Tank Design Research Articles

PCM-Filled Capsules (RT44HC) for Heat Storage—Laboratory Scale Pilot Study

Peak power shaving in heating systems can be achieved using heat accumulators, traditionally implemented in the form of water storage tanks. Their heat capacity can be increased by using a phase change material (PCM) instead of water, which, however, usually requires a change in the tank design. The innovation of this paper is an interesting concept to use plastic capsules filled with a PCM that replace part of the water volume in an existing heat accumulator. The aim of this paper is to compare the cooling rate of the same volume of water as that of the water mixed with the PCM capsules to initially verify the heat storage potential of the capsules. The results of pilot experimental studies on a laboratory scale are presented and discussed, showing the potential of this idea for heat storage. The partial replacement of water with capsules (40% of the total volume) results in significantly faster heat accumulation with the same tank volume (3.85 times at the beginning of the process) and more heat stored (decrease in the temperature of water alone by 14 K and water with PCM capsules by 26 K in the same period of time), which gives promising perspectives for the use of this solution on a semitechnical scale and further in a real-size heating system.

Numerical simulation of oil-water separation in sedimentation tank based on CFD-PBM model

ABSTRACT A significant amount of wastewater has been produced from the oilfield extractive fluid with the development of oilfields in recent decades. Settling is the first process in the treatment of oilfield wastewater. As one of the most crucial devices in oilfield wastewater treatment, the vertical sedimentation tank has been widely utilized in the precipitation process. This work aims to explore the properties of vertical sedimentation tanks for oil-water separation and analyze related variables in the separation. First, we utilize the for-profit software Fluent for computational fluid dynamics, in which the RNG k-ε model, the multiphase flow mixing model, and the PBM model are used to simulate the internal flow field distribution in the vertical sedimentation tank under various boundary conditions. Then, the implication of changing the boundary conditions on the vertical sedimentation tanks is analyzed. It is demonstrated that by replacing the PBM model for the homogeneous particle size, the simulation of oil-water two-phase flow in sedimentation tanks is more correctly measured. The findings demonstrate that raising the operating temperature increases the oil content at the output and dewatering rate of the sedimentation tanks by 73.1%; however, above 44°C, the effect of oil removal gradually tends to deteriorate; the longer hydraulic retention time within the 8-h range, the better the effect of oil-water separation, with the best effect occurring at 8 h; and the more viscous the oil phase, the more resistance of the oil droplets to float, increasing the water phase oil-carrying capacity, resulting in a 36.5% reduction in oil content at the outlet and dewatering rate of the settling tanks. The simulation in this paper can provide theoretical direction and conference for the design of vertical sedimentation tanks, as well as improve the performance of oily wastewater treatment facilities.

Determining the stability of a fire truck tanker against overturning while driving through crossed forest terrain

The object of this study is to consider dynamic processes in the tank of a fire truck with different levels of water filling. The task to be solved is to determine the data on the fluctuation of the center of mass of a dynamic system, which consists of the water tank of a fire truck tanker truck, when it moves through rough forest terrain at different speeds. The data make it possible to predict the danger of a fire truck tipping over. In the process of solving the task, an estimation model of a fire truck tanker truck was built together with a water tank, using the LS-Dyna dynamic systems simulation software package. In order to reproduce the dynamic impact on the fire truck tanker with the water capacity exerted by the relief of the rugged forest area, the time dependences of the angles of current position of the fire truck tanker – roll angle, yaw, and pitch – were established. The resulting dependences were used as boundary conditions to reproduce the dynamic influence of the terrain. The turning angles of the water tank of a fire truck were determined depending on the unevenness of the terrain, the geometry of which was calculated by a pseudo-random number generator. Using the explicit method for integrating the dynamics equations, implemented in the code of the LS-Dyna software package, the patterns of fluctuations of the center of mass of the water tank of the fire truck tanker depending on the level of filling and speed of movement were defined. Using results from the mathematical modeling of dynamic processes in the fire truck tanker, a numerical algorithm was developed for this fire truck tanker to maintain its stability against overturning. Therefore, the results of this study have a direct practical application in the field of fire truck tanker design safety and could be used to improve and devise new technologies in this field

Estimation of the Effect of Oblique Positioned Obstacle Placement on Thermal Performance of a Horizontal Mantle Hot Water Tank with Machine Learning

