Containment Shell Research Articles

Structural behaviour of single-deck floating roof tanks subject to seismic loading

During a seismic event, fluid storage tanks are subject to sloshing phenomena; their effect on the structural components of the tanks is one of the main aspects to be considered during the design. The movement in successive modal forms of the roof-fluid system determined by the earthquake can cause severe damage to both the containment shell and the floating roof. The fluid-structure interaction imposes extremely complex out-of-plane deformation fields, mainly in the presence of floating roofs with lower flexible resistance. Such deformations can cause severe structural damage and subsequent catastrophic events such as those experienced in the past in Japan and Turkey. In fact, recently recorded earthquakes in Japan and Turkey, characterized by oscillation periods between 3 and 8 sec (long-period ground motion), compatible with the natural first and second slosh frequencies of the fluid-structure system, led to conspicuous problems of instability failure with the consequent sinking of the floating roof. These events dictated a new starting point for the research into the seismic behaviour of roof-fluid-tank systems.

Improving the shear resistance of ground technological quarry roads on loosely-bound subgrades

The study aims to solve the urgent problem of strengthening the subgrade of roads for heavy-duty vehicles. In the case of a limited road service life, it appears economically unfeasible to provide a strong cement-concrete subgrade. This case requires a solution maximizing the use of both local materials and production wastes, available in the work area. In order to perform calculations of stresses, arising at a great depth in the subgrade of the technological road under the influence of heavy-duty vehicle wheels, it is necessary to use appropriate mathematical models. In the present study, the calculations were carried out using a software application that implements the method of discrete elements. Using this method, stresses in highly inhomogeneous granular media can be calculated using the first[1]principle approach. The design of road structural layers suggests the use of geocontainers, made of used polypropylene big bags at the subgrade, which, due to their large size, have a greater shear resistance when filled with any soil mixture. The durability of the polypropylene fabric in the roadbed can reach several decades. The main task of the study was to calculate the protective layer of alternated crushed stone, clay soil, and polypropylene fabric. The thickness of layers was selected such that the tensile stresses during the passage of vehicles on the surface of a geocontainer remain within the strength limits of the container shell material.

Large displacement analysis of egg-shaped containment shells using Lagrange multipliers

In this paper, a large displacement analysis of three-center-combined spherical shells, used as egg-shaped containment structures, is performed using the first and second fundamental forms of the shell surface with two different radii of curvature. The energy functional of the three-center-combined spherical shells system is derived using a variational formulation, and is written in the appropriate form to reduce the computation time in an iterative procedure. The numerical results in terms of displacement, membrane stress, and bending moment resultants are obtained by nonlinear finite element analysis with a fifth-order polynomial shape function. At the spherical shell edge, the Lagrange multipliers technique is used to enforce the discontinuity effect. The main conclusions are that the displacement responses, membrane stress, and bending moment resultants depend on the geometric parameters of the three-center-combined spherical shells. The Lagrange multipliers correspond to the internal forces due to the displacement and the slope at the shell edge in order to sustain the smooth curve for deformed configuration of the three-center-combined spherical shells under uniform pressure. The volume capacity of the three-center-combined spherical shells are more than the spherical shells with a constant radius. Finally, the results indicate that the linear assumption is good enough for all practical purposes. However, the large displacement analysis becomes significant on the tangential displacement, meridional, and circumferential moments under the large value of uniform pressure.

Selection of the configuration of the cross-section of a multi-flue stacks with four inner flues of different diameters

Despite the widespread use of single-flue stacks, due to the possibility of increasing the rise of flue gases into the atmosphere due to the close location of individual flues in a common shell and ensuring the high reliability of this shell by isolating it from flue gases, multi-flue stacks are increasingly being used. To minimize their cost, it is necessary to determine such an arrangement of flues, in which the diameter of the stack shell will be minimal.THE PURPOSE. Consider the main types of multi-flue stacks used in world practice. Obtain an analytical solution for determining the minimum possible diameter of the reinforced concrete shell of a four-flue stack with flues of different diameter.METHODS. Graphical and analytical methods using computer modeling, as well as the use of computer-aided design systems.RESULTS. An analytical solution is obtained to determine the minimum possible diameter of the reinforced concrete shell of a four-flue stack with stems of different diameters at given distances between the flues and between the flues and the containment shell as a solution to a system of algebraic and trigonometric equations. The distances between the flues and between the flues and the containment can be set to any. In this paper, a new methodology and calculation program for four-flue stacks has been developed. It is shown that the shell diameter depends on the arrangement of flues of different diameters. In the absence of space restrictions for flues, flues with the largest diameters should be placed opposite each other. The obtained method for determining the shell diameter due to more accurate design and when all specified conditions are met, allows to reduce the cost of the shell by 4–9 % compared to the current method for determining the shell diameter.

