WorldWideScience

Sample records for hydraulic control systems

  1. Modular hydraulic control system

    Science.gov (United States)

    Winyard, David C.; Lindstrom, Waldemar C.

    1994-06-01

    A system of modular electrohydraulic servovalves is centrally controlled and may be used to control the operation of critical hydraulic actuators. A programmable controller operates a group of modular servovalves which each deliver a portion of the total actuator fluid requirements. The flow rate, valve position, and valve pressure of each servovalve is monitored by the controller and compared to expected values in memory to determine whether a servovalve malfunction exists. If so, the controller maintains the required flow rate to the actuator by closing the malfunctioning valve and either activating a spare or proportionally increasing the flow rates of the remaining servovalves to compensate for the loss.

  2. 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

  3. Control rod drive hydraulic system

    Science.gov (United States)

    Ose, Richard A. (San Jose, CA)

    1992-01-01

    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.

  4. Hydraulic loop: practices using open control systems

    International Nuclear Information System (INIS)

    The Tecnatom Hydraulic Loop is a dynamic training platform. It has been designed with the purpose of improving the work in teams. With this system, the student can obtain a full scope vision of a system. The hydraulic Loop is a part of the Tecnatom Maintenance Centre. The first objective of the hydraulic Loop is the instruction in components, process and process control using open control system. All the personal of an electric power plant can be trained in the Hydraulic Loop with specific courses. The development of a dynamic tool for tests previous to plant installations has been an additional objective of the Hydraulic Loop. The use of this platform is complementary to the use of full-scope simulators in order to debug and to analyse advanced control strategies. (Author)

  5. Towards Autonomous Control of Hydraulic Actuator Systems

    DEFF Research Database (Denmark)

    Hansen, Poul Erik; Conrad, Finn

    1998-01-01

    Presentation of new developed control algorithms to increase autonomy and intelligence of hydraulic control systems. A refinement of relaytuning method is used to determine the control parameters of a lag/lead controller and a poleplacement controller. Further, a fail-safe function is developed to hinder surges and mechanical fractures. Experimental results verify the performance of the controllers.

  6. Highly reliable electro-hydraulic control system

    International Nuclear Information System (INIS)

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

  7. Connection of hydraulic flow control system

    International Nuclear Information System (INIS)

    The connection is described of a hydraulic system controling the coolant flow through the assembly of a nuclear reactor. To the hydraulically controlled control device are connected the two branches of the hydraulic system, the filling branch being connected to the primary circuit of the reactor by an open electromagnetic valve and the working branch containing the pressure source of the working liquid being connected to the drainage by a closed electromagnetic valve. A filter may be placed in the filling branch and a pressure gauge in the working branch. The two branches may be connected with a clamp with a stop valve between the control equipment and the electromagnetic valves. Also, the working branch may be linked via a safety valve with the filling branch, this between the control device and the closed electromagnetic valve and between the primary circuit and the open electromagnetic Valve. (B.S.)

  8. Hydraulic Actuator System for Rotor Control

    Science.gov (United States)

    Ulbrich, Heinz; Althaus, Josef

    1991-01-01

    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.

  9. 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

  10. Hydraulic system for driving control rod

    International Nuclear Information System (INIS)

    Purpose: To protect a control rod drive hydraulic system from corrosion and stress corrosion cracking by recirculating in the system the filtrate which has been treated in a coolant cleanup system to bring dissolved oxygen content within certain limits. Constitution: The coolant for a pressure vessel is passed through a coolant cleanup system, regenerative heat exchanger, and nonregenerative heat exchanger to be cooled down to about 500C. Then it is cleaned by a filtrator-desalter, heated again by the regenerative heat exchanger, fed into feed water line, and returned to the pressure vessel. The input line of the control rod drive hydraulic system is connected on the rear of the filtrator-desalter. Part of the coolant having controlled dissolved oxygen content is used in the hydraulic system as filling water, driving water, and cooling water. The reactor return line is connected on the front of the secondary side of the regenerative heat exchanger, so as to relieve the thermal stress applied to the pressure vessel. (Nakamura, S.)

  11. A low order adaptive control scheme for hydraulic servo systems

    DEFF Research Database (Denmark)

    Andersen, Torben Ole; Pedersen, Henrik Clemmensen; Bech, Michael Mřller; Schmidt, Lasse

    2015-01-01

    This paper deals with high-performance position control of hydraulics servo systems in general. The hydraulic servo system used is a two link robotic manipulator actuated by two hydraulic servo cylinders. A non-linear model of the hydraulic system and a Newton-Euler based model of the mechanical system were constructed and linearized. Controllers are implemented and tested on the manipulator. Pressure feedback was found to greatly improve system stability margins. Passive gain feedforward shows ...

  12. Study on Characteristics of Hydraulic Servo System for Force Control of Hydraulic Robots

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyo-gon; Han, Changsoo [Hanyang University, Seoul (Korea, Republic of); Lee, Jong-won [Korea University of Science and Technology, Seoul (Korea, Republic of); Park, Sangdeok [Korea Institute of Industrial Technology, Seoul (Korea, Republic of)

    2015-02-15

    Because a hydraulic actuator has high power and force densities, this allows the weight of the robot's limbs to be reduced. This allows for good dynamic characteristics and high energy efficiency. Thus, hydraulic actuators are used in some exoskeleton robots and quadrupedal robots that require high torque. Force control is useful for robot compliance with a user or environment. However, force control of a hydraulic robot is difficult because a hydraulic servo system is highly nonlinear from a control perspective. In this study, a nonlinear model was used to develop a simulation program for a hydraulic servo system consisting of a servo valve, transmission lines, and a cylinder. The problems and considerations with regard to the force control performance for a hydraulic servo system were investigated. A force control method using the nonlinear model was proposed, and its effect was evaluated with the simulation program.

  13. Study on Characteristics of Hydraulic Servo System for Force Control of Hydraulic Robots

    International Nuclear Information System (INIS)

    Because a hydraulic actuator has high power and force densities, this allows the weight of the robot's limbs to be reduced. This allows for good dynamic characteristics and high energy efficiency. Thus, hydraulic actuators are used in some exoskeleton robots and quadrupedal robots that require high torque. Force control is useful for robot compliance with a user or environment. However, force control of a hydraulic robot is difficult because a hydraulic servo system is highly nonlinear from a control perspective. In this study, a nonlinear model was used to develop a simulation program for a hydraulic servo system consisting of a servo valve, transmission lines, and a cylinder. The problems and considerations with regard to the force control performance for a hydraulic servo system were investigated. A force control method using the nonlinear model was proposed, and its effect was evaluated with the simulation program

  14. Hydraulic system for driving control rods

    International Nuclear Information System (INIS)

    Purpose: To enable safety reactor shut down upon occurrence of an abnormal excess pressure in a hydraulic control unit. Constitution: The actuation pressure for a pressure switch that generates a scram signal is set lower than the release pressure set to a pressure release valve. Thus, if the pressure of nitrogen gas in a nitrogen container increases such as upon exposure of the hydraulic control unit to a high temperature, the pressure switch is actuated at first to generate the scram signal and a scram valve is opened to supply water at high pressure to control rod drives under the driving force of the nitrogen gas at high pressure to rapidly insert the control element into the reactor and shut down it. If the pressure of the nitrogen gas still increases after the scram, the pressure release valve is opened to release the nitrogen gas at high temperature to the atmosphere. Since the scram is attained before the actuation of the pressure release valve, safety reactor shut down can be attained and the hydraulic control unit can be protected. (Sekiya, K.)

  15. Pressure Control in Hydraulic Power Steering Systems

    OpenAIRE

    Dell’Amico, Alessandro

    2013-01-01

    There is a clear trend in the vehicle industry to implement more safetyrelated functions, where the focus is on active safety systems and today the steering system is also involved. Steering-related active safety functions can only be realised with a steering system that allows electroniccontrol of either the road wheel angle or the torque required to steer the vehicle, called active steering. The high power requirement of heavy vehicles means they must rely on hydraulic power to assist the d...

  16. Adaptive Non-linear Control of Hydraulic Actuator Systems

    DEFF Research Database (Denmark)

    Hansen, Poul Erik; Conrad, Finn

    1998-01-01

    Presentation of two new developed adaptive non-liner controllers for hydraulic actuator systems to give stable operation and improved performance.Results from the IMCIA project supported by the Danish Technical Research Council (STVF).

  17. Flow versus pressure control of pumps in mobile hydraulic systems

    OpenAIRE

    Axin, Mikael; Eriksson, Björn; Krus, Petter

    2014-01-01

    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, lo...

  18. Control Reconfigurability of Bilinear Hydraulic Drive Systems

    DEFF Research Database (Denmark)

    Shaker, Hamid Reza; Tahavori, Maryamsadat

    2011-01-01

    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 ...

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

    DEFF Research Database (Denmark)

    Choux, Martin

    2011-01-01

    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 increasingl...

  20. Hydraulic engine valve actuation system including independent feedback control

    Science.gov (United States)

    Marriott, Craig D

    2013-06-04

    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.

  1. 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

  2. Inspection operation aid device and method for control rod drives and hydraulic control system

    International Nuclear Information System (INIS)

    The device of the present invention comprises an input/output device for inputting/outputting various data required for evaluation of integrity, a memorizing/storing device, an information processing device and a display device. Friction data as differential pressure signals of driving hydraulic pressures measured upon inspection/test operation of control rod drives and hydraulic pressure control system are taken into the input/output device. A result of processing for friction signal waveform pattern is calculated. The integrity and abnormality of the control rod drives and the hydraulic pressure system are evaluated using a causal relation between the result of the signal processing for obtained waveform patterns and the intelligence/knowledge of behaviors of the control rod devices and the hydraulic pressure control system thereby providing integrity data. Since the friction data can be calculated automatically by signal waveform pattern processing, there is no need to read the data manually by specialists who take part in the inspection and test. As a result, data on evaluation for integrity and abnormality of the control rod drives and the hydraulic pressure control system can be provided rapidly. (N.H.)

  3. Electro Hydraulic Hitch Control

    DEFF Research Database (Denmark)

    Hansen, M. R.; Andersen, T. O.; Nielsen, B.; Conrad, Finn

    2003-01-01

    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 h...

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

    OpenAIRE

    Huaizhong Chen

    2012-01-01

    This article describes the composition and working principle of electro-hydraulic position servo control system, and establishes a systematic mathematical model. This article presents a controller which is based on Fuzzy neural networks for an electro-hydraulic speed governor. The design process of the RBF Fuzzy neural network control is introduced in detail. This controller which combines the advantages of the Fuzzy control and Neutral networks control can get the best PID parameters by self...

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

    Science.gov (United States)

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

    2014-09-23

    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.

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

    DEFF Research Database (Denmark)

    Andersen, Torben Ole; Hansen, Michael Rygaard

    2005-01-01

    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

  7. Tap Water Hydraulic Control Systems - Design and Industrial Applications. Chapter 7 in Advances in Hydraulic Control Systems

    DEFF Research Database (Denmark)

    Conrad, Finn

    1996-01-01

    Deals with development and design of modern tap water hydraulic components and systems, in particalar the Danfoss Nessie-family of components and systems working with pure tap water without any kind of additives. Typical industrial applications are presented and the perspectives of new industrial applications and the environmental benefits are in focus, in particular in the food processing industry and in fire-fighting systems.

  8. Tap Water Hydraulic Control Systems - Design and Industrial Applications. Chapter 7 in Advances in Hydraulic Control Systems.

    DEFF Research Database (Denmark)

    Conrad, Finn

    1996-01-01

    Deals with development and design of modern tap water hydraulic components and systems, in particalar the Danfoss Nessie-family of components and systems working with pure tap water without any kind of additives. Typical industrial applications are presented and the perspectives of new industrial applications and the environmental benefits are in focus, in particular in the food processing industry and in fire-fighting systems.

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

    OpenAIRE

    Wang Yeqin

    2013-01-01

    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...

  10. Hydraulic system for the drive of control rod

    International Nuclear Information System (INIS)

    Purpose: To remove thermal stress and improve safety by utilizing water discharged a driving device as a part of cooling water for the device upon driving of control rods. Constitution: A water drain valve is wholly closed and a flow stabilization valve is supplied with an amount of water necessary for driving control rods. Upon driving one control rod, an amount of water required for the driving is caused to flow to the relivant hydraulic control unit and the flow rate in the stabilization valve is reduced by an amount required for the driving to keep the flow rate constant in the flow control valve. Since Excess water conventionally returned to the pressure vessel is utilized as cooling water for the driving device of control rods, the pressure vessel nozzle can be saved. Accordingly, the thermal stress in the nozzle portion can be removed to significantly improve the safety. (Seki, T.)

  11. Study on Control Strategy of Electro-Hydraulic Servo Loading System

    OpenAIRE

    Ju Tian

    2013-01-01

    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.

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

    Directory of Open Access Journals (Sweden)

    Huaizhong Chen

    2012-09-01

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

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

    DEFF Research Database (Denmark)

    Andersen, Torben Ole; Hansen, Michael Rygaard; Pedersen, Henrik Clemmensen

    2005-01-01

    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 n...

  14. Knowledge-based Adaptive Tracking Control of Electro-hydraulic Actuator Systems

    DEFF Research Database (Denmark)

    Hansen, Poul Erik

    1997-01-01

    The paper deal with intelligent motion control and electro-hydraulic actuator systems for multiaxis machynes and robots.The research results are from the IMCIA research Programme supported by the Danish Technical Research Council, STVF.

  15. An electro-hydraulic servo control system research for CFETR blanket RH

    International Nuclear Information System (INIS)

    Highlights: • We discussed the conceptual design of CFETR blanket RH maintenance system. • The mathematical model of electro-hydraulic servo system was calculated. • A fuzzy adaptive PD controller was designed based on control theory and experience. • The co-simulation models of the system were established with AMESim/Simulink. • The fuzzy adaptive PD algorithm was designed as the core strategy of the system. - Abstract: Based on the technical design requirements of China Fusion Engineering Test Reactor (CFETR) blanket remote handling (RH) maintenance, this paper focus on the control method of achieving high synchronization accuracy of electro-hydraulic servo system. Based on fuzzy control theory and practical experience, a fuzzy adaptive proportional-derivative (PD) controller was designed. Then a more precise co-simulation model was established with AMESim/Simulink. Through the analysis of simulation results, a fuzzy adaptive PD control algorithm was designed as the core strategy of electro-hydraulic servo control system

  16. An electro-hydraulic servo control system research for CFETR blanket RH

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Changqi [Hefei University of Technology, Hefei 230009, Anhui (China); Tang, Hongjun, E-mail: taurustang@126.com [Hefei University of Technology, Hefei 230009, Anhui (China); Qi, Songsong [Hefei University of Technology, Hefei 230009, Anhui (China); Cheng, Yong; Feng, Hansheng; Peng, Xuebing; Song, Yuntao [Institute of Plasma Physics Chinese Academy of Sciences, Hefei 230031, Anhui (China)

    2014-11-15

    Highlights: • We discussed the conceptual design of CFETR blanket RH maintenance system. • The mathematical model of electro-hydraulic servo system was calculated. • A fuzzy adaptive PD controller was designed based on control theory and experience. • The co-simulation models of the system were established with AMESim/Simulink. • The fuzzy adaptive PD algorithm was designed as the core strategy of the system. - Abstract: Based on the technical design requirements of China Fusion Engineering Test Reactor (CFETR) blanket remote handling (RH) maintenance, this paper focus on the control method of achieving high synchronization accuracy of electro-hydraulic servo system. Based on fuzzy control theory and practical experience, a fuzzy adaptive proportional-derivative (PD) controller was designed. Then a more precise co-simulation model was established with AMESim/Simulink. Through the analysis of simulation results, a fuzzy adaptive PD control algorithm was designed as the core strategy of electro-hydraulic servo control system.

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

    OpenAIRE

    Youxin Luo; Xiaoyi Che; Zhaoguo Chen

    2012-01-01

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

  18. Experimental study of the pressure discharge process for the hydraulic control rod drive system stepped cylinder

    International Nuclear Information System (INIS)

    The pressure discharge process from the stepped cylinder of the Hydraulic Control Rod Drive System (HCRDS) was studied experimentally in the HCRDS experimental loop for the 200 MW Nuclear Heating Reactor (NHR-200). The results showed that the differential pressure between the outside and the inside of the stepped cylinder increased rapidly to the desired value so that the force induced by the differential pressure which pushes the out tube of stepped cylinder was large enough. Therefore, if the hydraulic control rod were jammed, the pressure could push the hydraulic control rod to overcome the frictional resistance to insert the control rod into the reactor core. The experimental results verified that this design would solve the problem of hydraulic control rod jamming during an accident. (author)

  19. 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

  20. Electro Hydraulic Hitch Control

    DEFF Research Database (Denmark)

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

    2003-01-01

    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.

  1. Robust Adaptive Backstepping Control Design for a Nonlinear Hydraulic-Mechanical System

    DEFF Research Database (Denmark)

    Choux, Martin; Karimi, Hamid Reza

    2009-01-01

    The complex dynamics that characterize hydraulic systems make it difficult for the control design to achieve prescribed goals in an efficient manner. In this paper, we present the design and analysis of a robust nonlinear controller for a nonlinear hydraulic-mechanical (NHM) system. The system consists of an electrohydraulic servo valve and two hydraulic cylinders. Specifically, by considering a part of the dynamics of the NHM system as a norm-bounded uncertainty, two adaptive controllers are developed based on the backstepping technique that ensure the tracking error signals asymptotically converge to zero despite the uncertainties in the system according to the Barbalat lemma. The resulting controllers are able to take into account the interval uncertainties in Coulomb friction parameters and in the internal leakage parameters in the cylinders. Two adaptation laws are obtained by using the Lyapunov functional method and inequality techniques. Simulation results demonstrate the performance and feasibility ofthe proposed method.

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

    OpenAIRE

    Biedermann, Olaf; Geerling, Gerhard

    1998-01-01

    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 bl...

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

    DEFF Research Database (Denmark)

    Choux, Martin

    2011-01-01

    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.

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

    Science.gov (United States)

    Danko, George (Reno, NV)

    2011-11-22

    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.

  5. The logic control system of the control rods by hydraulic drive mechanism in the 5 MW nuclear heating reactor

    International Nuclear Information System (INIS)

    The authors describes the function and features of the logic control system to be applied to the control rods by hydraulic drive mechanism in the 5 MW nuclear heating reactor and the technical measures to enhance the availability and reliability of the system. The system coupling with hydraulic control rod drive mechanism consists of a whole control system in order to complete reactivity control of the nuclear reactor, the features of the system are stability, reliability and the high ability of anti-interference. It is successfully used in 5 MW nuclear heating reactor and meets the operational requirements of the reactor

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

    Science.gov (United States)

    Brennan, Daniel G

    2013-12-10

    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.

  7. Redundant hydraulic secondary flight control systems behavior in failure conditions

    OpenAIRE

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

    2013-01-01

    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...

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

    OpenAIRE

    CHOUX, M.; G. Hovland

    2010-01-01

    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 ...

  9. Robust H? positional control of 2-DOF robotic arm driven by electro-hydraulic servo system.

    Science.gov (United States)

    Guo, Qing; Yu, Tian; Jiang, Dan

    2015-11-01

    In this paper an H? positional feedback controller is developed to improve the robust performance under structural and parametric uncertainty disturbance in electro-hydraulic servo system (EHSS). The robust control model is described as the linear state-space equation by upper linear fractional transformation. According to the solution of H? sub-optimal control problem, the robust controller is designed and simplified to lower order linear model which is easily realized in EHSS. The simulation and experimental results can validate the robustness of this proposed method. The comparison result with PI control shows that the robust controller is suitable for this EHSS under the critical condition where the desired system bandwidth is higher and the external load of the hydraulic actuator is closed to its limited capability. PMID:26478475

  10. Cascade Controller Including Back-stepping for Hydraulic-Mechanical Systems

    DEFF Research Database (Denmark)

    Choux, Martin; Hovland, Geir; Blanke, Mogens

    2012-01-01

    Development of a cascade controller structure including adaptive backstepping for a nonlinear hydraulic-mechanical system is considered in this paper where a dynamic friction (LuGre) model is included to obtain the necessary accuracy. The paper compares the performance of two variants of an adaptive backstepping tracking controller with earlier results. The new control architecture is analysed and enhanced tracking performance is demonstrated when including the extended friction model. The compl...

  11. Kinematic study on hydraulic control rod driving system for HR-200 heating reactor

    International Nuclear Information System (INIS)

    In order to analyse the performance on the Hydraulic Control Rod Driving System for HR-200 Heating Reactor and the factors affecting its performance and some possible improvements on this system, a method is presented, that is, at first to linearize the two-order nonlinear differential equations by neglecting the multi-powered small quantities or segmenting, then to solve the linearized differential equations by using Laplace transformation. The motion rule of the control rod near the balance position is found and a simple numerical method to calculate the rod's movement on any position is proposed. The theoretical analyses and comparisons with experimental results are conducted. Both the theoretical analyses and the experiments show that with certain structural improvements and parameters change, this Hydraulic Control Rod Driving System will be able to work properly on HR-200. The main factors affecting the system's performance are analyzed and some reasonable improving methods are proposed

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

    Science.gov (United States)

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

    2007-04-01

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

  13. 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.)

  14. USE OF CIRCULATING PUMP WITH DIFFERENT PERFORMANCE CHARACTERISTICS IN WATER HEATING SYSTEMS AND THEIR INFLUENCE ON HYDRAULIC CONTROL SYSTEM / ?????????? ?????????????? ??????? ? ?????????? ???????????????? ? ???????? ???????? ????????? ? ??????? ?? ?? ?????????????? ????? ??????

    Directory of Open Access Journals (Sweden)

    Makhov Leonid Mikhaylovich / ????? ?????? ??????????

    2013-12-01

    Full Text Available The influence of the circulating pumps with different performance characteristics on automatically controlled water heating systems in cooperation with thermostatic valve is estimated. The results of the study of hydraulic control of water heating systems with their application are provided. The conclusions concerning cost-efficiency and effectiveness of operation of various circulating pumps are made / ??????? ??????? ?????????????? ??????? ? ?????????? ???????? ???????????????? ?? ?????????????? ????????????? ?????? ???????? ????????? ? ???????????? ? ??????????????. ????????? ?????????? ???????????? ??????????????? ?????? ?????? ???????? ????????? ??? ?? ??????????. ??????? ?????? ?? ????????????? ? ????????????? ????????????? ??? ??? ???? ?????????????? ???????

  15. A SDRE-based tracking control for a hydraulic actuation system

    Science.gov (United States)

    Strano, Salvatore; Terzo, Mario

    2015-08-01

    This paper presents the design and the experimental evaluation of a tracking control for a hydraulic actuation system in the presence of significant nonlinearities. The adopted control approach consists of a feedforward and a feedback term. The feedforward action is obtained from the known system dynamics and the feedback one is developed starting from the state-dependent Riccati equation (SDRE). The tracking performance of the presented control is demonstrated by means of both simulations and real-time experiments, solving the algebraic Riccati equation at each time step.

  16. Cascade Controller Including Back-stepping for Hydraulic-Mechanical Systems

    DEFF Research Database (Denmark)

    Choux, Martin; Hovland, Geir

    2012-01-01

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

  17. Water Hydraulic Systems

    DEFF Research Database (Denmark)

    Conrad, Finn

    2005-01-01

    The paper presents research results using IT-Tools for CAD and dynamic modelling, simulation, analysis, and design of water hydraulic actuators for motion control of machines, lifts, cranes and robots. Matlab/Simulink and CATIA are used as IT-Tools. The contributions include results from on-going research projects on fluid power and mechatronics based on tap water hydraulic servovalves and linear servo actuators and rotary vane actuators for motion control and power transmission. Development and...

  18. Water Hydraulic Systems

    DEFF Research Database (Denmark)

    Conrad, Finn

    2005-01-01

    The paper presents research results using IT-Tools for CAD and dynamic modelling, simulation, analysis, and design of water hydraulic actuators for motion control of machines, lifts, cranes and robots. Matlab/Simulink and CATIA are used as IT-Tools. The contributions include results from on-going research projects on fluid power and mechatronics based on tap water hydraulic servovalves and linear servo actuators and rotary vane actuators for motion control and power transmission. Development and design a novel water hydraulic rotary vane actuator for robot manipulators. Proposed mathematical modelling, control and simulation of a water hydraulic rotary vane actuator applied to power and control a two-links manipulator and evaluate performance. The results include engineering design and test of the proposed simulation models compared with IHA Tampere University’s presentation of research measurements from a similar robot manipulator driven by tap water hydraulic components. Experimental and simulation results are compared for evaluation and verification of developed mathematical models of the motion control of the manipulator. Furthermore, this paper presents the selected experimental results and performance results.

  19. Hydraulically centered control rod

    International Nuclear Information System (INIS)

    A control rod suspended to reciprocate in a guide tube of a nuclear fuel assembly has a hydraulic bearing formed at its lower tip. The bearing includes a plurality of discrete pockets on its outer surface into which a flow of liquid is continuously provided. In one embodiment the flow is induced by the pressure head in a downward facing chamber at the end of the bearing. In another embodiment the flow originates outside the guide tube. In both embodiments the flow into the pockets produces pressure differences across the bearing which counteract forces tending to drive the rod against the guide tube wall. Thus contact of the rod against the guide tube is avoided

  20. An energy-saving nonlinear position control strategy for electro-hydraulic servo systems.

    Science.gov (United States)

    Baghestan, Keivan; Rezaei, Seyed Mehdi; Talebi, Heidar Ali; Zareinejad, Mohammad

    2015-11-01

    The electro-hydraulic servo system (EHSS) demonstrates numerous advantages in size and performance compared to other actuation methods. Oftentimes, its utilization in industrial and machinery settings is limited by its inferior efficiency. In this paper, a nonlinear backstepping control algorithm with an energy-saving approach is proposed for position control in the EHSS. To achieve improved efficiency, two control valves including a proportional directional valve (PDV) and a proportional relief valve (PRV) are used to achieve the control objectives. To design the control algorithm, the state space model equations of the system are transformed to their normal form and the control law through the PDV is designed using a backstepping approach for position tracking. Then, another nonlinear set of laws is derived to achieve energy-saving through the PRV input. This control design method, based on the normal form representation, imposes internal dynamics on the closed-loop system. The stability of the internal dynamics is analyzed in special cases of operation. Experimental results verify that both tracking and energy-saving objectives are satisfied for the closed-loop system. PMID:26520165

  1. 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.

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

    OpenAIRE

    Lingxiao Quan; , Wei Zhang; Bin Yu; Liang Ha

    2013-01-01

    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...

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

    DEFF Research Database (Denmark)

    Schmidt, Lasse; Andersen, Torben Ole

    2014-01-01

    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 with conventional 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.

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

    DEFF Research Database (Denmark)

    Conrad, Finn; SŘrensen, Torben

    2003-01-01

    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 żThorż, 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.

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

    DEFF Research Database (Denmark)

    Schmidt, Lasse; Andersen, Torben Ole; Pedersen, Henrik C.

    2014-01-01

    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 a...

  6. 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...

  7. Development, field testing and implementation of automated hydraulically controlled, variable volume loading systems for reciprocating compressors

    Energy Technology Data Exchange (ETDEWEB)

    Hickman, Dwayne A. [ACI Services, Inc., Cambridge, OH (United States); Slupsky, John [Kvaerner Process Systems, Calgary, Alberta (Canada); Chrisman, Bruce M.; Hurley, Tom J. [Cooper Energy Services, Oklahoma City, OK (United States). Ajax Division

    2003-07-01

    Automated, variable volume unloaders provide the ability to smoothly load/unload reciprocating compressors to maintain ideal operations in ever-changing environments. Potential advantages provided by this load control system include: maximizing unit capacity, optimizing power economy, maintaining low exhaust emissions, and maintaining process suction and discharge pressures. Obstacles foreseen include: reliability, stability, serviceability and automation integration. Results desired include: increased productivity for the compressor and its operators, increased up time, and more stable process control. This presentation covers: system design features with descriptions of how different types of the devices were developed, initial test data, and how they can be effectively operated; three actual-case studies detailing the reasons why automated, hydraulically controlled, variable volume, head-end unloaders were chosen over other types of unloading devices; sophisticated software used in determining the device sizing and predicted performance; mechanical and field considerations; installation, serviceability and operating considerations; device control issues, including PC and PLC considerations; monitoring of actual performance and comparison of such with predicted performance; analysis of mechanical reliability and stability; and preliminary costs versus return on investment analysis. (author)

  8. Adaptive Sliding Mode Control for Hydraulic Drives

    DEFF Research Database (Denmark)

    Schmidt, Lasse; Andersen, Torben Ole; Pedersen, Henrik C.; Bech, Michael Mřller

    2013-01-01

    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 parameter...

  9. 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)

  10. Hydraulic Motor Driving Variable-Pitch System for Wind Turbine

    Directory of Open Access Journals (Sweden)

    Ye HUANG

    2013-11-01

    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.    

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

    DEFF Research Database (Denmark)

    Conrad, Finn Technical University of Denmark,

    2006-01-01

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

  12. 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

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

    Directory of Open Access Journals (Sweden)

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

    2013-01-01

    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.

