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1
Huber, David, Viktoria Illyés, Veronika Turewicz, Gregor Götzl, Andreas Hammer, and Karl Ponweiser. "Novel District Heating Systems: Methods and Simulation Results." Energies 14, no. 15 (July 23, 2021): 4450. http://dx.doi.org/10.3390/en14154450.
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Fifth-generation district heating and cooling (5th DHC) systems offer promising approaches to decarbonizing space heating, cooling and domestic hot water supply. By using these systems, clustered buildings combined with industrial waste heat can achieve a net-zero energy balance on a variety of time scales. Thanks to the low exergy approach, these systems are highly efficient. As part of the Smart Anergy Quarter Baden (SANBA) project, the thermal energy grid simulation tool TEGSim has been further developed and used to design an ultra-low-temperature district heating (ULTDH) network with hydraulic and thermal components fitted to the specific regional characteristics of the investigated case. Borehole thermal energy storage (BTES) used as seasonal storage ensures long-term feasibility. The annual discrepancy of input of thermal energy provided by space cooling and output of energy demanded by space heating and domestic hot water is supplied by an external low-grade industrial waste heat source. This paper presents the functionality of the simulation and shows how to interpret the findings concerning the design of all components and their interplay, energy consumption and efficiencies.
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Chen, Zhi Cheng, Lu Yao, and Jian Jun Yang. "A Research Review of Project Risk Assessment Methods." Applied Mechanics and Materials 496-500 (January 2014): 2857–62. http://dx.doi.org/10.4028/www.scientific.net/amm.496-500.2857.
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Based on the domestic and overseas researches of project risk assessment methods, this paper classifies project risk assessment methods into subjective judgment methods, evidence and deduction methods, system simulation methods and other methods. After exploring their definitions, advantages and disadvantages, this paper points out that subjective judgment and empirical analogy become two mainstream risk assessment methods. In the end, this paper claims that a risk assessment method does not need any unfathomable theory for its obvious engineering characteristics, but focuses on operability and applicability.
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Zharov, M. V. "Research of prospects of application of software environments of simulation modeling in the development and optimization of mechanical engineering production." Вестник Пермского университета. Математика. Механика. Информатика, no. 3(54) (2021): 58–67. http://dx.doi.org/10.17072/1993-0550-2021-3-58-67.
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The article presents the results of the market research of applied simulation programs from the point of view of the possibility and expediency of using the latter in the development or optimization of technological processes at domestic machine-building enterprises. The features of technological processes of mechanical engineering and aircraft construction at domestic enterprises are analyzed. The features of the production of metal-intensive products and semi-finished products are studied from the point of view of the feasibility of simulation modeling of these processes. The expediency of conducting simulation modeling of machine-building industries is determined, which provides adequate analysis results at minimal cost compared to other modeling methods. The main criteria for selecting a specific simulation software are defined.
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Aydin, Nesli, Emrah Bektas, and Suna Ozden Celik. "ANALYSIS OF MICROFIBRES RELEASED FROM DOMESTIC LAUNDRY WITH EXPERIMENTAL METHODS AND SIMULATION MODELS." Environmental Engineering and Management Journal 21, no. 9 (2022): 1451–60. http://dx.doi.org/10.30638/eemj.2022.128.
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Ahn, Yonghan, Hanbyeol Jang, and Junghyon Mun. "Comparison of Building Simulation Methods for Modeling Apartment Balconies." Energies 14, no. 13 (July 1, 2021): 3955. http://dx.doi.org/10.3390/en14133955.
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The purpose of this study is to compare the load calculation results by a model using the air changes per hour (ACH) method and a model using an airflow network (AFN) and to ascertain what causes the difference between the two models. In the basic case study, the difference in the heat transfer distribution of the model in the interior space was investigated. The most significant difference between the two models is the heat transfer that results from infiltration. Parameter analysis was performed to investigate the relationship between the difference and the environmental variables. The result shows that the greater the difference is between the air temperature inside the balcony and the outdoor air temperature, and the greater the air flows from the balcony to the residential area, and the greater the heating and cooling load difference occurs. The analysis using the actual weather files of five domestic cities in South Korea rather than a virtual case shows that the differences are not so obvious when the wind blows at a constant speed throughout the year, but are dominant when the wind does not blow during the night and is stronger alongside the occurrence of sunlight during the day.
