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The main objective of the study was to design a pneumatic directional control valve for controlling pneumatic drives and produce it using a rapid prototyping technique. As the basic design assumption was to achieve high performance through a high flow rate and a low pressure drop, it was necessary to determine two flow parameters: the sonic conductance and the critical pressure ratio. The flow rate of compressed air and the diameters of the pneumatic conduits and fittings are important as they affect the rate of travel of the pneumatic cylinder piston. The 3D solid model of the directional control valve, developed in a CAD program, was used to simulate and optimize the flow rate. The analysis was performed by means of ANSYS CFX, a computational flow dynamics program. The main elements of the valve, i.e., the spool and the body, were produced using the PolyJet Matrix technology. The prototype was tested experimentally to determine the nominal flow-rate, calculate the flow parameters in accordance with the ISO 6358-1989 standard and compare them with the CFD simulation data. The simulation results showed very good agreement with the measurement data. The CFD analysis of the 3D solid model enabled us to optimize the flow of compressed air through the valve. The rapid prototyping method was found to be suitable to produce a fully functional directional control valve, which was confirmed through measurements at a test stand. The attempt to combine rapid prototyping used to fabricate pneumatic directional control valves with CFD used to simulate their operation was successful. The study shows that it is possible to design and construct a fully functional directional control valve characterized by high efficiency, high performance and a small pressure loss in a very short time and at a very low cost, which makes rapid prototyping superior to conventional methods of prototype making.

Stiffness control is critical in human manipulation. The ability to transition between a low stiffness state, allowing for compliant interactions with the environment, through to rigid states, where it is possible to exert high forces, enables much functionality. Particle jamming provides an elegant method of modulating stiffness online. We develop an un-actuated anthropomorphic hand, with jamming particles enclosed in the joints surrounded by a moulded silicone skin. This approach to stiffness control also allows for control of posture, through 'pre-conditioning' by interacting with the environment in a soft state and then jamming the joints when in a new posture using a single vacuum source and control valve. To demonstrate the capabilities of this new design and fabrication approach, we introduce a 'pre-conditioning' algorithm for exploiting the soft/rigid state transition and environmental interactions to fix the hand in a given demand posture. This approach allows for accurate posture control, which translates to high grasping success rates. In conclusion, we demonstrate the advantages of the new design and fabrication approach, where jamming joints can be used to passively perform a variety of tasks through pre-conditioning of the hand posture. © 2021 IEEE.

Mature Field-D has produced at recovery factor (RF) less than 20% due to its geological complexity. As per re-development plan, four wells were drilled from newly built platform in 2020. Each well was completed with combination of oil and gas zones with maximum five zones per well. The gas zone is utilized as an in-situ gas lift, considering gas lift gas shortage and anticipated future requirement for artificial lift upon pressure depletion and water breakthrough. All-electrical inflow control valve (ICV) and permanent downhole gauges (PDG) has been installed across each respective oil & gas zone. The system serves to provide zonal production control to mitigate high producing gas-oil-ratio (GOR) or water breakthrough zones. Single string multi-zone ICV completion enables maximum production from layers with varying reservoir properties and pressure depletion. In addition, gas zones completed with ICV enables cost-effective application of in-situ or well-to-well gaslift, facilitates future non-associated gas production for gas monetization project as well as gascap blowdown opportunities. Application of all-electric smart completion has enhanced proactive surveillance and provided greater production control flexibility resulting in higher production than target. From the downhole data obtained from PDG, wells and network model were updated with good certainty and used to further optimize production at well, platform and field level. Multiple ICV configuration were simulated to maximize oil, minimize gas and water production considering facilities limitation in terms of liquid handling and gas processing to reduce carbon footprint. The gas zones have been utilized for in-situ gas lift using ICV. The smart completion has also enabled efficient unloading facilitated by real-time data acquisition and production control through ICVs leading to additional cost savings. It marks the first installation of an all-electric smart completions offshore Malaysia and Asia Pacific. This paper will explain the functionality of all-electric ICV system and outlines the methodology undertaken to optimize production at well, platform and field level utilizing industry recognized well and network models.

One of the largest oil fields in the GCC was developed in the 1960's. The field was initially produced under natural depletion supplemented by gas injection. The high offtake rates led to a rapid displacement of the gas/oil contact; thus, the field has now been suffering from early gas/water breakthrough and uneven fluid influx along with the horizontal wells. The reservoir has been on production for more than 50 years. Water/gas breakthrough from fractures being the major challenge which negatively affects wells oil production rates. Applying technology which can manage water/gas breakthrough in a cost-effective manner whilst allowing increased oil production was a key goal from operators in this field. Passive Inflow Control Devices (ICD) were introduced to the global oil and gas market in mid/late-1990's, and the first generation of Autonomous ICD (AICD) that can help reduce more unwanted gas or water was first installed in 2007. ICD's successfully demonstrated that they could delay the gas and/or water breakthrough within horizontal wells, but they could not choke gas when the coning/gas-breakthrough occurred and along with limited abilities to stop unwanted water production. To help solve this problem, the Autonomous Inflow Control Devices (AICD-RCP) with a movable disc was introduced to the market and demonstrated reduction of gas production by 20-30% with similar gains in oil production[1]. In this paper, the newest generation of Autonomous Inflow Control Valve (AICV) technology is presented. The AICV technology has a movable piston that can close and reduce the unwanted gas and water production by up to 95%[2]. The application of AICVs discussed herein were deployed within several wells which had extremely high Gas Oil Ratio (GOR) and low oil production. The novel AICV technology can differentiate between fluid types based on viscosity and density. When undesired fluid (gas and/or water) starts to be produced, the AICV chokes the valve flow area gradually until completely shutting off, all without well intervention[3]. Well production performances are documenting the benefits of installing AICV completions. The results demonstrate the AICVs closing the zones with high gas production and favoring oil-rich zones. Majority of evaluated wells demonstrated clearly that the extremely high GOR was reduced; some wells have returned to solution GOR for more than two years, and at the same time, the daily oil production is increased.