Optimization design of heat dissipation scheme for submarine data center based on analytic hierarchy process

Aiming at the problem of heat dissipation optimization design of submarine data center, firstly, the placement mode of server is designed, and on this basis, the heat generation power of server is analyzed by Newton cooling method of convective heat transfer to determine its feasibility. Secondly, based on the relationship between fluid velocity and pressure and the relationship between fluid velocity and heat dissipation through the container surface, the container structure design and its placement direction are clarified. Then, the optimal container shell material is determined by using multi-attribute decision-making model and analytic hierarchy process. Finally, the quadratic composite function of shell cost and seawater depth with respect to shell thickness is constructed to calculate the appropriate seawater depth. According to the research, considering the structure, placement method, heat dissipation effect and seawater temperature of the container, on the basis that a single container shell can be placed with up to 609 servers, Maraging 300 Steel is selected as the most suitable container shell material.

INVESTIGATION INTO MAGNETIC DRIVE SEALLESS PUMP FAILURE 3 FLARE GAS RECOVERY UNIT (FGRU)

Failure investigation was conducted on magnetic drive centrifugal sealless pumps that had only been operating for six months and were already struggling to rotate. It was discovered that hydrocarbon sludge and other debris had blocked the lubricating channel, which is meant to provide pathways for cooling and lubricating the pump's inner magnetic and containment shell. Further investigation revealed that service water had contaminated the process fluid, precipitating calcium carbonate upon contact with the amine solution and clogging the flushing line. An additional duplex strainer was installed on the repaired pumps, and adequate precautions were taken to prevent water contamination.Keywords: cleanliness, internal flushing, contamination, clogging, duplex strainer

Internal Flow Field and Loss Analysis of a Magnetic Drive Pump’s Cooling Circuit

The cooling circuit is an important component of the magnetic drive pump because it prevents demagnetization of the permanent magnet and damage to the containment shell owing to a high temperature increase. In this paper, the flow field and losses of the cooling circuit of the magnetic pump are discussed and experimentally verified based on numerical simulation methods. Five different lengths of magnetic couplings were designed, and the flow field distribution, cooling flow rate, and loss variation laws of the cooling circuit were analyzed. The results show that the pump flow rate and magnetic coupling length have a minimal effect on the velocity distribution in the cooling circuit. When the magnet length increases from 30 mm to 55 mm, the temperature rise of the cooling circuit and the pressure drop at the gap increase by 23.1% and 25.3%, respectively. When the length of the magnetic coupling remains constant, the cooling flow rate of the cooling circuit falls with an increasing pump flow rate, and it reduces by 8.4% when the pump flow rate increases from 0.7 Q to 1.3 Q. The water friction loss and eddy current loss of the cooling circuit increase with an increase in the magnetic coupling length, while the cooling flow rate decreases. When the magnet length increases from 30 mm to 55 mm, the eddy current losses in the coupling circuit and the water friction losses in the cooling circuit increase by 45% and 35%, respectively, while the cooling flow rate decreases by 13%.

Energy-efficient ceramics

How using ceramic containment shells in magnetic drive pumps could improve energy efficiency and save costs.

Analysis on the results of CAP1400 passive containment cooling system during LOCA scenario via integral test

As an important means of removing decay heat from containment, whether the existing water film coverage design could meet integrity requirements needs to be determined. An integral experiment is carried out to validate this by adjusting the cooling water flow and film coverage associated with the DEGB LOCA scenario. The results show that the current design could ensure the residual heat removal, inhibit the temperature and pressure rise in the containment, even the cooling water flow and film coverage as low as 50% of design values. The energy balance analysis shows that the energy in the current test is derived from the “condensation-conduction-evaporation” path at the containment shell, which undertakes 1/3–2/3 energy removal in the initial stage and almost all rest energy removal in the long-term stage. That is, the condensation and evaporation heat transfer process on the shell is the dominant factor affecting the long-term cooling of the containment incorporated steel internal containment and its passive cooling system via external surface.