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Carretero, C., O. Lucia, J. Acero, R. Alonso, and J. M. Burdio. "Frequency-dependent modelling of domestic induction heating systems using numerical methods for accurate time-domain simulation." IET Power Electronics 5, no. 8 (2012): 1291. http://dx.doi.org/10.1049/iet-pel.2012.0113.
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Kang, Seokho, Junhee Kim, Yeongsu Kim, Yushin Ha, and Seungmin Woo. "RETRACTED ARTICLE: Simulation Study of Dynamic Characteristics of Hot Pepper Harvester." Journal of Biosystems Engineering 45, no. 4 (December 2020): 333–40. http://dx.doi.org/10.1007/s42853-020-00074-7.
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Abstract Purpose Determining the safety conditions of a hot pepper harvester to mechanize harvesting. Methods The dynamic characteristics of a hot pepper harvester were analyzed with the dynamic simulation program RecurDyn. Results The pepper harvester can climb a maximal slope of 25° under full loading conditions; the maximal allowable height of an obstacle over which the harvester can drive is 450 mm; the minimal rotation radius during a spin turn is 870 mm. Conclusions Considering its dynamic characteristics, the harvester can be applied on over 95% of domestic upland fields. The safety accident rate can be decreased with the use of the spin turn method. In conclusion, the dynamic characteristics are sufficiently safe for the domestic upland fields.
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Yang, Jian Jiang, Rui Wang, and Bo Zhou. "A Review on Numerical Simulation of Pile Caps in Large-Scale Structures." Applied Mechanics and Materials 94-96 (September 2011): 131–35. http://dx.doi.org/10.4028/www.scientific.net/amm.94-96.131.
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Cap plays a transitional role in the structure. It is an important part to ensure the effective pass of load between the upper structure and the foundation. In the bridge, water tank, ocean platforms, oil tank and other large-scale structures, the force mechanism and force mode about cap are more and more valued by researchers. The research method about large cap structure mainly includes theoretical research, experimental research, numerical simulation and other aspects. This article summarizes the domestic research status, reviews and compares the caps’ numerical simulation methods and analyzes the advantages and disadvantages of different models. Finally, some problems are proposed for further research, which can provide references for engineering design and study.
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Li, Kebai, and Zhilei Ding. "Dynamic Modeling and Simulation of Urban Domestic Water Supply Inputs Based on VES Production Function." Mathematics 10, no. 1 (December 27, 2021): 89. http://dx.doi.org/10.3390/math10010089.
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The Gompertz growth curve is used to describe the urban water population, the linear function is used to represent the per capita disposable income, and the domestic water demand is described combined with the factors of population, income, and the water-saving consciousness. The VES production function is used to describe the production function of the domestic water supply. Combined with system dynamics, the supply and demand management model of urban domestic water in Jiangsu province, China, is developed. The process of water supply investment and labor input in the urban domestic water system is studied with two depreciation methods: the straight-line depreciation method and the sum of years digits method. In the case that the water consumption population is expected to decline, four water demand scenarios composed of different per capita disposable income and the growth rate of water-saving consciousness are investigated. Investment and labor input are taken as control variables to conduct water supply and demand simulations for the four scenarios. The results show that the control schemes in all four scenarios reach a balance between water supply and demand. Moreover, the investment of the sum of years digits method is larger than that of the straight-line depreciation method in 2005–2019 but less than that of the straight-line depreciation method in 2020–2034. The sum of years digits method has the characteristics of more depreciation in the early stage and less depreciation in the later stage, which is conducive to timely compensation for the large loss of fixed assets in the early stage.
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Gao, Fei, Qiong Wu, Jiang Ben Min, and Mei Ting Jiang. "Develop of Downhole Simulation Tests Device near the Pump Suction for Corrosion." Advanced Materials Research 807-809 (September 2013): 2514–18. http://dx.doi.org/10.4028/www.scientific.net/amr.807-809.2514.
