Tank Shell Research Articles

From CAD model to WAM component: implementation of complex geometries using the example of a hydrogen tank.

Abstract Hydrogen is expected to play a decisive role on the way to climate neutral transportation. This paper explores the innovative use of wire arc Directed Energy Deposition (waDED) in the manufacturing of a double walled, vacuum insulated liquid hydrogen storage tank. The study demonstrates the feasibility of the waDED process for the manufacturing of tank shells and furthermore the integration of heat exchanger channels into tank shells. Key findings include the development of a suitable process chain with integration of multiple features to ease manufacturing. However, challenges such as thermal shrinkage of the shells as well as geometrical deviations of the outer tank heat exchanger are encountered. Future research will focus on improvements in the process reliability with regards to geometric accuracy as well as in-depth testing under liquid hydrogen condition.

Critical diameter for a single-tank molten salt storage – Parametric study on structural tank design

Molten salt thermal energy storage (TES) is a cost-effective option for grid-connected storage in both concentrating solar power (CSP) plants and retrofitted thermal power plants in a multimegawatt scale. Current systems use two tanks (hot and cold), but future systems may use a single tank with a transient temperature profile (hot in the top and cold in the bottom) to reduce costs and space. However, the structural and mechanical design of large-scale molten salt single-tank storages at 560 °C has not been fully explored, and the impact of increasing the operating temperature to 620 °C is still uncertain. The challenge presented by a single tank is the existence of a temperature profile that results in a varying thermal expansion of the tank shell along its height. In the case of larger tanks, this discrepancy can reach a magnitude of centimeters, which in turn gives rise to bending moments. To the best of our knowledge, this study addresses the issue of bending stresses in large-sized high-temperature tanks with thermal stratification for the first time. The modelling approach is applied to single-tank CSP TES systems as a case study to evaluate the constraints imposed by tank size and wall thickness.With the help of experimentally validated numerical methods, it is revealed that a low thermocline thickness can be a limiting factor for large tank diameters. It is shown that the temperature has a major influence on maximum possible tank size: if the operating temperature is raised from 560 °C to 620 °C, the permitted tank diameter is significantly reduced when using the same tank wall material. A possible approach is to use a more heat resistant steel for 620 °C. Results of the parametric study show that designing a single tank below a critical diameter only requires a moderate increase of the wall thickness compared to the two-tank system with constant temperature profiles. Based on this parametric study a formula for the critical tank diameter is developed and presented in this work. The paper concludes with recommendations on how increased wall stresses can be addressed by an appropriate design.

Seismic performance assessment of an existing anchored and a self-anchored liquid storage tank in high seismic regions

This study presents seismic performance of two existing at-grade industrial liquid-storage tanks located in the Eastern part of Marmara region, which is a high seismic region in Turkey. The first tank is self-anchored (unanchored) and has been in service for 44 years, while the other tank is mechanically anchored to a reinforced concrete foundation and has been in service for 50 years. Tanks seismic performance is evaluated using tank time-history earthquake analyses with recorded ground motions scaled for each tank site. The liquid content was included in the developed model using provisions of API 650. Tanks base uplift, sliding on the foundation, tank shell and bottom plate damage, and demand on tank anchorage were determined. The results shows that self-anchored tank has base plate uplift and sliding that are larger than the allowable limits while the mechanically anchored tank has acceptable seismic performance with potential seismic damage of tank anchorage system. The findings of this study contribute valuable insight into the seismic performance of existing liquid storage tanks in the region under new seismic regulations and increased seismic loads than those used for their design.

Research on welding defect examination technique based on phased array ultrasonic for high voltage transformer oil tank welds

Oil tank of high voltage transformer plates. During welding and operation, defects such as incomplete fusion, incomplete penetration , air holes and cracks may be produced which influence the integrity and density of the welds and the whole tank. In order to test the integrity of the shell weld of high-pressure transformer box and ensure no leakage of transformer oil, the phased array testing technology is used to detect the defects of the butt weld of the transformer oil tank. The characteristics of weld defect detection under the condition of incomplete penetration were studied, and the sound beam accessibility, process selection principle and probe selection principle were theoretically analyzed. The test tests were carried out on the artificial samples of the butt weld of the transformer oil tank plate. The results show that the phased array can effectively detect the defects in the weld of transformer tank shell under the condition of incomplete welding, and the imaging results are intuitive and easy to judge, which can effectively evaluate the integrity of transformer tank weld. During the process selection, the probe-wedge combination with appropriate front distance and detection Angle should be selected according to the wall thickness, weld penetration depth and crown width of the transformer oil tank. During defects judgment, the interference of structure echo wave and incomplete penetration area should be considered. The assistant defect positioning analysis based on incomplete penetration is also suggested.

