scholarly journals Research on Formation Mechanism of Trailing Oil in Product Oil Pipeline

2018 ◽  
Author(s):  
Enbin Liu ◽  
Wensheng Li ◽  
Hongjun Cai ◽  
Shanbi Peng
Keyword(s):  
Boundary Layer ◽  
Pipe Wall ◽  
Viscous Force ◽  
Refined Oil ◽  
Convection Diffusion ◽  
Oil Pipeline ◽  
Oil Transportation ◽  
The Dead ◽  
Modified Formula

Trailing oil is the tail section of contamination. There are two main reasons for the formation of trailing oil, one is the effect of laminar flow boundary layer, the other is the outflow of the preceding batch remained in the dead-legs. In the batch transportation of refined oil, under the action of viscous force, the preceding batch forms laminar boundary layer near the pipe wall and stays on the pipe wall, resulting in the phenomenon of contamination trailing and formation of trailing oil. When oil passes through the valve chamber of the oil transportation station, dead-leg will be formed. Due to gravity and convection diffusion, preceding batch flowing from dead-legs will form trailing oil in the pipeline. The phenomenon of trailing oil exists in the process of batch transportation, which will have an effect on the quality of oil. In this paper, Reynolds time-averaged method is used to simulate turbulence.Computational Fluid Dynamics(CFD) software is used to simulate different flow rates and bypass lengths to obtain contamination-related experimental data.Matlab software is used to perform multi-nonlinear regression for the oil substitution time, the length of the bypass and the flow rate. The formula for calculating the length of the trailing oil produced by the dead-leg is obtained. The modified formula for calculating the length of the contamination is obtained by combining the existing formula for calculating the length of the contamination.

scholarly journals Formation Mechanism of Trailing Oil in Product Oil Pipeline

Processes ◽  
2018 ◽  
Vol 7 (1) ◽  
pp. 7 ◽  
Author(s):  
Enbin Liu ◽  
Wensheng Li ◽  
Hongjun Cai ◽  
Shanbi Peng
Keyword(s):  
Formation Mechanism ◽  
Diesel Oil ◽  
Flow Speed ◽  
Oil Pipeline ◽  
Computational Fluid Dynamics Cfd ◽  
The Dead ◽  
Predicted Values ◽  
New Equation ◽  
Mixed Oil

Trailing oil is the tail section of contamination in oil pipelines. It is generated in batch transportation, for which one fluid, such as diesel oil follows another fluid, such as gasoline, and it has an effect on the quality of oil. This paper describes our analysis of the formation mechanism of trailing oil in pipelines and our study of the influence of dead-legs on the formation of trailing oil. We found that the oil replacement rate in a dead-leg is exponentially related to the flow speed, and the length of the dead-leg is exponentially related to the replacement time of the oil. To reduce the amount of mixed oil, the main flow speed should be kept at about 1.6 m/s, and the length of the dead-leg should be less than five times the diameter of the main pipe. In our work, the Reynolds time-averaged method is used to simulate turbulence. To obtain contamination-related experimental data, computational fluid dynamics (CFD) software is used to simulate different flow rates and bypass lengths. MATLAB software was used to perform multi-nonlinear regression for the oil substitution time, the length of the bypass, and the flow speed. We determined an equation for calculating the length of the trailing oil contamination produced by the dead-leg. A modified equation for calculating the length of the contamination was obtained by combining the existing equation for calculating the length of the contamination with new factors based on our work. The amounts of contamination predicted by the new equation is closer to the actual contamination amounts than predicted values from other methods suggested by previous scholars.

scholarly journals Calculation method for the amount of contaminant oil during sequential transportation through product oil pipelines

2020 ◽  
Vol 38 (4) ◽  
pp. 1014-1033
Author(s):  
Enbin Liu ◽  
Wensheng Li ◽  
Hongjun Cai ◽  
Weibiao Qiao ◽  
Mohammadamin Azimi
Keyword(s):  
Cross Sections ◽  
Volume Fraction ◽  
Mixing Length ◽  
Refined Oil ◽  
Oil Pipeline ◽  
Actual Operation ◽  
Mixed Oil ◽  
The Relationship ◽  
Replacement Time

