Effect of liquid flow velocity on corrosion behavior of 20# steel at initial stage under gas-liquid two-phase plug flow condition

2020 ◽  
Vol 67 (4) ◽  
pp. 415-425
Author(s):  
Guirong Yang ◽  
Wenming Song ◽  
Zibo Zhu ◽  
Ying Ma ◽  
Yuan Hao
Keyword(s):  
Corrosion Rate ◽  
Flow Velocity ◽  
Liquid Flow ◽  
Pipe Wall ◽  
Liquid Velocity ◽  
Plug Flow ◽  
Corrosion Products ◽  
Two Phase ◽  
Content Type ◽  
Corrosion Time

Purpose The paper aims to study the effect of liquid flow velocity on corrosion behavior of 20# steel at initial stage under (CO2/aqueous solution) gas–liquid two-phase plug flow conditions. Design/methodology/approach Weight loss, scanning electron microscopy, energy-dispersive X-ray spectroscopy and XPS methods were used in this study. Findings The corrosion rate increased with the increasing liquid flow velocity at any different corrosion time. The corrosion rate decreased with the extension of corrosion time at the same liquid flow velocity. There was no continuous corrosion products film on the whole pipe wall at any different corrosion time. The macroscopic brown-yellow corrosion products on the pipe wall surface decreased with the increasing liquid flow velocity and the loose floccus corrosion products decreased gradually until these products were transformed into un-continuous needle-like dense products with the increasing liquid velocity. The main elements among the products film were Fe, C and O, and the main phases of products film on the pipe wall were Fe3C, FeCO3, FeOOH and Fe3O4. When the corrosion time was 1 h under different liquid–velocity condition, the thickness of local corrosion products film was from 3.5 to 3.8 µm. Originality/value The ion mass transfer model of corrosion process in pipe was put forward under gas–liquid two-phase plug flow condition. The total thickness of diffusion sublayer and turbulence sublayer decreased as well as the turbulence propagation coefficient increased with the increasing liquid velocity, which led to the increasing velocity of ion transfer during corrosion process. This was the fundamental reason for the increase of corrosion rate with the increasing liquid velocity.

Corrosion behavior of 20# steel in aqueous CO2 solution under stratified gas-liquid two-phase flow condition

2019 ◽  
Vol 66 (1) ◽  
pp. 11-18
Author(s):  
Guirong Yang ◽  
Wenming Song ◽  
Fuqiang Wang ◽  
Ying Ma ◽  
Yuan Hao
Keyword(s):  
Corrosion Rate ◽  
Flow Condition ◽  
Two Phase Flow ◽  
Corrosion Products ◽  
Dense Layer ◽  
Phase Flow ◽  
Two Phase ◽  
Content Type ◽  
X Ray ◽  
Loose Layer

PurposeThis paper aims to investigate the corrosion rate, surface morphology and composition of corrosion products of 20# seamless steel in aqueous CO2 solution under stratified gas-liquid two-phase flow condition. The development of a corrosion products layer has also been discussed. Design/methodology/approachThe following methods were used: weight loss method, scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction. FindingsThe corrosion rate curve presents an irregular zigzag change trend with a gradual increase in time. The peak value of the corrosion rate appears when the corrosion time is 4 h and 8 h. The corrosion products layer is composed of two sub-layers: the inner dense layer that is about 6 µm thick and the outer loose layer that is about 9 µm thick when the corrosion time is 8 h. The main corrosion product are FeCO3 and Fe2O3. Originality/valueThe atomic ratio of Fe/C/O is relatively stable for the inner dense layer, but changes in thickness for the outer loose layer. There is a densification stage after a loose corrosion products layer forms, and it is periodic.

Non-Invasive Method for Velocity and Slug Length Measurements in Gas/Liquid Flow in Horizontal Pipes

2005 ◽  
Author(s):  
S. Al-Lababidi ◽  
M. L. Sanderson
Keyword(s):  
Liquid Flow ◽  
Liquid Velocity ◽  
Correlation Technique ◽  
Translational Velocity ◽  
Two Phase ◽  
Horizontal Pipe ◽  
Horizontal Pipes ◽  
Non Invasive ◽  
Gas Liquid Flow ◽  
Superficial Gas Velocity

A method was developed for the measurement of slug frequency, slug velocity and slug length of two-phase gas/liquid flow under slug conditions in 2-inch horizontal pipe. The method consists of two pairs of ultrasonic transducers with 1MHz frequency. Non-invasive detection for slugs was achieved over a range of (0.1–1 ms−1) superficial liquid velocity and (0.1–3 ms−1) superficial gas velocity. The slug translational velocity was measured using a cross correlation technique for the modulated ultrasonic signals received. The slug length was measured after measuring the slug time t(slug) and slug translational velocity. The slug parameters measured were extensively compared with conductivity probes measurements and experimental correlations.

