Storage Volume Research Articles

A Fully Printable and Integrated System with Long-Term Stability for Versatile and Multimodal Perspiration Tracking.

Real-time and continuous monitoring of physiological status via noninvasive sweat sensing shows promise for personalized healthcare and fitness management. However, the largely varied perspiration rates in different body statuses introduce challenges for effective sweat collection and accurate sensing. Herein, a fully printable strategy was developed to realize fully integrated patches for wireless sensing of sweat biomarker levels and perspiration rates with desirable stability and versatility. The printable calcium sensors with modified ion-selective membranes displayed an ultrawide linear range of 0.1-100 mM and a long-term stability with minimized drift down to 0.083 mV/h for around 40 h. Moreover, the microfluidic channels in versatile configurations were capable of a minimum sweat rate monitoring of 0.5 μL/min and a large sweat storage volume of up to 200 μL. The as-proposed fully printable sensing platforms provide high compatibility for sensor integration to achieve versatile perspiration tracking and comprehensive health monitoring.

Techno-economic optimization and feasibility of PCM-based seasonal thermal energy storage systems for district heating and cooling

Phase change materials (PCM) are an attractive seasonal thermal energy storage solution for load shifting due to relatively high energy density. Nevertheless, the choice of the right design parameters, such as storage size and phase-change temperature, is nontrivial, as these are tightly linked to the expected seasonal operation of the storage. This paper presents a combined design and operation optimization framework for sizing PCM-based seasonal thermal storage, which can capture dynamic behaviour of the storage in sensible and latent phases, and its impact on the efficiency of connected heat pumps and chillers. The proposed method, formulated as a mixed integer quadratically-constrained programming problem, was applied to a case study of heating-dominated district. It was found that the optimal PCM melting temperature equals to the heating demand supply temperature, thus removing the need of a heat pump to discharge the storage. The optimal operation of storage requires a full charging and discharging cycle of both latent and liquid phase. Higher CO2 emission price does not lead to a significant reduction of CO2 emissions, but the storage size does, leading to a higher heating coverage ratio of the storage, and consequently CO2 emissions and cost savings, which can be further enhanced with PV integration. The economic analysis indicates that, unless other benefits such as storage volume reduction are accounted for, PCM cost should drop by a factor 4 to make this solution economically viable for seasonal storage.

Optimization of a finned multi-tube latent heat storage system using new structure evaluation indexes

The latent heat thermal energy storage (LHTES) is one of the most promising ways of storing solar thermal energy. Since the thermal conductivity of phase change materials are low, traditional shell and tube heat exchangers tend to develop dead zones. Therefore, structural optimization is essential, and a finned multi-tube design is recommended. In this work, nineteen structures for a heat storage tank are designed to explore the influence of different specifications of heat exchange tubes and fins on heat storage/release performance. After establishing 3D physical models, ANSYS/Fluent simulation and a two-step optimization for charging and discharging processes were conducted. Among these structures, N3-M3-D10.2 emerged as the most efficient during charging process in terms of reducing the complete melting time by 25 % and increasing the 3-h heat storage volume by 2.95 times; however, it shows low performance during discharging process, especially with a 2.24 times non-uniformity factor. In the four preferred structures, the benefit-to-cost ratio of N3-M3-D10.2 is 48 %–86.6 % higher than that of the others. The results also show that the number of tubes and fins are negatively related to the melting rate, and positively related to the solidification rate. Moreover, the influence of fin diameter is greater than that of fin number and tube diameter on heat transfer rate. The novelty of this work is not only lies in both considering the charging and discharging processes, but also in using dimensionless normalized indexes and different weights based on customers’ actual requirements for optimization.

