Supply System Research Articles

Optimization of DC Energy Storage in Tokamak Poloidal Coils

Tokamaks are a very promising option to exploit nuclear fusion as a programmable and safe energy source. A very critical issue for the practical use of tokamaks consists of the power flow required to initiate and sustain the fusion process, in particular in the poloidal field coils. This flow can be managed by introducing a DC energy storage based on supercapacitors. Because such storage may be the most expensive and largest part of the poloidal power supply system, an excessive size would cancel its potential advantages. This paper presents innovative strategies to optimize the DC storage in poloidal power supply systems. The proposed solution involves the sharing of the DC storage between different coil circuits. The study is supported by novel analytical formulas and by a circuital model developed for this application. The obtained results show that this method and the related algorithms can noticeably reduce the overall size of the storage and the power exchange with the grid, providing a practical contribution toward the feasibility and the effectiveness of nuclear fusion systems.

Modeling Corrosion Product Deposition Processes in Pipelines of Heat Supply Systems

Modeling Corrosion Product Deposition Processes in Pipelines of Heat Supply Systems

Measures to increase the reliability and efficiency of water supply and wastewater disposal systems

The reliability of water supply and wastewater disposal systems has a significant impact on the environment: therefore, it is essential to implement new methods and approaches that reduce the risk of emergency situations. Based on the experience in automation, maintenance and modernization of wastewater disposal and water supply systems, the study suggests introducing additional programmable modules into automated control systems that provide control and regulation directly on the actuator. For this purpose, the study involves OWEN Logic programming environment, which manages pumping stations through programmable relays. The paper presents functional diagrams that have been introduced into standard macros to increase the reliability of pumping units. In addition, the paper demonstrates that the implementation of multi-level management facilitates the improvement of existing water supply and wastewater disposal systems, thereby increasing their functional capabilities and ensuring the efficient operation of technological equipment. The conducted analysis shows that the adoption of this method for managing technological processes will enhance the reliability and durability of the equipment, ensuring uninterrupted operation of pumping stations. With a change in the performance of water supply and wastewater disposal systems, the installed devices will allow for modernization with minimal economic costs, and reprogramming the operation of the low-level automation without affecting the performance of other levels.

Efficient utilization of enriched oxygen gas in residential PEMFC-CHP system with hydrogen energy storage

The oxygen byproduct generated from water electrolysis can be utilized on-site in residential combined heat and power (CHP) systems to enhance economic efficiency. This study explores solutions for optimizing the use of enriched oxygen gas (EOG) and determining the ideal oxygen fraction to maximize economic viability. A novel EOG supply system is designed to regulate oxygen fraction, oxygen excess ratio (OER), and humidity. A dynamic model of a PEMFC integrated with the EOG supply system is developed using MATLAB/Simulink® software and partially validated. The dual effects of EOG on system efficiency and remaining useful lifetime (RUL) are analyzed using a comprehensive economic optimization algorithm, leading to the identification of optimal oxygen fractions for various hydrogen production modes. Additionally, a feedforward static decoupling controller is designed to independently control the OER and oxygen fraction. The results indicate that, under rated conditions (10 kW), system power increased by 15 %, along with a 10 % improvement in system efficiency, from 48 % to 58 %. In conclusion, the efficient use of enriched oxygen gas demonstrates significant economic feasibility and practical viability, making it highly suitable for distributed power generation applications.

Southern Bug River: water security and climate changes perspectives for post-war city of Mykolaiv, Ukraine

