Automatic Control Valves Research Articles

Perencanaan Control Valve Pada Head Tank PLTA Tulungagung Menggunakan PLC

Head Tank of the Tulungagung Hydro Electric Power Plan of PT PJBUP Brantas still has a manual control valve which consists of a gate valve and a pair of float valves. There are some problems when the pipe of the float valve is blocked by cediment and debris, it could affect the cooling water system and make damage to the power plant. In this research, there would build a plan of the automatic control valve of the Tulungagung HEPP. PLC Siemens Simatic Step 7 was used as a control base on a SCADA software Wonderware Intouch version 10.0.0. In this modification plan, a pair of float valve changed over solenoid valve and manual gate valve change over motorized valve. For the water level that would be ultrasonic sensor SICK UM 30 as a input for the power meter Omron Procces Meter K3MA-J. The reliability of this modification are excellence and complete for the auto/manual control even for the long distance one. Moreover this modification also has excellence safety.

Automatic Flow Control Valves Solve Raw Water Management Challenges

For all the historical and natural charm of Greenville, S.C., efforts to serve the city's water customers were hampered by raw water management challenges at a nearby reservoir. A new automatic flow control valve provided Greenville Water, City of Greenville Commission of Public Works, with a customized solution.

Influence of Pipeline Operating Pressure on Value Setting of Automatic Control Valves at Different Pressure Drop Rates

When a natural gas pipeline ruptures, the adjacent upstream and downstream automatic control valves (ACV) should close quickly to prevent leakage or explosion. The differential pressure set point (DPS) at each valve location is the main criteria for value setting in ACV actions. If the DPS is not properly adjusted, the ACV may mistakenly close or it may not take any actions at a proper time. In this study, the effect of characteristic parameters such as pipeline operational pressure (POP) and pipeline pressure drop rate (ROD) due to rupture or a major leak was experimentally investigated on DPS. 25 different conditions with the double set of the mentioned typical characteristic parameters were chosen. In each condition, the differential pressure (DP) was measured over a period of 180 s by statistically analyzing the experimental results, so 25 maximum DP values (DPSs) were obtained. The DPS rises by an increase in ROD or a decrease in POP. Because of using nitrogen gas instead of natural gas for safety reasons and the uncertainties, the DPS results can be practically applied by adding a safety factor of 15%. Finally, the diagram of DPS with respect to ROD and that of non-dimensional DPS (DOP) versus non-dimensional ROD (RTP) were provided for different POP’s.

A Numerical Simulation for the Determination of the Shunt Ratio at a T-Junction With Different Branch Angles, Viscosities, and Flow Rates

T-junctions have been applied in water-control structures. A comprehensive understanding of shunt characteristics can contribute to the optimal design of T-junctions. In this work, we seek to understand the shunt ratio of fluids with different viscosities in a T-junction and to achieve a greater shunt ratio. The computational fluid dynamics (CFD) approach is applied to study the influence of the properties, such as the fluid viscosity, the branch angle, the channel shape, and the flow rate, on the shunt ratio in a T-junction. The viscosity of oil can be divided into three intervals, and the optimal angles of the T-junction are different in each interval. For the fluid viscosity in the 1–20 cP range, the optimal branch angle is in the 45–60 deg range. For the fluid viscosity in the 20–65 cP range, the branch angle should be designed to be 45 deg. For the viscosity greater than 65 cP, the branch angle should be designed to be 75 deg. The appearance of the eddy and secondary flow will reduce the flow. The secondary flow and eddy intensity on the branch increase with increasing angle. The secondary flow intensity of the main channel decreases gradually with the increase in the angle. This study provides an important guidance for the design of automatic water control valve tools.

