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Sample records for hydraulic control systems

  1. Control rod drive hydraulic system

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

  2. Hydraulically powered dissimilar teleoperated system controller design

    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. Hydraulic loop: practices using open control systems

    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)

  4. Towards Autonomous Control of Hydraulic Actuator Systems

    Hansen, Poul Erik; Conrad, Finn

    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....

  5. Towards Autonomous Control of Hydraulic Actuator Systems

    Hansen, Poul Erik; Conrad, Finn

    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...

  6. HYDRAULIC CONCRETE COMPOSITION AND PROPERTIES CONTROL SYSTEM

    O. M. Pshinko; A. V. Krasnyuk; O. V. Hromova

    2015-01-01

    Purpose. Scientific work aims at the development and testing of information system to meet the challenges of concrete composition design and control (for railway structures and buildings) based on the physico-analytical method algorithm for hydraulic concrete composition calculation. Methodology. The proposed algorithm of hydraulic concrete composition calculation is based on the physicochemical mechanics and in particular on the rheology of elastic–viscous–plastic bodies. The system of canon...

  7. Observer-based robust control for hydraulic velocity control system

    Wei Shen; Jihai Jiang; Hamid Reza Karimi; Xiaoyu Su

    2013-01-01

    This paper investigates the problems of robust stabilization and robust control for the secondary component speed control system with parameters uncertainty and load disturbance. The aim is to enhance the control performance of hydraulic system based on Common Pressure Rail (CPR). Firstly, a mathematical model is presented to describe the hydraulic control system. Then a novel observer is proposed, and an observed-based control strategy is designed such that the closed-loop system is asymptot...

  8. Hydraulic system for driving control rod

    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.)

  9. Robust control of hydraulically operated gimbal system

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

  10. Pressure control of hydraulic servo system using proportional control valve

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

  11. Simulation of dynamics of hydraulic system with proportional control valve

    Bureček Adam; Hružík Lumír; Vašina Martin

    2016-01-01

    Dynamics of a hydraulic system is influenced by several parameters, in this case mainly by proportional control valve, oil bulk modulus, oil viscosity, mass load etc. This paper will be focused on experimental measurement and mathematical simulation of dynamics of a hydraulic system with proportional control valve, linear hydraulic cylinder and mass load. The measurement is performed on experimental equipment that enables realization of dynamic processes of the hydraulic system. Linear hydrau...

  12. Modeling, Simulation and Control of Hydraulic Winch System

    Skjong, Stian

    2014-01-01

    In this thesis a hydraulic low pressure winch system has been modeled using bond graph theory. The hydraulic winch system is assumed to be installed on an offshore vessel affected by environmental forces and disturbances such as waves and currents. The hydraulic system powering the winch consists mainly of two pilot operated 3/3-directional valves controlled by two 4/3-directional valves and a hydraulic motor. The system also includes a pressure relief valve, check valves, pump systems, pipin...

  13. Control issues for a hydraulically powered dissimilar teleoperated system

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

  14. HYDRAULIC CONCRETE COMPOSITION AND PROPERTIES CONTROL SYSTEM

    O. M. Pshinko

    2015-08-01

    Full Text Available Purpose. Scientific work aims at the development and testing of information system to meet the challenges of concrete composition design and control (for railway structures and buildings based on the physico-analytical method algorithm for hydraulic concrete composition calculation. Methodology. The proposed algorithm of hydraulic concrete composition calculation is based on the physicochemical mechanics and in particular on the rheology of elastic–viscous–plastic bodies. The system of canonical equations consists of the equations for concrete strength, absolute volume, concrete mix consistency as well as the equation for optimal concrete saturation with aggregates while minimizing cement content. The joint solution of these four equations related to composition allows determining for the materials the concrete composition of required strength, concrete workability with minimum cement content. The procedure for calculation of hydraulic concrete composition according to the physico-analytical method consists of two parts: 1 physical, which is laboratory testing of concrete mix components in different concrete compositions; 2 analytical, which represents the calculation algorithm for concrete compositions equivalent in concrete strength and workability that comply with the specific conditions of concrete placing. Findings. To solve the problem of designing the concrete composition with the desired properties for railway structures and buildings it was proposed to use the information technology in the form of a developed computer program whose algorithm includes the physico-analytical method for hydraulic concrete composition determination. Originality. The developed concrete composition design method takes into account the basic properties of raw materials, concrete mix and concrete, which are pre-determined. The distinctive feature of physico-analytical method is obtaining of a set of equivalent compositions with a certain concrete mix consistency and required concrete strength, which allows to optimize the concrete composition by any optimality criterion, depending on the operation conditions. Practical value. Using the developed method will expand its functionality when applied in the form of the composition calculation computer program for the construction and repair of surface and underwater structures. The use of physico-analytical method at production site will simultaneously solve the economic problems of construction and maintenance cost reduction, component saving and ensure obtaining the concrete with the set properties for specific operation conditions of transport engineering structures.

  15. Control Reconfigurability of Bilinear Hydraulic Drive Systems

    Shaker, Hamid Reza; Tahavori, Maryamsadat

    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 ......-based analogous counterpart, which has been previously proposed for the linear processes. The control reconfigurability is calculated for the bilinear models of an electro-hydraulic drive to show its relevance to redundant actuating capabilities in the models....

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

    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.

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

    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

  18. Simulation of dynamics of hydraulic system with proportional control valve

    Bureček, Adam; Hružík, Lumír; Vašina, Martin

    2016-03-01

    Dynamics of a hydraulic system is influenced by several parameters, in this case mainly by proportional control valve, oil bulk modulus, oil viscosity, mass load etc. This paper will be focused on experimental measurement and mathematical simulation of dynamics of a hydraulic system with proportional control valve, linear hydraulic cylinder and mass load. The measurement is performed on experimental equipment that enables realization of dynamic processes of the hydraulic system. Linear hydraulic cylinder with mass load is equipped with position sensor of piston. The movement control of piston rod is ensured by the proportional control valve. The equipment enables to test an influence of parameter settings of regulator of the proportional control valve on position and pressure system responses. The piston position is recorded by magnetostrictive sensor that is located in drilled piston rod side of the linear hydraulic cylinder. Pressures are measured by piezoresistive sensors on the piston side and the piston rod side of the hydraulic cylinder. The measurement is performed during movement of the piston rod with mass load to the required position. There is realized and verified a mathematical model using Matlab SimHydraulics software for this hydraulic system.

  19. Simulation of dynamics of hydraulic system with proportional control valve

    Bureček Adam

    2016-01-01

    Full Text Available Dynamics of a hydraulic system is influenced by several parameters, in this case mainly by proportional control valve, oil bulk modulus, oil viscosity, mass load etc. This paper will be focused on experimental measurement and mathematical simulation of dynamics of a hydraulic system with proportional control valve, linear hydraulic cylinder and mass load. The measurement is performed on experimental equipment that enables realization of dynamic processes of the hydraulic system. Linear hydraulic cylinder with mass load is equipped with position sensor of piston. The movement control of piston rod is ensured by the proportional control valve. The equipment enables to test an influence of parameter settings of regulator of the proportional control valve on position and pressure system responses. The piston position is recorded by magnetostrictive sensor that is located in drilled piston rod side of the linear hydraulic cylinder. Pressures are measured by piezoresistive sensors on the piston side and the piston rod side of the hydraulic cylinder. The measurement is performed during movement of the piston rod with mass load to the required position. There is realized and verified a mathematical model using Matlab SimHydraulics software for this hydraulic system.

  20. Adaptive Non-linear Control of Hydraulic Actuator Systems

    Hansen, Poul Erik; Conrad, Finn

    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).......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)....

  1. Design of Transputer Controllers for Hydraulic Actuator Systems

    Conrad, Finn

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

  2. Electro-hydraulic control systems for use in mineral mining

    Kussel, W.; Konig, J.; Reuter, M.

    1988-11-16

    An electro-hydraulic control system for a mineral mining installation which includes a valve unit with a plurality of electromagnetic valves which are electrically actuatable by a remote control unit; wherein the valve unit is connected to a current supply common to all the electromagnetic valves and an electronic actuator is provided which is actuatable by the control unit through a data bus to switch the electromagnetic valves electrically, individually or in groups.

  3. Ringhals 2 steam control system reliability/thermal-hydraulic analysis

    This paper evaluates the reliability of the proposed Westinghouse Distributed Processing Family (WDPF) control system and compares it to the reliability of the existing mechanical/ hydraulic control system at the Ringhals 2 nuclear power plant. The probabilities of the postulated failures in the existing control system are contrasted to those that would exist for the WDPF enhanced control and protection system. This paper is limited to a discussion about the reliability that relates to failures that have the potential to cause an overpressure in the moisture separator/reheaters (MSRs) of the Ringhals 2 plant. This power plant was built at a time when the requirements (in Sweden) did not include overpressure relief valves in the MSR. When the plant was originally constructed, the mechanical/ hydraulic control system was designed to be, and was used as, a method to prevent an overpressure condition in the MSR. The control system response time was fast enough to close the MSR inlet lines in the event that one or more discharge line valves was closed or failed closed. The authors also include a thermal-hydraulic analysis of some of the postulated (very low probability) secondary-side transients

  4. Seismic analysis of hydraulic control rod driving system

    A simplified mathematical model was developed for the Hydraulic Control Rod Driving System (HCRDS) of a 200 MW nuclear heating reactor, which incorporated the design of its chamfer-hole step cylinder, to analyze its seismic response characteristics. The control rod motion was analyzed for different sine-wave vibration loadings on platform vibrator. The vibration frequency domain and the minimum acceleration amplitude of the control rod needed to cause the control rod to step to its next setting were compared with the design acceleration amplitude spectrum. The system design was found to be safety within the calculated limits. The safety margin increased with increasing frequency. (author)

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

    Choux, Martin

    -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...

  6. Hydraulic engine valve actuation system including independent feedback control

    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.

  7. Modification Of Control System For Flow On Hydraulic Rabbit System Facility

    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

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

    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.)

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

    Choux, Martin; Karimi, Hamid Reza; Hovland, Geir; Hansen, Michael Rygaard; Ottestad, Morten; Blanke, Mogens

    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 co...

  10. Contamination Control and Monitoring of Tap Water as Fluid in Industrial Tap Water Hydraulic Systems

    Conrad, Finn; Adelstorp, Anders

    1998-01-01

    Presentation of results and methods addressed to contamination control and monitoring of tap water as fluid in tap water hydraulic systems.......Presentation of results and methods addressed to contamination control and monitoring of tap water as fluid in tap water hydraulic systems....

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

    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.

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

    Conrad, Finn

    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....

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

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

    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...

  14. The hydraulic driving system for control rods on 5 MW district heating reactor (DHR)

    The hydraulic step driving sysem is used for driving of control rods on the 5 MW DHR. The system is based on a new concept of control rod driving, which is different from electric-magnetic-mechanic driving used for PWR. The reactor coolant (water) is used as actuating medium, pressed by pump, and then injected into hydraulic step cylinders which are set in the reactor vessel. The outer tube of the cylinder will be moving step by step by controlling flow, driving the neutron absorber and controlling nuclear reaction. 5MW DHR is the first reactor in the world, in which the hydraulic driving system was used. Utilization of the system is for getting better safety, reliability and economy. The principle of hydraulic step driving, the design and experimental research of the system are described

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

    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.

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

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

    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.

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

    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.......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....

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

    Yang, Xiuqing; Luo, Minzhou; Mei, Tao; Yao, Damao

    2009-06-01

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

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

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

  1. Experimental study of hydraulic driving system of control rod not engendering rod ejection accident

    The hydraulic driving system of control rod is a new controlling-equipment in nuclear reactor. Its drive assembly is hydraulic step cylinder. The cylinder can be installed in the pressure vessel and its inner tube is fixed on the bottom block of core. By the experiment for experimental loop (including pressure vessel, hydraulic step cylinder, heater, pump and another devices) and measuring system, the rod position is measured and observed when the pressure vessel loses pressure under high temperature and high pressure. A lot of experimental data and observed results are obtained. The results indicate: The hydraulic driving system of control rod can not engender rod ejection accident when the pressure vessel loses pressure. So, this system has inherent safety feature of not engendering rod ejection

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

    Wang Yeqin

    2013-06-01

    Full Text Available 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. Finally the simulation is conducted with the typical input signal, such as tracking step, sine etc. The simulation results show that?the self-tuning fuzzy PID control system can effectively improve the dynamic characteristic when the system is out of the range of the operating point compared with the traditional PID control system, there is obvious improvement in the indexes of rapidity, stability and accuracy, and fuzzy self-tuning PID Control is more robust, and more suitable for direct drive electro-hydraulic servo system.

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

    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)

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

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

    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 improved tracking performance for small changes in load pressure. For large changes in load pressure......, active gain feedforward shows a slightly improved performance. Computed-Torque Control shows better performance, but requires a well described system for best performance. A novel Adaptive Inverse Dynamics Controller was tested and the performance was found to be similar to that of Computed...

  5. Electro Hydraulic Hitch Control

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

    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...... for a parameter research study with emphasis on the requirements to the hitch control by use of hydraulic pressure compensated proportional control valve....

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

    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.

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

    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...

  8. Design and Optimization of Controllers for an Electro-Hydraulic System

    André, Simon

    2014-01-01

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

  9. Electro Hydraulic Hitch Control

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

    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...

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

    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

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

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

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

    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.

  13. Digital electro-hydraulic control system for nuclear turbine

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

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

    M. Choux

    2010-01-01

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

  15. The safety feature of hydraulic driving system of control rod for 200 MW nuclear heating reactor

    The hydraulic driving system of control rod is used as control rod drive mechanism in 200 MW nuclear heating reactor. Design of this system is based on passive system, integrating drive and guide of control rod. The author analyzes the inherent safety and the design safety of this system, with mechanism of control rod not ejecting when the pressure of pressure vessel is lost, and calculating result of core not exposing when the amount of coolant is drained by broken pipe. The results indicate that this system has good safety feature, and assures reactor safety under any accident conditions, providing important technology support for 200 MW nuclear heating reactor with inherent safety feature

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

    Choux, Martin; Hovland, Geir; Blanke, Mogens

    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 adapt...

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

    Choux, Martin; Hovland, Geir; Blanke, Mogens

    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...

  18. Controls of Hydraulic Wind Turbine

    Zhang Yin

    2016-01-01

    Full Text Available In this paper a hydraulic wind turbine generator system was proposed based on analysis the current wind turbines technologies. The construction and principles were introduced. The mathematical model was verified using MATLAB and AMsim. A displacement closed loop of swash plate of motor and a speed closed loop of generator were setup, a PID control is introduced to maintain a constant speed and fixed frequency at wind turbine generator. Simulation and experiment demonstrated that the system can connect grid to generate electric and enhance reliability. The control system demonstrates a high performance speed regulation and effectiveness. The results are great significant to design a new type hydraulic wind turbine system.

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

    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

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

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

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

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

    2012-01-01

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

  2. Hydraulic Yaw System

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

    system and rotor shaft when utilizing the soft yaw drive concept compared to the original stiff yaw system. The physical demands of the hydraulic yaw system are furthermore examined for a life time of 20 years. Based on the extrapolated loads, the duty cycles show that it is possible to construct a...... hydraulic soft yaw system, which is able to reduce the loads on the wind turbine significantly. A full scale hydraulic yaw test rig is available for experiments and tests. The test rig is presented as well as the system schematics of the hydraulic yaw system....

  3. Hydraulic reactivity control method

    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.)

  4. The theoretical model on shutdown process of the control rod hydraulic driving system

    The experiment loop and the shutdown process of the Control Rod Hydraulic Driving System have been introduced. Also given are the theoretical model and its accurate mathematical description on base of reasonable simplification and hypothesis. The comparison between the result of this model and that of the experiment proves the rationality and feasibility of this model. This model is important for further analysis and improvement

  5. Theoretical model on stepping process of the hydraulic control rod driving system

    The purpose is to theoretically expound the working mechanism of the new technology of the hydraulic control rod driving system (HCRDS), and also establish the theoretical model for further analysis and research. The working principle of the HCRDS has been introduced, the theoretical model and its mathematical description of the HCRDS's stepping process are also given. The compare between the result of this model and that of the experiment proves the rationality and feasibility of it

  6. Kinematics characters of a hydraulic driving system of control rods under rocking

    The experimental equipment consist of the test object of the hydraulic driving system of control rod (HDSCR), 6-freedom rocking test plate, measure system and control system, which was used to study kinematic characters of HDSCR under rocking. By using this equipment, several experiments were made when the test object followed the rocking test plate to rock: 1) the control rod lifted or fell step by step; 2) the control rod fast fell by gravity. Also, the experiment of control rod fast falling was made when the test object bending angle was 45 degree. Experimental results indicate: 1) HDSCR has favourable moving reliability and inherent safety when rocking angle is less than 35 degree; 2) the control rod can fall smoothly by gravity when bending angle is 45 degree. This system can be satisfied with ship rocking requirements when it will be appropriately changed. This research will provide experimental basis for HDSCR to be used in the ship power reactors

  7. Thermal hydraulic analysis and control of the HELOKA water cooling system

    Helium loop Karlsruhe (HELOKA) is a new test facility, in advanced status of design at the Forschungszentrum Karlsruhe, which will be used to test the helium cooled pebble bed (HCPB) breeder blanket for ITER under realistic pressure, temperature and He flow conditions. A redundant water cooling system, built in the 1980s, with a nominal heat load of 7 MW, will be used to remove the heat from the He loop. The paper describes first the thermo-hydraulic analysis performed on the water cooling system and then new feedback and feed-forward control systems for the electric drivers, based on the actual heat load, to increase efficiency and save energy

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

    Weng, Falu; Mao, Weijie

    2012-03-01

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

  9. Dynamic modelling of pressure control system of a 500 MWe PHWR power plant thermal hydraulics aspects

    A computer code for the dynamic analysis of the proposed 500 MWe Pressurised Heavy Water Reactor is being developed. One of the modules of this code deals with the primary heat transport system pressure control. A thermal hydraulic model of the pressure control system has been developed. This model includes the following : reactor coolant loop, primary circulating pump, Core heat transfer, Feed/bleed with Bleed Condenser and pressure controller. Analysis has been carried out for transients like change in reactor power, leakage from the primary heat transport system and malfunctioning of control system. The mathematical model is presented in the paper along with the results obtained for some of the transients analysed. (author). 6 refs., 6 figs

  10. Water Hydraulic Systems

    Conrad, Finn

    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...

  11. Experiment study on rod ejection accident of hydraulic control rod driving system

    The rod ejection experiment has been done in the 1:1 experiment loop of the hydraulic control rod driving system (HCRDS) of the 200 MW nuclear heating reactor (NHR-200). The result indicated that under different experiment conditions, the control rod was not ejected when the pressure vessel of the loop lost pressure. Based on the depressurization accident analysis of the NHR-200, performed at the Institute of Nuclear Energy Technology (INET), Tsinghua University, the depressurization rate of experiment is much higher than that of analysis. Thus, the HCRDS has inherent safety and no hidden trouble of rod ejection when the depressurization accident happens. (author)

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

    Conrad, Finn; Sørensen, Torben

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

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

    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 as output feedback controllers. However, intrinsic nonlinear dynamic effects of hydraulic valves such...... 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...

  14. Thermal hydraulic system codes

    A short summary is given on the so called thermal hydraulic system codes. Introducing this topic some elementary information is presented on thermal hydraulic phenomena occurring during accidents. Special attention will be paid to two-phase (gas-liquid) flow behavior and to the calculation of flows like that. The basic models of two-phase flow simulation is shown, and making use of the examples of SMABRE and CATHARE codes the main features of thermal hydraulic system codes are listed, including the basic equations, steps of code validation and verification and the cycle of code development strategy. In the conclusions an attempt will be made on the state-of-art description of the limitations and capabilities of thermal hydraulic codes. (author). 5 refs., 7 figs

  15. Electrokinetic high pressure hydraulic system

    Paul, Phillip H.; Rakestraw, David J.; Arnold, Don W.; Hencken, Kenneth R.; Schoeniger, Joseph S.; Neyer, David W.

    2003-06-03

    An electrokinetic high pressure hydraulic pump for manipulating fluids in capillary-based system. The pump uses electro-osmotic flow to provide a high pressure hydraulic system, having no moving mechanical parts, for pumping and/or compressing fluids, for providing valve means and means for opening and closing valves, for controlling fluid flow rate, and manipulating fluid flow generally and in capillary-based systems (microsystems), in particular. The compact nature of the inventive high pressure hydraulic pump provides the ability to construct a micro-scale or capillary-based HPLC system that fulfills the desire for small sample quantity, low solvent consumption, improved efficiency, the ability to run samples in parallel, and field portability. Control of pressure and solvent flow rate is achieved by controlling the voltage applied to an electrokinetic pump.