Transient pressure prediction in large-scale underground natural gas storage: A deep learning approach and case study

Large-scale underground natural gas storage (UNGS) facilities typically allocate only one month annually for well shut-in to facilitate pressure build-up. This limited well shut-in period affects the subsequent pressure measurements and evaluation of gas storage capacity. This study proposes a novel workflow to directly predict the transient pressure behavior of UNGS during pressure build-up without requiring additional well shut-in operations. The proposed workflow uses the gas injection-withdrawal rate as a dynamic input feature for a deep learning model, with reservoir pressure as the output feature. An enhanced WA-BiLSTM model integrates multiple physical mechanisms and advanced optimization algorithms. The model achieves mean squared error (MSE) of 2 × 10-3, which is less than 5 % of traditional model's results. Field data from the largest Hutubi UNGS exhibit a prediction accuracy of 99.0 % during the well shut-in phase. High-precision prediction results with low MSE ensure the reliability of pressure derivative data. By analyzing the predicted pressure data, the actual gas storage volume is 104.75 × 108 m3, accounting for 97.9 % of the facility's designated storage capacity.

Performance analysis of a molten salt packed-bed thermal energy storage system using three different waste materials

Concentrated Solar Power (CSP) is a critical technology for the renewable energy transition, offering high power output at elevated temperatures. However, further integration of CSP plants requires a reduction in investment costs. This study investigates the use of cost-effective, sustainable, waste-based TES materials—such as Electric Arc Furnace Black Slag (BS) and Tundish (TN) from the steel industry, as well as Demolition Waste (DW) from urban regeneration projects—as packing materials in TES systems to reduce the capital expenditure of CSP plants. A One-Dimensional Continuous Solid Phase (1D-2P) model was employed to evaluate and compare the performance of DW, TN, and BS. The results revealed that all materials demonstrated comparable properties, with TN exhibiting the highest energy storage capacity (44.7 kWh) and energy storage density (296 kWh/m³). With high utilization rates of 73–75 %, waste-based TES systems show strong potential for application in CSP plants. The TES systems were scaled for a 110 MW CSP plant, which currently operates with a 2-tank molten salt TES system providing 4648.4 MWh of storage capacity. TN required the smallest storage volume of 22,273 m³ for the 110 MW CSP plant. The reduction of molten salt usage by up to 31,000 tons in the waste-based packed-bed TES system could significantly enhance the economic feasibility of CSP plants.

Multi-objective optimization of airfoils with integral tubular high-pressure tanks for hydrogen storage

Reducing the environmental impact of air transport is one of today's most important challenges in aviation industry and research. A promising key enabler is the use of hydrogen as an alternative to fossil fuels. The development of hydrogen-powered aircraft poses new engineering challenges due to its low volumetric energy density requiring high-pressure or cryogenic storage. If the volume in the wing shall be further used for storing hydrogen under high pressure, new demands arise to airfoil design. The present work focuses on this issue by presenting a multi-objective optimization approach aiming for airfoils with both low drag and high volume for internal tubular high-pressure tanks. This allows to directly address the new design objective and to find novel airfoil shapes providing the best compromise between aerodynamic efficiency and high storage volume for pressurized hydrogen. The resulting optimization problem is solved using Evolutionary Algorithms. For an efficient aerodynamic evaluation, the open source viscous-inviscid panel method XFOIL is used. An application example, based on the flight conditions of a general aviation aircraft, demonstrates the applicability of the method. Comparisons of the resulting aerodynamic characteristics obtained by XFOIL with RANS simulations confirm the feasibility of the results.

Experimental study on pressure drop and ice blockage characteristics of ice slurry flow in big-diameter pipes

Ice slurry utilization in district cooling brings about attractive reduction in both the storage volume and transportation power of the cold thermal energy. However, the ice slurry flow characteristics, particularly in big-diameter pipes, remains unclear, hindering the application of ice slurry in large-scale district cooling systems. This paper prepared the ice slurry from pure water without any additives to experimentally study its flow characteristics in big-diameter pipes, including DN50, DN80, DN100 and DN190 pipes. The normalized pressure drops and friction factors have been obtained at various velocities and ice fractions. Generally, the pressure drop characteristics did not conform to the Blasius correlation which could predict the single-phase flow until the Reynolds number exceeded a certain threshold, known as the transition Reynolds number. The transition Reynolds numbers were in the range of 3.91 × 104-6.77 × 104 depending on the ice volume fractions ranging from 5% to 21% in the present study. Some visualization measures have been employed to help to observe the flow pattern and confirm the occurrence of ice blockage which was found nowhere but in the branches and expansion. The ice blockage occurred intermittently in the branches, whereas it was irreversible in the expansion. The critical velocity at which the ice blockage began to occur was quantitatively determined, which increased with increasing the ice volume fraction. This study provides a guide for evaluating the pump power and transportation safety of the ice slurry flow in big-diameter pipes.

