Tank Volume Research Articles

StRaWHAT: A stochastic rainwater harvesting assessment tool for direct quantification of rainwater harvesting system performance

Rainwater harvesting (RWH) contributes to reduced flooding and relief of demand on water supply systems and is instrumental in sustainable development. The conventional analytical probabilistic approach for RWH has a limitation of requiring an assumption of the initial storage condition which may cause overestimation or underestimation of the system's performance. By deriving the average storage volume of the RWH tank to get rid of such an assumption, a stochastic rainwater harvesting assessment tool (StRaWHAT) which is comprised of a set of closed-form analytical equations was developed and proposed for use in directly quantifying the hydrological performance statistics of RWH systems. The accuracy of StRaWHAT was verified by comparing its results with those obtained from continuous simulations based on mass balance principles for a large number of design scenarios with different climate conditions (6 cities in China and the US), storage capacities (1–20 m3) and water use rates (0.5, 1, 1.5 or 2 m3/day). Close agreements (NSE = 0.984, RMSE = 0.022, and CORR = 0.995) between StRaWHAT and continuous simulation results illustrated that StRaWHAT can provide accurate results for all types of system configurations. Extensive example case studies were carried out for RWH systems located in six cities in China and the U.S. Different types of applications were also illustrated. Overall, the proposed StRaWHAT was proved to be a computationally efficient and ease-to-use tool for directly assessing the hydrological performance of RWH systems.

Multi-objective particle swarm optimization algorithm for data acquisition and system characteristics research of phase change thermal storage heat pump water heaters

In order to understand the multi-objective particle swarm optimization algorithm for data collection and system characteristics research of heat pump water heaters, the author proposes a multi-objective particle swarm optimization algorithm for data collection and system characteristics research of phase change thermal storage heat pump water heaters. The author first introduced the working principle of the phase change heat storage heat pump water heater, and then conducted a comparative experimental study on the performance of two types of heat pump water heater systems using pure paraffin phase change heat storage and water storage. They compared and analyzed the heat storage process, condensation heat recovery rate of the heat storage box, and comprehensive energy efficiency coefficient of the system under the refrigeration and heat recovery mode of the two types of heat pump water heater systems, on this basis, measures were proposed to improve the performance of pure paraffin phase change thermal storage hot water systems. At long last, the examination of exploratory information shows that the Rx of the water warm capacity framework is around 6% higher than that of the stage change warm capacity framework, and the framework COPt is likewise 20% higher than that of the stage change warm capacity framework, from this, it tends to be seen that the stage change heat capacity box has unfortunate intensity move proficiency, prompting a lessening in the presentation of the intensity siphon water radiator framework. Contrasted and customary water stockpiling heat siphon boiling water frameworks, unadulterated paraffin stage change capacity heat siphon high temp water frameworks lessen the volume of the intensity stockpiling tank, and the framework works somewhat flawlessly during the intensity stockpiling process. However, the system?s overall energy efficiency is impacted by the heat storage tank?s poor heat exchange effect and relatively low condensation heat recovery rate. The intensity move of the intensity stockpiling box can be upgraded by finning the winding curls in the intensity stockpiling box, embedding aluminum foil, adding extended graphite, and different measures to further develop the buildup heat recuperation rate, subsequently working on the general execution of the framework.

Microbial Formation on Different Biomedia Surface for Wastewater Treatment

Even though commercial plastic media such as Cosmoball successfully treated municipal wastewater without clogging, its inadequate surface area prevents its use for high biofilm growth rates. This study compares microbial formation on the activated carbon (AC)-coated and non-coated Cosmoball media by submerging four activated carbon AC-coated Cosmo balls and non-coated Cosmo balls in five-liter beakers containing municipal wastewater. The researchers then analyzed the surface morphology of the biofilms on the coated and non-coated surfaces and applied the next-generation sequencing (NGS) technology to the ecology of microbial-mediated processes. By Day 11, the AC-coated media showed a biofilm coverage of 95%, whereas the non-coated media had a biofilm coverage of about 70%. The research has demonstrated that the coated media has a four times higher surface area, thus saving as much as 50% of the aeration tank volume.