This paper is a continuation of research into the causes and ways to eliminate the generation of self-oscillations in the system of automatic regulation of rotations of the free turbine in the turboshaft gas turbine engines of helicopters. The study of dynamic processes in the system of automatic regulation of free turbine’s rotations in a turboshaft GTE has shown that one of the reasons for the development of self-oscillations is the poor performance of the control valve of the type «nozzle-flap» in the rotation regulator’s hydraulic drive. At a pump-regulator plant, the criterion for the quality of control valve execution or repair implies that the geometric size of the valve parts and the flow rate of working fluid through the valve when the flap is closed meet the technical requirements. As practice shows, this is not enough. With this approach, valve defects manifest themselves only during the tests of assemblies as part of the engine. This paper proposes a method to examine the characteristics of control valves such as «nozzle-flap», as well as criteria for assessing the quality of their execution. Experimental characteristics of control valves such as «nozzle-flap» for an actual regulator of free turbine rotation frequency are given. New data on the outflow of liquid from the nozzle with a flap have been obtained. It is shown that the destruction of the stagnation zone in the nozzle tip could result in that the valve flow rate increases, which negatively affects the characteristics of the hydraulic drive and regulator in general. A technique has been proposed to improve the stability of the valve’s performance by increasing the relative length of the nozzle. It is shown that the most informative characteristic of the valve is the dependence of flow rate on the position of the flap. Based on this characteristic, it is possible to determine the criteria for rejecting valves without testing them as part of the assembly

The paper deals with the control of the test rig for measurement of the stiffness of the spring. The test rig is equipped with integrated hydraulic actuator and multilayer control system with computer vision to automate the testing process and to increase the safety of the operating staff during the testing. The integrated hydraulic actuator allows to control the piston velocity and position and to produce the force needed for the spring compression and stiffness measurement. It has an integrated manifold with four proportional flow control valves connected as the full hydraulic resistance bridge. Each control valve is controlled separately using the input signal. That makes it possible to realize different connections and control strategies of the hydraulic cylinder using the different control algorithms. The hydraulic circuit was modelled and simulated, and the achieved simulation results are presented in the paper. The test rig is controlled using the microprocessor control system and is it equipped by different transducers – position transducer, pressure transducers and force transducer to be able to collect data important for the stiffness characteristic evaluation. The upper level of the control system is created by the vision control system. The goal of the implementation of the machine vision is to decrease the number of the manual operations done by the technician by the spring testing and to extend the automatic testing cycle of the automatic computer vision-controlled movement of the actuator at the beginning of the testing cycle and finally to increase the safety of the operating staff. The structure and functionality of the designed control system, experimentally obtained results and evaluated stiffness characteristic of the tested spring are presented in the following chapters.

To satisfy the market, competition in the industrial sector aims for productivity and safety in industrial plant control systems. The appearance of a fault can compromise the system’s proper functioning process. Therefore, Fault Detection and Diagnosis (FDD) methods contribute to avoiding any undesired events, as there are techniques and methods that study the detection, isolation, identification and, consequently, fault diagnosis. In this work, a new methodology that uses faults emulation to obtain parameters similar to the Development and Application of Methods for Diagnosis of Actuators in Industrial Control Systems (DAMADICS) benchmark model will be developed. This methodology uses previous information from tests on sensors with and without faults to detect and classify the situation of the plant and, in the presence of faults, perform the diagnosis through a process of elimination in a hierarchical manner. In this way, the definition of residue signature is used as well as the creation of a decision tree. The whole process is carried out incorporating FDD techniques, through the Non-Linear Auto-Regressive Neural Network Model With Exogenous Inputs (NARX), in the diagnosis of the behavioral prediction of the signals to generate the residual values. Then, it is applied to the construction of the decision tree based on the most significant residue of a certain signal, enabling the process of acquisition and formation of the signature matrix. With the procedures in this article, it is possible to demonstrate a practical and systematic method of how to emulate faults for control valves and the possibility of carrying out an analysis of the data to acquire signatures of the fault behavior. Finally, simulations resulting from the most sensitized variables for the production of residuals that is generated by neural networks are presented, which are used to obtain signatures and isolate the flaws. The process proves to be efficient in computational time and makes it easy to present a fault diagnosis strategy that can be reproduced in other processes.

