Kurchatov Square 1, Moscow 123182 (Russian Federation); Ivanov, B.; Ivanov, K. [Pennsylvania State Univ., RDFMG, 230 Reber Building, Univ. Park, PA 16802 (United States)

2006-07-01

408