Pressure Vessel Research Articles

Performance analysis of a novel isothermal compressed carbon dioxide energy storage system integrated with solar thermal storage

The significant increase in renewable energy generation will lead to the unstable operation of the power system. Compressed carbon dioxide energy storage (CCES) is a promising energy storage technology, which can smooth the output of renewable energy. However, one of the disadvantages of conventional CCES is the need to store compression heat, which leads to the complex structure of heat storage units. In this paper, an isothermal CCES system integrated with solar thermal storage is proposed and modeled. The parameter variations of work fluids in the pressure vessels with time and the thermodynamic properties and economics of the system are analyzed. The results show that the round-trip efficiency is 107.14 %, the energy storage density is 5.174 MJ/m3, and the levelized cost of electricity is 0.142 $/kWh. The component with the highest exergy destruction is the regenerator, followed by the LP units. The combination of liquid spray technology can decrease the highest temperature of carbon dioxide in the pressure vessel from 358.80 K to 309.39 K and increase the isothermal compression efficiency from 78.72 % to 92.26 %. Increasing the liquid spray flow rate and decreasing the hydraulic pump flow rate can both make the actual compression process closer to the isothermal process.

Improved marine predators algorithm for engineering design optimization problems

The Marine Predator Algorithm (MPA) has unique advantages as an important branch of population-based algorithms. However, it emerges more disadvantages gradually, such as traps to local optima, insufficient diversity, and premature convergence, when dealing with complex problems in practical industrial engineering design applications. In response to these limitations, this paper proposes a novel Improved Marine Predator Algorithm (IMPA). By introducing an adaptive weight adjustment strategy and a dynamic social learning mechanism, this study significantly improves the encounter frequency and efficiency between predators and preys in marine ecosystems. The performance of the IMPA was evaluated through benchmark functions, CEC2021 suite problems, and engineering design problems, including welded beam design, tension/compression spring design, pressure vessel design, and three-bar design. The results indicate that the IMPA has achieved significant success in the optimization process over other methods, exhibiting excellent performance in both solving optimal parameter solutions and optimizing objective function values. The IMPA performs well in terms of accuracy and robustness, which also proves its efficiency in successfully solving complex industrial engineering design problems.

Exact solutions for the elastic-plastic response of functionally graded pipe under external pressure

This study investigates the influence of material gradient on the elastoplastic response of functionally graded (FG) thick-walled pipes subjected to external pressure. Closed-form solutions are derived for radial and circumferential stresses across various stages: purely elastic, partially plastic, and post-unloading from plastic regimes. Both the elastic modulus and yield stress exhibit radial variation defined by power-law functions, while Poisson's ratio remains constant. The stress distribution within the pipe depends not only on the external pressure but also on the material gradient index and the geometric dimensions of the pipe. A method is presented to accurately determine the first yielding position in a thin-walled tube based on the material gradient index by employing Tresca's yield criterion. Plastic zones nucleate at one or both surfaces as external pressure increases. The propagation of elastoplastic interfaces and stress distributions within each zone are examined in detail. Notably, following plastic deformation and complete unloading, FG thick-walled pipes may exhibit re-emergence of plastic deformation, depending on the pre-unloading stress state and the gradient of the elastic modulus. The conclusions of this work expected to aid in the design of FG pressure vessels and improve their load-carrying capacity and safety.

Research progress on thermal aging of reactor pressure vessel steel

Nuclear energy is highly valued in many countries for its reliability, cleanliness and cost-effectiveness. Ensuring the safe development and utilization of nuclear energy has become crucial for addressing the global energy shortage and mitigating climate change. The reactor pressure vessel (RPV) is exposed to a high-temperature, high-corrosion and high-radiation environment, the RPV materials have a significant impact on the stability and safety of a nuclear power station. In this paper, the effects of long-term high-temperature hot aging on microstructure and mechanical properties of RPV steel, as well as the research progress in embrittlement mechanism and service life prediction, are reviewed. At the same time, the existing problems and further research directions of RPV steel are pointed out.