Flow control devices (FCDs) have demonstrated significant potential in improving recovery from Steam Assisted Gravity Drainage (SAGD) production wells. Passive FCDs will allow the SAGD producer well to create additional pressure drop to balance the production influx, improving overall conformance and promoting accelerated hydrocarbon production. However, passive FCDs cannot effectively restrict steam effluents once steam breakthrough at the production well occurs. The Autonomous Inflow Control Valve (AICV) actively delivers a dynamic flow restriction with the ability to choke and/or ‘shut-off’ in response to the associated viscosity and density of the fluids flowing through the AICV. This novel AICV design behaves truly autonomously based on the Hagen-Poiseuille equation and Bernoulli’s principle. The AICV utilizes the differences in flow behaviour between the laminar and turbulent flow restrictions to differentiate the pressure-drops between oil, water, gas, and steam phases. A collaborative effort has been initiated between the AICV vendor and the Computer Modelling Group to develop reservoir simulation workflows with the AICV that will allow the user to enter characteristic performance curves for a variety of SAGD and thermal fields. The development of mechanistic wellbore modelling and developed methodology to incorporate the associated complexities of AICV behaviour has shown to be an improvement to the way FCDs are currently modelled, providing insight into the potential for AICV application in SAGD and other thermal recovery operations. Such techniques allow the reservoir simulation tools to perform realistic predictions of the AICV behaviour at downhole conditions and evaluate scenarios and relative impacts of completion designs. The development of a new characterization method of AICV performance in SAGD applications, and its implementation in reservoir simulation tools, has helped to unveil the benefits of implementing AICVs in improving recovery from SAGD operations.

A butterfly valve is commonly used as control device in applications where the inlet velocity is high and the pressure drop required is relatively low. Hydrodynamic torque is a significant design parameter for engineers dealing with control valve design. Predicting the hydrodynamic torque for all opening and closing conditions in rotary valves is of utmost importance. This study sought to compare experimental and simulated computational fluid dynamics (CFD) performance factor and hydrodynamic torque of 150mm double offset butterfly disc for various opening and closing angles in the increments of 100. In general, as the flow rate increases through the valve, greater force is exerted upon the disc by the fluid. These increased dynamic forces require more torque to rotate the disc. The amount of torque required to rotate the disc during operation varies depending on type of fluid flowing through the valve, velocity, shape and position of the disc. Finally a correlation has been established between the experiment and CFD values and valve industry can make use of this data for optimum selection of gear box and actuator.

Controlling the pressure of oil wells during drilling can be one of the most complex and dangerous processes operating stage. This study proposes the design of an internal model controller (IMC) to control the pressure at the bottom of wells during drilling operations based Managed Pressure Drilling (MPD). MPD adds a control valve in the drilling system to have another manipulate variable on the well pressure. In the first part of this work, there was obtained a mathematical model of the process, which is founded on fluid mechanics (state equation, the Reynolds transport equation: continuity and momentum). The dynamic process presents an integrating element, which makes the process dynamics difficult to handle because any disturbance may alter its stability. Still it becomes more complex in the presence of a delay time in the system model. In the second part, was designed an IMC controller for controlling the integrative process with the addition of time delay looking for the best stability and robustness of the process. Finally, the proposed controller is performed by simulations that show its feasibility in the presence of common problems during drilling, which were tested as disturbances in closed loop system (loss circulation fluid, influxes, pipe addition and loss of pump power). The performance of the process in closed loop is compared with a classical PI.

Summary An extensive study was conducted to optimize the field development plan (FDP) with infill wells in water and miscible water-alternating-gas (WAG) displacement processes for high and moderately heterogeneous areas of stratified carbonate reservoir. This reservoir is complex heterogeneities with numerous fractures, high perm steaks, multiple sub-layers with variable permeability and intrabed communication with other reservoirs. Within this reservoir, the wells have dual completion through short/ long strings. It is observed that injected water /gas is flowing through high permeability layers and leaving a lot of oil in un-swept area. Therefore, in order to sustain target oil production and improve recovery, this reservoir is currently undergoing re-development with different innovations including maximum reservoir contact (MRC) wells with line drive injection pattern drilled from different artificial islands, gas lift, infill wells, different tubing size strings, different types of well completions (limited entry liner –LEL, pre perforated liner- PPL, inflow control devices- ICD and inflow control valve- ICV) and appropriate EOR technology. This article presents analytical models and a step by step work flow to optimized FDP for optimum tubing size, well spacing, vertical well placement, well length to reduce the gap between toe to heel of two wells, techno-economic viable number of infill wells and their location (vertical and areal) for maximizing the recovery and maintain the longer plateau at target production rate. An FDP is formulated with optimum tubing size, well spacing, well length, vertical well location and techno-economic viable infills in water / miscible WAG flooding for a highly heterogeneous complex stratified reservoir.

1st International Electronic Conference on Actuator Technology: Materials, Devices and Applications, IeCAT, online, 23 Nov 2020 - 27 Nov 2020; Actuators : open access journal 10(6), 133 (2021). doi:10.3390/act10060133 special issue: "Special Issue "Selected Papers from the 1st International Electronic Conference on Actuator Technology: Materials, Devices and Applications (IeCAT)" / Special Issue Editors: Prof. Dr. Jose Luis Sanchez-Rojas, Guest Editor; Dr. Tatiana Minav, Guest Editor", Published by MDPI, Basel

This paper deals with the modeling and simulation of an electro-hydraulic system. In a hydraulic system, the fluid enables the power transmission, and so, the fluid influences the overall dynamic behavior of the system. Generally, electro-hydraulic systems are highly nonlinear, accuracy, and precise position control that are the key parameters for quality hydraulic systems. A mathematical model is developed for the double acting cylinder, solenoid operated directional control valve, and proportional flow control valve. And a fuzzy model is successfully developed for the hydraulic system. Accurate position of the actuators are obtained for the corresponding change in input pressure and flow rate. The entire system is validated by comparing the experimental and fuzzy model readings by the correlation chart. Both the readings are found to be highly correlated, and this model can certainly replace the existing system.