  16. Fault tree analysis of control rod drop caused by failure of hydraulic system of control rod drive

    Unplanned outage times per year is an important indicator of operation performance for power reactor. The hydraulic system of control rod drives is one of the key systems in a nuclear heating reactor. The unplanned outage will be directly caused by the system failure. The unplanned outage caused by the failure of components in the system will be discussed with the method of fault tree analysis. The issues will be concentrated on the setup of the fault tree, analyzing the probability of topmost event and giving some suggestions on improving the system design based on the fault tree analysis result

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

    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

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

    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.

  19. Thermal hydraulics of the impurity control system for FED/INTOR

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

  20. Plug & Play Control of Hydraulic Networks

    Jensen, Tom Nørgaard

    2012-01-01

    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...

  1. Control rod drive hydraulic device

    The device of the present invention can reliably prevent a possible erroneous withdrawal of control rod driving mechanism when the pressure of a coolant line is increased by isolation operation of hydraulic control units upon periodical inspection for a BWR type reactor. That is, a coolant line is connected to the downstream of a hydraulic supply device. The coolant line is connected to a hydraulic control unit. A coolant hydraulic detection device and a pressure setting device are disposed to the coolant line. A closing signal line and a returning signal line are disposed, which connect the hydraulic supply device and a flow rate control valve for the hydraulic setting device. In the device of the present invention, even if pressure of supplied coolants is elevated due to isolation of hydraulic control units, the elevation of the hydraulic pressure can be prevented. Accordingly, reliability upon periodical reactor inspection can be improved. Further, the facility is simplified and the installation to an existent facility is easy. (I.S.)

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

    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)

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

    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...

  4. Hydraulically driving system for control rod driving mechanism and operation method therefor

    In the present invention, a water-filling line equipped with a pressure gauge is disposed on the discharge side of a pump of an electromotive type control rod driving mechanism (CRD) to be used in a BWR type reactor. The water filling line is connected to a plurality of hydraulic control units by way of a water filling header. The hydraulic control units have an accumulator for containing water in a pressurized state by a pressurized gas. The accumulator is connected to the CRD by way of a scram valve. An orifice is disposed at the downstream of the pressure gauge of the water filling line. With such a constitution, even when pressurized water supplied from the CRD pump is continuously flown passing through the water filling line upon occurrence of scram of a single hydraulic control unit, the pressure reduction of the filling water line can be mitigated by the resistance of the orifice on the downstream of the pressure gauge of the filling line or using a filling water partitioning valve disposed to a filling water pipeline of the single hydraulic control unit in a slightly opened state. Then, actuation of interlock can reliably be prevented. (I.S.)

  5. Hybrid Robust Control Law with Disturbance Observer for High-Frequency Response Electro-Hydraulic Servo Loading System

    Zhiqing Sheng

    2016-04-01

    Full Text Available Addressing the simulating issue of the helicopter-manipulating booster aerodynamic load with high-frequency dynamic load superimposed on a large static load, this paper studies the design of the robust controller for the electro-hydraulic loading system to realize the simulation of this kind of load. Firstly, the equivalent linear model of the electro-hydraulic loading system under assumed parameter uncertainty is established. Then, a hybrid control scheme is proposed for the loading system. This control scheme consists of a constant velocity feed-forward compensator, a robust inner loop compensator based on disturbance observer and a robust outer loop feedback controller. The constant velocity compensator eliminates most of the extraneous force at first, and then the double-loop cascade composition control strategy is employed to design the compensated system. The disturbance observer–based inner loop compensator further restrains the disturbances including the remaining extraneous force, and makes the actual plant tracking a nominal model approximately in a certain frequency range. The robust outer loop controller achieves the desired force-tracking performance, and guarantees system robustness in the high frequency region. The optimized low-pass filter Q(s is designed by using the H∞ mixed sensitivity optimization method. The simulation results show that the proposed hybrid control scheme and controller can effectively suppress the extraneous force and improve the robustness of the electro-hydraulic loading system.

  6. Robust H(∞) positional control of 2-DOF robotic arm driven by electro-hydraulic servo system.

    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

  7. Thermo hydraulic analysis and control of the HELOKA water cooling system

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

  8. Adaptive Sliding Mode Control for Hydraulic Drives

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

    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...

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

    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

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

    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. Modeling, Optimization & Control of Hydraulic Networks

    Tahavori, Maryamsadat

    2014-01-01

    . 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...... 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...

  12. Automatic transmission system for automobiles having hydraulic and electronic control systems

    Nakao, T.; Furukawa, T.; Mori, M.

    1987-03-31

    This patent describes an automatic transmission system in an automobile having an engine, a brake, a throttle valve, a shift lever, a clutch, and transmission gears associated with synchromesh systems. The automatic transmission system comprises: (a) a throttle actuator means for actuating the throttle valve; (b) a clutch actuator means for actuating the clutch; (c) a gear selection actuator means for selectively actuating the synchromesh systems to shift the transmission gear; (d) a fluid pressure control unit means for applying working fluid pressures to the gear selection actuator; and (e) an electronic control unit means for transmitting control signals to the throttle actuator means, the clutch actuator means, and the fluid-pressure control unit means. The signals are sent in response to detected signals indicative of a rotational speed of the engine, an operation of the brake, an operative position of the throttle valve, a selected position of the shift lever, a releasing position of the clutch, and a speed of travel of the automobile.

  13. Control rod driving hydraulic device

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

  14. Hydraulic control rod

    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

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

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

    2013-11-01

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

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

    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)

  17. Hydraulic drives for control rods

    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.)

  18. Process System Hydraulics

    An analysis of hydraulic characteristics of the reactor plenum and the geometry of the permanent tube slots indicates the effect of the plenum pressure gradient on flow is substantially less than has been used previously to determine process water flows from cumulative fuel assembly resistances. This report details results of that study

  19. 14 CFR 29.1435 - Hydraulic systems.

    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...

  20. 14 CFR 23.1435 - Hydraulic systems.

    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...

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

    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...

  2. Hydraulic control unit detection method and device

    The present invention provides detection method and device for ensuring integrity of hydraulic control units of a BWR type power plant and shortening the term for plant periodical inspection. Namely, (1) the integrity of the hydraulic control units is confirmed based on the time required from the input of control rod driving signals to the hydraulic control units to the completion of the control rod operation, (2) the integrity of the hydraulic control units is confirmed based on the driving time per 1 notch of the notches formed on control rods, (3) the above-mentioned integrity is judged by setting the range of the time assumed as integral based on integral data previously measured and determining whether the above-mentioned time is within the predetermined range or not, (4) this operation is conducted during a periodical inspection, and inspection is conducted by disassembling only the hydraulic control unit which is judged to be not integral. (I.S.)

  3. Robust hydraulic position controller by a fuzzy state controller

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

  4. Transputer Control of Hydraulic Actuators and Robots

    Conrad, Finn

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

  5. Investigation of Control Model in a New Series Hybrid Hydraulic/Electric System for Heavy Vehicles Based on Energy Efficiency

    Soroosh Mahmoodi; Hu Guoqing; Mehrdad Nouri Khajavi

    2016-01-01

    An interesting model which was able to recuperate and reuse braking energy was investigated. It was named series hybrid hydraulic/electric system (SHHES). The innovated model was presented for heavy hybrid vehicles to overcome the existing drawbacks of single energy storage sources. The novelty of this paper was investigation of a new series hybrid vehicle with triple sources, combustion engine, electric motor, and hydraulic sources. It was simulated with MATLAB-Simulink and different operati...

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

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

    2002-07-01

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

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

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

  8. Experimental evaluation of control strategies for hydraulic servo robot

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

    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...

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

    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

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

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

    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 towa...

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

    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.

  12. Transputers in Fluid Power - Design and Applications. Chapter 5 in Advances in Hydraulic Control Systems

    Conrad, Finn

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

  13. 14 CFR 27.1435 - Hydraulic systems.

    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...

  14. 14 CFR 25.1435 - Hydraulic systems.

    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. A Robust Adaptive Hydraulic Power Generation System for Jet Engines

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

    2013-01-01

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

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

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

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

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

    1997-10-01

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

  18. Condition Monitoring of Hydraulic Systems

    Zhao, Xiaoyu

    2015-01-01

    The purpose of this project is to investigate and propose a system for condition monitoring and analysis of the hydraulic system of a forestry machine based on available on-board oil quality sensor data. The sample machine used was Scorpion King from Ponsse. This machine is equipped with an Icount PDR particle sensor from Parker. A two weeks long field test was conducted by Skogforsk. The data measured by the particle counter was collected, and breaks longer than five minutes were recorded as...

  19. Crosshole investigations - Design of the hydraulic testing system

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

  20. Concept Evaluation for Hydraulic Yaw System

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

    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...

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

    Pedersen, Henrik Clemmensen

    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...... project to develop rules and methods for designing and controlling mobile hydraulic systems in the most energy efficient way, when also considering the operational aspects of the system. The paper first describes the thoughts and ideas behind the project and then focus on an automated approach to design...... the hydraulic power supply in the most energy efficient way, when considering a number of load situations. Finally an example of the approach is shown to prove its validity.}...

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

    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.

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

    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

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

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

    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...

  5. Operational simulation of redundant output actuator for multiple hydraulic flight control systems; Taju yuatsu soju keito ni okeru jocho shutsuryoku actuator no sado simulation

    Ogawa, T. [National Aerospace Laboratory, Tokyo (Japan)

    1997-05-01

    Aircraft control system is multiplexed to enhance reliability. This means to multiplex the system that conveys steering signals to the control surfaces, and it is desired that all the systems will be simultaneously actuated to counter a control surface angular displacement resulting from a failure in one system. Then the failure in one system will be compensated for by the other two systems in the case of a three-system design, which will allow the sustenance of a nearly normal maneuver. When the simultaneous actuation of all the systems are considered, however, one has to be chosen out of two methods; to arrange all the systems in parallel on the control surfaces or to combine the outputs of all the systems into one while they are on their way to the control surfaces. In this report, the latter type, or a redundant output type hydraulic actuator, is discussed. Although the adding operation of this type is in general described by a block diagram which contains a feedback system that is quite complicated, yet, in this report, it is formulated as a problem of torsional vibration of the output axis to enable easy control system designing. 10 refs., 6 figs., 4 tabs.

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

    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.

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

    Ayman A. Aly

    2012-06-01

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

  8. Development of simulation program for hydraulic control systems using personal computer; Pasokon ni yoru yuatsu seigyokei no dotokusei simulation program kaihatsu

    Muto, T.; Seko, A.; Mori, R. [Gifu University, Gifu (Japan). Faculty of Engineering

    1994-09-15

    This paper reports on the block diagram simulation program (BDSP), which is a kind of the dynamic characteristics simulation program for hydraulic control systems, with respect to the result of developing the first stage that has realized its basic conception. The paper describes the features of the BDSP as follows: simulations can be executed by operating a personal computer using an interaction processing based on a block line chart of the subject system; the program can deal with discrete time systems, different non-linear elements and tube path elements; and with respect to the tube path elements, a calculation method was adopted that approximates each element in the transfer matrix of the distribution constant system being a mathematical model by using a rational multi-term formula proposed by Zhao, et al., in order to achieve a high speed operation. The paper then summarizes the simulation operating procedures using the BDSP (indication of block line charts, inputs of the transfer function, system parameters, and system target values, etc.) It presents the results of simulations on two kinds of tube path system and hydraulic servo system. 7 refs., 19 figs.

  9. Thermal-hydraulic unreliability of passive systems

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

  10. Angle Displacement Robust Controller for the Port Plate of the Hydraulic Transformer

    Wei Shen; Jihai Jiang; Xiaoyu Su; Hamid Reza Karimi

    2013-01-01

    The hydraulic transformer is used in the hydraulic system to enhance the efficiency. However, how to control the angle displacement of the port plate is becoming a critical issue because of the new structure of the hydraulic transformer. This paper presents a new method for the angle displacement control system. Firstly, the basic principle of the system is presented. Then, the disturbance which is mainly the friction torque between the port plate and the cylinder block is calculated to estim...

  11. INFORMATION-MEASURING TEST SYSTEM OF DIESEL LOCOMOTIVE HYDRAULIC TRANSMISSIONS

    I. V. Zhukovytskyy

    2015-08-01

    Full Text Available Purpose. The article describes the process of developing the information-measuring test system of diesel locomotives hydraulic transmission, which gives the possibility to obtain baseline data to conduct further studies for the determination of the technical condition of diesel locomotives hydraulic transmission. The improvement of factory technology of post-repair tests of hydraulic transmissions by automating the existing hydraulic transmission test stands according to the specifications of the diesel locomotive repair enterprises was analyzed. It is achieved based on a detailed review of existing foreign information-measuring test systems for hydraulic transmission of diesel locomotives, BelAZ earthmover, aircraft tug, slag car, truck, BelAZ wheel dozer, some brands of tractors, etc. The problem for creation the information-measuring test systems for diesel locomotive hydraulic transmission is being solved, starting in the first place from the possibility of automation of the existing test stand of diesel locomotives hydraulic transmission at Dnipropetrovsk Diesel Locomotive Repair Plant "Promteplovoz". Methodology. In the work the researchers proposed the method to create a microprocessor automated system of diesel locomotives hydraulic transmission stand testing in the locomotive plant conditions. It acts by justifying the selection of the necessary sensors, as well as the application of the necessary hardware and software for information-measuring systems. Findings. Based on the conducted analysis there was grounded the necessity of improvement the plant hydraulic transmission stand testing by creating a microprocessor testing system, supported by the experience of developing such systems abroad. Further research should be aimed to improve the accuracy and frequency of data collection by adopting the more modern and reliable sensors in tandem with the use of filtering software for electromagnetic and other interference. Originality. The authors developed the information-measuring system that improves the hydraulic transmission test process by automating and increasing the accuracy of measurements of control parameters. The measurement results are initial data for carrying out further studies to determine the technical condition of the hydraulic transmission UGP750-1200 during the plant post-repair tests. Practical value. The paper proposed the alternate design of microprocessor hydraulic transmission test system for diesel locomotives, which has no analogues in Ukraine. Automated data collection during the tests will allow capturing the fast processes to determine the technical condition of hydraulic transmission.

  12. 49 CFR 570.55 - Hydraulic brake system.

    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...

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

    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 {λ,μ}, 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

  14. Computerized hydraulic scanning system for quantitative non destructive examination

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

  15. Technique of multilevel adjustment calculation of the heat-hydraulic mode of the major heat supply systems with the intermediate control stages

    Tokarev, V. V.; Shalaginova, Z. I.

    2016-01-01

    A new technique for heat-hydraulic calculation to organize the normal operating modes of the heat supply systems intended to decide the tasks of planning and mode selecting, which ensures the required thermal loads at adherence of all restrictions on its parameters, is proposed. The main feature of the technique is in the determination of the parameters of throttling devices on the network and inlets into the buildings of consumers taking into account the differentiated corrections to the flow rates on the compensation of the heat losses in the network. The technique involves the decision of the multilevel adjustment calculation task, in which the deviations of the boundary mode parameters (pressure, flow rate, temperature) in place of the decomposition of the heat supply system model on the levels of main and distribution heating networks taking into account the intermediate control stages on the central heat points (CHP) are minimized. At each level, the task of single-level adjustment heat-hydraulic calculation is decided, which is mathematically defined as an optimization task where the internal air temperature deviation is minimized of the required value with the given accuracy a priori. The technique is realized as part of the ANGARA-TS data-computing system and allows developing the adjusting procedures to improve the heat supply quality and availability of heating consumers, determining the minimum necessary values of heads on the sources and pumping stations.

  16. High speed on/off valve control hydraulic propeller

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

    2012-05-01

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

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

    Conrad, Finn

    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...

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

    HUANG, Ye; 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...

  19. Linear Perturbation Adaptive Control of Hydraulically Driven Manipulators

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

    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......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...

  20. Fort St. Vrain hydraulic power system study

    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

  1. Hydraulic model of the systemic resistance

    Leitermann, D.; Pražák, Josef; Musil, Jan; Poušek, L.; Konvičková, 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 ČR(XC) PP50252 Institutional research plan: CEZ:AV0Z2076919 Keywords : systemic resistance * hydraulic model * cardiovascular system Subject RIV: BK - Fluid Dynamics

  2. Hydraulic Regenerative System for a Light Vehicle

    Orpella Aceret, Jordi; Guinart Trayter, Xavier

    2010-01-01

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

  3. Thermal Equilibrium of a Hydraulic Driving System

    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

  4. Water heating system hydraulics. Hydraulik der Wasserheizung

    Roos, H.

    1986-01-01

    Based on a minimum of fluid mechanics principles the manual facilitates access to the effects of hydraulic interventions or circuit manipulations in water heating systems. The book is a valuable vehicle for students and practical engineers. The detailed picture- and table-assisted discussion deals with the following subjects: Hydraulic resistors (tubes and pipes, networks, rheostats and single resistors), hydraulic connection methods (parallel and series connection), practical examples (switch-off of double and single tube heating systems, determination of hydraulic series cut-outs), straight-way valves and network (design and dimensioning), pumps as actuators, three-way valves and network (equivalent circuits, installation, working characteristics), interaction of locally separated pumps (example connection), hydraulic connections (characteristics of combined connections, example), overlaps of pumping action and gravitational effects, four-way mixers (purpose), overflow valves, jet pumps and computers. The final chapter is dedicated to the description of the Tichelmann circuit which is characterized by equal circuit lengths, equal pressure drops in straight tubes and reduced flow noises. With 183 figs., 12 tabs..

  5. Tracking control of the hydraulically actuated flexible manipulator

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

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

    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 understanding and appreciation of that value. The series of IAHR Symposia on Hydraulic Machinery and Cavitation started with the 1st edition in Nice, France, 1960. For the past decade, all the symposia have focused on an extended portfolio of topics under the name of 'Hydraulic Machinery and Systems', such as the 20th edition in Charlotte, USA, 2000, the 21st in Lausanne, Switzerland, 2002, the 22nd in Stockholm, Sweden, 2004, the 23rd in Yokohama, Japan, 2006, the 24th in Foz do Iguassu, Brasil, 2008, and the 25th in Timisoara, Romania, 2010. The 26th IAHR Symposium on Hydraulic Machinery and Systems brings together more than 250 scientists and researchers from 25 countries, affiliated with universities, technology centers and industrial firms to debate topics related to advanced technologies for hydraulic machinery and systems, which will enhance the sustainable development of water resources and hydropower production. The Scientific Committee has selected 268 papers, out of 430 abstracts submitted, on the following topics: (i) Hydraulic Turbines and Pumps, (ii) Sustainable Hydropower, (iii) Hydraulic Systems, (iv) Advances in Computational and Experimental Techniques, (v) Application in Industries and in Special Conditions, to be presented at the symposium and to be included in the proceedings. All the papers, published in this Volume 15 of IOP Conference Series: Earth and Environmental Science, have been peer reviewed through processes administered by the editors of the 26th IAHR Symposium on Hydraulic Machinery and Systems proceedings, those are Yulin Wu, Zhengwei Wang, Shuhong Liu, Shouqi Yuan, Xingqi Luo and Fujun Wang. We sincerely hope that this edition of the symposium will be a significant step forward in the worldwide efforts to address the present challenges facing the modern Hydraulic Machinery and Systems. Professor Yulin Wu Chairman of the Organizing Committee 26th IAHR Symposium on Hydraulic Machinery and Systems

  7. Hydraulics.

    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)…

  8. Geomorphic and hydraulic controls on large-scale riverbank failure on a mixed bedrock-alluvial river system, the River Murray, South Australia: a bathymetric analysis.

    De Carli, E.; Hubble, T.

    2014-12-01

    During the peak of the Millennium Drought (1997-2010) pool-levels in the lower River Murray in South Australia dropped 1.5 metres below sea level, resulting in large-scale mass failure of the alluvial banks. The largest of these failures occurred without signs of prior instability at Long Island Marina whereby a 270 metre length of populated and vegetated riverbank collapsed in a series of rotational failures. Analysis of long-reach bathymetric surveys of the river channel revealed a strong relationship between geomorphic and hydraulic controls on channel width and downstream alluvial failure. As the entrenched channel planform meanders within and encroaches upon its bedrock valley confines the channel width is 'pinched' and decreases by up to half, resulting in a deepening thalweg and channel bed incision. The authors posit that flow and shear velocities increase at these geomorphically controlled 'pinch-points' resulting in complex and variable hydraulic patterns such as erosional scour eddies, which act to scour the toe of the slope over-steepening and destabilising the alluvial margins. Analysis of bathymetric datasets between 2009 and 2014 revealed signs of active incision and erosional scour of the channel bed. This is counter to conceptual models which deem the backwater zone of a river to be one of decelerating flow and thus sediment deposition. Complex and variable flow patterns have been observed in other mixed alluvial-bedrock river systems, and signs of active incision observed in the backwater zone of the Mississippi River, United States. The incision and widening of the lower Murray River suggests the channel is in an erosional phase of channel readjustment which has implications for riverbank collapse on the alluvial margins. The prevention of seawater ingress due to barrage construction at the Murray mouth and Southern Ocean confluence, allowed pool-levels to drop significantly during the Millennium Drought reducing lateral confining support to the over-steepened channel margins triggering large-scale riverbank failure.