Optimizing Underground Natural Gas Storage Capacity through Numerical Modeling and Strategic Well Placement

This study focuses on optimizing the storage capacity of an underground natural gas storage facility through numerical modeling and simulation techniques. The reservoir, characterized by an elongated dome structure, was discretized into approximately 16,000 cells. Simulations were conducted using key parameters such as permeability (10–70 mD) and porosity (12–26%) to assess the dynamics of gas injection and pressure distribution. The model incorporated core and petrophysical data to accurately represent the reservoir’s behavior. By integrating new wells in areas with storage deficits, the model demonstrated improvements in storage efficiency and pressure uniformity. The introduction of additional wells led to a significant increase in storage volume from 380 to 512 million Sm³ and optimized the injection process by reducing the storage period by 25%. The study concludes that reservoir performance can be enhanced with targeted well placement and customized flow rates, resulting in both increased storage capacity and economic benefits.

Institutional Conversion to Energy-Efficient Ultra-Low Freezers Decreases Carbon Footprint and Reduces Energy Costs.

Introduction: The storage of biospecimens is a substantial source of greenhouse gas emissions and institutional energy costs. Energy-intensive ultra-low temperature (ULT) freezers used for biospecimen storage are a significant source of carbon emissions. ENERGY STAR-certified ULT freezers have the potential to decrease the carbon footprint. Objective: Quantify the impact of an institutional-scale freezer conversion program on carbon emissions and energy costs. Methods: A ULT freezer energy use prediction model was developed to identify and replace the most inefficient freezers in the research building for this pilot, and eventually institution-wide. Multiple linear regression factors included the number of years of use, storage volume, and ENERGY STAR certification status. Electrical usage and carbon emissions were quantified before and after replacement with ENERGY STAR models. Logistical methods were developed to decrease the risks of exposure of frozen samples to ambient temperature during content transfers. Institution-wide energy costs were derived by converting electrical burden to electrical costs. Carbon footprint assessment from ULT freezer operation was computed using the U.S. EPA Greenhouse Gas Equivalencies Calculator. Results: The pilot project revealed an annual reduction of 310,493 kilowatt hours of electrical usage, equivalent to 134 metric tons of carbon emissions. Annual electrical costs were reduced by $55,889 resulting in an 8-year payback on the initial investment. Using the pilot results, we modeled the benefit of the freezer exchange across the entire institution. The modeling predicted that conversion of the institution's remaining 1119 conventional ULT freezers to ENERGY STAR models would lower annual electrical usage by 7,911,549 kilowatt hours (3423 metric tons of carbon emissions), resulting in savings of over $1.4 million annually. Conclusion: Our methods make a large-scale initiative to replace energy-inefficient ULT freezers logistically possible, reduce carbon footprint, and demonstrate an attractive return on investment while proactively protecting valuable research materials.

Exploring Important Attributes, the Potential Use Cases and Feasibility of Introduction of Measles and Rubella Microarray Patches (MR-MAPs): Insights from Nine Countries.