The correction element or the final control element is the element in a control system that is responsible for transforming the output of a controller into a change in the process, and aims to correct the change in the controlled variable. This chapter discusses the pneumatic/hydraulic and electric correction control elements, along with actuators. Directional control valves are widely used in control systems as elements for switching on or switching off hydraulic and pneumatic pressures that can control the movement of some item by some actuator. A single-seated valve has the advantage compared with the double-seated valve of being able to close more tightly, but the disadvantages are that the force on the plug is greater from the fluid and so a larger area diaphragm may be needed. The discussion is restricted to those types of motors that are commonly used in control systems, this including d. c. motors and the stepper motor. Case studies have been designed to illustrate the use of correction elements discussed in this chapter.

The paper is focused on the identification of the eigenfrequency of the linear hydraulic servo drive, which consists of the flow control valve and hydraulic cylinder. The behaviour of the closed loop controlled hydraulic drive is given by the dynamic properties of the control valve and hydraulic cylinder. The dynamic properties of the hydraulic cylinder determine the structure and tuning of the controller of the closed loop position control system. For that reason it is important to know the eigenfrequency of the cylinder. The eigenfrequency of the cylinder depends on the moving mass and on the stiffness of the hydraulic cylinder, that means it depends on type of the hydraulic cylinder and on hydraulic capacities of the cylinder chambers and connecting pipelines. Due to the dependence of the hydraulic capacity on the piston position the stiffness and the eigenfrequency vary with the piston position. The identification of the eigenfrequency using the self-excited oscillations by the arranging a non-linear element in the feedback is presented in the paper. The identified curve describing the eigenfrequency of the cylinder in dependence on the piston position can be used for the controller tuning.

In pneumatic systems the supply and discharge of compressed air can be regulated by various shut-off and control valves. One of the modern decisions in this field is the usage of proportional solenoid valves. Such a valve can be represented like a equivalent throttle. Its effective area depends on the control signal and differential pressure. Pneumatic systems work processes modeling requires the development of mathematical model of this device work. Gas dynamic and electromagnetic processes in proportional valves are complex. An approximation based on an artificial neural network is proposed instead of an analytical description. Is is a three-layer feedforward neural network. Vector including the control signal and differential pressure is used to calculate the effective area. The neural network training was based on experimental data. The laboratory unit for the proportional valve investigation is described. Levenberg-Marquardt algorithm was selected for the training. Neural network model was used for plotting of the surface describing air flow through the proportional valve. Mathematical model works in the range of the differential pressure from 0 to 4 bar and in the range of the control signal from 0 to 100%.

In steam turbine control and actuation, the steam control valve plays a key role in operability and reliability. The electrohydraulic regulating system for the steam control valve, usually called the servomotor, needs to be reliable and high performing under nonlinear excitation interference in actual conditions. Currently, electrohydraulic servo valve control technology is widely used in servomotors. Although this technology has good control performance, it still has some technical defects, such as poor antipollution ability, low energy efficiency, large volume size, and limited installation space. Aiming at the abovementioned technical shortcomings of electrohydraulic servo valve control technology, a servomotor-pump-hydraulic cylinder volume control scheme is proposed in this paper, forming a pump-controlled servomotor for the steam control valve. By analyzing the working principle of the pump-controlled servomotor position control in the steam control valve, the mathematical model of a pump-controlled servomotor for the steam control valve is established. The sliding mode variable structure control strategy is proposed, and the variable structure control law is solved by constructing a switching function. To verify the performance of the proposed control method, experimental research was conducted. The research results show that the proposed sliding mode variable structure control strategy has a good control effect, which lays the theoretical and technical foundation for the engineering application and promotion of pump-controlled servomotors for steam control valves and helps the technical upgrade and product optimization of steam turbines.

Earth is known as a blue planet since 71% of it is covered with water. But the fact is that 96% of it is saline water so only 4% is available as fresh water that can be used by all life exists in the earth. So from this, it’s understood the significance of fresh water. So a proper water management system is essential for the society. Continuous monitoring of water level from the resource will give an idea that how many days more users could use water which is available in the open-well or bore-well. Attaining the water level from the source, it provides a control valve at the outlet of house-top tank which will be operated by the control action provided by the actuator according to the water level present in the source which is already assigned by user. Arduino is easier to access and more user-friendly for common people, and more than that the system operation will be easier. A GSM-based monitoring system will be more helpful for common people too. Automatic water tank filling and dry pump protection are also an essential part of this system for smooth availability of water for all household works.

Control valve stiction is a common problem faced by the process industries, which can have a strong adverse effect on the profitable operation of plants. Although various stiction detection methods based on neural networks have been proposed, few of these studies have considered the performance of stiction detection based on the use of 2D representations of the process signals. In this paper, such an approach is proposed, based on the use of a pretrained convolutional neural network, AlexNet. The proposed convolutional neural network stiction detection (CNN-SD) method showed highly satisfactory performance, which can be further applied on real industrial data.