Effect of fiber orientation and reinforcements on the performance of composite pressure vessel using finite element analysis

Effect of fiber orientation and reinforcements on the performance of composite pressure vessel using finite element analysis

Development of a Novel Pressure Vessel System for the Simulation of Starch Expansion – Methylated and Regular Waxy Corn Starch Behave Significantly Different With and Without Cellulose Inclusion

AbstractFortification of direct‐expanded products with insoluble fiber generally leads to decreased expansion. Understanding the interactions between starches and fibers can help to include more fiber into puffed products. A pressure vessel setup is developed to allow for a small‐scale expansion process. Because trends for the expansion ability during the simulated process are similar to those during extrusion, the setup has been proven to be suitable for understanding the occurrences during extrusion. Elimination of hydroxyl groups through starch methylation can help to understand the role of hydrogen bonding during expansion. Nonmethylated and methylated starch are tested for their expansion at cellulose levels of 0%, 5%, and 20% on a weight basis. The specific volume of the obtained samples is used to determine the degree of expansion. The nonmethylated starch sample exhibits a specific volume of 16.3 ± 1.8 cm3 g−1, which is almost three times higher than the one of the methylated sample (≈6.0 cm3 g−1). Possible reasons for this decrease are the elimination of hydroxyl groups capable of forming hydrogen bonds or the significantly higher viscosity of the methylated starch. While fortification with 5% cellulose does not affect the expansion, 20% cellulose greatly reduces the specific volume for both starches.

Crack propagation characteristics and fatigue life of the large austenitic stainless steel hydrogen storage pressure vessel

Hydrogen-induced cracking or embrittlement can have a substantial and severe impact on the fatigue life of large austenitic stainless steel hydrogen storage pressure vessels. In this study, a dynamic model for the plastic zone in the crack tip considering the hydrogen diffusion was established and a correction factor for the stress intensity factor of the hydrogen storage pressure vessel was proposed for 316L stainless steel, which is commonly used pressure vessel material. The crack propagation characteristics and fatigue life of the stainless steel vessel were investigated. The results indicated that the shortest fatigue life under hydrogen pressure occurs at the intersection of the vent nozzle and the vessel head. The hydrogen environment not only reduces vessel service life but also makes the influence of pressure on cracks propagation more pronounced. It leads to a significant reduction in the fatigue life of pressure vessels when overpressure happens during operation. These research findings are valuable for the accurate assessment of the vessel fatigue life and improving the quality of large hydrogen storage vessel structures.

Interaction Assessment of Stress Intensity Factors of Surface Cracks on Thick Cylinders under Tension Force and Bending Moment

From an engineering perspective, hollow cylinders have various applications in the industry due to their strength, versatility, and geometric properties, making them vital for various applications in diverse industries. Therefore, it could be seen in many aspects such as fluid conveyance, manufacturing and fabrication, rotating machinery, structural components, storage, and pressure vessels. As it is well-known fracture is the most dominant type of failure in cylinders that is caused by defects or flaws. With time, these cracks (flaws) may extend and lead to a tragic failure, posing significant risks to both the nearby environment and humans. Moreover, crack cooperation which is known as (crack interaction) represents a chief apprehension, where cooperation or interaction may accelerate the crack growth and cause unpredictable failure. In this work, a wide variety of crack configurations were examined to quantify the interaction of double-interacting surface cracks located on a thick cylinder numerically via ANSYS software. The Stress Intensity Factor (SIFs) has been utilized as a driving force to describe the crack interaction. The results found that crack interaction influenced both cracks by the same rate, and SIFs distributed along the crack front by the same style as that of a single crack. Also, an inversely proportional relationship has been found between the crack interaction and the separation distance between the cracks. It is possible to conclude that the crack interaction of double interacting cracks exhibited a shielding effect, where SIFs for the case of double cracks were less than those of single crack.

Efficient Design Methods for Variable-Angle-Tow Composite Toroidal Pressure Vessels

Pressure vessels are widely used in various aerospace and automotive applications. For some applications with limited space, spherical and ellipsoidal shapes are less attractive than toroids. Toroidal shapes can be defined as curved, endless hollow shapes that eliminate the need for end caps when used for pressure vessels. This study presents an analytical formulation using lamination parameters for the novel design of toroidal pressure vessels. The proposed design is based on stiffness tailoring by changing the fiber tow trajectories spatially through the structure to suppress the direct stress and strain gradients in the thickness direction, leading to reduced structural weight, defined as bend-free variable-angle-tow (VAT) toroidal pressure vessels. For a toroidal pressure vessel with a fixed geometry, the VAT distribution through the structure to suppress bending is obtained. Subsequently, the bending stresses and strain levels in the designed VAT toroidal pressure vessels are assessed numerically and compared with those of their isotropic and constant-stiffness composite counterparts. Results show that the designed VAT toroidal pressure vessel generates considerably lower degrees of bending than its corresponding isotropic and constant-stiffness composite counterparts.