  9. Reactor Shutdown Mechanism by Top-mounted Hydraulic System

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

    2012-05-15

    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

  10. Hydraulic fluid properties and its influence on system performance

    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...

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

    Mankamo, T. [Avaplan Oy, Espoo (Finland)

    1996-12-01

    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.

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

    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

  13. Chapter 12. Pure Tap Water Hydraulic Systems and Applications

    Conrad, Finn; Adelstorp, Anders

    Presentation of developed a modern pure tap water hydraulic components (Nessie), systems and industrial applications.......Presentation of developed a modern pure tap water hydraulic components (Nessie), systems and industrial applications....

  14. Instrumentation system for massive hydraulic fracture mapping

    Keck, L.J.; Seavey, R.W.

    1977-04-01

    The measurement of induced surface potentials has been used in a research effort to map the orientation of fractures created by massive hydraulic fracturing. A first generation measurement system has been developed via field testing that has successfully mapped fracture orientation. The design, layout, and operation of the instrumentation system used to generate, measure, and analyze surface potentials during a massive hydrofracture are described. The objective of this report is to aid the transfer of this technology to the private sector.

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

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

    2015-05-01

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

  16. A Speed Control Method for Underwater Vehicle under Hydraulic Flexible Traction

    Yin Zhao; Ying-kai Xia; Ying Chen; Guo-Hua Xu

    2015-01-01

    Underwater vehicle speed control methodology method is the focus of research in this study. Driven by a hydraulic flexible traction system, the underwater vehicle advances steadily on underwater guide rails, simulating an underwater environment for the carried device. Considering the influence of steel rope viscoelasticity and the control system traction structure feature, a mathematical model of the underwater vehicle driven by hydraulic flexible traction system is established. A speed contr...

  17. Control rod driving hydraulic pressure device

    The present invention concerns a control rod driving hydraulic device of a BWR type reactor, and provides an improvement for a means for supplying mechanical seal flashing water of a pump. That is, a mechanical seal flashing pipeline is branched at the downstream of a pressure-reducing orifice and connected to a minimum flow pipeline. With such a constitution, the minimum flow pipeline is connected to a minimum flow pipeline of an auxiliary pump at the downstream of the pressure-reducing orifice and returned to a suction pipeline of the pump. Pressure at the downstream of the pressure-reducing orifice is set, in the orifice, to a pressure required for mechanical seal flashing. Accordingly, the mechanical seal flashing pipeline is connected and a part of minimum flow rate is utilized, thereby enabling to cool mechanical seals. As a result, flow rate of the mechanical flashing water which has been flown out can be saved. The exhaustion amount from the pump can be reduced, to decrease the shaft power and reduce the capacity of the motor. (I.S.)

  18. 14 CFR 33.72 - Hydraulic actuating systems.

    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...

  19. Controlling a negative loaded hydraulic cylinder using pressure feedback

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

    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...

  20. Mathematical Models of Hydraulic Systems, Examples, Analysis

    Straškraba, Ivan

    Praha : ÚT AV ČR, 2006 - (Příhoda, 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 ČR(CZ) GA201/05/0005 Institutional research plan: CEZ:AV0Z10190503 Keywords : hydraulic systems * fluid flow * mathematical models Subject RIV: BA - General Mathematics

  1. Hydraulics in heating systems. Hydraulik in Heizanlagen

    Schlapmann, D. (Buderus Heiztechnik GmbH, Lollar (Germany))

    1993-12-01

    This continuation report describes various possibilities for executing hydraulics in heating systems. The systems described here are: single-boiler system with high-efficiency boiler, multi-boiler system with high-efficiency boilers and Tichelmann connection, serial connection of a high-efficiency boiler with a conventional, dual-fuel boiler for oil and gas, connection of a dual-fuel boiler for oil and gas with an exhaust gas heat exchanger for waste heat utilization, and parallel connection of a dual-fuel boiler for solid fuel and oil with a gas boiler. (BWI)

  2. D2O system and oil hydraulic system of fuelling machine

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

  3. Dynamics of Hydraulic-Fracturing Controlled Microseismicity

    Shapiro, S. A.; Dinske, C.; Rothert, E.

    2006-12-01

    Several dynamic processes related to propagation of hydraulic fracture modify the stress state in rocks and, therefore, they are relevant for triggering of microseismicity. For instance, these are the creation of a new fracture volume, fracturing fluid loss and its infiltration into reservoir rocks as well as diffusion of the injection pressure into the pore space of surrounding rocks and inside the fracture. Using real data, we show that some of these processes can be seen from features of spatio-temporal distributions of the induced microseismicity. Especially, the initial stage of fracture volume opening as well as the back front of the induced seismicity starting to propagate after termination of the fluid injection can be well identified and used for reservoir engineering. We have observed these signatures in many data sets of hydraulic fracturing in tight gas reservoirs. Evaluation of spatio-temporal dynamics of induced microseismicity can contribute to estimate important physical characteristics of hydraulic fractures, e.g., penetration rate of the hydraulic fracture, its permeability as well as the permeability of the reservoir rock. The quality of location of microseismicity is of tremendous importance for such applications. Understanding of fluid-induced seismicity by hydraulic fracturing in boreholes can help us to understand natural fracture processes related to dehydration and degassing phenomena by subduction and faulting.

  4. Analysis of and H∞ Controller Design For An Electro-Hydraulic Servo Pressure Regulator

    Stubkier, Søren; Pedersen, Henrik C.; Andersen, Torben Ole; Madsen, Andreas; Dahl, Mads

    -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...

  5. Simulation of dynamics of system with hydraulic lines and linear hydraulic motor with mass load

    Vašina M.; Hružík L.; Bureček 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. © Owne...

  6. Rubber seals for fluid and hydraulic systems

    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

  7. Hydraulic Characteristics of the Maria Reactor Control Rod Seat

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

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

    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

  9. Hydraulic power take-off for wave energy systems

    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...

  10. Proceedings of transient thermal-hydraulics and coupled vessel and piping system responses 1991

    This book reports on transient thermal-hydraulics and coupled vessel and piping system responses. Topics covered include: nuclear power plant containment designs; analysis of control rods; gate closure of hydraulic turbines; and shock wave solutions for steam water mixtures in piping systems

  11. INFORMATION-MEASURING TEST SYSTEM OF DIESEL LOCOMOTIVE HYDRAULIC TRANSMISSIONS

    I. V. Zhukovytskyy; I. A. Kliushnyk; O.B.Ochkasov; R. O. Koreniyk

    2015-01-01

    Purpose. The article describes the process of developing the information-measuring test system of diesel locomotives hydraulic transmission, which gives the possibility to obtain baseline data to conduct further studies for the determination of the technical condition of diesel locomotives hydraulic transmission. The improvement of factory technology of post-repair tests of hydraulic transmissions by automating the existing hydraulic transmission test stands according to the specifications of...

  12. Sliding Control with Chattering Elimination for Hydraulic Drives

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

    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 characteri......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...

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

    Sørensen, Rasmus Mørk; Hansen, Michael Rygaard; Mouritsen, Ole Ø.

    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...

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

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

  15. Remote Control of Hydraulic Equipment for Unexploded Ordnance Remediation

    Terwelp, Christopher Rome

    2003-01-01

    Automation of hydraulic earth moving and construction equipment is of prime economic and social importance in todayâ s marketplace. A human operator can be replaced or augmented with a robotic system when the job is too dull, dirty or dangerous. There are a myriad of applications in both Government and Industry that could benefit from augmenting or replacing an operator of hydraulic equipment with an intelligent robotic system. A specific important situation is the removal of unexplode...

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

    Castillo, C.; Pérez, R.; Gómez, J. A.

    2013-09-01

    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.

  17. Providing Cavitation-Free Operation of Hydraulic Systems under Passing Load in Hydraulic Actuator

    Liliya Salimovna Musina; Dmitry Vladimirovich Tselischev; Vladimir Aleksandrovich Tselischev; Sergey Yurievich Konstantinov; Ramil Salimovich Musalimov

    2014-01-01

    The problems of braking and positioning of hydraulic actuators are an integral part of output speed control in hydro-pneumatic actuators. This article is focused on a hydraulic braking of driven elements of machines and mechanisms which is carried out by devices known as brake valves (counterbalance, load control, over-centre valves). Brake valves are used to exclude overrunning speed under passing loads when the external load direction coincides with the direction of movement (rotation) of t...

  18. A Hydraulic Transfer System for Producing Radioisotopes

    Jeong, Joonho; Lee, Sangjin; Lee, Chungyoung; Lee, Jongmin [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    Research reactors are constructed mainly for producing radioisotopes, neutron beams and neutron irradiation research and so on. The research reactors generally have two separate area; one is the reactor area and the other is the radioisotopes (RI) production area. After various irradiation objects are irradiated in the reactor located in the reactor area, they are transferred to the RI production building for post-processing. The Hydraulic Transfer System (HTS) is one of RI production and utilization facilities of a research reactor. The HTS is for irradiating targets in the reactor core, and targets are transferred through pipes by hydraulic force. A similar system can be seen in other research reactor such as FRM II, JMTR, HFIR, etc. There are two parallel open-loops used to irradiate targets, and the HTS will circulate pool water to load/unload targets into/from the irradiation tubes and cool targets during irradiation. This paper contains the introduction and operation of the HTS. The HTS permits instantaneous irradiation activity during the reactor operation. It contributes to the RI production and utilization for public welfare, industrial applications and research areas.

  19. Automated testing systems with hydraulic force excitation /review/

    Tiablikov, Iu. E.; Levin, O. A.

    1983-01-01

    Test equipment with hydraulic force excitation is discussed. Various aspects of such devices are discussed, including servovalves, electric restrictive amplifiers, recuperative exciters, resonant amplification of excited loads and strains within the specimen, hybrid force excitation systems, dual-frequency MDU type machines, and dynamic loading devices. Also examined are the development of special sources of hydraulic energy, of more efficient oil filters, and of equipment for full-size tests on structures in the conditions simulating service loading. The functioning of new heavy-load test machines is described, giving examples. The use of digital computers for controlling the many functions of such devices is discussed, as is automation of the testing process. Finally, efforts to make these systems simpler and more economical are addressed.

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

    Pedersen, Henrik Clemmensen

    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...

  1. Application of characteristic time concepts for hydraulic fracture configuration design, control, and optimization. Final report

    Advani, S.H.; Lee, T.S. [Lehigh Univ., Bethlehem, PA (United States); Moon, H. [Ohio State Univ., Columbus, OH (United States)

    1992-10-01

    The analysis of pertinent energy components or affiliated characteristic times for hydraulic stimulation processes serves as an effective tool for fracture configuration designs optimization, and control. This evaluation, in conjunction with parametric sensitivity studies, provides a rational base for quantifying dominant process mechanisms and the roles of specified reservoir properties relative to controllable hydraulic fracture variables for a wide spectrum of treatment scenarios. Results are detailed for the following multi-task effort: (a) Application of characteristic time concept and parametric sensitivity studies for specialized fracture geometries (rectangular, penny-shaped, elliptical) and three-layered elliptic crack models (in situ stress, elastic moduli, and fracture toughness contrasts). (b) Incorporation of leak-off effects for models investigated in (a). (c) Simulation of generalized hydraulic fracture models and investigation of the role of controllable vaxiables and uncontrollable system properties. (d) Development of guidelines for hydraulic fracture design and optimization.

  2. Application of characteristic time concepts for hydraulic fracture configuration design, control, and optimization

    Advani, S.H.; Lee, T.S. (Lehigh Univ., Bethlehem, PA (United States)); Moon, H. (Ohio State Univ., Columbus, OH (United States))

    1992-10-01

    The analysis of pertinent energy components or affiliated characteristic times for hydraulic stimulation processes serves as an effective tool for fracture configuration designs optimization, and control. This evaluation, in conjunction with parametric sensitivity studies, provides a rational base for quantifying dominant process mechanisms and the roles of specified reservoir properties relative to controllable hydraulic fracture variables for a wide spectrum of treatment scenarios. Results are detailed for the following multi-task effort: (a) Application of characteristic time concept and parametric sensitivity studies for specialized fracture geometries (rectangular, penny-shaped, elliptical) and three-layered elliptic crack models (in situ stress, elastic moduli, and fracture toughness contrasts). (b) Incorporation of leak-off effects for models investigated in (a). (c) Simulation of generalized hydraulic fracture models and investigation of the role of controllable vaxiables and uncontrollable system properties. (d) Development of guidelines for hydraulic fracture design and optimization.

  3. Shock analysis on hydraulic drive control rod during scram

    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)

  4. MONITORING INTENSE THE DEFORMED CONDITION HYDRAULIC ENGINEERING CONSTRUCTIONS MELIORATIVE SYSTEMS ?????????? ??????????-???????????????? ????????? ???????????????? ?????????? ????????????? ??????

    Volosoukhin V. A.

    2012-04-01

    Full Text Available Results of operational monitoring are given is long maintained GTS of meliorative systems with nondestructive control methods. Possibility of use of devices of nondestructive control is especially noted at inspection of hydraulic engineering constructions, on an example of water carrying out channels that allows operatively, without additional damages, to receive an objective assessment of their technical condition. When using this approach, there is a possibility justification of parameters of defects and damages, which is impossible to establish at visual survey. The program complex for modeling of a technical condition of holding channels for calculation of predicted term of their service is also presented

  5. Solid Waste Operations Complex (SWOC) Facilities Sprinkler System Hydraulic Calculations

    The attached calculations demonstrate sprinkler system operational water requirements as determined by hydraulic analysis. Hydraulic calculations for the waste storage buildings of the Central Waste Complex (CWC), T Plant, and Waste Receiving and Packaging (WRAP) facility are based upon flow testing performed by Fire Protection Engineers from the Hanford Fire Marshal's office. The calculations received peer review and approval prior to release. The hydraulic analysis program HASS Computer Program' (under license number 1609051210) is used to perform all analyses contained in this document. Hydraulic calculations demonstrate sprinkler system operability based upon each individual system design and available water supply under the most restrictive conditions

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

    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. System for Continuous Deaeration of Hydraulic Oil

    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.

  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

    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.

  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

    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. Design of Pumps for Water Hydraulic Systems

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

    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....

  11. Design of Pumps for Water Hydraulic Systems

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

    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...

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

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

    2010-12-01

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

  13. Hydraulically actuated hexapod robots design, implementation and control

    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...

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

    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.

  15. Acceptance Test Report for 241-SY Pump Cradle Hydraulic System

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

  16. Boosted PWM open loop control of hydraulic proportional valves

    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

  17. Boosted PWM open loop control of hydraulic proportional valves

    Amirante, R.; Catalano, L.A. [Dipartimento di Ingegneria Meccanica e Gestionale, Politecnico di Bari, Via Re David 200, 70125 Bari (Italy); Innone, A. [Universita degli Studi di Foggia, via Napoli, 25 Foggia (Italy)

    2008-08-15

    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. (author)

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

    Soerum, Anders

    2006-03-15

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

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

    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.

  20. Method and apparatus for controlling hydraulic vehicle transmission

    Stark, R.A.

    1987-08-04

    This patent describes an improved hydraulic control means for a vehicle transmission including a speed clutch and direction clutches, a hydraulic fluid reservoir, a hydraulic pump connected to the reservoir, a pressure regulator connected to the pump, and manually operable selector valve means connected to the regulator and with the direction clutches for directing hydraulic fluid to the speed clutch and direction clutches in accordance with the direction and speed desired for the vehicle. The improvement comprises: sequence valve means connected to the selector valve means and connected with the clutches, the sequence valve means including a shuttle valve receiving hydraulic fluid from the selector valve means and a spool valve connected with the shuttle valve with the reservoir. With the speed clutch, the shuttle valve connects between the spool valve and direction clutches. The spool valve dumps pressure fluid from the speed clutch into the reservoir for inactivating the speed clutch when in a bleed position and supplies pressure fluid to the speed clutch for actuating the speed clutch when moved to a pressure position; and, the spool valve is moved into the pressure position by pressure fluid in the shuttle valve after one direction clutch is activated and biased into the bleed position by a resilient member.

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

    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...

  2. Hydraulic control of an automatic transmission

    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.

  3. The research on control rod insertion of a boiling water reactor with water hydraulic drive

    This thesis reports on the hydraulic driving system, powered by an accumulator. This drive system is mainly used for the drive of control rods of nuclear reactors. In case of strong earthquakes, control rods are set in gaps between fuel assemblies to scram nuclear reactors. Characteristics of the system have not been analyzed. The analysis of this system is necessary in order to present the designs that are intended to be a variety of situations. So we developed the model of the hydraulic control rod driving system. The model that we have created is able to reproduce the actual driving. Also, there is a load on the system by an earthquake. This load is caused by the contact of the deformed fuel assembly and control rod. This load model is obtained by solving the equation of motion of the beam. (author)

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

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

    2014-03-01

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

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

    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...

  6. Geosiphon(TM) Ground Water Remediation System Hydraulics

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

  7. Design of a Hydraulic Motor System Driven by Compressed Air

    Jyun-Jhe Yu

    2013-06-01

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

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

    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

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

    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...

  10. State of the art-hydraulic yaw systems for wind turbines

    Stubkier, Søren; Pedersen, Henrik C.; Andersen, Torben Ole; Markussen, Kristian

    2011-01-01

    This paper addresses the yawing systems of Horizontal Axis Wind Turbines (HAWT’s). HAWT’s represents close to all of the commercial large wind turbines sold today and must be considered state-of-the art within wind turbine technology. Two choices exists when considering components for the active...... mounted with a reduction gear. This paper presents state-of-the art within; hydraulic yaw system design and control of yaw systems in general. Primary focus on the advantages and disadvantages of using a hydraulic system for controlling the yaw of a wind turbine with a soft yaw concept....

  11. Model Based Control of a Multi-Axis Hydraulic Shaker Using experimental Modal analysis

    De Bruyne, Stijn; Santos, Fabio; Peeters, Bart; Anthonis, Jan; Appolloni, Matteo; Cozzani, Alessandro

    2012-07-01

    This paper describes the development of a decoupling vibration control system for a multi-axis hydraulic shaker facility. The control system is based on the Internal Model Control (IMC) architecture. While an accurate model of the hydraulic subsystem should only be identified once, there is a strong need for a systematic procedure for identifying the mechanical subsystem. Based on the PolyMAX identification method, an accurate mechanical model can be obtained through experimental modal analysis. The procedure and results of an experimental measurement campaign are reported. In a simulation analysis, the resulting PolyMAX-IMC control system has proven to achieve an improved performance regarding reference tracking, limited time harmonic distortion and cross-talk reduction.

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

    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 st...... 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.......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...

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

    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.

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

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

  15. European developments in thermal-hydraulics for innovative nuclear systems

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

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

    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

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

    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.

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

    Tri-Vien Vu

    2014-10-01

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

  19. Hydraulic Soft Yaw System Load Reduction and Prototype Results

    Stubkier, Søren; Pedersen, Henrik C.; Markussen, Kristian

    2013-01-01

    Introducing a hydraulic soft yaw concept for wind turbines leads to significant load reductions in the wind turbine structure. The soft yaw system operates as a shock absorption system on a car, hence absorbing the loading from turbulent wind conditions instead of leading them into the stiff wind...... turbine structure. Results presented shows fatigue reductions of up to 40% and ultimate load reduction of up to 19%. The ultimate load reduction increases even more when the over load protection system in the hydraulic soft yaw system is introduced and results show how the exact extreme load cut off...... operates. Further it is analyzed how the soft yaw system influence the power production of the turbine. It is shown that the influence is minimal, but at larger yaw errors the effect is possitive. Due to the implemeted functions in the hydraulic soft yaw system such as even load distribution on the pinions...

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

    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

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

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

    2002-03-01

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

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

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

    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...... 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...

  3. A comparison of hydraulic, pneumatic, and electro-mechanical actuators for general aviation flight controls

    Roskam, J.; Rice, M.; Eysink, H.