A considerable amount of oil contamination is caused by the presence of the trailing oil. This paper aims to simulate and analyze the influences of trailing oil on the quality of oil products in undulating sections. By studying the formation mechanism of mixed oil at inclining pipeline sections and the influences of velocity and oil batches on incline sections, as well as both ups and downs, the correlation is obtained between replacement time of different batches and velocity at various sections. By applying FLUENT 14.5, the maximum time of volume fraction of contaminant oil from 1% to 99% is simulated at cross-sections among different pipeline sections. Aiming at the relationship between oil product replacement time and change time of mixing section volume fraction and flow velocity, the mixing increment of undulating section relative to straight section is obtained. Combining with the empirical mixing length calculation equation, the equation for calculating mixing length considering terrain undulation is obtained. Combined with the actual operation data of Lan-Chengyu’s product oil pipeline, the error of the new mixed oil length calculation equation and actual oil mixing is 0.7966%. Excessive cutting amount of mixed oil will result in the waste of refined oil, and the less cutting amount will cause pollution of refined oil. The new mixed oil length calculation equation can more accurately guide the oil mixing cutting work at the oil station.

‘Do you think you're at the Gresham?’: Accepting Imperfection in ‘The Dead’

2015 ◽  
Vol 10 (2) ◽  
pp. 159-177 ◽  
Author(s):  
Randi Saloman
Keyword(s):  
Sixteenth Century ◽  
Short Story ◽  
Secondary Quality ◽  
The Dead

Dublin's Gresham Hotel, where Gabriel and Gretta Conroy end their evening in Joyce's most famous short story, has a fascinating history. It was founded in 1817 by Thomas Gresham, who began life as a foundling rescued from the steps of London's Royal Exchange and was thereby given the name of the Renaissance statesman who built that exchange. This sixteenth-century Thomas Gresham was even better known, however, for his eponymous ‘Gresham's Law’. Both Gresham's Law and the hotel setting and history enter into and help to shape ‘The Dead’. Questions of value and valuing suggested by Gresham's Law are shown to be more complicated than they initially appear, as they intersect with the various forms of hospitality traced in the story. The ‘secondary’ quality of the famous Dublin hotel (built by the second, unknown Thomas Gresham) underscores – and ultimately redeems – the theme of secondariness that runs through ‘The Dead’.

Additional methods to improve the energy efficiency of oil pipeline transportation

2020 ◽  
Vol 10 (5) ◽  
pp. 558-565
Author(s):  
Marat R. Lukmanov ◽  
◽  
Sergey L. Semin ◽  
Pavel V. Fedorov ◽  
◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Energy Saving ◽  
Pipeline System ◽  
Energy Costs ◽  
Improvement Program ◽  
Oil Pipeline ◽  
Energy Efficiency Improvement ◽  
Oil Transportation ◽  
Pumping Equipment ◽  
Preparatory Work

The challenges of increasing the energy efficiency of the economy as a whole and of certain production sectors in particular are a priority both in our country and abroad. As part of the energy policy of the Russian Federation to reduce the specific energy intensity of enterprises in the oil transportation system, Transneft PJSC developed and implements the energy saving and energy efficiency improvement Program. The application of energy-saving technologies allowed the company to significantly reduce operating costs and emissions of harmful substances. At the same time, further reduction of energy costs is complicated for objective reasons. The objective of this article is to present additional methods to improve the energy efficiency of oil transportation by the example of the organizational structure of Transneft. Possibilities to reduce energy costs in the organization of the operating services, planning and execution of work to eliminate defects and preparatory work for the scheduled shutdown of the pipeline, the use of pumping equipment, including pumps with variable speed drive, the use of various pipelines layouts, changing the volume of oil entering the pipeline system and increase its viscosity.

Assessment of Pomegranate Juice as Antioxidant in Extender on Cauda Epididymis Spermatozoal Quality of Buck at Refrigerated Temperature

2019 ◽  
Vol 15 (02) ◽  
pp. 26-29
Author(s):  
Amarjeet Amarjeet ◽  
C T Khasatiya ◽  
L Chaudhary
Keyword(s):  
Detrimental Effect ◽  
Egg Yolk ◽  
Antioxidant Effect ◽  
Pomegranate Juice ◽  
Antioxidant Additive ◽  
Epididymal Spermatozoa ◽  
The Dead