Instabilities may occur inside turbine control valve during certain circumstances. Instabilities can be a risk for reliable operation of steam turbine. Therefore, it is important to pay attention to the research of steam turbine control valves. Doosan Skoda Power (DSPW) uses an air test rig to discover instabilities inside valves. The purpose of this article is to get acquainted with the results of experiment, which are performed during measurement with using Kulite probe (sensitive pressure transducer) mounted in diffuser throat. There can be obtained results in frequency domain from this sensitive pressure transducer. Spectrograms are complex results in the frequency domain as a varies with time. This article identifies regions with significantly high magnitudes correspond to high and low frequency regions.

Flow control valves have broad application prospects in aviation hydraulic systems. This paper proposes a combination microflow control valve (CMCV) instead of the traditional valve to optimize the performance. Influences of structural parameters of CMCV on its characteristics are numerically investigated to determine the static and dynamic characteristics of CMCV. The calculation results indicate that there is a negative feedback control between stages of the flow regulator, the orifice pressure drop is compensated, and the flow regulation deviation is reduced. The orifice area and the flow regulator valve port area have significant effects on flow characteristics. The diameter of orifice, the spring stiffness, the number of throttle holes, and the ultimate displacement of sleeve are positively correlated with the flow rate stability value of the valve. The valve port flow area gradient and initial overlap of the flow regulator affect the flow rate fluctuation range and response time of CMCV.

This chapter provides an extensive survey on the modelling and optimisation of district heating systems (DHSs) focused on the heat distribution network, an energy analysis of unbalanced central heating systems, as well as a comprehensive discussion about pump control in heating stations, analysing the energy efficiency of flow control methods. For this purpose, the major components of a DHS have been described and discussed, and their modelling has briefly reviewed including numerical simulation models for heat sources, end-users, and especially, the distribution network. The main deterministic and heuristic optimisation techniques are briefly explained. A comparative energy analysis is performed on the hot water flow rate adjustment using throttling control valves and variable-speed drives in a district heating plant constructed in Romania. To correlate the pumped flow rate with the heat demand and to ensure the necessary pressure using minimum energy, an automatic device has been designed. Additionally, the performance of a fluid temperature control system using self-adjustable cables and the main plastic materials used for the manufacturing of tubes for heat distribution in buildings are presented, and a comparative analysis of the physical, mechanical, geometric and hydraulic characteristics of the tubes produced both from classical metallic materials and from different plastic materials is performed.

During the operation of the load-sensing hydraulic drive in the mode of controlling the hydraulic engine consumption, an important parameter is a value of counterbalancing pressure differential Δp, which determines the amount of power loss. To reduce power losses and the value of counterbalancing pressure differential Δp in the mode of controlling the hydraulic engine consumption, a new scheme of load-sensing drive based on the multimode directional control valve, which includes a safety-overflow section, in which the introduction of a special plunger changes the control system parameters, which allowed to reduce the value of pressure Δp to values (0,7–0,8) MPa. Minimization of the pressure value Δp is supported by the combination of construction parameters of the overflow valve of the safety-overflow section. As a result of additional theoretical studies, it was determined that the obtained combinations of design parameters do not increase the time of the transient process and the amount of overregulation of the pressure during the operation of the hydraulic drive in the mode of controlling the hydraulic engine consumption.

This paper presents regulation of an asynchronous induction motor so as to create a stable vacuum milk pump using Variable Frequency Drive (VFD). Contribution includes providing information about the usage of the VFD, which regulates the activity of an asynchronous induction motor so that the vacuum pump milking machine creates stable vacuum. The paper describes the functional and time dependence of input values and output parameters of frequency converters at changing electric motor speed. For simulation and verification the milking process a mathematical model of the milking machine was created. The simulation was verified in Matlab/Simulink software. The constructed mathematical model showed symmetric regulation. Control model symmetry was verified at the laboratory of milking machine. The possibility to remove the control valve from milking equipment was proven using the measured data. It was found that constant vacuum values can be maintained. A constant vacuum can be maintained by changing vacuum pump speed. This control is of an accepted standard (ISO 5707: 2007). The power saving control values (on the milking equipment) of the VFD were positive throughout the measuring range. The performance of the milking vacuum pump is normally designed from the maximum air consumption of the milking machine at nominal vacuum (50 kPa), and a performance reserve is added to this. This means that the pump is operated between the ranges 7.53 and 15.06 dm3 s−1. By using a vacuum pump controlled by a VFD, power savings can be achieved from 32.50% to 54.02% compared to a control valve.

The paper presents the CFD model of a load sensing directional control valve. The model was validated experimentally in terms of pressure drop and flow force at different positions of the spool. The spool position was imposed manually by means of a micrometric screw and a load cell was used for measuring the flow force. The CFD model was developed with the CAD-embedded tool FloEFD®. The model has been proved to be very reliable in estimating the pressure drop, moreover quite good results were obtained also in the evaluation of the flow force. The CFD simulations were used to tune the coefficients of a lumped parameter model of the valve, so that such a model can be efficiently used for the simulation of an entire hydraulic circuit. Moreover, the CFD model has been used as design tool for attenuating the detrimental effect of the flow force. In particular, the width of the land upstream of the metering edge has an influence on the resultant force on the spool. If was found that it is possible to significantly reduce the flow force at maximum opening with a relatively small increment of the pressure drop across the valve.