    1979-01-01

    Mathematical models for electromechanical (EM), pneumatic and hydraulic actuations are discussed. It is shown that EM and hydraulic actuators provide better and faster time responses than pneumatic actuators but EM actuators utilizing the recently developed samarium-cobalt technology have significant advantages in terms of size, weight and power requirements. In terms of ease and flexibility of installation EM actuators apparently have several advantages over hydraulic actuators, and cost is a primary reason for the popularity of EM actuation for secondary control function since no additional systems need to be added to the aircraft. While new rare earth magnets are currently in developmental stage, costs are relatively high; but continued research should bring prices down.

  4. Hydraulic External Pre-Isolator System for LIGO

    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.

  5. Hydraulic external pre-isolator system for LIGO

    The hydraulic external pre-isolator (HEPI) is the first six degrees of freedom active seismic isolation system implemented at the Laser Interferometer Gravitational Wave Observatory (LIGO). Implementation was first completed at the LIGO Livingston Observatory (LLO) prior to LIGO's fifth science run7, successfully cutting down the disturbance seen by LLO's suspended optics in the two most prominent seismic disturbance bands, the microseism (0.1–0.3 Hz) and the anthropogenic (1–3 Hz) bands, by a factor of a few to tens. The improvement in seismic isolation contributed directly to LLO's much improved duty cycle of 66.7% and LIGO's triple coincident duty cycle of 53%. We report the design, control scheme, and isolation performance of HEPI at LLO in this paper. Aided by this success, funding for incorporating HEPI into the LIGO Hanford Observatory was approved and installation is currently underway. (paper)

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

    Zoran Đukan Majkić

    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, especially when going around a curve. In order to achieve this, a reactive element is built into the hydraulic servo control, with a task to absorb rapidly drive wheel oscillations during the reverse inclusion of the hydraulic servo control (from the drive wheels to the steering wheel. Determination of the dimensions of reactive elements and the stiffness of centering springs Taking the results of the static analysis into account, the dependence of force and the torsional resistance in drive wheels can be obtained. From this dependence, P can be found  as a function of . Control calculation The control calculation is performed after selecting general elements of the control system and the amplifier.The control  calculation allows the reduction of amplifier dimensions through the transmission gear mechanism, by selecting the   part onto which amplifier force.is applied. Conclusion The calculation of the control system helps in determining the basic parameters of its elements and assemblies, thus providing the control over the vehicle motion. The main input data in calculating hydraulic servo control is the determination of torsional resistance in drive wheels. In order to achieve proper torque values in torsional resistance, it is necessary to take into account  the given influencing factors since this ensures, on the one hand, lower load on the control system elements and, on the other hand, easier control by reducing the force applied to the steering wheel. ECE Regulation № 79 defines the maximum force that can be applied to the steering wheel, so this paremeter of control systems must be taken into account in vehicle design. The piston stroke and the cylinder length are determined for maximum torque angles of drive wheels, followed vy the determination of the cylinder piston diameter. The tendency to reverse the action of the  hydraulic servo control would violate the basic requirement to the control system which is to get drive wheels back into straight line motion under the influence of the stabilizing moment. In order to prevent reverse action, a reactive and centering element is installed into the hydraulic servo control.Prestressing of central springs provides the return of the steering and drive wheels under the influence of the stabilizing moment without involving the hydraulic servo control. Friction force in the control mechanism must be lower than the force of prestressed central springs . The control computation is performed after the determination of all parameters in order to test the operating ability of the hydraulic servo control and to obtain its characteristics. A properly designed hydraulic servo control has to provide that the summary execution of torque hydraulic servo control and the driver exceeds the moment of resistance throughout the range of angles of rotation of wheels.

  7. Primary system thermal hydraulics of future FBRS

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

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

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

  9. Analysis on step action of hydraulic control rod driving

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

  10. Development of a thermal-hydraulic system code for simulators based on RELAP5 code

    A thermal-hydraulic system code for simulators, RELAPSIM, was developed at NSSE based on RELAP5. The development procedure consists of three major parts. Firstly, time control function was added into the code to meet real-time calculation needs. Secondly, controlled dynamic data communication was improved, so that thermal-hydraulic parameters can be easily modified for further applications. Finally, functions controlling the computation procedure were embedded to achieve a full capability to simulate multiple operations, such as start-up, shutting down or freeze. This paper describes the main features of the new code. The results of code assessment and code application are presented and discussed

  11. Thermal hydraulic instrumentation system of the HTR-10

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

  12. 46 CFR 128.240 - Hydraulic or pneumatic power and control-materials and pressure design.

    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...

  13. Application of Fuzzy Clustering in Modeling of a Water Hydraulics System

    Zhou, Jianjun; Kroszynski, Uri

    This article presents a case study of applying fuzzy modeling techniques for a water hydraulics system. The obtained model is intended to provide a basis for model-based control of the system. Fuzzy clustering is used for classifying measured input-output data points into partitions. The fuzzy...

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

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

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

    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.

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

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

    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 nonli...

  17. Neutron kinetics for system thermal-hydraulic codes

    For many light water reactor (LWR) calculations, it is necessary to use a multidimensional neutron kinetics model coupled to a thermal-hydraulic model in order to obtain satisfactory results. This need coincides with the fact that in recent years there has been considerable research and development in this field with modelers taking advantage of the increase in computing power that has become available. This progress has now led to coupling the core neutron kinetics and thermal-hydraulics calculation to the nuclear steam supply system thermal-hydraulics. This can now be done with very sophisticated models, and the planning of this coupling and the requisite modeling can take advantage of the experience of many code developers in many countries. This paper us one contribution to the planning process for the next generation of system thermal-hydraulic codes. The paper presents the author', conclusions as to what neutron kinetics model and solution algorithms might be implemented, how to initialize the problem, what thermal-hydraulic boundary conditions are needed by the neutron kinetics, and the modeling for cross sections, power generation, and boron transport. In order to justify recommendations, LWR applications are discussed. 3 refs., 2 tabs

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

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

    2010-01-01

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

  19. Research on One Borehole Hydraulic Coal Mining System

    XIA, Bairu; ZENG, Xiping; MAO, Zhixin

    The Borehole Hydraulic Coal Mining System (BHCMS) causes fragmentation of coal seams and removes coal slump through a drilled hole using high-pressure water jet. Then the mixture of coal and water as slurry are driven out of the borehole by hydraulic or air-lifting method, and are separated at the surface. This paper presents a case study of hydraulic borehole coal mining. The three key techniques of the BHCMS, namely, hydraulic lift of jet pump, air lift, and water jet disintegration are discussed and analyzed in this paper based on theoretical analysis and field experiments. Some useful findings have been obtained: (1) The design of jet pump, air lift system, and water jet has to be integrated appropriately in order to improve mining efficiency and coal recovery rate, and to decrease energy consumption. The design of hydraulic lift jet pump must meet the requirement of the minimum floating speed of coal particles. The optimization of nondimensional parameters and prevention of cavitation have to be considered in the design; (2) With regard to selecting the nozzle types of jet pump, center nozzle or annular nozzle can be selected according to the size of the removed particles; (3) Through air-lift and back pressure, the water head can be decreased to improve the lift capacity of jet pump and decrease the power loss. The air lift has great limitation if it is used solely to extract coal, but if it is employed in conjunction with jet pump, the lift capacity of jet pump can be increased greatly; (4) With water jets, the air lift can improve the fragmentation radius and capacity. The main factors that affect the effect of water jet are the submergible status of jet, jet pressure, and flowrate. The ideal jet of the monitor in the borehole hydraulic coal-mining system is a nonsubmergible free jet. Through air lift, the nonsubmergible free jet can be set up in the mining hole.

  20. Modeling, Identification and Control Design for an Electro-Hydraulic Rotator

    Zanhar, Andrej

    2010-01-01

    Robotic manipulators have been introduced in industry as a form of increasing productivity. Today, there exist an interest to enlarge the application of these manipulators to outdoor environments. Forestry cranes used in the forestry industry are a clear example. A long term goal in this industry is the development of autonomous systems to increase the logging efficiency. In this thesis, we consider how to control the rotator of these cranes, which is an electro-hydraulically actuated motor, ...

  1. Optimization of maintenance of turbine electro hydraulic control (EHC)

    With traditional preventive maintenance, each component of the hydraulic part of the EHC system is checked about every five years. However, with this philosophy, components not checked during shutdown are not guaranteed to function correctly. Maintenance costs are also higher, as part are checked whether they require it or not. availability and reliability of the EHC systems can be improved, and costs cut, as follows - Condition-based checking of critical components whose maintenance cost is high (mainly actuators, pumps and storage batteries). - applying preventive maintenance in zones that act as external barrier (replace gaskets) -Ensuring that maintenance is done correctly and that components function correctly at startup. Correct functioning of components and determination of their condition is based on system diagnosis: leaks prior to shutdown, functioning immediately after shutdown, and a post-maintenance test before start-up (Author)

  2. Test Rig Design and Presentation for a Hydraulic Yaw System

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

    The design and development of a hydraulic yaw system for multi MWturbines is presented and the concept explained. As part of the development of the new concept a full scale test rig for a 5 MW wind turbine has been designed and constructed. The test rig is presented along with its unique design...

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

    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.

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

    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.

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

    Teodor Eugen Man

    2010-01-01

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

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

    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 - Timisoara Branch, Laboratory for Hydrodynamics and Cavitation, led to complex projects that combine both basic theoretical developments with advanced experimental investigations leading to practical engineering solutions for modern hydraulic machines. The International Association of Hydro-Environment Engineering and Research (IAHR) celebrates its 75th anniversary this year. 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, 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 at large. Hydraulic machinery is both cost effective and environmentally responsible. The increasing atmospheric content of carbon dioxide related to pollution from thermal power plants, is one of the most significant threats to our global ecology. The problem is exacerbated by the need for increased energy production in third world countries. This results in rising global temperatures and dramatic changes in climate which may also result in flooding in parts of our globe. Energy conservation together with replacement of coal and oil-fired power plants are, therefore, needed. The development and installation of more efficient hydroelectric power plants which work hand in hand with water storage and flood protection is part of this strategy. Waterpower is the most significant 'renewable resource'. The goals of this IAHR - Committee on Hydraulic Machinery and Systems are to improve the value of hydraulic machinery to the end user and to society and to improve society's understanding and appreciation of that value. The series of IAHR Symposia on Hydraulic Machinery and Cavitation started with the 1st edition in Nice in 1960 in France. Within the past decade, all the symposia were focused on an extended portfolio of topics under the name of 'Hydraulic Machinery and Systems', such as the 20th edition in 2000, Charlotte, USA, the 21st in 2002, Lausanne, Switzerland, the 22nd in 2004, Stockholm, Sweden, the 23rd in 2006, Yokohama, Japan, and the 24th in 2008, Foz do Iguassu, Brasil. The 25th IAHR Symposium on Hydraulic Machinery and Systems brings together more than 150 scientists and researchers from 24 countries, affiliated with universities , technology centres and industry to debate topics related to advanced technologies for hydraulic machinery and systems, which will enhance the sustainable development of water resources and hydropower production. The Scientific Committee has selected 118 papers, out of 238 abstracts submitted, on the following topics: (i) Hydraulic Turbines and Pumps, (ii) Sustainable hydropower, (iii) Hydraulic Systems, (iv) Advances in Computational and Experimental Techniques, (v) Innovative Technology, to be presented at the symposium and to be included in the proceedings. All papers published in this Volume 12 of IOP Conference Series: Earth and Environmental Science have been peer reviewed through processes administered by the editors of the 25th IAHR Symposium on Hydraulic Machinery and Systems proceedings, Professor Romeo Susan-Resiga, Dr Sebastian Muntean and Dr Sandor Bernad. We hope that this anniversary edition of the series of symposia on Hydraulic Machinery and Systems will be a significant step forward in the worldwide efforts to address the present challenges facing the modern hydraulic machines. Professor Romeo Susan-Resiga Chairman of the Organizing Committee 25th IAHR Symposium on Hydraulic Machinery and Systems

  7. Process instrumentation system for sodium thermo-hydraulic experimental loop

    The process instrumentation system for liquid sodium thermo-hydraulic experiment provides appropriate methods of measurement and indication. It can be used to inspect main process parameters (temperature, pressure, flow, liquid level, power etc.) and the state of equipment. Function of the system is normal, inspection of instrument is exact and reliable, regulation is sensitive, operation is simple and convenient after installation and adjustment of this system. The result demonstrates an expected purpose of design

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

    Zhao Zhen Lu; Chen Rong Fan; Chu Cheng Jie

    2002-01-01

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

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

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

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

    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. Non Linear Modelling and Control of Hydraulic Actuators

    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.

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

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

    2009-07-01

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

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

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

    1988-01-01

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

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

    Tahavori, Maryamsadat; Leth, John-Josef; Kallesøe, 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 consump...... control problem is the interior point method. The method which is used in this paper can be used for a general hydraulic networks to optimize the leakage and energy consumption and to satisfy the demands at the end-users.......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 and it is considered to be a disturbance. The method which is used to solve the nonlinear optimal...

  15. The Newest Hydraulic Engineering

    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.

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

    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)

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

    A. G. Sotnikov

    2011-03-01

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

  18. Hydraulic Fracturing for Enhanced Geothermal Systems

    Rongved, Mats

    2015-01-01

    Finding new energy sources to provide base load electricity supply on a global scale is of increasing importance. Enhanced Geothermal Systems (EGS) has been identified as capable of playing an important role in the future of the energy market. The normally overlooked energy source has a great resource base, but faces challenges in order to become a serious energy alternative on a global scale. The main focus of this thesis is to investigate the properties demanded of effective fracture netwo...

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

    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. PMID:26520981

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

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

  1. Hydraulic Soft Yaw System for Multi MW Wind Turbines

    Stubkier, Søren

    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......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...

  2. Thermal-hydraulic tests for reactor safety system

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

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

    Borland, Mark Wilson; Berry, Stephen Michael

    1999-04-01

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

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

    M. Borland; S. M. Berry

    1999-04-01

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

  5. Pneumatic and Hydraulic Systems in Coal Fluidized Bed Combustor

    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...

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

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

    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....

  7. Hydraulic tests of emergency cooling system: L-Area

    Hinton, J H

    1988-01-01

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

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

    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)

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

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

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

    Schmidt, Lasse

    expensive process, making it difficult to comply with tight budgets and delivery deadlines. The objective of this project is to overcome these issues, and develop controls aiming at robustness, consistent performance, simple parameter design and applicability under industrial conditions, i.e. with only...... are widely used. Such controllers typically provide the possibility to employ traditional linear controls such as PID schemes, and variants of this, with parameters tunable via graphical user interfaces. However, due to the intrinsic nonlinearities of hydraulic systems as well as the often limited...... pressure- piston- and spool position sensors, standard proportional valves- and control electronic hardware. The project is limited to consider only position control systems. To achieve the project objective, the possibility of online tracking of system parameters has been investigated, targeting...

  11. Design and performance enhancement of hydraulic pressure energy harvesting systems

    Skow, Ellen A.; Cunefare, Kenneth A.; Erturk, Alper

    2013-04-01

    Hydraulic pressure ripple energy harvesters generate low-power electricity from off-resonance dynamic pressure excitation of piezoelectric elements. Improvements were made to hydraulic pressure ripple energy harvester prototype performance. Hydraulic systems inherently have a high energy intensity associated with the mean pressure and flow. Accompanying the mean pressure is dynamic pressure ripple, which is caused by the action of pumps and actuators. Pressure ripple is generally a deterministic source with a periodic time-domain behavior conducive to energy harvesting. An energy harvester prototype was designed for generating low-power electricity from pressure ripples. These devices generate low-power electricity from off-resonance dynamic pressure excitation. The power produced per volume of device was increased through decreasing the device size and adding an inductor to the system circuit. The prototype device utilizes a piezoelectric stack with high overall capacitance allowing for inductance matching without using a switching circuit. Initial testing with addition of an inductor produced over 2.1 mW, an increase of 78% as compared to the device without the inductor. Two power output model simulations of a resistive-inductive circuit are analyzed: (1) ideal circuit case and (2) non-ideal circuit case with inductor internal resistance included.

  12. Neutron kinetics for system thermal-hydraulic codes

    There is general agreement that for many light water reactor (LWR) calculations for licensing safety analysis, probabilistic risk assessment, operational support, and training, it is necessary to use a multidimensional neutron kinetics model coupled to a thermal-hydraulics model in order to obtain satisfactory results. This need coincides with the fact that in recent years there has been considerable research and development in this field, with modelers taking advantage of the increase in computing power that has become available. This progress has now led to coupling multidimensional neutron kinetics models to the nuclear steam supply system thermal hydraulics. This is not new since some coupled codes have always been available. What is new is that the coupling can now be done with very sophisticated models, and the planning of this coupling and the requisite modeling can take advantage of the experience of many code developers in many countries. The U.S. Nuclear Regulatory Commission and other organizations are in the process of reviewing the state of the art and making recommendations for future development. This paper summarizes one contribution to this review process: a review of the multidimensional neutron kinetics modeling, and ancillary modeling, which would be used in conjunction with system thermal-hydraulic models to perform core dynamics calculations

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

    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

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

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

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

    Jensen, Tom Nørgaard; Wisniewski, Rafal

    2014-01-01

    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......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......-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...

  16. Study on Dynamical Simulation of Railway Vehicle Bogie Parameters Test-bench Electro-hydraulic Servo System

    Lan, Zhikun; Su, Jian; Xu, Guan; Cao, Xiaoning

    Dynamical mathematical model was established for accurately positioning, fast response and real-time tracing of electro-hydraulic servo control system in railway vehicle bog ie parameters test system with elastic load. The model could precisely control the output of position and force of the hydraulic cylinders. Induction method was proposed in the paper. Dynamical simulation verified the mathematical model by SIMULINK software. Meanwhile the key factors affecting the dynamical characteristics of the system were discussed in detail. Through the simulation results, high precision is obtained in application and the need of real-time control on the railway vehicle bogie parameters test-bench is realized.

  17. Role of system characteristics in evolution of pump hydraulic design

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

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

    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.

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

    Pedersen, Mikkel Melters; Hansen, Michael Rygaard; Ballebye, Morten

    2010-01-01

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

  20. Hydraulic transient analysis in circulating water pump system

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

  1. Optimising root system hydraulic architectures for water uptake

    Meunier, Flicien; Couvreur, Valentin; Draye, Xavier; Javaux, Mathieu

    2015-04-01

    In this study we started from local hydraulic analysis of idealized root systems to develop a mathematical framework necessary for the understanding of global root systems behaviors. The underlying assumption of this study was that the plant is naturally optimised for the water uptake. The root system is thus a pipe network dedicated to the capture and transport of water. The main objective of the present research is to explain the fitness of major types of root architectures to their environment. In a first step, we developed links between local hydraulic properties and macroscopic parameters of (un)branched roots. The outcome of such an approach were functions of apparent conductance of entire root system and uptake distribution along the roots. We compared our development with some allometric scaling laws for the root water uptake: under the same simplifying assumptions we were able to obtain the same results and even to expand them to more physiological cases. Using empirical data of measured root conductance, we were also able to fit extremely well the data-set with this model. In a second stage we used generic architecture parameters and an existent root growth model to generate various types of root systems (from fibrous to tap). We combined both sides (hydraulic and architecture) then to maximize under a volume constraint either apparent conductance of root systems or the soil volume explored by active roots during the plant growth period. This approach has led to the sensitive parameters of the macroscopic parameters (conductance and location of the water uptake) of each single plant selected for this study. Scientific questions such as: "What is the optimal sowing density of a given hydraulic architecture ?" or "Which plant traits can we change to better explore the soil domain ?" can be also addressed with this approach: some potential applications are illustrated. The next (and ultimate phase) will be to validate our conclusions with real architectures data and with a physical model of the water fluxes in the soil-plant continuum.

  2. Hydraulic characterisation of karst systems with man-made tracers

    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)

  3. Hydraulic external pre-isolator system for LIGO

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

    2014-01-01

    The hydraulic external pre-isolator (HEPI) is the first six degrees of freedom active seismic isolation system implemented at the Laser Interferometer Gravitational Wave Observatory (LIGO). Implementation was first completed at the LIGO Livingston Observatory (LLO) prior to LIGOʼs fifth science run, successfully cutting down the disturbance seen by LLOʼs suspended optics in the two most prominent seismic disturbance bands, the microseism (0.1–0.3 Hz) and the anthropogenic (1–3 Hz) bands, by a...

  4. Linear hydraulic drive system for a Stirling engine

    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

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

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

    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...... 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...

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

    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, Poincar 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.

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

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

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

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

  10. Pneumatic and Hydraulic Systems in Coal Fluidized Bed Combustor

    Z. O. Opafunso

    2009-01-01

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

  11. Electromechanical propellant control system actuator

    Myers, W. Neill; Weir, Rae Ann

    1990-01-01

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

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

    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, θ, 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 θ 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 θ 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 θ 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.