Due to the growing popularity of vacuum tube solar collectors and their more esthetically pleasing look, horizontal hot water tanks are increasingly being used in solar hot water systems. In order to improve the thermal performance of a horizontal mantled hot water tank, this work numerically examines the impact of positioning inclination barriers parallel or coincident to one another at varying angles. The main input provided the velocity V = 0.036, 0.073, 0.11, and 0.147 m/s, and analysis were performed for each speed. The study concluded that V = 0.073 m/s was the ideal mains input velocity for each scenario and that raising the speed typically resulted in a lower mains outlet temperature. According to the study’s findings, the tank design with the first obstacle 150 mm away and the two obstacles 100 mm apart achieves the best efficiency. The residential water temperature in this model is 312 K, while the storage water temperature is 309.5 K. In this study, a feed-forward artificial neural network (ANN) model based predictor was designed to estimate the mantle outlet and main outlet temperatures and the temperature of the stored water. Analyses were performed for different network inlet velocities and obstacle combinations, and ANN showed superior performance in estimating temperature parameters.

Sloshing analysis of an isothermal fluid in a cylindrical tank for cryogenic tank design using smoothed particle hydrodynamics

Sloshing analysis of an isothermal fluid in a cylindrical tank for cryogenic tank design using smoothed particle hydrodynamics

IMPLEMENTATION OF A DOUBLE-SHELL METAL HYDRIDE TANK INTO REAL BUS OPERATION AND ITS TEST RUNS

Recently, the role of hydrogen technology has become more important in decarbonizing society and achieving carbon neutrality goals. The most important sector where it is possible to implement hydrogen technologies to achieve carbon neutrality is the automotive industry. For hydrogen technologies in the field of transport to be able to compete with conventional motor vehicles, research in several areas is necessary. One of the most important areas is the issue of hydrogen storage. The article in question discusses the issue of low-pressure hydrogen storage by means of metal hydride storage tanks for mobile applications and solves the design of a double-shell metal hydride storage tank using an active and passive cooling module and the subsequent implementation of the metal hydride storage tank in the real operation of a bus on which test runs were carried out and evaluated. From the test runs, it was found that research and development in the field of initial preheating of the metal hydride storage tanks in the bus is necessary for the efficient removal of hydrogen into the fuel cell.

ҚАТТЫ ЦЕНТРІ БАР ДӨҢГЕЛЕК ОСЬТІК СИММЕТРИЯЛЫҚ МЕМБРАНАНЫҢ ФИЗИКАЛЫҚ ЖӘНЕ ГЕОМЕТРИЯЛЫҚ ПАРАМЕТРЛЕРІН ОҢТАЙЛАНДЫРУ

The mathematical model of an isotropic circular plate-membrane with a non-deformable fixed central disk loaded by a uniformly distributed static load is considered in a linear formulation. On this basis, the extreme problem of determining the rational physical and geometrical characteristics of an elastic element from the condition of the maximum of the target function of the thrust (permutation) force with two coupling equations in the form of the classical Huber-Genke-Mises strength hypothesis and a geometrical relation limiting the membrane thickness in accordance with the known fundamental Kirchhoff assumptions of the technical theory of small plate bending is solved. To illustrate the proposed algorithm and calculation procedure, a numerical example of the selection of optimum parameters of a manganese steel diaphragm with given dimensions of thickness and outer radius is presented. The results of the work can be used in the process of designing high-precision membrane-type pressure gauges, widely used in mechanical engineering, aviation, instrumentation, and construction in the design of pressure tanks with controlled excess pressure of gas or liquid.

Comparative Assessments of At-Sea and Inland Low- and Medium-Pressure CO2 Transport

Developing cost-efficient systems for transporting CO2 is key to accelerating the deployment of carbon capture and storage. The present work explores the impact of reducing the pressure of tank-based inland and at-sea transport on their techno-economic performance. The study uses established techno-economic models for CO2 transport, adjusted with the most up-to-date knowledge on the costs of low-pressure containment and transport. In particular, the impact of cargo tank material and design on the transport costs show that low-pressure cargo tank systems can be 50% less expensive than medium-pressure systems if materials with similar price and strength can be used. This results in reductions in transport costs as high as 30% for long distances. This is partly driven by the currently suggested size limitation on medium-pressure shipping that limits its economies of scale. If this limitation is alleviated, the cost advantage of low-pressure shipping compared to medium-pressure is more limited (10–20%) although it remains advantageous. The same scaling effects on capacity were not found for truck and barge inland transport, thus yielding 1–10% cost reductions of low-pressure transport relative to medium-pressure transport. These results imply that future systems may combine medium-pressure inland and low-pressure at-sea transport and that efficient solutions connecting the two must be investigated.