This article focuses on water security in Mykolaiv, a city of 0.5 million inhabitants in southern Ukraine, in the situation of scarcity of usable water resources caused by climate change and military operations. This problem arose after the Dnipro-Mykolaiv water pipeline was destroyed in April 2022 as a result of military operations and the supply of drinking water to the city was cut off. To ensure that the city’s population has constant access to sufficient water of acceptable quality, a search for alternative water sources and a climate risk assessment were carried out for the new municipal water supply system from the Southern Bug River. The possible change in flow and its intra-annual distribution under the influence of climate change was modeled using the WaterGAP2 hydrological model and climate projections under the SSP1-2.6 and SSP5-P8.5 scenarios. It was found that under the SSP1-2.6 scenario, the reduction in river flow will be insignificant (up to a maximum of 14% in the far future) and there will be no restrictions on the city’s water supply from this section of the river in the near (2021-2050) and far (2051-2080) period. The maximum water withdrawal for municipal water supply and the minimum environmental flow will reach their maximum value only in August (56% of the projected flow), which is not critical. Under the SSP5-8.5 scenario, in the long-term perspective of 2051-2080, the largest decrease in runoff will occur from May to October, and the water withdrawal will increase to 40-79% of the projected flow. The use of the research results not only in water management, but also in municipal administration, and their dissemination in territorial communities will contribute to the successful adaptation of socio-economic and environmental processes in the region and can bring successful benefits not only to the economy, but also to communities.

Research on the monitoring system for induced voltage and ground current of 27.5 kV cable sheath in railways

PurposeThe purpose of this study is to address the deficiency in safety monitoring technology for 27.5 kV high-voltage cables within the railway traction power supply by analyzing the grounding methods employed in high-speed railways and developing an effective monitoring solution.Design/methodology/approachThrough establishing a mathematical model of induced potential in the cable sheath and analyzing its influencing factors, the principle of grounding current monitoring is proposed. Furthermore, the accuracy of data collection and alarm function of the monitoring equipment were verified through laboratory simulation experiments. Finally, through practical application in the traction substation of the railway bureau on site, a large amount of data were collected to verify the stability and reliability of the monitoring system in actual environments.FindingsThe experimental results show that the designed monitoring system can effectively monitor the grounding current of high-voltage cables and respond promptly to changes in cable insulation status. The system performs excellently in terms of data collection accuracy, real-time performance and reliability of alarm functions. In addition, the on-site trial results further confirm the accuracy and reliability of the monitoring system in practical applications, providing strong technical support for the safe operation of high-speed railway traction power supply systems.Originality/valueThis study innovatively develops a 27.5kV high-voltage cable grounding current monitoring system, which provides a new technical means for evaluating the insulation status of cables by accurately measuring the grounding current. The design, experimental verification and application of this system in high-speed railway traction power supply systems have demonstrated significant academic value and practical significance, contributing innovative solutions to the field of railway power supply safety monitoring.

Observer-based decoupling control of air flow and pressure in fuel cell systems

This paper investigates the control of the air supply system for marine proton exchange membrane fuel cells. A mathematical model of the air supply system is established, and a sliding mode diagonal decoupling controller based on a state observer is proposed. The control effectiveness is validated through experiments and simulations. A decoupling control strategy for the air supply system of marine fuel cells is presented. First, the load input current of the fuel cell system is selected according to the load characteristics of the target vessel, ensuring that the load current meets the power level of the fuel cell system model. Second, the impact of the cathode pressure on the fuel cell system is analyzed. An observer-based measurement method is proposed to address the measurement issue of cathode pressure. On this basis, a decoupling control strategy combining a diagonal decoupling matrix and sliding mode variable structure control theory is proposed. Finally, the effectiveness of the decoupling controller is validated through Matlab/Simulink. The results show the proposed decoupling controller exhibits superior performance to existing controllers with environmental disturbances, continuous time-varying loads, and step loads. The maximum relative error is 2.95%, the average relative error is 0.022%, and the longest adjustment time is 0.5 s. These results indicate that the control performance of the proposed decoupling controller is superior to that of diagonal PI controllers and sliding mode controllers, thereby validating the superiority of the sliding mode decoupling controller. This article provides a useful method for the development and application of control technology for the air supply system of marine fuel cells.

Optimization Analysis of Water Supply Mode for Fire Protection System of Super High Rise Building

Abstract In order to improve the applicability and reliability of the fire water supply capacity of super high-rise buildings, the fluid analysis software Flomaster was used for simulation. Through the existing pumps, valves, pipelines, pressure reducing valves and newly developed fire hydrants and other components, the fire water supply system of super high-rise buildings is modeled. The pressure distribution of the system pipe network under a given fire water supply mode is studied. The research shows that the simulation can analyze whether there is excessive pressure in the fire hydrant system under different flow conditions in the actual fire extinguishing process. This paper simulates the actual fire extinguishing process of the fire hydrant system through a specific engineering case. The pressure distribution and flow distribution under different flow conditions are obtained. The excessive pressure position of the fire pipe network system under the given fire pump model is obtained. It provides a method for guiding the selection of fire pump and the design of fire hydrant system pipe network. It has certain guiding significance for the subsequent optimization of the design scheme of the fire water supply network and the prediction of the performance of the R&D equipment.