  14. Some thermal-hydraulics aspects of the impurity control system for FED/INTOR

    International Nuclear Information System (INIS)

    This paper addresses two important aspects of thermal-hydraulics related to the design of limiter/divertor of Fusion Engineering Device and International Tokamak Reactor. The results of both analyses provide input to the determination of the lifetime of the limiter/divertor which is the most critical engineering problem for the impurity control system. The first part of the paper provides temperature calculations for the limiter and divertor. Steady-state, two-dimensional, temperature distributions are obtained, through the use of the computer code THTB, for the top surface of the limiter or divertor plate and for the leading edge (cylindrical geometry) of the limiter. Results are reported for various combinations of coating and structural materials. Thermal conductivity and coating thickness are found to be the most important parameters for given surface heat flux distributions. At the leading edge, there are two factors competing with each other when the coating material is relatively thick. The radial reduction in heat transfer area tends to increase the temperature while radiative heat transfer losses at high surface temperature tends to decrease the structural temperature. The second part of the paper describes the analysis of the tangential motion of a melt layer during plasma disruption. An analytical solution is developed. The results show that fairly large displacement (about 10 mm) could be reached under nominal conditions. Limitations of this analytical model are discussed and possible improvements are proposed

  15. Combined hydraulic and regenerative braking system

    Science.gov (United States)

    Venkataperumal, Rama R. (Troy, MI); Mericle, Gerald E. (Mount Clemens, MI)

    1981-06-02

    A combined hydraulic and regenerative braking system and method for an electric vehicle, with the braking system being responsive to the applied hydraulic pressure in a brake line to control the braking of the vehicle to be completely hydraulic up to a first level of brake line pressure, to be partially hydraulic at a constant braking force and partially regenerative at a linearly increasing braking force from the first level of applied brake line pressure to a higher second level of brake line pressure, to be partially hydraulic at a linearly increasing braking force and partially regenerative at a linearly decreasing braking force from the second level of applied line pressure to a third and higher level of applied line pressure, and to be completely hydraulic at a linearly increasing braking force from the third level to all higher applied levels of line pressure.

  16. Hydraulic servo system increases accuracy in fatigue testing

    Science.gov (United States)

    Dixon, G. V.; Kibler, K. S.

    1967-01-01

    Hydraulic servo system increases accuracy in applying fatigue loading to a specimen under test. An error sensing electronic control loop, coupled to the hydraulic proportional closed loop cyclic force generator, provides an accurately controlled peak force to the specimen.

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

    DEFF Research Database (Denmark)

    Conrad, Finn

    2006-01-01

    The paper presents and discusses a R&D-view on trends in development and best practise in modelling, simulation and design of both low-pressure and high-pressure tap water hydraulic components and systems for motion control as well as open-ended solutions various industrial applications. The focus is on the advantages using ordinary tap water and the range of application areas are illustrated with examples, in particular within the food processing industry, humidification operations, water mist ...

  18. Hydraulic control rod

    International Nuclear Information System (INIS)

    Disclosed is an apparatus for shifting a control rod into and out of a nuclear reactor utilizing as pressure fluid the fluid employed as coolant moderator in the reactor. 2 claims, 10 drawings figures

  19. 14 CFR 25.1435 - Hydraulic systems.

    Science.gov (United States)

    2010-01-01

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

  20. PLC Based Hydraulic Auto Ladle System

    OpenAIRE

    Amogh Tayade; Anuja Chitre

    2014-01-01

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

  1. Hydraulic drives for control rods

    International Nuclear Information System (INIS)

    Purpose: To improve the reliability of control rod drives by keeping the pipeway surface always dried thus to increase the life of the pipeways. Constitution: Water pressurized through a control rod driving water pump is heated to a constant temperature by a temperature adjusting device. The heated pressurized water is flown into a master control device, adjusted its pressure to a level required for each of the operations and sent to each of the hydraulic control units corresponding to control rod drives for the extraction and insertion of the control rods. Such temperature adjustment to the control rods driving water can avoid vapor condensation or the likes on the surface of the pipeways inside and outside of a reactor building due to temperature difference in winter and summer, so that no disadvantageous effects may be exerted on the pipeways. (Furukawa, Y.)

  2. 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)

  3. 14 CFR 23.1435 - Hydraulic systems.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Hydraulic systems. 23.1435 Section 23.1435... § 23.1435 Hydraulic systems. (a) Design. Each hydraulic system must be designed as follows: (1) Each hydraulic system and its elements must withstand, without yielding, the structural loads expected...

  4. 14 CFR 29.1435 - Hydraulic systems.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Hydraulic systems. 29.1435 Section 29.1435... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Equipment Miscellaneous Equipment § 29.1435 Hydraulic systems. (a) Design. Each hydraulic system must be designed as follows: (1) Each element of the hydraulic system...

  5. Hydraulic Actuation System with Active Control for the Lateral Suspensions of High Speed Trains

    OpenAIRE

    Gastaldi, Laura; Jacazio, Giovanni

    2013-01-01

    High speed trains normally use actively controlled pneumatic systems to recenter the carbody with respect to the bogie when the train negotiates a curve. Pneumatic systems are used because of their softness, which adds a little contribution to the elastic force generated by the mechanical springs of the lateral suspension system, thereby allowing the neccessary dynamic isolation between carbody and bogie. Howeve, pneumatic systems have the drawbacks of large dimensions and slow response, ofte...

  6. Experimental evaluation of control strategies for hydraulic servo robot

    DEFF Research Database (Denmark)

    Bech, Michael Mřller; Andersen, Torben Ole; Pedersen, Henrik C.; Schmidt, Lasse

    2013-01-01

    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 pape...

  7. Hydraulic Actuator for Ganged Control Rods

    Science.gov (United States)

    Thompson, D. C.; Robey, R. M.

    1986-01-01

    Hydraulic actuator moves several nuclear-reactor control rods in unison. Electromagnetic pump pushes liquid lithium against ends of control rods, forcing them out of or into nuclear reactor. Color arrows show lithium flow for reactor startup and operation. Flow reversed for shutdown. Conceived for use aboard spacecraft, actuator principle applied to terrestrial hydraulic machinery involving motion of ganged rods.

  8. Transputer Control of Hydraulic Actuators and Robots

    DEFF Research Database (Denmark)

    Conrad, Finn

    1996-01-01

    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 re...

  9. Precision Force Control for an Electro-Hydraulic Press Machine

    OpenAIRE

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

    2014-01-01

    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...

  10. PLC Based Hydraulic Auto Ladle System

    Directory of Open Access Journals (Sweden)

    Amogh Tayade

    2014-03-01

    Full Text Available In this paper we have implemented a PLC based Hydraulic Auto Ladle System for Casting Department of Victory Precisions Pvt. Ltd. Chakan, Pune. This project work presents the study and design of PLC based Hydraulic Auto Ladle System. Aluminium pouring is the key process in Casting and Forging industry. Different products are manufactured by the company for automobile sector using aluminium. Programmable Logic Controller (PLC is used for the automation of pouring process. Automation is done to increase the accuracy and consistency in the quality of the product. Human errors, while pouring the aluminium, which in-turn results in defective production are eliminated by introducing automation.

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

    DEFF Research Database (Denmark)

    Conrad, Finn; Sřrensen, Torben

    2003-01-01

    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 prop...

  12. Precision Force Control for an Electro-Hydraulic Press Machine

    Directory of Open Access Journals (Sweden)

    Hong-Ming Chen

    2014-08-01

    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.

  13. 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

  14. 14 CFR 25.1435 - Hydraulic systems.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Hydraulic systems. 25.1435 Section 25.1435... STANDARDS: TRANSPORT CATEGORY AIRPLANES Equipment Miscellaneous Equipment § 25.1435 Hydraulic systems. (a) Element design. Each element of the hydraulic system must be designed to: (1) Withstand the proof...

  15. 14 CFR 27.1435 - Hydraulic systems.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Hydraulic systems. 27.1435 Section 27.1435... STANDARDS: NORMAL CATEGORY ROTORCRAFT Equipment Safety Equipment § 27.1435 Hydraulic systems. (a) Design. Each hydraulic system and its elements must withstand, without yielding, any structural loads...

  16. Plug & Play Control of Hydraulic Networks

    DEFF Research Database (Denmark)

    Jensen, Tom NŘrgaard

    2012-01-01

    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.

  17. Hydraulic Yaw System

    DEFF Research Database (Denmark)

    Stubkier, Sřren; Pedersen, Henrik C.; Mřrkholt, M.

    2012-01-01

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

  18. Experimental evaluation of control strategies for hydraulic servo robot

    DEFF Research Database (Denmark)

    Bech, Michael MŘller; Andersen, Torben Ole

    2013-01-01

    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.

  19. Robust Control of a Hydraulically Actuated Manipulator Using Sliding Mode Control

    DEFF Research Database (Denmark)

    Hansen, Michael Rygaard; Andersen, Torben Ole; Pedersen, Henrik Clemmensen

    2005-01-01

    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 ...

  20. Modified hydraulic braking system limits angular deceleration to safe values

    Science.gov (United States)

    Briggs, R. S.; Council, M.; Green, P. M.

    1966-01-01

    Conventional spring actuated, hydraulically released, fail-safe disk braking system is modified to control the angular deceleration of a massive antenna. The hydraulic system provides an immediate preset pressure to the spring-loaded brake shoes and holds it at this value to decelerate the antenna at the desired rate.

  1. Modeling, Optimization & Control of Hydraulic Networks

    DEFF Research Database (Denmark)

    Tahavori, Maryamsadat

    2014-01-01

    Water supply systems consist of a number of pumping stations, which deliver water to the customers via pipeline networks and elevated reservoirs. A huge amount of drinking water is lost before it reaches to end-users due to the leakage in pipe networks. A cost effective solution to reduce leakage in water network is pressure management. By reducing the pressure in the water network, the leakage can be reduced significantly. Also it reduces the amount of energy consumption in water networks. The primary purpose of this work is to develop control algorithms for pressure control in water supply systems. To have better understanding of water leakage, to control pressure and leakage effectively and for optimal design of water supply system, suitable modeling is an important prerequisite. Therefore a model with the main objective of pressure control and consequently leakage reduction is presented. The nonlinear network model is derived based on the circuit theory. A suitable projection is used to reduce the state vector and to express the model in standard state-space form. Then, the controllability of nonlinear nonaffine hydraulic networks is studied. The Lie algebra-based controllability matrix is used to check if the network is controllable. Afterward the pressure control problem in water supply systems is formulated as an optimal control problem. The goal is to minimize the power consumption in pumps and also to regulate the pressure drop at the end-users to a desired value. The formulated optimal control problem is non-convex. To solve the nonlinear optimal control problem, first the maximum principle is used. Subsequently the toolbox ICLOCS is used to solve the optimal control problem. In ICLOCS the nonlinear problem solver IPOPT is used. The IPOPT uses the interior point optimization method to solve nonlinear optimal control problems. In the water supply system model, the hydraulic resistance of the valve is estimated by real data and it is considered to be a disturbance. The disturbance in our system is updated every 24 hours based on the amount of water usage by consumers every day. Model Predictive Control can handle disturbances much better compared with the other control strategies. Therefore the pressure control problem is formulated within model predictive control framework. Because of nonlinearity which we have in both cost function and constraints, the model predictive control method could only solve the problem for a short time frame (three hours). Solving model predictive control and optimal control problems for large-scale, nonlinear, non-convex systems generally is not trivial. There are a lot of computational prob-lems and issues such as sensitivity, feasibility and computational burden which one has to face with. To cope with these problems a static approximation is used. The steady state model of water network is derived by removing all dynamics in the system. The problem of pressure management in new system is presented in the form of nonlinear non-convex optimization problem. The toolbox IPOPT is used to solve this optimization problem. Water supply companies are dividing their networks into pressure zones to enable better control of leakages in their networks. Dividing the network into different pressure zones in the optimal way is a non-trivial task. The problem of dividing the pressure zones in an optimal way is studied in the last part of this Ph.D. study. To this end, the problem is formulated as an optimization problem, which minimizes the power consumption in all pumping stations and maintains the pressure at end-users bigger than some specific values. The defined optimization problem is solved for all possible pump positions in the network and an optimal place of an extra pumping station is found.

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

    OpenAIRE

    Heybroek, Kim

    2008-01-01

    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...

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

    OpenAIRE

    Walter Kucharczyk; Andrew A. Goldenberg; Cyrus Raoufi

    2008-01-01

    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...

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

    DEFF Research Database (Denmark)

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

    2003-01-01

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

  5. Controlling a negative loaded hydraulic cylinder using pressure feedback

    DEFF Research Database (Denmark)

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

    2010-01-01

    This paper is concerned with the inherent oscillatory nature of pressure compensated velocity control of a hydraulic cylinder subjected to a negative load and suspended by means of an over-center valve. Initially, a linearized stability analysis of such a hydraulic circuit is carried out clearly showing that without extra measures such a system will be unstable in a substantial part of the cylinder stroke. The stability criterion is expressed in hard quantities: Cylinder volumes, cylinder area r...

  6. Intelligent PI Fuzzy Control of An Electro-Hydraulic Manipulator

    OpenAIRE

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

    2012-01-01

    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 ...

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

    Energy Technology Data Exchange (ETDEWEB)

    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

    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.

  8. 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

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

    OpenAIRE

    Xu, Yaozhong

    2013-01-01

    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...

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

    Science.gov (United States)

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

    2014-07-01

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

  11. Robust Control of a Hydraulically Actuated Manipulator Using Sliding Mode Control

    DEFF Research Database (Denmark)

    Hansen, Michael Rygaard; Andersen, Torben Ole

    2005-01-01

    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.

  12. Simulation and control of an electro-hydraulic actuated clutch

    Science.gov (United States)

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

    2011-08-01

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

  13. 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

  14. 49 CFR 570.55 - Hydraulic brake system.

    Science.gov (United States)

    2010-10-01

    ...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...

  15. 14 CFR 33.72 - Hydraulic actuating systems.

    Science.gov (United States)

    2010-01-01

    ... 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...

  16. Linear Perturbation Adaptive Control of Hydraulically Driven Manipulators

    DEFF Research Database (Denmark)

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

    2004-01-01

    A method for synthesis of a robust adaptive scheme for a hydraulically driven manipulator, that takes full advantage of any known system dynamics to simplify the adaptive control problem for the unknown portion of the dynamics is presented. The control method is based on adaptive perturbation control.Using the Lyapunov approach, under slowly time-varying assumptions, it is shown that the tracking error and the parameter error remain bounded. This bound is a function of the ideal parameters and a bounded disturbance. The control algorithm decouples and linearizes the manipulator so that each joint behaves as an independent second-order system with fixed dynamics.

  17. 49 CFR 570.55 - Hydraulic brake system.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 6 2010-10-01 2010-10-01 false Hydraulic brake system. 570.55 Section 570.55... 10,000 Pounds § 570.55 Hydraulic brake system. The following requirements apply to vehicles with hydraulic brake systems. (a) Brake system failure indicator. The hydraulic brake system failure...

  18. 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

  19. Development of NTD Hydraulic Rotation System for Kijang Research Reactor

    International Nuclear Information System (INIS)

    The KJRR will be mainly utilized for isotope production, NTD (Neutron Transmutation Doping) production, and related research activities. During irradiation for the NTD process, the irradiation rigs containing the silicon ingot rotate at a constant speed to ensure precisely defined homogeneity of the irradiation. The NTDHRS requires only hydraulic piping conveniently routed to the rotating devices inside the reactor pool. The resulting layout leaves the pool area clear of obstructions which might obscure vision and hinder target handling for operators. Pump banks and control valves are located remotely in a dedicated plant room allowing easy access and online maintenance. The necessities and major characteristic of NTD hydraulic rotation system are described in this study. A new NTD hydraulic rotation system are being developed to rotate the irradiation rigs at a constant speed and supply cooling flow for the irradiation rigs and reflector assembly. The configuration of the NTD hydraulic rotation device is discussed and practical methods to improve the rotational performance are suggested

  20. Adaptive Sliding Mode Control for Hydraulic Drives : A New Approach

    DEFF Research Database (Denmark)

    Schmidt, Lasse; Andersen, Torben Ole

    2013-01-01

    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.

  1. Dynamic analysis of hydraulic control unit

    International Nuclear Information System (INIS)

    The Hydraulic Control Units (HCU) are required to operate when the required response spectra (RRS) corresponding to dynamic loads of upset and faulted conditions are applied to the HCU's. To demonstrate operability, they are qualified to testing response spectra (TRS). This paper presents a procedure by which the RRS and TRS were generated at the upper HCU connecting locations and also the selected locations. A comparison of the RRS and TRS shows that the RRS are indeed enveloped by the TRS at the mounting locations as well as at the floor. Thus, the use of the HCU test results to qualify the HCU in the actual installation is justified. (orig.)

  2. Plug & Play Control of Hydraulic Networks

    DEFF Research Database (Denmark)

    Jensen, Tom Nřrgaard

    2012-01-01

    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...

  3. Controlling a negative loaded hydraulic cylinder using pressure feedback

    DEFF Research Database (Denmark)

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

    2010-01-01

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

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

    DEFF Research Database (Denmark)

    Pedersen, Henrik C.; Andersen, Torben Ole

    2009-01-01

    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 comprise the 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.

  5. A Novel Energy Recovery System for Parallel Hybrid Hydraulic Excavator

    OpenAIRE

    Wei Li; Baoyu Cao; Zhencai Zhu; Guoan Chen

    2014-01-01

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

  6. Hydraulic Motor Driving Variable-Pitch System for Wind Turbine

    OpenAIRE

    Ye HUANG; JiBao QI

    2013-01-01

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

  7. 49 CFR 571.105 - Standard No. 105; Hydraulic and electric brake systems.

    Science.gov (United States)

    2010-10-01

    ... the brake control. Hydraulic brake system means a system that uses hydraulic fluid as a medium for transmitting force from a service brake control to the service brake, and that may incorporate a brake power... muscular force on the service brake control. Brake power unit means a device installed in a brake...

  8. Fort St. Vrain hydraulic power system study

    International Nuclear Information System (INIS)

    This report prepared for the United States Department of Energy under Contract Number DEAC03-80SF11440, contains the results of the Fort St. Vrain Hydraulic Power System (System 91) engineering study. The major objectives of this study were to evaluate, analyze, and recommend corrective actions to resolve HTGR (High Temperature Gas Cooled Reactor) operational problems and equipment performance problems in the hydraulic power system at the Fort St. Vrain Nuclear Generating Station. The recommended corrective actions for each subject are subdivided where appropriate, into two categories: modifications suggested for implementation at Fort St. Vrain and modifications suggested for consideration in the design of future HTGRs

  9. Evolution of hydraulic system for moving components on Tore Supra

    Energy Technology Data Exchange (ETDEWEB)

    Samaille, F.; Journeaux, J.Y.; Doceul, L.; Giraud, G.; Pasquier, G. [Association Euratom-CEA Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee

    1998-07-01

    Specific diagnostics as Langmuir probe measurement and RF heating systems require fast and accurate displacement of components. This is provided by an active hydraulic system that has been working since 1988 with a high reliability on Tore Supra. At the present time, two LHCD launchers, three ICRH antennae and two fast moving probes are actively moved. Later, for the Tore Supra next step CIEL project (Composants Internes Et Limiteurs) that is planned for the year 2000, the Toroidal Pump Limiter (TPL) positioning and the fast shutters pumping duct will also be actively controlled. This paper describes the design of the present day Tore Supra hydraulic system and the new original hydraulic systems required for the Toroidal Pump Limiter. (author)

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

    Science.gov (United States)

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

    2014-11-01

    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

  11. Hydraulic control rod drive for a nuclear reactor

    International Nuclear Information System (INIS)

    The invention pertains to the desing of a controllable lock for the axial movement of the piston rod of a hydraulic control rod drive. The lock is ineffective during seram and unintentional control rod withdrawal. (UWI)

  12. Thermal Equilibrium of a Hydraulic Driving System

    Directory of Open Access Journals (Sweden)

    Tarawneh S. Muafag

    2004-01-01

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

  13. Hydraulic model of the systemic resistance.

    Czech Academy of Sciences Publication Activity Database

    Leitermann, D.; Pražák, Josef; Musil, Jan; Poušek, L.; Konvi?ková, S.

    San Diego : American Society of Biomechanics, 2001, s. 265-266. [Conference of the American Society of Biomechanics. San Diego (US), 08.08.2001-11.08.2001] Grant ostatní: ÚT AV ?R(XC) PP50252 Institutional research plan: CEZ:AV0Z2076919 Keywords : systemic resistance * hydraulic model * cardiovascular system Subject RIV: BK - Fluid Dynamics

  14. FOREWORD: 26th IAHR Symposium on Hydraulic Machinery and Systems

    Science.gov (United States)

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

    2012-11-01

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

  15. Concept Evaluation for Hydraulic Yaw System

    DEFF Research Database (Denmark)

    Stubkier, SŘren; Pedersen, Henrik C.

    2013-01-01

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

  16. Hydraulics.

    Science.gov (United States)

    Decker, Robert L.; Kirby, Klane

    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)…

  17. Reactor Shutdown Mechanism by Top-mounted Hydraulic System

    International Nuclear Information System (INIS)

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

  18. 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

  19. Hydraulic fluid properties and its influence on system performance

    OpenAIRE

    Singireddy, Swaroop Reddy; Javalagi, Santosh

    2012-01-01

    Hence hydraulic fluid is the medium of power transfer in hydraulic equipment, it is important to know the properties of hydraulic fluids and its influence on system performance. There are different types of fluids based on their availability, working purpose etc. So selection of fluid depends on the working conditions of the hydraulic equipment. So to select a fluid one has to be clear about the operating conditions of hydraulic equipment and this can be achieved by testing the equipment with...

  20. Modeling of a Hydraulic Braking System

    OpenAIRE

    Lundin, Christopher

    2015-01-01

    The objective of this thesis is to derive an analytical model representing a reduced form of a mine hoist hydraulic braking system. Based primarily on fluid mechanical and mechanical physical modeling, along with a number of simplifying assumptions, the analytical model will be derived and expressed in the form of a system of differential equations including a set of static functions. The obtained model will be suitable for basic simulation and analysis of system dynamics, with the aim to cap...

  1. Hydraulic device for control rod drives

    International Nuclear Information System (INIS)

    Purpose: To enable to select the volume of nitrogen gases supplied from a nitrogen gas container connected to an accumulator depending on the reactor pressure, etc. Constitution: A scram valve is opened by a scram signal upon reactor scram. In this case, if the reactor pressure is low, nitrogen gases in the first nitrogen container are supplied to an accumulator and high pressure scram water from a hydraulic pressure supply device is supplied to the control rod drives. On the other hand, if the reactor pressure is high, the first and the second nitrogen containers are opened and volume-increased nitrogen gases are supplied to the accumulator. As the result, reactor scram can be conducted with a sufficient margin in which the pressure in the nitrogen container is reduced as the stroke or the time of the control rod is greater to increase the effective energy in the latter half region of the scram where the scram stroke is great. Accordingly, it is possible to improve the safety and the reliability of the reactor core. (Kamimura, M.)

  2. Logic Threshold Based Energy Control Strategy for Parallel Hydraulic Hybrid Vehicles

    OpenAIRE

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

    2013-01-01

    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...

  3. 14 CFR 33.72 - Hydraulic actuating systems.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Hydraulic actuating systems. 33.72 Section... AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.72 Hydraulic actuating systems. Each hydraulic actuating system must function properly under all conditions in which...

  4. Thermal Equilibrium of a Hydraulic Driving System

    OpenAIRE

    Tarawneh S. Muafag; Faisal M.M. Al-Gathian

    2004-01-01

    To put into evidence the consequence of the energetic losses that appears in a hydraulic driving systems and to evaluate how does the system performance and reliability are strongly affected by the temperature increase due-to the flowing fluid, in this study a thermal analysis is presented for improving the possibility of developing a practical and simplified method for establishing the optimum working temperature at any instant time. Focus is on computational methods that to be used for cont...

  5. 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)

  6. 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

  7. A hydraulic transient analysis tool for power plant piping systems

    International Nuclear Information System (INIS)

    A hydraulic transient computer simulation procedure is presented which is capable of simulating the waterhammer response of power plant liquid piping systems under a variety of forcing functions. The procedure, which models most current pipeline hardware, is suitable for simulating events such as valve operation, pump start-up and shutdown, and the dynamic action of PID controllers. Application of the procedure in an actual analysis of a condensate polisher and feedwater system is discussed

  8. Concept Evaluation for Hydraulic Yaw System

    DEFF Research Database (Denmark)

    Stubkier, Sřren; Pedersen, Henrik C.; Andersen, Torben Ole

    2013-01-01

    The yaw system is the subsystem on a wind turbine which ensures that the rotor plane of the turbine always is facing the wind direction. Studies from [1] show that a soft yaw system may be utilized to dampen the loads in the wind turbine structure. The soft yaw system operates much like a suspension system on a car, leading the loads away from the turbine structure. However, to realize a soft hydraulic yaw system a new design concept must be found. As a part of the development of the new concept...

  9. Light Water Breeder Reactor movable fuel hydraulic balancing system (LWBR Development Program)

    International Nuclear Information System (INIS)

    Reactivity control in the Light Water Breeder Reactor (LWBR) is obtained by axial positioning of twelve movable fuel assemblies, which thus serve the dual purpose of contributing to reactor power and functioning as neutron economic control elements. A hydraulic technique is used to automatically counterbalance the upward hydraulic force of these elements. Hydraulic balancing is accomplished using the Bypass Inlet Flow (BIF) balancing system, which utilizes the core coolant inlet pressure to develop a downward hydraulic force on the control elements of equal magnitude to the upward hydraulic force caused by axial flow of coolant through the movable control elements. Thus the net force acting on each control element is approximately equal to the weight of the element and acts in a downward direction at all coolant flow rates. This net force adequately accelerates the control element to satisfy automatic insertion requirements. The BIF system also provides for limiting the velocity of downward motion and for decelerating the fuel assembly at the bottom of its stroke. The logic underlying the selection of the BIF system as the appropriate component of the Reactivity Control System to provide control element insertion integrity is discussed, the components comprising the control elements and the BIF piping network used in the Light Water Breeder Reactor are described, and a discussion of the BIF system operation is presented. Descriptions of full-scale hydraulic testing resulting in qualification of the analytical model, and of useful supplementary information acquired from BIF system hydraulic testing are also included as appendices

  10. Mathematical Models of Hydraulic Systems, Examples, Analysis.

    Czech Academy of Sciences Publication Activity Database

    Straškraba, Ivan

    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

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

    OpenAIRE

    Zoran ?ukan Majki?

    2013-01-01

    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...

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

    Directory of Open Access Journals (Sweden)

    Vašina M.

    2013-04-01

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

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

    OpenAIRE

    Vašina M.; Hružík L.; Bure?ek A.

    2013-01-01

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

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

    Science.gov (United States)

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

    2013-01-01

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

  15. Automated Hydraulic System Design and Power Management in Mobile Applications

    DEFF Research Database (Denmark)

    Pedersen, Henrik Clemmensen

    2007-01-01

    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. hoses and 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

  16. Rubber seals for fluid and hydraulic systems

    CERN Document Server

    Chandrasekaran, Chellappa

    2009-01-01

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

  17. Power Management in Mobile Hydraulic Applications - An Approach for Designing Hydraulic Power Supply Systems

    DEFF Research Database (Denmark)

    Pedersen, Henrik Clemmensen

    2004-01-01

    Throughout the last three decades energy consumption has become one of the primary design aspects in hydraulic systems, especially for mobile hydraulic systems, as power and cooling capacity here is at limited disposal. Considering the energy usage, this is dependent on component efficiency, but even more important is the system topology. However, there are no rules or guidelines for what system topology to choose for a given application, in order to obtain the most energy efficient system, nor ...

  18. The use of loop-seals for the control of the overpressures in hydraulic transients evolving in a sea service water system

    Science.gov (United States)

    Canetta, D.; Capozza, A.; Iovino, G.

    The transient response following pump trip-offs and start-ups was investigated in the sea water system of a nuclear power plant. Specific care was devoted to water column separation and cavity collapse phenomena. A computer program designed for analysis of complex hydraulic networks was used. It is found that dangerous overpressures can be avoided by the use of loop seals. The design of the vacuum breaker valves of the loop seals and the optimization of overall transient behavior is discussed.

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

    DEFF Research Database (Denmark)

    Schmidt, Lasse; Andersen, Torben Ole; Pedersen, Henrik C.

    2014-01-01

    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 ...

  20. Design Rules for High Damping in Mobile Hydraulic Systems

    OpenAIRE

    Axin, Mikael; Krus, Petter

    2013-01-01

    This paper analyses the damping in pressure compensated closed centre mobile working hydraulic systems. Both rotational and linear loads are covered and the analysis applies to any type of pump controller. Only the outlet orifice in the directional valve will provide damping to a pressure compensated system. Design rules are proposed for how the system should be dimensioned in order to obtain a high damping. The volumes on each side of the load have a high impact on the damping. In case of a ...

  1. Automated Hydraulic System Design and Power Management in Mobile Applications

    DEFF Research Database (Denmark)

    Pedersen, Henrik Clemmensen

    2007-01-01

    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 th...

  2. Shock analysis on hydraulic drive control rod during scram

    International Nuclear Information System (INIS)

    Control rod hydraulic drive mechanism (CRHDM) is a new invention of Institute of Nuclear and New Energy Technology of Tsinghua University. The hydraulic absorber buffers the control rod when it scrams. The control rod fast drop impact experiment was conducted and the key parameters of control rod hydraulic buffering performance were obtained. Based on the test results and according to D'Alembert principle, the maximum inertial impact force on the control rod during the fast drop period was applied as equivalent static load force on the control rod. The deformations and stress distributions on the control rod in this worst case were calculated by using finite element software ABAQUS. Calculation results were compared with the experiment results, and it was verified that nonlinear transient dynamics analysis in this problem can be simplified as static analysis. Damage criterion of the control rod fast drop impact process was also given. And it lays foundation for optimal design of the control rod and hydraulic absorber. (authors)

  3. Analysis of and H? Controller Design For An Electro-Hydraulic Servo Pressure Regulator

    DEFF Research Database (Denmark)

    Stubkier, SŘren; Pedersen, Henrik C.