TRANSIENT ANALYSIS OF LIQUID-HYDROGEN TRANSFER IN CRYOGENIC STORAGE TANKS

Efficient transfer of liquid hydrogen is critical for a myriad of processes in terrestrial and extraterrestrial applications. The objective of this study is to model and quantify the amount of liquid parahydrogen vaporized during a discharging/charging process in a cryogenic storage system. The effects that are included include geometrical effects (storage tank volume), two-phase compressible flow, choking/unchoking, and wall-fluid heat transfer. A brief description of other physical boil-off mechanisms is also presented. This study provides a foundation for applicationspecific optimization. The storage system studied comprises two interconnected tanks whose transfer line has a variation in the flow area. This simulates current liquid-hydrogen storage and transportation systems. The model tracks the temperature- and pressure-time histories of liquid hydrogen as it flows between storage tanks, in both the choked and unchoked flow regimes. The transfer of liquid is induced solely by the pressure differential that exists between the two storage tanks. An iterative technique helps account for choking, which is likely to exist at the throat in two-phase flow. Cases of zero and infinite tank-wall thermal mass are also discussed. By analyzing the behavior of fundamental variables during the transient transfer of liquid hydrogen, boil-off losses may be minimized if the variables with the greatest effect on boil-off losses are controlled.

Deformation model for hollow cylindrical-shaped variable volume tank

Deformation model for hollow cylindrical-shaped variable volume tank

Exploring Bio Augmentation as a Sustainable Approach for COD Reduction in Palm Oil Refinery

Purpose: This study aimed to investigate the effectiveness of Bioaugmentation Technology in addressing elevated levels of Chemical Oxygen Demand (COD) and reducing sludge volume in the aeration tank of a Palm Oil Refinery located in Kalimantan Island, Indonesia. In addressing these concerns, the study employed Bioaugmentation Technology, specifically tailored for the treatment of palm oil mill effluent in both aerobic and anaerobic ponds, with the aim of expediting the breakdown of organic compounds.
 Methodology: The research focused on evaluating the impact of this technology on organic degradation and sludge reduction in comparison to conventional treatment methods. Conventional Palm Oil Mill Effluent (POME) treatment systems typically utilize large-volume sequential pond arrangements with extended hydraulic retention times (>90 days), resulting in inefficient organic degradation. Conversely, the Bioaugmentation Technology utilized in this study emerged as a natural, non-toxic, and easily implementable solution to operational challenges faced by these systems.
 Findings: The technology facilitated the rapid breakdown of organic compounds, leading to a reduction in COD and subsequently, a decrease in sludge volume. Based on the observed positive outcomes, it is recommended to consider Bioaugmentation Technology as a viable and efficient solution for POME wastewater treatment in palm oil refineries.
 Unique contributor to theory, policy and practice: Its capacity to enhance organic degradation, reduce sludge volume, and improve overall treatment plant efficiency suggests its potential as a valuable complementary technology to existing treatment methods in similar operational conditions.

Numerical modeling and optimization of thermal insulation for liquid hydrogen storage tanks

Liquid hydrogen storage is one of the effective hydrogen storage methods due to its high density of 70.8 kg/m3 compared to gaseous hydrogen of 0.0838 kg/m3 at atmospheric pressure. Liquid hydrogen requires cryogenic storage technology, which minimizes heat flux by stacking multiple insulation layers in a high vacuum (10−1–10−5 Pa). However, large-scale tanks use a medium vacuum (100–10−1 Pa) to reduce maintenance expenses. Solid insulation is applied to prevent liquefaction of residual gas up to 150 K, followed by the stacking of multilayer insulation (MLI) with a vapor−cooling shield (VCS) to minimize the insulation thickness. In this study, a numerical model was developed to calculate the heat flux of a storage tank based on the physical tank shape. The insulation thickness was also optimized for two insulation systems (solid insulation + MLI and solid insulation + MLI + VCS). Optimal VCS placement on solid insulation, determined through sensitivity analysis, reduces 64.2 % of MLI layers under 5 Pa vacuum pressure. Total insulation thickness reduction of 51.4 % at 1 Pa vacuum pressure was obtained based on a hydrogen storage tank volume of 4200 m3. The effects of insulation thickness reduction are remained even when the vacuum pressure is increased to 5 Pa.

