Local cathodic protection design based on numerical simulation

2015 ◽  
Vol 62 (6) ◽  
pp. 407-415 ◽  
Author(s):  
Gan Cui ◽  
Zili Li ◽  
Lingyu Zhao ◽  
Xu Wei
Keyword(s):  
Numerical Simulation ◽  
Cathodic Protection ◽  
Real Life ◽  
High Energy ◽  
Shielding Effect ◽  
Content Type ◽  
Gas Stations ◽  
Protection Technology ◽  
Protection Potential ◽  
The Mathematical Model

Purpose – The purpose of this investigation was to study these problems and design regional cathodic protection, using numerical simulation. Regional cathodic protection technology is immature at home and abroad. This is reflected in the fact that in gas stations, there are many underground pipelines, which can lead to serious interference and shielding phenomena, and there are many grounding networks that can cause substantial loss of the cathodic protection current. Design/methodology/approach – Based on the above, in this article, first of all, the mathematical model of the buried pipeline cathodic protection potential distribution was established and the control equations solved using the boundary element method. Second, the cathodic shielding effect in pipeline concentration areas, the effect of instrument equipment grounding systems on cathodic protection and the influence of DC stray current on the interference of pipeline corrosion were studied separately using BEASY software. Finally, the BEASY software was used for a regional cathodic protection design for a real gas station. Findings – It was concluded that impressed current used in combination with sacrificial anodes for regional cathodic protection design is often the most economic and effective approach. However, the output current of the auxiliary anode is large with high energy consumption. In consequence, it may be recommended that the station pipelines should be laid on the ground, rather than under it. Originality/value – It is considered that the results can guide regional cathodic protection design for real-life installations very well.

Cathodic protection criteria of low alloy steel in simulated deep water environment

2020 ◽  
Vol 67 (4) ◽  
pp. 427-434
Author(s):  
Haijing Sun ◽  
Weihai Xue ◽  
Jiaxin Xu ◽  
Guoliang Chen ◽  
Jie Sun
Keyword(s):  
Shallow Water ◽  
Alloy Steel ◽  
Deep Water ◽  
Cathodic Protection ◽  
Water Environment ◽  
Deep Ocean ◽  
Low Alloy Steel ◽  
Content Type ◽  
Offshore Industry ◽  
Protection Potential

Purpose The purpose of this work is to provide theoretical guidance and experimental analysis for optimized cathodic protection (CP) design of low alloy steel in deep water environments. Design/methodology/approach In the present study, the CP criteria of 10Ni5CrMoV low alloy steel were investigated in a simulated deep water environment (350 m) regarding the theoretical protection potential and measured protection potential. The influences of hydrostatic pressure (HP) and temperature were also discussed in detail. The theoretical protection potential was analyzed with the Nernst equation, and the measured minimum protection potential was derived by extrapolating the Tafel portion of anodic polarization curves. Findings The results indicate that the minimum protection potential of low alloy steel shifts to a positive value in a deep-ocean environment. This can be attributed to the combined effects of HP and the temperature. Moreover, the temperature has a stronger influence compared with HP. The results suggest that the CP potential criteria used in shallow water are still applicable in the deep ocean, which is further confirmed through the SEM and x-ray diffraction analysis of the corrosion products resulted from the potentiostatic cathodic polarization experiments at −0.85 VCSE. Originality/value In recent decades, successful applications of CP for long-term corrosion protection of the steel components applied at a subsea level have enabled the offshore industry to develop reliable and optimized CP systems for shallow water. However, differences in the seawater environment at greater depths have raised concerns regarding the applicability of the existing CP design for deeper water environments. Hence, this research focuses on the CP criteria of low alloy steel in simulated deep water environment concerning the theoretical protection potential and measured protection potential. The influences of HP and temperature were also discussed.