Background: Microarray patches (MAPs) are innovative, needle-free vaccine delivery systems, suitable for administration by minimally trained health care workers or trained community health workers. Their introduction may transform immunization programmes, particularly for vaccines where high coverage is required for population immunity, such as measles, and where vaccine delivery is challenging, such as in low- and middle-income countries. Recognizing the need to understand how best to tailor these products to reflect country priorities, workshops on measles and rubella MAPs (MR-MAPs) were conducted in multiple regions to collect insights on needs and preferences from relevant stakeholders at country level. Methods: The CAPACITI Innovation Framework was used to structure stakeholder discussions in nine countries in the period from August 2022 to July 2023. The discussions, building on the findings from a situation analysis on the barriers related to measles and rubella vaccine delivery, followed the four-step process outlined in the framework. Results: Key barriers hindering delivery of measles and rubella vaccines across the countries were in the categories of human resource management, service delivery, and demand generation. MR-MAP attributes that stakeholders believed would reduce or eliminate these barriers included ease of preparation and administration, improved thermostability, fewer (ancillary) components, and single-dose presentation. Some attributes such as the site of administration, wear time, and storage volume could exacerbate certain barriers. Based on an understanding of key barriers, product attributes, and underserved populations, stakeholders identified several potential use cases for MR-MAPs: (i) delivery at a fixed health post, (ii) delivery through outreach sessions conducted by health workers, and (iii) administration by community health workers. To enable robust national decision making about the introduction of MR-MAPs and successful implementation, global and national evidence on feasibility and acceptability of MR-MAPs should be generated. To prepare for the potential introduction of MR-MAPs, immunization programmes should evaluate their immunization policies based on their preferred use cases and modify them if needed, for example, to enable community health workers to administer vaccines, along with making programmatic adjustments to waste management and training. Conclusions: MR-MAPs have the potential to reduce key barriers to MR delivery. Yet, their future impact depends on the ability of global stakeholders to steer the development of MR-MAPs to be responsive to country needs and preferences. The generation of evidence to enable robust decision making, timely modification of vaccine policies, and addressing programmatic considerations will be key to successful uptake.

An integrated experimental-modeling approach to identify key processes for carbon mineralization in fractured mafic and ultramafic rocks.

Controlling atmospheric warming requires immediate reduction of carbon dioxide (CO2) emissions, as well as the active removal and sequestration of CO2 from current point sources. One promising proposed strategy to reduce atmospheric CO2 levels is geologic carbon sequestration (GCS), where CO2 is injected into the subsurface and reacts with the formation to precipitate carbonate minerals. Rapid mineralization has recently been reported for field tests in mafic and ultramafic rocks. However, unlike saline aquifers and depleted oil and gas reservoirs historically considered for GCS, these formations can have extremely low porosities and permeabilities, limiting storage volumes and reactive mineral surfaces to the preexisting fracture network. As a result, coupling between geochemical interactions and the fracture network evolution is a critical component of long-term, sustainable carbon storage. In this paper, we summarize recent advances in integrating experimental and modeling approaches to determine the first-order processes for carbon mineralization in a fractured mafic/ultramafic rock system. We observe the critical role of fracture aperture, flow, and surface characteristics in controlling the quantity, identity, and morphology of secondary precipitates and present where the influence of these factors can be reflected in newly developed thermo-hydro-mechanical-chemical models. Our findings provide a roadmap for future work on carbon mineralization, as we present the most important system components and key challenges that we are overcoming to enable GCS in mafic and ultramafic rocks.

ASSESSMENT OF THE POSSIBILITY OF USING A CO₂-BASED BUFFER WHEN ORGANIZING UNDERGROUND GAS STORAGE FACILITIES

The burial of CO2 in geological structures is considered to be current direction for reducing the negative impact of anthropogenic load in the form of greenhouse gases. Underground storage is also evaluated as a potential way to balance hydrogen production and consumption. The planned production of hydrogen in Russia by 2030 is expected to reach several billion m3 per year. To ensure the production and transportation of such volumes of gas, a hydrogen storage system is needed. Above-ground complexes and storage facilities in salt caverns cannot provide the required storage volumes. Aquifers are promising objects for long-term storage of both CO2 and hydrogen, including as part of a hydrogen-methane mixture.The work considers a hydrogen-methane mixture with a hydrogen concentration of 10–30 %, which is an economically justified value in most cases when producing this mixture.When storing hydrogen long-term in underground gas storage facilities, an important task is to assess hydrogen losses during storage.The authors, using linear hydrodynamic models taking into account phase transformations and hydrochemical effects, assessed the effectiveness of simultaneous CO2 burial and underground hydrogen storage through the injection of a hydrogen-methane mixture with a CO2 buffer rim.The models under consideration take into account: changes in the ionic composition of formation water, dissolution and precipitation of minerals.Analysis of the results showed that CO2 is not an effective buffer for the hydrogen-methane mixture even under the simplified conditions of the linear model. In this model, the region with a high hydrogen content disintegrates. At the same time, linear models do not take into account a number of negative factors that arise during the creation and operation of a full-fledged underground gas storage facility.