Development of low-cost rainwater harvesting to support on-site water supply in rural Tajikistan

Farmers in remote, arid areas, far from available water sources, need affordable water solutions for household and livestock use. In this study, the water needs and potential for rainwater harvesting (RWH) in the Kysylsu River Basin are estimated at different altitudes. The mean annual net rainfall depth varied from 545 to 900 mm. With an average roof area of 550 m2, 211 m3 to 344 m3 rainwater can be harvested for dry and wet years respectively. Based on the estimated water demand and rainfall deficit, the average household need was estimated to be 100 m3. For a low-cost water storage solution, we tested different types of waterproof materials to replace smaller 12-18 m3 concrete tanks commonly used in the region. Soil pits lined with 0.3 mm double layer polyethene (0.6 mm in total) was the best solution for 5 m3 volume tanks in terms of the costs and durability and 0.8 mm double layer polyethene (1.6 mm in total) was ideal for sealing 10 m3 volume tanks. This study demonstrates the efficiency of the system for improved livelihood of the families through rain harvesting.

Flash boiling and pressure recovery phenomenon during venting from liquid ammonia tank ullage

Liquid ammonia stored at elevated pressures undergoes phase change during tank venting. The paper describes a CFD model able to reproduce the INERIS experiment performed using 12 m3 volume tank when 300 kg of ammonia were vented during 460 s from the ullage through the pipe to the atmosphere. The model is based on the volume-of-fluid method combined with Lee’s model for mass transfer between phases. Extensive calibration trials were conducted to examine the impact of surrounding temperature conditions. It allowed to establish the range of time relaxation parameter values of Lee evaporation-condensation model specific for liquid ammonia tank venting. Simulations reproduced accurately the experimentally measured final pressure in the tank and the amount of ammonia released during venting. Liquid ammonia boiling is triggered by reduction of pressure and takes place throughout the liquid causing the pressure recovery phenomenon. Numerical simulations demonstrated that pressure recovery phenomenon is driven by the characteristic time delay associated with the rise of vapour bubbles generated by flash boiling and the subsequent release of evaporated ammonia into the tank ullage space. The developed CFD model can be used as a contemporary tool for safety engineering and development of tank management strategies for liquid ammonia storage.

Survival and moulting rates of larvae of Callinectes sapidus Rathbun, 1896 under different environmental circumstances (Brachyura, Portunidae)

Abstract This study investigated the well-being and survival of larvae of the blue crab, Callinectes sapidus, under the influence of several abiotic and biotic factors, in order to collect relevant data for optimizing the larval period in the culture of this species. Aspects tested and examined were primarily: water volume, stocking density, salinity, (frequency of) moulting, starvation, mortality, cannibalism, behavioural aspects (e.g., mobility, intraspecific aggression), larval development, as well as the influence of ground colours. All aspects appeared to influence the duration and success of the larval period, from zoea-I to megalopa, but the main difference was observed to be related to the (water) volume of the culture tanks.

Experimental Evaluation of a Pilot-Scale Thermocline Thermal Energy Storage Combining Latent and Sensible Materials

This work presents the experimental evaluation of pilot-scale thermocline that integrates a layer of phase change material (PCM) at the top of a sensible heat storage material in a thermocline thermal energy storage (TES) tank. The TES is integrated to the MicroSol-R parabolic trough pilot plant at the PROMES research facility in Odeillo, France. The tank is filled with alumina spheres as sensible heat storage. The PCM is NaNO3 encapsulated in stainless steel horizontal tubes that fill about 5.5% of the tank volume. The charge is evaluated at three mass flow rates 2600, 3000, and 3900 kg/h at two different operating temperature ranges 285-315 ºC and 295-330 ºC. The discharge is studied at three mass flow rates 1600, 2000, and 3000 kg/h from 315 to 220 ºC and 330 to 225 ºC. The performance of the TES is analyzed with two main indicators: the thermocline thickness and the efficiency during the charge and discharge. The results indicate that lower mass flow rates during the charging process result in smaller thermocline thickness. Similarly, during discharge, the thermocline thickness reduces with lower discharge rates. Efficiency evaluation during discharge suggests that an optimal flow rate could be achieved.