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At present, the corrosion of the casing near downhole pump suction port is common in some domestic oilfield. In order to study the corrosion mechanism, we design and manufacture a dynamic simulation test device for the corrosion of the casing near downhole pump suction port.The device adopts the single plunger pump and tube and casing string in line with site structure to simulate the intermittent production mode of pump as well as the fluids flow state near the pump inlet adequately, and achieves the corrosion velocity measurement and the research of corrosion behavior under different temperature, CO2 partial pressure, and velocity. The preliminary experimental results show that the test device has the advantages of reasonable structure, strong simulation and practicality; it provides new methods of testing for the related experimental study under the condition of different corrosion mechanism and has good application prospects.
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Ward, S., F. A. Memon, and D. Butler. "Rainwater harvesting: model-based design evaluation." Water Science and Technology 61, no. 1 (January 1, 2010): 85–96. http://dx.doi.org/10.2166/wst.2010.783.
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The rate of uptake of rainwater harvesting (RWH) in the UK has been slow to date, but is expected to gain momentum in the near future. The designs of two different new-build rainwater harvesting systems, based on simple methods, are evaluated using three different design methods, including a continuous simulation modelling approach. The RWH systems are shown to fulfill 36% and 46% of WC demand. Financial analyses reveal that RWH systems within large commercial buildings maybe more financially viable than smaller domestic systems. It is identified that design methods based on simple approaches generate tank sizes substantially larger than the continuous simulation. Comparison of the actual tank sizes and those calculated using continuous simulation established that the tanks installed are oversized for their associated demand level and catchment size. Oversizing tanks can lead to excessive system capital costs, which currently hinders the uptake of systems. Furthermore, it is demonstrated that the catchment area size is often overlooked when designing UK-based RWH systems. With respect to these findings, a recommendation for a transition from the use of simple tools to continuous simulation models is made.
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Zouloumis, Leonidas, Angelos Karanasos, Nikolaos Ploskas, and Giorgos Panaras. "Multicriteria Design and Operation Optimization of a Solar-Assisted Geothermal Heat Pump System." Energies 16, no. 3 (January 25, 2023): 1266. http://dx.doi.org/10.3390/en16031266.
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This work focuses on the determination of the design and operation parameters of a thermal system depending on the optimization objective set. Its main objective and contribution concern the proposal of a generalized methodological structure involving multiobjective optimization techniques aimed at providing a solution to a practical problem, such as the design and dimensioning of a solar thermal system. The analysis is based on system operation data provided by a dynamic simulation model, leading to the development of multiple surrogate models of the thermal system. The thermal system surrogate models correlate the desired optimization objectives with thermal system design and operation parameters while additional surrogate models of the Pareto frontiers are generated. The implementation of the methodology is demonstrated through the optimal design and operation parameter dimensioning of a solar-assisted geothermal heat pump that provides domestic hot water loads of an office building. Essentially, energy consumption is optimized for a desired domestic hot water thermal load coverage. Implementation of reverse-engineering methods allows the determination of the system parameters representing the optimized criteria.
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Kovrigin, Artur A., and Mikhail Yu Slesarev. "A change model of the hydraulic characteristics of the territory occupied by the landfill of solid industrial and domestic waste." Vestnik MGSU, no. 6 (June 2021): 770–80. http://dx.doi.org/10.22227/1997-0935.2021.6.770-780.
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Introduction. A landfill of solid industrial and domestic waste (LSIDW) is a source of negative impact on the environment. Although landfills have coverings, and they are equipped with engineering systems designated for the capturing and treatment of the biogas, LSIDW landfills still have a negative impact on subsurface and surface waters due to the spread of leachate. The purpose of this work is to obtain predictive data on changes in the hydrogeological characteristics of the territory of Salaryevo landfill, and to develop a simulation model to assess the application of technical solutions in the course of the landfill reclamation.
Materials and methods. Processing Modflow is the software designated for the 3D modeling of filtration and transportation of pollutants. An engineering report based on the engineering and environmental surveys, performed by JSC MosvodokanalNIIproekt in the Salaryevo landfill and its environs in 2017, served as the input data designated for a simulation model.
Results. Processing Modflow software allowed to consider three options of cutoff walls, tailored to this landfill. The installation of cutoff walls on the east and west sides of the landfill, to be performed with regard for the sorption function of the cutoff walls, is the most effective solution. The results have shown that the cutoff walls, installed to prevent the leachate from seeping, can potentially reduce the area, exposed to the impact, by 500 m.