Safety Analysis and Fault Automatic Recognition Technology of Regenerative Adsorption Dryer

In oil and gas processing station, the regenerative adsorption dryer absorbs the compressed air moisture to ensure the dew point of the gas. Once the dryer fails, it will cause the water dew point to rise, which will affect the operation parameters of the device in winter when the automatic control valves freeze. Control valves freezing can lead to serious consequences such as release, gas-Migration, and unqualified product quality and so on, which are difficult to deal with. The pressure of dryer and regenerative pressure are characterized by a certain periodic change when dryer is working. This paper introduces the automatic identification technology of the dryer fault. Logic analysis through DCS system can identify faults by analyzing the time curve of regenerative pressure, catching abnormal changes of the curve during the failure of dryer. The automatic identification technology of the dryer fault will be achieved in a short time and send out alarm signal to ensure the safe operation of the oil and gas treatment station. It is highly valuable for wide extension and application.

Experimental values for adjusting an automatic control valve in gas pipeline transportation

When a natural gas pipeline ruptures, the adjacent automatic line control valves (ALCVs) should close quickly to prevent leakage or explosion. The differential pressure set point (DPS) at each valve location is the main criteria for value setting in ALCV action. If the DPS is not properly adjusted, the ALCV may mistakenly close or it may not take any action at proper time. This study focused on the DPS values prediction for setting ALCV installed on a gas pipeline with 1mm orifice diameter. The effect of characteristic parameters such as pipeline operational pressure (POP) and pipeline pressure drop rate (ROD) due to rupture or major leak was experimentally investigated on DPS. Twenty-five different conditions with double set of typical mentioned characteristic parameters were chosen. For each condition, the differential pressure (DP) was measured over 180 seconds by analyzing the experimental values. Therefore, 25 maximum DP values (DPSs) were obtained. The DPS increases by increase in ROD or decreasing POP parameters. Because of using nitrogen gas instead of natural gas due to safety reasons, the DPS results can be practically applied by adding a safety factor of 15%. The diagram of DPS with respect to ROD and non-dimensional DPS (DOP) versus non-dimensional ROD (RTP) was provided for different POPs.

An experimental study of the effective parameters on automatic line-break control valves action in natural gas pipelines

The automatic line-break control valve (LBV) is a robust self-contained pipeline monitoring system which is widely used to prevent gas releasing upon rupture or large leakage event in the oil and gas pipelines. The differential pressure set point (DPS) at each valve location is the main criteria for value setting in LBV action. If the DPS is not properly adjusted, the LBV may mistakenly close or it may not take any action at proper time. In this study, the effect of characteristic parameters such as orifice diameter (OD), pipeline operational pressure (POP) and pipeline pressure drop rate (ROD) due to rupture or major leak was experimentally investigated on DPS. 100 different conditions with triple set of typical mentioned characteristic parameters were chosen. For each condition, the differential pressure (DP) was measured over 180 s by statistically analyzing the experimental results. Therefore, 100 maximum DP values (DPSs) were obtained. The attainable time to DPS depends only on OD and is independent of the POP and ROD and decreases by increasing the OD. The DPS increases by increase in ROD or decreasing OD or POP parameters. Because of using nitrogen gas instead of natural gas due to safety reasons and the uncertainties, the DPS results can be practically applied by adding a safety factor of 10%–15%. Finally, the diagram of DPS with respect to ROD was provided for different POPs and ODs. The diagram can be used as a basis for designing and regulating of LBVs installed on gas transportation pipelines.

Water loss cut with automatic control valves

Melaka is a small state on the Malay Peninsula. In 2008, the authorities decided to upgrade its water infrastructure to reduce Non-Revenue Water loss. The local water company turned to a manufacturer of automatic control valves for the global water industry.

Reliable water with automatic control valves

The city of Abha, in south west Saudi Arabia, has a new reservoir on top of a hill which releases water down to a main reservoir 6 km away. Problems with dangerous pressure differentials threatened to disrupt the water supply until a Canadian manufacturer of automatic control valves came up with a solution.