Design and research on ultra-high pressure sealing structure based on tight plug ring

A new ultra-high pressure sealing structure was designed based on the sealing requirements of ultra-high pressure vessels, using a tight plug ring. The finite element method was used for simulation analysis. The results show that the contact pressure on the sealing surface of the tight plug ring is linear with the vessel pressure, which is always greater than the vessel pressure. To further verify its sealing performance, a semi-closed bomb test device was designed based on the principle of the semi-closed bomb, which can generate a pressure of 300 MPa. The test pressure exceeded 300 MPa multiple times, but no gas leakage was observed. The comprehensive research results indicate that the sealing structure has good performance and can meet the sealing requirements of 300 MPa ultra-high pressure.

Power feasibility of single-staged full-scale PRO systems with hypersaline draw solutions

Pressure retarded osmosis (PRO) is a process that allow to generate energy from osmotic gradient. This process uses selective membranes in order to produce electrical energy through a hydraulic turbine. PRO can be used as a renewable energy technology where water resources are inexhaustible. PRO has the advantage of knowing when and how much energy will be produced. Unfortunately at the moment there are certain limiting factors concerning membrane and module characteristics that have prevented PRO to be fully exploited at full-scale. This study aims to assess the impact of hypersaline draw solutions (60–180 g L−1), membrane characteristics such as structural parameter, module membrane surface and permeability coefficients on the net energy generated by single-staged full-scale PRO system with up to 8 spiral wound membrane modules (SWMMs) in series in a pressure vessel. To carry out this study, characteristics of existing PRO membranes at lab-scale were scaled up to 8 inches SWMM. The results showed the change in the optimal operating parameters with the change of membrane characteristics and draw solution concentration. This study concluded that single-staged full-scale PRO process would be viable from an energy point of view if membranes were manufactured on an industrial scale and with the characteristics of existing membranes on a laboratory scale.

A new analytical tool for the elastic/plastic buckling design of pressure vessels subjected to external pressure

This paper deals with the elastic/plastic buckling design of pressure vessels under external pressure loading. The objective is to build a simple analytical tool devoted to the elastic and elastoplastic buckling analysis of pressure equipments. This tool is aimed to provide the critical external pressure of cylindrical pressure vessels with ellipsoidal (or possibly hemispherical) heads. Depending on the geometry of the equipment and material parameters, the first buckling pressure may involve either the cylindrical shell or the closure ends, in the elastic or plastic range. The calculation tool will be thus based on a series of exact or approximate analytical solutions of the critical pressure of each part of the considered equipment. In this paper, the elementary shell structures involved in such pressure equipments are first individually examined. The fundamental critical pressures for each of them are recalled or introduced, both in elasticity and plasticity. The new solutions are validated against reference numerical results obtained through finite element computations. Then, approximate solutions of the critical pressure are derived for the same shells, taking account of specific boundary conditions (and not idealized ones, as before) due to the presence of the remaining part of the equipment. In the end, a VBA Excel software is developed. It is able to provide the mappings of the buckling mode type and the corresponding critical pressures for large ranges of geometric and material parameters in a very efficient way. These analytical solutions are finally confronted to numerical calculations performed on complete pressure equipments and they are shown to give quite reliable results. A discussion is also initiated on the use of such a program to update the current design rules in this scope of application.

ASME Nondestructive Examination (ANDE) Designated Test Organizations (DTOs)

Control of Nondestructive Examination (NDE) and Quality Control (QC) practical examinations are essential for an ANDE Designated Test Organization (DTO). This presentation describes the infrastructure, security, quality system, and practical demonstration requirements as part of the application to be recognized as an ANDE DTO. A key presentation component is the explanation of sourcing, validation, security, and control of the practical demonstration specimens. Acquisition of the practical demonstration specimens, the examination process steps, and applicant administration are key to the ANDE DTO examination designation. Practical demonstration infrastructure includes the physical location, ANDE material and applicant traffic flow, and the sequence of operations for personal practical demonstrations. Learn more about the details of ANDE Certification Body (CB) preparation to meet the rigorous quality system requirements. An ANDE DTO quality system must meet the quality requirements based on ISO 17024 quality system conformance. Other quality system requirements, dependent on regulatory and statutory criteria such as nuclear pressure vessel codes compared to non-nuclear pressure vessel codes can impact the designation of the DTO. This presentation includes an overview of how the tracking of the applicant, specific NDE/QC methods, test categorization, and the test specimens are organized. Reference to the ASME Nondestructive Examination (ANDE) standard will be included as part of this presentation.