Techno-economic analysis of type III and IV composite hydrogen storage tanks for fuel cell vehicles

The hydrogen gas storage tank market includes passenger cars and heavy-duty trucks. However, there is insufficient economic analysis of these tanks, which is the key element for achieving market expansion. Theoretical studies have investigated the cost of carbon composites in automotive and aerospace applications and hydrogen storage tanks. However, there is insufficient analysis based on actual technological and cost data. Moreover, there is limited analysis of the material, labor, and expense costs and equipment investments based on production quantities. The objective of this study is to analyze the costs related to hydrogen tanks in passenger cars and heavy-duty trucks on the basis of the manufacturing technologies, tank volume, type, and annual production. Furthermore, this study uses a cost – profit modeling approach to identify the cost, price, investment, and key cost drivers and provide target costs, effective manufacturing technologies, and strategies to meet the demands of the hydrogen tank market.

Delayed and Partial Mixing Method of Operating Multi-Tank Redox Flow Battery Systems

To reap the benefits of conventional single and multi-tank redox flow battery (RFB) fluid systems, we investigate a delayed and partial mixing methodology for operating RFB tank systems to maximise electrolyte utilisation and storage capacity. The method modulates an optimised mixing timeframe and mixed amounts of momentarily (un)circulated electrolytes in two vertically separated tank sections. The gravity-assisted mixing between the tank sections achieved by siphon or automatic valve ensures continuous uninterrupted flow occurs in a single direction within the cell while lowering additional auxiliary components/energy and system complexity/cost. We applied a detailed Multiphysics simulation of a test vanadium RFB cell to demonstrate the methodology and its capabilities - especially for larger tank volumes. Significant concentration overpotential reduction with the delayed and partial mixing leads to an increment in discharge capacity and energy efficiency up to 6.5% and 2%, respectively, compared to the conventional single tank system. The practical applicability of the investigated system was also discussed as promising for commercial RFB deployments.

Modeling and simulation of dynamic characteristics of a green ammonia synthesis system

Green ammonia production system driven by renewable electricity will be under frequent dynamic operation due to the fluctuation of renewable energy. The nonlinear dynamic model of a green ammonia synthesis system is developed and the dynamic responses of PEM (proton exchange membrane) electrolysis subsystem, PSA (Pressure swing adsorption) subsystem and ammonia synthesis subsystem during the start-up process and under the fluctuation of renewable electrical current are analyzed. The start-up dynamic results show that the hydrogen production rate of PEM electrolysis system is positively correlated to the current. The nitrogen output of PSA system is affected by the adsorption time, adsorption pressure, bed length, and air velocity. A start-up period of 300 min from the warmed-up state to the design state can maintain the temperature rise rate of the ammonia synthesis reactor at approximately 40 K/h. The dynamic results under step fluctuations of electrical current show that the PEM electrolysis subsystem and the PSA subsystem response fast compared to the ammonia synthesis reactor and buffer tanks. Using large buffer tanks to smooth the fluctuation allows the system to slide with the variation of renewable current to some extent, resulting in a higher outlet ammonia fraction when the current increases. Different volume ratios of the hydrogen tank to the nitrogen tank volume can lead to different variations of the hydrogen/nitrogen ratio. PID controllers can effectively maintain the bed temperatures, hydrogen/nitrogen ratio, and pressure of the ammonia synthesis reactor at their set points despite fluctuations in renewable electrical current. Buffer tanks are necessary to compensate for the imbalance between the flow rate fluctuation caused by current change and the flow rate regulation caused by PID controllers.

Rollover Prevention Model for Stratified Liquefied Natural Gas in Storage Tanks

At least 24 liquefied natural gas (LNG) rollover incidents have been reported since 1960. During rollover, because of the heat ingress through the tank walls, a stratified LNG may be suddenly homogenized while releasing massive amounts of vapor. It can result in an overpressure in the tank and significant amounts of potentially explosive LNG vapor being vented out. Both of these factors represent considerable hazards. Rollover is a physical mixing process in a single tank with two or more different cells of LNG of different compositions, temperatures, and densities that can manifest in large boil-off rates. It can exceed venting equipment capacities, and vapor pressure in tank increases rapidly and in extreme cases can lead to tank damage. This paper presents numerical approach for determination of time of rollover occurrence in storage tank. The presented model is based on the energy balance of the stratified cryogenic liquid and the gas phase as separate three thermodynamic systems in the storage tank. As a result of proposed model, for the adopted assumptions and cylindrical tank volume of 78,500 m3, the approximate time of the rollover occurrence was determined for two cases. In the first case, for heavier LNG, the rollover phenomenon will occur 193.25 h after the start of the calculations from the assumed initial conditions. In the second case, for light LNG with a higher initial liquid level in the tank, the rollover will occur after 150.25 h.