  13. Transient Thermal Hydraulic Analyses of Heavy Water System

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

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

    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, 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...

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

    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...... gear pumps, the throttling losses are confined to cross port leakage in the cylinder and leakage of the pumps. However, it turns out that the volumetric pump losses and the pressure dynamics of the cylinder and connecting pipes may cause pressure increase- or decrease in the cylinder chambers, which...... proportional valves, this design allows to control the lower chamber pressure levels, throttling excess compression flow to tank. The resulting design introduces additional losses due to throttling of excess compression flow, but also improves the dynamic properties of the system significantly. The proposed...

  16. Experimental validation of microseismic emissions from a controlled hydraulic fracture in a synthetic layered medium

    Roundtree, Russell

    A controlled hydraulic fracture experiment was performed on two medium sized (11" x 11" x 15") synthetic layered blocks of low permeability, low porosity Lyons sandstone sandwiched between cement. The purpose of the research was to better understand and characterize the fracture evolution as the fracture tip impinged upon the layer boundaries between the well bonded layers. It is also one of the first documented uses of passive microseismic used in a laboratory environment to characterize hydraulic fracturing. A relatively low viscosity fluid of 1000 centipoise, compared to properly scaled previous work (Casas 2005, and Athavale 2007), was pumped at a constant rate of 10 mL/minute through a steel cased hole landed and isolated in the sandstone layer. Efforts were made to contain the hydraulic fracture within the confines of the rock specimen to retain the created hydraulic fracture geometry. Two identical samples and treatment schedules were created and differed only in the monitoring system used to characterize the microseismic activity during the fracture treatment. The first block had eight embedded P-wave transducers placed in the sandstone layer to record the passive microseismic emissions and localize the location and time of the acoustic event. The second block had six compressional wave transducers and twelve shear wave transducers embedded in the sandstone layer of the block. The intention was to record and process the seismic data using conventional P-wave to S-wave difference timing techniques well known in industry. While this goal ultimately not possible due to the geometry of the receiver placements and the limitations of the Vallene acquisition processing software, the data received and the events localized from the 18 transducer test were of much higher numbers and quality than on the eight transducer test. This experiment proved conclusively that passive seismic emission recording can yield positive results in the laboratory. Just as in the field, this provides one of the best far field (away from the well bore) measurements to assess hydraulic fracture behavior. It also provides a calibration tool to extend laboratory results to field scale endeavors. The identification of strong microseismic activity at stress states far below fracture initiation confirms that rocks are critically stressed meta-stable materials and that microseismicity is caused by stress changes, not fractures directly. Advancements are necessary to fully exploit the potential of the microseismic method in laboratory sized samples. Both processing and visualization enhancements are necessary to realize the full benefits of this promising technology in the laboratory environment.

  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

    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. Nonlinear Model Predictive Control of a Hydraulic Forestry Crane

    Kalmari, Jouko

    2015-01-01

    In forestry, the level of mechanization has increased significantly in recent decades. Modern forest harvesters, used widely in the Nordic countries, are capable of efficiently felling, delimbing and bucking trees. There is also interest in mechanizing other silvicultural tasks to increase the productivity and decrease the demand for labor. Increasing the level of automation in forest machines could be the next logical step. Forest machines are usually equipped with some sort of hydraulic ...

  19. From the Kinetic Energy Recovery System to the Thermo-Hydraulic Hybrid Motor Vehicle

    Cristescu, Corneliu; Drumea, Petrin; Guta, Dragos; Dumitrescu, Catalin

    2011-12-01

    The paper presents some theoretical and experimental results obtained by the Hydraulics and Pneumatics Research Institute INOE 2000-IHP with its partners, regarding the creating of one hydraulic system able to recovering the kinetic energy of the motor vehicles, in the braking phases, and use this recovered energy in the starting and accelerating phases. Also, in the article is presented a testing stand, which was especially designed for testing the hydraulic system for recovery the kinetic energy. Through mounting of the kinetic energy recovering hydraulic system, on one motor vehicle, this vehicle became a thermo-hydraulic hybrid vehicle. Therefore, the dynamic behavior was analyzed for the whole hybrid motor vehicle, which includes the energy recovery system. The theoretical and experimental results demonstrate the possible performances of the hybrid vehicle and that the kinetic energy recovery hydraulic systems are good means to increase energy efficiency of the road motor vehicles and to decrease of the fuel consumption.

  20. PERFORMANCE OF AN AERIAL VARIABLE-RATE APPLICATION SYSTEM WITH A HYDRAULICALLY POWERED CHEMICAL PUMP AND SPRAY VALVE

    The performance was evaluated for a variable-rate system that consisted of a SATLOC M3 with AirTrac software with WAAS corrected DGPS (5 Hz position update) and an AutoCal II automatic flow controller. This system was installed on an Air Tractor 402B equipped with an auxiliary hydraulic package tha...

  1. Thermal Hydraulic Analysis on Containment Filtered Venting System

    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

  2. Thermal Hydraulic Analysis on Containment Filtered Venting System

    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.

  3. Design, simulation, and testing of a novel hydraulic power take-off system for the Pelamis wave energy converter

    Henderson, Ross [Ocean Power Delivery Ltd, Edinburgh, Scotland (United Kingdom)

    2006-02-01

    The economic viability of a wave energy converter depends largely on its power take-off system. Active control of the power take-off is necessary to maximise power capture across a range of sea-states and can also improve survivability. The high force, low speed regime of wave energy conversion makes it a suitable application for high-pressure hydraulics. This paper describes the hydraulic power take-off system employed in the Pelamis wave energy converter. The process of the system's development is presented, including simulation and laboratory tests at 1/7th and fullscale. Results of efficiency measurements are also presented. (author)

  4. Scaling in nuclear reactor system thermal-hydraulics

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

  5. Thermal hydraulic test for core cooling system using steam generators

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

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

    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

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

    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 à 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 à 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); Horvatović, 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.

  8. Hydraulic Modeling of Novel Combined Nozzle for Pool Scrubbing System

    The particles are collected in the scrubbing liquid. Knowing that the particle is removed from the gas stream mainly by scrubbing phenomena, the filtration efficiency can be enhanced by enlarging the contact area between the scrubbing water and the gas/particle mixture (e.g. break the bulk of gas flow into fine bubbles) or by enlarging the contact time of them (e. g. increase the water pool depth). In this study, the novel design of the combined nozzle has been developed to minimize the size of the filtration system and to ensure the filtration efficiency over the wide range of operating conditions. The hydraulic simulation has been conducted to investigate the flow behavior inside of the nozzle prior to evaluate the filtering efficiency. The proto-typical combined nozzle has been modeling in CFD and simulated for different conditions. Preliminary CFD simulation is conducted to examine the effects of key features and the flow behaviors inside the combined nozzle

  9. ITHNA.SYS: An Integrated Thermal Hydraulic and Neutronic Analyzer SYStem for NUR research reactor

    Mazidi, S., E-mail: samirmazidi@gmail.com [Division Physique et Applications Nucléaires, Centre de Recherche Nucléaire de Draria (CRND), BP 43 Sebala, Draria, Alger (Algeria); Meftah, B., E-mail: b_meftah@yahoo.com [Division Physique et Applications Nucléaires, Centre de Recherche Nucléaire de Draria (CRND), BP 43 Sebala, Draria, Alger (Algeria); Belgaid, M., E-mail: belgaidm@yahoo.com [Faculté de Physique, Université Houari Boumediene, USTHB, BP 31, Bab Ezzouar, Alger (Algeria); Letaim, F., E-mail: fletaim@yahoo.fr [Faculté des Sciences et Technologies, Université d’El-oued, PO Box 789, El-oued (Algeria); Halilou, A., E-mail: hal_rane@yahoo.fr [Division Réacteur NUR, Centre de Recherche Nucléaire de Draria, BP 43 Sebala, Draria, Alger (Algeria)

    2015-08-15

    Highlights: • We develop a neutronic and thermal hydraulic MTR reactor analyzer. • The analyzer allows a rapid determination of the reactor core parameters. • Some NUR reactor parameters have been analyzed. - Abstract: This paper introduces the Integrated Thermal Hydraulic and Neutronic Analyzer SYStem (ITHNA.SYS) that has been developed for the Algerian research reactor NUR. It is used both as an operating aid tool and as a core physics engineering analysis tool. The system embeds three modules of the MTR-PC software package developed by INVAP SE: the cell calculation code WIMSD, the core calculation code CITVAP and the program TERMIC for thermal hydraulic analysis of a material testing reactor (MTR) core in forced convection. ITHNA.SYS operates both in on-line and off-line modes. In the on-line mode, the system is linked, via the computer parallel port, to the data acquisition console of the reactor control room and allows a real time monitoring of major physical and safety parameters of the NUR core. PC-based ITHNA.SYS provides a viable and convenient way of using an accumulated and often complex reactor physics stock of knowledge and frees the user from the intricacy of adequate reactor core modeling. This guaranties an accurate, though rapid, determination of a variety of neutronic and thermal hydraulic parameters of importance for the operation and safety analysis of the NUR research reactor. Instead of the several hours usually required, the processing time for the determination of such parameters is now reduced to few seconds. Validation of the system was performed with respect to experimental measurements and to calculations using reference codes. ITHNA.SYS can be easily adapted to accommodate other kinds of MTR reactors.

  10. ITHNA.SYS: An Integrated Thermal Hydraulic and Neutronic Analyzer SYStem for NUR research reactor

    Highlights: • We develop a neutronic and thermal hydraulic MTR reactor analyzer. • The analyzer allows a rapid determination of the reactor core parameters. • Some NUR reactor parameters have been analyzed. - Abstract: This paper introduces the Integrated Thermal Hydraulic and Neutronic Analyzer SYStem (ITHNA.SYS) that has been developed for the Algerian research reactor NUR. It is used both as an operating aid tool and as a core physics engineering analysis tool. The system embeds three modules of the MTR-PC software package developed by INVAP SE: the cell calculation code WIMSD, the core calculation code CITVAP and the program TERMIC for thermal hydraulic analysis of a material testing reactor (MTR) core in forced convection. ITHNA.SYS operates both in on-line and off-line modes. In the on-line mode, the system is linked, via the computer parallel port, to the data acquisition console of the reactor control room and allows a real time monitoring of major physical and safety parameters of the NUR core. PC-based ITHNA.SYS provides a viable and convenient way of using an accumulated and often complex reactor physics stock of knowledge and frees the user from the intricacy of adequate reactor core modeling. This guaranties an accurate, though rapid, determination of a variety of neutronic and thermal hydraulic parameters of importance for the operation and safety analysis of the NUR research reactor. Instead of the several hours usually required, the processing time for the determination of such parameters is now reduced to few seconds. Validation of the system was performed with respect to experimental measurements and to calculations using reference codes. ITHNA.SYS can be easily adapted to accommodate other kinds of MTR reactors

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

    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.

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

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

    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...

  13. Tap Water Hydraulic Systems for Medium Power Applications

    Conrad, Finn; Adelstorp, Anders

    1998-01-01

    Presentation of new range of developed tap water hydraulic componets and applications for medium power up to 4 kW and 50 bar.......Presentation of new range of developed tap water hydraulic componets and applications for medium power up to 4 kW and 50 bar....

  14. Hydraulic Systems with Tap Water versus Bio-oils

    Conrad, Finn

    Deals with the advantages of using pure tap water hydraulics versus bio-oils for suiteable applications. Focus is in particular on food processing industry.......Deals with the advantages of using pure tap water hydraulics versus bio-oils for suiteable applications. Focus is in particular on food processing industry....

  15. COBRA-SFS, Thermal Hydraulics of Spent Fuel Storage System

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

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

    Choux, Martin; Blanke, Mogens

    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, tw...

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

    Choux, Martin; Blanke, Mogens

    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...

  18. 49 CFR 570.57 - Air brake system and air-over-hydraulic brake subsystem.

    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...

  19. Hydraulic-fracturing controlled dynamics of microseismic clouds

    Shapiro, S. A.; Dinske, C.; Rothert, E.

    2006-07-01

    Several dynamic processes related to propagation of hydraulic fracture modify the stress state in rocks and, therefore, they are relevant for triggering of microseismicity. For instance, these are the creation of a new fracture volume, fracturing fluid loss and its infiltration into reservoir rocks as well as diffusion of the injection pressure into the pore space of surrounding rocks and inside the fracture. Using real data, we show that some of these processes can be seen from features of spatio-temporal distributions of the induced microseismicity. Especially, the initial stage of fracture volume opening as well as the back front of the induced seismicity starting to propagate after termination of the fluid injection can be well identified and used for reservoir engineering.

  20. Hydraulic manipulator research at ORNL

    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

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

    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.

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

    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

  3. Development of an Advanced Hydraulic Fracture Mapping System

    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.

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

    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.

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

    L. Batet

    2007-11-01

    Full Text Available Thermal-hydraulic analysis tasks aimed at supporting plant operation and control of nuclear power plants are an important issue for the Asociación Nuclear Ascó-Vandellòs (ANAV. ANAV is the consortium that runs the Ascó power plants (2 units and the Vandellòs-II power plant. The reactors are Westinghouse-design, 3-loop PWRs with an approximate electrical power of 1000 MW. The Technical University of Catalonia (UPC thermal-hydraulic analysis team has jointly worked together with ANAV engineers at different levels in the analysis and improvement of these reactors. This article is an illustration of the usefulness of computational analysis for operational support. The contents presented were operational between 1985 and 2001 and subsequently changed slightly following various organizational adjustments. The paper has two different parts. In the first part, it describes the specific aspects of thermal-hydraulic analysis tasks related to operation and control and, in the second part, it briefly presents the results of three examples of analyses that were performed. All the presented examples are related to actual situations in which the scenarios were studied by analysts using thermal-hydraulic codes and prepared nodalizations. The paper also includes a qualitative evaluation of the benefits obtained by ANAV through thermal-hydraulic analyses aimed at supporting operation and plant control.

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

    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 second order sliding controller based on the so-called prescribed convergence algorithm, when used for...... chattering elimination in hydraulic drive control applications. For this usage the algorithm suffers from poor convergence properties unless a high control gain is chosen, which in turn increases pressure oscillations. To negotiate the combined challenge the controller is extended with a proportional term...

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

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

    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...

  8. A PC code system for calculation of pressure drop in complex hydraulic systems

    A program complex for calculation of friction factors for straight tubes and channels, hydraulic resistance factors for shaped parts of pipelines, barries, throttles, etc., as well as pressure drop during steam-water flow through a local resistance is described. The complex is adapted for the IBM PC/XT/AT computer and for ones conformant with them in the MS-DOS system, the immediate-access memory is 310 kbit. The performance is organized in an interactive mode and allows a user ignorant in programming to conduct calculations of complex hydraulic systems

  9. Debris control at hydraulic structures in selected areas of Europe. Interim report No. 1

    Wallerstein, N.; Thorne, C.R.

    1995-11-01

    This interim report contains a review of methods for managing floating debris that have been tested, and employed, at hydraulic structures in Europe. The information is taken from papers, site observations and discussions with researchers and engineers at three major European hydraulic research centers: Delft Hydraulics, The Netherlands; The Hydraulics Institute of the Technical University of Munich, Germany; and the Institute of Hydraulics, Hydrology and Glaciology at the Technical University of Zurich, Switzerland. The interim report is divided into four sections covering different types of structure and the various solutions employed. Chapter one examines run-of-river debris detention and diversion devices. Chapter two discusses debris clogging problems at spillways and assess optimum spillway design with regard to passing debris. Chapter three describes the problem of debris collection at a river hydro-electric power station and examines the solutions tested to alleviate the problem. Chapter four reviews trashrack design criteria, raking equipment and rack vibration problems. The purpose of the European element of this project, together with an ongoing investigation of debris management at US structures, is the assessment of the major debris management systems that have been employed at hydraulic structures.

  10. Evidence for internal hydraulic control in the northern Øresund

    Nielsen, Morten Holtegaard

    a contraction in the northern Oslashresund and the shallow Drogden sill at the entrance to the Baltic. The observations show that the two-layer flows through the contraction are often hydraulically controlled. The observations also reveal details of the transition from subcritical to supercritical...... flow. In terms of the composite Froude number, on the basis of local flow parameters these details are that the flow may be subcritical as well as supercritical in different areas of some cross section. Existing theories on rotating hydraulics are unable to account for these circumstances, which are...... due to the strong influence of the Earth's rotation and the curvature of the streamlines. In the present study it is not attempted to explain these conditions, but the probable effects of rotation and curvature on the controlled flow rate are discussed briefly. Also, the possible effects of hydraulic...

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

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

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

    Aisopou, Angeliki; Stoianov, Ivan; Graham, Nigel; Karney, Bryan

    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...

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

    Aisopou, Angeliki; Stoianov, Ivan; Graham, Nigel; Karney, Bryan

    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 coeff...

  14. Water hydraulic applications in hazardous environments

    Water hydraulic technology provides several advantages for devices operating in critical environment. Though water hydraulics has traditionally been used in very rough applications, gives recent strong development of components possibility to build more sophisticated applications and devices with similar capacity and control properties than those of oil hydraulics without the disadvantages of oil hydraulic systems. In this paper, the basic principles, possibilities and advantages of water hydraulics are highlighted, some of the most important design considerations are presented and recent developments of water hydraulic technology are presented. Also one interesting application area, ITER fusion reactor remote handling devices, are discussed. (Author)

  15. Water hydraulic applications in hazardous environments

    Water hydraulic technology provides several advantages for devices operating in critical environments. Though water hydraulics has traditionally been used in very rough applications, gives recent strong development of components possibility to build more sophisticated applications and devices with similar capacity and control properties than those of oil hydraulics without the disadvantages oil hydraulic systems. In this paper, the basic principles, possibilities and advantages of water hydraulics, some of the most important design considerations and recent developments of water hydraulic technology are presented. Also one interesting application area, ITER fusion reactor remote handling devices, are discussed. (UK)

  16. Hydraulic Fracturing Treatment Controls on Induced Microseismicity Attributes

    Reyes-Montes, J. M.; Kelly, C.; Huang, J.; Zhao, X.; Young, R. P.

    2014-12-01

    Hydraulic fracturing imposes stress changes in the treated rock through the injection of a mix of fluid and proppant at variable rates and can result in stimulated microseismicity (induced or triggered) with a wide range of magnitudes associated to the opening of new cracks or the mobilisation of pre-existing fractures. Optimizing the treatment is vital for the economic and sustainable development of hydrocarbon reservoir and for the minimization of potential environmental impacts. The analysis of the induced seismicity and of event parameters provide an estimate of the effect of the treatment and the extent of the changes in the rock reservoir properties affecting fluid conductivity. This gives critical feedback for the optimization of the treatment, especially during real-time monitoring. In this study, we correlate microseismic attributes such as the fracture dimensions, event distribution and b-values with the fluid treatment parameters such as the pumping pressure and the slurry rate across different reservoir treatments. Although the microseismic attributes are influenced by many different factors such as the reservoir elastic properties, the stress regime and in-situ fracturing, we consistently observed positive correlations between the slurry rate, plateau treatment pressure and the fracture dimensions. In addition, the variation and systematic deviation of b-value from the natural average of 1.0 gives an insight into the geomechanical behavior of the reservoir. Similar to b-value, another fractal dimension, D-value, indicates the fracture spatial propagation from linear advancement (D=1.0) to planar distribution (D=2.0) to full space occurrence (D=3.0). By merging microseismic events from multiple treatment stages, we statistically analyzed magnitude distribution and spatial and temporal structure of the microseismic cloud induced during the stimulation of a range of different reservoirs with a total population of ~20,000 MS events. Analysis on multiple treatment projects can provide a first order guidance on selecting optimal treatment parameters.

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

    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.

  18. Engineered Barrier System Thermal-Hydraulic-Chemical Column Test Report

    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

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

    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)

  20. Incorporating Artificial Neural Networks in the dynamic thermal-hydraulic model of a controlled cryogenic circuit

    Carli, S.; Bonifetto, R.; Savoldi, L.; Zanino, R.

    2015-09-01

    A model based on Artificial Neural Networks (ANNs) is developed for the heated line portion of a cryogenic circuit, where supercritical helium (SHe) flows and that also includes a cold circulator, valves, pipes/cryolines and heat exchangers between the main loop and a saturated liquid helium (LHe) bath. The heated line mimics the heat load coming from the superconducting magnets to their cryogenic cooling circuits during the operation of a tokamak fusion reactor. An ANN is trained, using the output from simulations of the circuit performed with the 4C thermal-hydraulic (TH) code, to reproduce the dynamic behavior of the heated line, including for the first time also scenarios where different types of controls act on the circuit. The ANN is then implemented in the 4C circuit model as a new component, which substitutes the original 4C heated line model. For different operational scenarios and control strategies, a good agreement is shown between the simplified ANN model results and the original 4C results, as well as with experimental data from the HELIOS facility confirming the suitability of this new approach which, extended to an entire magnet systems, can lead to real-time control of the cooling loops and fast assessment of control strategies for heat load smoothing to the cryoplant.