Improving the crack resistance of inclined cross-sections of reinforced concrete containment shells in areas of emergency loads of pushing

The object of this research was the crack resistance of inclined sections of concrete and reinforced concrete fragments of protective structures under the action of emergency dynamic loads. The characteristics of dangerous emergency dynamic loads on protective structures (seismic, aircraft attack), the experience of increasing the crack resistance of inclined sections with various materials and design measures under static effects have been described. Areas of influence of dynamic loads on reinforced concrete structures reinforced with horizontal grids near the upper and lower faces need to increase crack resistance and eliminate the risk of splitting in the mesh plane. Comparison of the results of experimental studies of inclined sections of protective structures in the area of influence of local emergency load showed the feasibility of such structural measures. Additional horizontal reinforcement near the pushing face increases crack resistance by 55–65 %. When using the developed theoretical dependences, the error in determining the cracking forces and pushing strength does not exceed 20.7 %. Increased crack resistance is ensured by limiting the maximum diameters of the rods of horizontal grids and their pitch. Especially important is the arrangement of additional reinforcement in the middle zone, taking into account the actual tensile strength of concrete in the calculated dependences. Complete elimination of the danger of splitting in areas of probable action of emergency dynamic load in protective structures in the planes of the grids is recommended through the use of concrete of class not lower than C16/20, the use of reinforcement Ø12–14 mm. The optimal pitch of the rods is 50–125 mm. This makes it possible to increase the reliability of the design and operation of protective structures in case of emergency impacts, to reduce the cost of their repair after such impacts.

Seismic performance upgrading of containment structures using a negative-stiffness amplification system

As an efficient and crucial energy-generation facility, a nuclear power plant requires a high level of seismic safety as its failure can lead to catastrophic events. In this study, a novel negative-stiffness amplification system-strengthened isolation system (NSAS-IS) is constructed for seismic performance upgrading of containment structures. Moreover, a multiperformance-oriented design principle is developed for the NSAS-IS to enable enhanced energy dissipation and robust control during multi-intensity seismic excitations. The NSAS-IS comprises an NSAS and parallelly arranged isolators; in particular, the NSAS comprises a tuning spring in series with a sub-configuration including a negative-stiffness device and dashpot in parallel. Herein, the mechanical models and physical realization of the NSAS and isolators are established, based on which the equivalent negative-stiffness effect and enhanced energy dissipation capacity are elucidated. A mechanical model of an NSAS-IS-equipped containment structure, as the last safety defense of the inner structure of a nuclear power plant, and its governing equation and finite element model are established. A design principle, aimed at multiperformance upgrading, is developed for the NSAS-IS. Considering the typical containment structure as an example, the advantages of the proposed NSAS-IS and design principle are investigated for multiple seismic performances, including the deformation and shear force responses of the isolation layer as well as the deformation and acceleration responses of the containment shell. The results obtained indicate that installing the NSAS-IS at the bottom of the containment structure provides improved isolation owing to the equivalent negative-stiffness effect; consequently, the multiple responses of the superstructure and isolation layer are reduced more significantly than with conventional isolators. Benefiting from the multiperformance-oriented design and deployed NSAS, the new isolation system exhibits an enhanced energy dissipation efficiency and capacity, simultaneously maintaining the isolation phenomenon. Thus, the total energy dissipation burden on the primary structures can be relieved by the NSAS, which robustly dissipates intense vibrational energies during multi-intensity excitations.

DEVELOPMENT OF MODELS OF POLYHEDRON CONTAINERS FOR DELIVERY OF FIRE-EXTINGUISHING SUBSTANCES

Geometric models of containers for the delivery of extinguishing agents to a fire zone located at a considerable distance are proposed. The transportation technology is based on a mechanical throwing operation. For this, a substance (for example, a fire extinguishing powder) is placed in a hard shell - a special container. After delivery to the fire site, the container must collapse and release a substance that will assist in extinguishing the fire. The existing method of remote delivery uses a container that is in the shape of a cylinder. In this case, a pneumatic gun is used as a launch pad. The difficulty lies in the fact that in order to ensure stability of motion during the flight, the cylinder must rotate around its axis. The starting impulse to such rotation when the barrel passes through the muzzle of the air gun is provided by compressed air flows that are difficult to commute.
 Therefore, it becomes necessary to develop new methods for the remote delivery of fire extinguishing agents to the fire zone by applying other principles of throwing. Among such methods, attention is drawn to the use of trebuchet mechanisms and impulse installations. In the case of using trebuchet mechanisms for containers, shapes close to spherical are chosen. For impulse installations (with squibs), it is advisable to use containers consisting of two spherical containers connected by a rod (like a sports dumbbell). In this case, the initiation of the rotational-translational movement of the dumbbell in the vertical plane is carried out due to the action of explosive impulses directed at each of its loads in a pre-calculated manner.
 For practical application of trebuchet mechanisms or impulse installations, it is necessary to develop container shell designs. To do this, you need to combine solutions to several problems with conflicting requirements. First, the construction of the dumbbell must be strong and withstand the starting forces and stresses of the flight phase. Secondly, the structure must ensure its instant destruction after delivery to the fire zone. And, thirdly, the design of the dumbbell should provide a convenient technology for filling containers with fire extinguishing agents. It is proposed to solve this problem using polyhedral bodies.