Cathodic Protection Effect of Reinforced Concrete Beam Specimens with Zinc Sacrificial Anode in Marine Environment

2015 ◽  
Vol 1125 ◽  
pp. 345-349 ◽  
Author(s):  
Jin A Jeong
Keyword(s):  
Reinforced Concrete ◽  
Cathodic Protection ◽  
Concrete Beam ◽  
Salt Water ◽  
Reinforced Concrete Beam ◽  
Sacrificial Anode ◽  
Protection Technology ◽  
Concrete Resistivity ◽  
Protection Potential ◽  
Cathodic Protection System

This study is to acquire the confirmation data regarding the cathodic protection characteristics for reinforced concrete beam specimens with zinc sacrificial anode in 15% salt water. It was possible to confirm the performance of sacrificial anode cathodic protection system by the measurement of potentials and concrete resistivity for the reinforced concrete beam specimens applied with zinc sacrificial anode in mortar topside of the concrete specimens. The corrosion potential and cathodic protection potential were measured by potentiostat, and 4 hour depolarization potentials were measured after disconnecting with anode for 4 hours. It was confirmed that the cathodic protection for reinforced concrete structures by means of zinc sacrificial anode were very effective corrosion protection technology in marine environments.

scholarly journals Numerical simulation and experimental calibration of additive manufacturing by blown powder technology. Part I: thermal analysis

2017 ◽  
Vol 23 (2) ◽  
pp. 448-463 ◽  
Author(s):  
Michele Chiumenti ◽  
Xin Lin ◽  
Miguel Cervera ◽  
Wei Lei ◽  
Yuxiang Zheng ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Additive Manufacturing ◽  
Numerical Model ◽  
High Energy ◽  
Metal Deposition ◽  
Numerical Control ◽  
Experimental Calibration ◽  
Standard Format ◽  
Content Type ◽  
Scanning Pattern

Purpose This paper aims to address the numerical simulation of additive manufacturing (AM) processes. The numerical results are compared with the experimental campaign carried out at State Key Laboratory of Solidification Processing laboratories, where a laser solid forming machine, also referred to as laser engineered net shaping, is used to fabricate metal parts directly from computer-aided design models. Ti-6Al-4V metal powder is injected into the molten pool created by a focused, high-energy laser beam and a layer of added material is sinterized according to the laser scanning pattern specified by the user. Design/methodology/approach The numerical model adopts an apropos finite element (FE) activation technology, which reproduces the same scanning pattern set for the numerical control system of the AM machine. This consists of a complex sequence of polylines, used to define the contour of the component, and hatches patterns to fill the inner section. The full sequence is given through the common layer interface format, a standard format for different manufacturing processes such as rapid prototyping, shape metal deposition or machining processes, among others. The result is a layer-by-layer metal deposition which can be used to build-up complex structures for components such as turbine blades, aircraft stiffeners, cooling systems or medical implants, among others. Findings Ad hoc FE framework for the numerical simulation of the AM process by metal deposition is introduced. Description of the calibration procedure adopted is presented. Originality/value The objectives of this paper are twofold: firstly, this work is intended to calibrate the software for the numerical simulation of the AM process, to achieve high accuracy. Secondly, the sensitivity of the numerical model to the process parameters and modeling data is analyzed.

Numerical Simulation of Cathodic Protection Potential Distribution of Coastal Power Plant Condenser Based on Physical Scale Model

2014 ◽  
Vol 644-650 ◽  
pp. 3734-3738
Author(s):  
Peng Zhang ◽  
Juan Zhao ◽  
Gui Wang
Keyword(s):  
Numerical Simulation ◽  
Power Plant ◽  
Cathodic Protection ◽  
Potential Distribution ◽  
Simulation Analysis ◽  
Simulation Software ◽  
Scale Model ◽  
Physical Scale ◽  
Finite Element Numerical Simulation ◽  
Protection Potential

Finite element numerical simulation software was used for numerical simulation analysis of cathodic protection of coastal power plant condenser based on physical scale model. The effects of location, size and number of auxiliary anode on the cathodic protection potential distribution of the condenser were studied, which would predict cathodic protection result of the condenser and provide reasonable design for cathodic protection of the condenser.

