scholarly journals Valve Location Method for Evaluating Drain Efficiency in Water Transmission Pipelines

Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2759
Author(s):  
Byoung-Ho Shin ◽  
Doo Yong Choi ◽  
Kwansue Jung ◽  
Zong Woo Geem

Water transmission pipelines, which transport bulk water into storage facilities, usually have a tree-type configuration with large dimensions; thus, the breakage of a pipeline may cause a catastrophic service interruption to customers. Although drain efficiency is closely related to the number of washout and control valves and their locations, there is no useful guideline. This paper proposes a valve locating method by introducing numerical analyses to enumerate drainage time and zone. A time integration method, combined with the Newton–Raphson algorithm, is suggested to resolve drainage time, while considering the friction loss in gravitational flow. A drain direction matrix, which shows drain direction and coverage, is derived using a network searching algorithm. Furthermore, a feasible practical approach is presented by introducing a critical horizontal slope, a major washout valve, drainage indices, and control valve embedment. The developed method is first applied to simple pipes to validate the drainage time module. Subsequently, the model is expanded to the CY transmission line, which is one of the BR water supply systems in South Korea currently in operation. The results reveal that three drain valve locations have been neglected, and the addition of control valves guarantees consistent drain time below the operational criteria.

Author(s):  
Jinyuan Shi ◽  
Yong Wang ◽  
Xiaoping Zhong ◽  
Zhicheng Deng

A method for the reliability and the availability prediction of main stop valve and control valve systems of steam turbines is presented. The calculation models for the reliability and the availability of series, parallel and series-parallel systems of main stop valves and control valves are introduced. The reliability block diagrams, the availability block diagrams, formulas for the reliability prediction and the availability prediction of systems with 2 main stop valves and 2 control valves, 2 main stop valves and 4 control valves, 2 main stop valves and 6 control valves, 4 main stop valves and 4 control valves are given together with some examples. The mathematical model for the reliability and the availability prediction method of main stop valve and control valve systems of steam turbine is simple and the physical meaning is definite. The reliability and availability of main stop valve and control valve systems can be quantitatively already calculated and improved during the design stage. A basis is thus provided for the reliability and the availability design of main stop valve and control valve systems of steam turbines.


2021 ◽  
pp. 1-16
Author(s):  
Trygve Husveg ◽  
Rune Husveg ◽  
Niels van Teeffelen ◽  
Robert Verwey ◽  
Peter Guinee

Summary In hydrocarbon production and processing, choke and control valves mix and emulsify petroleum phases. The consequence is often that the efficiency of separation processes is affected and finally that the quality of oil and water phases is degraded. Over the last few years, low-shear valves targeting petroleum processes have emerged on the market. This paper presents four separate live-fluid experiences from low-shear valve installations, each surveyed and documented by an independent third party. Three of the installations refer to choke valves, whereas the fourth installation refers to a control valve. For each installation, standard choke and control valves were used as reference valves. In terms of downstream separation efficiency, the low-shear choke valves reduced oil-in-water concentrations respectively by 70, 45, and 60%, by total average. In the control valve application, the low-shear valve, which was located between the hydrocyclones and a compact flotation unit, reduced the oil-in-water concentration by 23%. In sum, the field installations have demonstrated that low-shear valves significantly and consistently reduce oil-in-water concentrations and thus improve the produced water quality. The results signify that low-shear valves may be used in debottlenecking separation and produced water treatment processes, reducing the environmental influence from produced water discharges. Because the low-shear technology enables processing of petroleum phases with less effort, energy, and chemicals, it also reduces emissions to air.


Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 461
Author(s):  
Weixiang Ni ◽  
Jian Zhang ◽  
Sheng Chen

In the long-distance and high-drop gravitational water supply systems, the water level difference between the upstream and downstream is large. Thus, it is necessary to ensure energy dissipation and pressure head reduction to reduce the pipeline pressure head. The energy dissipation box is a new type of energy dissipation and pressure head reduction device, which is widely used in the gravitational flow transition systems. At present, there is still a dearth of systematic knowledge about the performance of energy dissipation boxes. In this paper, a relationship between the location of the energy dissipation box and the pressure head amplitude is established, a theoretical optimal location equation of the energy dissipation box is derived, and numerical simulations using an engineering example are carried out for verification. The protective effects of an energy dissipation box placed at the theoretical optimal location and an upstream location are compared. The results indicate that for the same valve action time, the optimal position allows effectively reducing the total volume of energy dissipation box. The oscillation amplitudes of the water level in the box and the pressure head behind the box are markedly reduced. Under the condition that the water level oscillation of the energy dissipation box is almost the same, the optimal location offers better pressure head reduction protection performance than the upstream location.


2014 ◽  
Vol 630 ◽  
pp. 375-382 ◽  
Author(s):  
Daniel Himr ◽  
Vladimir Haban

A pumping station in a fuel storage suffered from pressure pulsations in a petrodiesel pipeline. Check valves protecting the station against back flow made a big noise when disc hit a seat. Due to employees complaints we were asked to solve the problem, which could lead to serious mechanical problems. Pressure measurement in the pipeline showed great pulsations, which were caused by self-excited oscillation of control valves at the downstream end of pipeline. The operating measurement did not catch it because of too low sampling frequency. One dimensional numerical model of the whole hydraulic system was carried out. The model consisted of check valve, pipeline and control valve, which could oscillate, so it was possible to simulate the unsteady flow. When the model was validated, a vessel with nitrogen was added to attenuate pressure pulsations. According to the results of numerical simulation, the vessel was installed on the location. Subsequent measurement proved noticeably lower pulsations and almost no noise.