Modelling Water Availability in Livestock Ponds by Remote Sensing: Enhancing Management in Iberian Agrosilvopastoral Systems

Extensive livestock farming plays a crucial role in the economy of agrosilvopastoral systems of the southwestern Iberian Peninsula (known as dehesas and montados in Spanish and Portuguese, respectively) as well as providing essential ecosystem services. The existence of livestock in these areas heavily relies on the effective management of natural resources (annual pastures and water stored in ponds built ad hoc). The present work aims to assess the water availability in these ponds by developing equations to estimate the water volume based on the surface area, which can be quantified by means of remote sensing techniques. For this purpose, field surveys were carried out in September 2021, 2022 and 2023 at ponds located in representative farms, using unmanned aerial vehicles (UAVs) equipped with RGB sensors and survey-grade global navigation satellite systems and inertial measurement units (GNSS-IMU). These datasets were used to produce high-resolution 3D models by means of Structure-from-Motion and Multi-View Stereo photogrammetry, facilitating the estimation of the stored water volume within a Geographic Information System (GIS). The Volume–Area–Height relationships were calibrated to allow conversions between these parameters. Regression analyses were performed using the maximum volume and area data to derive mathematical models (power and quadratic functions) that resulted in significant statistical relationships (r2 > 0.90, p < 0.0001). The root mean square error (RMSE) varied from 1.59 to 17.06 m3 and 0.16 to 3.93 m3 for the power and quadratic function, respectively. Both obtained equations (i.e., power and quadratic general functions) were applied to the estimated water storage in similar water bodies using available aerial or satellite imagery for the period from 1984 to 2021.

Bathymetric Map Production of Therthar Depression Basin and Water Storage Volume Estimation

Water crisis, drought, and desertification are prominent environmental issues facing many countries and threaten their sustainable development. Therthar depression basin in Iraq was selected as a study area. A new approach was adapted in producing a bathymetric map by merging contours derived from both topographic maps and digital elevation models using ArcGIS applications. Water storage volumes were estimated from 2017 to the end of 2023 using the trapezoidal rule. The results demonstrate that the maximum water storage volume was 80% of the total storage capacity in 2019. In 2021, this percent began to decrease significantly as a result of climatic changes until reached a dead storage about 40% in 2023. Large surface area of Therthar depression leads to increased evaporation and infiltration rates. The water consumption exceeded the incoming water storage by 5.292 billion cubic meters (bcm) in May and 13.127 bcm in October, between 2017 and 2023. The comparison between the estimated and actual live storage volumes resulted a root mean square error of 0.534 m and a coefficient of determination (R2) equals 0.871. However, to award off flood risks in rainy years, the study proposes increasing Therthar depression design elevation to 67 m rather than 65 m in proportion to Therthar arranger gate level.

A framework for seasonal groundwater banking in agricultural regions: A case study

Groundwater banking has been used for demand-oriented management of groundwater resources in semi-arid and arid regions. This paper aims to propose a new framework for seasonal groundwater banking. In this framework, crop production functions are used to estimate users' bid packages representing the price of each unit volume of water in each auction period. The bid packages, along with users' water rights, are considered inputs of an optimization model, which maximizes the profit of users participating in the groundwater bank. The main outputs of the optimization model are the volumes of exchange and storage of water, as well as the water price in the auction periods. The efficiency of the proposed framework has been evaluated by applying it to the Nough region in the Rafsanjan Plain, central Iran. An existing plan for inter-basin water transfer to this region is also considered in the water banking framework. The results illustrate that the total annual profit of all users after the establishment of the bank compared to the status quo has increased up to 43.8 %. The profit of the water-recipient basin has also increased more than 4 times compared to the existing condition. In addition, water banking with a water transfer system increases the economic productivity of water and crop production by 37.32 % and 22.41 %, respectively.

