scholarly journals Reducing the Effects of Water Hammer Phenomenon in Pipelines by Changing the Closing Rate of Line Break Valve (LBV)

2021 ◽  
Author(s):  
Mohammad Reza Boroomand ◽  
◽  
Nasim Safar Razavizadeh ◽  
Ahmad Eshghi ◽  
◽  
...  
Keyword(s):  
Transmission Line ◽  
Initial Conditions ◽  
Saline Water ◽  
Flow Analysis ◽  
Flow Simulation ◽  
Environmental Hazards ◽  
Water Hammer ◽  
Air Chamber ◽  
Water Transmission ◽  
Closing Rate

Line break valves in pipelines are using to prevent environmental hazards caused by the entry of the fluid into the surrounding. The operation of these valves leads to sudden changes in pressure and velocity, resulting in the occurrence of the water hammer phenomenon. The water hammer pressure will cause serious problems such as the destruction of pipelines and transmission line equipment and tools. Due to the salinity of water, when a fracture occurs, the amount of water that enters the surrounding is environmentally essential, so the use of several LBVs is vital. This paper investigated a water transmission line with a total length of 337 km that transfers saline water from Khoor Moosa to Azadegan plain. This study discussed the closing of the valve at different rates and the solution to reduce its destructive effects. WaterGEMS V8i software and Hammer V8i software are respectively using to perform a steady flow simulation and damping flow analysis for this phenomenon. The results obtained from the steady-state flow simulation is the initial conditions in the damping flow calculations. Then, by reducing the closing rate of the valve in 6 different scenarios, the volume of air chambers decreased. Finally, the results led to creating a linear relationship between the valve closing rate and the capacity of the air chamber. The optimal model for this rate depends on reducing the construction cost as well as the environmental hazards caused by discharged water.

scholarly journals Pump-stoppage-induced water hammer in a long-distance pipe: a case from the Yellow River in China

2018 ◽  
Vol 19 (1) ◽  
pp. 216-221
Author(s):  
Yipeng Zhang ◽  
Meiqing Liu ◽  
Zhiyong Liu ◽  
Yuanwei Wu ◽  
Jie Mei ◽  
...  
Keyword(s):  
Transient Flow ◽  
Yellow River ◽  
Flow Analysis ◽  
Water Hammer ◽  
Extreme Condition ◽  
System Component ◽  
Long Distance ◽  
Pump Failure ◽  
Transient Flow Analysis ◽  
Water Transmission

Abstract Pump stoppage can instantaneously increase the pressure within a pipeline, which is an extreme condition and poses a severe threat to the safety of long-distance water transmission projects. Reducing positive and negative pressures is essential to reducing this risk, improving operational efficiency, and avoiding system component fatigue. This study investigated the performance of a combination of dimensionless pump parameters and pipeline pressure in providing detailed information for designing protective equipment to mitigate water hammer effects, which are generated by sudden pump stoppage. The conditions of the method of characteristics were satisfied by conducting an overall transient flow analysis to estimate the potential of the increased pressure relevant to all types of operating schemes. Extreme pressure waves, produced by pump failure or rapid valve closure, can be prevented using efficient protective designs. The findings of this study can be instructive to alleviating the potential damage engendered by water hammer.

scholarly journals Distributing Load Flow Computations Across System Operators Boundaries Using the Newton–Krylov–Schwarz Algorithm Implemented in PETSc

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2910
Author(s):  
Stefano Rinaldo  ◽  
Andrea Ceresoli  ◽  
Domenico Lahaye  ◽  
Marco Merlo  ◽  
Miloš  Cvetković ◽  
...  
Keyword(s):  
Power Flow ◽  
Flow Analysis ◽  
Flow Simulation ◽  
Load Flow ◽  
Inexact Newton Method ◽  
Test Case ◽  
Flow Solver ◽  
Cross Border ◽  
System Operator ◽  
Schwarz Algorithm

The upward trends in renewable energy penetration, cross-border flow volatility and electricity actors’ proliferation pose new challenges in the power system management. Electricity and market operators need to increase collaboration, also in terms of more frequent and detailed system analyses, so as to ensure adequate levels of quality and security of supply. This work proposes a novel distributed load flow solver enabling for better cross border flow analysis and fulfilling possible data ownership and confidentiality arrangements in place among the actors. The model exploits an Inexact Newton Method, the Newton–Krylov–Schwarz method, available in the portable, extensible toolkit for scientific computation (PETSc) libraries. A case-study illustrates a real application of the model for the TSO–TSO (transmission system operator) cross-border operation, analyzing the specific policy context and proposing a test case for a coordinated power flow simulation. The results show the feasibility of performing the distributed calculation remotely, keeping the overall simulation times only a few times slower than locally.