The Dispersion Calculator - a free software for calculating dispersion curves of guided waves

The nondestructive inspection of components by means of guided waves is an emerging technology in fields like aerospace or pipeline construction and maintenance. The guided waves' capability of propagating many meters in a structure is utilized for swift inspection tasks as well as structural health monitoring. The German Aerospace Center uses Lamb waves for the quality assurance of large-scale aerospace vehicle components made from carbon composites. However, the use of guided waves in NDT requires knowledge of the dispersion curves. DISPERSE is the most renown software for the calculation of dispersion curves. This paper presents the open source Dispersion Calculator (DC). The MATLAB® -based DC is an interactive and fully validated software for the computation of dispersion curves and mode shapes of guided waves in isotropic plates and multilayered anisotropic composites. Damping caused by viscoelasticity and fluid-loading can be considered. DC features the capability of calculating laminates consisting of several hundreds of layers so that even the largest specimens, like rocket booster pressure vessels, can be calculated. This is made possible through the implementation of the stiffness matrix method. DC is also able to distinguish the different mode families, like symmetric, antisymmetric, and nonsymmetric Lamb, shear horizontal, and Scholte waves, depending on the symmetry and coupling properties of a given layup. Lastly, DC features a highly efficient and robust dispersion curve tracing algorithm. DC is available at GitHub, and it has gained many users world-wide since its initial release in 2018.

Simulation Study on Defect Damage Behavior of Fe under Irradiation Environment

Abstract As a commonly used structural material in nuclear power plants, Reactor pressure vessel (RPV) steel is subjected to high-energy neutron irradiation from the reactor core for a long time, and the service environment is harsh. The accumulation of point defects (interstitial atoms and vacancies) generated by irradiation over a long period can seriously affect the microstructure of the material. The macroscopic properties of the material changed until the material failed, which threatened the safety and operation stability of nuclear power plants. This paper used the method of molecular dynamics to simulate the cascade collision process of Fe in the irradiation environment. The relationship between different factors and radiation damage defects was studied. Firstly, the quantity of the Frenkel pairs increases rapidly in the irradiation environment, and then recombination occurs after reaching the peak, which makes the quantity of the Frenkel pairs decrease rapidly. Finally, the quantity of Frenkel pairs is in a stable trend. When PKA energy and temperature increase, the higher the quantity of Frenkel pairs at the peak is, the higher the recombination rate of defects is. Meanwhile, the larger the cluster size of interstitial atoms and vacancies is, the greater the corresponding quantity of clusters is. As PKA energy increases, the quantity of residual Frenkel pairs at stability increases, while the number of residual Frenkel pairs at stability decreases with temperature. This is attributed to the intense thermal motion of molecules at high temperatures, resulting in the quantity of Frenkel pairs decreasing at the stable stage. Therefore, by simulating the irradiation damage process of Fe, the prediction of material irradiation damage under a neutron irradiation environment is provided, and the service life of materials can be provided with theoretical guidance.

Modeling, fabrication, and burst testing of type-IV 3D printed plastic liner composite overwrapped pressure vessels

Modeling, fabrication, and burst testing of type-IV 3D printed plastic liner composite overwrapped pressure vessels

Mathematical modeling of reverse osmosis system design and performance

ABSTRACT Reverse osmosis (RO) is one of the most effective technologies for water desalination. However, the RO system's performance is contingent on its design parameters and operating conditions. In this study, a computational model for RO desalination performance prediction was developed. The study compares the performance parameters of the RO system utilizing various types of membranes with the established model using a single pressure vessel and seven membrane elements within the pressure vessel. This study looked at two different feed water concentrations. The first is for saltwater with a concentration of 40,000 mg/L, while the second is for seawater with a concentration of 32,000 mg/L. WAVE software assessed the findings of the generated model to the recovery ratio, feed pressure, salt rejection, and permeate concentration of each membrane element inside the pressure vessel. The results of the study show good similarity between the simulation model results and the results obtained by WAVE software as they are illustrated in Figures 4–7.