Value setting for the rate of pressure drop of automatic line-break control valves in natural gas pipelines

Automatic line-break control valves are widely used to prevent the release of gas in the event of a rupture in natural gas pipelines. The rate of pressure drop (ROD) set point at each valve location is a critical parameter that determines whether or not the valve closes, and this value must be measured over a period of time. If the ROD set point is not appropriate, the automatic line-break control valve may mistakenly shut down or not take timely action. In this study 12 typical natural gas pipeline systems in China were analyzed to evaluate the ROD set point problem, which is associated with automatic line-break control valves. Transient analysis hydraulic software was used to determine the appropriate ROD set point for automatic line-break control valves by simulating 891 different pipeline-rupture conditions and 256 valve-closing conditions. The maximum ROD value over 120 s for each condition was obtained by statistically analyzing the simulation results. Each valve-closing condition was affected by the operating pressure and the gas velocity. As the gas velocity or the operating pressure increased, the maximum ROD value also increased. ROD set points for 12 different gas pipelines have been recommended based on the following principles: the upstream valve shutdown should not sequentially cause a downstream valve shutdown, and the maximum ROD value is over 120 s of the various valve-closing conditions. The value-setting method developed in this study can be applied to other gas pipelines.

Neuro-fuzzy-based hybrid controller for stable temperature of liquid in heat exchanger

The liquid heating system is a temperature sustaining system which used to preserve the liquid temperature at a constant value at different temperature ranges. In this paper, neuro-fuzzy controller (NFC)-based control technique is proposed for achieving the desired liquid temperature. NFC is the combination of neural network (NN)-based controller and fuzzy logic controller (FLC). Initially, the error temperature and change of error temperature of a liquid heating system are determined. Then, the temperature variation is applied separately to FLC and NN-based controller. From the output of FLC and NN-based controller, the mean liquid temperature ratio of the condenser is calculated. Then based on the liquid temperature ratio, the automatic control valve (ACV) is adjusted till the desired temperature is reached. The proposed system is modelled in simulation platform and the output performances are evaluated. Then, the temperature stabilising performance of proposed controller is compared with FLC and ANN.

The Study of Hydraulic Valve Position Control Based on PLC Controller

With the growing shortage of water today, in order to control the flow of pipe conveyance, it is essential for further study of automatic control valves, especially the automatic control technology of control valve. In this paper, by using programmable control and signal transmission technologies etc. a prototype model of hydraulic valve position control is constructed. Prototype model is designed as the closed-loop of position control system, by using high-precision angular displacement sensor detecting the position of the valve plate, converting the output signal of sensor into an industrial process signal 4-20mA with the low-drift transmitter chip XTR101, and with modular PLC as system control center, using three-phase inverter controlling the steering and speed of motor and cooperating with closed pump control system for hydraulic drive, it achieves the closed-loop control hydraulic valve position. This paper provides some technical support for the better use of water resources.

Pressure measurements with valve-induced transient flow in water pipelines

Pressure measurements provide valuable insights for managing water supply systems by tracking time-dependent hydraulic transients. In this study, we report on two pressure-monitoring issues – sampling location and sampling interval – by analyzing a valve-induced transient event that was not recorded in the 1-min timestamp pressure generated by the existing supervisory control and data acquisition (SCADA) system of a real water transmission line in the southern part of Korea. Field measurement data show that the measured pressure magnitude is influenced by the sampling location, which depends on pipe connectivity and distance from automatic control valve, and by the sampling interval, which is sensitive to network size for wave propagation. Based on the findings of the field experiments, a pressure-measurement method is proposed by employing numerical transient simulation and spectral analysis of pressure waves.

반도체 약액용 자동제어 플라스틱 밸브의 내부 유동해석

Diaphragm type noncontact automatic control valve is a valve for controling acidic PR(Photo Resist) liquid used in the semiconductor process. PR is photosensitive liquid that changes phases depending on light transmittance. PR is very toxic and expensive; the purpose of this paper is to address methods that prevent loss due to leaks. The design of noncontact precise automatic control valve is expected to play an important role in controlling fluid flow, therefore influencing energy conservation and environmental improvement. In this paper, diaphragm type automatic control valve's part design, assembly and simulation are introduced. Also, through the analysis of fluid flow the valve's internal velocity, pressure, and turbulent intensity are interpreted. This paper proposes to contribute to the improvement of the valve's performance.