Carbon stocks in mangrove ecosystems of Sri Lanka: Average contributions and determinants of sequestration potential

Mangroves are crucial in carbon sequestration despite covering only a small percentage of the Earth's surface. Latitudinal gradient primarily determines the distribution of climatic zones of distinct sunlight, temperature, and precipitation patterns, which influence the community structure of the mangrove ecosystem. The tropical climate of Sri Lanka contributes to the island's lush mangrove forests. The present study estimated that the average island's carbon sequestration capacity of Sri Lankan mangrove ecosystems is 524.25 t/ha representing a substantial volume of carbon storage that contributes to offset greenhouse effect due to increasing atmospheric CO2. Our results substantiated that rainfall positively influences total carbon sequestration capacity of mangrove ecosystems.It was also revealed that a positive relationship exists between vegetation structural complexity and sediment organic carbon, highlighting the influence of vegetation structure, that is primarily dependent on climatic conditions, on production of organic matter and sediment carbon sequestration. Globally, the carbon sink function of mangrove ecosystems is reported to be highest in the tropical areas and it declines towards sub-tropical higher latitudes while those in the southern hemisphere perform better carbon sinks than those in the northern hemisphere.The vertical distribution of total organic matter content in mangrove sediments was revealed to be in a descending order, manifesting the weak tidal removal of surface organic matter under the microtidal conditions in Sri Lankan marine waters, thus qualifying mangrove ecosystems in microtidal coasts as effective carbon sinks.

Towards standalone commercial buildings in the Mediterranean climate using a hybrid metal hydride and battery energy storage system

Given the critical role of hybrid energy storage systems in the building sector for enhancing renewable energy reliability and integration, this study examines the techno-economic feasibility of adopting a dual-level energy storage system for a PV-driven commercial building in the Mediterranean climate. The proposed system encompasses both hydrogen metal hydride and battery storage units. Aimed at off-grid electrification, the optimal component sizing of the hybrid system is identified by establishing a statistical optimization framework using the response surface methodology. Dynamic simulations of the hybrid system are performed through a TRNSYS model coupled with a numerical code that simulates the metal hydride system. Regarding optimal net-zero solutions, it is shown that the share of the direct PV electricity supply to end-use fluctuates within a limited range for all scenarios, namely between 57.7 and 60.5 %, while the share of each storage system varies distinctively in each solution. The results indicate a striking difference between scenarios in terms of economic aspects; differences of $ 19,791 and $ 32,621 are observed between the minimum and maximum values of the initial investment and life cycle cost, respectively. The levelized cost of electricity varies between 0.354 and 0.403 $/kWh, in which the case having the lowest payback period (10.8 years) demonstrates the lowest levelized cost of electricity too. Furthermore, an inverse relationship between the levelized cost of hydrogen and production rate is observed; the lowest levelized cost and the highest annual production are achieved in the scenario with the lowest BESS capacity and the highest electrolyzer power and hydrogen storage volume, which are equal to 5.77 $/kg and 304.7 kg H2/yr, respectively.