Integration and Design of Cryogenic Hydrogen Fuel Systems for Sustainable Commercial Aviation

The transition to hydrogen-powered aircraft offers an opportunity to significantly reduce carbon emissions in commercial aviation. The use of renewable hydrogen in commercial aviation has the potential to significantly reduce the carbon footprint of the industry. Aviation currently accounts for around 3% of global carbon emissions, a figure that is projected to grow without the adoption of sustainable fuels like hydrogen [1]. Hydrogen can be stored as a compressed gas at high pressure and as a liquid at cryogenic temperatures. However, the unique properties of hydrogen, particularly its low density and cryogenic storage requirements need a complete redesign of aircraft fuel systems. The low density of hydrogen necessitates larger storage volumes compared to conventional fuels, and cryogenic storage requires maintaining extremely low temperatures to prevent boil-off, which can lead to significant fuel loss [2]. This research aims to develop innovative fuel system designs that can efficiently store and deliver cryogenic liquid hydrogen. Numerous tank designs including cylindrical, spherical, and double-walled configurations will be explored. Cylindrical tanks are commonly used for high-pressure gas storage and must be designed to withstand pressure loads effectively. Spherical tanks offer a lower surface area-to-volume ratio, which is advantageous for reducing heat transfer and boil-off. Double-walled configurations provide additional insulation and structural integrity, essential for maintaining cryogenic temperatures [3]. Additionally, effective heat management is crucial in hydrogen fuel systems. The research will explore strategies to recover waste heat from fuel cells or combustion processes, which can be utilized to improve overall system efficiency. This is particularly important in preventing excessive boil-off in cryogenic tanks, which can lead to increased pressure and potential safety issues. By conceiving aircraft designs optimized for either direct liquid hydrogen combustion or fuel cell propulsion, this research aims to create sustainable aviation solutions. Furthermore, this study will develop a detailed thermodynamic model to simulate the behaviour of cryogenic hydrogen fuel systems under various operating conditions, including heat transfer, phase changes and boil-off effects. The goal is to optimize the design and operation of hydrogen fuel systems to achieve maximum efficiency and safety. The findings from this research aim to provide a comprehensive framework for the future of hydrogen-powered commercial aviation. By addressing the unique challenges of hydrogen storage and fuel system design, the study seeks to contribute to the development of sustainable aviation solutions that can significantly reduce the carbon footprint of the airline industry.

Design and Development of a Stainless Steel Fermentation Tank for Palm Wine with Gravity Purification Construction

Tourism and culinary activities are increasingly integrated into wine tourism, a key segment of agricultural tourism. Palma wine, a traditional wine produced from the sap of palm trees (locally known as sagars), is a significant product for the Minahasa farming community in North Sulawesi. This study focuses on optimizing the fermentation process to enhance the quality of Palma wine by utilizing food-grade HDPE containers and a dual-role fermentation tank. The tank is designed to reduce dust content in the palm sap through an efficient mechanism while minimizing disruptions during the transfer of fermentation products. The research involves designing and testing fermentation tanks based on applied science and technology principles to improve purification processes and standardize effectiveness and efficiency measurements. Results demonstrate that the use of high-quality fermentation tanks enhances the purification process and ensures better-quality Palma wine, contributing to the development of local wine tourism and supporting sustainable agricultural practices.