Design of Hydraulic Dynamic Equilibrium in Household Heating System

The operating mode of large flow quantity and small temperature difference is used in the traditional serial heating system, which results in a serious problem of hydraulic misadjustment, leading to visible temperature difference among different rooms. In this paper, in order to realize the hydraulic dynamic equilibrium of heating system and control of household heating, the automatic flow control valves are used for the control of flow rate. On the basis of theory analysis of hydraulic misadjustment, the results show that: the efficiency of heating system and control of household heating can be improved significantly, as well as the energy saving up to 20%.

自动流量平衡阀过流曲线激光切割工艺

自动流量平衡阀过流曲线激光切割工艺

Learning control for batch thermal sterilization of canned foods

A control technique based on Reinforcement Learning is proposed for the thermal sterilization of canned foods. The proposed controller has the objective of ensuring a given degree of sterilization during Heating (by providing a minimum temperature inside the cans during a given time) and then a smooth Cooling, avoiding sudden pressure variations. For this, three automatic control valves are manipulated by the controller: a valve that regulates the admission of steam during Heating, and a valve that regulate the admission of air, together with a bleeder valve, during Cooling. As dynamical models of this kind of processes are too complex and involve many uncertainties, controllers based on learning are proposed. Thus, based on the control objectives and the constraints on input and output variables, the proposed controllers learn the most adequate control actions by looking up a certain matrix that contains the state-action mapping, starting from a preselected state-action space. This state-action matrix is constantly updated based on the performance obtained with the applied control actions. Experimental results at laboratory scale show the advantages of the proposed technique for this kind of processes.

安全弁による低圧化システムの圧力制御対策(III) : 自動減圧弁を直列設置した場合

安全弁による低圧化システムの圧力制御対策(III) : 自動減圧弁を直列設置した場合

Simultaneous Heating and Cooling—The HVAC Blight

ABSTRACT Despite the good intentions of energy codes that restrict or prohibit it, simultaneous heating and cooling occurs too frequently in HVAC systems and represents a large opportunity for reduced energy use. Like driving with the brakes on but with no smell, it is a silent consumer of energy, so simple that it is often overlooked. In air handlers, the waste of heat-cool overlap can occur within a few feet of each other. In systems with primary and terminal level temperature control, the lack of coordination between control settings creates similar waste, but in a less obvious way. Automatic control valves “told to close” don't always comply. Certain automatic control routines, even with DDC controls, can allow overlap on a transient or continuous basis. Ironically, the most simplistic HVAC systems are often the most immune. A few systems require overlap to accomplish a specific function, such as humidity control, but for many systems the expenditure of energy goes on with no benefit and is an obvious energy waste. Using experience from hundreds of working HVAC systems, this article will point out common causes of unintentional heating and cooling overlap, how to spot them, how to correct them, and provide tips on quantifying the savings.

Water Supply System Performance for Different Pipe Materials Part II: Sensitivity Analysis to Pressure Variation

In water supply systems there are many situations during normal operation that induce the occurrence of pressure transients, where high pressures are followed by low, sometimes even negative pressures. These transients may cause ruptures in pipes creating thus leaks or opportunities for contaminants to enter the water supply system. Thus severe pressures transients should be avoided or adequately controlled in potable drinking systems. The level of service provided by water distribution systems is an important matter in the water industry of today. However, the measure of the performance of a pipe system network is not a straightforward task. In this study the performance of pressures in two networks (a cast iron network and a polyethylene network) with the same typology was compared. The transient state conditions were induced by different typical hydromechanical devices operation characterised by a sudden pumps trip-off, a leakage occurrence and a closure of an automatic control valve. For the hydraulic simulations, advanced models based on numerical computation for steady and transient state conditions were used. A performance evaluation model was developed to analyse each type of situation since the simulation time period and the concerns regarding the system behaviour can be fairly different.