scholarly journals DETERMINATION OF THE THICKNESS OF THE COVER STRUCTURE OF OIL TANKS

Author(s):  
Emil Abdullayev Emil Abdullayev

Oil tanks must meet the requirements of low evaporation losses, as well as durability and longevity. Oil tanks are made of steel and non-metal structures of different materials. Steel oil tanks are small (up to 2000 Pa), high (up to 70,000 Pa) and atmospheric pressure due to the additional pressure in the gas phases. Due to their design, steel oil tanks are vertical cylindrical, horizontal cylindrical, drip-shaped and trench-type. Vertical cylindrical oil tanks are the most common and are mainly conical, spherical, pantone, floating lid. Pantone and floating oil tanks - used to reduce evaporation losses during oil storage. The pantone installed in the oil tank with a capacity of 20,000 m3 consists of a steel floor made of a 4 mm thick layer of steel and a ring with two lids welded along its perimeter at a distance of 2.8 m from each other. These ribs provide rigidity to the pontoon during movement, as well as a reserve swimming position when the middle part of the panto sinks. The annular ribs are connected at a certain distance from each other (up to 1/48 of the circumference) by radial ribs. The annular and radial ribs are welded to the floor of the pantone with a complete seam. Keywords: cover construction, oil storage terminal, oil tanks volume, determination of the coating structure.

Author(s):  
Koyu Satoh ◽  
Naian Liu ◽  
Xiaodong Xie ◽  
Wei Gao

The number of huge oil storage tanks is increasing in the world. If a fire occurs in one of these tanks, it is very difficult to suppress. Additionally, if a fire whirl occurs in an oil tank fire, it is extremely dangerous for firefighters to extinguish the fire. The authors have numerically studied huge fire whirls in a large oil tank depot and predicted the generation of those fire whirls. Here, another study is attempted to clarify the details of huge fire whirl in a large oil tank, using two kinds of fire whirl generation channels in CFD simulations using the software, FDS by NIST. Details of burning rates, velocities of whirling flames, radiative heat flux, heat release rates and whirling cycles are examined, using oil tanks with the diameters of 0.2 to 80 m. In oil tanks with a diameter of 80 m, a tall fire whirl is generated. The height is about 1000 m. In this study of oil tanks fires with small to large diameters, it has been found that fire whirl lengths are about 8 to 11 times of the oil tank diameter. The maximum radiative heat flux due to a fire whirl in 80 m diameter oil tanks exceeds 100 kW/m2. Since the maximum radiation is found at twice the distance of oil tank diameters from the tank centers, adjacent oil tanks may be ignited. This study has also examined a method used to prevent fire whirl generation in huge oil tanks.


2020 ◽  
Vol 319 ◽  
pp. 05001
Author(s):  
C Zhou ◽  
X Cao ◽  
Y Li ◽  
J Wang

The construction of large oil depots has become increasingly important, and oil storage safety also becomes a hot topic. It can be seen from multiple major safety accidents that have occurred in recent years that lightning is considered being one of the main causes of oil tank fires. Through in-depth research on safety issues, we are trying to find a scientific and economical safety management model for oil depots. Most of the objects stored in the oil depots are flammable liquids, and the oil gases which are produced by oil products can easily cause an explosion. A little carelessness may cause casualties and huge economic losses. The main purpose of this research is to design a lightning protection system for fixed roof oil tanks on the ground. By providing a complete design of lightning protection, to show how to ensure the safety level of the oil tank and oil depots, then the authors briefly describe other latest technologies for lightning protection which could be used in the future improvement.


2014 ◽  
Vol 919-921 ◽  
pp. 469-472
Author(s):  
Wen He Wang ◽  
Hai Xia Li ◽  
Zhi Sheng Xu ◽  
Dong Liang

In recent years, the demand of the crude oil is increasing in the world, and the oil storage tanks are also developing larger and larger. Higher requirements of safety for storage tank, especially safety evaluation of the oil tanks in fire environment, was proposed because the oil tank volume is large, as well the oil is volatile, flowing, inflammable and explosive easily. In the paper, the fire process was simulated by the heat treatment for the key position, and the relationship between mechanical property and heating temperature of large tank after fire was obtained. The strength evaluation for large-scale crude oil storage tank after fire was implemented and the result showed that the strength for large crude oil tank was satisfied with requirement.


2018 ◽  
Author(s):  
Yiming Zhao ◽  
Huy van Nguyen ◽  
Louise Male ◽  
Philip Craven ◽  
Benjamin R. Buckley ◽  
...  

<div>Twelve 1,5-disubtituted and fourteen 5-substituted 1,2,3-triazole derivatives bearing diaryl or dialkyl phosphines at the 5-position were synthesised and used as ligands for palladium-catalysed Suzuki-Miyaura cross-coupling reactions. Bulky substrates were tested, and lead-like product formation was demonstrated. The online tool SambVca 2.0 was used to assess steric parameters of ligands and preliminary buried volume determination using XRD obtained data in a small number of cases proved to be informative. Two modelling approaches were compared for the determination of</div><div>the buried volume of ligands where XRD data was not available. An approach with imposed steric restrictions was found to be superior in leading to buried volume determinations that closely correlate with observed reaction conversions. The online tool LLAMA was used to determine lead-likeness of potential Suzuki-Miyaura cross-coupling products, from which ten of the most lead-like were successfully synthesised. Thus, confirming these readily accessible triazole-containing phosphines as highly suitable ligands for reaction screening and optimisation in drug discovery campaigns.</div>


Author(s):  
Vitaly М. Goritsky ◽  
◽  
Georgy R. Shneyderov ◽  
Eugeny P. Studenov ◽  
Olga A. Zadubrovskaya ◽  
...  