Analysis of thermal and mechanical properties with inventory level of the molten salt storage tank in central receiver concentrating solar power plants

Molten salt thermal energy storage (TES) tanks ensure steady power output of concentrating solar power (CSP) plants; however, recent tank failures have highlighted the need for further analysis. Current studies primarily focus on analyzing the molten salt flow, heat transfer, and thermal efficiency. Additionally, research on the latest tank structures is limited and lacks newest experimental validation. This study measures temperature and molten salt inventory levels in the high-temperature tank at a 50 MW central receiver CSP plant, connected to the power grid in 2019. A multi-physics model was developed to evaluate thermal and mechanical properties of TES tanks by combining computational fluid dynamics and finite element modeling using real plant data. Heat loss, temperature, displacement, and stress distribution of the tank at different inventory levels were investigated. Results show that ambient air velocity near the tank roof reaches 2.14 m/s, much higher than 0.2 m/s near the wall. The temperatures of inventory fluid and tank are close, varying slightly at different levels due to thermal conduction and radiation. Because the heat loss strongly depends on temperature, the total tank loss remains nearly constant across inventory levels. Larger temperature gradients and thermal stresses are primarily localized along the tank floor edge and the air-salt interface. Notably, the maximum thermal stress at the tank edge is three times higher than that at the interface. The magnitude of total stress changes by less than 5 MPa with and without thermal load, indicating that high temperatures exert only a minor impact on tank stress. In contrast, thermal load significantly affects tank deformation, particularly at the roof edge, where values exceed 150 mm. Despite the large variation in molten salt levels, tank wall temperatures and displacements present a minor change, suggesting a weak correlation with inventory levels. The findings obtained in this study provide important insights on the TES tank that could be used to optimize tank design and operation strategies.

A new dynamic control strategy for a solar-driven absorption thermal energy storage system: Modeling and performance evaluation

Solar heating is a vital technology to promote the decarbonization of building energy supply systems. However, the mismatch between the intermittency of solar energy supply and the fluctuating heating demands poses significant challenges to its application. Current heat storage systems often exhibit low energy density, significant heat losses, and limited temperature regulation capabilities, which restrict their effectiveness in practical applications. This paper proposed a new real-time control strategy for a solar-driven absorption thermal energy storage system, integrated with an absorption heat pump, which can resolve the mutual constraints between solar energy utilization efficiency and the heating temperature, and then improve the system flexibility. The dynamic control strategy is implemented to manage concentration and temperature by regulating the inlet and outlet flow rates of three tanks, namely the absorbate tank, the weak solution tank, and the strong solution tank. A thermodynamic model is developed based on Aspen Plus and Matlab. Results show that within a 24-hour cycle, the system, driven by intermittent solar energy, can effectively meet the varying user-side heating demands through flow rate regulation. An optimized tank design, based on flow variation analysis, reduces the total volume by approximately 35 %. Additionally, the system can recover low-grade heat from the environment through the absorption heat pump, achieving an energy storage efficiency of 1.07 and an energy storage density of 56.13 kWh/m3. The proposed system and its dynamic control method are well-suited to intermittent solar energy, increasing the system flexibility, and thus expanding renewable energy utilization potential, especially those involving multi-energy complementary systems.

Design and simulation of variable LC tank based on MEMS technology for multi band applications

Design and simulation of variable LC tank based on MEMS technology for multi band applications

Analysis of convection and boil-off in multi-scale membrane LNG tanks under sloshing excitations

The marine storage and transportation of liquefied natural gas (LNG) in membrane tanks involves complex thermodynamic responses, significantly affecting system operation reliability. The study investigates the coupled problem of heat transfer and sloshing in LNG tanks through small-scale experiments and simulations. A tank partially filled with R134a was analyzed under various non-isothermal sloshing excitations to examine the free surface, flow, and heat transfer. Changes in fluid temperature, wall temperature, and heat flux were measured under different sloshing frequencies, amplitudes, and filling levels. A Computational Fluid Dynamics (CFD) analysis was performed, considering heat flow in the insulation layer and phase changes in the membrane tank. The tank was assumed to be vented. A Volume-of-Fluid (VOF) model with a dynamic mesh provided insights into the effects of sloshing on heat transfer and flow. Model feasibility was confirmed by comparing simulation results with fluid sloshing experiments. An extended sloshing Nusselt number was calculated, and a correlation formula related to sloshing conditions was developed, allowing for a quantitative assessment of enhanced heat transfer. Simulations explored evaporation characteristics in various scales of LNG tanks under static and sloshing conditions. The results showed that the evaporation rate of LNG increases as the tank scale decreases, with sloshing significantly impacting LNG storage and transportation. The study enhances the understanding of heat transfer and flow evolution in LNG tanks, improving the accuracy of evaporation models and providing insights for optimizing tank design and operation under sloshing conditions.