SOME RESULTS OF SOLVING THE NON-STATIONARY PROBLEM OF GAS DIFFUSION IN POLYETHYLENE

The problems of diffusion of molecular oxygen and ethylene in amorphous-crystalline polyethylene are considered. The temperature of the medium is assumed to be constant, and the diffusion process is described by the classical Fick partial differential equations. It is assumed that the material obtained from the polyethylene granules using the thermomechanical extrusion process is located in a limited sealed container. The impermeability of the container shell leads to the need to take into account the parameters of the gas in the free volume. The problem is nonlinear and non-stationary, and it is assumed that the rate of interphase processes at the gas-polyethylene interface significantly exceeds the rate of diffusion. Using the finite element method, numerical results are obtained describing the process of oxygen evacuation from polyethylene and the process of ethylene diffusion into the material, at different values of the external pressure of the penetrant gas. The main characteristics of these processes are determined. An effective variant of double vacuuming is considered, which makes it possible to obtain a significantly lower concentration of oxygen in polyethylene. The results are of practical significance for evaluating the parameters of the production of high-quality heat-shrinkable polyethylene pipes produced by the technology of gamma-ray radiation exposure in the protective environment of an inert gas.

Design of one-dimensional heat conduction model for thin-walled fin in submarine data center

In recent years, due to the rapid growth of big data center in coastal cities, and the high cost of land construction, occupying more land, cooling consumes a lot of power and cold water resources, causing a prominent resource contradiction, thus the undersea data center came into being. Undersea data center project does not occupy or rarely occupies land resources, saves energy consumption, does not need fresh water consumption, and can greatly shorten the distance between data and users, and has the characteristics of low cost, low delay, high reliability and high security, so as to realize the green and sustainable development of big data center. However, the is a new project, there are still many areas to be improved. How to design the container shell structure for heat dissipation is a very worthy of discussion. Firstly, we determine the geometry of the container by comparing the surface area of the cuboid and the cylinder under the same volume; Then, in order to ensure more sufficient heat dissipation conditions, we consider increasing the surface area of heat dissipation by adding fins. A one-dimensional heat conduction model of thin-walled fin is established. Under different thermal conductivity conditions, rectangular fin, triangular fin or parabolic fin are arranged. Finally, we designed the overall shape of the container and select the material of the shell to ensure the best heat dissipation effect.

Water electrolyzer for renewable energy systems

The article is devoted to the features of the alkaline water electrolyzers use in power plants with a hydrogen energy storage systems based on renewable energy sources. The technology of nickel–cobalt electrodes electrochemical formation according to a printed 2–dimensional sketch is proposed. A new technique for the synthesis of diaphragms with a zirconium hydroxide hydrogel as a hydrophilic filler is considered. The current–voltage characteristics of an electrolytic cell located inside outer containment shell, designed for pressures up to 160 atm, are investigated.

The mechanism of liquid dispersing from a cylinder driven by central dynamic shock loading

A systematic investigation on the mechanism of dynamic liquid dispersing process via theoretical and experimental approach is presented. The experiments include weak and strong constrained scenarios using the high-speed camera technique and the flash X-ray radiography technique. Based on dynamic analysis, one-dimensional characteristics analysis and some numerical simulations on the propagating processes of blast waves before the container shell rupturing, further and detailed analyses of the experimental results are presented. The effects of the liquid viscosity on the dynamic dispersing flow are also analyzed, and the spall fracture mechanism is explored. Thus, the dominating forces determining the dispersing liquid flow are revealed, that is, the stretching and shearing action due to the interaction of two reflecting rarefaction waves in opposite propagating directions. The influence of container shell strength on the dispersing liquid flow is also investigated, and the characters of cavitation layered in liquid before shell rupturing are uncovered. Results revealed that different shell material results in different cavitating layers. Then the different cavitating layers drive the different dynamic liquid dispersing process coming into being. The metastable liquid states caused by pressure drop and cavitation generation are discussed.