Conclusions. It is recommended to install a cutoff wall in the west and a sorption curtain in the east in the course of recultivating Salaryevo landfill; this solution will ensure the containment of the leachate inside the landfill and prevent its spreading.
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Elhussieny, Amal, Salma O. M. Elshabrawy, Nora Mohamed, Irene S. Fahim, Lobna A. Said, and Ahmed G. Radwan. "Evaluation of Membranes’ Performance in Wastewater Treatment by WAVE Simulation." International Journal of Emerging Technology and Advanced Engineering 13, no. 1 (January 3, 2023): 63–72. http://dx.doi.org/10.46338/ijetae0123_08.
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- Dye is considered a carcinogenic matter. So, it is extremely important to treat the wastewater which contains the dye by detecting eco-friendly technologies to protect the environment from any negative impacts, the resources of natural water, and facing water shortage. The treatment of wastewater can be applied by using low-cost by-products from various sources such as domestic, industrial, and agricultural sectors. They enable the elimination of pollutants from wastewater and support the reduction, recovery, and reuse of waste. This study represents current membrane technologies for dye removal using the WAVE simulation software, provided by Dupont to study the performance, process parameters, and operating conditions. The WAVE simulation software explained also the benefits and drawbacks of various treatment methods. This research aims to investigate the physical properties and efficiency of the synthesized composite membranes and determine their feasibility for use in membrane filtration.
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Campisano, A., and C. Modica. "Regional scale analysis for the design of storage tanks for domestic rainwater harvesting systems." Water Science and Technology 66, no. 1 (July 1, 2012): 1–8. http://dx.doi.org/10.2166/wst.2012.171.
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A regional scale analysis for the design of storage tanks for domestic rain water harvesting systems is presented. The analysis is based on the daily water balance simulation of the storage tank by the yield-after-spillage algorithm as tank release rule. Water balances are applied to 17 rainfall gauging stations in Sicily (Italy). Compared with literature existing methods, a novel dimensionless parameter is proposed to better describe the intra-annual character of the rainfall patterns. As a result, easy-to-use regional regressive models to evaluate the water saving performance and the overflow discharges from the tank are provided along with a stepwise procedure for practical application. The regional models demonstrate good fits between model predictions and simulated values of both water savings and overflows from the tank.
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Mathur, Rajshree, and Meena Kumari Sharma. "Modeling and optimization of the anaerobic digestion system for domestic waste water treatment with the development of monitoring techniques." IOP Conference Series: Earth and Environmental Science 1084, no. 1 (October 1, 2022): 012046. http://dx.doi.org/10.1088/1755-1315/1084/1/012046.
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Abstract Water scarcity and wastewater management are two most serious environmental problems faced by developing countries like India. Recycling and reuse of the treated wastewater for non-potable purpose may significantly reduce the stress on fresh water requirement. Anaerobic digestion methods are used to treat wastewater discharge from various fields. Software tools provide an opportunity for engineers to create models which represent activities, resources, and the environment in powerful, affordable and user-friendly way. Modeling and simulation results serve as an important guideline in the optimization and process control for plant operators and other specialists in the field of engineering. Model-based development of software using tools such as Math Works Simulink has become common in the engineering. The Anaerobic Digestion Model (ADM1) from the International Water Association might be used for modeling and optimization of digestion operations. This research reveals the study of domestic wastewater treatment using ADM1. The process equations are solved using the input data, and output is generated. The results show that the proposed method is capable of predicting process parameters of excellent stream with high degree of accuracy (R2=0.945).
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Cuel, Maressa Fabiano, Wu Hong Kwong, Marcelo Zaiat, and Eugenio Foresti. "Solution of a heterogeneous modeling of a horizontal-flow anaerobic immobilized biomass (HAIB) reactor by the sequencing method." Canadian Journal of Civil Engineering 38, no. 4 (April 2011): 415–21. http://dx.doi.org/10.1139/l11-014.