How blast rate variation affects dynamic in-furnace behaviours and energy consumption of an industrial-scale blast furnace: A transient-state CFD study

Blast rate is a key operating parameter affecting the stability and energy consumption of ironmaking blast furnaces (BFs). Understanding the transient in-furnace behaviours resulting from blast rate variations is crucial for optimising BF operations and enhancing energy efficiency in the steel industry. The unplanned change in blast rate may occur sometimes, for example, due to the mechanical failures of blast supply system. However, the time-dependent evolution of in-furnace phenomena due to blast rate variations remains poorly understood. This work employs a transient BF model to numerically investigate the dynamic in-furnace behaviours following blast rate changes and explores potential countermeasures, providing valuable insights for BF operators to maintain furnace stability and performance under varying conditions. First, the impact of blast rate changes on in-furnace phenomena and key performance indicators are studied. The results show that when the bosh gas index ψ decreases by 7 m/min, the top gas temperature decreases by ∼67 K and the gas utilisation efficiency increases by 1.8 % within 20 h. If ψ increases by 3 m/min, the top gas temperature increases by 23 K, but the top gas utilisation efficiency decreases by 0.7 % in 20 h. Then, it is found that it takes nearly 20 h to recover the in-furnace phenomena after the blast rate is recovered from shortage and if blast rate is insufficient, increasing oxygen enrichment ratio from 1.5 % to 5 % improves the raceway temperature by 170 K in 40 h.

An universal energy-matching design and regulation method for combined cooling, heating, and power (CCHP) systems in different scenarios

In this study, the impact of the coupling matching mechanism between the systems and the users on the energy-saving characteristics of the systems was analyzed based on a universal representation and computation method to identify the energy saving potential of the systems. The physical model was detailed derived for the relationship between the load supply and user demands under different capacity design modes and operation strategies to construct a universal coupling matching diagram, and the impact of the coupling matching parameters (operational energy efficiency, load matching degree, etc) on system integration and operation in different energy use scenarios was quantitative analyzed to illustrate the inherent mechanism of energy saving characteristics. In addition, the coupling mechanism between the systems and the users from a global perspective was reconstructed, and a coupling method of capacity design factor and dual source regulation was proposed to realize the collaborative integration of centralized energy supply systems, combined cooling, heating, and power systems and load demands, as well as the active regulation of the internal cascade utilization of the systems, so as to improve the energy saving potential of the systems under all operating conditions. Finally, a case analysis and method verification were conducted using typical summer days at Kunming hotel as an example. The results show that the coupling matching relationship is the internal mechanism that affects the energy saving of the systems, and the average energy saving rate of the whole day can be increased by 7.45% through collaborative integration and active regulation.

Frost-resistant embankments with a novel ground source heat pump system

This study introduces a novel artificial heating technique aimed at addressing frost heave issues in embankments on frozen ground, offering a sustainable solution. Initial evaluations assessed various heating systems, including boilers, heat pumps, solar heaters, and electric heaters, focusing on their thermal performance and applicability. The study subsequently designed and implemented a direct-expansion ground source heat pump (DX-GSHP) system as the primary heat source for embankment warming. Rigorous testing confirmed the DX-GSHP system's ability to maintain a heat-supply temperature above 40 °C and a heat-absorption temperature below −3.5 °C, effectively extracting geothermal energy for transfer to the topsoil layers. With a demonstrated coefficient of performance (COP) of 3.49, the DX-GSHP system not only proves its energy efficiency but also suggests a potential role in reducing the strain on electricity supply systems. Installation of DX-GSHPs, with heating capacities ranging from 1.0–2.0 kW and spaced at intervals of 2.0–4.0 m, provides a rapid thermal response to frost heave in single-track railway embankments, thereby potentially mitigating frost-induced damage in cold climate regions.