Stability Analysis of HSD Tank Against Dynamic Response

The existing HSD tank F-6302 has suffered damage in the form of corrosion which has caused the plate thickness to decrease. Developments in analysis methods and tank design standards have an effect on determining the stable capacity of the tank, so it is suspected that this tank is unstable. This study aims to analyze the stability of the existing HSD tank F-6302 to seismic response. The analysis was carried out by collecting structural property data of the tank, modelling the tank in FEM with a combination approach of finite element model and auxiliary mass, and evaluating the stability value of the tank using the equation issued by API 650:2020 to assess whether the tank is stable or not. The analysis results confirmed that the tank was unstable to earthquake loading. This is shown by the tank anchorage ratio values of 2.59 for the empty condition and 3.21 for the full condition. Both are greater than the stable limit value of 1.54. In the future, it is recommended to perform tank shell design and anchorage design on the tank.

К вопросам транспортировки гептила железнодорожным транспортом

Purpose: To estimate the properties of heptyl and its effect on the human body and the environment. To provide an overview of the sphere of heptyl application and the features of its transportation by rail. To consider the structural features of the model 15-629 tank car and to perform a calculation to select the optimal crosssectional area for the inlet opening of the relief valve to enhance safety during the transportation of heptyl by the model 15-629 tank car. Methods: To calculate the inner and outer surface areas of the tank shell using the technical characteristics of the six-axis multi-unit tank-car of model 15-629. Next, we will calculate the mass air flow rate through the inlet relief valve and determine the heat transfer occurring due to the external heat dissipation from the tank shell into the surrounding environment. These data are necessary to estimate the equivalent diameter of the inlet relief valve orifice. Results: Thanks to the calculations performed, a more suitable diameter of the inlet safety valve orifice has been determined. This will ensure a safer transportation of highly toxic liquid rocket fuel components used in both Russian launch vehicles (“Kosmos”, “Cyclone”, “Proton”) and international ones (such as American “Titan” rockets, French launch vehicles of the “Ariane”, Chinese rockets of the “Long March” family, and others). Practical significance: Hydrazine-based propellants are more energy-efficient compared to hydrocarbon-based propellants, which has led to an increased usage of Unsymmetrical Dimethylhydrazine (UDMH) in recent years. Due to the rapid growth of space industry, the volume of heptyl transportation by railway has been increasing. In order to prevent technological disasters, calculations have been conducted to determine the diameter of the inlet relief valve to minimize depressurization of the tank car, regardless of temperature conditions.

Remaining service time prediction for corroded shell of a steel tank used for liquid petroleum fuels storage

A numerical example allowing for effective forecasting of the remaining service time for corroded steel shell of a tank used to store liquid petroleum fuels is presented. This time is interpreted here as a period of time counted from the moment of an obligatory tank shell inspection to the moment of the anticipated shell failure understood as the loss of the capacity to safely resist the loads applied to it. Reaching the limit value of failure probability, i.e. the highest probability of failure acceptable to the tank user, is in this approach a determinant of such failure. The detailed considerations pertain to a typical on-the-ground storage tank equipped with a floating roof, located in one of fuel depots in the south of Poland. The forecast has been prepared based on measurements of the random thickness of tank shell weakened by corrosion and measured after 27 years of service time. In the recommended analysis fully probabilistic computational procedures have been applied. This led to a more credible and less conservative service time assessment than the one usually determined via the traditional standard approach. For comparative purposes qualitatively different but formally corresponding safety measures have been applied to describe the obtained results.

The Static and Dynamic Behavior of Steel Storage Tanks over Different Types of Clay Soil

Steel storage tanks are widely used in different fields. Most of these tanks contain hazardous materials, which may lead to disasters and environmental damage for any design errors. There are many reasons which cause the failure of these tanks such as excessive base plate settlement, shear failure of soil, liquid sloshing, and buckling of the tank shell. In this study, five models of above-ground steel storage tanks resting over different types of clay soils (medium-stiff clay, stiff clay, and very stiff clay soils) are analyzed using the finite element program ADINA under the effect of static and dynamic loading. The soil underneath the tank is truly simulated using a 3D solid (porous media) element and the used material model is the Cam-clay soil model. The fluid in the tank is modeled depending on the Navier–Stokes fluid equation. Moreover, the earthquake record used in this analysis is the horizontal component of the Loma Prieta Earthquake. The analyzed tanks are circular steel tanks with the same height (10 m) and different diameters (ranging from 15 m to 40 m). The soil under the tanks has a noticeable effect on the dynamic behavior of the studied tanks. The tanks resting over the medium-stiff clay (the weakest soil) give a lower permanent settlement after the earthquake because of its low elastic modulus which leads to the absorption of the earthquake waves in comparison to the other types of soil. There are 29.6% and 35.6% increases in the peak dynamic stresses under the tanks in the cases of stiff clay and very stiff clay soils, respectively. The maximum values of the dynamic vertical stresses occur at a time around 13.02 s, which is close to the peak ground acceleration of the earthquake.