Structural strength and fatigue analyses of large-scale underwater compressed hydrogen energy storage accumulator

Underwater compressed hydrogen energy storage (UWCHES) is a potential solution for offshore energy storage. By taking advantage of the hydrostatic pressure of deep seawater, the compressed hydrogen can be isobarically stored in underwater artificial energy storage accumulators. The accumulator should withstand high pressure and large buoyancy and possess reliable anchoring to the seabed. In this study, the structural strength analysis and fatigue life of the large-scale accumulator is conducted employing the finite element method (FEM). The dimensionless stress prediction model and dimensionless fatigue life prediction model are developed through dimensional analysis and multivariate regression analysis. The performance of the accumulator with operating water depth of 100∼300 m, gas storage volume of 1081∼10128 m³, and concrete wall thickness of 0.1∼0.63 m is investigated. The results show that with an operating water depth of 100 m, gas storage capacity of 10,128 m3, and concrete wall thickness of 0.63 m, the maximum compressive stress is 1.43 MPa (yield strength is 60 MPa) and the maximum tensile stress of the accumulator is 2.55 MPa (yield strength is 6 MPa). The design fatigue life is 106 cycles which is larger than the expected service life of 104 cycles. Therefore, the accumulator structure meets the static strength and fatigue life. As the operating water depth increases with a consistent gas storage capacity, a transition in the stress state shifts from primarily tensile stress to predominantly compressive stress. The accuracy of the dimensionless stress prediction model and the dimensionless fatigue life prediction model were verified, with maximum deviations of 10.3 % and 13.7 %, respectively. Furthermore, the anchoring factor of safety of 1.12 is achieved.

A Study on the Construction and Evaluation of the Water Resource Reutilization System for Farmland Diversion and Drainage

Water is an essential resource for both rural and agricultural areas; it can be wisely distributed and used in the field to protect daily life, production, the natural environment, and the safety and stability of regional drainage and flood control systems. Our research selected a typical plains rural river network area with agriculture as the main industry to investigate the most effective method of farmland diversion and drainage. We comprehensively planned and transformed the water system flow, water conservation engineering, and the ecological environment in the irrigation area through the reutilization system. The reutilization system’s operation and scheduling design is implemented for four specific periods: the water replenishment cycle, agricultural irrigation, agricultural drainage and the rainy period of the flood season. The research period ranges from 2020 to 2023 after the completion of the system. We used monitoring, the recording of hydraulic equipment parameters and data collection to evaluate the balance of water supply and demand in the study area. At the same time, we have tracked and evaluated the four aspects of water quality enhancement, water conservation and flood control, and agricultural irrigation. The results show that the total agricultural water consumption decreased by 2.9%, and the amount of water saved increased by 9.6%. The current segment creates the rivers’ embankment standards. With a 92% irrigation guarantee rate, the current section forms and the embankment standards of the rivers satisfy the design storage volume and the flood level of one in twenty years. The water quality of all the rivers in the area has decreased by 5~10% compared to the average concentration prior to establishment. This study verifies the comprehensive effect and the suitability of the system by comparing the before and after effects, and provides a scientific basis for the method of efficient recycling and utilization of water resources in the rural plains river network area; we also propose the guidance of increasing the digital twin control and long-term operation mechanism to ensure the long-term stable operation of the technology.

Basin-scale study of CO2 storage in stacked sequence of geological formations

Commercial scale decarbonization through carbon capture and storage may likely involve many CO2 storage projects located in close proximity. The close proximity could raise concerns over caprock integrity associated with reservoir pressure buildup and interference among adjacent projects. Commercial-scale injection will also require large prospective CO2 storage resource and high injectivity in the targeted storage formations. To accommodate the need for both large resource and high injectivity, project operators could consider injecting CO2 into a stacked sequence of formations. This analysis investigates the benefits of injecting CO2 into a vertically stacked sequence of saline formations, over injecting the same amount of CO2 into a single saline formation, in addressing these challenges. Our analysis shows that injecting into the stacked sequence mitigates the extent of pressure buildup among the stacked formations, while still achieving the same or greater target CO2 storage volumes. Among cases modeled, the resulting pressure buildup front is most reduced when each storage site distributes injection volumes over several wells, each of which injects a portion of the total CO2 mass across the stacked sequence. This favorable case not only results in the smallest CO2 aerial footprint, but also shows the largest reduction in the pressure buildup at the top of perforation at the injection wells (upwards of approximately 46% compared to the single-formation storage), the result of which is crucial to maintain caprock integrity. This analysis provides insights into required decision-making when considering multi-project deployment in a shared basin.