Vertical Cylindrical Tank Research Articles

BUILDING 3D SURFACES OF LAND STORAGE VERTICAL CYLINDRICAL STEEL TANK USING BICUBIC SPLINE INTERPOLATION

The purpose of this work is to increase the accuracy, quality and information content of geodetic surveys of vertical steel tanks by using modern geodetic equipment and creating algorithms for data processing of these observations. Method. In order to increase the information content of data for straightening, it is proposed to calculate the geometric parameters of vertical steel tanks not only in places where data are directly obtained through instrumental observations, but also at any point of the 3D surface of the tank. The paper describes an algorithm for creating a 3D surface of a tank by bicubic spline interpolation (BSI). Results on the basis of the conducted research, it was established that the developed algorithm could be used and the 3D-surface spatial coordinates were determined. The method of determining the geometric parameters of vertical steel tanks by using BSI is improved. Scientific novelty and practical significance. Bicubic spline interpolation (BSI) was used for the first time. It greatly increases the accuracy and informality of the results of the control. The practical significance is confirmed by the control of the geometric parameters of a vertical cylindrical steel tank with a nominal capacity of 75.000 m3 with a floating roof and a double wall of the LODS “Brody” company.

Stress analysis and strength assessment of ammonia water storage tank

In this paper, a large vertical cylindrical steel ammonia storage tank was numerical simulated. Strength and stability assessment under earthquake load, wind load, internal pressure and dead weight were performed. It is found the strength of the tank meets the strength requirements according to JB4732-1995 Steel Pressure Vessels-Design by Analysis. The tank is in stability even under the compressive stress at the leeward side of cylindrical vessel under the combined wind load and earthquake load.

BEHAVIOUR OF VERTICAL CYLINDRICAL TANK WITH LOCAL WALL IMPERFECTIONS

Design of modern thin-walled metal structures is widely used around the world. In recent decades, more comprehensive research is carried out to investigate the behaviour of various thin-walled structures. Generally, the structure with regular geometry is investigated. In various countries such as USA, Russia, and the European Union issued the standards on regulation of the construction, design and maintenance of thin-walled structures. The actually used period of tanks usually is longer than recommendatory period. Recommendatory maintenance period of metal tanks is 15–20 years. Therefore, for such structures one of the most considerable questions is the residual load bearing capacity beyond the end of the maintenance period. This phase of using of structures is associated with complex investigation and numerical analysis of thin-walled structures. In this paper the load bearing capacity of the steel wall of the existing over-ground vertical cylindrical tank in volume of 5,000 m3 with a single defect and with a few contiguous local defects of the shape is analyzed. Calculations carried out are taking into account all the imperfections of the wall geometry. A major goal of the research – developing a realistic numerical model of the object analyzed, taking into account all the imperfections, determining the wall stress and strain state, exploring the places of extreme points, calculating the residual load bearing capacity of the tank and scrutinizing possible strengthening schemes for defective areas.

An inviscid analysis of the Prandtl azimuthal mass transport during swirl-type sloshing

An inviscid analytical theory of a slow steady liquid mass rotation during the swirl-type sloshing in a vertical circular cylindrical tank with a fairly deep depth is proposed by utilising the asymptotic steady-state wave solution by Faltinsen et al. (J. Fluid Mech., vol. 804, 2016, pp. 608–645). The tank performs a periodic horizontal motion with the forcing frequency close to the lowest natural sloshing frequency. The azimuthal mass transport (first observed in experiments by Prandtl (Z. Angew. Math. Mech., vol. 29(1/2), 1949, pp. 8–9)) is associated with the summarised effect of a vortical Eulerian-mean flow, which, as we show, is governed by the inviscid Craik–Leibovich equation, and an azimuthal non-Eulerian mean. Suggesting the mass-transport velocity tends to zero when approaching the vertical wall (supported by existing experiments) leads to a unique non-trivial solution of the Craik–Leibovich boundary problem and, thereby, gives an analytical expression for the summarised mass-transport velocity within the framework of the inviscid hydrodynamic model. The analytical solution is validated by comparing it with suitable experimental data.