Some thoughts on integrity management of mounded storage tanks

In the domestic petrochemical industry, mounded storage tanks (MSTs) are widely used to store hazardous chemicals. The shell of the mounded storage tank is completely covered by soil to effectively mitigate the effect of the external environment and prevent thermal-expansion-induced explosion of the stored material. Because mounded storage tanks are mostly underground, they are highly safe, provide effective land utilization, and are highly energy efficient. Furthermore, the impact radius in case of an explosion is less than that of aboveground tanks. However, adequate regulations and standards for safety management are yet to be established. This study established a novel method for the integrity management of mounded storage tanks through database construction, risk assessment, applicability monitoring, and testing. At the same time, the risk assessment method for mounded storage tank characteristics is constructed for the first time.

Use of interpolation methods for modeling the stress-strain state of operated oil storage tanks

The aim of the research is the comparison of two approaches for computer modeling of the stress-strain state of thin-walled shells of engineering structures, considering the imperfections of the geometric shapes arising due to their operation. The object of the study is the operated steel vertical cylindrical reservoir with imperfections of the geometric shape intended for storage of petroleum products. The first, so-called classical, approach provides geometric modeling of the surface of the tank's shell with the subsequent import of the geometric model into one of the systems of finite element analysis to calculate the stress-strain state of the structure and determine its technical condition, and the possibility of further operation. The geometric modeling of the shell surface with imperfections was performed using a two-dimensional interpolation method based on the 1st order smoothness outlines implemented in the point calculus. The calculation of the stress-strain state of the shell was carried out in the SCAD Office computer complex, taking into account geometric and structural non-linearity on the basis of the octahedral tangential stress theory. The second approach assumes modeling of an array of functions of vertical deflection of the tank wall by means of interpolation, solution of an array of differential equations of the elastic cylindrical shell under axisymmetric loading, improved by introduction of vertical deflection functions of the wall, followed by two-dimensional interpolation and analysis of the deformed state of the shell based on displacements arising in the tank wall from the hydrostatic load. As a result of the effective use of two-dimensional interpolation in the process of implementing the second approach, it was possible to achieve a significant increase in the speed of the numerical solution while maintaining sufficient accuracy for engineering calculations.

Three-Dimensional Stress-Strain State Analysis of the Bimetallic Launch Vehicle Propellant Tank Shell

Three-Dimensional Stress-Strain State Analysis of the Bimetallic Launch Vehicle Propellant Tank Shell

Strength of safety arcs of tanks for the carriage of dangerous goods by road

The article contains recommendations on the choice of the design version of the safety arcs of the drain, dispensing equipment, proving fits and input relief valve of tank shells for transportation of dangerous goods. The conclusions contain proposals for further ways of action for domestic manufacturers and inspection bodies of tanks and equipment for the transport of dangerous goods. Keywords: dangerous goods, road safety, ADR, tank trucks

Thermodynamic and heat transfer models for refueling hydrogen vehicles: Formulation, validation and application

Compression is currently the preferred storage technology for hydrogen vehicles due to its quick refueling process and relatively simple design. However, the temperature rise associated with fast filling must be controlled to ensure its safe operation. This article discusses general heat transfer models based on the mass and energy balance equations for the refueling process of the compressed hydrogen storage tank. Depending on the way of treating the geometric structure of the storage tank, three general lumped parameter models of single-zone (hydrogen), dual-zone (hydrogen and tank wall) and triple-zone (hydrogen, tank wall liner and shell) are built. The general single-zone and dual-zone models are reduced to some special cases which have been published. Under adiabatic and diathermic conditions, four models, including single-zone, dual-zone single-temperature (hydrogen temperature), dual-zone dual-temperature (hydrogen and tank wall temperatures) and triple-zone triple-temperature (hydrogen, tank wall liner and tank wall shell temperatures), are implemented using Matlab/Simulink™ to simulate the hydrogen refueling process under corresponding conditions. Analytical solutions of single-zone and dual-zone lumped parameter models are derived. The temperature rises of the compressed hydrogen storage tank are described by comparing the analytical solution with the numerical solution. The proposed general models were applied to estimate the final hydrogen temperature and mass, the SOC, the refueling time, and the precooling hydrogen temperature, reviewed and summarized in this article. The analytical solutions of the heat transfer during hydrogen refueling can provide theoretical guidance for improving the refueling efficiency and enhancing refueling safety.