    2011-01-01

    Currently mobile hydraulics is in a transition phase, where electronic sensors and digital signal processors are becoming standard on a high number of machines, hereby replacing hydraulic pilot lines and offering new possibilities with regard to both control and feasibility. As most open-circuit pumps are still hydraulically controlled, there is however still a need for being able to generate a hydraulic pilot pressure. The focus of the current paper is on the analysis and controller design of an electrohydraulic servo pressure regulator, which generates a hydraulic LS-pressure for a variable displacement pump based on an electrical reference. The paper first presents the considered system and an experimentally verified model of this. A linearized model and a stability analysis is then presented, based on which an H?control strategy is selected. A nominal performance and a robustly stable controller are designed and tested in simulation and experimentally. Finally both controllers are compared to the reference system, finding that similar performance may be obtained, but the used FPGA limits the performance.

  4. Fundamental Research on Hydraulic Systems Driven by Alternating Flow

    OpenAIRE

    Ioan-Lucian Marcu; Daniel-Vasile Banyai

    2012-01-01

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

  5. Sliding Control with Chattering Elimination for Hydraulic Drives

    DEFF Research Database (Denmark)

    Schmidt, Lasse; Andersen, Torben Ole; Pedersen, Henrik C.; Bech, Michael Mřller

    2012-01-01

    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...

  6. Hydraulic braking system for loads subjected to impacts and vibrations

    International Nuclear Information System (INIS)

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

  7. Borehole hydraulic coal mining system analysis

    Science.gov (United States)

    Floyd, E. L.

    1977-01-01

    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.

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-04-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    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

    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.

  11. Hydraulically actuated hexapod robots design, implementation and control

    CERN Document Server

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

    2014-01-01

    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...

  12. System for Continuous Deaeration of Hydraulic Oil

    Science.gov (United States)

    Anderson, Christopher W.

    2006-01-01

    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.

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

    DEFF Research Database (Denmark)

    Sřrensen, Rasmus Mřrk; Hansen, Michael Rygaard; Mouritsen, Ole Ř.

    2011-01-01

    This paper presents a new hydraulic yaw system for wind turbines. The basic component is a new type of hydraulic motor characterized by an extraordinary high specific displacement yielding high output torque in a compact form. The focus in the paper is the volumetric efficiency of the motor, which is based on leakage flow. The most critical gaps in the motor, across the end faces of the rotor, are investigated both by a fluid structural interaction simulation model and by experimental prototype ...

  14. Structure Parameters Optimization Analysis of Hydraulic Hammer System

    OpenAIRE

    Guoping Yang; Jian Fang

    2012-01-01

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

  15. Hydraulic power take-off for wave energy systems

    DEFF Research Database (Denmark)

    Christensen, Georg Kronborg

    2001-01-01

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

  16. 1st International Conference on Hydraulic Design in Water Resources Engineering : Channels and Channel Control Structures

    CERN Document Server

    1984-01-01

    The development of water resources has proceeded at an amazing speed around the world in the last few decades. The hydraulic engineer has played his part: in constructing much larger artificial channels than ever before, larger and more sophisticated control structures, and systems of irrigation, drainage and water supply channels in which the flow by its nature is complex and unsteady requiring computer-based techniques at both the design and operation stage. It seemed appropriate to look briefly at some of the developments in hydraulic design resulting from this situation. Hence the idea of the Conference was formed. The Proceedings of the Conference show that hydraulic engineers have been able to acquire a very substantial base of design capability from the experience of the period referred to. The most outstanding development to have occurred is in the combination of physical and mathematical modelling, which in hydraulic engineering has followed a parallel path to that in other branches of engineering sc...

  17. A conceptual model of check dam hydraulics for gully control

    Directory of Open Access Journals (Sweden)

    C. Castillo

    2013-09-01

    Full Text Available 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.

  18. 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 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

  19. Design of Pumps for Water Hydraulic Systems

    DEFF Research Database (Denmark)

    Klit, Peder; Olsen, Stefan; Bech, Thomas Nřrgaard

    1999-01-01

    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.

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

    DEFF Research Database (Denmark)

    Conrad, Finn Technical University of Denmark,

    2005-01-01

    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.

  1. 46 CFR 128.240 - Hydraulic or pneumatic power and control-materials and pressure design.

    Science.gov (United States)

    2010-10-01

    ...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...

  2. Robust Control of Industrial Hydraulic Cylinder Drives - with Special Reference to Sliding Mode- & Finite-Time Control

    DEFF Research Database (Denmark)

    Schmidt, Lasse

    2014-01-01

    In industry, performance requirements regarding machinery, applications etc., are constantly increasing, and with the development of reliable proportional flow control components to reasonable prices, the market is increasingly turning its attention toward controllable fluid power solutions. For series produced systems such as presses etc., dedicated controls are often developed. However, the great majority of the hydraulic systems developed, are produced in limited numbers for specialized appli...

  3. Hydraulic control of an automatic transmission

    Energy Technology Data Exchange (ETDEWEB)

    Oberhausen, A.

    1986-04-01

    Since the energy crysis took place it becomes very important to investigate the whole car concept in respect of fuel economy. As one of the steps Ford Transmission Engineering Cologne developed a new automatic 4-speed lock-up overdrive transmission which is called A4LD. The torque converter will be locked in 3rd and 4th gear. The 4th gear is designed as an overdrive gear with a ratio of 0.75:1 which reduces the engine speed by 25%. This report describes the main control items and the controlling of each gear.

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

    DEFF Research Database (Denmark)

    Schmidt, Lasse; Andersen, Torben Ole

    2014-01-01

    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.

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

    DEFF Research Database (Denmark)

    Stecki, J. S.; Conrad, Finn; Matheson, P.; Rush, A.

    2002-01-01

    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.

  6. Is the Faroe Bank Channel a hydraulically-controlled overflow?

    Science.gov (United States)

    Girton, J. B.; Pratt, L. J.; Helfrich, K.; Sutherland, D.; Price, J. F.

    2004-12-01

    The overflow of dense water from the Nordic Seas through the Faroe Bank Channel (FBC) has attributes suggesting hydraulic control, including an asymmetry across the sill reminiscent of flow over a dam. However, because of the influence of the earth's rotation, as well as the presence of continuous gradients in velocity and density, the standard approach of looking for a Froude number (v/? {g'd}) of unity to diagnose criticality is not adequate. Of primary importance is the nature and speed of information-carrying waves---the flow is subcritical if any of these waves can travel upstream, supercritical if no waves can travel upstream, and critical if the fastest waves are arrested by the flow. We present a comparison of several different techniques for assessing the hydraulic criticality of overflows applied to data from a set of velocity and density sections across the FBC. These include: 1) modifications to the (non-rotating) local Froude number to account for shear and stratification in the flow; 2) rotating hydraulic solutions using a constant potential vorticity layer in a channel of parabolic cross-section; and 3) direct computation of shallow water wave speeds from the observed overflow structure, using a newly-developed generalized hydraulic condition and multiple-streamtube approach. Two of these three methods give similar answers, suggesting the location of control to be 60-100 km downstream of the sill and not at the sill itself. We discuss the implications of these results for hydraulic predictions of overflow transport and variability, as well as reasons for the failure of the parabolic model.

  7. Hydraulic Soft Yaw System for Multi MW Wind Turbines

    DEFF Research Database (Denmark)

    Stubkier, SŘren

    2013-01-01

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

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

    DEFF Research Database (Denmark)

    Hansen, Anders Hedegaard; Hansen, Rico Hjerm; Pedersen, Henrik C.

    2012-01-01

    Fluid power is the leading technology in Power Take Off(PTO) systems in Wave Energy Converters(WEC’s), due to the capability of generating high force at low velocity. However, as hydraulic force controlling system may suffer from large energy losses the efficiency of the hydraulic PTO systems may be a limiting factor for wave energy. Therefore, a secondary controlled force system has been proposed as PTO element for WEC’s. This paper investigates the configuration of a multi-chamber cylinder uti...

  9. Hydraulic Modeling of a Mixed Water Level Control Hydromechanical Gate

    OpenAIRE

    Cassan, Ludovic; Baume, Jean-Pierre; Belaud, Gilles; Litrico, Xavier; Malaterre, Pierre-Olivier; Ribot-Bruno, José

    2011-01-01

    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...

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

    DEFF Research Database (Denmark)

    Schmidt, Lasse; Andersen, Torben Ole

    2013-01-01

    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.

  11. Modeling, Optimization & Control of Hydraulic Networks

    DEFF Research Database (Denmark)

    Tahavori, Maryamsadat

    2014-01-01

    Water supply systems consist of a number of pumping stations, which deliver water to the customers via pipeline networks and elevated reservoirs. A huge amount of drinking water is lost before it reaches to end-users due to the leakage in pipe networks. A cost effective solution to reduce leakage in water network is pressure management. By reducing the pressure in the water network, the leakage can be reduced significantly. Also it reduces the amount of energy consumption in water networks. The ...

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

    International Nuclear Information System (INIS)

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

  13. 46 CFR 128.240 - Hydraulic or pneumatic power and control-materials and pressure design.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Hydraulic or pneumatic power and control-materials and... Hydraulic or pneumatic power and control—materials and pressure design. (a) Each standard piping component (such as pipe runs, fittings, flanges, and standard valves) for hydraulic or pneumatic power and...

  14. 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

  15. 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

  16. More efficient fluid power systems using variable displacement hydraulic motors

    OpenAIRE

    Biedermann, Olaf; Engelhardt, Jörg; Geerling, Gerhard

    1998-01-01

    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 sys...

  17. Model-based open-loop control design for a hydraulic brake system with switching solenoid valves; Modellbasierter Steuerungsentwurf fuer ein hydraulisches Bremssystem mit magnetischen Schaltventilen

    Energy Technology Data Exchange (ETDEWEB)

    Lolenko, K.; Fehn, A.A.R. [Robert Bosch GmbH, Abstatt (Germany). CC/ESM

    2007-02-15

    This paper presents a novel concept for the model-based open-loop control design of switching solenoid valves. The control is suitable for the wheel brake calliper pressure setting during vehicle dynamics control, as e. g. by ESP or ABS [1;11]. For the control design the reduced model, taking into account all essential nonlinearities of the system as well as environmental effects (e.g. temperature), was derived from the detailed simulation model. The transition times and other characteristic time intervals describing the dynamic behaviour of the solenoid valve are calculated from the equations of the reduced model through symbolic integration or approximative by means of taylor series. The calculated time intervals serve to define the control impulse duration of the valve from the desired calliper pressure. In simulation studies the designed control has been proven to be an efficient approach and allows improved pressure control accuracy for conventional brake systems. (orig.)

  18. A Frequency Response Approach to Sliding Control Design for Hydraulic Drives

    DEFF Research Database (Denmark)

    Schmidt, Lasse; Johansen, Per

    2014-01-01

    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.

  19. A 6-DOF vibration isolation system for hydraulic hybrid vehicles

    Science.gov (United States)

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

    2006-03-01

    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.

  20. Contaminant monitoring of hydraulic systems. The need for reliable data

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-12-31

    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.

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

    OpenAIRE

    SONG Yunpu

    2012-01-01

    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...

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

    International Nuclear Information System (INIS)

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

  3. Hydraulic External Pre-Isolator System for LIGO

    CERN Document Server

    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

    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.

  4. Optimal Control of Nonlinear Hydraulic Networks in the Presence of Disturbance

    DEFF Research Database (Denmark)

    Tahavori, Maryamsadat; Leth, John-Josef; Kallesře, Carsten; Wisniewski, Rafal

    2014-01-01

    Water leakage is an important component of water loss. Many methods have emerged from urban water supply systems for leakage control, but it still remains a challenge in many countries. Pressure management is an effective way to reduce the leakage in a system. It can also reduce the power consumption. To this end, an optimal control strategy is proposed in this paper. In the water supply system model, the hydraulic resistance of the valve is estimated by the real data from a water supply system ...

  5. A new approach for failure prediction in mobile hydraulic systems

    Energy Technology Data Exchange (ETDEWEB)

    Oppermann, M.

    2007-07-01

    In this work a new approach to set up a condition monitoring (CM) system for mobile hydraulic systems is investigated. This approach focuses on an early detection and allocation of impending failures without modelling the hydraulic system and using a minimum amount on additional sensor information. In a first step critical components of mobile hydraulic systems are specified that may be worthy for diagnostics. Based on a demonstrator machine, a wheel loader, critical sub modules are brought out and possible applicable CM-methods are specified and selected. Two basic methods - the thermodynamic and the structure borne noise method - are investigated and combined. The new CM-approach is experimentally investigated on two different laboratory test rigs by implementing a large number of different artificial faults. The laboratory tests are also used to determine the minimum requirements on system information. Finally the proposed methods are implemented on a mobile off-road vehicle and tested under different operational conditions in-field. (orig.)

  6. A Novel Control Approach Based on Second Order Sliding Modes & Its Application to Hydraulic Drives

    DEFF Research Database (Denmark)

    Schmidt, Lasse; Andersen, Torben Ole

    2013-01-01

    Sliding modes impose strong robustness toward parametric plant uncertainties and disturbances and 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. 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 introduces additional design parameters and actuator dynamics may not allow the desired control accuracy to be reached. In this paper a novel control approach based on second order sliding modes utilizing the idea of the power rate reaching law is introduced. Dependent on parameters the proposed controller may preserve the main features of sliding controls, while at the same time avoiding control chattering. Simulation studies confirm the announced properties when applied to a hydraulic drive model subjected to strong variations in supply pressure and friction.

  7. Modeling and Simulation of Power Coupling System in Hydraulic Hybrid City Bus

    OpenAIRE

    Xunming Li; Jinyu Qu; Wei Wei; Xiangyu Tian

    2014-01-01

    In order to solve the coupling problem of power in Hydraulic Hybrid City Bus (HHB), a hydraulic hybrid power coupling system based on planetary gear transmission principle is proposed in this paper. The system consists of diesel engine, power coupler, hydraulic pump/motor, etc. The realizable operating modes of power coupling system are analyzed in this paper. Under coordination of clutches, the engine driven mode, hydraulic driven mode, hybrid driven mode, hydraulic en...

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

    Energy Technology Data Exchange (ETDEWEB)

    D. S. Lucas

    2004-10-01

    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.

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

    Directory of Open Access Journals (Sweden)

    SONG Yunpu

    2012-11-01

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

  10. 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 it an attractive approach for model-based observer/controller design applications in automotive systems

  11. REDUCE ON ENERGY HYDRAULIC SHOCK IN LOCK PROTECTION DEVICE OF THE HYDRAULIC SYSTEM OF CONSTRUCTION AND ROAD MACHINES / ???????? ??????? ??????????????? ????? ? ???????? ?????????? ???????????? ???????????-???????? ???????

    Directory of Open Access Journals (Sweden)

    Fomenko Nikolai Aleksandrovich / ??????? ??????? ?????????????

    2015-02-01

    Full Text Available The authors propos technical solution to the reduce on energy hydraulic shock in lock protection device of the hydraulic system of construction and road machines from unauthorized discharge of working fluid in the destruction of the high pressure hoses / ???????????? ??????????? ??????? ???????? ??????? ??????????????? ????? ? ???????? ?????????? ?????? ?????????????? ??????? ???????????-???????? ????? ?? ???????????????????? ??????? ??????? ???????? ??? ?????????? ??????? ???????? ????????

  12. The Newest Hydraulic Engineering

    International Nuclear Information System (INIS)

    This book gives descriptions of basic of hydraulic pressure engineering, hydraulic fluid such as properties of hydraulic fluid, kinds of it, kinds and effect of addition, choice and repair of hydraulic fluid, and aeration, characteristic of flow of air current, like throttle, flow between both parallel sides, silting, hydraulic look and squeeze effect, hydraulic oil pump with definition and classification, gear pump vane pump, hydraulic control valve, hydraulic cylinder, hydraulic revolved motor, pressure transmitter, pipe and basic circuit of hydraulics.

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

    DEFF Research Database (Denmark)

    Schmidt, Lasse; Andersen, Torben Ole; Pedersen, Henrik C.; Bech, Michael Mřller

    2013-01-01

    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...

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

    OpenAIRE

    Biedermann, Olaf

    2000-01-01

    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...

  15. Non Linear Modelling and Control of Hydraulic Actuators

    Directory of Open Access Journals (Sweden)

    B. Šulc

    2002-01-01

    Full Text Available This paper deals with non-linear modelling and control of a differential hydraulic actuator. The nonlinear state space equations are derived from basic physical laws. They are more powerful than the transfer function in the case of linear models, and they allow the application of an object oriented approach in simulation programs. The effects of all friction forces (static, Coulomb and viscous have been modelled, and many phenomena that are usually neglected are taken into account, e.g., the static term of friction, the leakage between the two chambers and external space. Proportional Differential (PD and Fuzzy Logic Controllers (FLC have been applied in order to make a comparison by means of simulation. Simulation is performed using Matlab/Simulink, and some of the results are compared graphically. FLC is tuned in a such way that it produces a constant control signal close to its maximum (or minimum, where possible. In the case of PD control the occurrence of peaks cannot be avoided. These peaks produce a very high velocity that oversteps the allowed values.

  16. Hydraulic simulation of the Vodice water supply system

    OpenAIRE

    ?epon, Jerneja

    2008-01-01

    Many Slovenian communities are facing drinking water supply issues. Major problems are the life span of pipelines and other supply system equipment, undersized water supply network and inappropriate pipeline material. The community of Vodice is facing the previously- described issues. A need to reconstruct and recondition the drinking water pipeline system was identified. It was necessary to develop a hydraulic model of Vodice’s drinking water pipeline system. A simulation, based on the hydra...

  17. Current evaluation of hydraulics to replace the cable force transmission system for body-powered upper-limb prostheses.

    Science.gov (United States)

    LeBlanc, M

    1990-01-01

    Present body-powered upper-limb prostheses use a cable control system employing World War II aircraft technology to transmit force from the body to the prosthesis for operation. The cable and associated hardware are located outside the prosthesis. Because individuals with arm amputations want prostheses that are natural looking with a smooth, soft outer surface, a design and development project was undertaken to replace the cable system with hydraulics located inside the prosthesis. Three different hydraulic transmission systems were built for evaluation, and other possibilities were explored. Results indicate that a hydraulic force transmission system remains an unmet challenge as a practical replacement for the cable system. The author was unable to develop a hydraulic system that meets the necessary dynamic requirements and is acceptable in size and appearance. PMID:10149042

  18. 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)

    A.P. Rusakov

    2011-01-01

    Full Text Available The goal of these investigations is modeling of processes and studying of influence of quantitative characteristics and parameters in heating and cooling subsystem of ventilation and air conditioning systems at balancing this subsystem by means of various balancing valves and control of three-running valve. Balancing and management processes are considered on an example of the binding water air-heater of ventilation and air conditioning system. Besides, influence of various regime parameters on considered balancing characteristics is studied, as that: difference of pressure in a network of a heat supply, the pressure created by the pump, their parity, various water temperatures, the modes leading to self-oscillations. Result of work is reception of balancing and adjusting characteristics of a considered subsystem in most general view under various working conditions and their further analysis.

  19. Nonlinear stability research on the hydraulic system of double-side rolling shear

    Science.gov (United States)

    Wang, Jun; Huang, Qingxue; An, Gaocheng; Qi, Qisong; Sun, Binyu

    2015-10-01

    This paper researches the stability of the nonlinear system taking the hydraulic system of double-side rolling shear as an example. The hydraulic system of double-side rolling shear uses unsymmetrical electro-hydraulic proportional servo valve to control the cylinder with single piston rod, which can make best use of the space and reduce reversing shock. It is a typical nonlinear structure. The nonlinear state-space equations of the unsymmetrical valve controlling cylinder system are built first, and the second Lyapunov method is used to evaluate its stability. Second, the software AMEsim is applied to simulate the nonlinear system, and the results indicate that the system is stable. At last, the experimental results show that the system unsymmetrical valve controlling the cylinder with single piston rod is stable and conforms to what is deduced by theoretical analysis and simulation. The construction and application of Lyapunov function not only provide the theoretical basis for using of unsymmetrical valve controlling cylinder with single piston rod but also develop a new thought for nonlinear stability evaluation.

  20. The development of radiation hardened robot for nuclear facility - Development of embedded controller for hydraulic robot

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Byung Kook; Kim, Jae Kwon [Korea Advanced Institute of Science and Technology, Taejon (Korea)

    2000-04-01

    We designed and implemented a reliable hierarchical control system for hydraulic robots for nuclear power plant maintenance. In hazardous environments such as nuclear power plants, robot systems or automated equipment should be used instead of human being for maintenance and repair. Such robot should guarantee high reliability in hazardous environments such as high radiation or high temperature. The overall system is composed of three hierarchical subsystems: i) supervisory controller in safe zone for operator interaction with monitoring and commanding and graphic user interface, ii) master controller in semi-hazardous zone for control function, and iii) slave controller in hazardous zone for sensing and actuation. These subsystems are connected with suitable communication channels: a) master-slave communication channel implemented with CAN (Control Area Network) and b) supervisory-master communication with Ethernet. The master and the slave controllers construct a feedback closed-loop control system. In order to improve reliability, the slave controller is duplicated using cold-standby scheme, and master-slave communication channel is also duplicated. The overall system is implemented harmonically, and we obtained fast control interval of 1msec, which is sufficient for high-performance real-time control. 12 refs., 58 figs., 13 tabs. (Author)

  1. 49 CFR 570.57 - Air brake system and air-over-hydraulic brake subsystem.

    Science.gov (United States)

    2010-10-01

    ...false Air brake system and air-over-hydraulic brake subsystem. 570.57 Section...57 Air brake system and air-over-hydraulic brake subsystem. The following requirements...vehicles with air brake and air-over-hydraulic brake systems. Trailer(s)...

  2. Experimental-based Modelling and Simulation of Water Hydraulic Mechatronics Test Facilities for Motion Control and Operation in Environmental Sensitive Applications` Areas

    DEFF Research Database (Denmark)

    Conrad, Finn; Pobedza, J.

    2003-01-01

    The paper presents experimental-based modelling, simulation, analysis and design of water hydraulic actuators for motion control of machines, lifts, cranes and robots. The contributions includes results from on-going research projects on fluid power and mechatronics based on tap water hydraulic proportional valves and servo actuators for motion control and power transmission undertaken in co-operation by Technical University, DTU and Cracow University of Technology, CUT. The results of this research co-operation include engineering design and test of simulation models compared with two mechatronic test rig facilities powered by environmental friendly water hydraulic servo actuator system. Test rigs with measurement and data acquisition system were designed and build up with tap water hydraulic components of the Danfoss Nessie® product family. This paper presents selected experimental and identifying test results for a water hydraulic system.

  3. Aircraft hydraulic power system diagnostic, prognostics and health management

    OpenAIRE

    WANG, JIAN

    2012-01-01

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

  4. Hydraulic Soft Yaw System for Multi MW Wind Turbines

    DEFF Research Database (Denmark)

    Stubkier, Sřren

    2013-01-01

    Horizontal axis wind turbines utilize a yaw system to keep the rotor plane of the wind turbine perpendicular to the main wind direction. If the wind direction changes, the wind turbine follows the direction change by yawing. If the wind turbine does not yaw, there will be a reduction in produced energy and an increase in the loading of the wind turbine structure and components. This dissertation examines the hypothesis that there are advantages of basing a yaw system on hydraulic components inst...

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

    DEFF Research Database (Denmark)

    Hansen, Anders Hedegaard; Hansen, Rico Hjerm

    2012-01-01

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

  6. TMI-2 in-vessel hydraulic systems utilize high water and high boron content fluids

    International Nuclear Information System (INIS)

    Choice of a hydraulic fluid for use in the Three Mile Island Unit 2 (TMI-2) reactor vessel defueling equipment required consideration of the following constraints for the hydraulic fluid given an accidental spill into the reactor coolant system (RCS). The TMI-2 RCS hydraulic fluid utilized in the hydraulic operations utilized a solution composition of 95 wt% water and 5 wt% of the above base fluid. The TMI-2 hydraulic system utilizes pressures up to 3500 psi. The selected hydraulic fluid has been in use since December 1986 with minimal operational difficulties

  7. Calculation of dynamic hydraulic forces in nuclear plant piping systems

    International Nuclear Information System (INIS)

    A computer code was developed as one of the tools needed for analysis of piping dynamic loading on nuclear power plant high energy piping systems, including reactor safety and relief value upstream and discharge piping systems. The code calculates the transient hydraulic data and dynamic forces within the one-dimensional system, caused by a pipe rupture or sudden value motion, using a fixed space and varying time grid-method of characteristics. Subcooled, superheated, homogeneous two-phase and transition flow regimes are considered. A non-equilibrium effect is also considered in computing the fluid specific volume and fluid local sonic velocity in the two-phase mixture. Various hydraulic components such as a spring loaded or power operated value, enlarger, orifice, pressurized tank, multiple pipe junction (tee), etc. are considered as boundary conditions. Comparisons of calculated results with available experimental data shows a good agreement. (Author)

  8. Hydraulic problems in cooling water recirculating systems of nuclear power plants

    International Nuclear Information System (INIS)

    Hydraulic design problems of the structures in the free-surface part of the recirculating system (intake and distribution structure, control weir, cooling tower) are described. The capacity of the cooling system required for realization of once-through cooling, blow-down, recirculation and mixed mode operation is discussed, and experimental and numerical methods of solution are illustrated by means of several representative investigations of existing and planned installations. (orig.)

  9. Pneumatic and Hydraulic Systems in Coal Fluidized Bed Combustor

    OpenAIRE

    Z. O. Opafunso; I. I. Ozigis; I.A. Adetunde

    2009-01-01

    Problem statement: This study designed the pneumatic and hydraulic systems in coal fluidized bed combustor. These are fluidization of silica sand bed material, Air distributor, centrifugal fan, electric motor power drive and surface heat exchanger. Approach: The effects of increased gas velocity on silica sand and the resultant drag force formed the basic equations in fluidization. Air distributor was introduced to achieve pressure drop across the beds. Results: The constructed centrifugal fa...

  10. Logic Threshold Based Energy Control Strategy for Parallel Hydraulic Hybrid Vehicles

    Directory of Open Access Journals (Sweden)

    Liu-Tao

    2013-08-01

    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.

  11. A device for the hydraulic control of nuclear reactor control rods

    International Nuclear Information System (INIS)

    A device for driving and locking the control rods of a nuclear reactor. This device comprises a hydraulic driving piston mounted in a cylinder provided with a construction for absorbing shocks. The piston is provided, at is extremity, with a locking device adapted to engage a stationary lock, it being possible to control the latter for freeing said piston locking device; with such an arrangement, the control rod is normally maintained in position, and it can be freed only by a positive signal. Moreover, the control rod movements are slowed down, so as to prevent the gripping device from being damaged. This device can be used in the nuclear industry

  12. Three Mile Island system thermal-hydraulic analysis using TRAC

    International Nuclear Information System (INIS)

    The Three Mile Island (TMI) nuclear plant was modeled using the Transient Reactor Analysis Code (TRAC) and a preliminary calculation, which simulated the initial part of the accident that occurred on March 28, 1979, was performed. The purpose of this calculation was to provide a better understanding of the system thermal-hydraulic response during the first 3 h of the accident and to evaluate how well TRAC results compared to the overall accident scenario and measured system parameters. The calculated system pressure, loop temperatures, and pressurizer level are all in good agreement with measured data

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

    Scientific Electronic Library Online (English)

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

    2010-03-01

    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.

  14. IT-Tools Concept for Simulation and Design of Water Hydraulic Mechatronic Test Facilities for Motion Control and Operation in Environmentally Sensitive Application Areas

    DEFF Research Database (Denmark)

    Conrad, Finn; Pobedza, J.; Sobczyk, A.

    2004-01-01

    This paper presents a proposed IT-Tools concept for modeling, simulation, analysis and design of water hydraulic actuators for motion control of machines, lifts, cranes and robots. The designed test rigs have tap water hydraulic components of the Danfoss Nessie® product family and equipped with a measurement and data acquisition system. Results of the mathematical modeling, simulation and design of the motion control test rigs are presented. Furthermore, the paper presents selected experimental ...

  15. Nanocoatings for High-Efficiency Industrial Hydraulic and Tooling Systems

    Energy Technology Data Exchange (ETDEWEB)

    Clifton B. Higdon III

    2011-01-07

    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.

  16. Numerical analysis of a rub-impact rotor-bearing system for hydraulic generating set

    International Nuclear Information System (INIS)

    In this article, vibration characteristics of a rub-impact rotor-bearing system excited by unbalanced magnetic pull (UMP) for hydraulic generating set are investigated. The rubbing model used consists of the radial elastic impact and the tangential Coulomb friction. Through numerical calculation, the excitation current, eccentricity are used as the control parameters, investigating their effect on the rub-impact rotor-bearing system, by bifurcation diagrams, Poincaré maps, trajectories, and frequency spectrums. Various nonlinear phenomena, including period-one, period-five, quasi-period and chaotic motions, are induced and the system stability is obviously influenced due to the UMP. In addition, it is found that the large eccentricity that exceeds to a certain extent may lead to the full annular rubbing from the partial rubbing. The results can provide some theoretical references for the safety operation and rub-impact fault diagnosis of the hydraulic generating set.

  17. Reducing leaks in water distribution networks. Controlling pressure by means of automatic hydraulic valves; Reduccion de fugas en redes de distribucion de agua. Control de la presion mediante valvulas hidraulicas automaticas

    Energy Technology Data Exchange (ETDEWEB)

    Singla Font, S.

    2005-07-01

    Any water distribution network, bet it of drinking water or irrigation water, always loses an inevitable amount. One of the main ways to reduce leaks is to optimise the pressure in the network by means of hydraulic valves with different types of control devices. These can be either completely hydraulic or supplemented by electronic systems. (Author)

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

    Directory of Open Access Journals (Sweden)

    Zoran ?ukan Majki?