1993 ◽  
Vol 115 (3) ◽  
pp. 571-575 ◽  
Author(s):  
J. Lieh

A passenger car model with a full car body and four wheel-axle assemblies is used to investigate the influence of semiactive suspensions on ride performance. Mean square values are evaluated for various damping levels and control valve switching times. Due to severe nonlinearities, frequency responses are not obtained directly. They are reconstructed from Fast Fourier Transform (FFT) using a Hanning window. The results are compared with those from LQR active suspensions and pure on-off dampers. The effect of control valve switching time (bandwidth) is studied and shows a significant influence on the vehicle ride, suspension travels, and tire deflections.


2021 ◽  
Author(s):  
Mohammed Eltayb

Fault tolerant control (FTC) is essential nowadays in the automation industry. It provides a means for higher equipment availability. Fault in dynamical systems can occur due to the deviation of the system parameters from the normal operating range. Alternatively, it can be a structural change from the normal situation of continuous operation such as the blocking of an actuator due to the mechanical stiction. In this research project, a fault tolerant controller is designed with Matlab Simulink for a feedwater system. The feedwater system components are modified to work under embedded controller design with FTC attached to it. Feedwater systems usually consist of a de-aerator or simply a water storage tank, feedwater pumps, control valves, piping and support fitting elements such as chock valves, anges, hoses and relief valves, beside instrumentation devices like level transmitters, flow transmitters, pressure regulators. The faults are injected separately for each device. Fault diagnostic is used to detect and identify the faults by Limit-checking method. Then a controller is reconfigured to take the action of correcting the hardware failures in the control valve, level sensor, and feedwater pump. The simulation results revealed that the redundant components can take over and handle the process operation when the fault occurs at the duty components. Level sensors are set to work in on-line mode, while the control valves are set to work in off-line mode, due to the mechanical parts movement. Setting the control valves in on-line mode reduces the probability of valve stiction and elongates the component availability. The results reveal the operation of feedwater system is not stopped when a hardware failure takes place in all feedwater system major components. Moreover, the disturbances are not considered in this research as there are many control techniques that can be used to handle the disturbance in a robust way.


2012 ◽  
Vol 619 ◽  
pp. 26-29
Author(s):  
Chao Sheng Song ◽  
Qi Ming Huang ◽  
Zhan Gao ◽  
Jie Xu

This paper introduces dynamic impact analysis as an effective technique for studying the response of horizontal vibrated conveyor with time-varying impact excitation by the falling of the scrap. A two degree-of-freedoms impact dynamic model is formulated considering the static and dynamic coulomb friction between the scrap and chute. Then the time integration algorithm was applied in the program to solve the dynamic equations. Using the proposed method, the impact effects of ideal single scrap and multiple scraps on the dynamic response of the conveyor were analyzed. Computational results reveal numerous interesting dynamic characteristics which can be used to forecast and control the vibration of the scrap and conveyor system.


2021 ◽  
Author(s):  
Andrea Pacini ◽  
Stefano Rossini

Abstract In the wake of Eni's strategy to curb fugitive emissions - in particular methane – an innovative control valve (Clarke Shutter Valve) has been deployed and tested in an Italian Eni facility. This shutter type valve is capable of reducing the fugitive emissions by more than 90%, as well as greatly curbing purchase costs, thanks to an innovative design in bonnet and regulating mechanism. In order to assess the real potentiality of the innovation, four Fisher globe valves and one Fisher V-ball were substituted with the Shutter Valves on different hydrocarbon streams of the Trecate facility (Piedmont), in particular on streams containing oil, gas and corrosive fluids. The valves were monitored for more than a year and fugitive emissions tests have been performed to detect and estimate methane leak rates. Since this represented a first deployment of this technology in Europe, a thorough analysis and technology validation of the valves has been performed. A successful installation and start-up were performed in 3 days by Eni's staff at in February of 2020. The valves were fully operational after the installation and to date no issues have been reported. In order to monitor the valves performances of flow control, continuous data collection on each valve has been implemented, and the analysis performed showed that all valves behave correctly as to Eni's standards. A fugitive emission test that has been performed at the end of 2020 with a certified portable FID/PID analyzer displayed that no methane emissions were detected from the valves. Lastly the one year and half long technology validation concluded that the Shutter Valves are a valid technology for curbing methane emissions from the Oil and Gas plants, and that suggested to qualify the company as Eni partner for control valves. This deployment and field tests, as well as the technological assessment performed by Eni's professionals showed the potentiality of this new type of valves in reducing the methane emissions from the petroleum industry. Understanding the potentiality of intrinsically carbon neutral technology is a crucial step for the mitigation of greenhouse gases emissions and towards the creation of a more environmentally friendly industry.


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