Research on renewable energy coupling system based on medium-deep ground temperature attenuation

Medium-deep geothermal has large reserves, a high temperature, a high heat flow density, and other characteristics, but the traditional medium-deep ground heat pump system have long relied on heating from the ground, and soil temperature decreases annually. Using a community building heating system as an example, from a point of view of heat accumulation or not, this article examines the design of a photovoltaic photothermal coupled medium-deep ground source heat pump system (PV/T-GSHP) and a photovoltaic-assisted medium-deep ground source heat pump coupled air source heat pump system (PVGSHP-ASHP). First, the operational performance of a typical GSHP system was compared to that of the PV/T-GSHP and PVGSHP-ASHP systems, both of which were built using TRNSYS. Second, the energy balance and electrical consumption of each system were compared. Finally, the effect of the PV/T-GSHP system’s key parameters and the different ASHP load ratios in the PVGSHP-ASHP system on soil temperature were analyzed. The results showed that after 20 years of operation, the average soil temperature decreased from 38.29 °C to 36.89 °C for the GSHP system, resulting in a decrease in the performance coefficient of the ground source heat pump and the system performance coefficient. The PV/T-GSHP system can address the issue of declining soil temperature with an increase in soil temperature of 0.09 °C. The PVGSHP-ASHP system can mitigate the issue of decreasing soil temperature. The PVGSHP-ASHP system is better than the PV/T-GSHP system in terms of electricity economy. In the PV/T-GSHP system, the larger PV/T component area of similar structures, the smaller flow rate of the heat collector pump, and the volume, inclination, and set temperature of the heat storage tank that are more suitable for the system can achieve higher soil temperatures. As the air-source load ratio increases, the rate at which the soil temperature in the PVGSHP-ASHP system decreases progressively decelerates.

Optimization of the accumulator tank filling modes of the xenon feed system for electric propulsion system

The object of the study in this work is pressure spikes in the accumulator tank of the xenon feed system for electric propulsion. The presence of significant pressure spikes in the accumulator tank of the feed system causes a change in the mass flow and, accordingly, a significant deterioration of the thruster parameters - thrust, specific impulse and efficiency. The problem that was solved in this work is to find ways to reduce pressure spikes while minimizing the volume of the accumulator tank without using additional elements. The analysis of literary sources showed that the specified problem is typical and has not been solved for small-volume accumulator tanks yet. To solve this problem, theoretical and experimental determination of pressure spikes that occur during the work on feedback from sensors was carried out, and an improved method of filling the accumulator tank was proposed. As a result of research, it was determined that pressure spikes that go beyond the permissible range (±3 %) appear at an inlet pressure of 3.5 MPa. With an increase of inlet pressure, the pressure spikes also increase. As a result of research, it was found that for an inlet pressure of up to 3 MPa, it is appropriate to work on feedback from pressure sensors. For pressure values from 3 to 6 MPa, it is necessary to use the experimentally obtained formula to determine the accumulator tank filling time. For a pressure of more than 6 MPa, it is necessary to work in the bang-bang mode. The research made it possible to determine the optimal modes of filling the accumulator tank. Presented modes allow to use a small-volume accumulator tank with the minimization of the valve activations number, in which stable operation of the thruster is maintained. The conclusions obtained as a result of the research can be useful for most developers of feed systems for electric propulsion.