Numerical simulation of miniature high-speed aviation fuel pump using immersed solid method

Abstract Aviation fuel pumps are developing toward lightweight design and high rotational speeds at the same time that vehicles, such as missiles and unmanned aerial vehicles (UAVs), gradually get smaller. To investigate the internal flow field characteristics of a miniature aviation gear pump under conditions of high rotational speed, three-dimensional numerical simulations are conducted using computational fluid dynamics (CFD) software ANSYS CFX. The simulations use the immersed-solid method and employ the SST k-ω turbulence model. The findings reveal that under identical conditions, augmenting the tooth width by 1mm leads to a notable 27.32% increase in the average outlet flow rate and a corresponding enhancement of 7.22% in maximum efficiency. Furthermore, a 2mm increment in tooth width results in a substantial surge of 62.74% in the average outlet flow rate and a significant enhancement of 14.61% in maximum efficiency. Nevertheless, concurrently, the augmentation of tooth width corresponds with a gradual rise in trapped oil pressure and significant deterioration of the internal flow field. The study findings offer valuable insights into the integrated design of the oil supply system and engine components of aerospace engines.

Circular Economy in Heat Supply Systems for Buildings: An Overview of the End of Life of System Components and Existing Evaluation Systems and Products

Abstract In order to achieve climate protection targets, many heating systems must be converted to renewable energies and more efficient systems. Most of residential buildings in Germany are heated with natural gas (50 %), 25 % with an oil. Around 45 % of the heating systems are older than 15 years, 20,5 % are even older than 25 years. Therefore, a high replacement rate is to be expected in the next few years. In the context of circular economy, the accumulating materials should remain in the material cycle. Some materials, such as metals, can be recycled easily. However, building services engineering, in particular heat supply, has become increasingly complex. This paper focuses on the state of the circular economy of heat supply systems for buildings. Firstly, a detailed examination of products utilized in heat supply systems is undertaken. Secondly, an assessment of the end-of-life scenarios for these components was conducted, considering disposal routes and recycling rates. Lastly, an evaluation of assessment systems fostering a circular economy regarding heat supply systems is performed. The aim of the work is to provide an overview of the state of the art with regard to circular economy in heat supply and thereby draw conclusions as to where potentials and obstacles exist.

High-frequency Resonance Suppression of Railway Traction Power Supply System Based on the Combination of Single-tuned and C-type Filters

Background: Railroad transportation in the actual operation process, there are also many dangerous accidents caused by resonance, which greatly affect the safety of railroad transportation. A comprehensive examination of the operational dynamics within the power branch of a traction substation is imperative for sustaining system equilibrium. Discrepancies between these facets pose a potential threat to the safety of railway transport. Thus, a meticulous analysis of highfrequency resonance characteristics and the formulation of effective suppression techniques become paramount. Objective: Harmonics from grid-side locomotive traction braking are scrutinized under different operational scenarios and different train runs. The aim is to develop an effective harmonic management strategy to normalize the THD and thus maintain the traction power supply system to become more stable. Methods: This study investigates the high-frequency harmonic resonance characteristics using a control variable approach. Harmonics and negative sequences generated during locomotive traction braking under different operating conditions are investigated by means of extensive analysis. These challenges require the implementation of a harmonic management method. This method uses a combination of two monotonic filters and a C filter in parallel. This method applies to different operating conditions and can dynamically adapt harmonics to changes in the number of trains, which is related to the actual dynamics of the traction power system closely. Results: A comparative evaluation of seven operating conditions shows that the filter in this patent exceeds the efficiency of existing methods. The filter reduces the fluctuations during spectral changes, and the voltage distortion rate decreases from the previous 2.33% to 0.55%, making it more adaptable and promising effective harmonic management in high voltage and high current situations. Conclusion: Through multiple simulation tests, a synergistic configuration involving the C-type filter and two single-tuned parallel connections under regenerative braking conditions emerges. This refined, patented filter design not only mitigates the impact of negative sequence during the filtration process but also substantially diminishes high harmonics and THD.