Determination of causes of crack-like defects in the heavy plate steel 09Г2С is a crucial task, the solution of which is aimed at improving the mechanical safety of oil storage steel vertical tanks. In order to determine the causes for the formation of a group of crack-like defects oriented towards rolling, revealed during grinding and magnetic inspection of the tank wall surface near the vertical weld, the analysis of the chemical composition and testing of the mechanical properties of heavy plate steel were carried out, including the determination of the anisotropy of impact toughness in the temperature range from +20 to –75 °С, analysis of metal microstructure in the area of defect formation on transversal sections and rolled surface. Impact bending tests of 09Г2С heavy plate steel after controlled rolling in longitudinal and transverse directions showed no anisotropy of impact toughness, as well as high purity of steel as for sulfur and titanium, which at higher content causes impact toughness anisotropy. The revealed features of metal microstructure near the defects made it possible to conclude that the crack-like defects were formed during the rolling of gas bubbles at the stage of preparing semi-finished rolled products for finishing rolling. One of the possible methods to prevent such defects from getting into finished rolled products is the use of automated systems of visual inspection of rolled products in the manufacturing process.


2018 ◽  
Vol 239 ◽  
pp. 06002
Author(s):  
P.V. Chepur ◽  
A.A. Tarasenko ◽  
A.A. Gruchenkova

The problem of the limiting states occurrence in the structures of a vertical steel tank is investigated in this work. To study the SSS of the metal structures of the object, the authors created a numerical model of the RVS-20000 tank in the ANSYS software complex. The model considers the maximum number of elements with their geometry and connections affecting the tank SSS under non-axisymmetric loading, including beyond the elasticity of steel. Dependences between the parameters of intrinsic stiffness of the VST are obtained. The results of the finite element analysis made it possible to develop a technique for assessing the technical condition of the structure with the development of irregular subsidence of the external bottom contour. The proposed technique can be used by both operating and design organizations in making managerial decisions regarding the repair of RVS-20000 subjected to the base subsidence.


2016 ◽  
Vol 12 (S323) ◽  
pp. 65-69 ◽  
Author(s):  
Jorge García-Rojas ◽  
Romano L. M. Corradi ◽  
Henri M. J. Boffin ◽  
Hektor Monteiro ◽  
David Jones ◽  
...  

AbstractThe discrepancy between abundances computed using optical recombination lines (ORLs) and collisionally excited lines (CELs) is a major, unresolved problem with significant implications for the determination of chemical abundances throughout the Universe. In planetary nebulae (PNe), the most common explanation for the discrepancy is that two different gas phases coexist: a hot component with standard metallicity, and a much colder plasma enhanced in heavy elements. This dual nature is not predicted by mass loss theories, and direct observational support for it is still weak. In this work, we present our recent findings that demonstrate that the largest abundance discrepancies are associated with close binary central stars. OSIRIS-GTC tunable filter imaging of the faint O ii ORLs and MUSE-VLT deep 2D spectrophotometry confirm that O ii ORL emission is more centrally concentrated than that of [Oiii] CELs and, therefore, that the abundance discrepancy may be closely linked to binary evolution.


Water ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 601 ◽  
Author(s):  
Dariusz Młyński ◽  
Andrzej Wałęga ◽  
Tomasz Stachura ◽  
Grzegorz Kaczor

The aim of the work was to develop a new empirical model for calculating the peak annual flows of a given frequency of occurrence (QT) in the ungauged catchments of the upper Vistula basin in Poland. The approach to the regionalization of the catchment and the selection of the optimal form of the empirical model are indicated as a novelty of the proposed research. The research was carried out on the basis of observation series of peak annual flows (Qmax) for 41 catchments. The analysis was performed in the following steps: statistical verification of data; estimation of Qmax flows using kernel density estimation; determination of physiographic and meteorological characteristics affecting the Qmax flow volume; determination of the value of dimensionless quantiles for QT flow calculation in the upper Vistula basin; verification of the determined correlation for the calculation of QT flows in the upper Vistula basin. Based on the research we conducted, we found that the following factors have the greatest impact on the formation of flood flows in the upper Vistula basin: the size of catchment area; the height difference in the catchment area; the density of the river network; the soil imperviousness index; and the volume of normal annual precipitation. The verification procedure that we performed made it possible to conclude that the developed empirical model functions correctly.


2020 ◽  
Vol 82 (2) ◽  
pp. 215-224
Author(s):  
V.I. Erofeev ◽  
I.A. Samokhvalov

A numerical study of the survivability of the flange assembly is carried out upon reaching a critical load and in the presence of a defect in one of the design areas, taking into account the calculated values of the aerodynamic coefficients. An experiment is being carried out to determine the values of the wind load acting on the supporting legs of a metal tower. The calculation of the stressstrain state is performed using software system as SCAD Office and IDEA StatiCa 10.0. After calculating the forces in the core model of the structure, a threedimensional plate model of the assembly is formed and prepared for calculation. According to the results of the experiment, a graph was compiled with the values of aerodynamic coefficients, which were used in calculating the stressstrain state of the node. The analysis of the calculation results revealed that in the design (defectfree) state of the structure, the safety factor of the bearing units and elements is 35-40% (equivalent stresses were 165 MPa). If there is a defect in the metal structures of the belt in the region of the flange, the equivalent stresses increase to 247.6 MPa in the region of the cleavage (defective hole), thus, the margin in bearing capacity drops to 0.4%. As a result of the assessment of the survivability of the flange connection, it was revealed that the connection has a high potential survivability, in turn, the flange itself is able to work in the presence of some defects without reducing its bearing capacity to a critical level. The aerodynamic coefficients obtained in this work will determine the wind load on this type of profile and can be used in design calculations of tower structures for wind loads.


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