The Container Image Schema as the Conceptual Basis of English Adjectives’ Semantics

This paper focuses on the cognitive foundation of the semantics of English adjectives that denote mental and moral characteristics of human beings. Research into these adjectives seems a challenging task because they denote abstract qualities that cannot be perceived through vision, hearing, or touch; and here a question arises: How are abstract qualities interpreted in English encoded through adjectives? To answer it, this study follows the idea of two-level semantics, i.e. word semantics is treated as a two-level phenomenon that comprises the semantic (external) level and the conceptual (deep) one. This study is the first to address adjectival semantics from this perspective. Here a novel approach to revealing the cognitive foundation of adjectives is introduced: given that adjectives originated from old syncretic items and a word cognitive model forms at the moment of word creation, cognitive models underlying adjectives' semantics are unearthed via analysis of their etymological data. Our contribution is two-fold. First, the approach has revealed that the image schema CONTAINER guides semantics of an array of various adjectives independent of their morphemic structure or date of origin. The examples demonstrate that abstract human qualities are interpreted via the following container features: boundary, container substance, size, hardness/softness of a container shell, etc. The semantics of affixed or compound adjectives appear to stem from the integration of concepts represented by an affix and a root or two roots, respectively. Second, the findings show that the value given to every container feature appears to predetermine the evaluation conveyed by an adjective. Container features tend to possess ambivalent value, realizing the positive or negative one due to the interaction with a frame in which the CONTAINER is incorporated, therefore the same polysemantic adjective may develop both positive and negative meanings. To reveal the whole inventory of cognitive models that govern adjectival semantics in English, further research needs to be conducted.

Detection System for U-Shaped Bellows Convolution Pitches Based on a Laser Line Scanner.

An expansion joint is mainly composed of bellows and other components; it is attached on a container shell or pipe to compensate for the additional stress caused by temperature differences and mechanical vibrations. In China, the expansion joint fatigue tests are often used to assess the quality of products. After fatigue tests, convolution pitch will be changed. The amount of change is an important index that can be used to evaluate bellows expansion joints. However, the convolution pitch detection is mainly done manually and randomly by inspection agencies before shipping to the end users. This common practice is not efficient and is often subjective. This paper introduced a novel method for automatically detecting the change of the convolution pitch based on a laser line scanner and data processing technology. The laser line scanner is combined with a precision motorized stage to obtain the point cloud data of the bellows. After denoising and fitting, a peak-finding algorithm is applied to search for the crest of a convolution. The method to find the convolution pitch and the decision that needs to be made to ensure product eligibility are described in detail. A DN500 expansion joint is used as a sample to illustrate the efficiency of the system. The application of the technique intuitively allows a higher precision and relative efficiency in quality inspection of bellows expansion joints. It has also been implemented in the Special Equipment Safety Supervision and Inspection Institute of Jiangsu province with great success.

Monitoring of Nuclear Power Plant Containments During the Acceptance Tests

The article presents the results of the study of changes in the stress-strain state and the geometric parameters of the containment shell near the junction of the cylindrical part with the dome and in the area of the crane rail of the polar crane during the acceptance tests.

Experimental study on flame spread along fuel cylinders in high pressures

SummaryFlame spread over solid fuels in high‐pressure situations, such as nuclear containment shells during a pressurized period, has potential to result in catastrophic disaster, thus requiring further knowledge. This paper experimentally reveals the flame spread behaviors over fuel cylinders in high pressures. Polyethylene and polymethyl‐methacrylate cylinders with the diameter of 4.0 mm are used in this study. Ambient gas is air, and total pressures are varied from naturally normal pressure (100 kPa) to elevated pressure (500 kPa). Flame characteristics including flame appearance and flame size and burning rate and flame spread rate are investigated. Results show that in high pressure, the flame appearance is significantly affected. As the pressure increases, the blue flame disappeared, and the color of flame tip changes from luminous yellow to orange as well the orange part extends down towards the base of flame. The dimensionless flame height increases with pressure for pressure below 150 kPa and then decreases with pressure above that level. The burning rates show increasing trend with pressure and are proportional to P0.6 and P0.79 for polymethyl‐methacrylate and polyethylene, respectively. Besides, flame spread rates for polymethyl‐methacrylate and polyethylene both were found to be proportional to P0.5.