Effectiveness of cathodic protection of UNS N04400 heat exchanger tubes for sea water service

1995 ◽  
Vol 30 (4) ◽  
pp. 312-316 ◽  
Author(s):  
A. AL-HASHEM ◽  
J. CAREW
Keyword(s):  
Heat Exchanger ◽  
Cathodic Protection ◽  
Sea Water ◽  
Water Service

scholarly journals Cathodic protection of structures in seawater using solar panels

2019 ◽  
Vol 121 ◽  
pp. 02004
Author(s):  
Boris Borisovich Chernov ◽  
Van Mung Vu ◽  
Anac Maskharovich Nugmanov ◽  
Lyudmila Yuryevna Firsova
Keyword(s):  
Cathodic Protection ◽  
Sea Water ◽  
Cathode Current Density ◽  
Complete Agreement ◽  
Low Alloy Steels ◽  
Solar Panels ◽  
Protective Properties ◽  
Theoretical Concepts ◽  
Alloy Steels ◽  
Cathode Current

It is well known that the cathodic protection of structures in seawater is accompanied by the formation of calcareous deposits on them. In current study, we consider the physicochemical modelling of the formation of the deposit composition against cathode current density in seawater. The reliability of the model representations is confirmed by direct experiments. The work also studied the protective properties of the deposits with a different composition for low-alloy steels in natural sea water. It has been shown that the deposits of pure Mg(OH)2 and the deposits of CaCO3 + Mg(OH)2 had better protective ability against corrosion than the deposits of pure CaCO3. However, the deposits of Mg(OH)2 dissolved faster than the deposits of CaCO3 and CaCO3 + Mg(OH)2. Theoretical concepts and experiments on the laws governing the formation of the deposits and their protective properties are in complete agreement with each other. This allows to use the obtained patterns in the cathodic protection of structures in sea water using solar panels, forming standard deviations with predetermined protective properties in the daytime.

Experimental Studies on the Seawater Desalination System Based on Ocean Thermal Energy Conversion

2013 ◽  
Vol 448-453 ◽  
pp. 3254-3258
Author(s):  
Feng Yun Chen ◽  
Wei Min Liu ◽  
Liang Zhang
Keyword(s):  
Heat Exchanger ◽  
Energy Conversion ◽  
Thermal Energy ◽  
Sea Water ◽  
Economic Benefits ◽  
Seawater Desalination ◽  
Tube Heat Exchanger ◽  
Ocean Thermal Energy Conversion ◽  
Thermal Energy Conversion ◽  
Ocean Thermal Energy

Seawater desalination system has been established based on the ocean thermal energy conversion in this paper. Through compared finned tube heat exchanger with round tube heat exchanger obtained the fresh water output at different temperature and flow velocity of the warm and cold sea water. In this system the energy of the warm and cold sea water has been fully utilized, and so improved the economic benefits of the ocean thermal energy conversion.

scholarly journals Performance Evaluation of Shell-and-Tube Heat Exchanger with 3-Fluid Sets using CFD and NTU

2019 ◽  
Vol 9 (1) ◽  
pp. 1416-1420
Keyword(s):  
Heat Exchanger ◽  
Industrial Development ◽  
Cfd Simulation ◽  
Sea Water ◽  
Raw Water ◽  
Power Sector ◽  
Tube Heat Exchanger ◽  
Shell And Tube ◽  
Pass Through ◽  
Good Agreement

Energy generation to the present growing population is a crucial challenge for the power sector. Heat exchangers (HE) plays an important role in the industrial development. In this present work an attempt is made to develop a Shell-and- Tube Heat Exchanger (STHE) with segmental baffles using commercial CATIA V5 and Autodesk CFD Simulation Softwares. TEMA standards are considered for design of STHE with baffle-cut of 25%. 3-different sets of fluids are allowed to pass through the shell and tube sides i.e. Methanol - Sea Water (M-S), Distilled Water – Raw Water (D-R) and Kerosene- Crude Oil (K-C). The boundary conditions imposed for analysis are fluid inlet temperatures and velocities. ϵ-NTU is employed for the validation of simulation results and found good agreement between them. Results are plotted for temperature, pressure and velocity contours. The performance of the STHE is shown best for the K-C fluid set among other fluid sets.