Flow Analysis of Spray Jet and Direct Jet Nozzle for Fire Water Monitor

2010 ◽  
Vol 139-141 ◽  
pp. 913-916 ◽  
Author(s):  
Guo Liang Hu ◽  
Wei Gang Chen ◽  
Zhi Gang Gao
Keyword(s):  
Flow Analysis ◽  
Flow Characteristics ◽  
Flow Simulation ◽  
Jet Flow ◽  
Extended Length ◽  
Jet Nozzle ◽  
Simulation Results ◽  
Steady Velocity ◽  
Nozzle Structure

In order to investigate the influence rules between the jet nozzle of fire water monitor and the jet performances, two typical jet nozzle, the spray jet and direct jet nozzle was designed to analysis the jet flow characteristics. Flow simulation of the jet nozzle was completed using fluent kits. The outlet velocity of the spray jet nozzle and direct jet nozzle were investigated in detail, and the influence rules of the nozzle structure on the outlet velocity was also discussed. The simulation results show that the steady velocity of the jet nozzle is about 34m/s that coinciding the contour magnitude, and the better extended length of the direct jet nozzle is about 50mm length that can improve the jet performances. The results can verify the reasonableness of the designed nozzle, it also can optimize the nozzle structure and increase the jet performance of the fire water monitor.

Potential for manganese biofouling in water transmission lines using model reactors

2018 ◽  
Vol 4 (6) ◽  
pp. 761-772 ◽  
Author(s):  
Nicole E. Allward ◽  
Brittany S. Gregory ◽  
Amina K. Sotddart ◽  
Graham A. Gagnon
Keyword(s):  
Water Supply ◽  
Transmission Line ◽  
Manganese Oxide ◽  
Transmission Lines ◽  
Water Transmission

Biologically mediated manganese oxide accumulation was observed in a water supply plant transmission line. A novel, putative manganese oxidizing bacterium,Candidatus Koribacter, was identified.

Effects of the Air Volume in the Air Chamber on the Performance of Water Hammer Pump System

2011 ◽  
Vol 4 (2) ◽  
pp. 255-261 ◽  
Author(s):  
Sumio Saito ◽  
Masaaki Takahashi ◽  
Yoshimi Nagata
Keyword(s):  
Water Hammer ◽  
Pump System ◽  
Air Volume ◽  
Air Chamber

Design Modification Investigation of a Concept Heat Exchanger for Better Efficiency through Thermal Simulation

2013 ◽  
Vol 631-632 ◽  
pp. 1026-1031
Author(s):  
Tousif Ahmed ◽  
Md. Abu Abrar ◽  
Md. Tanjin Amin
Keyword(s):  
Heat Exchanger ◽  
Heat Exchangers ◽  
Flow Analysis ◽  
Flow Simulation ◽  
Thermal Simulation ◽  
Attractive Alternative ◽  
Computational Domain ◽  
Thermal Flow ◽  
Design Modification ◽  
Compact Design

Thermal flow simulation can be used to study the fluid flow and heat transfer for a wide variety of engineering equipment. Flow simulations with the advent of computer architectures with superfast processing capabilities are rapidly emerging as an attractive alternative to conventional thermal flow analysis which is either too restrictive or expensive. In thermodynamic applications, increase of thermal efficiency of heat exchangers (i.e. radiators, cooling towers, condensers, intercoolers) is essential for compact design and improving whole cycle efficiency thus improving economic viability of the system. This paper outlines the process taken to optimize the geometry of conventional heat exchanger. Models were drawn into Solidworks and a computational domain was created. Solidworks Thermal Simulation was used to iterate toward a converged solution with the goal of obtaining a better efficiency of the heat exchanger. The results are analyzed and compared between two differently designed heat exchangers to find out the improvements. These practices were detailed in hopes that further research would use the ground work laid out in this paper to redesign existing heat exchangers.

Numerical Analysis of Pipeline Equipment Effect on Water Hammer Using Characteristic Method

2003 ◽  
Author(s):  
Mohammad R. Ansari ◽  
Abdolreza Davari
Keyword(s):  
Momentum Conservation ◽  
Water Hammer ◽  
Loss Coefficient ◽  
Maximum Pressure ◽  
Characteristic Method ◽  
Pump Impeller ◽  
Air Chamber ◽  
Large Pressure Gradient ◽  
Pipeline Equipment ◽  
The Moment

In this attempt effect of pipeline equipment behavior was considered on water hammer numerically. The effect includes opening / closing of the shut off valves, loss of coefficient of the outlet bypass pipe for the air chamber, elasticity of the pipeline and loss coefficient due to friction. In order to study the behavior, mass and momentum conservation equations were solved numerically using characteristic method during transient conditions. As a water hammer phenomena accompanies with large pressure gradient, so the pipeline equipment behavior and their effect were analyzed with respect to the maximum pressure occurrence. For a pipeline of 5000 m length, 1 m diameter, 1 m3/s discharge and 100 m height between upstream and downstream, the following result were concluded: 1-If the moment of inertia of the pump impeller increases by 400 percent, the maximum pressure occurred by the water hammer will decrease by 9 percent. 2-During on and off of the shut off valve, 80 percent of pressure increase due to water hammer was created during the last 15 percent of valve closure. 3-If pressure wave velocity increases by 75 percent, then the maximum pressure generated due to the water hammer will increase by 27 percent. 4-If the loss coefficient of the by pass line of the air chamber decreases by 90 percent, then the maximum pressure due to the water hammer will decrease by 20 percent. 5-If the pipeline Moody friction coefficient increases by 92 percent, the maximum pressure due to the water hammer will increase by 66 percent.

Sign in / Sign up

Export Citation Format

Share Document