Cathodic Protection Analysis of Spools With GRP Cover

2017 ◽  
Author(s):  
Randi B. Kongstein ◽  
Rannveig Kvande
Keyword(s):  
Cathodic Protection ◽  
Steel Surface ◽  
Ionic Current ◽  
Comsol Multiphysics ◽  
The Finite Element Method ◽  
Large Current ◽  
Bare Steel ◽  
Glass Fibre Reinforced ◽  
Current Lines ◽  
Subsea Pipelines

Cathodic protection (CP) design of pipelines is generally described in internationally recognized standards and recommended practices. However, not all cases can be solved by conventional CP calculations as recommended approaches and methods may not be fully defined in the standards. For instance, Glass fibre Reinforced Polyester (GRP) covers can be applied for mechanical protection (e.g. from trawl and/or dropped object) of subsea pipelines and structures. These GRP covers will restrict the electrical/ionic current lines between the anode and the steel surface to be cathodically protected. For a spool with in-line components requiring a large current (e.g. painted or bare steel) and with a GRP cover it may be difficult to obtain sufficient cathodic protection when applying simple mathematical calculations. This paper describes how the Finite Element Method (FEM) in COMSOL Multiphysics can be applied to show that the potential is acceptable for such cases.

An Investigation of the Distribution of Electric Potential and Space Charge in a Silicon Nanowire

2014 ◽  
Vol 69 (10-11) ◽  
pp. 597-605 ◽  
Author(s):  
A. Wesam Al-Mufti ◽  
Uda Hashim ◽  
Md. Mijanur Rahman ◽  
Tijjani Adam
Keyword(s):  
Finite Element Method ◽  
Space Charge ◽  
Electric Potential ◽  
Silicon Nanowire ◽  
Electrical Potential ◽  
Comsol Multiphysics ◽  
The Finite Element Method ◽  
Simulation Experiments ◽  
Different Dimensions

AbstractThe distribution of electric potential and space charge in a silicon nanowire has been investigated. First, a model of the nanowire is generated taking into consideration the geometry and physics of the nanowire. The physics of the nanowire was modelled by a set of partial differential equations (PDEs) which were solved using the finite element method (FEM). Comprehensive simulation experiments were performed on the model in order to compute the distribution of potential and space charge. We also determined, through simulation, how the characteristic of the nanowire is affected by its dimensions. The characterization of the resulting nanowire, calculated by COMSOL Multiphysics, shows different dimensions and their effect on space charge and electrical potential

Silica Nanocomposite Membrane for Dehumidification

2017 ◽  
Author(s):  
Omar Almahmoud ◽  
Tae-Youl Choi ◽  
Young-Soo Seo ◽  
Hyo-Sun Kim ◽  
Kevin A. Johnson
Keyword(s):  
Water Vapor ◽  
Flow Rate ◽  
Driving Forces ◽  
Comsol Multiphysics ◽  
The Finite Element Method ◽  
Dry Air ◽  
Hydrophobic Polymer ◽  
Silica Nanocomposite ◽  
Novel Design ◽  
Polyurethane Membrane

Various designs of novel membrane (silica nanocomposite polyurethane membrane) were tested for its optimal configuration in a membrane-based dehumidification system. This membrane was designed with a hydrophobic polymer matrix with hydrophilic silica nanochains. In this dehumidification process, two driving forces were suggested: concentration gradient of water vapor in the atmospheric air channel due to sweep gas and pressure gradient due to vacuum. This paper describes validation of the model configurations using the finite element method software (COMSOL Multiphysics) with experiments. Pressurized air enters an air duct at 1–5 liters per minute flow rate. Air is then humidified using a misting nozzle until saturation. Then the humid air passes by the membrane with a vacuum pump connected vertically to the duct to maximize the dehumidification rate. A novel design showed water vapor reduction from 19.4 grams of water vapor per kilogram of dry air to 16.9 grams of water vapor per kilogram of dry air for the 1 liter per minute flow rate of the 47 mm diameter membrane.