Design and Performance of Slug Damper

2008 ◽  
Vol 130 (4) ◽  
Author(s):  
Antonio Reinoso ◽  
Luis E. Gomez ◽  
Shoubo Wang ◽  
Ram S. Mohan ◽  
Ovadia Shoham ◽  
...  
Keyword(s):  
Flow Rate ◽  
Liquid Flow ◽  
Liquid Flow Rate ◽  
Liquid Velocity ◽  
Flow Behavior ◽  
Mechanistic Model ◽  
Gas Velocity ◽  
Flow Loop ◽  
Two Phase ◽  
Superficial Gas Velocity

This study investigates theoretically and experimentally the slug damper as a novel flow conditioning device, which can be used upstream of compact separation systems. In the experimental part, a 3 in. ID slug damper facility has been installed in an existing 2 in. diameter two-phase flow loop. This flow loop includes an upstream slug generator, a gas-liquid cylindrical cyclone (GLCC©, ©The University of Tulsa, 1994) attached to the slug damper downstream and a set of conductance probes for measuring the propagation of the dissipated slug along the damper. Over 200 experimental runs were conducted with artificially generated inlet slugs of 50 ft length (Ls/d=300) that were dumped into the loop upstream of the slug damper, varying the superficial liquid velocity between 0.5 ft/s and 2.5 ft/s and superficial gas velocity between 10 ft/s and 40 ft/s (in the 2 in. inlet pipe) and utilizing segmented orifice opening heights of 1 in., 1.5 in., 2 in., and 3 in. For each experimental run, the measured data included propagation of the liquid slug front in the damper, differential pressure across the segmented orifice, GLCC liquid level, GLCC outlet liquid flow, and static pressure in the GLCC. The data show that the slug damper/GLCC system is capable of dissipating long slugs, narrowing the range of liquid flow rate from the downstream GLCC. Also, the damper capacity to process large slugs is a strong function of the superficial gas velocity (and mixture velocity). The theoretical part includes the development of a mechanistic model for the prediction of the hydrodynamic flow behavior in the slug damper. The model enables the predictions of the outlet liquid flow rate and the available damping time, and in turn the prediction of the slug damper capacity. Comparison between the model predictions and the acquired data reveals an accuracy of ±30% with respect to the available damping time and outlet liquid flow rate. The developed model can be used for design of slug damper units.

Corrosion behavior of carbon steel in H2S-CO2-H2O-methyldiethanolamine (MDEA) solution under the presence of chloride ions

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Guiyang Wu ◽  
Xikui Gu ◽  
Wanwei Zhao ◽  
Rui Fan ◽  
Ting Mao
Keyword(s):  
High Temperature ◽  
Carbon Steel ◽  
Low Temperature ◽  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Chloride Ion ◽  
Chloride Ions ◽  
Corrosion Products ◽  
Content Type

Purpose This paper aims to study the effect of chloride ions concentration on the corrosion behavior of carbon steel in methyldiethanolamine (MDEA) aqueous solution in the sight of different process parameters of purification plant. Design/methodology/approach Due to the decrease of filtration efficiency and separation efficiency, the chloride ion in the desulfurization solution is enriched. The corrosion behavior of carbon steel under chloride ion enrichment environment was studied by weight-loss method, electrochemical impedance spectroscopy, cyclic polarization curve, X-ray photoelectron spectroscopy and scanning electron microscopy. Findings The results show that temperature and hydrogen sulfide loads are the main factors of corrosion in CO2-MDEA-H2O-H2S environment. The enrichment of chloride ions reduces the corrosion rate at low temperature but promotes the corrosion rate at high temperature. The chloride concentration should be controlled below 3000 mg/L, and no pitting corrosion was found under the experimental conditions. Originality/value The effect of chloride ion enrichment on MDEA solution corrosion shows that at low temperature, the increase of chloride ion will reduce the acid gas load and increase the density of corrosion products, so as to reduce the corrosion; on the contrary, at high temperature, the density of corrosion products will decrease and the corrosion will be intensified as well. It is believed that the chloride ion should be controlled below 3000 mg/L according to the results of the tests.