    2013-10-01

    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

  19. FONESYS: The FOrum and NEtwork of SYStem Thermal-Hydraulic Codes in Nuclear Reactor Thermal-Hydraulics

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, S.H., E-mail: k175ash@kins.re.kr [Korea Institute of Nuclear Safety (KINS) (Korea, Republic of); Aksan, N., E-mail: nusr.aksan@gmail.com [University of Pisa San Piero a Grado Nuclear Research Group (GRNSPG) (Italy); Austregesilo, H., E-mail: henrique.austregesilo@grs.de [Gesellschaft für Anlagen- und Reaktorsicherheit (GRS) (Germany); Bestion, D., E-mail: dominique.bestion@cea.fr [Commissariat ŕ l’énergie atomique et aux énergies alternatives (CEA) (France); Chung, B.D., E-mail: bdchung@kaeri.re.kr [Korea Atomic Energy Research Institute (KAERI) (Korea, Republic of); D’Auria, F., E-mail: f.dauria@ing.unipi.it [University of Pisa San Piero a Grado Nuclear Research Group (GRNSPG) (Italy); Emonot, P., E-mail: philippe.emonot@cea.fr [Commissariat ŕ l’énergie atomique et aux énergies alternatives (CEA) (France); Gandrille, J.L., E-mail: jeanluc.gandrille@areva.com [AREVA NP (France); Hanninen, M., E-mail: markku.hanninen@vtt.fi [VTT Technical Research Centre of Finland (VTT) (Finland); Horvatovi?, I., E-mail: i.horvatovic@ing.unipi.it [University of Pisa San Piero a Grado Nuclear Research Group (GRNSPG) (Italy); Kim, K.D., E-mail: kdkim@kaeri.re.kr [Korea Atomic Energy Research Institute (KAERI) (Korea, Republic of); Kovtonyuk, A., E-mail: a.kovtonyuk@ing.unipi.it [University of Pisa San Piero a Grado Nuclear Research Group (GRNSPG) (Italy); Petruzzi, A., E-mail: a.petruzzi@ing.unipi.it [University of Pisa San Piero a Grado Nuclear Research Group (GRNSPG) (Italy)

    2015-01-15

    Highlights: • We briefly presented the project called Forum and Network of System Thermal-Hydraulics Codes in Nuclear Reactor Thermal-Hydraulics (FONESYS). • We presented FONESYS participants and their codes. • We explained FONESYS projects motivation, its main targets and working modalities. • We presented FONESYS position about projects topics and subtopics. - Abstract: The purpose of this article is to present briefly the project called Forum and Network of System Thermal-Hydraulics Codes in Nuclear Reactor Thermal-Hydraulics (FONESYS), its participants, the motivation for the project, its main targets and working modalities. System Thermal-Hydraulics (SYS-TH) codes, also as part of the Best Estimate Plus Uncertainty (BEPU) approaches, are expected to achieve a more-and-more relevant role in nuclear reactor technology, safety and design. Namely, the number of code-users can easily be predicted to increase in the countries where nuclear technology is exploited. Thus, the idea of establishing a forum and a network among the code developers and with possible extension to code users has started to have major importance and value. In this framework the FONESYS initiative has been created. The main targets of FONESYS are: • To promote the use of SYS-TH Codes and the application of the BEPU approaches. • To establish acceptable and recognized procedures and thresholds for Verification and Validation (V and V). • To create a common ground for discussing envisaged improvements in various areas, including user-interface, and the connection with other numerical tools, including Computational Fluid Dynamics (CFD) Codes.

  20. FONESYS: The FOrum and NEtwork of SYStem Thermal-Hydraulic Codes in Nuclear Reactor Thermal-Hydraulics

    International Nuclear Information System (INIS)

    Highlights: • We briefly presented the project called Forum and Network of System Thermal-Hydraulics Codes in Nuclear Reactor Thermal-Hydraulics (FONESYS). • We presented FONESYS participants and their codes. • We explained FONESYS projects motivation, its main targets and working modalities. • We presented FONESYS position about projects topics and subtopics. - Abstract: The purpose of this article is to present briefly the project called Forum and Network of System Thermal-Hydraulics Codes in Nuclear Reactor Thermal-Hydraulics (FONESYS), its participants, the motivation for the project, its main targets and working modalities. System Thermal-Hydraulics (SYS-TH) codes, also as part of the Best Estimate Plus Uncertainty (BEPU) approaches, are expected to achieve a more-and-more relevant role in nuclear reactor technology, safety and design. Namely, the number of code-users can easily be predicted to increase in the countries where nuclear technology is exploited. Thus, the idea of establishing a forum and a network among the code developers and with possible extension to code users has started to have major importance and value. In this framework the FONESYS initiative has been created. The main targets of FONESYS are: • To promote the use of SYS-TH Codes and the application of the BEPU approaches. • To establish acceptable and recognized procedures and thresholds for Verification and Validation (V and V). • To create a common ground for discussing envisaged improvements in various areas, including user-interface, and the connection with other numerical tools, including Computational Fluid Dynamics (CFD) Codes

  1. 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)

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

    DEFF Research Database (Denmark)

    Schmidt, Lasse; Andersen, Torben Ole

    2013-01-01

    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.

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

    Science.gov (United States)

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

    2013-04-01

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

  4. Linear hydraulic drive system for a Stirling engine

    Science.gov (United States)

    Walsh, Michael M. (Schenectady, NY)

    1984-02-21

    A hydraulic drive system operating from the periodic pressure wave produced by a Stirling engine along a first axis thereof and effecting transfer of power from the Stirling engine to a load apparatus therefor and wherein the movable, or working member of the load apparatus is reciprocatingly driven along an axis substantially at right angles to the first axis to achieve an arrangement of a Stirling engine and load apparatus assembly which is much shorter and the components of the load apparatus more readily accessible.

  5. Study on Knowledge -based Intelligent Fault Diagnosis of Hydraulic System

    Directory of Open Access Journals (Sweden)

    Xuexia Liu

    2012-12-01

    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.

  6. Evaluation of Bulk Modulus of Oil System with Hydraulic Line

    Directory of Open Access Journals (Sweden)

    Bure?ek A.

    2013-04-01

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

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

    Directory of Open Access Journals (Sweden)

    Guoping LIU

    2013-11-01

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

  8. 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

  9. Hydraulic manipulator research at ORNL

    Energy Technology Data Exchange (ETDEWEB)

    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

    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.

  10. Evidence for internal hydraulic control in the northern Řresund

    DEFF Research Database (Denmark)

    Nielsen, Morten Holtegaard

    2001-01-01

    New observations of mainly flow velocity, salinity, and temperature are used to show and discuss some of the physical conditions in Oslashresund, the strait between Denmark and Sweden, one of three connections between the brackish Baltic Sea and the saline North Sea. The main geometric features are a contraction in the northern Oslashresund and the shallow Drogden sill at the entrance to the Baltic. The observations show that the two-layer flows through the contraction are often hydraulically co...

  11. Optimal hydraulic design of new-type shaft tubular pumping system

    International Nuclear Information System (INIS)

    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 ?-? 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.

  12. Optimal hydraulic design of new-type shaft tubular pumping system

    Science.gov (United States)

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

    2012-11-01

    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.

  13. Thermal Hydraulic Analysis on Containment Filtered Venting System

    International Nuclear Information System (INIS)

    In this study, the thermal hydraulic conditions (e. g. pressure and flow rate) at each component have been examined and the sensitivity analysis on CFVS design parameters (e. g. water inventory, volumetric flow rate). The purpose is to know the possible range of flow conditions at each component to determine the optimum size of filtration system. GOTHIC code has been used to simulate the thermal-hydraulic behavior inside of CFVS. The behavior of flows in the CFVS has been investigated. The vessel water level and the flow rates during the CFVS operation are examined. It was observed that the vessel water level would be changed significantly due to steam condensation/thermal expansion and steam evaporation. Therefore, the vessel size and the initial water inventory should be carefully determined to keep the minimum water level required for filtration components and not to flood the components in the upper side of the vessel. It has been also observed that the volumetric flow rate is maintained during the CFVS operation, which is beneficial for pool scrubbing units. However, regarding the significant variations at the orifice downstream, careful design would be necessary

  14. Thermal Hydraulic Analysis on Containment Filtered Venting System

    Energy Technology Data Exchange (ETDEWEB)

    Bang, Young Suk; Park, Tong Kyu; Lee, Doo Yong; Lee, Byung Chul [FNC Technology Co. Ltd., Yongin (Korea, Republic of); Lee, Sang Won; Kim, Hyeong Taek [KHNP-Central Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    In this study, the thermal hydraulic conditions (e. g. pressure and flow rate) at each component have been examined and the sensitivity analysis on CFVS design parameters (e. g. water inventory, volumetric flow rate). The purpose is to know the possible range of flow conditions at each component to determine the optimum size of filtration system. GOTHIC code has been used to simulate the thermal-hydraulic behavior inside of CFVS. The behavior of flows in the CFVS has been investigated. The vessel water level and the flow rates during the CFVS operation are examined. It was observed that the vessel water level would be changed significantly due to steam condensation/thermal expansion and steam evaporation. Therefore, the vessel size and the initial water inventory should be carefully determined to keep the minimum water level required for filtration components and not to flood the components in the upper side of the vessel. It has been also observed that the volumetric flow rate is maintained during the CFVS operation, which is beneficial for pool scrubbing units. However, regarding the significant variations at the orifice downstream, careful design would be necessary.

  15. Top actuated reactor control system

    International Nuclear Information System (INIS)

    A nuclear reactor control system employing a plurality of low worth absorber elements which can be individually moved between two positions respectively commensurate with full insertion and full retraction. Each absorber element actuator assembly is a top actuated device located entirely within the reactor pressure vessel and utilizing hydraulic pressure to control and monitor absorber element position. Each absorber element is contained in a guide tube which extends through the fuel assembly. (Patent Office Record)

  16. Experimental Study on Cartesian-Space PD Control for Hydraulic Manipulator

    Directory of Open Access Journals (Sweden)

    Sang-Uk Chon

    2014-08-01

    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

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

    OpenAIRE

    Rijo, Manuel; Arranja, Carina

    2005-01-01

    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...

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

    DEFF Research Database (Denmark)

    Jensen, Tom NŘrgaard; Wisniewski, Rafal

    2014-01-01

    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.

  19. Evaluation of thermal-hydraulic parameters for different spectral shift control schemes

    International Nuclear Information System (INIS)

    The past decade has seen a steady escalation in light water reactor (LWR) capital costs, to the point where it is no longer assured that LWRs can generate electrical energy cheaper than coal-fired units, particularly in the United States. The objective of this work is to examine ways in which design simplification can be exploited to reduce nuclear power reactor construction and operating costs. The elimination of poison control in pressurized water reactors (PWRs) has been found a suitable subject for investigation. In this analysis, full reactivity control using boiling during operation has been examined. The ramifications of boiling in a PWR clearly involve many aspects of plant design and operation, such that the analysis could serve a prototypic function for subsequent studies on other plant systems. Spectral shift control using boiling-enhanced voids or moderator displacement offers considerable promise for better uranium utilization. However, schemes to implement such modes of control imply severe challenges to a number of practical engineering constraints. Because of this, thermal-hydraulic parameters have been evaluated for a limiting-case SSCR using only moderator control for different control schemes. The NTHAD code has been used in the present work

  20. Stabilizing Gap of Pole Electric Arc Furnace Using Smart Hydraulic System

    Directory of Open Access Journals (Sweden)

    Maher Yahya Sallom

    2015-03-01

    Full Text Available Electric arc furnace applications in industry are related to position system of its pole, up and down of pole. The pole should be set the certain gap. These setting are needed to calibrate. It is done manually. In this research will proposed smart hydraulic to make this pole works as intelligent using proportional directional control valve. The output of this research will develop and improve the working of the electric arc furnace. This research requires study and design of the system to achieve the purpose and representation using Automation Studio software (AS, in addition to mathematically analyzed and where they were building a laboratory device similar to the design and conduct experiments to study the system in practice and compared with simulation.Experimental tests show that the performance of electro hydraulic closed loop system (EHCLS for position control is good and the output results are good and acceptable. The practical results and simulation using (AS software are clearly convergence. It was concluded that the possibility of the implementation of this project in industrial processes such as electric arc furnaces to control the distance between the pole and smelting molten material in addition to other applications.

  1. Active control system for high speed windmills

    Science.gov (United States)

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

    1988-01-01

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

  2. Apu/hydraulic/actuator Subsystem Computer Simulation. Space Shuttle Engineering and Operation Support, Engineering Systems Analysis. [for the space shuttle

    Science.gov (United States)

    1975-01-01

    Major developments are examined which have taken place to date in the analysis of the power and energy demands on the APU/Hydraulic/Actuator Subsystem for space shuttle during the entry-to-touchdown (not including rollout) flight regime. These developments are given in the form of two subroutines which were written for use with the Space Shuttle Functional Simulator. The first subroutine calculates the power and energy demand on each of the three hydraulic systems due to control surface (inboard/outboard elevons, rudder, speedbrake, and body flap) activity. The second subroutine incorporates the R. I. priority rate limiting logic which limits control surface deflection rates as a function of the number of failed hydraulic. Typical results of this analysis are included, and listings of the subroutines are presented in appendicies.

  3. Operating Experience Insights into Pipe Failures for Electro-Hydraulic Control and Instrument Air Systems in Nuclear Power Plant. A Topical Report from the Component Operational Experience, Degradation and Ageing Programme

    International Nuclear Information System (INIS)

    Structural integrity of piping systems is important for plant safety and operability. In recognition of this, information on degradation and failure of piping components and systems is collected and evaluated by regulatory agencies, international organisations (e.g. OECD/NEA and IAEA) and industry organisations worldwide to provide systematic feedback for example to reactor regulation and research and development programmes associated with non-destructive examination (NDE) technology, in-service inspection (ISI) programmes, leak-before-break evaluations, risk-informed ISI, and probabilistic safety assessment (PSA) applications involving passive component reliability. Several OECD member countries have agreed to establish the OECD/NEA 'Component Operational Experience, Degradation and Ageing Programme' (CODAP) to encourage multilateral co-operation in the collection and analysis of data relating to degradation and failure of metallic piping and non-piping metallic passive components in commercial nuclear power plants. The scope of the data collection includes service-induced wall thinning, part through-wall cracks, through-wall cracks with and without active leakage, and instances of significant degradation of metallic passive components, including piping pressure boundary integrity. The OECD/NEA Committee on the Safety of Nuclear Installations (CSNI) acts as an umbrella committee of the Project. CODAP is the continuation of the 2002-2011 'OECD/NEA Pipe Failure Data Exchange Project' (OPDE) and the Stress Corrosion Cracking Working Group of the 2006-2010 'OECD/NEA Stress Corrosion Cracking and Cable Ageing Project' (SCAP). OPDE was formally launched in May 2002. Upon completion of the third term (May 2011), the OPDE project was officially closed to be succeeded by CODAP. SCAP was enabled by a voluntary contribution from Japan. It was formally launched in June 2006 and officially closed with an international workshop held in Tokyo in May 2010. The majority of the member organisations of the two projects were the same, often being represented by the same person. In May 2011, thirteen countries signed the CODAP 1. Term Agreement (Canada, Chinese Taipei, Czech Republic, Finland, France, Germany, Japan, Korea (Republic of), Slovak Republic, Spain, Sweden, Switzerland and the United States). The 1. Term work plan includes the preparation of Topical Reports to foster technical co-operation and to deepen the understanding of national differences in ageing management. The Topical Reports constitute CODAP Event Database and Knowledge Base insights reports and as such act as portals for future database application projects and in-depth studies of selected degradation mechanisms. Prepared in 2013 and published as NEA/CSNI/R(2014)6, a first Topical Report addressed flow accelerated corrosion (FAC) of carbon steel and low alloy steel piping. This, the second Topical Report addresses operating experience with electro-hydraulic control (EHC) and instrument air (IA) system piping. Degradation and failure of EHC or IA piping can adversely affect plant operability, and under certain circumstances lead to safety challenges. Both systems consist of significant lengths of small-diameter piping. The typical EHC system piping material is stainless steel; Type 304 or 316. Plants generally use carbon steel, copper, stainless steel, galvanised steel or combinations of two or more material types for IA system piping. The CODAP Topical Report on 'EHC and IA Piping Systems' includes a primer on the environmental and operational factors affecting the structural integrity of respective system, and evaluates service experience data as recorded in the CODAP Event Database. Also included in the report are descriptions of the national EHC and IA ageing management programme approaches and a summary of other information collected in the CODAP Knowledge Base. The report has been prepared by the CODAP Project Review Group, with support from the CODAP Operating Agent and the CODAP Knowledge Base Coordinator. There are 215

  4. 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

  5. 49 CFR 570.57 - Air brake system and air-over-hydraulic brake subsystem.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 6 2010-10-01 2010-10-01 false Air brake system and air-over-hydraulic brake... STANDARDS Vehicles With GVWR of More Than 10,000 Pounds § 570.57 Air brake system and air-over-hydraulic brake subsystem. The following requirements apply to vehicles with air brake and...

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

    DEFF Research Database (Denmark)

    Schmidt, Lasse; Andersen, Torben Ole; Pedersen, Henrik C.

    2013-01-01

    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 sec...

  7. Design of an Electro-Hydraulic System Using Neuro-Fuzzy Techniques

    CERN Document Server

    Branco, P J C

    2000-01-01

    Increasing demands in performance and quality make drive systems fundamental parts in the progressive automation of industrial processes. Their conventional models become inappropriate and have limited scope if one requires a precise and fast performance. So, it is important to incorporate learning capabilities into drive systems in such a way that they improve their accuracy in realtime, becoming more autonomous agents with some degree of intelligence. To investigate this challenge, this chapter presents the development of a learning control system that uses neuro-fuzzy techniques in the design of a tracking controller to an experimental electro-hydraulic actuator. We begin the chapter by presenting the neuro-fuzzy modeling process of the actuator. This part surveys the learning algorithm, describes the laboratorial system, and presents the modeling steps as the choice of actuator representative variables, the acquisition of training and testing data sets, and the acquisition of the neuro-fuzzy inverse-model...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-01-15

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Soli Khericha; Edwin Harvego; John Svoboda; Ryan Dalling

    2012-01-01

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

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

    International Nuclear Information System (INIS)

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

  11. 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.

  12. 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)

  13. Development of an Advanced Hydraulic Fracture Mapping System

    Energy Technology Data Exchange (ETDEWEB)

    Norm Warpinski; Steve Wolhart; Larry Griffin; Eric Davis

    2007-01-31

    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.

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

    DEFF Research Database (Denmark)

    Schmidt, Lasse; Andersen, Torben Ole; Pedersen, Henrik C.

    2013-01-01

    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 cont...

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

    OpenAIRE

    Cassan, L.; Baume, J-P.; Belaud, G.; Litrico, X.; Malaterre, P-O.; Ribot-Bruno, J.

    2011-01-01

    The article describes the hydraulic functioning of a mixed water level control hydromechanical gate present in several irrigation canals. According to the flow conditions, this automatic gate maintains the upstream level close to a target value for low flow, then it controls the downstream level close to a target, and switches back to control the upstream level to avoid overflow. Such a complex behaviour is obtained via a series of side tanks linked by orifices and weirs. We analyze this beha...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-05-29

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

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

    Science.gov (United States)

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

    2014-11-01

    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.

  18. 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)

  19. Uprated dc power system and thermal-hydraulic facilities at Columbia University. Final report

    International Nuclear Information System (INIS)

    The necessity of carrying out large scale nuclear thermal-hydraulic simulations is increasing. Such experiments call for large power sources, and to meet those requirements the D.C. power system at the Heat Transfer Research Facility of Columbia University has been upgraded to 11.5 MW. The uprated system, its installations, various subsystems, and operations are described. The thermal-hydraulic loops and their auxiliary systems which are supported by the D.C. power system are also described

  20. 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 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

  1. Global stabilisation of large-scale hydraulic networks with quantised and positive proportional controls

    DEFF Research Database (Denmark)

    Jensen, Tom NŘrgaard; Wisniewski, Rafal

    2013-01-01

    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.

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

    Science.gov (United States)

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

    2011-12-01

    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.

  3. Engineered Barrier Systems Thermal-Hydraulic-Chemical Column Test Report

    Energy Technology Data Exchange (ETDEWEB)

    W.E. Lowry

    2001-12-13

    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&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.

  4. 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

  5. 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)

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

    DEFF Research Database (Denmark)

    Schmidt, Lasse; Andersen, Torben Ole; Pedersen, Henrik C.; Bech, Michael Mřller

    2013-01-01

    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. Resu...

  7. 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)

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

    Energy Technology Data Exchange (ETDEWEB)

    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

    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).

  9. Macrocalibration in the process of hydraulic modelling of water supply systems

    OpenAIRE

    Šantl, Sašo

    2007-01-01

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

  10. Electric vehicle regenerative antiskid braking and traction control system

    Science.gov (United States)

    Cikanek, S.R.

    1995-09-12

    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.

  11. Thermal-Hydraulic Experiments and Modelling for Advanced Nuclear Reactor Systems

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-04-15

    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.

  12. Thermal-Hydraulic Experiments and Modelling for Advanced Nuclear Reactor Systems

    International Nuclear Information System (INIS)

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

  13. 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

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

    OpenAIRE

    Lipovšek, Sre?ko

    2008-01-01

    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...

  15. Development of semi-active hydraulic damper as active interaction control device to withstand external excitation

    Indian Academy of Sciences (India)

    Ming-Hsiang Shih; Wen-Pei Sung

    2014-02-01

    Semi-automatic control systems have the characteristics of being adaptable and requiring low energy. The objective of this research was to study the performance of an improved DSHD (Displacement Semi-Active Hydraulic Damper) by converting it to AIC (Active Interaction Control Device) with the addition of an accumulator. The prototype was tested using full-scale elements for examining the structural displacement, and typical responses of the interacting interface element developed in this research, the pressure variation of the pressure storage device, and the energy dissipation hysteresis loop when the structure installed with these elements is subjected to external force of various magnitude. The laboratory results confirm that the device developed in this research is capable of applying the energy dissipation characteristics of DSHD so that these elements are appropriate for developing the proposed AIC. The mutual interaction between the subordinate structure and the main structure to be protected is capable of transforming the quake energy applied to the main structure to the subordinate structure so that the objective of minimizing the deformation of main structural can be achieved.

  16. 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)

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

    DEFF Research Database (Denmark)

    Schmidt, Lasse; Andersen, Torben Ole

    2014-01-01

    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, on the 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.

  18. Hydraulic simulation of the systems of a nuclear power plant for charges calculation in piping

    International Nuclear Information System (INIS)

    This work presents a general description of the methodology used by the ENACE S.A. Fluids Working Group for hydraulics simulation of a nuclear power plant system for the calculation charges in piping. (Author)

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

    Directory of Open Access Journals (Sweden)

    Ali M. Yousef

    2012-08-01

    Full Text Available 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 and system parameter changes. Further, comparative studies between the conventional PID control and proposed efficient fuzzy logic load frequency control are included on the simulation results. Programs Matlab software are developed for simulation. The digital results prove the power of the present fuzzy load-frequency controller over the conventional. PID controller in terms of fast response with less overshoot and small settling time.

  20. 46 CFR 58.30-10 - Hydraulic fluid.

    Science.gov (United States)

    2010-10-01

    ...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...

  1. Modelling and simulation of a hydraulic power assisted steering system through Bond Graphs

    OpenAIRE

    Viana, L.G.; Romero Rey, Gregorio; Maroto Ibáńez, Joaquín; Félez Mindán, Jesús

    2010-01-01

    The hydraulic power assisted steering (HPAS) system is one of the most sensitive vehicle interfaces to the driver perception. Comfort and performance parameters such as ride, handling, tactile transfer functions and overall noise levels are directly affected by its performance. The modeling of a HPAS system using the bond graph technique makes possible the combination of hydraulic and mechanical components. This allows physical and design variables such as fluid compressibility and hoses diam...

  2. Fault Diagnosis for Nonlinear Hydraulic-Mechanical Drilling Pipe Handling System

    DEFF Research Database (Denmark)

    Choux, Martin; Blanke, Mogens

    2011-01-01

    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 gi...

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

    International Nuclear Information System (INIS)

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

  4. 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

  5. Hydraulic relationships between shallow groundwater sub-systems discharging to surface water bodies and underlying regional systems

    Energy Technology Data Exchange (ETDEWEB)

    Modica, E.

    1993-01-01

    Hypothetical flow models and a flow simulation of the Upper Rancocas watershed system in New Jersey were used to characterize the boundary zone separating stream sub-system flow and regional flow, and to determine the flow patterns within stream sub-systems. Estimates of flow in three-dimensional aquifer systems consisting of regional and stream sub-system flow regimes were made with numerical flow solutions and particle tracking analysis. Hydraulic parameters that affect stream system flow patterns were systematically modified in order to evaluate cause-and-effect relations and to determine the degree to which parameters can influence flow in the system. Stream sub-system geometry and its flow patterns are largely controlled by the quantity and distribution of stream discharge. The relative amount and location of discharge along a stream channel is in turn affected by variations in anisotropy, aquifer thickness, recharge rates, streambed elevation, and drainage density. The bounding surface' is an interaction zone between the stream sub-system and the adjacent flow system, the form of which is sensitive to system boundaries and hydraulic properties of the aquifer and stream sub-system. Regional flow is restricted in thin aquifer systems. Stream source areas in thin aquifers tend to be more extensive. Thin systems limit the development of flow to remote or major regional sinks that serve as common discharge outlets for the system. Thick aquifers allow for development of deeper flow systems under local stream sub-systems. Streams are line-sinks that induce complex flow patterns in a flow field whereby flow from near and far source areas are drawn into common discharge zones. The age range of groundwater that discharges along the stream varies as a function of distance downstream from the start-of-flow. The highest age ranges occur near the stream terminus.

  6. Discrete Learning Control with Application to Hydraulic Actuators

    DEFF Research Database (Denmark)

    Andersen, Torben Ole; Pedersen, Henrik Clemmensen; Hansen, Michael R.

    2015-01-01

    In this paper the robustness of a class of learning control algorithms to state disturbances, output noise, and errors in initial conditions is studied. We present a simple learning algorithm and exhibit, via a concise proof, bounds on the asymptotic trajectory errors for the learned input and the corresponding state and output trajectories. Furthermore, these bounds are continuous functions of the bounds on the initial condition errors, state disturbance, and output noise, and the bounds are ze...

  7. The Control System Modeling and The Mechanical Structure Analysis For EMCVT

    OpenAIRE

    Zhang, Lei; Cong, Xiaomei; Hujian Pan; Zuge CAI; Xiumin YANG

    2013-01-01

    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...

  8. Hydraulic Capsule Pipeline Transport System : Technical Charakteristics, Modelling and Applications.

    Czech Academy of Sciences Publication Activity Database

    Berman, V.; Vlasák, Pavel

    Wroclaw : Publishers of Agricultural Univeristy of Wroclaw, 2002 - (Sobota, J.; Verhoeven, R.), s. 259-267 ISBN 83-87866-34-2. [International Conference on Transport and Sedimentation of Solid Particles /11./. Ghent (BE), 09.09.2002-12.09.2002] R&D Projects: GA AV ?R IBS2060007 Keywords : hydraulic capsule pipelining * flow parameters calculation * experimental results Subject RIV: BK - Fluid Dynamics

  9. RESEARCH ON HYDRAULIC SERVO AMPLIFIERS USED IN MARINE SYSTEMS

    Directory of Open Access Journals (Sweden)

    Ali BEAZIT

    2010-06-01

    Full Text Available This paper presents numerical simulations for the mecano-hydraulic servoamplifier with a special kind of distributor. This distributor has different covering for the admission and evacuation flow. The purpose of this kind of distributor is to diminuate the high frequency auto-oscillations of the servoamplifier.

  10. RESEARCH ON HYDRAULIC SERVO AMPLIFIERS USED IN MARINE SYSTEMS

    OpenAIRE

    BEAZIT Ali; Gheorghe SAMOILESCU; Sander CALISAL; Adriana SPORIS

    2010-01-01

    This paper presents numerical simulations for the mecano-hydraulic servoamplifier with a special kind of distributor. This distributor has different covering for the admission and evacuation flow. The purpose of this kind of distributor is to diminuate the high frequency auto-oscillations of the servoamplifier.

  11. 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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-12-31

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

  13. Algorithm for automatic manufacturing control of general hydraulic surface.

    Czech Academy of Sciences Publication Activity Database

    Rössler, Tomáš; Hrabovský, Miroslav

    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

  14. Nuclear reactor with hydraulic operation of the control rod clusters

    International Nuclear Information System (INIS)

    The reactor comprises a vessel closed by a slab and a core containing fuel assemblies. Two different types of fuel rod clusters are used; the vessel is fitted with an internal structure above the core provided with guide elements for the clusters. The mechanism of the first cluster type is a vertical cylinder fitted with the internal structure of the reactor, which together with a piston encloses operating chambers from which a group of rods is suspended, being part of or forming the actual cluster. The operating chamber is connected to chamber vice pipes and control valve, the pressure in chamber being less than the pressure in the vessel

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

    Directory of Open Access Journals (Sweden)

    Enrique Vidal

    2013-08-01

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

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

    DEFF Research Database (Denmark)

    Hansen, Rico Hjerm; Kramer, Morten

    2013-01-01

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Stoll, U.

    2000-07-01

    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.)

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

    OpenAIRE

    SONG Yunpu

    2012-01-01

    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 equilibri...

  19. Improving the Hydraulic Performance of Stormwater Infiltration Systems in Clay Tills

    DEFF Research Database (Denmark)

    Bockhorn, Britta

    2015-01-01

    Many cities of the Northern Hemisphere are covered by low permeable clay tills, which pose a challenge for stormwater infiltration practices. However, clay tills are amongst the most heterogeneous types of sediments and hydraulic conductivities can vary by several orders of magnitude. This PhD study was initiated with the objective to test and evaluate if the hydraulic performance of stormwater infiltration systems can be significantly improved if the site-specific geological heterogeneity is in...