Calibration of the AC Potential Dropping System (ACPD) for Determination of Crack Growth in API 5L X65 Steel under Cathodic Protection Effect

2020 ◽  
Vol 1012 ◽  
pp. 412-417
Author(s):  
Misael Souto de Oliveira ◽  
Antonio Almeida Silva ◽  
Marco Antonio dos Santos ◽  
Jorge Antonio Palma Carrasco ◽  
João Vitor de Queiroz Marques
Keyword(s):  
Crack Growth ◽  
Marine Environment ◽  
Cathodic Protection ◽  
Sea Water ◽  
Potential Drop ◽  
Mechanical Tests ◽  
Flow Density ◽  
Type Specimens ◽  
X65 Steel ◽  
Api 5L X65 Steel

In this work the calibration of an Alternative Current Potential Drop (ACPD) system was performed to monitore laboratory mechanical tests on marine environment under cathodic protection. The calibration was done on CT type specimens of API 5L X65 steel dimensioned according to ASTM E1820 standard., The crack propagation during a tensile test with displacement control in an ACPD equipment was monitored through the performs points collection by two channels: one that monitors the crack growth and another that monitors a region free of crack. Using a profile projector and graphical data processing and analysis software, the area of ​​the fracture surface of the specimen was meansured, which allowed to correlate a crack size with a corresponding value of potential drop and the calibration curve. In order to verify verify the efficacy and precision of the technique, step loading tests were performed on API 5L X65 steel test specimens, submerged in synthetic sea water under the overprotection potential of-1300mVAg/AgCl. The results of the calibration showed few dispersed errors, and the main factors of this dispersion may be related to the geometry of the specimen and with variations in current flow density, which is influenced by corners and edges and by the presence of pick-up inductive. The calibration and its effectiveness can be verified through the results of the tests in marine environment, presenting crack lengths close to the actual values, confirming the effectiveness of the ACPD technique.

Fracture Mechanics Integrity Assessment of Stud Bolts Subjected to Cathodic Protection

2020 ◽  
Author(s):  
Mario A. L. de Castro ◽  
Fabio Alves ◽  
Kumarswamy Karpanan ◽  
Anand Venkatesh
Keyword(s):  
Fracture Mechanics ◽  
Cathodic Protection ◽  
Atomic Hydrogen ◽  
Sea Water ◽  
Circular Crack ◽  
Relative Increase ◽  
Maximum Increase ◽  
Integrity Assessment ◽  
Thread Root ◽  
Metallic Parts

Abstract Exposure of metallic parts to cathodic protection (CP) in sea water leads to production and diffusion of atomic Hydrogen into the metal matrix. Absorption of atomic Hydrogen into the metal could lead to hydrogen embrittlement (HE). In order to study the influence of stresses related to HE, FEA and Fracture Mechanics (FM) assessments were performed on a stud bolt threaded geometry. Effects of manufacturing tolerances, interface between nut and stud bolt and a defect in the form of a semi-circular crack placed in highest stress location of a thread root were also considered. Investigations of stress profiles when tension or bending are applied in test samples for measurement of HE threshold were also done, aiming at showing gaps on ASTM F1624-12 [1]. Tolerance assessment shows a relative maximum increase of 260% of nominal linearized membrane plus bending (NLMB) stresses regarding the nut runout [2] and for the proprietary nut geometry, such relative increase drops to 126% of NLMB stresses. Highest Hydrogen concentrations could be observed in the neighborhood of the first loaded thread root. FEA of cracked geometry shows that Hydrogen concentration could increase by around 283% around the crack tip, when compared to stud bolt in unloaded condition. Integrity assessment according to API 579-1 [3] or BS 7910 [4] and tests conducted according to ASTM F1624-12 [1] show less conservative results.

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