  1. 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

    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 records on EHC and IA pipe failures in the CODAP Event Database. Over 90% of the recorded EHC pipe failures and almost 50% of the recorded IA pipe failure events have resulted in manual or automatic reactor trip. A pipe failure in EHC and IA piping often results in a reactor trip, therefore, the following actions are recommended for avoiding the trips caused by small diameter piping: - Critical parts of small diameter piping should be included into the preventive maintenance program of plant. - Tolerance of shutdown systems against faults of their supporting EHC and IC systems should be analysed and number of redundant components should be increased, if necessary. (authors)

  2. METHODOLOGY FOR PARAMETER CALCULATION OF DISK BRAKE MECHANISMS WITH HYDRAULIC CONTROL

    O. S. Rukteshel

    2014-11-01

    Full Text Available The paper describes a new methodology for a parameter calculation of a disk brake mechanism with hydraulic control that allows to determine a value of hysteresis losses in a brake at the design stage with high accuracy. A complex analysis for obtaining qualitative and quantitative evaluation of design brake parameter influence on hysteresis value in it is presented in the paper.

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

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

    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...

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

    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.

  5. Experimental study on steady state property of hydraulic drive control rod

    An amount of experimental study on steady state property of step cylinder for Hydraulic Drive Control Rod has been achieved, the author obtained the flow margin on steady state property of hydraulic step cylinder, and analyzed the relationship between steady state and design parameters of step cylinder. The results is: the design parameters of step cylinder, weight,size of opposite hole et al, determines the flow margin. The maximum and the minimum holding flow in steady state increase by temperature. The holding flow in different step position at same temperature is the same

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

    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

  7. Linear Perturbation Adaptive Control of Hydraulically Driven Manipulators

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

    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...

  8. Fuzzy robust nonlinear control approach for electro-hydraulic flight motion simulator

    Han Songshan

    2015-02-01

    Full Text Available A fuzzy robust nonlinear controller for hydraulic rotary actuators in flight motion simulators is proposed. Compared with other three-order models of hydraulic rotary actuators, the proposed controller based on first-order nonlinear model is more easily applied in practice, whose control law is relatively simple. It not only does not need high-order derivative of desired command, but also does not require the feedback signals of velocity, acceleration and jerk of hydraulic rotary actuators. Another advantage is that it does not rely on any information of friction, inertia force and external disturbing force/torque, which are always difficult to resolve in flight motion simulators. Due to the special composite vane seals of rectangular cross-section and goalpost shape used in hydraulic rotary actuators, the leakage model is more complicated than that of traditional linear hydraulic cylinders. Adaptive multi-input single-output (MISO fuzzy compensators are introduced to estimate nonlinear uncertain functions about leakage and bulk modulus. Meanwhile, the decomposition of the uncertainties is used to reduce the total number of fuzzy rules. Different from other adaptive fuzzy compensators, a discontinuous projection mapping is employed to guarantee the estimation process to be bounded. Furthermore, with a sufficient number of fuzzy rules, the controller theoretically can guarantee asymptotic tracking performance in the presence of the above uncertainties, which is very important for high-accuracy tracking control of flight motion simulators. Comparative experimental results demonstrate the effectiveness of the proposed algorithm, which can guarantee transient performance and better final accurate tracking in the presence of uncertain nonlinearities and parametric uncertainties.

  9. Thermal hydraulic performance of naturally aspirated control rod housing assemblies

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

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

    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).

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

    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. Design and development of water hydraulic pressure compensated flow control valve

    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)

  13. Program system for thermal-hydraulic and thermomechanical design of fusion blanket

    A computer program system THERMECH for THERmoMECchanical and THERmal-Hydraulic design of fusion blanket has been developed. The THERMECH executes blanket design by following processes: 1) preliminary thermal-hydraulic design of blanket by one-dimensional analysis, 2) pre-processing, calculation, modifying and post-processing of two-dimensional thermal-hydraulic and thermomechanical analyses, 3) pre-processing, calculation and post-processing of three-dimensional thermomechanical analysis, 4) calculation of inelastic strain and resultant stress by one-dimensional analysis. This paper presents the outline of the THERMECH program system and the application to JAERI Tokamak Power Reactor

  14. Discrete Learning Control with Application to Hydraulic Actuators

    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 th...

  15. Material fatigue data obtained by card-programmed hydraulic loading system

    Davis, W. T.

    1967-01-01

    Fatigue tests using load distributions from actual loading histories encountered in flight are programmed on punched electronic accounting machine cards. With this hydraulic loading system, airframe designers can apply up to 55 load levels to a test specimen.

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

    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)

  17. Use of sensitivity-information for the adaptive simulation of thermo-hydraulic system codes

    Within the scope of this thesis the development of methods for online-adaptation of dynamical plant simulations of a thermal-hydraulic system code to measurement data is depicted. The described approaches are mainly based on the use of sensitivity-information in different areas: statistical sensitivity measures are used for the identification of the parameters to be adapted and online-sensitivities for the parameter adjustment itself. For the parameter adjustment the method of a ''system-adapted heuristic adaptation with partial separation'' (SAHAT) was developed, which combines certain variants of parameter estimation and control with supporting procedures to solve the basic problems. The applicability of the methods is shown by adaptive simulations of a PKL-III experiment and by selected transients in a nuclear power plant. Finally the main perspectives for the application of a tracking simulator on a system code are identified.

  18. Electromotive/hydraulic pressure type reactor control rod drives

    The mechanism of the present invention can detect an abnormality of a shock absorbing mechanism by utilizing a detection mechanism for control rod fuel insertion position upon scram without deteriorating the essential function. That is, a stopper is disposed between upper and lower two structural members of the shock absorbing mechanism for restricting relative movement in the direction of parting both of the structural members. With such a constitution, if the upper structural members should be sticked and a flush spring is kept to be compressed, the lower structural member can not protrude downward relative to the upper structural member by an effect of the stopper. Accordingly, when a piston and a control rod are extracted by an electric motor after completion of scram, although a control rod position signal of a rotation detector is changed, full insertion signal is continued to be saved from a magnetic sensor. Accordingly, if the state of both of the signals is distinguished, abnormalities of the shock absorbing mechanism can be detected. (I.S.)

  19. Effects by sea wave on thermal hydraulics of marine reactor system

    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)

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

    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)

  1. Feasibility of a Hydraulic Power Assist System for Use in Hybrid Neuroprostheses

    Foglyano, Kevin M.; Rudi Kobetic; To, Curtis S.; Bulea, Thomas C.; Schnellenberger, John R.; Audu, Musa L; Mark J. Nandor; Quinn, Roger D.; Ronald J. Triolo

    2015-01-01

    Feasibility of using pressurized hydraulic fluid as a source of on-demand assistive power for hybrid neuroprosthesis combining exoskeleton with functional neuromuscular stimulation was explored. Hydraulic systems were selected as an alternative to electric motors for their high torque/mass ratio and ability to be located proximally on the exoskeleton and distribute power distally to assist in moving the joints. The power assist system (PAS) was designed and constructed using off-the-shelf com...

  2. Hydraulic turbines

    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

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

    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.

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

    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

  5. Hybrid Control System for the ATLAS Facility

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

  6. Experimental assessment of control plug hydraulics in PFBR

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

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

    Sharma, Anitha Kumari; Guildal, T.; Thomsen, H. A. R.; Mikkelsen, Peter Steen

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

  8. Development of MARS for multi-dimensional and multi-purpose thermal-hydraulic system analysis

    MARS (Multi-dimensional Analysis of Reactor Safety) code is being developed by KAERI for the realistic thermal-hydraulic simulation of light water reactor system transients. MARS 1.4 has been developed as a final version of basic code frame for the multi-dimensional analysis of system thermal-hydraulics. Since MARS 1.3, MARS 1.4 has been improved to have the enhanced code capability and user friendliness through the unification of input/output features, code models and code functions, and through the code modernization. Further improvements of thermal-hydraulic models, numerical method and user friendliness are being carried out for the enhanced code accuracy. As a multi-purpose safety analysis code system, a coupled analysis system, MARS/MASTER/CONTEMPT, has been developed using multiple DLL (Dynamic Link Library) techniques of Windows system. This code system enables the coupled, that is, more realistic analysis of multi-dimensional thermal-hydraulics (MARS 2.0), three-dimensional core kinetics (MASTER) and containment thermal-hydraulics (CONTEMPT). This paper discusses the MARS development program, and the developmental progress of the MARS 1.4 and the MARS/MASTER/CONTEMPT focusing on major features of the codes and their verification. It also discusses thermal hydraulic models and new code features under development. (author)

  9. A quantitative analysis of hydraulic interaction processes in stream-aquifer systems.

    Wang, Wenke; Dai, Zhenxue; Zhao, Yaqian; Li, Junting; Duan, Lei; Wang, Zhoufeng; Zhu, Lin

    2016-01-01

    The hydraulic relationship between the stream and aquifer can be altered from hydraulic connection to disconnection when the pumping rate exceeds the maximum seepage flux of the streambed. This study proposes to quantitatively analyze the physical processes of stream-aquifer systems from connection to disconnection. A free water table equation is adopted to clarify under what conditions a stream starts to separate hydraulically from an aquifer. Both the theoretical analysis and laboratory tests have demonstrated that the hydraulic connectedness of the stream-aquifer system can reach a critical disconnection state when the horizontal hydraulic gradient at the free water surface is equal to zero and the vertical is equal to 1. A boundary-value problem for movement of the critical point of disconnection is established for an analytical solution of the inverted water table movement beneath the stream. The result indicates that the maximum distance or thickness of the inverted water table is equal to the water depth in the stream, and at a steady state of disconnection, the maximum hydraulic gradient at the streambed center is 2. This study helps us to understand the hydraulic phenomena of water flow near streams and accurately assess surface water and groundwater resources. PMID:26818442

  10. A quantitative analysis of hydraulic interaction processes in stream-aquifer systems

    Wang, Wenke; Dai, Zhenxue; Zhao, Yaqian; Li, Junting; Duan, Lei; Wang, Zhoufeng; Zhu, Lin

    2016-01-01

    The hydraulic relationship between the stream and aquifer can be altered from hydraulic connection to disconnection when the pumping rate exceeds the maximum seepage flux of the streambed. This study proposes to quantitatively analyze the physical processes of stream-aquifer systems from connection to disconnection. A free water table equation is adopted to clarify under what conditions a stream starts to separate hydraulically from an aquifer. Both the theoretical analysis and laboratory tests have demonstrated that the hydraulic connectedness of the stream-aquifer system can reach a critical disconnection state when the horizontal hydraulic gradient at the free water surface is equal to zero and the vertical is equal to 1. A boundary-value problem for movement of the critical point of disconnection is established for an analytical solution of the inverted water table movement beneath the stream. The result indicates that the maximum distance or thickness of the inverted water table is equal to the water depth in the stream, and at a steady state of disconnection, the maximum hydraulic gradient at the streambed center is 2. This study helps us to understand the hydraulic phenomena of water flow near streams and accurately assess surface water and groundwater resources. PMID:26818442

  11. A quantitative analysis of hydraulic interaction processes in stream-aquifer systems

    Wang, Wenke; Dai, Zhenxue; Zhao, Yaqian; Li, Junting; Duan, Lei; Wang, Zhoufeng; Zhu, Lin

    2016-01-01

    The hydraulic relationship between the stream and aquifer can be altered from hydraulic connection to disconnection when the pumping rate exceeds the maximum seepage flux of the streambed. This study proposes to quantitatively analyze the physical processes of stream-aquifer systems from connection to disconnection. A free water table equation is adopted to clarify under what conditions a stream starts to separate hydraulically from an aquifer. Both the theoretical analysis and laboratory tests have demonstrated that the hydraulic connectedness of the stream-aquifer system can reach a critical disconnection state when the horizontal hydraulic gradient at the free water surface is equal to zero and the vertical is equal to 1. A boundary-value problem for movement of the critical point of disconnection is established for an analytical solution of the inverted water table movement beneath the stream. The result indicates that the maximum distance or thickness of the inverted water table is equal to the water depth in the stream, and at a steady state of disconnection, the maximum hydraulic gradient at the streambed center is 2. This study helps us to understand the hydraulic phenomena of water flow near streams and accurately assess surface water and groundwater resources.

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

    C Castillo; Pérez, R; J. A. Gómez

    2013-01-01

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

  13. Groundwater pollution control : a challenge to hydraulic research

    Kobus, Helmut

    1993-01-01

    Groundwater constitutes a major natural resource for drinking water supply. The serious deterioration of groundwater quality observed in all industrialized and densely populated countries can be considered as an unspectacular, but ubiquitous "man-caused environmental disaster". Groundwater management has to match the increasing demands of drinking water supply (and other uses) with the constraints of the natural groundwater system with respect to both quantity and quality. In this paper, grou...

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

    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

  15. The hydraulic calculation of FFR's control assembly in steady condition

    The duct of FFR's control assembly is of hexagonal shape outside and of round shape inside, 7 absorber rods in triangular lattice with wrapped wire for spacer are fixed in a movable round thimble. In order to reduce the flow rate in annular gap, a maze design is used in the both ends of the duct. Except the differential static pressure, the pressure losses in the bundle and maze are the main parts of the total pressure drops in bundle subchannels and gap subchannels respectively. Therefore, the selection of the 4 physical model and its calculation errors are mainly fallen on the final computation precision. This report described the influence of the maze structure parameters, especially the effect of width of the gap on the resistance coefficient, and a current optimum design criteria for the maze was set up. In the calculation of the pressure drop induced by the bundle, three methods including K.Rehme model, E.H.Novendstern model and C.Chiu model were selected, and two codes named HYFC1 and HYFCA were developed. Author considers that the model 3 is more suitable for this structure through analyses and comparison of the results. The main calculation results are given

  16. Neurofuzzy controller based full vehicle nonlinear active suspension systems

    Aldair, Abdulshaheed Abdulhammed

    2012-01-01

    To design a robust controller for active suspension systems is very important for guaranteeing the riding comfort for passengers and road handling quality for a vehicle. In this thesis, the mathematical model of full vehicle nonlinear active suspension systems with hydraulic actuators is derived to take into account all the motions of the vehicle and the nonlinearity behaviours of the active suspension system and hydraulic actuators. Four robust control types are designed and the comparisons ...

  17. Summary of the thermal hydraulic design of existing and proposed LANL target systems

    The thermal hydraulics of three LANL target systems - the existing Lujan Center target, the LRIP target system, and the LPSS target system - are summarized. The existing Lujan Center target system was designed for 80 kW of beam power, while the LRIP target system is designed for 160 kW. The LPSS target is designed for 1 MW of beam power. (author)

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

    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.

  19. Resource-Saving Technique of Hydraulic Calculation of Distributing Gas-Systems

    A. Y. Savastsiyonak

    2014-06-01

    Full Text Available It is possible to consider a hydraulic calculation technique of distributing gas-systems as a combination of factors that influence on the cost of construction and maintenance of gas-distributing system. The paper contains proposal of a new specification of economic distribution of calculated pressure differential in the system sections; optimum initial flow distribution from the point of view of reliability and economy and taking into account linkage of system rings.The program of hydraulic calculation of low-pressure distributing gas-systems has been developed. While calculating combined systems consisting of steel and polyethylene gas lines reduction in discounted expenses constitutes up to 4 %.

  20. A hydraulic test stand for demonstrating the operation of Eaton’s energy recovery system (ERS)

    Wang, Meng; Danzl, Per; Mahulkar, Vishal; Piyabongkarn, Damrongrit (Neng); Brenner, Paul

    2016-01-01

    Fuel cost represents a significant operating expense for owners and fleet managers of hydraulic off-highway vehicles. Further, the upcoming Tier IV compliance for off-highway applications will create further expense for after-treatment and cooling. Solutions that help address these factors motivate fleet operators to consider and pursue more fuelefficient hydraulic energy recovery systems. Electrical hybridization schemes are typically complex, expensive, and often do not satisfy customer pay...

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

    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

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

    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...

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

    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)

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

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

  5. Plant hydraulic controls over ecosystem responses to climate-enhanced disturbances

    Mackay, D. S.; Ewers, B. E.; Reed, D. E.; Pendall, E.; McDowell, N. G.

    2012-12-01

    Climate-enhanced disturbances such as drought and insect infestation range in severity, contributing minor to severe stress to forests including forest mortality. While neither form of disturbance has been unambiguously implicated as a mechanism of mortality, both induce changes in water, carbon, and nutrient cycling that are key to understanding forest ecosystem response to, and recovery from, disturbance. Each disturbance type has different biophysical, ecohydrological, and biogeochemical signatures that potentially complicate interpretation and development of theory. Plant hydraulic function is arguably a unifying control over these responses to disturbance because it regulates stomatal conductance, leaf biochemistry, carbon (C) uptake and utilization, and nutrient cycling. We demonstrated this idea by focusing on water and C, including non-structural (NSC), resources, and nitrogen (N) uptake across a spectrum of forest ecosystems (e.g., northern temperate mixed forests, lodgepole pine forests in the Rocky Mountains, and pinon pine - juniper woodlands in New Mexico) using the Terrestrial Regional Ecosystem Exchange Simulator (TREES). TREES is grounded in the biophysics of water movement through soil and plants, respectively via hydraulic conductivity of the soil and cavitation of xylem. It combines this dynamic plant hydraulic conductance with canopy biochemical controls over photosynthesis, and the dynamics of structural and non-structural carbon through a carbon budget that responds to plant hydraulic status. As such, the model can be used to develop testable hypotheses on a multitude of disturbance and recovery responses including xylem dysfunction, stomatal and non-stomatal controls on photosynthesis and carbon allocation, respiration, and allocation to defense compounds. For each of the ecosystems we constrained and evaluated the model with allometry, sap flux and/or eddy covariance data, leaf gas exchange measurements, and vulnerability to cavitation data. Disturbances included declining water tables and canopy defoliators (northern temperature forests), bark beetles and associated blue-stain fungi (coniferous forests), and prolonged drought with bark beetles (semi-arid woodland). We show that C dynamics in trees that experience water-limitation, insect attack, or a combination of both disturbance types cannot be explained solely from hydraulic status or NSC, but are better explained by a combination of both in conjunction with N uptake. Results show that the use of plant hydraulics can yield parsimonious explanations of biophysical, ecohydrological, and biogeochemical responses to disturbance.

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

    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

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

    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

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

    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)

  9. Hydraulic High Pressure Valve Controller Using the In-Situ Pressure Difference

    Bao, Xiaoqi (Inventor); Sherrit, Stewart (Inventor); Badescu, Mircea (Inventor); Bar-Cohen, Yoseph (Inventor); Hall, Jeffery L. (Inventor)

    2016-01-01

    A hydraulic valve controller that uses an existing pressure differential as some or all of the power source for valve operation. In a high pressure environment, such as downhole in an oil or gas well, the pressure differential between the inside of a pipe and the outside of the pipe may be adequately large to drive a linear slide valve. The valve is operated hydraulically by a piston in a bore. When a higher pressure is applied to one end of the bore and a lower pressure to the other end, the piston moves in response to the pressure differential and drives a valve attached to it. If the pressure differential is too small to drive the piston at a sufficiently high speed, a pump is provided to generate a larger pressure differential to be applied. The apparatus is conveniently constructed using multiport valves, which can be rotary valves.

  10. Thermal-hydraulic analysis of the Fort St. Vrain modular vault dry store system

    This paper reports on a passive, natural thermosyphon, air-cooled modular vault dry store (MVDS) system that is being constructed for the storage of nuclear spent fuel for the Fort St. Vrain (FSV) Nuclear Power Station. In support of this FSV-MVDS system, thermal-hydraulic design analyses have been performed. The objective of the analyses is to determine flow and temperature distributions within the system and thus to ensure that the maximum fuel element temperatures shall not exceed specified design limit values under various loading and unloading conditions. This paper presents the method of analysis and discusses the resulting thermal-hydraulic characteristics of the MVDS system

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

    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.)