Energy saving potential analysis of a short cycling industrial air compressor in a marine equipment manufacturing plant in Türkiye

Compressed air systems are recognised as significant energy users and are characterised by their notably inefficient energy consumption. This ensures their significance and potential for decarbonisation through cleaner and more responsible energy consumption in manufacturing facilities, such as marine equipment manufacturing plants in the shipbuilding industry, in order to address the various economic and regulatory challenges related to energy use and climate change. In the relevant literature, there are numerous studies on various energy-saving measures for compressed air systems; however, none concentrates on the problem of short-cycling phenomena and associated energy-saving potential. In this study, using a novel and systematic energy audit methodology, a detailed energy audit of a rotary-type screw air compressor was conducted at a marine equipment manufacturing plant in Türkiye. The systematic energy audit methodology was based on the measurement of power consumption and the evaluation of various operation parameters to assess the existing performance of the compressor, including compressed air demand, compressed air production, cycle speed, air tank volume, specific capacity, and duty cycle. The audit results revealed that the air compressor was short cycling, resulting in excessive energy consumption. Comprehensive technical and economic assessments were conducted to determine the root cause of the compressor's short cycling and to identify energy-saving potentials. It was determined that the compressor was oversized relative to the plant's compressed air demand patterns, while the air tank was inadequately sized, causing the compressor to engage in short cycling. To replace the existing short-cycling compressor, a scenario analysis revealed that the deployment of an optimised system consisting of a fixed-speed baseload compressor and a variable-speed trim compressor can reduce the plant's energy consumption for the compressed air system by a significant 73%. This results in annual energy savings of 74,160 kWh, annual cost savings of €9.373,8, and an annual reduction of approximately 49,9 tonnes of carbon emissions. This application requires an initial investment of €24.280 and is anticipated to redeem itself in 2,2 years. Moreover, it is anticipated to generate a net present value of €147.602 over its 20-year lifespan.

Performance Evaluation and Optimal Design Analysis of Continuous-Operation Solar-Driven Cooling Absorption Systems With Thermal Energy Storage

Abstract A solar absorption cooling system consisting of a flat plate collector, thermal energy storage tank, and absorption chiller is analyzed in this work. A dimensionless model is developed from the energy balance on each component and the chiller’s characteristic performance curves. The model is used to determine the interaction and influence of different parameters such as tank size, solar collector area, chiller size, cooling load, cooling temperature, heat loss, and mass flow rates on the performance. From the analysis, smaller solar collector areas are required for lower cooling loads and smaller tank volumes. A specific cooling load of 1 × 10−5 will require a specific solar collector area between two and six times larger, depending on the initial tank temperature, than the area required for a baseline system that considers typical commercial design and operation parameters. A similar behavior was observed for the specific tank volume. For the baseline system, the minimum specific area of the collector of 9.57 is achieved for an initial tank temperature of 1.19. For a cooling load of 1 × 10−5, the optimum initial tank temperature will be 1.11 that results in a minimum specific solar collector area of 25.26. A specific tank volume of 4 × 10−4 will also have an optimum initial tank temperature of 1.11 that minimizes the specific solar collector area to a value of 28.18. The approach and analysis in this work can be used to determine design parameters for solar absorption cooling systems based on a proper relation among system’s dimensions to achieve optimum operation.

Effects of Al powder on the reaction process and reactivity of B/KNO3 energetic sticks

Boron/potassium nitrate (B/KNO3) is a type of critical energetic composite material (ECM). However, the inert oxide layer on the B surface of B/KNO3 hinders the contact between pure fuel and oxidant, thus limiting energy release This limitation could be eliminated by adding highly reactive Al powder. To discern the effects of Al powder size on the reaction process and reactivity of B/KNO3, this study prepared Al/B/KNO3/polyvinylidene fluoride (PVDF) energetic sticks using the direct ink writing (DIW) technology. This study characterized the macroscopic morphology and structure of the energetic sticks using a laser scanning microscope and a scanning electron microscope, examined the reaction process of the composites using a differential scanning calorimeter and a thermogravimetric analyzer, and observed the flame propagation behavior of energetic sticks and energetic architectures using a high-speed camera. Furthermore, it tested the pressure output characteristics of the energetic composites using a closed volume tank. The results show that adding Al powder can improve the combustion efficiency of B/Al composite fuels and reduce the agglomeration of the combustion products. The Al powder with various particle sizes affects various reaction stages of the composite. The combustion and pressure output tests suggest that adding Al powder with a particle size of 1 μm yielded high reactivity and that flame jump propagation appeared in energetic architectures when the channel spacing was below 10 mm. These findings provide a guide for modifying the B/KNO3 energetic composites and regulating the reactivity of energetic sticks.