Development of Prediction Technology of Two-Phase Flow Dynamics Under Earthquake Acceleration — (4) Measurement of Bubble Deformation Near Wall Under Flow Rate Fluctuation

2012 ◽  
Author(s):  
Satoshi Okachi ◽  
Masaki Seto ◽  
Hideaki Monji ◽  
Akiko Kaneko ◽  
Yutaka Abe ◽  
...  
Keyword(s):  
Flow Rate ◽  
Two Phase Flow ◽  
Pipe Wall ◽  
Flow Behavior ◽  
Plug Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Horizontal Pipe ◽  
Bubble Deformation ◽  
Rate Fluctuation

In order to clear the two-phase flow behavior under earthquake, a systematic study is done experimentally and numerically. The present study is one on the series of the study on two-phase flow under earthquake, and focuses on the flow rate fluctuation. The flow rate fluctuation was added to bubbly or plug flow in a horizontal pipe, and flow behavior was measured by PIV and image processing. The bubble deformation near the pipe wall was observed and the velocity field around the bubble was shown. The bubble coalescence was also observed under the flow rate fluctuation condition.

Towards Understanding Two-Phase Flow Induced Vibration of Piping Structure With Flow Restricting Orifices

2017 ◽  
Author(s):  
Olufemi E. Bamidele ◽  
Wael H. Ahmed ◽  
Marwan Hassan
Keyword(s):  
Flow Pattern ◽  
Flow Rate ◽  
Liquid Flow ◽  
Slug Flow ◽  
Two Phase Flow ◽  
Liquid Flow Rate ◽  
Liquid Velocity ◽  
Phase Flow ◽  
Flow Induced Vibration ◽  
Two Phase

The current work studies air-water flow through a ½-inch flow restricting orifice installed in a 1-inch pipe. Investigation of two phase flow downstream the orifice and its effects on vibration of the piping structure have been carried out. Several flow regimes from bubbly to stratified-wavy flow have been analyzed to evaluate the effects of flow pattern, phase redistribution, bubble frequency, and liquid flow rate on the vibration of the structure. The liquid velocity fields have been obtained using Particle Image Velocimetry (PIV) along with post processing algorithm for phase discrimination. Proximity sensors have been used to capture the pipe response in two orthogonal directions. Also, a capacitance sensor was used to measure the two-phase void fraction. The results show that the magnitude and nature of vibrations of the piping structure is largely affected by the frequency and size of the bubbles upstream, vortex creation by pressure fluctuation downstream, liquid flow rate, and the flow pattern upstream. Slug flow and stratified flow patterns induced significant vibrations in the examined structure. The location of the transition region of slug flow on flow pattern maps, play important role in the dynamic response of the structure to the flow.

The effect of the hydrodynamic and temperature on corrosion rate of API steels exposed to oilfield produced water

2019 ◽  
Vol 66 (1) ◽  
pp. 101-114 ◽  
Author(s):  
Luis Manuel Quej-Ake ◽  
Antonio Contreras ◽  
Hongbo Liu ◽  
Jorge L. Alamilla ◽  
Eliceo Sosa
Keyword(s):  
Reynolds Number ◽  
Corrosion Rate ◽  
Produced Water ◽  
Rotation Speed ◽  
Corrosion Products ◽  
Hydrodynamic Condition ◽  
Activation Process ◽  
Content Type ◽  
Oilfield Produced Water ◽  
Natural Solution

PurposeThe purpose of this paper is to study the corrosion rate for X52, X60, X65, X70 and X80 steel immersed in Mexican oilfield produced water. For the electrochemical characterization of the five steels rotating disk electrodes, 20°C, 30°C and 45°C of experimental temperature and 0, 500, 1,000 and 2,000 rpm of rotation speed were taken into account. The temperature dependence was analyzed using Arrhenius law. Thus, Rct values obtained from EIS data in comparison with the corrosion rate obtained from polarization curves data were taken into account. Hydrodynamic effects were analyzed by Rct and corrosion rate data.Design/methodology/approachElectrochemical impedance spectroscopy and potentiodynamic polarization techniques were used to assess the electrochemical behavior for five pipe steels steel immersed in a natural solution.FindingsThe resistance and corrosion rate taken from electrochemical tests decreased as temperature and hydrodynamic condition also decreased. In addition, the Arrhenius parameter revealed that the natural solution increased the corrosion rate as the activation energy decreased. Typical branches related to reduction-oxidation reaction (dissolution-activation process or corrosion products dissolution) on steel surface were discussed. Optical images analysis shows that corrosion products for X65 steel exposed to oilfield produced water can be attributed to more susceptibility to corrosion damage for this steel grade (Quej-Ake et al., 2018), which is increased with the temperature and rotation speed of the working electrode.Originality/valueCorrosion process of the five steels exposed to oilfield produced water could be perceptive when Arrhenius analysis is taken into account. This is because oilfield produced water is the most aggressive condition (brine reservoir and sour water) for internal pipelines walls and storage tanks (brine tanks). Thus, stagnant condition was considered as a more extreme corrosive condition because produced water is stored in atmospheric stationary tanks as well as it is transported under laminar condition in zones where oilfield produced water is maintaining in the bottom of the pipe during the production, transporting and storing of the crude oil. In addition, a brief operational process for Reynolds number and the flowrate of the stock tank barrel per day (Q in STBD) using field and Reynolds number data is discussed.