Control valves have an important function in the warship power system. In engineering practice, the fluid oscillation inside the control valve causes the additional load to the valve actuator. When the additional load is added to the original load of the valve, it is possible that the required driving force (or driving moment) of the valve is greater than the maximum force (or moment) output by the actuator, which may cause the abnormal stop of the actuator. Conventionally, the interaction effect of the valve mechanical and electric components on the valve chamber’s flow field cannot be considered in computational fluid dynamics (CFD) simulations, so the oscillating fluid loads cannot be accurately obtained. In order to solve this problem, the mechanical-electric-fluid integrated valve model, using the FLUENT and AMESim cosimulation method, was developed to embody the interaction effect between the components of each part of the control valve and exhibit the fluid oscillation during the operating process of the control valve. Compared with the pure software simulations, the unsteady flow characteristics and dynamic response of the actuator were synchronously obtained in this study, which accurately captured the sudden fluid loads required for further compensation. At the same time, the differences in performance of different valve plugs were compared. The stability time of the valve plug and oscillation amplitude of the unstable fluid loads were distinct for control valves with different flow characteristics. The results can aid in understanding the instability mechanism of the fluid load in the control valve better, which provides the calculation basis for compensating the additional load on the valve plug and improve the reliability of the control valve.

The paper report describes the simulation of the load governing system of steam turbine. The turbine governing system is vital for the safety and availability of a power plant. It consists of a hydraulic governing in which there are servo valve components. The dynamic characteristics of this system are nonlinear and difficult to predict. The paper report presents mathematical modeling, parameter determination, model validation, simulation and optimization of control valve action of the high and intermediate pressure turbine, speeder gear and throttle governing. The model takes into account flow force effect such as spring rate, viscous damping coefficient and compressibility of oil. The proposed model is simulated using Simulink package in MATLAB. The system has been optimized by using MATLAB. The input parameters for the simulator are load reference, main steam pressure and temperature, condenser pressure, extraction temperatures and governing mode selection nozzle/throttle/hydraulic. The output of the simulation is actual load response, secondary oil pressure, control valve displacement, etc. Governing simulator is useful for better understanding of the governing system, and it can be used as a training simulator.

The existing two systems of steam distribution in steam turbines - throttle and nozzle significantly affect the efficiency of high-pressure cylinders of powerful power turbines. When the turbine industry operates under conditions of varying steam consumption, the advantages, as well as when the turbo generation is in operation under conditions of the regime, has an absolute advantage on the side of the nozzle steam distribution. However, in modern steam turbines, the constructive implementation of concomitant steam distribution in order to ensure the need for the flow path of the turbine with the help of special control stages necessary for settling a chamber with an adjustable height. It has been shown that a chamber with an adjustable stage operates with very low efficiency at reduced loads. What is, in fact, with the existing design of coupled steam distribution, the process of the main throttling of steam was transferred from the area of control valves in the controlled stage of the turbine. As a result, the real advantage of concomitant steam distribution (as follows from recent publications) begins only when the steam flow through the turbine is reduced by 30-35%, which is an advantage with the HPC efficiency relative to throttling steam distribution when the load is reduced by 50%, and not by 3-5 % with a general decrease in HPC efficiency by 15-20%. A number of measures to improve the adjustable stages and leveling the velocity fields in the chamber of the adjustable stage did not lead to serious changes in the existing situation. In this regard, a fundamentally different constructive implementation of coupled steam distribution, providing for the creation of an autonomous (connected to the turbine only pipeline) valve block with a bypass chamber adjacent. As a result, it was possible to eliminate almost all the disadvantages of the accompanying steam distribution and to increase the efficiency for the design mode by 2-4% and increase this indicator by 10-12% while reducing the turbine load by 50%.

A 3D virtual system for the calibration of control valves is presented, the design is made based on the PI for the creation of the virtual environment, animations and interactions Unity 3D software is used, also a flowchart of the calibration of the control valve is created. The developed environment provides a simulation with a high level of realism due to the integration of HTC vive glasses, as well as efficiently allows training in control valve calibration.

The paper deals with a flow in control valves of steam turbines and in classical diffusers. The effect of the cone lift and the change of the flow cross-section on the energy losses is investigated. Total loss coefficients for a valve with a strainer and a valve without a strainer are evaluated along with the losses for the operating characteristics of the turbine. The effect of a flow dissipation and a disordered unsteady velocity flow field in the valve on the increase in the loss coefficient for a given angle of diffuser opening is considered.