Microenvironment evolution and SCC behavior of subsea pipeline within disbonded coating crevice in a seawater environment under cathodic protection

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Wei Zhang ◽  
Hongqun Liu ◽  
Minglei Hu ◽  
Wei Wu
Keyword(s):  
Cathodic Protection ◽  
Design Methodology ◽  
Tensile Tests ◽  
High Susceptibility ◽  
Content Type ◽  
Subsea Pipeline ◽  
Seawater Environment ◽  
Protection Potential ◽  
Disbonded Coating

Purpose This paper aims to make clear the sensitive zone of subsea pipeline to stress corrosion cracking (SCC) under a disbonded coating. Design/methodology/approach The change of microenvironment under a disbonded coating in artificial seawater was analyzed by using a rectangular crevice cell. The SCC behavior of subsea pipeline was studied by slow strain rate tensile tests. Findings The microenvironment at the crevice bottom exhibits obvious acidification, Cl- aggregation and cathodic protection potential (CP) rise. Accordingly, the susceptibility of X70 steels to SCC is high due to the intensive anodic dissolution effect. At the opening, hydrogen atom can access into the steel and induce hydrogen embrittlement effect on account of the applied over-protected CP potential, resulting in a relatively high susceptibility to SCC. The corrosiveness of the microenvironment at crevice middle, however, is mild with proper CP potential; thus, the susceptibility of X70 steel to SCC here is lower than that obtained at the opening and the crevice bottom. Originality/value A rectangular crevice cell is built to survey the microenvironment evolution under a disbonded coating in situ. The sensitive zone of subsea pipeline to SCC under a disbonded coating is clarified.

Supportability issues of mechanical systems for their useful life

2016 ◽  
Vol 14 (1) ◽  
pp. 33-53 ◽  
Author(s):  
M. Asjad ◽  
M.S. Kulkarni ◽  
O.P. Gandhi
Keyword(s):  
Research Work ◽  
Mechanical Systems ◽  
Real Life ◽  
National Capital Region ◽  
Compressed Natural Gas ◽  
Content Type ◽  
National Capital ◽  
Design Characteristics ◽  
The Mathematical Model ◽  
Original Equipment Manufacturers

Purpose – Original equipment manufacturers (OEMs) start providing support to their products, that helped them in beating the competition across the worldwide. The unavailability of spares and crews may also prolong the downtime of equipment, thereby affecting the systems’ performance. The spares and crews have as much effect on the systems’ performance as the design characteristics (i.e. reliability and maintainability). Thus, the OEMs required to extent the support to their products through maintenance, spares, crews, etc., so as to gain the customer satisfaction. Design/methodology/approach – The mathematical model for spares, crews and support quality has been presented in this research work. The problem has been identified from the literature perspective for mechanical systems. Findings – The model has been implemented on a real-life problem, in which the OEMs provide support to their make installed at compressed natural gas workstation in National Capital Region, India. Originality/value – The research proposed in this work will be helpful to manufacturer, customer, academician, researcher, industrialist and any concerned person, to get the exhaustive benefits from the system.

scholarly journals Research on feeder network design: a case study of feeder service for the port of Kotka

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Yisong Lin ◽  
Xuefeng Wang ◽  
Hao Hu ◽  
Hui Zhao
Keyword(s):  
Control System ◽  
Numerical Experiment ◽  
Network Design ◽  
Evaluation System ◽  
Real Life ◽  
Objective Evaluation ◽  
Multi Objective Optimization ◽  
Real Life Data ◽  
The Mathematical Model

Abstract By exemplifying the feeder service for the port of Kotka, this study proposed a multi-objective optimization model for feeder network design. Innovative for difference from the single-objective evaluation system, the objective of feeder network design was proposed to include single allocation cost, intra-Europe cargo revenue, equipment balance, sailing cycle, allocation utilization, service route competitiveness, and stability. A three-stage control system was presented, and numerical experiment based on container liner’s real life data was conducted to verify the mathematical model and the control system. The numerical experiment revealed that the three-stage control system is effective and practical, and the research ideas had been applicable with satisfactory effect.