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A modeling study was completed to develop a methodology that combines the sequencing and finite difference methods for the simulation of a heterogeneous model of a tubular reactor applied in the treatment of wastewater. The system included a liquid phase (convection–diffusion–transport) and a solid phase (diffusion reaction) that was obtained by completing a mass balance in the reactor and in the particle, respectively. The model was solved using a pilot-scale horizontal-flow anaerobic immobilized biomass (HAIB) reactor to treat domestic sewage, with the concentration results compared with the experimental data. A comparison of the behavior of the liquid phase concentration profile and the experimental results indicated that both the numerical methods offer a good description of the behavior of the concentration along the reactor. The advantage of the sequencing method over the finite difference method is that it is easier to apply and requires less computational time to model the dynamic simulation of outlet response of HAIB.
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Yang, Chao, Guangsheng Luo, Xigang Yuan, Jie Chen, Yangcheng Lu, Xiaojin Tang, and Aiwu Zeng. "Numerical simulation and experimental investigation of multiphase mass transfer process for industrial applications in China." Reviews in Chemical Engineering 36, no. 1 (December 18, 2019): 187–214. http://dx.doi.org/10.1515/revce-2017-0050.
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Abstract This paper presents a comprehensive review of the remarkable achievements by Chinese scientists and engineers who have contributed to the multiscale process design, with emphasis on the transport mechanisms in stirred reactors, extractors, and rectification columns. After a brief review of the classical theory of transport phenomena, this paper summarizes the domestic developments regarding the relevant experiments and numerical techniques for the interphase mass transfer on the drop/bubble scale and the micromixing in the single-phase or multiphase stirred tanks in China. To improve the design and scale-up of liquid-liquid extraction columns, new measurement techniques with the combination of both particle image velocimetry and computational fluid dynamics have been developed and advanced modeling methods have been used to determine the axial mixing and mass transfer performance in extraction columns. Detailed investigations on the mass transfer process in distillation columns are also summarized. The numerical and experimental approaches modeling transport phenomena at the vicinity of the vapor-liquid interface, the point efficiency for trays/packings regarding the mixing behavior of fluids, and the computational mass transfer approach for the simulation of distillation columns are thoroughly analyzed. Recent industrial applications of mathematical models, numerical simulation, and experimental methods for the design and analysis of multiphase stirred reactors/crystallizers, extractors, and distillation columns are seen to garnish economic benefits. The current problems and future prospects are pinpointed at last.
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Kolmogorcev, N. I., and T. N. Khatsevich. "Circuit designs for construction of pancratic telescopes." Interexpo GEO-Siberia 8, no. 1 (May 18, 2022): 49–59. http://dx.doi.org/10.33764/2618-981x-2022-8-1-49-59.
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The improvement of classical telescopes designed to observe distant objects is currently associated with the provision of operating modes with interchangeable magnification and the possibility of photo and video recording. The purpose of the paper is to propose circuit designs for optical systems of high-magnification pancratic telescopes and substantiate the possibility of their use in engineering. The paper is based on the engineering design of two variants of telescope optical systems with a magnification of 20 to 60 times, in the first of which the pancratic change of magnification is provided by the movements of the components in the ocular part, in the second - in the objective part. The characteristics of pancratic telescopes are considered. It was revealed that in modern models the pancratic change of magnifications is carried out in the ocular and objective parts of the system. Computer simulation methods were used to synthesize optical schemes in the paraxial approximation, followed by the implementation of systems with finite apertures and thicknesses. The developed systems can be used at domestic enterprises of optical instrumentation.
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Wang, Jun, and Zhi Wei Sun. "Application and Design of the New Steel Fiber RPC Column-Template without Demolition." Applied Mechanics and Materials 120 (October 2011): 288–91. http://dx.doi.org/10.4028/www.scientific.net/amm.120.288.
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Innovation of material and function represents the direction of contemporary architecture template development. Based on the study results of domestic and foreign building templates, a new type of template structure—Steel fiber RPC (reactive powder concrete) column-template without demolition is presented taking account of the characteristics of template materials and construction methods. Compared with the traditional template, the new one takes composite material and function innovation as a breakthrough. It improves efficiency of construction while the column-template forms the outer surface of the decorative grass-roots which expands the scale of the function of column template. This paper introduces the material selection and illustrates the calculation of the new template. Based on the existing design specification of template, new design recommendation of template thickness is proposed through theoretical analysis and simulation, which provides a theoretical basis of steel fiber RPC column template without demolition in engineering applications.