Toward sustainable energy switch in built environment: learning from ongoing experiences

Abstract The contribution addresses the topic of the ecological transition of energy production and supply systems of built environment, mean as an evolution towards sustainable forms of reorganization of human communities. To this end, focuses its attention on the most recent application experiences, to compare what has been outlined at the political and financial level, with the output generated by the concrete interventions, by the energy, environmental and social point of view. A broad and varied picture emerges, in which the actions ranges from the energy solarization of individual or complex of buildings, to the solar use of large portions of territory. The analysis and classification of each initiative it made possible to understand which are the most widespread solutions and which requires greater support to be accepted at the local community level. It also consented to understand the need to integrate each initiative within a design process oriented towards preserving the quality of urban and rural landscape. This innovative approach, based on a bottom-up operational models founded on a public-private partnerships, a multidisciplinary of actors and an active participation of citizens, constitutes the next objective assumed by research work, oriented to define an operative design based procedure, able to support public and private actors in the choices formulation.

Research on a novel method of air distribution to create a uniform indoor environment in a long and narrow building

Because people work a long time in buildings, good indoor thermal environments and air distributions have attracted increased amounts of attention. To improve the indoor thermal environment and air quality, an effective ventilation strategy must be used. In the air conditioning of a building, the air distribution has been identified as a significant factor that affects the indoor thermal environment. A novel method for air distribution was presented to create a uniform indoor environment along the room length direction. In this study, numerical simulations were carried out to analyse the airflow pattern and performance of the sidewall air supply (SAS) and the sidewall air supply with deflector (SASD). Orthogonal experiments were conducted to study the airflow distribution law of the deflector. The ventilation performance of the two air supply modes was evaluated by air velocity distribution, temperature distribution, horizontal temperature difference, age of air, and other evaluation indicators. The results indicate that the horizontal air temperature differences in the SASD at three heights are 46.05%, 16.44%, and 26.51% lower than those in the SAS, which has a better energy-saving effect. Moreover, the indoor air distribution performance was obtained under three influencing factors: the gap width from the deflector to the ceiling, the horizontal position, and the length of the deflector. A better deflector optimization scheme was obtained. Experimental research was carried out to verify the indoor air distribution of the SASD. This research can provide a reference for the innovative design of indoor air supply systems

Construction of Hydrogen Fuel Backup Power Supply System based on Data Communication Technology

The study presents a comprehensive examination of integrating hydrogen gas cells into backup electricity systems, strengthened by superior records verbal exchange technologies. This modern approach targets to address the growing interest for reliable and sustainable strength sources within the context of developing issues about environmental sustainability and the restrictions of traditional fossil gasoline-based totally power structures. On the middle of this studies is the improvement of a hydrogen gasoline cellular-based totally backup strength device. Hydrogen fuel cells, regarded for his or her excessive strength performance and low environmental impact, offer a promising opportunity to standard energy resources. The device leverages the inherent advantages of hydrogen as a clean strength carrier, making sure reduced carbon emissions and greater energy safety. A giant component of this have a look at is the combination of contemporary data communication generation. This integration facilitates real-time tracking and control of the electricity gadget, ensuring surest performance and reliability. Advanced statistics analytics are hired to are expecting energy demand, reveal gas cell health, and optimize the machine’s operation. This approach no longer handiest complements the performance of the energy supply but also ensures a unbroken transition between the number one energy supply and the backup device at some point of outages. The studies methodology encompasses a blend of theoretical analysis and realistic experimentation. Simulation models are used to test the device’s efficacy underneath numerous scenarios, followed via a prototype implementation to validate the theoretical findings. The look at also explores the monetary viability and scalability of the proposed machine, making it relevant for big adoption.

Curcumin Inhibits Vasculogenic Mimicry via Regulating ETS-1 in Renal Cell Carcinoma.