Comparison study on three ice storage equipments using micro-tube heat exchanger for cold chain logistics

ABSTRACT Freezing efficiency was the main factor affecting the efficiency of cold chain logistics and transportation. To further the ice storage performance, three mathematical models of the ice storage equipments were established to explore the influence of the number and the diameter of the tubes on the freezing time, heat flux, and natural convection by analyzing the distribution of the ice fraction and velocity. The results showed that the total freezing time of Type II and Type III, which were arranged the micro-tube, were 76.42 min and 137.50 min, which was more than 90% less than that of type I. Due to a ring cavity of water appearing near the shell of the ice storage tank increased the water natural convection, the freezing time required to increase the ice fraction by 0.05 gradually increased especially with the ice fraction greater than 0.95. To better evaluate the ice storage performance, the freezing efficiency was introduced. The freezing efficiency of Type II and Type III was lower than that of Type I by more than 2.24% and 2.14%, respectively, for the ice fraction range of 0.75 ~ 1. Given the freezing time and ice storage efficiency, it could be found that using type II and making the ice storage rate reach 0.95 could shorten the freezing time and improve the ice storage efficiency.

Analysis of the corrosion rate and remaining life of the B3 waste transport roll-off tank composed of 316L stainless steel

Corrosion has eroded the shell and head of the roll-off tank used to carry B3 waste. This influence will effect on the functioning of the waste containment tanks, as well as the general safety of the public. The goal of this study was to examine the viability of employing a roll off tank by completing a visual inspection and engineering calculations using ASME VIII and API 510 standards to determine the corrosion rate and remaining life in the roll-off tank. This study employs a quantitative approach. Tank design data was acquired using SA-240/G316L material with an initial shell and head thickness of 6 mm and an actual thickness of 5.45 mm shell and 5.50 mm head. The corrosion rate and remaining life analysis yielded a Thickness Required shell value of 4.33 mm and a head value of 4.33 mm, with a shell and head Corrosion Rate value of 0.04 mpy, a Maximum Allowable Working Pressure (MAWP) value of shell and head of 0.63 Bar, and a shell and head remaining life value of 28 years and 30 years, respectively. It may be established that the roll-off tank is still operationally viable. Maintenance and testing regularly to improve roll-off tank performance

RISK-BASED INSPECTION OF CRUDE AND REFINED OIL STORAGE TANK IN INDONESIA REFINERY PLANT

A storage tank, which is used to store oil, is important and high-risk equipment that requires attention to its safety aspects. As a preventive measure, the government requires inspections of all storage tanks, either on a regular basis (every four years) or based on risk assessment. This safety study aims to create an inspection plan for the storage tanks at the oil refinery using the risk-based inspection (RBI) method. The RBI method in this study adopts API RP 581, Third Edition, 2016. Risk analysis is carried out in stages, including collecting technical data on the tanks, determining failure mechanisms, conducting risk analysis, and finally creating an inspection interval and method. Technical data was collected and studied for 29 storage tanks designed according to the API 650 standard. The determined failure mechanisms for the storage tank shell are atmospheric corrosion, general corrosion, and corrosion under insulation. The results of the risk analysis showed that all tanks have a medium risk, with 16 units in category 3C and 13 units in category 2C. The planned inspection methods are visual inspection, UT thickness or flaw thickness, and CUI, with most inspection intervals reaching 10 years. Based on this study, it is concluded that risk-based inspection (RBI) is more effective and efficient than the specific time interval inspection method (every 4 years).

The effect of the composition of the hydrocarbon mixture on the transfer in thermoplastic polyurethanes

The transfer of mixtures of hexane and toluene in thermoplastic polyurethanes used in the production of tanks for temporary storage and transportation of liquid fuels has been investigated. The standard methodology for estimating the diffusion permeability of polymers is not the basis for modeling the natural loss of fuels during storage. A model for estimating natural loss is proposed, the equations of which describe the linear dependences of the decrease in the mass of fuels in tanks in the coordinate of a conditional time equal to the square root of time. The efficiency of the proposed model depends on the composition of the hexane-toluene mixture, since the composition of the mixture affects the limiting stage of the process, which determines the dependence of the natural loss either on the diffusion rate of the fuel in the tank shell, or on the volatilization of the released fuel from the outer surface of the tank.