The failure of the floating cover of a vertical cylindrical tank

The failure of the floating cover of a vertical cylindrical tank

Приближённый метод расчёта плавления шугообразного криопродукта в вертикальной цилиндрической емкости

Приближённый метод расчёта плавления шугообразного криопродукта в вертикальной цилиндрической емкости

THE ASSESSEMENT OF THE SCALES AND THE RISK OF THE APPEARANCE TECHNOGENOUS SITUATIONS DURING THE PROCESS OF DEGASING THE STORAGE TANKS OF LIGHT PETROLEUM PRODUCTS

The subject of study in this article is the processes of increasing the level of the environmental and fire safety during the degassing of the vertical cylindrical tanks with the remaints of the light petroleum products. The purpose of this work is concluded in controlling the level of the environmental and fire safety of the territories in the zone of the influence the oil saving objective complexes using the application of the method proposed by U.S. Environmental Protection Agency. The Office of Emergency Management Center, EPA, developed the ALOHA® software product that is used to calculate the distribution of the concentrations during the evaporation of pollutants due to their getting into the oil processing station under different conditions. The task is to assess the level of anthropogenic pressure on the environment, and the influence oil product vapors by the forced decontamination of light oil storage tanks. The methods used here are researching conducted with the use of gas analysis to establish the qualitative and quantitative composition of the gas mixtures at the outlet of the tanks, using the modern test equipment. The following results have been obtained. Due to the researching, the methodology for calculating and forecasting the level of the technogenic load on the atmospheric air by modeling and forecasting the zones of the active pollution by emissions of the vapor-air hydrocarbon mixtures has been developed further. The conclusions. On the basis of the conducted studies, an active contamination zone was determined when performing forced degassing with the air supply, which was carried out using the traditional method, using software for modeling dispersion of pollutants. It has been established that by the forced ventilation of RVS-5000 reservoir, 1.5 tons of the vapor-air mixture get into the natural environment. Using the ALOHA® software product, the hazardous area was estimated, and the area of possible explosion of the gasoline vapors during the natural degassing of the tanks with the storage of light oil products. The size of the zone of the strong toxic influences on the population reaches1.2 km, it was calculated for the given initial conditions, the zone of the fire danger is80 m, the explosion zone does not exceed13 m.

Uneven Base Sediment Influence and Environment Temperature Changes on the Intensely Strained State Tank Wall

This paper describes the possibility of taking into account additional forces caused by temperature operating fluctuations and uneven base sediments on permafrost grounds based on the analysis of the branch pipe welded joints stress state with a wall in vertical cylindrical tanks and the stress intensity factor calculations.

Improving proposals for design standards of vertical cylindrical steel tanks for oil and oil products storage

The calculation of subsidence points along the contour and in the center of the tank bottom is complicated in the case of erosion on inhomogeneous, subsidence, damaged soils, mules, flooded and seismically dangerous areas. The article analyzes the most dangerous geological phenomena, processes and complicated geotechnical conditions for the territory of Ukraine. The method of an artificial base arrangement with improved properties due to vertical reinforcement by soil cement elements is considered. Techno-economic comparison of the proposed variant with the usual pile variant of foundations (subsidence soils, estimated seismic intensity of 9 points) has been carried out. Probabilistic analysis of the artificial base has been carried out and the corellation between the probability of its failure from the percentage of reinforcement has been determined.

An evaluation of additional criteria for assessing the condition of oil terminal tanks with the aim of extending safe service life - Part 1

This article examines topical issues regarding the monitoring technical condition for vertical cylindrical tanks of oil terminals. It presents an analysis of standards in the Russian Federation and abroad for tank technical diagnostics in the area of strength calculations when determining the remaining lifetime of tank structures. The possibility of using laser scanning technology to evaluate tank technical condition is also demonstrated. Standards in the Russian Federation, unlike abroad, recommend carrying out strength calculations of tank structures using finite element methods and 3D models. These 3D models correspond to the real geometric shapes of structures, which are mapped using discrete geodesic surveying. Surface laser scanning technologies (SLS) have been in use in both domestic and foreign practice for over 12 years. They enable the geometric parameters of structures to be checked with high accuracy during operation. The issue. SLS technologies have not previously been used in the Russian Federation to develop computer models of tank structures for strength calculations and measurements using finite element methods

CFD Modelling of Vertical LNG Tanks Adopted in Heavy Trucks Refuelling Stations

In the present study, a Computational Fluid Dynamics (CFD) model was set up to analyse the dynamic behaviour of LNG (Liquefied Natural Gas) tanks adopted in heavy trucks refuelling stations in normal operating conditions or during process upsets. The CFD model was based on the Volume-Of-Fluid (VOF) method to simulate the transient behaviour of a multi-phase flow in a 100 m3 vertical cylindrical tank. The model first considered a fully insulated vessel, and subsequently it was modified to take into account possible damages of the insulation layer, this being a critical upset scenario. The CFD model allowed predicting the dynamic pressure build up in the damaged tank, thus obtaining key indications for the evaluation of the vessel mechanical resistance and set up of safety measures. The model also provided the prediction of vapor temperature with respect to time and external heat source, that is a key issue to assess the effectiveness of the thermal insulation.