Metastatic renal cell carcinoma (RCC) poses a huge challenge once it has become resistant to targeted therapy. Vasculogenic mimicry (VM) is a novel blood supply system formed by tumor cells that can circumvent molecular targeted therapies. As one of the herbal remedies, curcumin has been demonstrated to play antineoplastic effects in many different types of human cancers; however, its function and mechanism of targeting VM in RCC remains unknown. Here, in the work, we explored the role of curcumin and its molecular mechanism in the regulation of VM formation in RCC. RNA-sequencing analysis, immunoblotting, and immunohistochemistry were used to detect E Twenty Six-1(ETS-1), vascular endothelial Cadherin (VE-Cadherin), and matrix metallopeptidase 9 (MMP9) expressions in RCC cells and tissues. RNA sequencing was used to screen the differential expressed genes. Plasmid transfections were used to transiently knock down or overexpress ETS-1. VM formation was determined by tube formation assay and animal experiments. CD31-PAS double staining was used to label the VM channels in patients and xenograft samples. Our results demonstrated that VM was positively correlated with RCC grades and stages using clinical patient samples. Curcumin inhibited VM formation in dose and time-dependent manner in vitro. Using RNA-sequencing analysis, we discovered ETS-1 as a potential transcriptional factor regulating VM formation. Knocking down or overexpression of ETS-1 decreased or increased the VM formation, respectively and regulated the expression of VE-Cadherin and MMP9. Curcumin could inhibit VM formation by suppressing ETS-1, VE-Cadherin, and MMP9 expression both in vitro and in vivo. Our finding might indicate that curcumin could inhibit VM by regulating ETS-1, VE-Cadherin, and MMP9 expression in RCC cell lines. Curcumin could be considered as a potential anti-cancer compound by inhibiting VM in RCC progression.

Groundwater in Katowice - center of a large urban and deep coal mining area in Poland

The paper presents the groundwater resources of Katowice and the results of studies conducted to identify prospective areas in aquifers with sufficient water resources for the location of public water intakes. The city of Katowice is the capital of Upper Silesia, the largest urban-industrial area in Poland, the region with a highly developed hard coal mining and many other different industries covering almost the entire scope of the economy. Due to long term drainage of mines causing the depletion and deterioration of groundwater and surface water resources, the main municipal water intakes have been located outside Katowice. Most of the pumped mine water is discharged into surface waters, causing significant salinity of water and disallow its use for municipal or industrial purposes in Katowice. The water collection and supply system is very extensive and covers a significant part of the Silesian agglomeration which is why Katowice is supplied with water from surface water intakes located outside the city. According to older published materials, such as the Hydrogeological map of Poland, there were no aquifers in the city that could have been used to supply the city with drinking water, however recent studies have shown that groundwater in the Quaternary aquifers in the western part of the city can be used to supply the city with public water. Less productive, Quaternary aquifers in north-eastern parts of the city may constitute the basis for drinking water supply in emergency situations, when surface intakes cannot be used, such as toxic, radiological or viral contamination or damage to the water supply network eg. as a result of an earthquake or warfare.

Groundwater resilience, security, and safety in the four largest cities in Denmark

Denmark's complete reliance on groundwater for water supply presents a unique case study in management of natural resources, urban planning, and water resilience in the face of climate change. This paper examines the groundwater management strategies in Denmark in general, focusing on Denmark's four largest cities—Copenhagen, Aarhus, Odense, and Aalborg— each facing distinct challenges due to their demographic, geographical, hydrogeological, and economic characteristics. Through analysis of these cities' approaches to groundwater management, this research contributes to the global discourse on sustainable urban water supply systems. As coastal groundwater cities (CGC), these urban areas must navigate the complexities of sustaining growing populations, mitigating climate change impacts, and coastal processes while ensuring the long-term viability of their groundwater resources. Copenhagen and Aalborg, built atop semi-confined fractured and locally karstic carbonate rocks, highlights the specific challenges associated with karstic groundwater systems, while, Aarhus, and Odense built on glaciofluvial aquifers faces different issues. The different groundwater challenges in these cities underscores the importance of integrating urban development with water resource management and environmental sustainability, offering valuable insights and lessons learned for other regions facing similar challenges. This study, thus not only sheds light on Denmark's groundwater management practices, but also emphasizes the need for innovative solutions to ensure the resilience of urban water supply systems in a changing climate and increasing pressures of emerging organic contaminants and elevated concentrations of geogenic elements induced by water abstraction and fluctuating water tables. Advanced Danish monitoring and modelling tools applied to support decision-making and innovation within the water sector are continuously developed and improved to support resilient and sustainable management of the available water resources.