Integrity Challenges Associated with Stray Current Corrosion Across Monolithic IJ's and Resolutions

2021 ◽  
Author(s):  
Ebrahim Salem Al Salemi ◽  
Saleh Salem Al Ameri ◽  
Ajiv Mohan Nair ◽  
Humaid Musabah Al Ali ◽  
Mario Jr Javier Zantua ◽  
...  
Keyword(s):  
Cathodic Protection ◽  
Ionic Current ◽  
Low Carbon Steel ◽  
Internal Surface ◽  
Low Carbon ◽  
Stray Current ◽  
Gas Industry ◽  
Factors Affecting ◽  
Steel Material ◽  
Internal Lining

Abstract Corrosion and subsequent failures is one of the main factors affecting uninterrupted operations of Oil & Gas Industries. Pipelines are considered as most convenient means of crude and gas transportation in Oil & Gas Industry. Buried pipelines generally made of low carbon steel material are protected externally by coating and applying impressed current cathodic protection (ICCP). Monitoring and maintaining adequate level of Cathodic Protection (CP) for such pipelines remains challenging for corrosion engineers due to increased level of field congestion, complexity in accurate current mapping and mitigation of corrosion phenomena. Failure of pipelines due to corrosion can be catastrophic with following consequences: Loss of containment fluid and thereby probable fatalityDamage to asset/company reputationSafety and Environment (Fire, Toxic gases and Oil Spill)Resource and downtime cost impact Isolation joints IJ's are designed with very high insulating material at mating areas and installed on pipelines by welding to avoid loss of Cathodic Protection (CP) current. Due to high electrical insulation, a potential difference is formed across of IJ's due to applied CP current and stray currents. In upstream Oil & Gas Industry, multiphase crude transported via pipeline will have certain percentage of water and will induce an internal conductive path across the IJs resulting in ionic current discharge at anodic areas within internal surface. This study focuses on factors contributing to such internal stray current corrosion, limitation in monitoring methodology and mitigation programs. The study concludes with recommendations such as design modifications, improvement in internal lining properties and improved installation guidelines. The study practically illustrates effectiveness of combined resistive bonding and zinc earthing cells installation for controlling stray current propagation in order to reduce the corrosion rate so as to maintain Integrity of pipelines.

Simulation and Test of through Silicon Vias Impacted by Large Current Pulse

2015 ◽  
Vol 645-646 ◽  
pp. 190-194
Author(s):  
Xu Ran Ding ◽  
Ya Bin Wang ◽  
Wen Zhong Lou ◽  
Fang Yi Liu
Keyword(s):  
Theoretical Model ◽  
Failure Mechanism ◽  
Current Pulse ◽  
Comsol Multiphysics ◽  
Testing System ◽  
Through Silicon Vias ◽  
Large Current ◽  
Weak Points ◽  
Silicon Vias

The failure mechanism of through silicon vias impacted by large current pulse is reported. A theoretical model has been built to describe how TSVs fails when impacted by large current pulse. The theoretical model is then solved by applying COMSOL Multiphysics and the weak points of the TSV have been pointed out. By applying the large current pulse generating and testing system, an experiment has been done to verify the theoretical model. The results show that although the TSVs may be broken down when impacted by large current pulse, it can still be function by using several TSVs in parallel.

Characterization of steel surface under cathodic protection in seawater

2013 ◽  
Vol 60 (3) ◽  
pp. 160-167 ◽  
Author(s):  
Mariela Rendón Belmonte ◽  
José Trinidad Pérez Quiroz ◽  
Benjamín Valdez Salas ◽  
Miguel Martínez Madrid ◽  
Andrés Torres Acosta ◽  
...  
Keyword(s):  
Cathodic Protection ◽  
Steel Surface

scholarly journals Análisis, diseño y simulación multifísica de una antena Fotoconductora Terahertz usando el método de elementos finitos

Ingeniería ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 378-392
Author(s):  
Diana Gonzalez Galindo ◽  
Cristhian Torres Urrea ◽  
Oscar Fabian Corredor Camargo ◽  
David Suarez Mora ◽  
Carlos Criollo Paredes
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Construction Materials ◽  
Comsol Multiphysics ◽  
The Finite Element Method ◽  
Intrinsic Properties ◽  
Photoconductive Antennas ◽  
Mathematical Foundations ◽  
Non Destructive ◽  
Theoretical Foundations

Context: The study of nanotechnology has shown great advances, which include research and exploration of the TeraHertz (THz) region, where one of the most common approaches is the use of photoconductive antennas (PCA) due to the intrinsic properties of their emission the non-destructive nature of this type of radiation. Method: This paper describes the concept of antenna its radiation principles, the mathematical foundations, the material used for radiation, and the adjustment of the parameters to find a result of the pulse in THz by using the finite element method, accessible in the COMSOL Multiphysics software. Results: The result of a computational modeling is presented, which studies the behavior of a PCA, where the input of the chosen model corresponds to the geometry and material of the antenna, thus showing the concentration of the electric field in the GAP zone of the dipole and the substrate of the semiconductor. Conclusions: Given the theoretical foundations that describe the behavior of PCAs in THz, it was possible to configure parameters such as the geometry of the antenna, the laser to be used, and the construction materials to achieve the generation of a photocurrent peak in the order of 0,1-1,2 THz.

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