Jaderná elektrárna zahrnuje také sekundární cyklus, jehož hlavní složkou je parní turbína. Parní turbína zpracovává tepelnou a tlakovou energii páry a přeměňuje ji na mechanickou energii. Spolehlivý a bezpečný provoz parní turbíny, tedy celého bloku, zajišťují ventily. V tomto článku je zkoumán tok páry regulačních ventilů, kde pára proudí ventilovou komorou kolem prvního ventilu k druhému ventilu. Byly vyhodnoceny experimentálně stanovené průtokové charakteristiky obou ventilů a výsledky byly zobecněny. Pokusy byly prováděny v aerodynamické laboratoři Ústavu termomechaniky AV ČR v Novém Kninu, kde bylo možné použít aerodynamický tunel pro vysoké rychlosti. Byly vyhodnoceny údaje o distribuci tlaků na vybraných místech. Energetická ztráta ve ventilech byla porovnána se ztrátou v samostatném difuzoru s různým stupněm expanze. Zkoumán byl také vliv sítka ventilu, což je část umístěná před kuželem regulačního ventilu. Bylo zjištěno, v jakém případě a kde dochází k významnému narušení pole rychlostního toku. První ventil v komoře je citlivější na tlakové ztráty na rozdíl od druhého ventilu, který je srovnatelný s ideální konstrukcí difuzoru, což naznačuje, že tato část sestavy ventilu je optimální. Pokud jde o filtry, bylo zjištěno, že filtr pomáhá vyrovnat poměry rychlosti na vstupu do ventilu, což má pozitivní vliv na snížení ztráty celkového energetického tlaku. Výsledkem je, že ztráta v prvním ventilu může být významně snížena, což pomáhá zvýšit účinnost celé turbíny. A nuclear power plant also includes a secondary cycle, which main component is a steam turbine. The steam turbine processes the thermal and pressure energy of steam and converts it into mechanical energy. Reliable and safe operation of the steam turbine, thus of the entire block, is ensured by valves. The flow in a pair of control valves, where the steam flows through the valve chamber past the first valve to the second valve, is investigated in this paper. The experimentally determined flow characteristics of both valves were evaluated and results were generalized. The experiments were carried out in the Aerodynamic laboratory of the Institute of Thermomechanics of the Czech Academy of Sciences in Novy Knin where a wind tunnel for high speeds could be used. Data of the distribution of pressures in selected places were evaluated. The energy loss in the valves was compared with the loss in a separate diffuser with varying degrees of expansion. The influence of a valve strainer, which is a part situated upstream of the control valve cone, was also investigated. It was found out in which case and where there is a significant disturbance of the velocity flow field. The first valve in the chamber is more sensitive to pressure losses in contrast to the second valve which is comparable to an ideal design of the diffuser, which indicates that this part of the valve assembly is optimal. Regarding the strainers, it was found out that the strainer helps to balance the velocity ratios at the inlet to the valve which has a positive effect on reducing the total energy pressure loss. As a result, the loss in the first valve can be significantly reduced which helps to increase the efficiency of the whole turbine.

Hydrostatic transmission (HST) system is widely used in the Heavy Earth Moving Machineries (HEMM). The hydro-motor used in the HST system provides the rotary motion for their traction, swing or other functions used in HEMM catering to different load profiles. This causes continuous variation in speed of the hydro-motor which reduces the efficiency of the HST system. Hence, controlling the speed of the hydro-motor is very much indeed. Constant speed of the hydro-motor can be achieved by controlling the input flow of it. Input flow can be controlled by controlling the displacement of the variable displacement hydraulic pump or by varying the flow through a proportional directional control valve (PDCV). The main objective of this research work is to design the PID controller which regulates the input flow to the hydro-motor so that the speed of the hydro-motor remains constant irrespective of the varying external load. To increase the PID controller performance, fuzzy control algorithm has been employed using MATLAB/Simulink environment. The main function of the fuzzy controller is to online tune the PID parameters which increase the performance of the drive. Comparison has been drawn based on the results obtained using Fuzzy-PID controller to the simple PID controller. The results show that Fuzzy tuned PID controller provides minimum settling time and less overshoot when compared to simple PID controller.

The high-pressure control valve of Weifang power generation Co. LTD unit one turbine happens to jitter during operation, especially in the low opening action, the jitter is more frequent. This situation is serious for the safety and stability of generating unit. This paper analyzes the cause of the high-pressure control valve jitter and formulates effective reconstruction plans. After the reform of the high-pressure control valve, it can maintain stable and normal regulation to ensure the safety and stability of the generating unit.

For safety-critical industrial applications, severe-service valves are often used, and the conditions during operations can be either single phase or multiphase. The design requirements for valves handling multiphase flows can be very different to the single-phase flow and depend on the flow regime within valves. The variation in flow conditions during the operation of such valves can have a significant effect on performance, particularly in oil and gas applications where multiphase behaviour can rapidly change within the valve causing unwanted flow conditions. Current practices in designing and sizing such valves are based solely on global phase properties such as pressure drop of the bulk fluid across the valve and overall phase ratio. These do not take into account local flow conditions, as with multiphase fluids, the flow behaviour across the valve becomes more complex. In this work, a well-validated computational fluid dynamics (CFD) model is used to locally and globally quantify the performance characteristics of a severe service valve handling multiphase gas and liquid flow. Such flows are frequently encountered in process equipment found in vital energy industries e.g. process and oil & gas. The CFD model was globally validated with benchmark experiments. Two valve opening positions of 60% and 100% were considered each with 5, 10, and 15% inlet air volume fractions to simulate real life conditions. The results show that while the non-uniformity in pressure field is along expected lines, there is severe non-uniformity in the local air, water and void fraction distributions within the valve trim. To quantify the phase non-uniformities observed, an equation for the distribution parameter was defined and used to calculate its value in each localised quarter within the trim. Phase velocity and void fraction data extracted from the CFD results were also used to obtain relationships for the local void fraction distribution and flow coefficient. The detailed investigation that has been carried out allows for local flow characteristics to be determined and embedded in sizing methodology for severe-service control valve systems with multiphase gas and liquid flow.