  20. Hydraulic characteristics of the N Reactor core and reactor cooling system

    International Nuclear Information System (INIS)

    In conjunction with the NUSAR program, the need was recognized for well substantiated pressure drop correlations for the N Reactor core to support in-depth safety analysis consistent with currently-available technology. Additionally, it was considered desirable to reconfirm the hydraulic characteristics of the reactor coolant system in the light of improved understanding of the hydraulic features of the current reactor fuel loading. The report summarizes the results of laboratory tests and analysis accomplished to meet the above objectives

  1. Speed-variable Switched Differential Pump System for Direct Operation of Hydraulic Cylinders

    DEFF Research Database (Denmark)

    Schmidt, Lasse; Roemer, Daniel Beck; Pedersen, Henrik Clemmensen; Andersen, Torben O.

    2015-01-01

    Efforts to overcome the inherent loss of energy due to throttling in valve driven hydraulic systems are many, and various approaches have been proposed by research communities as well as the industry. Recently, a so-called speed-variable differential pump was proposed for direct drive of hydraulic differential cylinders. The main idea was here to utilize an electric rotary drive, with the shaft interconnected to two antiparallel fixed displacement gear pumps, to actuate a differential cylinder. ...

  2. Realization of tin freezing point using a loop heat pipe-based hydraulic temperature control technique

    Science.gov (United States)

    Joung, Wukchul; Gam, Kee Sool; Kim, Yong-Gyoo

    2015-10-01

    In this work, the freezing point of tin (Sn FP) was realized by inside nucleation where the supercooling of tin and the reheating of the sample after the nucleation were achieved without extracting the cell from an isothermal apparatus. To this end, a novel hydraulic temperature control technique, which was based on the thermo-hydraulic characteristics of a pressure-controlled loop heat pipe (LHP), was employed to provide a slow cooling of the sample for deep supercooling and fast reheating after nucleation to minimize the amount of initial freeze of the sample. The required temperature controls were achieved by the active pressure control of a control gas inside the compensation chamber of the pressure-controlled LHP, and slow cooling at??-0.05 K min-1 for the deep supercooling of tin and fast heating at 2 K min-1 for reheating the sample after nucleation was attained. Based on this hydraulic temperature control technique, the nucleation of tin was realized at supercooling of around 19 K, and a satisfactorily fast reheating of the sample to the plateau-producing temperature (i.e. 0.5 K below the Sn FP) was achieved without any temperature overshoots of the isothermal region. The inside-nucleated Sn FP showed many desirable features compared to the Sn FP realized by the conventional outside nucleation method. The longer freezing plateaus and the better immersion characteristics of the Sn FP were obtained by inside nucleation, and the measured freezing temperature of the inside-nucleated Sn FP was as much as 0.37 mK higher than the outside-nucleated Sn FP with an expanded uncertainty of 0.19 mK. Details on the experiment are provided and explanations for the observed differences are discussed.

  3. 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)

  4. 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 characterising 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 characterise 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. (author) 3 refs., 13 figs

  5. Hydraulic system with several stages for prestressed bolts and gudgeon pins

    International Nuclear Information System (INIS)

    This invention relates to a hydraulic system to bring bolts and gudgeon pins into a prestressed state so that the nut may be tightened in this position. In the nuclear industry where it is necessary to place a large number of bolts or pins into significant prestress to ensure the closing of reactor vessel closures, several stages each comprising a piston and a cell of analogous configuration have to be superimposed in the same hydraulic stretcher. The description is given of a hydraulic prestressed bolt and gudgeon pin stretcher with several stages in which the deformations of the various components of each stage are significantly equal and of a set of several hydraulic stretchers for simultaneously prestressing multiple bolts and pins as well as the easy and simultaneous handling of this set

  6. 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

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

    Science.gov (United States)

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

    2015-03-01

    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 (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.

  8. 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

  9. Apparatus for measuring friction of hydraulic control rod drives in nuclear reactors

    International Nuclear Information System (INIS)

    An apparatus is disclosed which measures forces resisting the movement of pistons in a control rod drive mechanism in a nuclear reactor and which includes pressure sensing means and further includes hydraulic circuitry to divert pressurized fluid from a normal operating conduit to a selected shunt conduit containing a valve having a particular fluid control characteristic, said shunt conduit directing the fluid to a selected piston to move said piston and said pressure sensing means measuring the pressure of the fluid during the motion of said piston to give an indication of the force needed to achieve such motion

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

    International Nuclear Information System (INIS)

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

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

    OpenAIRE

    Bleninger, Tobias

    2007-01-01

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

  12. An expert system for hydraulic excavator and truck selection in surface mining

    Scientific Electronic Library Online (English)

    C., Kirmanli; S.G., Ercelebi.

    2009-12-01

    Full Text Available The purpose of this paper is to develop an expert system for hydraulic excavator and truck selection in surface mining. Hydraulic excavators and trucks are finding increasing applications in mining operations. Hydraulic excavators are extensively used especially when bringing electricity to rural ar [...] eas is difficult and for small-scale mining. This paper describes an expert system, which selects the optimum hydraulic excavator truck configuration such that unit production cost is minimized and technical constraints such as geological, geotechnical and mining constraints are satisfied. The system has four modules: user interface, rules and an methods, databases and output module. The expert system in this study is developed within KappaPC shell. It supports object-orientated technology for the MS Windows environment. The software provides a very useful tool to practitioners, saving time and cost. Equipment selection is a recurring and expensive problem of mine planning and often involves interdisciplinary experts from different fields. It is very difficult and expensive to bring together all these experts. The capabilities of the expert system developed are illustrated in the paper. The software overcomes the difficulties of selecting the proper equipment for surface mining operations, which is very important, and results in substantial savings. Equipment databases for hydraulic excavators with 15-59 yd3 capacities and trucks with 35-360 tons are constructed and these databases are used to select the proper configuration. A case study is carried out for Soma Surface Coal mines in Turkey.

  13. Mechanical Engineering Design Project report: Enabler control systems

    Science.gov (United States)

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

    1992-01-01

    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.

  14. 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.

  15. Hydraulic design optimization for hollow fibre filter system

    International Nuclear Information System (INIS)

    An analytical model has been developed to describe hydraulic characteristics of a hollow fiber filter (HFF) for the purification of condensate of BWR nuclear power plants. Based on this, a module structure was proposed to minimize pressure drop at the beginning of its operation. The mechanism of iron ion crystallization on the HFF surface was clarified and a countermeasure against it was developed. Taking account of this effect, a simulation code was developed to predict the pressure drop trend in the course of the HFF operation. (author)

  16. Prosthetic Knee Systems

    Science.gov (United States)

    ... friction systems are less effective than hydraulic systems. Hydraulic control. These systems: use liquid (usually silicone oil) to ... to “learn” the user’s walking characteristics have timing, force, ... the fluid control system accordingly take less effort to control timing, ...

  17. Design and testing of the reactor-internal hydraulic control rod drive for the nuclear heating plant

    International Nuclear Information System (INIS)

    A hydraulically driven control rod is being developed at Kraftwerk Union for integration in the primary system of a small nuclear district heating reactor. An elaborate test program, under way for --3 yr, was initiated with a plexiglass rig to understand the basic principles. A design specification list was prepared, taking reactor boundary conditions and relevant German rules and regulations into account. Subsequently, an atmospheric loop for testing of components at 20 to 900C was erected. The objectives involved optimization of individual components such as a piston/cylinder drive unit, electromagnetic valves, and an ultrasonic position indication system as well as verification of computer codes. Based on the results obtained, full-scale components were designed and fabricated for a prototype test rig, which is currently in operation. Thus far, all atmospheric tests in this rig have been completed. Investigations under reactor temperature and pressure, followed by endurance tests, are under way. All tests to date have shown a reliable functioning of the hydraulic drive, including a novel ultrasonic position indication system

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

    Directory of Open Access Journals (Sweden)

    P. Athanasatos

    2013-01-01

    Full Text Available In this study, a model of a high pressure hydraulic system was developed using the bond graph method to investigate the effect of the internal leakage of its main components (pump, cylinder and 4/2 way valve on the operational characteristics of the system under various loads. All the main aspects of the hydraulic circuit (like the internal leakages, the compressibility of the fluid, the hydraulic pressure drop, the inertia of moving masses and the friction of the spool were taken into consideration. The results of this modeling were compared with the experimental data taken from the literature and from an actual test platform installed in the laboratory. Modeling and experimental data curves correlate very well in form, magnitude and response times for all the systemâ??s main parameters. This proves that the present method can be used to accurately model the response and operation of hydraulic systems and can thus be used for operational fault diagnosis in many cases, especially in simulating fault scenarios when the defective component is not obvious. This is very important in industrial production systems where unpredictable shutdowns of the hydraulic machinery have a considerable negative economic impact on cost.

  19. Theoretical Analysis and Bench Tests of a Control-Surface Booster Employing a Variable Displacement Hydraulic Pump

    Science.gov (United States)

    Mathews, Charles W.; Kleckner, Harold F.

    1947-01-01

    The NACA is conducting a general investigation of servo-mechanisms for use in powering aircraft control surfaces. This paper presents a theoretical analysis and the results of bench tests of a control-booster system which employs a variable displacement hydraulic pump. The booster is intended for use in a flight investigation to determine the effects of various booster parameters on the handling qualities of airplanes. Such a flight investigation would aid in formulating specific requirements concerning the design of control boosters in general. Results of the theoretical analysis and the bench tests indicate that the subject booster is representative of types which show promise of satisfactory performance. The bench tests showed that the following desirable features were inherent in this booster system: (1) No lost motion or play in any part of the system; (2) no detectable lag between motion of the contra1 stick and control surface; and (3) Good agreement between control displacements and stick-force variations with no hysteresis in the stick-force characteristics. The final design configuration of this booster system showed no tendency to oscillate, overshoot, or have other undesirable transient characteristics common to boosters.

  20. 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.

  1. 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

  2. Quick-response servo amplifies small hydraulic pressure differences

    Science.gov (United States)

    Wiegard, D. E.

    1966-01-01

    Hydraulic servo, which quickly diverts fluid to either of two actuators, controls the flow rates and pressures within a hydraulic system so that the output force of the servo system is independent of the velocity of the mechanism which the system actuates. This servo is a dynamic feedback control device.

  3. FEEDBACK LINEARISATION APPLIED ON A HYDRAULIC

    DEFF Research Database (Denmark)

    Andersen, Torben Ole; Hansen, Michael Rygaard; Pedersen, Henrik C.; Conrad, Finn

    2005-01-01

    Generally most hydraulic systems are intrensically non-linear, why applying 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 developing and applying several different feedback linearisation (FL) controllers to the individual servo actuators in a hydraulically driven servo robot to evaluate and compare their possiblitie...

  4. Fault Diagnosis for Nonlinear Hydraulic-Mechanical Drilling Pipe Handling System

    DEFF Research Database (Denmark)

    Choux, Martin; Blanke, Mogens

    2011-01-01

    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.

  5. Hydraulic design optimization for hollow fiber filter system

    International Nuclear Information System (INIS)

    An analytical model has been developed to describe hydraulic characteristics of a hollow fiber membrane filter (HFF) for condensate purification in BWR power plants. Using this model, a module structure was proposed to minimize pressure drop at the beginning of HFF operation. That is, given flow rate of a module, both dimensions of the inner diameter and the length of a single fiber membrane were designed to have optimal values, giving minimum volume for the module. The mechanism of Fe ion crystallization on HFF surface which determines operation life time was clarified and a countermeasure against it was developed. Precoating of amorphous iron crud effectively inhibited crystallization. Taking account of the crystallization, a simulation code was developed to predict pressure drop trend in the course of HFF operation. (author)

  6. Open upper plenum of LOF thermal hydraulics and inherent control rod insertion

    International Nuclear Information System (INIS)

    In liquid-metal reactor (LMR) hypothetical transients for which normal scram is postulated not to occur, the thermal expansion of the control rod drivelines (CRDs) as they are washed by the hotter core effluent tends to insert the control assemblies (CAs) further into the core, thereby providing negative reactivity. A number of concepts to enhance the heatup-induced elongation of drivelines is being proposed involving both design features of the drivelines as well as flow control features of the drivelines and the upper internals structure (UIS). Reported here are the results of an analysis in which the COMMIX-1A computer code was used to investigate the three-dimensional thermal-hydraulic behavior in the upper plenum of a 425-MW(t) pool-type LMR during a loss-of-flow (LOF) transient and its influence on the driveline heatup and expansion. The calculations consider an open plenum geometry, which does not incorporate a UIS or CRD shroud tubes such that the drivelines are directly exposed to the multidimensional plenum flow. The objective of the present work is to define reference cases for inherent CRD insertion in which thermal-hydraulic features that might enhance the driveline heatup but, on the other hand, whose effects may be quantitatively sensitive to design details are completely absent

  7. Analysis criteria for control of pipes exposed to thermo-hydraulic loading

    International Nuclear Information System (INIS)

    The objective was to develop criteria and parameters suited for control of stress convergence in piping exposed to thermo-hydraulic loading. A pipe segment model was derived based on an axisymmetric shell formulation and a beam formulation. For the contained fluid an acoustic formulation was used. The implemented FEM-formulation of the pipe segment was verified by comparison with documented analytical solutions. For the pipe structure part Mindlin shell theory was used for verification. Based on the FEM-formulation stress convergence parameters were derived. The derived parameters correspond to the parameter effective modal mass, which is widely used in connection with base motion excited structures. The parameters were derived both for the coupled elasto-acoustic procedure and for the traditional uncoupled 2-step procedure based on derived control volume force signals. In order to control the stress convergence parameters a test model of a piping system was used. Response signals of different section forces and moments were computed for a rapid valve closure load. Convergence of computed response signals were compared to the estimated convergence parameters. The derived convergence parameters are found to be a reliable tool in order to determine an adequate time step and modal base for stress analysis in the pipe. The test computations also show that stress convergence may be achieved by use of a much longer time step and a courser element discretization than a traditional approach, based on the load signal only, will indicate. The convergence of pure axial stresses and shear stresses due to translational forces is slower than for bending moments. However this will not harm fulfilment of stress acceptance criteria in the piping but may be a matter of concern in connection with stress analysis of the pipe supporting structure. A limited study was also performed about the influence of the structural damping value on the dynamic stress response. The coupled formulation, FSI, was used. The influence was found to be weak. The reason for this is the impulse type of loading. It is not found meaningful to study the damping influence when use of the traditional uncoupled 2-step procedure. A possible resonant behaviour of the structural response, when use of such a procedure, is found to be non physical and an effect of applied method only

  8. Thermal-hydraulic studies on self actuated shutdown system for Japan Sodium-cooled Fast Reactor

    International Nuclear Information System (INIS)

    The self-actuated shutdown system (SASS), which is selected for Japan Sodium-cooled Fast Reactor (JSFR), is a passive reactor shutdown system utilizing a Curie point electromagnet (CPEM). With CPEM, an excessive fuel outlet temperature rise is sensed and the control rods are released into the core, and the reactor can be shutdown. Therefore it is important for feasibility of SASS to be established by assuring a quick response of CPEM to the coolant temperature rise. In this paper, a device named 'flow collector', which collects flows discharged from six fuel subassemblies surrounding CPEM backup control rods, has been proposed to ensure a shorter response time. Three-dimensional thermal-hydraulic analysis has been performed to evaluate the response time of CPEM with the flow collector, and it is confirmed that the coolant discharged from the fuel subassemblies flows into CPEM with high velocity and the response time of CPEM can be significantly shortened. Based on this analysis, the safety analysis has been carried out, confirming that the maximum temperatures of core and coolant are lower than those imposed by the safety criteria, and feasibility of SASS is assured. (author)

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

    Directory of Open Access Journals (Sweden)

    Kormann A. C. M.

    2003-01-01

    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/mł. 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.

  10. Hydraulic and nutritional feedback controls surface patchiness of biological soil crusts at a post-mining site.

    Science.gov (United States)

    Fischer, Thomas; Gypser, Stella; Subbotina, Maria; Veste, Maik

    2015-04-01

    In a recultivation area located in Brandenburg, Germany, five types of biocrusts (initial BSC1, developed BSC2 and BSC3, mosses, lichens) and non-crusted mineral substrate were sampled on tertiary sand deposited in 1985-1986 to investigate hydrologic properties of crust patches. It was the aim of the study to demonstrate that (I) two types of BSC with alternative nutritional and hydraulic feedback modes co-exist in one area and that (II) these feedback modes are synergic. The sites to sample were selected by expertise, trying to represent mixed sites dominated by mosses, by lichens, and by visually in the field observable surface properties (colour and crust thickness) for the non-crusted substrate and BSC1 to 3. The non-crusted samples contained minor incrustations of the lichen Placynthiella oligotropha, young leaflets of the moss Ceratodon purpureus, as well as very sparsely present individuals of the green algae Ulothrix spec., Zygogonium spec. and Haematococcus spec. The sample BSC1 was not entirely covered with microphytes, crust patches were smooth, and P. oligotropha was observed to develop on residues of C. purpureus and on unspecified organic detritus. BSC2 covered the surface entirely and was dominated by P. oligotropha and by Zygogonium spec. The sample BSC3 consisted of pad-like patches predominantly growing on organic residues. The moss sample was dominated by C. purpureus and Zygogonium spec. growing between the moss stemlets directly on the mineral surface, the lichen sample was dominated by Cladonia subulata with sparsely scattered individuals of C. purpureus. Hierarchical cluster analysis revealed that BSC2 was floristically and chemically most similar to the moss crust, whereas BSC3 was floristically and chemically most similar to the lichen crust. Crust biomass was lowest in the non-crusted substrate, increased to the initial BSC1 and peaked in the developed BSC2, BSC3, the lichens and the mosses. Water infiltration was highest on the substrate, and decreased to BSC2, BSC1 and BSC3. Non-metric multidimensional scaling revealed that the lichens and BSC3 were associated with water soluble nutrients (NO3, NH4, K, Mg, Ca) and with pyrite weathering products (pH, SO4), thus representing a high nutrient low hydraulic feedback mode. The mosses and BSC2 represented a low nutrient high hydraulic feedback mode. These feedback mechanisms were considered as synergic, consisting of run-off generating (low hydraulic) and run-on receiving (high hydraulic) BSC patches. Three scenarios for BSC succession were proposed. (1) Initial BSCs sealed the surface until they reached a successional stage (represented by BSC1) from which the development into either of the feedback modes was triggered, (2) initial heterogeneities of the mineral substrate controlled the development of the feedback mode, and (3) complex interactions between lichens and mosses occurred at later stages of system development. It was concluded that, irrespective of successional pathways, two synergic feedback mechanisms contributed to the generation of self-organized surface patchiness. Such small-scale microsite differentiation with different BSCs has important implications for the vegetation in post-mining sites. Reference Fischer, T., Gypser, S., Subbotina, M., Veste, M. (2014) Synergic hydraulic and nutritional feedback mechanisms control surface patchiness of biological soil crusts on tertiary sands at a post-mining site. Journal of Hydrology and Hydromechanics 62(4):293-302

  11. Electric vehicle regenerative antiskid braking and traction control system

    Science.gov (United States)

    Cikanek, Susan R. (Wixom, MI)

    1995-01-01

    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.

  12. Teaching Thermal Hydraulics and Numerical Methods: An Introductory Control Volume Primer

    International Nuclear Information System (INIS)

    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

  13. Underwater manipulator's kinematic analysis for sustainable and energy efficient water hydraulics system

    Science.gov (United States)

    Hassan, Siti Nor Habibah; Yusof, Ahmad Anas; Tuan, Tee Boon; Saadun, Mohd Noor Asril; Ibrahim, Mohd Qadafie; Nik, Wan Mohd Norsani Wan

    2015-05-01

    In promoting energy saving and sustainability, this paper presents research development of water hydraulics manipulator test rig for underwater application. Kinematic analysis of the manipulator has been studied in order to identify the workspace of the fabricated manipulator. The workspace is important as it will define the working area suitable to be developed on the test rig, in order to study the effectiveness of using water hydraulics system for underwater manipulation application. Underwater manipulator that has the ability to utilize the surrounding sea water itself as the power and energy carrier should have better advantages over sustainability and performance.

  14. Thermal-hydraulic analysis of spallation target in accelerator driven sub-critical system

    International Nuclear Information System (INIS)

    The spallation target is located in the center of an accelerator driven sub-critical system (ADS), which produces neutron source for nuclear transmutation. Based on the analysis of the thermal-hydraulic demands for spallation target, lead-bismuth eutectic (LBE) was chosen as the spallation target and the coolant for the ADS. MCNP code was used to calculate the deposition heat in the spallation target, and the CFD code FLUENT was employed to calculate the thermal-hydraulic behavior in the spallation target zone. Different design parameters as well as different window shapes were analyzed in order to find their effects to the temperature distribution and velocity distribution, and the suitable design options were found to meet the thermal-hydraulic requirements. (authors)

  15. 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)

  16. Stability analysis of supercritical water cooled reactor thermal-hydraulic system based on Nyquist criterion

    International Nuclear Information System (INIS)

    Aiming at the simplified model of supercritical water cooled reactor thermal-hydraulic system, small perturbation linearization and Laplace transform method were adopted to linearize the nonlinear thermal-hydraulic system conservation equations. Then the closed-loop system transfer function was deduced. Matlab code was used to analyze and simulate the closed-loop system and obtain the stability boundary map of the closed-loop system, and the effects of reactor core inlet flow velocity, heating length, gravity acceleration and inlet throttling coefficient on the system stability boundary were analyzed finally. The results show that if the reactor core inlet flow rate, the heating section length, and the gravity acceleration increase, the stability of the system will be better, and however the inlet throttling coefficient rarely affects the stability boundary. (authors)

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

    Science.gov (United States)

    Dade County Public Schools, Miami, FL.

    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…

  18. Theoretic analysis for static characteristic of servo-tube guided hydraulic control rod driving mechanism

    International Nuclear Information System (INIS)

    The analysis and calculation of static characteristic were carried out for servo tube guided hydraulic control rod driving mechanism. The static holding flow rate and its variation law with temperature were acquired. The results indicate that the static holding flow rate needed is very small in steady working range of variable throttle orifice. The liquid density decreases with the increase of temperature, and then the static holding flow rate increases accordingly. In inclining condition, the range of static holding flow rate is augmented and the holding characteristic of control rod is more stable. Therefore, the resistance ability to perturbation is much stronger and is conformable to the criterion of nautical nuclear power device. (authors)

  19. Handbook of hydraulic fluid technology

    CERN Document Server

    Totten, George E

    2011-01-01

    ""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

  20. Hardware-in-the-loop of Simulation for a Hydraulic Antilock Brake System

    OpenAIRE

    Ayman A. Aly

    2013-01-01

    Hardware-In-the-Loop (HIL) of simulation policy is used as a rapid and economical tool for developing automotive systems effectively and for dangerous situations tests such as extreme road conditions or high travelling speeds. A method for building a HIL of simulation a hydraulic Antilock Braking System (ABS) based on MATLAB/Simulink is presented in this paper. The system is implemented for research purposes as well as for the application in educational process. It can help the user heighteni...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-02-01

    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.

  2. 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.

  3. Magnetohydrodynamic control of current-carrying fluid flow in hydraulic branching

    International Nuclear Information System (INIS)

    Magnetodynamic installations with principle of operation, which is based on interaction between induced A.C. and alternating excitation field, are widespread in metallurgy for transportation of liquid metal. One unexplored mode of operation of these installations is asymmetric mode, which gives a possibility to redistribute current-carrying fluid flow in zone of hydraulic branching. Asymmetric modes of operation of these installations are widely used in metallurgy and in foundry at independent control of two liquid metal flows, which are gone out from one reservoir, e.g. portion pouring of metal from a furnace and continuous metal stirring in furnace's bath. In this work, numerical investigation of electromagnetic and hydrodynamic processes in working zone of the magnetodynamic installations has been carried out. Typical patterns of distribution of electromagnetic forces, velocities and pressures have been obtained for different relations between current phases and excitation field phases such that differential pressure in hydraulic canals reaches in maximum value. Results of the numerical investigation are in a good agreement with results of the experiments carried out under laboratory condition for transparent fluid and molten gallium

  4. A Hydraulic Motor-Alternator System for Ocean-Submersible Vehicles

    Science.gov (United States)

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

    2012-01-01

    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.

  5. The hydraulic geometry of narrow and deep channels; evidence for flow optimisation and controlled peatland growth

    Science.gov (United States)

    Nanson, Rachel A.; Nanson, Gerald C.; Huang, He Qing

    2010-04-01

    At-a-station and bankfull hydraulic geometry analyses of peatland channels at Barrington Tops, New South Wales, Australia, reveal adjustments in self-forming channels in the absence of sediment load. Using Rhodes ternary diagram, comparisons are made with hydraulic geometry data from self-forming channels carrying bedload in alluvial settings elsewhere. Despite constraints on channel depths caused at some locations by the restricted thickness of peat, most stations have cohesive, near-vertical, well-vegetated banks, and width/depth (w/d) ratios of ? 2 that are optimal for sediment-free flow. Because banks are strong, resist erosion and can stand nearly vertical, and depth is sometimes constrained, adjustments to discharge are accommodated largely by changes in velocity. These findings are consistent with the model of maximum flow efficiency and the overarching least action principle in open channels. The bankfull depth of freely adjusting laterally active channels in clastic alluvium is well known to be related to the thickness of floodplain alluvium and a similar condition appears to apply to these swamps that grow in situ and are formed almost entirely of organic matter. The thickness of peat in these swamps rarely exceeds that required to form a bankfull channel of optimum w/d ratio for the transport of sediment-free water. Swamp vegetation is highly dependent on proximity to the water table. To maintain a swamp-channel and associated floodplain system, the channels must flow with sufficient water much of the time; they not only offer an efficient morphology for flow but do so in a way that enables bankfull conditions to occur many times a year. They also prevent the swamp from growing above a level linked to the depth of the channel. Once the channel attains the most efficient cross section, further growth of the swamp vertically is restricted by enhanced flow velocities and limited flow depths. This means that the volume of peat in such swamps is determined by the hydraulic efficiency of their channels. The development and maintenance of the hydraulic geometry of these swamp channels is biogeomorphic and biohydraulic in nature and yet accords to the same optimising principles that govern the formation of self-adjusting channels and floodplains in clastic alluvium.

  6. Development and verification of a thermo-hydraulic simulation code for systems transient in 'Monju' (COPD code)

    International Nuclear Information System (INIS)

    Large system simulation codes are needed for design and safety analysis. A thermal-hydraulic simulation code for systems transient in ''Monju'' (COPD code) was developed and verified with experimental data from an experimental LMFBR ''Joyo'', 50 MWt steam generator test facility and scaled test sections of reactor vessel plenum. This paper summarizes numerical models of this code and their verifications with experimental data. Especially, a simplified analytical model to predict the transient behavior in a reactor vessel plenum is presented in detail, since this behavior has an important effect that must be taken into account in a plant thermal transient, while the reactor is tripped. The COPD is applied to design and safety analysis in ''Monju'' as follows ; (1) Safety analysis with regard to core cooling in anticipated incidents. (2) Plant thermo-hydraulic analysis for setting the design condition in thermal stress analysis and evaluation of components and pipings. (3) Control performance analysis on plant operation for design and evaluation of plant control system. Each of the above analyses requires different predictions of plant response to be analyzed. Therefore, appropriate models and input data are used in the design and evaluation according to the purpose of the analysis. This code was developed and verified under a contract with PNC. (author)

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

    International Nuclear Information System (INIS)

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

  8. 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

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

    International Nuclear Information System (INIS)

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

  10. Modeling and simulation of hydrostatic transmission system with energy regeneration using hydraulic accumulator

    International Nuclear Information System (INIS)

    A new hydraulic closed-loop hydrostatic transmission (HST) energy-saving system is proposed in this paper. The system improves the efficiency of the primary power source. Furthermore, the system is energy regenerative, highly efficient even under partial load conditions. It can work in either a flow or pressure coupling configuration, allowing it to avoid the disadvantages of each configuration. A hydraulic accumulator, the key component of the energy regenerative modality, can be decoupled from or coupled to the HST circuit to improve the efficiency of the system in low-speed, high-torque situations. The accumulator is used in a novel way to recover the kinetic energy without reversion of fluid flow. Both variable displacement hydraulic pump /motors are used when the system operates in the flow coupling configuration so as to enable it to meet the difficult requirements of some industrial and mobile applications. Modeling and a simulation were undertaken with regard to testing the primary energy sources in the two configurations and recovering the energy potential of the system. The results indicated that the low efficiency of traditional HSTs under partial load conditions can be improved by utilizing the pressure coupling configuration. The round-trip efficiency of the system in the energy recovery testing varied from 32% to 66% when the losses of the load were taken into account

  11. 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)

  12. Investigation of a Digital Hydraulic Actuation System on an Excavator Arm

    OpenAIRE

    Dell'Amico, Alessandro; Carlsson, Marcus; Norlin, Erik; Sethson, Magnus

    2013-01-01

    Digital hydraulics is an ongoing trend that offers many interesting advantages and possibilities. Digital refers to that the system output is discrete, e.g. using an on/off valve with only discrete values or a finite amount of flow steps available. The advantages mentioned when compared to analogue systems are better performance, robust and fault tolerant, and amplitude independent bandwidth. On the other side noise and pressure pulsations must be handled, the physical size can be a problem, ...