MODELLING AND FINITE ELEMENT ANALYSIS OF COMPOSITE PRESSURE VESSEL

Pressure vessel chambers have wide capacities in warm and thermal energy stations, cycle and substance enterprises, in house and sea profundities, and liquid stockpile strategies in ventures. Spot on plan follow is admissible strain for weld power communicated as weld proficiency. Proficiency is illustrated as the proportion of longitudinal (pivotal) power of a welded joint to the longitudinal power of line or tank shell. In this proposal, the strain vessel is planned by the weld productivity and dissected for its solidarity using limited component examination application ANSYS. Numerical relationships will most likely be respected for the plan of tension vessel whose plan boundaries are designated through an association as per the ideal weld productivity. Displaying will be refined in CATIA. Investigation will be done in ANSYS on the strain vessel with various composite materials. In this task, static investigation is to decide the pressure, misshapening and strain. Exhaustioninvestigation is to decide the life, harm and wellbeingvariable of the tension vessel utilizing EN 32 Steel, Carbon fiber and Eglass fiber materials.Heat examination is to decide the temperature dissemination and hotness move rate per unit space of the tension vessel utilizing EN 32 Steel, Carbon fiber and E-glass fiber materials. Straight layer investigation is to decide the pressure, misshapening and resist various layers stacking like 3, 6, 9 and 12 layers.

Analiza udarne žilavosti i kritičnog faktora intenziteta napona KIc kod feritno-austenitnih zavarenih spojeva različitim unosom toplote

Introduction/purpose: Constructions always have several critical points that can be sources of possible defects. All these critical places must be taken into account in safety assessment where the most unfavorable exploitation factors are considered and the local safety of a joint is assessed. Today, joints of various compositions are becoming more frequent in metal constructions. Due to the requirements of economy and ecology, welded joints of microalloyed ferritic steels with high-alloyed austenitic steels are increasingly encountered during the construction of power plants, chemical facilities, etc. Tests of such welded joints have been performed on tanks for oil derivatives, where parts of the tank shell are made of microalloyed ferritic steel and the roof structure is made of high-alloyed austenitic steel. Methods: In the paper, an experimental analysis of crack propagation in an austenitic-ferritic welded joint was performed. The welding was performed by the MIG welding process with two different heat inputs, and the same filler material MIG 18/8/6 was used. Two types of welded plates were tested. the characteristics of the base, filler and auxiliary materials and welding 16 technologies are given. Notched test specimens with an initiated crack-type fracture were made in order to determine the impact properties and fracture mechanics parameters. The results: The research carried out within this study aimed to compare the obtained results of the impact toughness and fracture toughness at flat deformation in a ferrite-austenitic welded joint. An evaluation of the results obtained during the testing of the experimental plates welded with different amounts of heat input is also given. Conclusion: These test results established the dependence of the geometry of a propagating crack and the stress conditions for further crack propagation. It is possible to determine the values of the parameters that describe the behavior of the material, both in linear-elastic and in elastoplastic fracture mechanics.

Wind Buckling Analysis of a Large-Scale Open-Topped Steel Tank with Harmonic Settlement-Induced Imperfection

In this study, the wind buckling capacity of an open-topped steel tank with harmonic settlement-induced imperfection is numerically investigated. Although the single effect of the wind load or differential settlement on the open-topped steel tanks is widely studied, the interaction of the two loads to the tank shell is scarcely examined. The prototype of a 100,000 m3 open-topped steel tank with a floating roof is selected, and the harmonic settlements (wave numbers n = 2, 3, and 4) and the wind profile considering internal pressure (EN 1993-4-1) are applied. Firstly, the finite element model is established and validated by the replication of peer-reviewed research. Then, the wind buckling analysis of the tank shell with harmonic settlement-induced imperfection is studied. Next, the effects of the harmonic settlement-induced imperfection (HSII) and the wind attack angle (WAA) on the wind buckling capacity are discussed. The results show that the effect of the HSII on the wind buckling capacity is complex. When the wind attack angle is the case of β=0°, the wind load capacities (λcig) with HSIIs decrease to 73.4% (wave number n=2), 37.5% (wave number n=3) and 41.3% (wave number n=4) of the non-settlement wind load capacity (λcg). Given that the case of β=0° is the basis, when the harmonic settlement level is low, such as settlement load No.1 and No.2, the biggest increase of wind buckling capacity is less than 20% with an exception; when the harmonic settlement level is high, such as settlement load No.3, No.4 and No.5, the biggest increase of wind buckling capacity is more than 40%, with a few exceptions.