Comprehensive design and preliminary experiments of liquid hydrogen storage tank for trucks

As the global demand for lower carbon emissions intensifies, the deployment of medium and small-scale liquid hydrogen (LH2) storage tanks in heavy-duty trucking and aviation is expected to increase. However, heat leakage into these cryogenic vessels leads to a continuous increase in tank pressure, potentially resulting in sudden hydrogen release and other safety concerns. While horizontal LH2 tanks demonstrate greater suitability in the transportation sector compared to vertical tanks, investigations in this domain remain scarce. Research on horizontal tanks is crucial for safe and efficient storage. Understanding these dynamics is essential for predicting temperature and pressure changes during self-pressurization, ensuring safe liquid hydrogen storage. This study designed and built a 500-liter horizontal liquid hydrogen tank for vehicle fuel storage, following ISO 13985 standards to ensure practical applicability. The project encompassed material selection, structural design, and both stress and thermodynamic analyses. Preliminary experiments were conducted using liquid nitrogen as a substitute for liquid hydrogen. Experiments assessed tank heat leakage, vapor-cooled shield insulation performance, thermal stratification, lossless storage time, and pressure changes during self-pressurization and steady-state evaporation. Results validate the efficiency of our pressure vessel design method for complex conditions, enhancing understanding of self-pressurization and thermal stratification in horizontal tanks. The vapor-cooled shield reduced heat leakage into the tank by 22.7%, decreasing the daily evaporation rate under liquid nitrogen conditions from 1.87 wt% to 1.5 wt%. and maintaining an initial liquid level of 50% extended the lossless storage time to 50 h in the LN2 scenario. These findings offer valuable insights for assessing the performance of subsequent liquid hydrogen experiments.

Retrofitting of a hybrid propulsion shunting locomotive equipped with Fuel Cell and Metal Hydrides storage

Abstract The use of hydrogen as an energy carrier is more and more interesting in the current energy scenario due to the possibility of utilizing electrolysis as a large-scale energy storage solution for renewable energy plants and its versatility as a fuel in various applications, both stationary (hard-to-abate industries) and in transports. However, the use of hydrogen still presents technological challenges, particularly concerning its storage and transportation. The use of metal hydrides (MH) intermetallic compounds to store the gas helps to reduce the hazards and technological complexities that other storage systems (such as high-pressure compressed hydrogen or liquid hydrogen) may entail, allowing low pressure storage. These compounds are capable of absorbing hydrogen atoms into their interstitial lattice, releasing them once heated with a sufficient amount of heat. This study assesses the possibility of using (instead of a compressed hydrogen storage system) a metal hydride system onboard of a shunting locomotive (to be used in ports and interports) as part of a retrofitting process aimed at converting the locomotive itself to hydrogen, equipping it with a PEMFC driven power-train whose waste heat could be valorised to drive the management of MH discharge. Based on the locomotive’s characteristics and constraints (weights and size, amount of fuel to be stored onboard according to its mission profile), the amount of hydrogen that could be installed on the vehicle was assessed, looking at the feasibility of storing H2 on board via MH due to space and weight constraints. In this analysis, three different metallic compounds (LaNi5, TiFe, TiMn1.5) widely used in the field of metal hydrides, and various tank designs (which allow different heat exchange between the MH and the heat transfer fluid coming from the PEMFC) have been considered in order. The different tank layouts were compared to analyse the thermal management of the metal hydride discharge process through the recovery of waste heat from the locomotive’s power-train fuel cell, thus targeting solutions for the final MH tank sizing and design.