  12. Hydraulics of horizontal wells in fractured shallow aquifer systems

    Park, Eungyu; Zhan, Hongbin

    2003-09-01

    An analysis of groundwater hydraulic head in the vicinity of a horizontal well in fractured or porous aquifers considering confined, leaky confined, and water-table aquifer boundary conditions is presented. Solutions for hydraulic heads in both leaky confined and water table aquifers are provided. The fracture model used in this study is the standard double-porosity model. The aquitard storage is included in the formula. Solutions for the confined and unconfined conditions, fractured and porous conditions, wellbore storage, and skin effect are compared. Several findings of this study are, (1) the influence of wellbore storage and skin upon the drawdown for a fractured confined aquifer is similar to that for a porous confined aquifer, (2) aquitard storage affects the intermediate time the most by delaying the drawdown, and (3) there is a significant difference between the type curves of fractured and porous confined aquifers in most aquifer boundary conditions because of the contribution of matrix storage, and such a difference disappears at the later time.

  13. How adaptable is the hydraulic system of European beech in the face of climate change-related precipitation reduction?

    Schuldt, Bernhard; Knutzen, Florian; Delzon, Sylvain; Jansen, Steven; Müller-Haubold, Hilmar; Burlett, Régis; Clough, Yann; Leuschner, Christoph

    2016-04-01

    Climate warming will increase the drought exposure of many forests world-wide. It is not well understood how trees adapt their hydraulic architecture to a long-term decrease in water availability. We examined 23 traits characterizing the hydraulic architecture and growth rate of branches and the dependent foliage of mature European beech (Fagus sylvatica) trees along a precipitation gradient (855-594 mm yr(-1) ) on uniform soil. A main goal was to identify traits that are associated with xylem efficiency, safety and growth. Our data demonstrate for the first time a linear increase in embolism resistance with climatic aridity (by 10%) across populations within a species. Simultaneously, vessel diameter declined by 7% and pit membrane thickness (Tm ) increased by 15%. Although specific conductivity did not change, leaf-specific conductivity declined by 40% with decreasing precipitation. Of eight plant traits commonly associated with embolism resistance, only vessel density in combination with pathway redundancy and Tm were related. We did not confirm the widely assumed trade-off between xylem safety and efficiency but obtained evidence in support of a positive relationship between hydraulic efficiency and growth. We conclude that the branch hydraulic system of beech has a distinct adaptive potential to respond to a precipitation reduction as a result of the environmental control of embolism resistance. PMID:26720626

  14. Proceedings of the 1991 national conference on hydraulic engineering

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

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

    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 system’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.

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

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

  17. Design, Optimization and Analysis of Hydraulic Soft Yaw System for 5 MW Wind Turbine

    Stubkier, Søren; Pedersen, Henrik C.

    2011-01-01

    reduction in fatigue and extreme loads to the yaw system and rotor shaft are possible, when utilizing the soft yaw drive concept compared to the original stiff yaw system. The physical demands of the hydraulic yaw system are furthermore examined for a life time of 20 years. The duty cycles, based on the...

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

    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 m 400 m. 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.

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

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

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

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

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

  1. Hydraulic design optimization for hollow fiber filter system

    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)

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

    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

  3. Step dynamic process of the hydraulically-driven control rod, (II). Theoretical model on step-down process

    The HCRDS (hydraulic control rod driving system) is a new type of control rod driving system, which is designed by INET (Institute of Nuclear Energy Technology) and has been put into use in 5 MW nuclear heating reactor in Tsinghua University. The purpose of this paper is to theoretically analyze the step-down process of this new technology and establish fundamental basis for further analysis and research. The experimental loop of the HCRDS and the working principle on the step-down process are introduced in this paper. The theoretical model is established on the basis of analysis, simplification and hypothesis. Also given is the accurate mathematical description of this model. The comparison between the results of this model and that of the experiment proves the rationality and feasibility of the model. The selection of the working point is also introduced. (author)

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

    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.

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

    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

  6. Thermal-hydraulic stability of a natural circulation system with nuclear feedback

    The stability of low temperature nuclear heating reactor with various subcoolings of reactor core inlet has been studied by means of simulating experiments. The thermal-hydraulic system and the data acquisition and processing system are presented. Especially, the process of realizing the simulating nuclear feedback is introduced in detail. Finally, the experimental results are discussed in the opinions of nuclear reactor physics and thermal-hydraulics. The conclusion is that the nuclear reactor can operate stably only when the subcooling of reactor core inlet is high enough

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

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

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

    Bockhorn, Britta

    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......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 Ph......D 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...

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

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

  10. Nonlinear Dynamical Analysis of Hydraulic Turbine Governing Systems with Nonelastic Water Hammer Effect

    Junyi Li; Qijuan Chen

    2014-01-01

    A nonlinear mathematical model for hydroturbine governing system (HTGS) has been proposed. All essential components of HTGS, that is, conduit system, turbine, generator, and hydraulic servo system, are considered in the model. Using the proposed model, the existence and stability of Hopf bifurcation of an example HTGS are investigated. In addition, chaotic characteristics of the system with different system parameters are studied extensively and presented in the form of bifurcation diagrams, ...

  11. European activities on crosscutting thermal-hydraulic phenomena for innovative nuclear systems

    Cheng, X., E-mail: xu.cheng@kit.edu [Karlsruhe Institute of Technology (KIT) (Germany); Batta, A. [Karlsruhe Institute of Technology (KIT) (Germany); Bandini, G. [Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA) (Italy); Roelofs, F. [Nuclear Research and Consultancy Group (NRG) (Netherlands); Van Tichelen, K. [Studiecentrum voor Kernenergie – Centre d’étude de l’Energie Nucléaire (SCK-CEN) (Belgium); Gerschenfeld, A. [Commissariat à l’Energie Atomique (CEA) (France); Prasser, M. [Paul Scherrer Institute (PSI) (Switzerland); Papukchiev, A. [Gesellschaft für Anlagen- und Reaktorsicherheit mbH (GRS) (Germany); Hampel, U. [Helmholtz-Zentrum Dresden-Rossendorf e.V. (HZDR) (Germany); Ma, W.M. [Kungliga Tekniska Högskolan (KTH) (Sweden)

    2015-08-15

    Highlights: • This paper serves as a guidance of the special issue. • The technical tasks and methodologies applied to achieve the objectives have been described. • Main results achieved so far are summarized. - Abstract: Thermal-hydraulics is recognized as a key scientific subject in the development of innovative reactor systems. In Europe, a consortium is established consisting of 24 institutions of universities, research centers and nuclear industries with the main objectives to identify and to perform research activities on important crosscutting thermal-hydraulic issues encountered in various innovative nuclear systems. For this purpose the large-scale integrated research project THINS (Thermal-Hydraulics of Innovative Nuclear Systems) is launched in the 7th Framework Programme FP7 of European Union. The main topics considered in the THINS project are (a) advanced reactor core thermal-hydraulics, (b) single phase mixed convection, (c) single phase turbulence, (d) multiphase flow, and (e) numerical code coupling and qualification. The main objectives of the project are: • Generation of a data base for the development and validation of new models and codes describing the selected crosscutting thermal-hydraulic phenomena. • Development of new physical models and modeling approaches for more accurate description of the crosscutting thermal-hydraulic phenomena. • Improvement of the numerical engineering tools for the design analysis of the innovative nuclear systems. This paper describes the technical tasks and methodologies applied to achieve the objectives. Main results achieved so far are summarized. This paper serves also as a guidance of this special issue.

  12. European activities on crosscutting thermal-hydraulic phenomena for innovative nuclear systems

    Highlights: • This paper serves as a guidance of the special issue. • The technical tasks and methodologies applied to achieve the objectives have been described. • Main results achieved so far are summarized. - Abstract: Thermal-hydraulics is recognized as a key scientific subject in the development of innovative reactor systems. In Europe, a consortium is established consisting of 24 institutions of universities, research centers and nuclear industries with the main objectives to identify and to perform research activities on important crosscutting thermal-hydraulic issues encountered in various innovative nuclear systems. For this purpose the large-scale integrated research project THINS (Thermal-Hydraulics of Innovative Nuclear Systems) is launched in the 7th Framework Programme FP7 of European Union. The main topics considered in the THINS project are (a) advanced reactor core thermal-hydraulics, (b) single phase mixed convection, (c) single phase turbulence, (d) multiphase flow, and (e) numerical code coupling and qualification. The main objectives of the project are: • Generation of a data base for the development and validation of new models and codes describing the selected crosscutting thermal-hydraulic phenomena. • Development of new physical models and modeling approaches for more accurate description of the crosscutting thermal-hydraulic phenomena. • Improvement of the numerical engineering tools for the design analysis of the innovative nuclear systems. This paper describes the technical tasks and methodologies applied to achieve the objectives. Main results achieved so far are summarized. This paper serves also as a guidance of this special issue

  13. Mechanical Engineering Design Project report: Enabler control systems

    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. Turbulent Motion of Liquids in Hydraulic Resistances with a Linear Cylindrical Slide-Valve

    Velescu, C.; Popa, N. C.

    2015-01-01

    We analyze the motion of viscous and incompressible liquids in the annular space of controllable hydraulic resistances with a cylindrical linear slide-valve. This theoretical study focuses on the turbulent and steady-state motion regimes. The hydraulic resistances mentioned above are the most frequent type of hydraulic resistances used in hydraulic actuators and automation systems. To study the liquids' motion in the controllable hydraulic resistances with a linear cylindrical slide-valve, th...

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

    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)

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

    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

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

    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/m³. EMor and PMor mixtures followed the information given by the manufacturers and lab experience. Tests on concrete samples were carried out in laboratory simulating normally found environmental situations in order to control the mechanical resistance and the aging imposed conditions, such as solar radiation and humidity. Also, physicochemical characterizing tests were made for all used materials. From the analyzed results, two of them presented a higher performance: the EMor and SFmo. SFco presented good adherence to the RefC and good mechanical performance. However, it also presented apparent metal corrosion in humidity tests, being indicated for use, with caution, as an intermediate layer in underwater repairs. In a general classification, considering all tests, including their field applications, the better performance material systems were EMor- SFmo> SFco> PMor.

  18. Control Configuration Selection for Multivariable Descriptor Systems

    Shaker, Hamid Reza; Stoustrup, Jakob

    from power systems, hydraulic systems to heat transfer, and chemical processes. The focus of this paper is on the problem of control configuration selection for multivariable descriptor systems. A gramian-based interaction measure for control configuration selection of such processes is described in......Control configuration selection is the procedure of choosing the appropriate input and output pairs for the design of SISO (or block) controllers. This step is an important prerequisite for a successful industrial control strategy. In industrial practices it is often the case that the system, which...... is needed to be controlled, is either in the descriptor form or can be represented in the descriptor form. Singular systems and the differential algebraic equation (DAE) systems are among these systems. Descriptor systems appear in the variety of fields to describe the practical processes ranging...

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

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

    2010-03-01

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

  20. HYDRAULIC UNITS FOR DRIVING SYSTEMS OF RUNNING EQUIPMENT IN ROAD CONSTRUCTION MACHINERY

    A. Ja. Kotlobai

    2016-02-01

    Full Text Available Operational efficiency of multi-functional road construction machines depends on number of working bodies which are simultaneously performing technological operations. Systems for propulsion pto to the running equipment drive and active working bodies of road construction machines are developing in the way of using three-axis hydraulic drives. When designing a hydraulic system for road construction machinery dividing of power flow from propulsion to the running equipment drive and active working bodies is considered as rather essential problem. Leading companies do not pay attention to the development of flow divider designs, preferring to produce more expensive multi-flow pumps. One of the ways to increase efficiency of multi-functional road construction machinery is an implementation of running equipment hydraulic driving system based on a mono-aggregate pump unit which consists of a pump and a volumetric divider of power fluid flow. A principle of volumetric division and summing-up of power fluid flows, technical realization and methodology for calculation of key parameters of discrete flow distributors has been developed on the basis of discrete hydraulics regulations. The paper presents results of mathematical modeling of hydraulic systems equipped with the discrete flow distributor. Analysis of a dual-motor hydraulic drive operation has shown the following results: a discrete flow distributor ensures independent load mode of the current consumer circuit operation from the load mode of the second consumer circuit within a wide range of loads; rational value of working fluid flow discretization parameter is the following value interval k = 4–6, maximum value of parameter efficiency is reached when an angular velocity of a distributor rotor coincides with the angular velocity of a pump shaft; discrete flow distributor provides a possibility to change parameters of hydraulic flow feeding in consumers’ pressure lines within a wide range due to changes in geometrical parameters of the design; discrete flow distributor should be installed either close to the pump or be integrated into its design. The developed mathematical model and methodology for determination of parameters for the discrete flow distributor allow to optimize its design. Application of the mono-aggregate pump unit which consists of a pump and a discrete flow distributor of running equipment drive in multi-functional road construction machinery permits to decrease a number of hydraulic drive pumps, to withdraw from large-sized and material-intensive pump drive gear box.

  1. Development of MCATHAS system of coupled neutronics/ thermal-hydraulics in supercritical water reactor

    The MCATHAS system of coupled neutronics/thermal-hydraulics in the supercritical water reactor is described, which considers the interaction between the obvious axial evolution of material temperature and density and the power distribution. This code is coupled externally. The MCNP code with the library of continuous cross section is used for neutronics analysis. The sub-channel code ATHAS is for thermal-hydraulics analysis and the ORIGEN code for burn-up analysis. The calculation results for the assembly of HPLWR show that the results from this code is reliable. (authors)

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

    Janniche, Gry Sander; Christensen, Anders G.; Grosen, Bernt; Kerrn-Jespersen, Henriette; Broholm, Mette Martina

    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......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...

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

    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)

  4. Design and analysis of an active optics system for a 4-m telescope mirror combining hydraulic and pneumatic supports

    Lousberg, Gregory P.; Moreau, Vincent; Schumacher, Jean-Marc; Piérard, Maxime; Somja, Aude; Gloesener, Pierre; Flebus, Carlo

    2015-09-01

    AMOS has developed a hybrid active optics system that combines hydraulic and pneumatic properties of actuators to support a 4-m primary mirror. The mirror is intended to be used in the Daniel K. Inouye Solar Telescope (DKIST, formerly the Advanced Technology Solar Telescope) that will be installed by the National Solar Observatory (NSO) atop the Haleakala volcano in Hawaii. The mirror support design is driven by the needs of (1) minimizing the support-induced mirror distortions under telescope operating conditions, (2) shaping the mirror surface to the desired profile, and (3) providing a high stiffness against wind loads. In order to fulfill these requirements, AMOS proposes an innovative support design that consist of 118 axial actuators and 24 lateral actuators. The axial support is based on coupled hydraulic and pneumatic actuators. The hydraulic part is a passive system whose main function is to support the mirror weight with a high stiffness. The pneumatic part is actively controlled so as to compensate for low-order wavefront aberrations that are generated by the mirror support itself or by any other elements in the telescope optical chain. The performances of the support and its adequacy with the requirements are assessed with the help of a comprehensive analysis loop involving finite-element, thermal and optical modellings.

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

    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)

  6. Water hydraulics in ITER divertor maintenance

    When operating in limited space and with high loads, which is typical for ITER applications, water hydraulics has several advantages compared to other means of power transmission. As a novel technology, water hydraulics includes still some limiting properties, so special solutions are necessary when dealing with systems requiring accurate control. In this paper water hydraulic solution for divertor cassette plasma facing element refurbishment operation is explained. (authors)

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

    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

  8. The hydraulics of water heating systems; 3. ed.; Hydraulik der Wasserheizung

    Roos, H.

    1995-09-01

    Interventions in the piping systems of water heating systems are required for different reasons. This book discusses the theoretical fundamentals which are needed to understand the hydraulic effects of such interventions by presenting 14 chapters, i.e. 1. hydraulic resistance, 2. hydraulic switching modes, 3. practical examples, 4. straight-way valves and piping systems, 5. pumps as actuators, 6. three-way valves and piping systems, 7. interaction of separate pumps, 8. hydraulic circuits, 9. superimposition of pumps and gravity, 10. four-way mixers, 11. discharge valves, 12. jet pumps, 13. use of computers, and 14. Tichelmann switching. (orig./HW) [Deutsch] In das Rohrleitungsnetz von Wasserheizungsanlagen wird aus verschiedenen Gruenden eingegriffen. Der vorliegende Band bespricht die theoretischen Grundlagen, die zum Verstaendnis der hydraulischen Auswirkungen von Eingriffen in das Netz notwendig sind. Der Band ist unterteilt in 14 Kapitel: 1. Hydraulischer Widerstand, 2. Hydraulische Schaltungsarten, 3. Anwendungsbeispiele, 4. Durchgangsventil und Netz, 5. Pumpen als Stellglieder, 6. Dreiwegventil und Netz, 7. Zusammenwirken oertlich getrennter Pumpen, 8. Hydraulische Schaltungen, 9. Ueberlagerung von Pumpen- und Schwerkraftwirkung, 10. Der Vierwegmischer, 11. Einsatz von Ueberstroemventilen, 12. Einsatz von Strahlpumpen, 13. Computereinsatz, 14. Tichelmannschaltung. (orig./HW)

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

    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…

  10. Hydraulics and pneumatics a technician's and engineer's guide

    Parr, Andrew

    2013-01-01

    Hydraulics and Pneumatics: A Technician's and Engineer's Guide provides an introduction to the components and operation of a hydraulic or pneumatic system. This book discusses the main advantages and disadvantages of pneumatic or hydraulic systems.Organized into eight chapters, this book begins with an overview of industrial prime movers. This text then examines the three different types of positive displacement pump used in hydraulic systems, namely, gear pumps, vane pumps, and piston pumps. Other chapters consider the pressure in a hydraulic system, which can be quickly and easily controlled

  11. Instrumentation control system

    This book explains instrumentation control system, which mentions summary, basic theory, kinds, control device, and design of each instrumentation system. The contents of this book are introduction of instrumentation system, temperature detector, pressure sensor, flow detector, level detector, ingredient detector, signal convert and transmission, instructions, record and control of instrumentation system, PID controller control valve of instrumentation system, instrumentation equipment of water system, instrumentation facility of thermal power plant, examples of advance instrumentation facility and install and design of instrumentation system.

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

    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

  13. Hydraulic analysis of the emergency core cooling system of the RP-10 reactor

    This work shows calculation for the hydraulic analysis of the Emergency Core Cooling System (ECCS) of the RP-10 Reactor. This analysis is necessary for the design of such system. According to calculation results shown in the graphics, a pipe line of two inches of nominal diameter should be selected for such system and a maximum flow of 5 m3/h should be reached

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

    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.

  15. Chapter 13. Industrial Application of Tap Water Hydraulic Systems

    Conrad, Finn; Adelstorp, Anders

    Design and application of modern pure tap water components and systems in industries, in particular food processing industry.......Design and application of modern pure tap water components and systems in industries, in particular food processing industry....

  16. Reliability of thermal-hydraulic passive safety systems

    The scholar will be informed of reliability concepts applied to passive system adopted for nuclear reactors. Namely, for classical components and systems the failure concept is associated with malfunction of breaking of hardware. In the case of passive systems the failure is associated with phenomena. A method for studying the reliability of passive systems is discussed and is applied. The paper deals with the description of the REPAS (Reliability Evaluation of Passive Safety System) methodology developed by University of Pisa (UNIPI) and with results from its application. The general objective of the REPAS methodology is to characterize the performance of a passive system in order to increase the confidence toward its operation and to compare the performances of active and passive systems and the performances of different passive systems

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

    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)

  18. The Thermal Hydraulic Test of the MEGAPIE Cooling System and System Code Validation

    The MEGAPIE project undertaking in Paul Scherrer Institute (PSI) aims at design, building, operating and decommissioning a 1 MW liquid-metal spallation target. The design and manufacturing phases are almost finished. The target and the required ancillary systems were installed on a test facility called MEGAPIE Integral Test Stand (MITS). The cooling system is among the ancillary systems being tested. A series of thermal hydraulic tests were conducted for testing the main functions of the cooling system. These tests were focused on obtaining data about the system's stability, cooling capacity, and the transient responses. The consistency of the data was checked by comparing the heat balance between the input and output power of each heat exchanger (HEX) in the system. The main flow in the target can only be determined by the thermal balance because the built in flow meter did not work properly. The steady state pump speed, flow rates, and overall heat transfer coefficients (OHTC) of the whole cooling system were measured and analyzed for characterization of the system. Those results were used to refine numerical model of the system. A special version of RELAP5/Mod3.2.2 implemented with the fluid properties of LBE was used for the simulation study. Two cases of 'beam trip' transients were simulated and compared with test results. The agreements were good in both cases and the main features of the transients were captured by the RELAP5. This was the first step of validating RELAP5 model. (authors)

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

    Schreiber, Jeffrey G.; Geng, Steven M.

    1987-01-01

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

  20. Understanding regional and local scale hydraulic processes controlling recharge through drift

    Cuthbert, M. O.; Mackay, R.; Lawrence, A. R.; Peach, D.