scholarly journals A Pot-Like Vibrational Microfluidic Rotational Motor

Micromachines ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 177
Author(s):  
Suzana Uran ◽  
Matjaž Malok ◽  
Božidar Bratina ◽  
Riko Šafarič
Keyword(s):  
Mathematical Model ◽  
Rotational Speed ◽  
Mechanical Energy ◽  
Real Life ◽  
Frequency Region ◽  
Theoretical Research ◽  
Practical Challenge ◽  
The Mathematical Model ◽  
Motor Structure ◽  
Proper Balance

Constructing a micro-sized microfluidic motor always involves the problem of how to transfer the mechanical energy out of the motor. The paper presents several experiments with pot-like microfluidic rotational motor structures driven by two perpendicular sine and cosine vibrations with amplitudes around 10 μm in the frequency region from 200 Hz to 500 Hz. The extensive theoretical research based on the mathematical model of the liquid streaming in a pot-like structure was the base for the successful real-life laboratory application of a microfluidic rotational motor. The final microfluidic motor structure allowed transferring the rotational mechanical energy out of the motor with a central axis. The main practical challenge of the research was to find the proper balance between the torque, due to friction in the bearings and the motor’s maximal torque. The presented motor, with sizes 1 mm by 0.6 mm, reached the maximal rotational speed in both directions between −15 rad/s to +14 rad/s, with the estimated maximal torque of 0.1 pNm. The measured frequency characteristics of vibration amplitudes and phase angle between the directions of both vibrational amplitudes and rotational speed of the motor rotor against frequency of vibrations, allowed us to understand how to build the pot-like microfluidic rotational motor.

scholarly journals Characterization of Airborne Bacteria at an Underground Subway Station

2012 ◽  
Vol 78 (6) ◽  
pp. 1917-1929 ◽  
Author(s):  
Marius Dybwad ◽  
Per Einar Granum ◽  
Per Bruheim ◽  
Janet Martha Blatny
Keyword(s):  
Real Life ◽  
Performance Criteria ◽  
Anthropogenic Sources ◽  
Subway Station ◽  
Airborne Bacteria ◽  
Surveillance Systems ◽  
Operational Environment ◽  
Biological Detection ◽  
Content Type ◽  
Subway Stations

ABSTRACTThe reliable detection of airborne biological threat agents depends on several factors, including the performance criteria of the detector and its operational environment. One step in improving the detector's performance is to increase our knowledge of the biological aerosol background in potential operational environments. Subway stations are enclosed public environments, which may be regarded as potential targets for incidents involving biological threat agents. In this study, the airborne bacterial community at a subway station in Norway was characterized (concentration level, diversity, and virulence- and survival-associated properties). In addition, a SASS 3100 high-volume air sampler and a matrix-assisted laser desorption ionization–time of flight mass spectrometry-based isolate screening procedure was used for these studies. The daytime level of airborne bacteria at the station was higher than the nighttime and outdoor levels, and the relative bacterial spore number was higher in outdoor air than at the station. The bacterial content, particle concentration, and size distribution were stable within each environment throughout the study (May to September 2010). The majority of the airborne bacteria belonged to the generaBacillus,Micrococcus, andStaphylococcus, but a total of 37 different genera were identified in the air. These results suggest that anthropogenic sources are major contributors to airborne bacteria at subway stations and that such airborne communities could harbor virulence- and survival-associated properties of potential relevance for biological detection and surveillance, as well as for public health. Our findings also contribute to the development of realistic testing and evaluation schemes for biological detection/surveillance systems by providing information that can be used to mimic real-life operational airborne environments in controlled aerosol test chambers.

Sign in / Sign up

Export Citation Format

Share Document