  13. Advanced model structures applied to system identification of a servo- hydraulic test rig

    Directory of Open Access Journals (Sweden)

    P. Czop

    2010-07-01

    Full Text Available Purpose: This paper deals with a method for the parametric system identification of a nonlinear system to obtain its parametric representation using a linear transfer function. Such representation is applicable in off-line profile correction methods minimizing the error between a reference input signal and a signal performed by the test rig. In turn, a test signal can be perfectly tracked by a servo-hydraulic test rig. This is the requirement in massive production where short test sequences are repeated to validate the products.Design/methodology/approach: A numerical and experimental case studies are presented in the paper. The numerical study presents a system identification process of a nonlinear system consisting of a linear transfer function and a nonlinear output component, being a static function. The experimental study presents a system identification process of a nonlinear system which is a servo-hydraulic test rig. The simulation data has been used to illustrate the feasibility study of the proposed approach, while the experimental data have been used to validate advanced model structures under operational conditions.Findings: The advanced model structures confirmed their better performance by means of the model fit in the time domain.Research limitations/implications: The method applies to analysis of such mechanical and hydraulic systems for which measurements are corrupted by residual harmonic disturbances resulting from system nonlinearities.Practical implications: The advanced model structures are intended to be used as inverse models in off-line signal profile correction.Originality/value: The results state the foundation for the off-line parametric error cancellation method which aims in improving tracking of load signals on servo-hydraulic test rigs.

  14. CSNI validation matrix for PWR and BWR thermal-hydraulic system codes

    International Nuclear Information System (INIS)

    An internationally agreed validation matrix for PWR and BWR thermal-hydraulic system codes has been established by the CSNI-PWG-2 Task Group on Status and Assessment of Codes for Transients and ECCS. The matrix will be a guide for independent code assessment, will be a basis for the comparisons of code predictions performed with different system codes, and may contribute to the quantification of the uncertainty range of code predictions. (orig.)

  15. A flight simulator control system using electric torque motors

    Science.gov (United States)

    Musick, R. O.; Wagner, C. A.

    1975-01-01

    Control systems are required in flight simulators to provide representative stick and rudder pedal characteristics. A system has been developed that uses electric dc torque motors instead of the more common hydraulic actuators. The torque motor system overcomes certain disadvantages of hydraulic systems, such as high cost, high power consumption, noise, oil leaks, and safety problems. A description of the torque motor system is presented, including both electrical and mechanical design as well as performance characteristics. The system develops forces sufficiently high for most simulations, and is physically small and light enough to be used in most motion-base cockpits.

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

    Science.gov (United States)

    Susan-Resiga, Romeo

    2010-05-01

    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

  17. 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

  18. Thermal hydraulic issues of containment filtered venting system for a long operating time

    International Nuclear Information System (INIS)

    This study investigated the thermal hydraulic issues in the Containment Filtered Venting System (CFVS) for a long operating time using the MELCOR computer code. The modeling of the CFVS, including the models for pool scrubbing and the filter, was added to the input file for the OPR-1000, and a Station Blackout (SBO) was chosen as an accident scenario. Although depressurization in the containment building as a primary objective of the CFVS was successful, the decontamination feature by scrubbing and filtering in the CFVS for a long operating time could fail by the continuous evaporation of the scrubbing solution. After the operation of the CFVS, the atmosphere temperature in the CFVS became slightly above the water saturation temperature owing to the release of an amount of steam with high temperature from the containment building to the scrubbing solution. Reduced pipe diameters at the inlet and outlet of the CFVS vessel mitigated the evaporation of scrubbing water by controlling the amount of high-temperature steam and the water saturation temperature.

  19. Modelling of Hydraulic Robot

    DEFF Research Database (Denmark)

    Madsen, Henrik; Zhou, Jianjun; Hansen, Lars Henrik

    1997-01-01

    This paper describes a case study of identifying the physical model (or the grey box model) of a hydraulic test robot. The obtained model is intended to provide a basis for model-based control of the robot. The physical model is formulated in continuous time and is derived by application of the laws of physics on the system. The unknown (or uncertain) parameters are estimated with Maximum Likelihood (ML) parameter estimation. The identified model has been evaluated by comparing the measurements ...

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

    DEFF Research Database (Denmark)

    Janniche, Gry Sander; Christensen, Anders G.

    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.

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

    DEFF Research Database (Denmark)

    Aisopou, Angeliki; Stoianov, Ivan

    2013-01-01

    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.

  2. Coordinated joint motion control system with position error correction

    Science.gov (United States)

    Danko, George (Reno, NV)

    2011-11-22

    Disclosed are an articulated hydraulic machine supporting, control system and control method for same. The articulated hydraulic machine has an end effector for performing useful work. The control system is capable of controlling the end effector for automated movement along a preselected trajectory. The control system has a position error correction system to correct discrepancies between an actual end effector trajectory and a desired end effector trajectory. The correction system can employ one or more absolute position signals provided by one or more acceleration sensors supported by one or more movable machine elements. Good trajectory positioning and repeatability can be obtained. A two-joystick controller system is enabled, which can in some cases facilitate the operator's task and enhance their work quality and productivity.

  3. Control system design method

    Science.gov (United States)

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

    2012-02-21

    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.

  4. Software for control of information on the electric power system; Software para controle de informacoes sobre o sistema eletrico

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Marco Antonio da; Simoes, Manuel [Companhia Energetica de Sao Paulo (CESP), SP (Brazil)

    1998-07-01

    This paper describes the software System Situation, developed by CESP - Gerencia Regional de Operacao do Parana - Brazil, for optimization of the operation real time control. The software controls all the information from power plants, electric systems and transmission lines considering the following aspects: operational restriction of generator units; important anomalies; equipment operating, out of system equipment, hydraulic control and main facts occurred with equipment.

  5. GCFR plant control system

    International Nuclear Information System (INIS)

    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

  6. Development of computer code system THALES for thermal-hydraulic analysis of core meltdown accident, 1

    International Nuclear Information System (INIS)

    THALES is a computer code system for the thermal-hydraulic analysis of the core meltdown accident which is the risk-dominant accident of LWR's. Its first version was developed for the PWR analysis, which uses THALES-P for primary system thermal-hydraulics, THALES-M for core heatup and meltdown, and THALES-CV for containment temperature and pressure response. Several program libraries were also developed not only for THALES but for general usage. A new analysis technique of hydraulics in the primary cooling system was developed and used in THALES-P with aiming at accurate estimation of water level in water-steam mixture and shorter computer time, which are necessary for the core meltdown analysis. This report describes the outlines of the THALES code system, as well as the mathematical modeling and sample run results of the above-mentioned codes. Further are discussed the importance of the mixture levels and the necessity of the core slumping models. (author)

  7. 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)

  8. Study of Plant Oil and its Ageing Effect on Hydraulic System Efficiency and Rheological Performance

    Directory of Open Access Journals (Sweden)

    W.B. Wan Nik

    2007-01-01

    Full Text Available The effects of oil ageing on hydraulic system efficiency and oil rheological performance were studied. The various physical and chemical properties of fresh and aged oils were studied by determining total acid value, iodine value and density. The variation of oil functional group was analyzed by FTIR. The rheological behavior i.e., variation of viscosity with time, temperature and shear rate was studied using Brookfield viscometer. An attempt was made to establish the relationship between variation of viscosity and time of fresh and aged oil. The hydraulic performance has been investigated by determining system volumetric and mechanical efficiencies. The results show that the volumetric efficiency increases with ageing period while mechanical efficiency decreases when the oil ageing time increases.

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

    Czech Academy of Sciences Publication Activity Database

    Müller, M.; Prášil, L.; Zima, Patrik

    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

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

    International Nuclear Information System (INIS)

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

  11. Hydraulic balancing of heating systems according to VOB; Hydraulischer Abgleich von Heizungsanlagen gemaess VOB

    Energy Technology Data Exchange (ETDEWEB)

    Stich, D. [Oventrop (F.W.) Arn. Sohn KG, Olsberg (Germany)

    1999-11-01

    Hydraulic balancing of pipe systems including radiators is not only a physical necessity but is required also in VOB part C - DIN 18 380. Two major points arising from this are dealt with in the article. (orig.) [Deutsch] Der hydraulische Abgleich von Rohrnetzen einschliesslich der Heizkoerper ist nicht nur eine physikalische Notwendigkeit, sondern wird auch in der VOB Teil C - DIN 18 380 gefordert. Daraus gehen zwei wesentliche Punkte hervor, die im folgenden naeher eroertert werden. (orig.)

  12. Study of Plant Oil and its Ageing Effect on Hydraulic System Efficiency and Rheological Performance

    OpenAIRE

    W. B. Wan Nik; K.H. Ku Bulat; H.B. Senin; Ali, N A; M.D. Rahman; F.N. Ani

    2007-01-01

    The effects of oil ageing on hydraulic system efficiency and oil rheological performance were studied. The various physical and chemical properties of fresh and aged oils were studied by determining total acid value, iodine value and density. The variation of oil functional group was analyzed by FTIR. The rheological behavior i.e., variation of viscosity with time, temperature and shear rate was studied using Brookfield viscometer. An attempt was made to establish the relationship between var...

  13. Improving the Hydraulic Performance of Stormwater Infiltration Systems in Clay Tills

    DEFF Research Database (Denmark)

    Bockhorn, Britta

    2015-01-01

    Many cities of the Northern Hemisphere are covered by low permeable clay tills, which pose a challenge for stormwater infiltration practices. However, clay tills are amongst the most heterogeneous types of sediments and hydraulic conductivities can vary by several orders of magnitude. This PhD study was initiated with the objective to test and evaluate if the hydraulic performance of stormwater infiltration systems can be significantly improved if the site-specific geological heterogeneity is incorporated into the design and siting of such systems. The assessment is based on different field investigations on two typical Danish clay till sites, and one modeling study with the integrated surface water and groundwater model HydroGeoSphere. The saturated hydraulic conductivity (Ksat) is the most critical soil physical parameter when it comes to sizing stormwater infiltration systems. In the first study, different field methods for Ksat estimation, the double ring infiltrometer, the Guelph permeameter and falling head infiltration tests in a small excavation, were compared and evaluated for their capability to return realistic Ksat values in tills. The double ring infiltrometer and the Guelph permeameter represent suitable methods for sizing stormwater infiltration systems if measurements are combined with geological knowledge from maps of near-surface deposits and borehole descriptions. If space allows, the more invasive infiltration tests in a small excavation are recommended, because measurements are less influenced by the local hydraulic heterogeneity and therefore give the most realistic values. In a second study, non-invasive geoelectrical surveys were compared with data from invasive geological methods, including borehole descriptions, one description of a large excavation and near-surface spear auger mapping. The data returned a significant correlation of geoelectrical and spear auger mapped surface sediments. Furthermore, a highly permeable oxidized fracture-zone at greater depths was apparent on the 2D geoelectrical profiles. The successful identification of highly permeable zones in clay tills has potential for improving the hydraulic performance of stormwater infiltration systems. The third study was an assessment of the influence of small-scale soil physical features in clay tills on the hydraulic performance of stormwater infiltration systems based on a HydroGeoSphere model. The incorporation of soil characteristics below and above the CaCO3 boundary into simulated soil columns showed an increase in infiltration capacities by a factor of 22 compared to homogenous clay. Infiltration showed a further increase of 8% if vertical tectonic fractures were included and by another 61% if biopores like earthworm burrows were also added. A comparison of HydroGeoSphere infiltration hydrographs with a simple soakaway model (Roldin et al. 2012b) showed that the exclusion of small-scale soil physical features may result in significant underestimation of the hydraulic performance of stormwater infiltration systems. Models employing standard soil physical parameters should be used with care as they do not always realistically describe site-specific hydrologic properties. A fourth study showed that the hydraulic performance of infiltration trenches was increased by a factor of two, when spear auger mapping and geoelectrical surveying were used to position the trenches.

  14. Environmentally Friendly, Rheoreversible, Hydraulic-fracturing Fluids for Enhanced Geothermal Systems

    Energy Technology Data Exchange (ETDEWEB)

    Shao, Hongbo; Kabilan, Senthil; Stephens, Sean A.; Suresh, Niraj; Beck, Anthon NR; Varga, Tamas; Martin, Paul F.; Kuprat, Andrew P.; Jung, Hun Bok; Um, Wooyong; Bonneville, Alain; Heldebrant, David J.; Carroll, KC; Moore, Joseph; Fernandez, Carlos A.

    2015-07-01

    Cost-effective creation of high-permeability reservoirs inside deep crystalline bedrock is the primary challenge for the feasibility of enhanced geothermal systems (EGS). Current reservoir stimulation entails adverse environmental impacts and substantial economic costs due to the utilization of large volumes of water “doped” with chemicals including rheology modifiers, scale and corrosion inhibitors, biocides, friction reducers among others where, typically, little or no information of composition and toxicity is disclosed. An environmentally benign, CO2-activated, rheoreversible fracturing fluid has recently been developed that significantly enhances rock permeability at effective stress significantly lower than current technology. We evaluate the potential of this novel fracturing fluid for application on geothermal sites under different chemical and geomechanical conditions, by performing laboratory-scale fracturing experiments with different rock sources under different confining pressures, temperatures, and pH environments. The results demonstrate that CO2-reactive aqueous solutions of environmentally amenable Polyallylamine (PAA) represent a highly versatile fracturing fluid technology. This fracturing fluid creates/propagates fracture networks through highly impermeable crystalline rock at significantly lower effective stress as compared to control experiments where no PAA was present, and permeability enhancement was significantly increased for PAA compared to conventional hydraulic fracturing controls. This was evident in all experiments, including variable rock source/type, operation pressure and temperature (over the entire range for EGS applications), as well as over a wide range of formation-water pH values. This versatile novel fracturing fluid technology represents a great alternative to industrially available fracturing fluids for cost-effective and competitive geothermal energy production.

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

    International Nuclear Information System (INIS)

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

  16. A Novel Control Approach Based on Second Order Sliding Modes & Its Application to Hydraulic Drives

    DEFF Research Database (Denmark)

    Schmidt, Lasse; Andersen, Torben Ole; Pedersen, Henrik C.

    2013-01-01

    Sliding modes impose strong robustness toward parametric plant uncertainties and disturbances and 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. 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 ...

  17. Real time seismic traffic light systems for hydraulic stimulations in deep geothermal systems

    Science.gov (United States)

    Wegler, Ulrich; Vasterling, Margarete; Dinske, Carsten; Becker, Jan

    2015-04-01

    In order to mitigate the risk associated with induced seismicity caused by hydraulic stimulations in deep geothermal systems so called traffic light systems (risk management plans) are used. These systems consist of a local seismic monitoring and an estimate of the current seismic hazard based on observed induced seismicity. The current hazard is compared to threshold values. Measures to reduce the seismic hazard (e.g. reducing the flow rate) specified in the risk management plan are taken, if thresholds are exceeded. Standard traffic light systems use the largest recorded magnitude or peak ground velocity to estimate current seismic hazard caused by induced earthquakes. We developed a real time technique that computes the probability of exceedance for an undesired magnitude using a statistical analysis of recorded micro-seismicity. Based on the in real time generated earthquake catalogue, we compute the magnitude of completeness, the b-value of the Gutenberg-Richter law, and the so-called seismogenic index. These three quantities are updated in real time, if more induced earthquakes are detected. Using the flow rate of the hydraulic stimulation, which we assume to be recorded in real time as well, we calculate the expected seismicity for the next hours. In particular, we compute the probability of exceedance for a predefined critical magnitude. The value is permanently updated and compared to predefined threshold values of the traffic light system. Additionally to the scenario of a continued stimulation with the current flow rate, we also consider the case of an immediate shut-in. For this scenario the probability of exceedance is computed using a modified Omori law. The developed algorithm is implemented in the real-time earthquake monitoring software SeisComP3 including a graphical user interface. So far the traffic light algorithm has only been tested in playback mode simulating a real time scenario. For example, using data of the Basel Deep Heat Mining project and selecting a probability of exceedance of 60 percent for a critical magnitude of ML = 2.7, our traffic light algorithm turns from green to amber four hours before the first magnitude 2.7 earthquake in Basel, and it turns to red two hours before this event.

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

    Science.gov (United States)

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

    2013-01-01

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

  19. 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 the obtained results will be presented and discussed. (author)

  20. Thermal Hydraulic numerical analysis of Fusion superconducting magnet systems

    OpenAIRE

    Kholia, Akshat

    2013-01-01

    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 ...

  1. Experiences of Using MATLAB/Simulink in Simulation and Control of Fluid Power Systems

    DEFF Research Database (Denmark)

    Zhou, Jianjun; Conrad, Finn; Sřrensen, Torben

    1999-01-01

    MATLAB and Simulink are widely used as primary software tools in teaching and research around the word. This paper presents our experiences of using MATLAB/Simulink in simulation and control of fluid power systems. The application concerned mainly in this paper is a hydraulic test robot, shown in Figure 1, which was designed and implemented in our hydraulic laboratory.

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

    OpenAIRE

    Nenglian Feng; Hongwen He; Jiankun Peng

    2013-01-01

    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...

  3. 46 CFR 58.30-10 - Hydraulic fluid.

    Science.gov (United States)

    2010-10-01

    ... manufacturers and ANSI B93.5 (incorporated by reference; see 46 CFR 58.03-1) shall be considered in the... 46 Shipping 2 2010-10-01 2010-10-01 false Hydraulic fluid. 58.30-10 Section 58.30-10 Shipping... AND RELATED SYSTEMS Fluid Power and Control Systems § 58.30-10 Hydraulic fluid. (a) The...

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

    International Nuclear Information System (INIS)

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

  5. 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

  6. Irradiation facilities, hydraulic rabbit system, and sample handling for the TRIGA Heidelberg II

    International Nuclear Information System (INIS)

    Based on the eight years' experience with the research reactor TRIGA Heidelberg I, a new concept of the facilities for biomedical irradiation problems has been developed. These ideas have been incorporated in the TRIGA Heidelberg II in the final building of the Institute of Nuclear Medicine in the German Cancer Research Center at Heidelberg. The in-core irradiation stations and an open rotary system, each of which can be loaded and unloaded by a hydraulic transport system, are described in detail. The organization and the equipment for handling large numbers of samples under radiation protection are explained. The advantages of the system are discussed. (orig.)

  7. Thermal-Hydraulic System Codes in Nulcear Reactor Safety and Qualification Procedures

    OpenAIRE

    Alessandro Petruzzi; Francesco D'Auria

    2008-01-01

    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 pha...

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

    DEFF Research Database (Denmark)

    Stecki, J. S.; Conrad, Finn

    2002-01-01

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

  9. Estimated hydraulic properties for the surficial-and bedrock-aquifer system, Meddybemps, Maine

    Science.gov (United States)

    Lyford, Forest P.; Garabedian, Stephen P.; Hansen, Bruce P.

    1999-01-01

    Analytical and numerical-modeling methods were used to estimate hydraulic properties of the aquifer system underlying the Eastern Surplus Company Superfund Site in Meddybemps, Maine. Estimates of hydraulic properties are needed to evaluate pathways for contaminants in ground water and to support evaluation and selection of remediation measures for contaminated ground water at this site. The hydraulic conductivity of surficial materials, determined from specific-capacity tests, ranges from 17 to 78 feet per day for wells completed in coarse-grained glaciomarine sediments, and from about 0.1 to 1.Ofoot per day for wells completed in till. The transmissivity of fractured bedrock determined from specific-capacity tests and aquifer tests in wells completed in less than 200 feet of bedrock ranges from about 0.09 to 130 feet squared per day. Relatively high values of transmissivity at the south end of the study area appear to be associated with a high-angle fracture or fracture zone that hydraulically connects two wells completed in bedrock. Transmissivities at six low-yielding (less than 0.5 gallon per minute) wells, which appear to lie within a poorly transmissive block of the bedrock, are consistently in a range of about 0.09 to 0.5 foot squared per day. The estimates of hydraulic conductivity and transmissivity in the southern half of the study area are supported by results of steady-state calibration of a numerical model and simulation of a 24-hour pumping test at a well completed in bedrock. Hydraulic conductivity values for the surficial aquifer used in the model were 30 feet per day for coarse-grained glaciomarine sediments, 0.001 to 0.01 foot per day for fine-grained glaciomarine sediments, and 0.1 to 0.5 foot per day for till. As part of model calibration, a relatively transmissive zone in the surficial aquifer was extended beyond the hypothesized extent of coarse-grained sediments eastward to the Dennys River. Hydraulic conductivity values used for bedrock in the model ranged from 3x10-4 to 1.5 feet per day. The highest values were in the fracture zone that hydraulically connects two wells and apparently extends to the Dennys River. The transmissivity of bedrock used in the model ranged from 0.03 to 150 feet squared per day, with the majority of the bedrock transmissivities set at 0.3 foot squared per day. Numerical modeling results indicated that a very low ratio of vertical hydraulic conductivity to thickness (1x10-9 days-l) was required to simulate a persistent cone of depression near a residential well that lies in the previously identified poorly transmissive block of bedrock.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-09-01

    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.

  11. 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 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)

  12. The remote control system

    International Nuclear Information System (INIS)

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

  13. Fuzzy logic electric vehicle regenerative antiskid braking and traction control system

    Science.gov (United States)

    Cikanek, S.R.

    1994-10-25

    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. 123 figs.

  14. Fuzzy logic electric vehicle regenerative antiskid braking and traction control system

    Science.gov (United States)

    Cikanek, Susan R. (Wixom, MI)

    1994-01-01

    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.

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

    International Nuclear Information System (INIS)

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

  16. A Frequency Response Approach to Sliding Control Design for Hydraulic Drives

    DEFF Research Database (Denmark)

    Schmidt, Lasse; Johansen, Per; Andersen, Torben Ole

    2014-01-01

    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 frequenc...

  17. Navigability Potential of Washington Rivers and Streams Determined with Hydraulic Geometry and a Geographic Information System

    Science.gov (United States)

    Magirl, Christopher S.; Olsen, Theresa D.

    2009-01-01

    Using discharge and channel geometry measurements from U.S. Geological Survey streamflow-gaging stations and data from a geographic information system, regression relations were derived to predict river depth, top width, and bottom width as a function of mean annual discharge for rivers in the State of Washington. A new technique also was proposed to determine bottom width in channels, a parameter that has received relatively little attention in the geomorphology literature. These regression equations, when combined with estimates of mean annual discharge available in the National Hydrography Dataset, enabled the prediction of hydraulic geometry for any stream or river in the State of Washington. Predictions of hydraulic geometry can then be compared to thresholds established by the Washington State Department of Natural Resources to determine navigability potential of rivers. Rivers with a mean annual discharge of 1,660 cubic feet per second or greater are 'probably navigable' and rivers with a mean annual discharge of 360 cubic feet per second or less are 'probably not navigable'. Variance in the dataset, however, leads to a relatively wide range of prediction intervals. For example, although the predicted hydraulic depth at a mean annual discharge of 1,660 cubic feet per second is 3.5 feet, 90-percent prediction intervals indicate that the actual hydraulic depth may range from 1.8 to 7.0 feet. This methodology does not determine navigability - a legal concept determined by federal common law - instead, this methodology is a tool for predicting channel depth, top width, and bottom width for rivers and streams in Washington.

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

    Science.gov (United States)

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

    2014-05-01

    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.

  19. Development and validation of three dimensional neutronics and thermal-hydraulics coupled system RECON

    International Nuclear Information System (INIS)

    On the basis of RELAP5, COBRA-? and NLSANMT codes, the three dimensional neutronics and thermal-hydraulics coupled system RECON was developed by means of the parallel processing model and parallel virtual machine technology. The ways of coupling were flexible since different combinations of codes can be selected for various coupled analyses; Validations of the coupled system were completed with a series of benchmarks. Specially in the MSLB benchmark, the comparison of results with other coupled codes demonstrates that RECON has good accuracy and is suitable for the analysis of reactivity insertion accident. (authors)

  20. The Control System Modeling and The Mechanical Structure Analysis For EMCVT

    Directory of Open Access Journals (Sweden)

    Lei ZHANG

    2013-07-01

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

  1. Variation of phytoplankton functional groups modulated by hydraulic controls in Hongze Lake, China.

    Science.gov (United States)

    Tian, Chang; Pei, Haiyan; Hu, Wenrong; Hao, Daping; Doblin, Martina A; Ren, Ying; Wei, Jielin; Feng, Yawei

    2015-11-01

    Hongze Lake is a large, shallow, polymictic, eutrophic lake in the eastern China. Phytoplankton functional groups in this lake were investigated from March 2011 to February 2013, and a comparison was made between the eastern, western, and northern regions. The lake shows strong fluctuations in water level caused by monsoon rains and regular hydraulic controls. By application of the phytoplankton functional group approach, this study aims to investigate the spatial and temporal dynamics and analyze their influencing factors. Altogether, 18 functional groups of phytoplankton were identified, encompassing 187 species. In order to seek the best variable describing the phytoplankton functional group distribution, 14 of the groups were analyzed in detail using redundancy analysis. Due to the turbid condition of the lake, the dominant functional groups were those tolerant of low light. The predominant functional groups in the annual succession were D (Cyclotella spp. and Synedra acus), T (Planctonema lauterbornii), P (Fragilaria crotonensis), X1 (Chlorella vulgaris and Chlorella pyrenoidosa), C (Cyclotella meneghiniana and Cyclotella ocellata), and Y (Cryptomonas erosa). An opposite relationship between water level and the biomass of predominant groups was observed in the present study. Water level fluctuations, caused by monsoonal climate and artificial drawdown, were significant factors influencing phytoplankton succession in Hongze Lake, since they alter the hydrological conditions and influence light and nutrient availability. The clearly demonstrated factors, which significantly influence phytoplankton dynamics in Hongze Lake, will help government manage the large shallow lakes with frequent water level fluctuations. PMID:26178825

  2. Quarter Car Active Suspension System Control Using PID Controller tuned by PSO

    Directory of Open Access Journals (Sweden)

    Wissam H. Al-Mutar

    2015-07-01

    Full Text Available The objective of this paper is to design an efficient control scheme for car suspension system. The purpose of suspension system in vehicles is to get more comfortable riding and good handling with road vibrations. A nonlinear hydraulic actuator is connected to passive suspension system in parallel with damper. The Particles Swarm Optimization is used to tune a PID controller for active suspension system. The designed controller is applied for quarter car suspension system and result is compared with passive suspension system model and input road profile. Simulation results show good performance for the designed controller

  3. Development of Arduino based wireless control system

    Science.gov (United States)

    Sun, Zhuoxiong; Dyke, Shirley J.; Pena, Francisco; Wilbee, Alana

    2015-03-01

    Over the past few decades, considerable attention has been given to structural control systems to mitigate structural vibration under natural hazards such as earthquakes and extreme weather conditions. Traditional wired structural control systems often employ a large amount of cables for communication among sensors, controllers and actuators. In such systems, implementation of wired sensors is usually quite complicated and expensive, especially on large scale structures such as bridges and buildings. To reduce the laborious installation and maintenance cost, wireless control systems (WCSs) are considered as a novel approach for structural vibration control. In this work, a WCS is developed based on the open source Arduino platform. Low cost, low power wireless sensing and communication components are built on the Arduino platform. Structural control algorithms are embedded within the wireless sensor board for feedback control. The developed WCS is first validated through a series of tests. Next, numerical simulations are performed simulating wireless control of a 3-story shear structure equipped with a semi-active control device (MR damper). Finally, experimental studies are carried out implementing the WCS on the 3-story shear structure in the Intelligent Infrastructure Systems Lab (IISL). A hydraulic shake table is used to generate seismic ground motions. The control performance is evaluated with the impact of modeling uncertainties, measurement noises as well as time delay and data loss induced by the wireless network. The developed WCS is shown to be effective in controlling structural vibrations under several historical earthquake ground motions.

  4. Numerical hydraulic modeling of urban waste water collecting systems : Working Project at Chazelles-sur-Lyon, France

    OpenAIRE

    Genty, Stanislas

    2014-01-01

    Urban waste water collecting systems are designed to convey domestic, industrial and storm water. When sizing sewer network, heavy rainfall must be considered to provide the needed hydraulic capacity for collection. Maintenance is also required in order to avoid anomalies such as inflow, infiltration and unusual polluted discharges from Combined Sewer Overflows (CSOs). Inflow and infiltration decrease the treatment yield at the Waste water Treatment Plant (WWTP) and participate in hydraulic o...

  5. Influence analysis of coupled neutronics and thermal-hydraulics on characteristics of supercritical water-cooled reactor system

    International Nuclear Information System (INIS)

    Coupled neutronics and thermal-hydraulics is one of the key issues of super critical water-cooled reactor system analysis. Taking the Super LWR concept proposed by Japan as example, the neutron cross-section library for supercritical water-cooled reactor was made by Dragon code, and then a two-group neutron diffusion calculation module was created. By combining with the thermal-hydraulic calculation module, the coupled neutronic and thermal-hydraulic calculation module of supercritical water-cooled reactor was finally obtained. By comparing the thermal-hydraulic behavior under the uncoupling calculation condition with that under the coupling calculation condition for both steady-state and transient analyses, thermal-hydraulic characteristics of supercritical water-cooled reactor under coupled neutronic and thermal-hydraulic condition was analyzed. The results show that, in steady-state case, the neutronic and thermal- hydraulic coupling will lead to the axial core power peak factor shifting along axial direction for both the inner and outer assemblies. It makes part of the cladding temperature rising but the maximum cladding temperature decreasing. In transient case, the neutronic and thermal-hydraulic coupling may cause the position changed of maximum cladding temperature. When the loss of feed-water heating occurs, the cladding temperature in the outer fuel assembly will become even higher than that in the inner fuel assembly at a certain time. Thus, the neutronic and thermal-hydraulic coupling has a significant impact on both the value and the location of the maximum cladding temperature. The calculation analysis can provide a theoretical reference for transient and safety analyses of supercritical water-cooled reactor. (authors)

  6. Thermal-hydraulic tests for primary coolant circuit structures of top entry system for LMFBR

    International Nuclear Information System (INIS)

    The Top Entry System for the LMFBR is a system which constitutes the primary reactor cooling loops by installing inverted U-piges among the reactor vessel (RV), intermediate heat exchangers (IHX) and the primary pumps. The adoption of this system has allowed to considerably reduce the overall lenngth of pipings compared with the conventional loop type FBR and furthermore, has the advantage of drastically minimizing the area of the container vessel. However, as it is new concept to provide a siphon type piping at the upper part of each component, various R and D works are being carried out relating to the Top Entry System in order to support the designing of the 1000 MWe LMFBR plant. As one of the R and Ds carried out, thermal-hydraulic tests were conducted. A water loop test on the model system to examine local thermal head relating to natural circulation and thermal transient of each part, and a sodium loop test to examine generative conditions of thermal stratification at the inverted U-pipe were conducted. As it is necessary to use an analysis code in order to predict thermal-hydraulics inside the inverted U-pipe, and examination by a two dimensional FEM code was performed using the above test data. (orig.)