Machine learning-based prediction of seismic response of elevated steel tanks

Seismic response analysis assesses structural safety and integrity during earthquakes and guides design for optimal performance, compliance with regulations, and risk mitigation. This study proposes a novel approach utilizing machine learning (ML) techniques to predict the seismic response of elevated steel tanks accurately. ML is a powerful tool that can handle complexity, improve accuracy, provide data-driven insights, and optimize designs for predicting seismic responses of structures. Moreover, this study evaluates various ML models containing Random Forest, Support Vector Regression, Adaptive Boosting, LightGBM, Histogram-based Gradient Boosting, XGBoost, CatBoost, Bagging Regression, and Decision Trees to identify the most effective predictive model. In general, the developed ML-based predictive models provide a promising tool for engineers involved in the seismic design and retrofitting of elevated steel tanks, aiding in optimizing designs and enhancing structural safety and resilience against seismic hazards. As a result, the HGB model obtained the most suitable performance compared to other developed models with higher R2 and lower RMSE. In addition, a sensitivity analysis was performed based on SHAP values, and it was found that the height of the liquid and the intensity measure were the most influential variables in the seismic response of the tank.

Study on Mechanical Properties and Fatigue of Cold-rolled Steel Plate for Distribution Transformer

The oil tank steel plate of the distribution transformer is covered with welds, and the fatigue failure of the oil tank often occurs in the internal defects of fillet welds. Given the above problems, this paper puts forward the bearing capacity calculation formula of cold-rolled steel plate and carries on the force analysis of steel plate and the fatigue analysis of weld through finite elements. Based on the theory of plastic limit design, the ultimate flexural bearing capacity of the control section of steel plate members is proposed. The calculation formula of equivalent structural stress is given based on the calculation method of structural stress and linear elastic fracture mechanics, and the calculation method of fatigue life and fatigue cumulative damage is given. Then, the elastic-plastic equation is solved according to three criteria: Mises yield criterion, plastic flow criterion, and strengthening criterion. Based on the above numerical simulation analysis, the mechanical model of steel plate weld is constructed, the mesh is divided, the boundary conditions are restricted and the same load is applied. ABAQUS analysis results show that the stress distribution curve of the connector has a maximum value at X = 80 mm and X = 210 mm, that is, the top surface of the connector steel plate has an obvious stress concentration at 80 mm and 210 mm. When the length of the weld is not more than 60 times the size of the welding foot, the full section of the core plate will yield, and the maximum stress value of the weld element will not exceed the tensile strength value of the welding material. The error of the results calculated by the formula in this paper is mostly within 10%, and the rest is basically within 20%. Therefore, the bearing capacity formula of the steel plate in this paper has ideal calculation accuracy and can provide effective guidance for the design of distribution transformer oil tanks.

Flow Field Analysis within Industrial Quenching Tanks Operated with Aqueous Polymer Solutions in the Steel Industry

Abstract Quenching with polymer solutions for steel heat treatment offers adjustable performance and improved ecological impact compared to conventional water or oil quenching. The submersion cooling operation poses challenges due to the intense vapor/polymer film collapse on the component surface, potentially destabilizing batch components. Therefore, controlled recirculation is critical to preventing tank and specimen damage during cooling and ensuring effective steel hardening. However, flow structure analysis is often overlooked and disregarded in industrial tank design. Thus, this study evaluates the tank geometries of two partner industries to determine if they provide the necessary homogeneous flow for optimal quenching. The analysis combines experimental velocity measurements with a numerical model, with the identification of different flow intensity regions being the main outcome of this work. The results suggest that geometric modifications could improve flow recirculation, enhancing quenching performance.

Dynamic Behavior of Rectangular Tanks with Limited Freeboard Under Seismic Loads: Experimental, Analytical and Machine Learning Investigations

Abstract One of the most common types of fluid storage tanks are rectangular concrete tanks placed on the ground. Ensuring the seismic performance of these tanks is crucial as, besides damage and losses during a crisis, they can lead to other crises such as fires or toxic material leaks. One pivotal factor influencing the seismic behavior of these tanks is the height of the freeboard. A comprehensive understanding of how freeboard height impacts the impulsive and convective masses is essential for the effective design and dynamic analysis of rectangular tanks. While numerous numerical and experimental studies have explored this field, the influence of various filling levels, fluid properties, and tank geometries under seismic loading conditions requires further investigation. In this study, both an experimental model and a theoretical model were subjected to different tank fill levels, tank geometries, and various freeboard heights under the influence of different earthquake records. The results showed that tank height and geometry significantly affect the changes in impulsive and convective masses. Notably, in contrast to previous studies, our results demonstrate a nonlinear relationship between freeboard height and the variations in these masses. These new findings are crucial for refining current design practices and improving the resilience of rectangular tanks in earthquake-prone regions.