In this paper, a Matlab based GUI and Propotinal Integral Dervative (PID) controller is designed to automatically regulate the flow-rate of the circulating fluid. When fluids are transported over long distances, the pressure and flow rate have to be monitored remotely in a control room. Using an HMI or Control Panels the flow rate can be increased or decreased to compensate for pressure drops or disturbances. This paper attempts to demonstrate such an Industrial Control Operation in a scaled-down environment. A Graphical User Interface or GUI is constructed which enables the Operator to monitor, as well as control an electronically actuated Control Valve which can efficiently regulate the flow-rate. Automatic operations have also been implemented using a PID controller algorithm, which tries to track the Set-point in Real-time.

In this chapter, the airflow control scheme for output power control of the OWC plant is presented. The control valves are used to regulate the airflow inside the OWC chamber. Several studies have discussed the airflow control techniques in the past three decades, e.g. Falcao and Justino (1999a), Falcao et al. (2003, 2010a), Amundarain et al. (2010b, 2011c), Alberdi et al. (2011a, b), Mishra et al. (2015). However, the anti-windup type PID and FOPID controllers are very simple to design and very effective in terms of OWC performance. Therefore, anti-windup PID and FOPID controllers have been designed with manual as well as optimal tuning approaches.

Cavitation is a common problem in pumps, control valves and orifices; causing serious wear, tear and damages. Under the wrong condition, cavitation reduces the components lifetime drastically. Cavitation occurs when local static pressure in a fluid reaches a level below the vapour pressure of the liquid at actual temperature. This work aims to study the cavitating flow through a circular orifice using computational fluid dynamics and to find out optimum shape of orifice in terms of entrance roundness to minimize cavitation. Fluid model of sharp-edged circular orifice is created in CFD, and the obtained result is compared with that of available experimental result. After calibration and validation, the fluid models created for circular orifice is modified for different entrance roundness values. The influence of entrance roundness on cavitation characteristics is analysed and the optimum value of entrance roundness for minimizing cavitation is obtained.

Reliability assessment is an important component and tool used for process plants since the facility consists of many loops and instruments attached and operates based on each other availability, thus it requires a statistical method to visualize the reliability. The paper focuses on reliability assessment and prediction based on available statistical models such as normal, log-normal, exponential, and Weibull distribution. This paper also visualizes, which model fits best for assessment and prediction and also considers failure modes caused during a simulation mode process control operation. A simulation model is designed in this paper to observe the failure of the control valve causing stiction to visualize the failure modes and predict the best-fit model for reliability assessment.

One key component in the heat-using facility of district heating systems is the differential pressure control valve. This valve ensures a stable flow of water to the heat exchanger and the temperature control valve. It also makes a stable pressure difference between the supply and return lines. Hence, its malfunctioning could cause significant heat losses and, consequently, economic losses. To avoid this, it is necessary to monitor the abnormal operation of the valve in real-time. Despite various machine learning-based anomaly detection models, their decision is limited in practical use unless the rationale for the decision is appropriately explained. In this paper, we propose a Shapley additive explanation-based explainable anomaly detection scheme that can present the degree of contribution of input variables to the derived result. We report some of the experimental results.

A calculated-experimental analysis of the opportunity of getting the boot-shaped front edge of the injection rate (boot injection) was performed. The research was carried out with Common Rail injectors (CRI) of the most widely used designs: CRI No 1 distinguished by its control valve with locking cone and valve piston; CRI No 2 with its fuel pressure balanced control valve, a channel in the piston and increased internal volume; CRI NO 3 distinguished by its control valve having a flat latch and needle valve which is not closing the fuel drain hole when it is in the highest position; CRI No 4 with partial closing of the control fuel drain hole. It was demonstrated that friction in the couple: control valve piston - guiding surface of the CRI No 1 hampers realization of the boot-shaped front edge of the injection rate due to its smoothening. The CRI No 2 enables to get the boot-shaped injection rate only in case of small pressures in the common rail (pcr ≤ 50 MPa). This is explained by particular features of its control valve design. The CRIs No 3 and 4 ensure the boot-shaped injection rate at various pressures in the common rail. It was shown by the example of the CRI No 4 that instability in case of a boot-shape injection rate is comparable with instability of the primary fuel injection which is widely used for the organization of working processes of diesel engines having Common Rail type fuel systems.

Hydraulic systems are widely used in drive and control systems of multiple devices. Various types of control valves are used to determine the appropriate direction of the working fluid movement. This article provides flow analysis of a two-way hydraulic control valve in a cartridge housing. The flow rate through the valve is controlled by a spring and an electromagnet. Design of a poppet ensures tightness in both directions in the cut-off position. Accordingly, there is no need to use additional shut-off valves. However, the fluid stream entering the valve is divided into several jets, due to the cartridge design. This makes the flow complex and difficult to be modelled. Therefore, the advanced ANSYS/Fluent software was used to carry out the analysis. The conducted tests allowed the influence of selected geometrical and physical parameters on the valve characteristics to be examined.

In this paper a prototype of a flow control valve is described and numerically simulated. The flow control valve is used in hydraulic systems to maintain constant fluid flow despite changing loads of a receiver. The standard construction of this type of valves is modified mainly by eliminating the spring. The prototype consists the hydrostatically unloaded throttle valve and pressure ratio valve substituting pressure difference valve. The article concentrates on numerical simulation conducted for different positions of pressure ratio valve’s spool and various throttle valve settings. Additionally the rotation of the spool is included in simulation and its influence on valve’s characteristics is evaluated. The article also describes the methodology of determining flow characteristics of control valve. Results from numerical simulation are compared to results of experimental research.