The present investigation was carried out to study the refrigeration preservation of the cauda epididymal retrieved spermatozoa of buck in Tris egg yolk citrate (TEYC) dilutor containing pomegranate juice as antioxidant additive. The retrieved cauda epididymal spermatozoa extended in TEYC dilutor were studied in five groups by adding different concentration of pomegranate juice as additive (0% as control T1 group and 5%, 10%, 15% and 20% as treatment T2, T3, T4 and T5 groups, respectively) and storing at refrigerated temperature up to 48 hr. The results showed that the control extender had the least dead, abnormal and HOS non-reacted sperm percent among all treatments tested and that with increasing the pomegranate juice concentration in dilutor, the percentage of the dead, abnormal and HOST non-reacted spermatozoa increased significantly. The same trend was observed at all 12 hourly storage intervals indicating its detrimental effect on epididymal sperms of bucks at refrigeration temperature. The dead, abnormal, and HOST non-reacted sperm were significantly and positively interrelated with each other (r = 0.53-0.83). It was concluded that the inclusion of pomegranate juice in TEYC dilutor did not show any beneficial/antioxidant effect on epididymal sperms of buck in fresh or refrigerated semen and in fact all the levels of pomegranate juice (5% to 20%) were detrimental to cauda epididymal spermatozoa of a buck.

Study of Gas Flow in Micronozzles Using an Unstructured DSMC Method

2009 ◽  
Author(s):  
Ehsan Roohi ◽  
Masoud Darbandi ◽  
Vahid Mirjalili
Keyword(s):  
Boundary Layer ◽  
Knudsen Number ◽  
Gas Flow ◽  
Subsonic Flow ◽  
Flow Behavior ◽  
Boundary Layer Separation ◽  
Back Pressure ◽  
Viscous Force ◽  
Dsmc Method ◽  
Wide Range

The current research uses an unstructured direct simulation Monte Carlo (DSMC) method to numerically investigate supersonic and subsonic flow behavior in micro convergent–divergent nozzle over a wide range of rarefied regimes. The current unstructured DSMC solver has been suitably modified via using uniform distribution of particles, employing proper subcell geometry, and benefiting from an advanced molecular tracking algorithm. Using this solver, we study the effects of back pressure, gas/surface interactions (diffuse/specular reflections), and Knudsen number, on the flow field in micronozzles. We show that high viscous force manifesting in boundary layers prevents supersonic flow formation in the divergent section of nozzles as soon as the Knudsen number increases above a moderate magnitude. In order to accurately simulate subsonic flow at the nozzle outlet, it is necessary to add a buffer zone to the end of nozzle. If we apply the back pressure at the outlet, boundary layer separation is observed and a region of backward flow appears inside the boundary layer while the core region of inviscid flow experiences multiple shock-expansion waves. We also show that the wall boundary layer prevents forming shocks in the divergent part. Alternatively, Mach cores appear at the nozzle center followed by bow shocks and an expansion region.

Influence of the speed of casting the dead head on the quality of tube steel

Metallurgist ◽  
1972 ◽  
Vol 16 (12) ◽  
pp. 863-864
Author(s):  
O. N. Suladze ◽  
Sh. D. Dzhaparidze ◽  
A. N. Lomashvili ◽  
Sh. P. Sakvarelidze ◽  
T. A. Tabidze
Keyword(s):  
Tube Steel ◽  
The Dead

scholarly journals OBTAINING OF HYDRO-INSULATION MATERIALS, PENETRANTS AND OTHER DEFICIENT LOW- TONNAGE PRODUCTS FROM PETROLEUM

2020 ◽  
Author(s):  
Guram Khitiri ◽  
Raul Kokilashvili ◽  
Tinatin Gabunia ◽  
Madona Tsurtsumia
Keyword(s):  
Liquid Glass ◽  
Petroleum Products ◽  
The South ◽  
Oil Pipeline ◽  
Insulation Materials ◽  
The Cost

Hydro-insulation of building constructions, different purpose structures is one of the most important and urgent problems of the present day. Currently concrete, ferroconcrete, metal and wooden materials are used for this purpose. Materials of this kind are not produced in the South Caucasian region. Their import, transportation, clearance by the customs and other expenses significantly increase the cost of buildings and makes it unprofitable to use them. Excreted from petroleum products – paraffins and cerezines, petrolatum, luminophores and various purpose binders, can become profitable basis for obtaining of moderm hydroinsulation materials. Their inclusion in modern hydroinsulation compositions will help to increase quality of these materials and to decrease their cost. By mixing of the goudron obtained as a result of rectification of oil pipeline sediments with milled secondary tyre casting, liquid glass, quarz sand and several additives – new hydroinsulation material was obtained.

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