Experimental and Numerical Study of Heat Transfer Process of Chilled Water Storage Tank

Cool thermal energy storage using thermal stratification becomes one of the widespread applications because of the ability to shift the electrical cooling loads from on-peak to off-peak periods and significantly contributes to reducing the capacity of the refrigeration system and operating costs. Seven flow rate tests varying from 1.5 to 7.5 l/min for charging cycle were performed on small-scale vertical cylindrical storage tank equipped with three primary inlet diffusers, an elbow, two-ring linear and radial circular diffusers. The storage tank with inlet diffusers was assessed using temperature distributions and performance measures including thermocline thickness(ht), the half-cycle figure of merit ( ) and equivalent lost tank height (ELH). Commercial finite volume code was used to predict temperature distributions in a stratified water tank model, temperature data acquired from experimental tests and simulation models were compared for validation purpose. The results suggested that the storage tank with two-ring linear circular diffuser produced better performance and higher stratification than two-ring radial circular diffuser for various flow rates by 1.4% , 20.6% ELH and 10.6% ht, and much better than an elbow diffuser by 1.7% , 24% ELH and 31.1% ht, furthermore, the degree of mixing was affected essentially the flow velocity which in turn causes an increase or decrease in thermocline thickness. Temperature distributions obtained from finite volume model are found to be in very close agreement with those obtained experimentally.

Study of 3D sloshing in a vertical cylindrical tank

Moving liquid-gas interfaces appear frequently in both natural processes and engineering applications. In the case of partially filled tanks, for instance, the accurate description of the free surface transient behavior during transportation or earthquakes is of paramount importance for structural stability analyses. This work presents new experimental data of sloshing at laboratory scale in a vertical cylindrical tank with different filling levels, along with numerical simulations of selected cases using an open source finite volume application. Maximum and minimum experimental wave heights, measured with ultrasonic sensors, are reported for several non-resonant cases during the periodic steady state regime, along with snapshots of a video recorded near-resonance case. For the numerical simulations, a suitable mesh was designed based on a mesh convergence analysis focused on the simulated velocity profiles at the tank wall. A slight nonlinear behavior is detected in the experimental wave patterns, expressed as non-symmetrical minimum and maximum wave heights. The near-resonance case, in turn, shows a highly three-dimensional behavior of the free surface and a rotational effect. The numerical results obtained for the non-resonant cases show good overall agreement with the experiments, although the non-linear behavior is not accurately modelled. The evolution of the highly distorted free surface in the near-resonance case is well captured by the simulation, along with the observed rotational effect.

Experimental study on the seismic response of liquid storage tanks with Sliding Concave Bearings

It is known that, earthquakes have caused severe damages to a large number of industrial facilities, mainly storage tanks with extremely serious economic and environmental implications. Thus, it is extremely importance to use techniques for reducing the seismic vulnerability of such structures. Seismic base isolation as seismic protection technology is already known and its development continues to grow. The present paper focuses on the seismic performance of broad and slender atmospheric storage steel tanks base isolated by Sliding Concave Bearings (SCB). The performance study carried out through shaking table tests on a vertical cylindrical steel tank model allowed to determine quantitatively the efficiency of the SCB by analyzing two structural parameters: (a) sloshing height and (b) base shear force. Six real ground motions with different characteristics were considered. Results show the effectiveness of SCB in reducing the base shear force values for all studied cases without significantly affecting the sloshing displacements when compared with fixed-base support.

Numerical analysis of stress-strain state of vertical cylindrical oil tanks with dents

Numerical analysis of stress-strain state of vertical cylindrical oil tanks with dents