Analysis of the Liquid Flow in a Vessel with a Rotating Disk at the Liquid Surface

2014 ◽  
Vol 35 (1) ◽  
pp. 3-18 ◽  
Author(s):  
Witold Suchecki
Keyword(s):  
Free Surface ◽  
Flow Velocity ◽  
Liquid Flow ◽  
Liquid Velocity ◽  
Rotating Disk ◽  
Velocity Fields ◽  
Cylindrical Coordinate ◽  
Disc Rotation ◽  
Flow Phenomena ◽  
The Relationship

Abstract This study is concerned with liquid flow induced by a disk which rotates steadily around its axis and touches the free surface of liquid contained in a cylindrical vessel. It is a simplified model of the flow in the inlet part of a vertical cooling crystallizer where a rotary distributor of inflowing solution is situated above the free surface of solution contained in the crystalliser. Numerical simulations of flow phenomena were conducted and the simulation results were interpreted assuming an analogy with Kármán’s theoretical equations. In a cylindrical coordinate system, the components of flow velocity were identified as functions of distance from the surface of the rotating disk. The experimental setup was developed to measure velocity fields, using digital particle velocimetry and optical flow. Conclusions concerning the influence of disc rotation on liquid velocity fields were presented and the experimental results were found to confirm the results of numerical simulation. On the basis of simulation data, an approximation function was determined to describe the relationship between the circumferential component of flow velocity and the distance from the disk.

Hydrogen Permeation Behavior of 95S3Cr Casing with Wet H2S Environment

2012 ◽  
Vol 229-231 ◽  
pp. 159-162
Author(s):  
Qiu Li Zhang ◽  
Zhen Jiang Ji ◽  
Jun Zhou ◽  
Xiang Yang Chen
Keyword(s):  
Corrosion Rate ◽  
Hydrogen Permeation ◽  
Corrosion Products ◽  
Before And After ◽  
Corrosion Time

This paper discusses the amount of hydrogen permeation and corrosion rate of 95S3Cr casing in different time, and analyzes its morphology before and after corrosion. We conclude that hydrogen permeation increases with increases of corrosion time, and increasing speed is faster in the initial stages then slower. Corrosion rate is quickly dropped at the beginning and then gradually increased. Corrosion products are loose structure. Because of hydrogen permeate into the material, the cracks create. It accelerates the corrosion.

Design and Performance of Slug Damper

2007 ◽  
Author(s):  
Antonio Reinoso ◽  
Luis E. Gomez ◽  
Shoubo Wang ◽  
Ram S. Mohan ◽  
Ovadia Shoham ◽  
...  
Keyword(s):  
Flow Rate ◽  
Liquid Flow ◽  
Liquid Flow Rate ◽  
Liquid Velocity ◽  
Flow Behavior ◽  
Mechanistic Model ◽  
Gas Velocity ◽  
Flow Loop ◽  
Two Phase ◽  
Superficial Gas Velocity

A novel flow conditioning device, namely, the slug damper, which can be used upstream of compact separation systems, is investigated theoretically and experimentally. In the experimental part, a 3” ID slug damper facility has been installed in an existing 2” diameter two-phase flow loop. This flow loop includes an upstream slug generator, a Gas-Liquid Cylindrical Cyclone (GLCC©) attached to the slug damper downstream, and a set of conductance probes for measuring the propagation of the dissipated slug along the damper. Over 200 experimental runs were conducted with artificially generated inlet slugs of 50 ft length (Ls/d = 300) that were dumped into the loop upstream of the slug damper, varying the superficial liquid velocity from 0.5 to 2.5 ft/s and superficial gas velocity between 10 to 40 ft/ (in the 2” inlet pipe) and utilizing segmented orifice opening heights of 1”, 1.5”, 2” and 3”. For each experimental run, the measured data included: propagation of the liquid slug front in the damper, differential pressure across the segmented orifice, GLCC liquid level, GLCC outlet liquid flow and static pressure in the GLCC. The data prove that the slug damper is capable of dissipating long slugs, ensuring fairly constant liquid flow rate into the downstream GLCC. Also, the damper capacity to process large slugs is a strong function of the superficial gas velocity (and mixture velocity). The theoretical part includes the development of a mechanistic model for the prediction of the hydrodynamic flow behavior in the slug damper. The model enables the predictions of the outlet liquid flow rate and the available damping time, and in turn the prediction of the slug damper capacity. Comparison between the model predictions and the acquired data reveals an accuracy of 30% with respect to the available damping time and outlet liquid flow rate. The developed model can be used for design of slug damper units in the field.

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