Performance Assessment of Natural Survivor Method-Based Metaheuristic Optimizers in Global Optimization and Engineering Design Problems

This study presents the comparative performance analysis of Natural Survivor Method (NSM)-based algorithms in solving the IEEE CEC 2022 test suite benchmark problems and four real-world engineering design problems. Three different variants (Case1, Case2, Case3) of the NSM-TLABC, NSM-SFS and NSM-LSHADE-SPACMA algorithms were used in the study. The data obtained from the experimental studies were statistically analyzed using Friedman and Wilcoxon signed-rank tests. Based on the Friedman test results, NSM-LSHADE-SPACMA_Case2 showed the best performance with an average Friedman score of 3.96. The Wilcoxon signed-rank test showed that NSM-LSHADE-SPACMA_Case2 outperformed its competitors in 13 out of 16 experiments, achieving a success rate of 81.25%. NSM-LSHADE-SPACMA_Case2, which was found to be the most powerful of the NSM-based algorithms, is used to solve cantilever beam design, tension/compression spring design, pressure vessel design and gear train design problems. The optimization results are also compared with eight state-of-the-art metaheuristics, including Rime Optimization Algorithm (RIME), Nonlinear Marine Predator Algorithm (NMPA), Northern Goshawk Optimization (NGO), Kepler Optimization Algorithm (KOA), Honey Badger Algorithm (HBA), Artificial Gorilla Troops Optimizer (GTO), Exponential Distribution Optimization (EDO) and Hunger Games Search (HGS). Given that all results are together, it is seen that NSM-LSHADE-SPACMA_Case2 algorithm consistently produced the best results for the global and engineering design problems studied.

Deuterium retention in co-deposition with lithium in Magnum-PSI: experimental analysis and comparison with SOLPS-ITER

The vapor-box, a liquid metal design for the divertor, utilizes lithium recirculation through evaporation and condensation. Safety concerns arise from Li-D/T formation and co-deposition on vapor-box walls and the first wall, affecting tritium retention. Additively manufactured tungsten capillary porous structure (CPS) samples with Li were exposed to high heat flux D plasmas in the linear plasma device Magnum-PSI, to study D retention in Li–D co-deposition dependence on substrate temperature (200 ∘ C–428 ∘ C) and distance from the plasma beam center (25–85 mm). The D:Li ratio was determined via in-situ ion beam diagnostics with simultaneously analyzed Nuclear Reaction Analysis and Elastic Backscattering Spectroscopy spectra to maximize the precision. Experimental results approach close to the theoretical maximum at 40:60 D:Li ratio and deposited film thickness ranging from 0.02 to 3.2 µm. Witness plate temperatures above 400 ∘ C yielded Li films under 150 nm in thickness with lower D:Li ratios (5:95 D:Li ratio). At this temperature LiD decomposition pressure is comparable with vessel pressure during plasma. SOLPS-ITER simulations narrowed CPS surface temperature to 650 ∘ C–700 ∘ C, indicating Li+ plasma dominance near the target surface. Redeposition ratio of lithium on the CPS surface was determined to be around 80 % , matching quartz crystal microbalance results. However, SOLPS-ITER simulations lacked accuracy in recreating observed Li and D deposition layers on WPs, improvements are needed to model plasmas with significant Li quantities. Extension of SOLPS-ITER simulations to include LiD molecules and enhance heat flux accuracy is crucial for better alignment with experimental data.

Probabilistic fracture mechanics analyses of a reactor pressure vessel using the irradiation embrittlement evaluation based on the Bayesian nonparametric method

In the structural integrity assessment of an embrittled reactor pressure vessel (RPV) based on probabilistic fracture mechanics (PFM), it is crucial to consider both of the mean value and the uncertainty of the embrittlement prediction. Typically, the embrittlement prediction uncertainty is given by a normal distribution, and its standard deviation is determined from the residuals of the measured and predicted values of all data used to develop the embrittlement prediction method. Therefore, the same uncertainty is assumed regardless of neutron fluence and the available data. To overcome this issue, the Japan Atomic Energy Agency recently developed the embrittlement prediction method based on machine learning and Bayesian statistics, i.e., the Bayesian nonparametric (BNP) method, and introduced it to the PFM analysis code. The BNP method can predict the probability distribution according to data scarcity and provide more reasonable uncertainty because it estimates significant uncertainties where the scatter of actual measured data is large and the number of data is small. In this study, PFM analysis for a Japanese model RPV in a pressurized water reactor is conducted using the PFM analysis of structural components in aging light water reactors, where the embrittlement probability distribution calculated using the BNP method is used. Furthermore, the effects of different embrittlement prediction methods and uncertainties on the failure frequency of RPVs are investigated in the PFM analyses, and the results are presented.