    2003-04-01

    The estimation of groundwater recharge is a fundamental component of any water resources appraisal or aquifer vulnerability study. Although methods for evaluating the distribution of potential recharge leaving the soil zone are relatively well developed, the recharge signal to the underlying aquifer can be significantly modified in the presence of superficial drift deposits. Current mapping of the drift does not often provide representations of drift distribution and structure suitable for understanding the hydraulics of the subsurface flow system. The current research seeks to develop new understanding of the processes contributing to recharge in heterogeneous drift sequences, their characterisation in models and their parameterisation through field experiments. Surface and downhole geophysical sampling through regional to micro scales will be integrated with textural measurements and hydraulic monitoring to characterise drift deposits in parts of the Tern catchment (Shropshire, UK) and gain insight into the relationship between flow behaviour and geological structure. Fieldwork will then culminate in a series of flow and tracer tests at a well characterised site with continuous monitoring including the use of recently developed 4-D resistivity imaging methods to monitor the movement of natural and applied waters through the drift. Conceptual and numerical models will be used throughout the project to test ideas and drive the experimental designs. The study aims to assess the relative importance of hydraulic processes at a range of scales and, by back analysis, the degree of sophistication required in fieldwork to construct a useful model of flow patterns within the drift. The potential usefulness of various surface and downhole geophysical techniques within drift and unsaturated zone studies will be critically assessed.

  1. Experimental studies on dynamic system characteristics of the high temperature/high pressure thermal-hydraulic test facility(VISTA) for the power variation

    Dynamic system characteristics tests were carried out for the power variation by using the high temperature/high pressure thermal-hydraulic test facility, VISTA(Experimental Verification by Integral Simulation of Transient and Accidents), which had been constructed to simulate the SMART-P by KAERI. Experimental tests have been performed to investigate the thermal-hydraulic dynamic characteristics of the primary and the secondary systems in the range of 5% to 85% power. Automatic PID control logics were developed and installed to the VISTA facility to control the major thermal hydraulic parameters. Power was changed with either a step or a ramp changing method from the reference power of 10%, 25%, 50% and 75% to 5% or 10% higher power. It was found that there is no noticeable difference in the responses between a step and a ramp changing method. When unique constants of P, I, and D were used in the range of 5% to 85% power, it was found to be liable to lose the system control. Further studies are required to quantify the controllability and the time constants of the major thermal hydraulic parameters

  2. Precision digital control systems

    Vyskub, V. G.; Rozov, B. S.; Savelev, V. I.

    This book is concerned with the characteristics of digital control systems of great accuracy. A classification of such systems is considered along with aspects of stabilization, programmable control applications, digital tracking systems and servomechanisms, and precision systems for the control of a scanning laser beam. Other topics explored are related to systems of proportional control, linear devices and methods for increasing precision, approaches for further decreasing the response time in the case of high-speed operation, possibilities for the implementation of a logical control law, and methods for the study of precision digital control systems. A description is presented of precision automatic control systems which make use of electronic computers, taking into account the existing possibilities for an employment of computers in automatic control systems, approaches and studies required for including a computer in such control systems, and an analysis of the structure of automatic control systems with computers. Attention is also given to functional blocks in the considered systems.

  3. Comparative hydraulics of two fishery research circular tanks and recommendations for control of experimental bias

    Odeh, M.; Schrock, R.M.; Gannam, A.

    2003-01-01

    Hydraulic characteristics inside two research circular tanks (1.5-m and 1.2-m diameter) with the same volume of water were studied to understand how they might affect experimental bias by influencing the behavior and development of juvenile fish. Water velocities inside each tank were documented extensively and flow behavior studied. Surface inflow to the 1.5-m tank created a highly turbulent and aerated surface, and produced unevenly distributed velocities within the tank. A low-flow velocity, or "dead" zone, persisted just upstream of the surface inflow. A single submerged nozzle in the 1.2-m tank created uniform flow and did not cause undue turbulence or introduce air. Flow behavior in the 1.5-m tank is believed to have negatively affected the feeding behavior and physiological development of a group of juvenile fall chinook salmon, Oncorhynchus tshawytscha. A new inflow nozzle design provided comparable flow behavior regardless of tank size and water depth. Maintaining similar hydraulic conditions inside tanks used for various biological purposes, including fish research, would minimize experimental bias caused by differences in flow behavior. Other sources of experimental bias are discussed and recommendations given for reporting and control of experimental conditions in fishery research tank experiments.

  4. Hydraulic controls of in-stream gravel bar hyporheic exchange and reactions

    Trauth, Nico; Schmidt, Christian; Vieweg, Michael; Oswald, Sascha E.; Fleckenstein, Jan H.

    2015-04-01

    Hyporheic exchange transports solutes into the subsurface where they can undergo biogeochemical transformations, affecting fluvial water quality and ecology. A three-dimensional numerical model of a natural in-stream gravel bar (20 m 6 m) is presented. Multiple steady state streamflow is simulated with a computational fluid dynamics code that is sequentially coupled to a reactive transport groundwater model via the hydraulic head distribution at the streambed. Ambient groundwater flow is considered by scenarios of neutral, gaining, and losing conditions. The transformation of oxygen, nitrate, and dissolved organic carbon by aerobic respiration and denitrification in the hyporheic zone are modeled, as is the denitrification of groundwater-borne nitrate when mixed with stream-sourced carbon. In contrast to fully submerged structures, hyporheic exchange flux decreases with increasing stream discharge, due to decreasing hydraulic head gradients across the partially submerged structure. Hyporheic residence time distributions are skewed in the log-space with medians of up to 8 h and shift to symmetric distributions with increasing level of submergence. Solute turnover is mainly controlled by residence times and the extent of the hyporheic exchange flow, which defines the potential reaction area. Although streamflow is the primary driver of hyporheic exchange, its impact on hyporheic exchange flux, residence times, and solute turnover is small, as these quantities exponentially decrease under losing and gaining conditions. Hence, highest reaction potential exists under neutral conditions, when the capacity for denitrification in the partially submerged structure can be orders of magnitude higher than in fully submerged structures.

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

    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

  6. Electric vehicle regenerative antiskid braking and traction control system

    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.

  7. Thermal-hydraulic analyses of the loss of cooling system accidents during shutdown operations

    Son, Young Seok; Kim, Jin Hwan; Kim, Sung Kwon; Yeo, Hong Tae [Dong Eui University, Pusan (Korea)

    1999-03-01

    In this study, the thermal-hydraulic behavior following the loss cooling system accident during shutdown operations at the Yong-Gwang nuclear power plant units 5, 6 is analyzed using RELAP5/MOD3.2 code, which is necessary to develop event tree and to quantify event sequence in the development of probabilistic safety assessment methodology and integrated accident management technology during low power/shutdown operations. The related thermal-hydraulic parameters such as core damage are defined, and quantitative occurring time after the accident for these thermal-hydraulic parameters is provided. Because the analyzed plant operating states represent various core decay heat level, primary system coolant level, and available vent paths, the effects of these various parameters on plant behavior following the accident are analyzed. As one of the operator's action to mitigate the accident, the effect of gravity feed on mitigation of the accident is analyzed by performing thermal-hydraulic analysis. The results of this study can contribute to the plant safety improvement because those can provide the time for an operator to take an action to mitigate the accident by providing quantitative time of core boiling, core uncovery, and core damage. The results of this study will provide information in developing operation procedure and accident management technology. (author). 25 refs.,71 figs., 13 tabs.

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

    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.

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

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

  10. Investigation of a nonlinear dynamic hydraulic system model through the energy analysis approach

    The dynamics of a pressure regulator valve have been studied using the through Bondgraph simulation technique. This valve consists of several elements that can transmit, transform, store, and consume hydraulic energy. The governing equations of the system have been derived from the dynamic model. In solving system equations numerically, various pressure-flow characteristics across the regulator ports and orifices have been taken into consideration. This simulation study identifies some critical parameters that have significant effects on the transient response of the system. The results have been obtained using the MATLAB-SIMULINK environment. The main advantage of the proposed methodology is its ability to model the nonlinear behavior of the hydraulic resistance of system elements as a function of the fluid flow rate

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

    SONG Yunpu

    2012-10-01

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

  12. FEEDBACK LINEARISATION APPLIED ON A HYDRAULIC

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

    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 focu...... 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 possiblities and limitations. This is done based on both simulation and experimental results....

  13. FEEDBACK LINEARISATION APPLIED ON A HYDRAULIC

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

    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 possiblities and limitations. This is done based on both simulation and experimental results....

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

    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

  15. Control system design method

    Wilson, David G.; Robinett, III, Rush D.

    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.

  16. The analysis of pneumo-hydraulic accumulator efficiency, applied as element of hybrid driving system

    Chrostowski, Henryk; K?dzia, Krzysztof

    2005-01-01

    The paper presents simulating model investigations of hydraulic accumulator-working as a secondary source of energy in a multisource driving system. The simulation of the system for characteristic input functions was conducted by the use of real gas models: Benedict - Webb - Rubin (BWR) and Redlich - Kwong. The dependence of energetic efficiency of accumulator was analyzed in term of its time-constant, time of storage, number of cycles of load and it was compared to ideal gas thermodynamic pr...

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

    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.

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

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

  19. Handbook of hydraulic fluid technology

    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. Mathematical model for calculation of the heat-hydraulic modes of heating points of heat-supplying systems

    Shalaginova, Z. I.

    2016-03-01

    The mathematical model and calculation method of the thermal-hydraulic modes of heat points, based on the theory of hydraulic circuits, being developed at the Melentiev Energy Systems Institute are presented. The redundant circuit of the heat point was developed, in which all possible connecting circuits (CC) of the heat engineering equipment and the places of possible installation of control valve were inserted. It allows simulating the operating modes both at central heat points (CHP) and individual heat points (IHP). The configuration of the desired circuit is carried out automatically by removing the unnecessary links. The following circuits connecting the heating systems (HS) are considered: the dependent circuit (direct and through mixing elevator) and independent one (through the heater). The following connecting circuits of the load of hot water supply (HWS) were considered: open CC (direct water pumping from pipelines of heat networks) and a closed CC with connecting the HWS heaters on single-level (serial and parallel) and two-level (sequential and combined) circuits. The following connecting circuits of the ventilation systems (VS) were also considered: dependent circuit and independent one through a common heat exchanger with HS load. In the heat points, water temperature regulators for the hot water supply and ventilation and flow regulators for the heating system, as well as to the inlet as a whole, are possible. According to the accepted decomposition, the model of the heat point is an integral part of the overall heat-hydraulic model of the heat-supplying system having intermediate control stages (CHP and IHP), which allows to consider the operating modes of the heat networks of different levels connected with each other through CHP as well as connected through IHP of consumers with various connecting circuits of local systems of heat consumption: heating, ventilation and hot water supply. The model is implemented in the Angara data-processing complex. An example of the multilevel calculation of the heat-hydraulic modes of main heat networks and those connected to them through central heat point distribution networks in Petropavlovsk-Kamchatskii is examined.

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

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

  2. Hydraulic and pollutant removal performance of fine media stormwater filtration systems.

    Hatt, Belinda E; Fletcher, Tim D; Deletic, Ana

    2008-04-01

    Stormwater runoff from urban areas has multiple negative hydrologic and ecological impacts for receiving waters. Fine media stormwater filtration systems have the potential to mitigate these effects, through flow attenuation and pollutant removal. This work provides an overall assessment of the hydraulic and pollutant removal behavior of sand- and soil-based stormwater filters at the laboratory scale. The influence of time, cumulative inflow sediment, cumulative water volume, wetting and drying, and compaction on hydraulic capacity was investigated. The results suggested that the primary cause of hydraulic failure was formation of a clogging layer at the filter surface. Loads of sediment and heavy metals were effectively retained; however,the soil-based filters leached nitrogen and phosphorus for the duration of the experimental period. Media pollutant profiles revealed significant accumulation of all pollutants in the top 20% of the filter profile, suggesting that elevated discharges of nutrients was due to leaching of native material, rather than failure to remove incoming pollutants. It is recommended that the top 2-5 cm of the filter surface be scraped off every two years to prevent hydraulic failure; this will also avoid excessive accumulation of heavy metals, which may otherwise have been of concern. PMID:18504993

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

    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

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

    Wissam H. Al-Mutar

    2015-01-01

    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 compa...

  5. Experimental study on resistance coefficient of chamfer-hole for hydraulic drive control rod

    An amount of experimental study on resistance coefficient of chamfer-hole for Hydraulic Drive Control Rod has been achieved. The author obtained the resistance coefficient of chamfer-hole and the curve of resistance coefficient versus the displacement from chamfer to hole, and analyzed the relationship between the resistance coefficient and the structural parameters of chamfer-hole. The results are: with increased displacement, the resistance coefficient reduces rapidly from the higher level to the lower level, then increases rapidly to the original level, thus forms a wide symmetry trough, increased the chamfer's height, the width of the trough part increases, and the resistance coefficient varies in the region where the chamfer and the hole don't face each other; the larger the inner tube hole, the less the resistance coefficient, and the weaker its effect on the resistance coefficient. After reaching a certain value, further increase of the inner tube hole does not affect the resistance coefficient

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

    Na, Young Su; Ha, Kwang Soon; Park, Rae Joon; Park, Jong Hwa [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Cho, Song Won [Nuclear Safety Evaluation, Daejeon (Korea, Republic of)

    2014-12-15

    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.

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

    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.

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

    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

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

    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)

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

    M. Maharjan

    2009-04-01

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

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

    M. Maharjan

    2008-06-01

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

  12. Petri Net Model and Reliability Evaluation for Wind Turbine Hydraulic Variable Pitch Systems

    Xiyun Yang

    2011-06-01

    Full Text Available Based on an analysis of the working principles of the hydraulic variable pitch system of a wind turbine, a novel Petri net model and reliability evaluation method are proposed. First, Petri net theory is adopted to build a model for each discrete state of the operation of the hydraulic pitch system of the wind turbine and at the same time a fault Petri net model is established. Then through qualitative analysis and quantitative calculations based on the fault Petri net, the system reliability indexes are obtained. During the qualitative analysis process, in order to more conveniently find the minimal cut sets of the fault Petri net, a Visual C++ 6.0-based algorithm is compiled and the minimal cut sets are tested correctly with another method. During the quantitative calculation process, the fault probability has been obtained from the equations according to the fault probability of libraries and transitions between different states. Not only does the proposed Petri net describe the structure, function and operation of the hydraulic pitch system with a graphic language, but the fault Petri net model can also clearly express the logical relations among faults. The novel Petri net model offers simple calculations and the prospect of broad applicability and the new reliability evaluation method provides an important reference for the performance evaluation of these systems.

  13. TARN control system

    During the construction of TARN, many kinds of equipments for the accelerator have been developed and many advances in the control system have been made successfully. Main parts of the control system are management of timing control, inter-locking, data logging and interfacing of computer control. Present paper describes the design conception of the TARN control system as well as the details of the construction. Considerations about cabling and standardization of control parts are also presented. (author)

  14. Synergic hydraulic and nutritional feedback mechanisms control surface patchiness of biological soil crusts on tertiary sands at a post-mining site

    Fischer Thomas

    2014-12-01

    Full Text Available 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 interactions between crust patches. 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 and with pyrite weathering products, 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.

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

    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.

  16. Thermal-Hydraulic Feedback Module for BGCore System

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

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

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

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

    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)

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

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

  20. Power train and hydraulic system of a wheel loader; Fahrantrieb und Arbeitshydraulik fuer einen Radlader

    Latour, C. [Mannesmann Rexroth AG, Lohr a. Main (Germany). Rexroth Hydraulics; Beck, J. [Mannesmann Rexroth AG, Ulm (Germany). Brueninghaus Hydromatik

    2000-07-01

    Conventional hydraulic systems are unable to meet the demands on modern wheel loaders in terms of functionality, economic efficiency, comfort of operation, and environment-friendly operation, so that new electro-hydraulic concepts and components are required. The contribution presents an electrohydraulic outline concept for a wheel loader as well as detailed technical information on some of its key components. [German] Die staendig wachsenden Anforderungen an moderne Radlader in Bezug auf Funktionalitaet, Wirtschaftlichkeit, Bedienungskomfort und umweltrelevante Aspekte koennen von konventionellen hydraulischen Systemen kaum noch oder nur mit erheblichem Aufwand realisiert werden. Daher ist es erforderlich, fuer die Systeme Fahrantrieb und Arbeitshydraulik neue elektro-hydraulische Konzepte zu erarbeiten und entsprechende Komponenten zu entwickeln, die die Anforderungen in Bezug auf Technik und Kosten erfuellen. Dieser Beitrag gibt einen Ueberblick ueber ein elektrohydraulisches Gesamtkonzept fuer einen Radlader sowie detaillierte technische Informationen zu einigen Schluesselkomponenten. (orig.)

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

    Brettschneider, D.J.; Simmons, R.A. Jr. [Fernald Environmental Management Project, Cincinnati, OH (United States); Kappa, J.D.; Stover, J.A.

    1995-01-25

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

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

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

    2011-01-01

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

  3. The coupling of the thermal hydraulic system code ATHLET with 3D neutronics models

    The state of analytical methods in the field of plant transient analysis and 3D reactor core analysis is briefly described. The limitations determined by the separate analysis of both fields are discussed, and the accident conditions, which need analysis by coupled codes, are presented. The development of coupling the thermal hydraulic system code ATHLET with 3D neutronics models is described including information about the code features. Experiences from first applications are reported and an outlook on further investigations is given. (orig.)

  4. Application of gamma-rays in hydraulic conveyance pipeline systems

    Transmission measurements of gamma radiation in two selective energy channels and at two positions of the pipe may successfully be used for non-contact determinations of the most important conveyor-flow parameters such as medium density, local space concentrations, particle drift speeds and, by combination of these data, mass transport per unit time. The two-channel technique improves the accuracy of density analysis and allows, in contrast to conventional procedures, simultaneous measurements of individual volume fractions in three-component flows. If the chemical composition of one component is not constant, the range of this variation has to be investigated and to be taken into account as a systematic error. For measuring the mean drift velocity of particles, two gamma-ray gates are attached to the pipe string, one behind the other in the direction of the flow. From the dc-current modulations at both detector outputs phase shift and mean velocity can be deduced by using cross-correlation analysis. At the same time this measuring technique delivers the mean particle size and the possibility to recognise in good time imminent component plugs blocking the mass flow. In addition to these transport data relevant to the layout and operation of mining systems, the knowledge of the wear performance of the pipe string is of great importance. Activation of tube parts allows very sensitive wear measurements by detecting changes of the activity. (author)

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

    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.

  6. ISABELLE control system

    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

  7. Validation of Divertor Cassette locking system with a hydraulic jack tool

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

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

    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)

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

    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.

  10. Coordinated joint motion control system with position error correction

    Danko, George L.

    2016-04-05

    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.

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

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

  12. PLC based control system for RAM assembly test facility

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

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

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

  14. Thermal-hydraulic design concept of the solid-target system of spallation neutron source

    In relation to thermal-hydraulic design of the N-Arena solid-target system of the JHF project, heat transfer experiments were performed to obtain experimental data systematically on heat transfer coefficient and CHF for vertical upward and horizontal flows in a thin rectangular channel simulating a coolant channel of the proposed spallation neutron source. Thermal-hydraulic correlations which can be used for design calculations were proposed based on the obtained data. Finally tentative results of feasibility study on maximum beam power which could be attained with a solid target were presented. The result indicated that the condition for the onset of nucleate boiling is the most significant limiting factor to the maximum beam power. (author)

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

    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)

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

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

    2008-07-01

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

  17. Study on Wireless Network Communication in Stage Hydraulic Monitoring System Based on Internet of Things

    Yue Dong; Hui Ren; Jianghui Dong; Liping Wang

    2015-01-01

    A novel stage hydraulic monitoring system based on Internet of Things (IoT) is proposed in this paper. Compared with the traditional wired system, the proposed system is a flexible working method and can save the cost. Furthermore, it has the low power consumption, high safety, and large scale network. The real-time pressure and flow data can be collected by using the nodes in ZigBee network. The fault detection and diagnosis process was used in this study, which was facilitated by measuring ...

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

    Stecki, J. S.; Conrad, Finn; Oh, B.

    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...

  19. Technique of analysis and error detection for thermo-hydraulic system data

    Statistical techniques based on estimation theory were developed for the analysis of steady-state data from thermo-hydraulic systems, which could be either experimental loops or operating power plants. The method seeks to resolve errors in the component heat balances which describe the system, to obtain system parameter estimates which are more accurate than the raw data, and to flag possible faulty sensors. Sample results are given for the analysis of test data from the Sodium Loop Safety Faciltiy (SLSF) P3 experiment

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

    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.