  7. Intelligent flight control systems

    Science.gov (United States)

    Stengel, Robert F.

    1993-01-01

    The capabilities of flight control systems can be enhanced by designing them to emulate functions of natural intelligence. Intelligent control functions fall in three categories. Declarative actions involve decision-making, providing models for system monitoring, goal planning, and system/scenario identification. Procedural actions concern skilled behavior and have parallels in guidance, navigation, and adaptation. Reflexive actions are spontaneous, inner-loop responses for control and estimation. Intelligent flight control systems learn knowledge of the aircraft and its mission and adapt to changes in the flight environment. Cognitive models form an efficient basis for integrating 'outer-loop/inner-loop' control functions and for developing robust parallel-processing algorithms.

  8. Creation of an Enhanced Geothermal System through Hydraulic and Thermal Stimulation

    Energy Technology Data Exchange (ETDEWEB)

    Rose, Peter Eugene [Energy and Geoscience Institute at the University of Utah

    2013-04-15

    This report describes a 10-year DOE-funded project to design, characterize and create an Engineered Geothermal System (EGS) through a combination of hydraulic, thermal and chemical stimulation techniques. Volume 1 describes a four-year Phase 1 campaign, which focused on the east compartment of the Coso geothermal field. It includes a description of the geomechanical, geophysical, hydraulic, and geochemical studies that were conducted to characterize the reservoir in anticipation of the hydraulic stimulation experiment. Phase 1 ended prematurely when the drill bit intersected a very permeable fault zone during the redrilling of target stimulation well 34-9RD2. A hydraulic stimulation was inadvertently achieved, however, since the flow of drill mud from the well into the formation created an earthquake swarm near the wellbore that was recorded, located, analyzed and interpreted by project seismologists. Upon completion of Phase 1, the project shifted focus to a new target well, which was located within the southwest compartment of the Coso geothermal field. Volume 2 describes the Phase 2 studies on the geomechanical, geophysical, hydraulic, and geochemical aspects of the reservoir in and around target-stimulation well 46A-19RD, which is the deepest and hottest well ever drilled at Coso. Its total measured depth exceeding 12,000 ft. It spite of its great depth, this well is largely impermeable below a depth of about 9,000 ft, thus providing an excellent target for stimulation. In order to prepare 46A-19RD for stimulation, however, it was necessary to pull the slotted liner. This proved to be unachievable under the budget allocated by the Coso Operating Company partners, and this aspect of the project was abandoned, ending the program at Coso. The program then shifted to the EGS project at Desert Peak, which had a goal similar to the one at Coso of creating an EGS on the periphery of an existing geothermal reservoir. Volume 3 describes the activities that the Coso team contributed to the Desert Peak project, focusing largely on a geomechanical investigation of the Desert Peak reservoir, tracer testing between injectors 21-2 and 22-22 and the field�������¢����������������s main producers, and the chemical stimulation of target well 27-15.

  9. Creation of an Enhanced Geothermal System through Hydraulic and Thermal Stimulation

    Energy Technology Data Exchange (ETDEWEB)

    Rose, Peter Eugene [Energy and Geoscience Institute at the Univerity of Utah

    2013-04-15

    This report describes a 10-year DOE-funded project to design, characterize and create an Engineered Geothermal System (EGS) through a combination of hydraulic, thermal and chemical stimulation techniques. Volume 1 describes a four-year Phase 1 campaign, which focused on the east compartment of the Coso geothermal field. It includes a description of the geomechanical, geophysical, hydraulic, and geochemical studies that were conducted to characterize the reservoir in anticipation of the hydraulic stimulation experiment. Phase 1 ended prematurely when the drill bit intersected a very permeable fault zone during the redrilling of target stimulation well 34-9RD2. A hydraulic stimulation was inadvertently achieved, however, since the flow of drill mud from the well into the formation created an earthquake swarm near the wellbore that was recorded, located, analyzed and interpreted by project seismologists. Upon completion of Phase 1, the project shifted focus to a new target well, which was located within the southwest compartment of the Coso geothermal field. Volume 2 describes the Phase 2 studies on the geomechanical, geophysical, hydraulic, and geochemical aspects of the reservoir in and around target-stimulation well 46A-19RD, which is the deepest and hottest well ever drilled at Coso. Its total measured depth exceeding 12,000 ft. It spite of its great depth, this well is largely impermeable below a depth of about 9,000 ft, thus providing an excellent target for stimulation. In order to prepare 46A-19RD for stimulation, however, it was necessary to pull the slotted liner. This proved to be unachievable under the budget allocated by the Coso Operating Company partners, and this aspect of the project was abandoned, ending the program at Coso. The program then shifted to the EGS project at Desert Peak, which had a goal similar to the one at Coso of creating an EGS on the periphery of an existing geothermal reservoir. Volume 3 describes the activities that the Coso team contributed to the Desert Peak project, focusing largely on a geomechanical investigation of the Desert Peak reservoir, tracer testing between injectors 21-2 and 22-22 and the field�s main producers, and the chemical stimulation of target well 27-15.

  10. Homeostasis in leaf water potentials on leeward and windward sides of desert shrub crowns: water loss control vs. high hydraulic efficiency.

    Science.gov (United States)

    Iogna, Patricia A; Bucci, Sandra J; Scholz, Fabián G; Goldstein, Guillermo

    2013-11-01

    Phenotypic plasticity in morphophysiological leaf traits in response to wind was studied in two dominant shrub species of the Patagonian steppe, used as model systems for understanding effects of high wind speed on leaf water relations and hydraulic properties of small woody plants. Morpho-anatomical traits, hydraulic conductance and conductivity and water relations in leaves of wind-exposed and protected crown sides were examined during the summer with nearly continuous high winds. Although exposed sides of the crowns were subjected to higher wind speeds and air saturation deficits than the protected sides, leaves throughout the crown had similar minimum leaf water potential (?L). The two species were able to maintain homeostasis in minimum ?L using different physiological mechanisms. Berberis microphylla avoided a decrease in the minimum ?L in the exposed side of the crown by reducing water loss by stomatal control, loss of cell turgor and low epidermal conductance. Colliguaja integerrima increased leaf water transport efficiency to maintain transpiration rates without increasing the driving force for water loss in the wind-exposed crown side. Leaf physiological changes within the crown help to prevent the decrease of minimum ?L and thus contribute to the maintenance of homeostasis, assuring the hydraulic integrity of the plant under unfavorable conditions. The responses of leaf traits that contribute to mechanical resistance (leaf mass per area and thickness) differed from those of large physiological traits by exhibiting low phenotypic plasticity. The results of this study help us to understand the unique properties of shrubs which have different hydraulic architecture compared to trees. PMID:23624673

  11. Environmental restoration: Integrating hydraulic control of groundwater, innovative contaminant removal technologies and wetlands restoration--A case study at SRS

    International Nuclear Information System (INIS)

    The groundwater remediation program at the F and H Seepage Basins, Savannah River Sits (SRS) is a case study of the integration of various environmental restoration technologies at a single waste site. Hydraulic control measures are being designed to mitigate the discharge of groundwater plumes to surface water. One of the primary constituents of the plumes is tritium. An extraction and reinjection scenario is being designed to keep the tritium in circulation in the shallow groundwater, until it can naturally decay. This will be accomplished by extracting groundwater downgradient of the waste sites, treatment, and reinjection of the tritiated water into the water table upgradient of the basins. Innovative in-situ technologies, including electrolytic migration, are being field tested at the site to augment the pump-treat-reinject system. The in-situ technologies target removal of contaminants which are relatively immobile, yet represent long term risks to human health and the environment. Wetland restoration is an integral part of the F and H remediation program. Both in-situ treatment of the groundwater discharging the wetlands to adjust the pH, and replacement of water loss due to the groundwater extraction program ar being considered. Toxicity studies indicate that drought and the effects of low pH groundwater discharge have been factors in observed tree mortality in wetlands near the waste sites

  12. ALFA Detector Control System

    CERN Document Server

    Oleiro Seabra, Luis Filipe; The ATLAS collaboration

    2015-01-01

    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.

  13. ALFA Detector Control System

    CERN Document Server

    Oleiro Seabra, Luis Filipe; The ATLAS collaboration

    2015-01-01

    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.

  14. Coupled thermal-hydraulic and fission product transport analysis of reactor coolant systems during degraded core accidents

    International Nuclear Information System (INIS)

    This paper describes a methodology with which thermal-hydraulic and fission product transport and deposition calculations can be simultaneously carried out to more properly predict fission product behavior within reactor coolant systems (RCS) during postulated degraded core accidents. The methodology involves the coupling of the EPRI-sponsored codes CORMLT, which models the in-vessel melt-down progression, PSAAC, which models the thermal-hydraulic behavior within the RCS, and RAFT, which performs the aerosol transport and deposition computations. Simulations of the accident sequences TMLB' (PWR) and TW (BWR) are carried out with the coupled code. The preliminary results indicate that fission product decay heating substantially alters the thermal-hydraulic conditions within the RCS; however, the resulting alteration of RCS thermal-hydraulics does not appear to materially affect aerosol behavior

  15. Modeling and Simulation of Hybrid Solar Photovoltaic, Wind turbine and Hydraulic Power System

    Directory of Open Access Journals (Sweden)

    S. Sami

    2015-09-01

    Full Text Available This paper presents the modeling and simulation of the energy conversion equations describing the total power generated by a hybrid system of solar photovoltaic, wind turbine and hydraulic turbine. To validate this simulation model, the aforementioned equations were coded with MATLAB V13.2, compared to experimental data. The model is intended to be used as an optimization and design tool. A block diagram approach was used during the simulation with MATLAB. The model predicted results compared fairly with experimental data under various conditions.

  16. Formation and hydraulic effects of deposits in high temperature sodium coolant systems

    International Nuclear Information System (INIS)

    Deposition of sodium impurities in the high temperature (6000C), high flow (Reynolds Number approximately equal to 8 x 104) regions of a sodium coolant circuit is being studied to determine its possible hydraulic effects. Increases in flow impedance (pressure drop/volume flow2) of up to 30 percent have been detected in an annular flow sensor. The apparatus and preliminary results of these tests are presented. Continuing tests are to specifically identify the materials involved and the system conditions under which the formations occur

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

    OpenAIRE

    Enrique Vidal; Rico H. Hansen; Morten M. Kramer

    2013-01-01

    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, ...

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

    DEFF Research Database (Denmark)

    Hansen, Rico Hjerm; Kramer, Morten; Vidal, Enrique

    2013-01-01

    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, sup...

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

    OpenAIRE

    Shao, Yiqiong

    2011-01-01

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

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

    International Nuclear Information System (INIS)

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

  1. Hardware-in-the-loop of Simulation for a Hydraulic Antilock Brake System

    Directory of Open Access Journals (Sweden)

    Ayman A. Aly

    2013-01-01

    Full Text Available Hardware-In-the-Loop (HIL of simulation policy is used as a rapid and economical tool for developing automotive systems effectively and for dangerous situations tests such as extreme road conditions or high travelling speeds. A method for building a HIL of simulation a hydraulic Antilock Braking System (ABS based on MATLAB/Simulink is presented in this paper. The system is implemented for research purposes as well as for the application in educational process. It can help the user heightening the efficiency when developing the electronic device. Also, the system can be used as teaching demo software. Experiment tests of HIL scheme were carried to ensure the feasibility and effectiveness of the system.

  2. Auxiliary building thermal-hydraulic conditions relevant to radionuclide retention for the interfacing-systems LOCA

    International Nuclear Information System (INIS)

    Following a postulated core melt accident in a light-water nuclear power reactor, thermodynamic conditions in regions containing radioactive materials released from the core could markedly influence retention of those materials. Usually the regions in question are the containment building and suppression systems. However, in postulated accidents in which the primary reactor system fluid bursts into an interfacing system, such as the low pressure injection system, the effluent could bypass containment and be released in the auxiliary safeguards, or other support buildings. In this paper, the thermal-hydraulic characteristics in the auxiliary building, and their significance on aerosol retention, are reported for an interfacing-systems LOCA. The work is sponsored by the Electric Power Research Institute

  3. A modular control system

    International Nuclear Information System (INIS)

    The main objective of the modular control system is to provide the requirements to most of the processes supervision and control applications within the industrial automatization area. The design is based on distribution, modulation and expansion concepts. (Author)

  4. Motion control systems

    CERN Document Server

    Sabanovic, Asif

    2011-01-01

    "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...

  5. Modeling digital control systems in TRACE

    International Nuclear Information System (INIS)

    The US Nuclear Regulatory Commission (NRC) has developed a number of thermal hydraulic safety analysis codes that are used to predict nuclear reactor and plant systems behavior under normal, accident, and severe accident conditions for current and advanced reactors. These codes supports NRC's assessment of continued safety of operating reactors, as well as anticipation of new safety issues and accident phenomena in nuclear plants, including advanced reactors. The current thermal hydraulic safety code of choice for the NRC is the TRAC RELAP Enhanced Computational Engine (TRACE). This safety analysis code has evolved to contain function block programming suitable for modeling analog control components. Until now, there has been no analytical model to study the response of digital control and safety systems for safety analysis in TRACE. New plant construction will be completely digital in the protection and control systems and existing plants are undergoing upgrades to replace analog components with digital systems. For upgrades to existing plants, NRC will review licensee analysis of any updates to current chapter 15 accident analyses, needed to support license amendment requests. For accident analysis of new plants and upgrades to existing plants that include digital components these analysis need to include the effects of digital components on the progress of the accidents in the analyses. This paper will present an approach to incorporate the digital components in the analysis. (authors)

  6. Applied Control Systems Design

    CERN Document Server

    Mahmoud, Magdi S

    2012-01-01

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

  7. Parametric thermal-hydraulic studies of HTGR reactor vessel system. Consequences on the structure lifetime

    International Nuclear Information System (INIS)

    In the framework of Gas Cooled Reactor design assessment, an important point to calculate is the temperature fields on the main structures in nominal and accidental situations in order to determine the consequences on the reactor lifetime. This document presents such thermal-hydraulic and thermal-mechanical studies for the HTGR (High Temperature Gas-cooled Reactor) vessel system in normal operation and pressurized LOFC (Loss Of Forced Coolant) accidents. Thermal- hydraulic calculations address the key issues for pressurized LOFC transients and evaluate the contribution of main design and modeling parameters. These calculations are performed using the CFD (Computational Fluid Dynamics) code STAR-CD. For these transients where the primary system remains pressurized, it is necessary to carry out mechanical analyses on the structures to assess the damage levels reached. Sensitivity studies are conducted taking into account different irradiation levels and types of graphite, different assumptions of mass exchanging rate between the stagnant helium beside the vessel and the coolant in the annular channel between core barrel and vessel, and different assumptions regarding the natural convection of helium. To determine the structure temperatures, the thermal-hydraulic studies show that the conductivity value of graphite reflectors is the main factor for both the normal operation and the accidental situation considered (pressurized LOFC). The thermal-mechanical analyses allow evaluating the consequences of these loading situations for the lifetime assessment of the main metallic structures, namely the core barrel and the pressure vessel. The results obtained show that, for both structures, the damage levels remain below design limitations. (authors)

  8. Thermal-hydraulic simulation and analysis of Research Reactor Cooling Systems

    International Nuclear Information System (INIS)

    The objective of the present study is to formulate a model to simulate the thermal hydraulic behavior of integrated cooling system in a typical material testing reactor (MTR) under loss of ultimate heat sink, the model involves three interactively coupled sub-models for reactor core, heat exchanger and cooling tower. The developed model predicts the temperature profiles in addition it predicts inlet and outlet temperatures of the hot and cold stream as well as the heat exchangers and cooling tower. The model is validated against PARET code for steady-state operation and also verified by the reactor operational records, and then the model is used to simulate the thermal-hydraulic behavior of the reactor under a loss of ultimate heat sink. The simulation is performed for two operational regimes named regime I of (11 MW) thermal power and three operated cooling tower cells and regime II of (22 MW) thermal power and six operated cooling tower cells. In regime I, the simulation is performed for 1, 2 and 3 cooling tower failed cells while in regime II, it is performed for 1, 2, 3, 4, 5 and 6 cooling tower failed cells. The safety action is conducted by the reactor protection system (RPS) named power reduction safety action, it is triggered to decrease the reactor power by amount of 20% of the present power when the water inlet temperature to the core reaches 43 degree C and a scram (emergency shutdown) is triggered in case of the inlet temperature reaches 44 degree C. The model results are analyzed and discussed. The temperature profiles of fuel, clad and coolant are predicted during transient where its maximum values are far from thermal hydraulic limits.

  9. Control and optimization system

    Science.gov (United States)

    Xinsheng, Lou

    2013-02-12

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

  10. Hydraulic tests with measuring and control plug for KNK II temperature transient experiments (TETRA)

    International Nuclear Information System (INIS)

    For the temperature transient experiments (TETRA) at KNK II the sodium flow rate of a 19-pin test bundle integrated in an annular fuel element shall be reduced and the coolant temperature consequently increased with the help of a measuring and control plug. A valve will act as orificing device. It is designed in such a way that even in closed condition a remaining mass flow will be given, with which the aimed maximum coolant temperature of 750 deg. C will be reached at the outlet of the test bundle. With the nominal mass flow of the test bundle of 1.35 kg/s and a core pressure drop of 1.33 bar, for the test operation with maximum coolant outlet temperature a minimum mass flow of 0.76 kg/s and a test element pressure drop of 0.4 bar is calculated. The experimental plug has therefore to provide a pressure drop of 0.9 bar. During the hydraulic tests the pressure drop of the plug and the characteristic of the valve had to be determined. For this purpose a test line with the same inner dimensions and installations as the plug was established and a first series of experiments was performed in a water circuit. The experiments showed that most of the pressure drop was caused by the valve. It amounts to 0.5 bar with the minimum mass flow, i.e. the aimed pressure drop of 0.9 bar is not yet reached. Further tests will be performed with smaller ring gaps of the valve. In a second series of experiments the characteristics of four valves with different geometries have been determined

  11. Experimental-based Modelling and Simulation of Water Hydraulic Mechatronics Test Facilities for Motion Control and Operation in Environmental Sensitive Applications` Areas

    DEFF Research Database (Denmark)

    Conrad, Finn; Pobedza, J.; Sobczyk, A.

    2003-01-01

    The paper presents experimental-based modelling, simulation, analysis and design of water hydraulic actuators for motion control of machines, lifts, cranes and robots. The contributions includes results from on-going research projects on fluid power and mechatronics based on tap water hydraulic proportional valves and servo actuators for motion control and power transmission undertaken in co-operation by Technical University, DTU and Cracow University of Technology, CUT. The results of this rese...

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

    Science.gov (United States)

    Human Engineering Inst., Cleveland, OH.

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

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

    Science.gov (United States)

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

    2012-05-01

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

  14. Control rod shutdown system

    International Nuclear Information System (INIS)

    The present invention provides a control rod terminating system in a BWR type nuclear power plant, which stops an induction electric motor as rapidly as possible to terminate the control rods. Namely, the control rod stopping system controls reactor power by inserting/withdrawing control rods into a reactor by driving them by the induction electric motor. The system is provided with a control device for controlling the control rods and a control device for controlling the braking device. The control device outputs a braking operation signal for actuating the braking device during operation of the control rods to stop the operation of the control rods. Further, the braking device has at least two kinds of breaks, namely, a first and a second brakes. The two kinds of brakes are actuated by receiving the brake operation signals at different timings. The brake device is used also for keeping the control rods after the stopping. Even if a stopping torque of each of the breaks is small, different two kinds of brakes are operated at different timings thereby capable of obtaining a large stopping torque as a total. (I.S.)

  15. 49 CFR 571.105 - Standard No. 105; Hydraulic and electric brake systems.

    Science.gov (United States)

    2010-10-01

    ...transmission of the service brake control signal, failure of a brake control circuit. (g) For an EV with...application of the service brake control. Restore the system to...in speed, then throttle closed quickly to attain...

  16. Thermal-hydraulic evaluation of passive containment cooling system of improved APR+ during LOCAs

    International Nuclear Information System (INIS)

    In performance of Passive Containment Cooling System (PCCS), sound operation of PCCS heat exchanger (HX) tubes is vital. To clarify their heat transfer function, various experiments are in progress, involving our group. Furthermore, in case of externally condensed HXs, careful evaluation of flow instability inside HX tubes are of prime importance. In PANDA integral tests targeting HXs of KERENA, a huge oscillation of flow inside tubes is observed. Flow instability is attributed to various reasons and classified into two types: static instability (ex. Ledinegg instability) and dynamic instability (ex. density wave oscillation). The former one is related to multiple stable flow rates at a given pressure drop under equilibrium condition while the latter one involves propagation time and feedback phenomena in transient condition. PCCS tubes correspond to the second type, dynamic instability. The detailed explanations are well documented. Our group suggested a PCCS design featuring an air holdup tank (AHT) for removing air near heat exchangers. Based on the design, the thermal hydraulic characteristics of PCCS are explored in this paper. Thermal hydraulic assessment of proposed PCCS is performed using a system code, MARS. Based on APR+, the required number of PCCS HX tubes are calculated with respect to AHT volume. We confirmed that larger AHT is preferred. Flow instability inside PCCS HX tubes are observed. Through sensitivity study, larger inlet orifice plate, return nozzle height, and tube angle are found to be most effective in stabilizing the flow

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  19. Thermal-hydraulic evaluation of passive containment cooling system of improved APR+ during LOCAs

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Byong Guk; No, Hee Cheon [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2014-05-15

    In performance of Passive Containment Cooling System (PCCS), sound operation of PCCS heat exchanger (HX) tubes is vital. To clarify their heat transfer function, various experiments are in progress, involving our group. Furthermore, in case of externally condensed HXs, careful evaluation of flow instability inside HX tubes are of prime importance. In PANDA integral tests targeting HXs of KERENA, a huge oscillation of flow inside tubes is observed. Flow instability is attributed to various reasons and classified into two types: static instability (ex. Ledinegg instability) and dynamic instability (ex. density wave oscillation). The former one is related to multiple stable flow rates at a given pressure drop under equilibrium condition while the latter one involves propagation time and feedback phenomena in transient condition. PCCS tubes correspond to the second type, dynamic instability. The detailed explanations are well documented. Our group suggested a PCCS design featuring an air holdup tank (AHT) for removing air near heat exchangers. Based on the design, the thermal hydraulic characteristics of PCCS are explored in this paper. Thermal hydraulic assessment of proposed PCCS is performed using a system code, MARS. Based on APR+, the required number of PCCS HX tubes are calculated with respect to AHT volume. We confirmed that larger AHT is preferred. Flow instability inside PCCS HX tubes are observed. Through sensitivity study, larger inlet orifice plate, return nozzle height, and tube angle are found to be most effective in stabilizing the flow.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-10-15

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

  1. Discrete control systems

    CERN Document Server

    Okuyama, Yoshifumi

    2014-01-01

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

  2. A model selection support system for numerical simulations of nuclear thermal-hydraulics

    International Nuclear Information System (INIS)

    In order to execute efficiently a dynamic simulation of a large-scaled engineering system such as a nuclear power plant, it is necessary to develop intelligent simulation support system for all phases of the simulation. This study is concerned with the intelligent support for the program development phase and is engaged in the adequate model selection support method by applying AI (Artificial Intelligence) techniques to execute a simulation consistent with its purpose and conditions. A proto-type expert system to support the model selection for numerical simulations of nuclear thermal-hydraulics in the case of cold leg small break loss-of-coolant accident of PWR plant is now under development on a personal computer. The steps to support the selection of both fluid model and constitutive equations for the drift flux model have been developed. Several cases of model selection were carried out and reasonable model selection results were obtained. (author)

  3. The 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. (Auth.)

  4. Control system design guide

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-05-01

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

  5. Spacecraft momentum control systems

    CERN Document Server

    Leve, Frederick A; Peck, Mason A

    2015-01-01

    The goal of this book is to serve both as a practical technical reference and a resource for gaining a fuller understanding of the state of the art of spacecraft momentum control systems, specifically looking at control moment gyroscopes (CMGs). As a result, the subject matter includes theory, technology, and systems engineering. The authors combine material on system-level architecture of spacecraft that feature momentum-control systems with material about the momentum-control hardware and software. This also encompasses material on the theoretical and algorithmic approaches to the control of space vehicles with CMGs. In essence, CMGs are the attitude-control actuators that make contemporary highly agile spacecraft possible. The rise of commercial Earth imaging, the advances in privately built spacecraft (including small satellites), and the growing popularity of the subject matter in academic circles over the past decade argues that now is the time for an in-depth treatment of the topic. CMGs are augmented ...

  6. Fault Tolerant Control Systems

    DEFF Research Database (Denmark)

    Břgh, S.A.

    1997-01-01

    This thesis considered the development of fault tolerant control systems. The focus was on the category of automated processes that do not necessarily comprise a high number of identical sensors and actuators to maintain safe operation, but still have a potential for improving immunity to component failures. It is often feasible to increase availability for these control loops by designing the control system to perform on-line detection and reconfiguration in case of faults before the safety sys...

  7. Hydraulic Shuttle Irradiation System (HSIS) Recently Installed in the Advanced Test Reactor (ATR)

    Energy Technology Data Exchange (ETDEWEB)

    A. Joseph Palmer; Gerry L. McCormick; Shannon J. Corrigan

    2010-06-01

    2010 International Congress on Advances in Nuclear Power Plants (ICAPP’10) ANS Annual Meeting Imbedded Topical San Diego, CA June 13 – 17, 2010 Hydraulic Shuttle Irradiation System (HSIS) Recently Installed in the Advanced Test Reactor (ATR) Author: A. Joseph Palmer, Mechanical Engineer, Irradiation Test Programs, 208-526-8700, Joe.Palmer@INL.gov Affiliation: Idaho National Laboratory P.O. Box 1625, MS-3840 Idaho Falls, ID 83415 INL/CON-10-17680 ABSTRACT Most test reactors are equipped with shuttle facilities (sometimes called rabbit tubes) whereby small capsules can be inserted into the reactor and retrieved during power operations. With the installation of Hydraulic Shuttle Irradiation System (HSIS) this capability has been restored to the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL). The general design and operating principles of this system were patterned after the hydraulic rabbit at Oak Ridge National Laboratory’s (ORNL) High Flux Isotope Reactor (HFIR), which has operated successfully for many years. Using primary coolant as the motive medium the HSIS system is designed to simultaneously transport fourteen shuttle capsules, each 16 mm OD x 57 mm long, to and from the B-7 position of the reactor. The B-7 position is one of the higher flux positions in the reactor with typical thermal and fast (>1 Mev) fluxes of 2.8E+14 n/cm2/sec and 1.9E+14 n/cm2/sec respectively. The available space inside each shuttle is approximately 14 mm diameter x 50 mm long. The shuttle containers are made from titanium which was selected for its low neutron activation properties and durability. Shuttles can be irradiated for time periods ranging from a few minutes to several months. The Send and Receive Station (SRS) for the HSIS is located 2.5 m deep in the ATR canal which allows irradiated shuttles to be easily moved from the SRS to a wet loaded cask, or transport pig. The HSIS system first irradiated (empty) shuttles in September 2009 and has since completed a Readiness Assessment in November 2009. The HSIS is a key component of the ATR National Scientific User Facility (NSUF) operated by Battelle Energy Alliance, LLC and is available to a wide variety of university researchers for nuclear fuels and materials experiments as well as medical isotope research and production.

  8. Status and subjects of thermal-hydraulic analysis for next-generation LWRs with passive safety systems

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    The present status and subjects on thermal-hydraulic analysis for next-generation light water reactors (LWRs) with passive safety systems were summarized based on survey results and discussion by subcommittee on improvement of reactor thermal-hydraulic analysis codes under nuclear code committee in Japan Atomic Energy Research Institute. This survey was performed to promote the research of improvement of reactor thermal-hydraulic analysis codes in future. In the first part of this report, the status and subjects on system analysis and those on evaluation of passive safety system performance are summarized for various types of reactor proposed before. In the second part, the status and subjects on multidimensional two-phase flow analysis are reviewed, since the multidimensional analysis was recognized as one of most important subjects through the investigation in the first part. Besides, databases for bubbly flow and annular dispersed flow were explored, those are needed to assess and verify each multidimensional analytical method. The contents in this report are the forefront of thermal-hydraulic analysis for LWRs and those include current findings for the development of multidimensional two-phase flow analytical method. Thus, we expect that the contents can offer various useful information against the improvement of reactor thermal-hydraulic analysis codes in future. (author)

  9. Modeling of safety-relief valves with thermal-hydraulic system computer codes

    International Nuclear Information System (INIS)

    A generic guideline for thermal-hydraulic (T-H) simulation of multiple bank safety relief valves (SRVs) was developed. To test the guideline, the Full Integral Simulation Test (FIST) 6PMC2 was simulated with the consolidated T-H code of US Nuclear Regulatory Commission, TRACE. The FIST-6PMC2 experiment simulates the response of a generic BWR/6 plant to a Main Steam-line Isolation Valve (MSIV) closure without reactor scram. During the test, the high pressure core spray is unavailable and not used. The only inventory make-up system available is the Reactor Core Isolation Cooling (RCIC). The simulation is largely dominated by the transient behavior of the SRVs. In this study, the experimental data was analyzed and used to check the modeling guideline for SRVs. The guideline relies on only the data available prior to an experiment or any other analysis, e.g. valve flow coefficients, inlet hydraulic diameters, etc. The study also revealed deficiencies in the current valve model of the TRACE code which were subsequently corrected. The study demonstrates that the T-H models can simulate the operational behavior of SRVs very accurately while rather simple mistakes can be very damaging at the same time

  10. Wear and Corrosion Resistance of Fe-Based Coatings Reinforced by TiC Particles for Application in Hydraulic Systems

    Science.gov (United States)

    Bobzin, K.; Öte, M.; Linke, T. F.; Malik, K. M.