Capillary hysteresis in sloshing dynamics: a weakly nonlinear analysis

The sloshing of water waves in a vertical cylindrical tank is an archetypal damped oscillator in fluid mechanics. The wave frequency is traditionally derived in the potential flow limit (Lamb, Hydrodynamics, Cambridge University Press, 1932), and the damping rate results from the combined effects of the viscous dissipation at the wall, in the bulk and at the free surface (Case & Parkinson, J. Fluid Mech., vol. 2, 1957, pp. 172–184). Still, the classic theoretical prediction accounting for these effects significantly underestimates the damping rate when compared to careful laboratory experiments (Cocciaro et al., J. Fluid Mech., vol. 246, 1993, pp. 43–66). Specifically, theory provides a unique value for the damping rate, while experiments reveal that the damping increases as the sloshing amplitude decreases. Here, we investigate theoretically the effects of capillarity at the contact line on the decay time of capillary–gravity waves. To this end, we marry a model for the inviscid waves to a nonlinear empiric law for the contact line that incorporates contact angle hysteresis. The resulting system of equations is solved by means of a weakly nonlinear analysis using the method of multiple scales. Capillary effects have a dramatic influence on the calculated damping rate, especially when the sloshing amplitude gets small: this nonlinear interfacial term increases in the limit of zero wave amplitude. In contrast to viscous damping, where the wave motion decays exponentially, the contact angle hysteresis can act as Coulomb solid friction, thus yielding the arrest of the contact line in a finite time.

ПРОСТОРОВО-ЧАСОВА ЕВОЛЮЦІЯ НЕЛІНІЙНИХ ПОВЕРХНЕВИХ ЗБУРЕНЬ УЩІЛЬНЮВАНОЇ БЕТОННОЇ СУМІШІ У ВЕРТИКАЛЬНО ВІБРУЮЧОМУ ЦИЛІНДРИЧНОМУ БАКУ ПРИ ЙОГО ІДЕАЛЬНОМУ ЗБУДЖЕННІ

Обґрунтований метод моделювання та аналізу просторово-часової еволюції нелінійних поверхневих збуджень бетонної суміші, що ущільнюється, у вертикально вібруючому циліндричному баку при його ідеальному збудженні. У межах запропонованого методу й прийнятих припущень отримане стандартне нелінійне еволюційне рівняння у частинних похідних, яке дозволяє здійснювати детальний аналіз виникаючих нелінійних хвиле утворень у досліджуваній системі. У більшості випадків цим рівнянням є нелінійне рівняння Шредінгера з дисипацією. Проведений всебічний аналіз отриманих аналітичних розв’язків вказаного рівняння для випадків: а) вільного без демпфування руху бетонної суміші; б) вільного руху бетонної суміші з демпфуванням; в) квазісолітонного руху бетонної суміші в умовах компенсації демпфування і наявності привантаження на поверхні циліндричного бака. Знайдені аналітичні розв’язки нелінійного еволюційного рівняння періодичного типу (т.з. кноїдальні хвилі) описуються еліптичними функціями Якобі чи функціями Вейєрштрасса. Квазісолітонні розв’язки мають у своєму знаменнику типову функцію для солітонних (уособлених) хвиль – гіперболічний косинус, тобто пропорціональні гіперболічному секансу. Застосування привантаження спеціальної форми (радіально ребристої) при віброформуванні виробів з бетонної суміші дозволяє збуджувати квазісолітон на поверхні рідини/суміші, що ущільнюється, й чітко визначити всі фізичні константи (амплітуду, швидкість, початкову фазу коливань), які фігурують у розв’язку еволюційного рівняння, виникаючих квазісолітонних хвилеутворень. Результати даного дослідження можуть бути у подальшому використані для уточнення й вдосконалення існуючих інженерних методів розрахунку енергосилових характеристик вібромашин для ущільнення бетонних і будівельних сумішей як на стадіях їх проектування/конструювання, так і у режимах реальної експлуатації.

Нормативное обеспечение безопасности стальных вертикальных цилиндрических резервуаров для нефти и нефтепродуктов

Нормативное обеспечение безопасности стальных вертикальных цилиндрических резервуаров для нефти и нефтепродуктов

Numerical analysis of the cylindrical rigidity of the vertical steel tank shell

The paper deals with the study of rigidity of a vertical steel cylindrical tank and its structural elements with the development of inhomogeneous subsidence in ANSYS software complex. The limiting case is considered in this paper: a complete absence of a base sector that varies along an arc of a circle. The subsidence zone is modeled by the parameter n. A finite-element model of vertical 20000 m3 steel tank has been created, taking into account all structural elements of tank metal structures, including the support ring, beam frame and roof sheets. Various combinations of vertical steel tank loading are analyzed. For operational loads, the most unfavorable combination is considered. Calculations were performed for the filled and emptied tank. Values of the maximum possible deformations of the outer contour of the bottom are obtained with the development of inhomogeneous base subsidence for the given tank size. The obtained parameters of intrinsic rigidity (deformability) of vertical steel tank can be used in the development of new regulatory and technical documentation for tanks.

Thermal Storage Characteristics of the Vertical Cylindrical Water Tank

AbstractThis study conducts experimental and numerical investigations on the thermal storage characteristics of the vertical cylindrical water tank in the heat preservation process. A new experimen...