    2015-10-01

    Thermally sprayed Fe-based coatings reinforced by TiC particles are a cost-effective alternative to carbide coatings such as WC/CoCr, Cr3C2/NiCr, and hard chrome coatings. They feature a good wear resistance and—with sufficient amount of alloying elements like Cr and Ni—also a high corrosion resistance. In hydraulic systems, the piston is usually coated with hard chrome coatings for protection against corrosion and wear. New water-based hydraulic fluids require an adaption of the coating system. In order to investigate the wear and corrosion resistance of Fe/TiC, a novel powder consisting of a FeCr27Ni18Mo3 matrix and 34 wt.% TiC was applied by HVOF and compared to reference samples made of WC/CoCr (HVAF) and hard chrome. Besides an in-depth coating characterization (metallographic analyses, electron microprobe analyzer-EMPA), wear resistance was tested under reverse sliding in a water-based hydraulic fluid. The novel Fe/TiC coatings showed good wear protection properties, which are comparable to conventional coatings like WC/CoCr (HVAF) and electroplated hard chrome coatings. Corrosion resistance was determined by polarization in application-oriented electrolytes (hydraulic fluid at 60 °C, artificial sea water at RT). The corrosion resistance of the investigated iron-based coatings at 60 °C was superior to the references coatings for both hydraulic fluids. Selected coatings were tested in an application-oriented hydraulic test bench with HFC hydraulic fluid (water polymer solutions) showing comparably good wear and corrosion resistance as the hard chrome-coated reference.

  11. Common Control System Vulnerability

    Energy Technology Data Exchange (ETDEWEB)

    Trent Nelson

    2005-12-01

    The Control Systems Security Program and other programs within the Idaho National Laboratory have discovered a vulnerability common to control systems in all sectors that allows an attacker to penetrate most control systems, spoof the operator, and gain full control of targeted system elements. This vulnerability has been identified on several systems that have been evaluated at INL, and in each case a 100% success rate of completing the attack paths that lead to full system compromise was observed. Since these systems are employed in multiple critical infrastructure sectors, this vulnerability is deemed common to control systems in all sectors. Modern control systems architectures can be considered analogous to today's information networks, and as such are usually approached by attackers using a common attack methodology to penetrate deeper and deeper into the network. This approach often is composed of several phases, including gaining access to the control network, reconnaissance, profiling of vulnerabilities, launching attacks, escalating privilege, maintaining access, and obscuring or removing information that indicates that an intruder was on the system. With irrefutable proof that an external attack can lead to a compromise of a computing resource on the organization's business local area network (LAN), access to the control network is usually considered the first phase in the attack plan. Once the attacker gains access to the control network through direct connections and/or the business LAN, the second phase of reconnaissance begins with traffic analysis within the control domain. Thus, the communications between the workstations and the field device controllers can be monitored and evaluated, allowing an attacker to capture, analyze, and evaluate the commands sent among the control equipment. Through manipulation of the communication protocols of control systems (a process generally referred to as ''reverse engineering''), an attacker can then map out the control system processes and functions. With the detailed knowledge of how the control data functions, as well as what computers and devices communicate using this data, the attacker can use a well known Man-in-the-Middle attack to perform malicious operations virtually undetected. The control systems assessment teams have used this method to gather enough information about the system to craft an attack that intercepts and changes the information flow between the end devices (controllers) and the human machine interface (HMI and/or workstation). Using this attack, the cyber assessment team has been able to demonstrate complete manipulation of devices in control systems while simultaneously modifying the data flowing back to the operator's console to give false information of the state of the system (known as ''spoofing''). This is a very effective technique for a control system attack because it allows the attacker to manipulate the system and the operator's situational awareness of the perceived system status. The three main elements of this attack technique are: (1) network reconnaissance and data gathering, (2) reverse engineering, and (3) the Man-in-the-Middle attack. The details of this attack technique and the mitigation techniques are discussed.

  12. Gemini MCAO Control System

    OpenAIRE

    Boyer, C.; Sebag, J.; Ellerbroek, B.

    2001-01-01

    The Gemini Observatory is planning to implement a Multi Conjugate Adaptive Optics (MCAO) System as a facility instrument for the Gemini-South telescope. The system will include 5 Laser Guide Stars, 3 Natural Guide Stars, and 3 Deformable mirrors optically conjugated at different altitudes to achieve near-uniform atmospheric compensation over a 1 arc minute square field of view. The control of such a system will be split into 3 main functions: the control of the opto-mechanic...

  13. Drone Control System

    Science.gov (United States)

    1983-01-01

    Drones, subscale vehicles like the Firebees, and full scale retired military aircraft are used to test air defense missile systems. The DFCS (Drone Formation Control System) computer, developed by IBM (International Business Machines) Federal Systems Division, can track ten drones at once. A program called ORACLS is used to generate software to track and control Drones. It was originally developed by Langley and supplied by COSMIC (Computer Software Management and Information Center). The program saved the company both time and money.

  14. Discrete Control Systems

    OpenAIRE

    Lee, Taeyoung; Leok, Melvin; McClamroch, N. Harris

    2007-01-01

    Discrete control systems, as considered here, refer to the control theory of discrete-time Lagrangian or Hamiltonian systems. These discrete-time models are based on a discrete variational principle, and are part of the broader field of geometric integration. Geometric integrators are numerical integration methods that preserve geometric properties of continuous systems, such as conservation of the symplectic form, momentum, and energy. They also guarantee that the discrete ...

  15. RBF neural network PID for Bilateral Servo Control System

    OpenAIRE

    Zhang Jingdong; Wen Guang; Wei Yongqiao; Yin Guofu

    2013-01-01

    Tele-operated bilateral hydraulic servo system with master-slave robot at the core can be complex manipulated in uncertain or extreme environment (such as space, seabed, radicalization, battlefield, etc.). In this paper, a novel force feedback bilateral servo system is presented, based on analysis of bilateral servo system at home and abroad, which adopts tuning PID control algorithm with RBF neural network at the same time. From the simulation results, the novel force feedback bilateral se...

  16. Stepless control system for reciprocating compressors: energy savings + process control improvement

    Energy Technology Data Exchange (ETDEWEB)

    Grande, Alvaro; Wenisch, Markus [Hoerbiger Ventilwerke GmbH and Co KG, Wien (Austria); Jacobs, Denis [HOERBIGER do Brasil Industria de Equipamentos, Cajamar, SP (Brazil)

    2012-07-01

    In the past, the capacity of reciprocating compressors was typically controlled by on/off unloaders (step-control) and recycle valves. But due to the fact that the power ratings of new reciprocating compressors for the oil and gas industry increase significantly, advanced control systems are required to reduce power costs and save energy. On top of that, multi-stage compressors are frequently integrated into complex process plants that demand precise control and operational flexibility. There are several solutions for this equation, but maybe the most successful is the use of the reverse flow principle applied to an electronically controlled and hydraulically actuated suction valve unloaders system. (author)

  17. SIMULACIÓN DE UN LAVADO HIDRÁULICO EN TUBERÍAS PARA EL CONTROL DEL CRECIMIENTO DE BIOPELICULA / HYDRAULIC FLUSHING MODELING IN PIPES TO CONTROL OF BIOFILM GROWTH

    Scientific Electronic Library Online (English)

    LUIS F., CARVAJAL; ALEJANDRA, GÓMEZ; SANTIAGO, OCHOA.

    2007-07-01

    Full Text Available Este artículo presenta un problema actual y de gran importancia en los sistemas de acueducto, el cual es la biopelícula que se desarrolla al interior de las paredes de las tuberías y que puede presentar problemas en la calidad del agua y predisposición de los usuarios respecto al servicio público qu [...] e se presta. Se presenta una revisión de los mecanismos físicos que la generan y el control de la biopelícula en tuberías mediante el Lavado Hidráulico. En este caso se hace una simulación hidráulica aplicada a una red que permite conocer si se tienen zonas propensas a la formación de la biopelícula, considerando parámetros de velocidad de flujo y tiempo de permanencia de la zona en condiciones críticas. Se puede estimar si las presiones y velocidades obtenidas están en el rango aceptado por el ente regulador del servicio. Además, se pueden definir criterios de simulación y operación en una red para el control de la biopelícula. Abstract in english The biofilm is associated to water distribution system. It generates serious problems in the water quality and users complaints. This job presents a review of physical processes that origin biofilm and its control by flushing. Simulating different sceneries in pipe networks can define what zones hav [...] e a major formation rate of biofilm than others. The parameters had into account are: pressure, flow velocity and permanency time of zone on critical conditions. The simulating can help to define if pressure and flow velocity are in an operative range according to policy authorities and have hydraulic operation criteria in a pipe network to control the biofilm growth.

  18. System control and communication

    International Nuclear Information System (INIS)

    Rapid and ongoing development in the energy sector has consequences for system control at all levels. In relation to system control and communication the control system is challenged in five important ways: 1) Expectations for security of supply, robustness and vulnerability are becoming more stringent, and the control system plays a big part in meeting these expectations. 2) Services are becoming increasingly based on markets that involve the transmission system operators (TSOs), generators and distribution companies. Timely, accurate and secure communication is essential to the smooth running of the markets. 3) Adding large amounts of renewable energy (RE) to the mix is a challenge for control systems because of the intermittent availability of many RE sources. 4) Increasing the number of active components in the system, such as small CHP plants, micro-CHP and intelligent loads, means that the system control will be much more complex. 5) In the future it is likely that power, heat, gas, transport and communication systems will be tighter coupled and interact much more. (au)

  19. The CEBAF control system

    International Nuclear Information System (INIS)

    CEBAF has recently upgraded its accelerator control system to use EPICS, a control system toolkit being developed by a collaboration among laboratories in the US and Europe. The migration to EPICS has taken place during a year of intense commissioning activity, with new and old control systems operating concurrently. Existing CAMAC hardware was preserved by adding a CAMAC serial highway link to VME; newer hardware developments are now primarily in VME. Software is distributed among three tiers of computers: first, workstations and X terminals for operator interfaces and high level applications; second, VME single board computers for distributed access to hardware and for local control processing; third, embedded processors where needed for faster closed loop operation. This system has demonstrated the ability to scale EPICS to controlling thousands of devices, including hundreds of embedded processors, with control distributed among dozens of VME processors executing more than 125,000 EPICS database records. To deal with the large size of the control system, CEBAF has integrated an object oriented database, providing data management capabilities for both low level I/O and high level machine modeling. A new callable interface which is control system independent permits access to live EPICS data, data in other Unix processes, and data contained in the object oriented database

  20. Development of system analysis code for thermal-hydraulic simulation of integral reactor, Rex-10

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-10-15

    Rex-10 is an environment-friendly and economical small-scale nuclear reactor to provide the energy for district heating as well as the electric power in micro-grid. This integral reactor comprises several innovative concepts supported by advanced primary circuit components, low coolant parameters and natural circulation cooling. To evaluate the system performance and thermal-hydraulic behavior of the reactor, a system analysis code is being developed so that the new designs and technologies adopted in Rex-10 can be reflected. The research efforts are absorbed in programming the simple and fast-running thermal-hydraulic analysis software. The details of hydrodynamic governing equations component models and numerical solution scheme used in this code are presented in this paper. On the basis of one-dimensional momentum integral model, the models of point reactor neutron kinetics for thorium-fueled core, physical processes in the steam-gas pressurizer, and heat transfers in helically coiled steam generator are implemented to the system code. Implicit numerical scheme is employed to momentum and energy equations to assure the numerical stability. The accuracy of simulation is validated by applying the solution method to the Rex-10 test facility. Calculated natural circulation flow rate and coolant temperature at steady-state are compared to the experimental data. The validation is also carried out for the transients in which the sudden reduction in the core power or the feedwater flow takes place. The code's capability to predict the steady-state flow by natural convection and the qualitative behaviour of the primary system in the transients is confirmed. (Author)

  1. Cradle modification for hydraulic ram

    International Nuclear Information System (INIS)

    The analysis of the cradle hydraulic system considers stress, weld strength, and hydraulic forces required to lift and support the cradle/pump assembly. The stress and weld strength of the cradle modifications is evaluated to ensure that they meet the requirements of the American Institute for Steel Construction (AISC 1989). The hydraulic forces are evaluated to ensure that the hydraulic system is capable of rotating the cradle and pump assembly to the vertical position (between 70 degrees and 90 degrees)

  2. ISTTOK control system upgrade

    International Nuclear Information System (INIS)

    Highlights: •ISTTOK fast controller. •All real-time diagnostic and actuators were integrated in the control platform. •100 ?s control cycle under the MARTe framework. •The ISTTOK control system upgrade provides reliable operation with an improved operational space. -- Abstract: The ISTTOK tokamak (Ip = 4 kA, BT = 0.5 T, R = 0.46 m, a = 0.085 m) is one of the few tokamaks with regular alternate plasma current (AC) discharges scientific programme. In order to improve the discharge stability and to increase the number of AC discharge cycles a novel control system was developed. The controller acquires data from 50 analog-to-digital converter (ADC) channels of real-time diagnostics and measurements: tomography, Mirnov coils, interferometer, electric probes, sine and cosine probes, bolometer, current delivered by the power supplies, loop voltage and plasma current. The system has a control cycle of 100 ?s during which it reads all the diagnostics connected to the advanced telecommunications computing architecture (ATCA) digitizers and sends the control reference to ISTTOK actuators. The controller algorithms are executed on an Intel® Q8200 chip with 4 cores running at 2.33 GHz and connected to the I/O interfaces through an ATCA based environment. The real-time control system was programmed in C++ on top of the Multi-threaded Application Real-Time executor (MARTe). To extend the duration of the AC discharges and the plasma stability a new magnetising field power supply was commissioned and the horizontal and vertical field power supplies were also upgraded. The new system also features a user-friendly interface based on HyperText Markup Language (HTML) and Javascript to configure the controller parameters. This paper presents the ISTTOK control system and the consequent update of real-time diagnostics and actuators

  3. ISTTOK control system upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Ivo S., E-mail: ivoc@ipfn.ist.utl.pt; Duarte, Paulo; Fernandes, Horácio; Valcárcel, Daniel F.; Carvalho, Pedro J.; Silva, Carlos; Duarte, André S.; Neto, André; Sousa, Jorge; Batista, António J.N.; Carvalho, Bernardo B.

    2013-10-15

    Highlights: •ISTTOK fast controller. •All real-time diagnostic and actuators were integrated in the control platform. •100 ?s control cycle under the MARTe framework. •The ISTTOK control system upgrade provides reliable operation with an improved operational space. -- Abstract: The ISTTOK tokamak (Ip = 4 kA, BT = 0.5 T, R = 0.46 m, a = 0.085 m) is one of the few tokamaks with regular alternate plasma current (AC) discharges scientific programme. In order to improve the discharge stability and to increase the number of AC discharge cycles a novel control system was developed. The controller acquires data from 50 analog-to-digital converter (ADC) channels of real-time diagnostics and measurements: tomography, Mirnov coils, interferometer, electric probes, sine and cosine probes, bolometer, current delivered by the power supplies, loop voltage and plasma current. The system has a control cycle of 100 ?s during which it reads all the diagnostics connected to the advanced telecommunications computing architecture (ATCA) digitizers and sends the control reference to ISTTOK actuators. The controller algorithms are executed on an Intel{sup ®} Q8200 chip with 4 cores running at 2.33 GHz and connected to the I/O interfaces through an ATCA based environment. The real-time control system was programmed in C++ on top of the Multi-threaded Application Real-Time executor (MARTe). To extend the duration of the AC discharges and the plasma stability a new magnetising field power supply was commissioned and the horizontal and vertical field power supplies were also upgraded. The new system also features a user-friendly interface based on HyperText Markup Language (HTML) and Javascript to configure the controller parameters. This paper presents the ISTTOK control system and the consequent update of real-time diagnostics and actuators.

  4. Design and hydraulic modelling of bentonite elements for shaft sealing systems

    International Nuclear Information System (INIS)

    Document available in extended abstract form only. Shaft sealing systems for repository mines often include bentonite sealing elements. The dimensioning of the bentonite sealing elements on the one hand and the hydraulic modelling of the complete system including the host rock, the contact zone between bentonite and host rock, and the EDZ on the other hand are important steps during the development of shaft sealing systems. The key parameter is the tolerable maximum of the integral fluid flow through the sealing element, the contact zone, and the EDZ. A swelling pressure of > 1 MPa guaranties the tightness of the contact zone between bentonite and host rock. Therefore, the main input parameters for calculations are the thickness and the effective permeability of the EDZ. For the saturated bentonite element, the necessary relative length Ls/As can be calculated for the tolerable fluid flow Qmax. All hydraulic parameters (permeability of sealing material kf,S and the EDZ kf,R, radius of the sealing element R and thickness of the EDZ x) are summarized in the dimensionless parameter G. Theoretically, the resulting swelling pressure developing in the sealing element as well as its permeability depend on the effective dry density of the bentonite. As shown by experiments, the swelling pressure developing in the bentonite material is mainly influenced by its smectite content, the initial water saturation, and the chemical composition of the liquid. A first evaluation of known results of swelling pressure and permeability experiments leads to a correlation of swelling pressure versus smectite content normalized to the pore volume. The scattering of parameters is caused by the variety of influencing processes, i.e. type of liquid, initial water content, test method, type of material, additive. Despite these influences, it seems to be possible to find a well founded regression in order to predict the swelling pressure as a basis for the sealing design. It is necessary and it seems to be possible to find dependencies in this way for the other flow-relevant parameters, e.g. gas and liquid (brine) permeability, capillary pressure, and gas breakthrough (threshold) pressure. Although the focus is on liquid flow processes, gas flow through a shaft sealing system in rock salt should be considered, too. An increase in gas pressure at the bottom of a shaft sealing system cannot be excluded. This will mainly be caused by progressive convergence in the mine and partly by gas producing reactions (remaining artificial material). The pore pressure in the saturated and unsaturated swellable bentonite results from interactions between the capillary pressure (capillary suction) and the swelling pressure. Therefore, understanding and modelling gas and fluid flow processes in the bentonite sealing elements requires representative parameters for, e.g., swelling pressure, gas breakthrough pressure, capillary pressure, porosity, and pore size distribution for the initial and completely saturated state. The entirety of the processes and interactions during progressive saturation and swelling, additionally influenced by compaction processes of the bentonite and convergence of the host rock, are very complicated. When assessing the hydraulic processes and the model based prediction, further effects have to be evaluated: density change due to compaction of the bentonite element, rise of gas pressure and beginning of gas flow, heterogeneous distribution of parameters (e.g. density, porosity, saturation, permeability), and impairment of the sealing performance due to the higher permeability of the contact zone. Based on representative input parameters the dominant flow processes under unsaturated and saturated conditions must be analysed, taking into account the time-dependent pressure on both sides of the sealing system. Hydraulic modelling has already been performed for small-scale pilot sealing tests as well as for a large-scale bentonite sealing element in the shaft sealing experiment Salzdetfurth. The new project 'Sealing systems for radioactive waste r

  5. Electric and hydraulic hybrid actuator. Competing and complementary systems?; Elektrische und hydraulische Hybridantriebe. Konkurrierende oder komplementaere Systeme?

    Energy Technology Data Exchange (ETDEWEB)

    Dehnert, Klaus [Eaton Corporation, Rastatt (Germany)

    2011-07-01

    Hybrid drives for commercial vehicles and for mobile processing machines are evolving rapidly to a future-oriented technology. Hybrid drives significantly affect issues such as fuel efficiency, emissions, productivity and life cycle cost. For recovery and storage of kinetic energy, different technologies are used. Under this aspect, the author of the contribution under consideration reports on the key distinguishing features of some currently available hybrid concepts and their appropriate application. In the selection of suitable hydraulic hybrid drive systems, the essential features of different hybrid systems have to be considered.

  6. The control system

    International Nuclear Information System (INIS)

    The present control system has matured both in terms of age and capacity. Thus a new system based on a local area network (LAN) is being developed. A pilot project has been started but, owing to difficulties encountered with the present operating system used with the microprocessors, it has become necessary to reconsider the choice of operating system. A recently-released multi-tasking operating system that runs on the existing hardware has been chosen. 1 fig

  7. Sharing control system software

    International Nuclear Information System (INIS)

    Building a custom accelerator control system requires effort in the range of 30-100 person-years. This represents a significant investment of time, effort, and risk, as well as challenges for management. Even when the system is successful, the software has not yet been applied to the particular project; no custom control algorithms, either engineering or physics-based, have been implemented; and the system has not been documented for long-term maintenance and use. This paper reviews the requirements for sharing software between accelerator control system projects. It also reviews the three mechanisms by which control system software has been shared in the past and is being shared now, as well as some of the experiences. After reviewing the mechanisms and experiences, one can conclude there is no one best solution. The right software sharing mechanism depends upon the needs of the client site, the client resources available, and the services the provider can give

  8. Vibration of hydraulic machinery

    CERN Document Server

    Wu, Yulin; Liu, Shuhong; Dou, Hua-Shu; Qian, Zhongdong

    2013-01-01

    Vibration of Hydraulic Machinery deals with the vibration problem which has significant influence on the safety and reliable operation of hydraulic machinery. It provides new achievements and the latest developments in these areas, even in the basic areas of this subject. The present book covers the fundamentals of mechanical vibration and rotordynamics as well as their main numerical models and analysis methods for the vibration prediction. The mechanical and hydraulic excitations to the vibration are analyzed, and the pressure fluctuations induced by the unsteady turbulent flow is predicted in order to obtain the unsteady loads. This book also discusses the loads, constraint conditions and the elastic and damping characters of the mechanical system, the structure dynamic analysis, the rotor dynamic analysis and the system instability of hydraulic machines, including the illustration of monitoring system for the instability and the vibration in hydraulic units. All the problems are necessary for vibration pr...

  9. What is system control?

    Energy Technology Data Exchange (ETDEWEB)

    Hirst, E.; Kirby, B.

    1999-11-01

    Just as the aviation industry needs air-traffic controllers to manage the movement of airplanes for safety and commerce, so too, the electricity industry requires system operators. The electrical-system-control functions encompass a range of activities that support commercial transactions and maintain bulk-power reliability. As part of a project for the Edison Electric Institute, the authors examined the functions and costs of system control and the issues that need to be resolved in a restructured electricity industry (Hirst and Kirby 1998).

  10. Underwater Robot Control Systems

    Directory of Open Access Journals (Sweden)

    Govindarajan.R

    2013-04-01

    Full Text Available In this Paper, we introduce three types of enhanced wireless control systems for when the Robot operates under water. The first system is Zigbee communication, second System is Light approach and third one is Magnetic Field. In recent trends the robots are working in vast applications, if our concept adopted, it will enhance and increasing monitoring function done by the robot.

  11. Underwater Robot Control Systems

    OpenAIRE

    Govindarajan.R; Arulselvi.S; Thamarai P

    2013-01-01

    In this Paper, we introduce three types of enhanced wireless control systems for when the Robot operates under water. The first system is Zigbee communication, second System is Light approach and third one is Magnetic Field. In recent trends the robots are working in vast applications, if our concept adopted, it will enhance and increasing monitoring function done by the robot.

  12. 46 CFR 28.880 - Hydraulic equipment.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Hydraulic equipment. 28.880 Section 28.880 Shipping... INDUSTRY VESSELS Aleutian Trade Act Vessels § 28.880 Hydraulic equipment. (a) Each hydraulic system must be... times the system's maximum operating pressure. (c) Each hydraulic system must be equipped with at...

  13. 46 CFR 28.405 - Hydraulic equipment.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Hydraulic equipment. 28.405 Section 28.405 Shipping... Operate With More Than 16 Individuals on Board § 28.405 Hydraulic equipment. (a) Each hydraulic system... than four times the system maximum operating pressure. (c) Each hydraulic system must be equipped...

  14. Keck Telescope Control System

    Science.gov (United States)

    Lupton, W. F.

    The two 10m Keck telescopes run identical control systems, implemented using the Experimental Physics and Industrial Control System (EPICS). The new Adaptive Optics (AO) and Interferometer projects are also partly based on EPICS. However, other observatory subsystems, including acquisition and guiding, primary mirror control, and all the instruments, do not use EPICS. To manage this heterogeneous mix, the high level keyword-oriented Keck Task Library (KTL) was implemented. KTL can run on top of multiple message systems and allows a common API to be used for control, coordination and monitoring of all observatory subsystems. This paper describes several aspects of Keck observatory software, concentrating on interfaces, infrastructure and technologies rather than on technical details. First of all, KTL is introduced, using the telescope control system as an example and illustrating how it was possible to move from the old pre-EPICS Keck 1 control system to the new EPICS control system with hardly any changes to the KTL keyword interface. Next, software for AO and the Interferometer (which uses AO) is described, with an emphasis on automation and the management of complexity. Finally, some new developments are discussed, notably the increasing use of Java and the move towards the use of CORBA.

  15. Development and control towards a parallel water hydraulic weld/cut robot for machining processes in ITER vacuum vessel

    International Nuclear Information System (INIS)

    This paper presents a special robot, able to carry out welding and machining processes from inside the ITER vacuum vessel (VV), consisting of a five degree-of-freedom parallel mechanism, mounted on a carriage driven by two electric motors on a rack. The kinematic design of the robot has been optimised for ITER access and a hydraulically actuated pre-prototype built. A hybrid controller is designed for the robot, including position, speed and pressure feedback loops to achieve high accuracy and high dynamic performances. Finally, the experimental tests are given and discussed

  16. EAST plasma control system

    International Nuclear Information System (INIS)

    Experimental advanced superconducting tokamak (EAST), the first tokomak with ITER-like fully superconductive poloidal and toroidal coils, successfully completed its engineering commission in March 2006; had its first plasma in September 2006 [B.N. Wan, et al., The first plasma of EAST, in: 21st IAEA Fusion Energy Conference, Chengdu, China, 16-21 October, 2007. ] and further generated diverted plasma in January 2007. The plasma control system was adapted from DIII-D plasma control system architecture and jointly developed by the DIII-D and EAST plasma control team. After briefly outlining the hardware and software architecture of the EAST plasma control system, this paper summarizes the plasma control results in the first plasma and first diverted plasma campaigns

  17. Control systems under attack?

    CERN Document Server

    Lüders, Stefan

    2005-01-01

    The enormous growth of the Internet during the last decade offers new means to share and distribute both information and data. In Industry, this results in a rapprochement of the production facilities, i.e. their Process Control and Automation Systems, and the data warehouses. At CERN, the Internet opens the possibility to monitor and even control (parts of) the LHC and its four experiments remotely from anywhere in the world. However, the adoption of standard IT technologies to Distributed Process Control and Automation Systems exposes inherent vulnerabilities to the world. The Teststand On Control System Security at CERN (TOCSSiC) is dedicated to explore the vulnerabilities of arbitrary Commercial-Of-The-Shelf hardware devices connected to standard Ethernet. As such, TOCSSiC should discover their vulnerabilities, point out areas of lack of security, and address areas of improvement which can then be confidentially communicated to manufacturers. This paper points out risks of accessing the Control and Automa...

  18. Reset Control Systems

    CERN Document Server

    Bańos, Alfonso

    2012-01-01

    Reset Control Systems addresses the analysis for reset control treating both its basic form which requires only that the state of the controller be reinitialized to zero (the reset action) each time the tracking error crosses zero (the reset condition), and some useful variations of the reset action (partial reset with fixed or variable reset percentage) and of the reset condition (fixed or variable reset band and anticipative reset). The issues regarding reset control – concepts and motivation; analysis tools; and the application of design methodologies to real-world examples – are given comprehensive coverage. The text opens with an historical perspective which moves from the seminal work of the Clegg integrator and Horowitz FORE to more recent approaches based on impulsive/hybrid control systems and explains the motivation for reset compensation. Preliminary material dealing with notation, basic definitions and results, and with the definition of the control problem under study is also included. The fo...

  19. Control of complex systems

    CERN Document Server

    Albertos, Pedro; Blanke, Mogens; Isidori, Alberto; Schaufelberger, Walter; Sanz, Ricardo

    2001-01-01

    The world of artificial systems is reaching complexity levels that es­ cape human understanding. Surface traffic, electricity distribution, air­ planes, mobile communications, etc. , are examples that demonstrate that we are running into problems that are beyond classical scientific or engi­ neering knowledge. There is an ongoing world-wide effort to understand these systems and develop models that can capture its behavior. The reason for this work is clear, if our lack of understanding deepens, we will lose our capability to control these systems and make they behave as we want. Researchers from many different fields are trying to understand and develop theories for complex man-made systems. This book presents re­ search from the perspective of control and systems theory. The book has grown out of activities in the research program Control of Complex Systems (COSY). The program has been sponsored by the Eu­ ropean Science Foundation (ESF) which for 25 years has been one of the leading players in stimula...

  20. Hydraulic matematical model of drinking water supply system of town piran

    OpenAIRE

    Brežan, Tadej

    2009-01-01

    In my project I have built a hydraulic model of town Piran and compared it with the actual measurement of flow and pressure in this region. Hydraulic model is made on the basis of GIS database from land register of Rižanski vodovod Koper. Using the program EPANET 2.0 I have simulated hydraulic conditions of one-day`s measurement and of the fire protection demand, based on the hydraulic model for region town Piran. Data on actual measurement of flow and pressure in this region h...