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Karande, Jalindar, and Sarang Joshi. "DEDA: An algorithm for early detection of topology attacks in the internet of things." International Journal of Electrical and Computer Engineering (IJECE) 11, no. 2 (April 1, 2021): 1761. http://dx.doi.org/10.11591/ijece.v11i2.pp1761-1770.
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The internet of things (IoT) is used in domestic, industrial as well as mission-critical systems including homes, transports, power plants, industrial manufacturing and health-care applications. Security of data generated by such systems and IoT systems itself is very critical in such applications. Early detection of any attack targeting IoT system is necessary to minimize the damage. This paper reviews security attack detection methods for IoT Infrastructure presented in the state-of-the-art. One of the major entry points for attacks in IoT system is topology exploitation. This paper proposes a distributed algorithm for early detection of such attacks with the help of predictive descriptor tables. This paper also presents feature selection from topology control packet fields. The performance of the proposed algorithm is evaluated using an extensive simulation carried out in OMNeT++. Performance parameter includes accuracy and time required for detection. Simulation results presented in this paper show that the proposed algorithm is effective in detecting attacks ahead in time.
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Byrne, Paul. "Research Summary and Literature Review on Modelling and Simulation of Heat Pumps for Simultaneous Heating and Cooling for Buildings." Energies 15, no. 10 (May 11, 2022): 3529. http://dx.doi.org/10.3390/en15103529.
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A heat pump for simultaneous heating and cooling (HPS) is a refrigeration machine by which the productions of heating and cooling energies are simultaneously valorized. This introductory article presents the uses of heat pump productions under the form of an analysis of thermal demands of different types of buildings and a literature review of real installations and experimental systems, which are the basis of the construction of numerical models. The applications of HPSs are diverse: space heating and cooling, domestic hot water (DHW), hot water for desalination process, etc. Means and methods for improving the performance of refrigeration cycles and the management of heat and cold productions are developed, including modeling and simulation. New refrigeration circuit architectures were designed. A focus is paid on refrigerants. Prototypes combining heating-cooling, heating-cooling-DHW and cooling-desalination have been developed, built and tested to validate the models. Even though a strong simultaneity of thermal demands is essential, the results show that HPSs are generally very efficient systems.
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Brzeziński, Mariusz, and Dariusz Pyza. "CARBON DIOXIDE EMISSION FROM DIESEL ENGINE VEHICLES IN INTERMODAL TRANSPORT." Transport 36, no. 3 (September 14, 2021): 246–59. http://dx.doi.org/10.3846/transport.2021.15484.
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Currently, many logistics operators operate in both domestic and foreign markets using various forms of transport organization. Choosing a corresponding technology and appropriate form of transport has an influence not only delivery time and costs, but also has an impact on the environment as a whole. There is a plethora of public research available in global literature discussing various ways of exploiting transport. On the other hand, there is a lack of complex studies detailing carbon emissions coming from transport activity. Specifically, where a theory of organic fuel combustion in the form of a chemical reaction with oxygen is considered. To fill this gap, we offer an innovative Emission Model of Industrial Sources (EMIS) method. This method makes it possible to determine the amount of CO2 emitted into the atmosphere during various transport methods. It also enables us to estimate, in terms of CO2 output, a threshold where transport of containers via combined mode becomes more favourable for the environment, than road transport. We ran a simulation of our algorithm to create boundary conditions. This let us prepare a regression function of CO2 emission, for intermodal and road transport as a function of various transport distances. The simulation results suggest that our approach may be used by supervisory institutions, which are responsible further developing and utilizing combined transport.
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Wang, Jian-Jun, Xiao-Feng Sui, Shan-Po Jia, Zhong-Zhi Hua, and Si-Yao Wang. "Experimental Study on Sealing Failure Mechanism of Injection-Production String in Underground Gas Storage under Cyclic Loading." Advances in Materials Science and Engineering 2022 (August 25, 2022): 1–14. http://dx.doi.org/10.1155/2022/5206149.
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In order to clarify the impact of cyclic loading on the mechanical properties and sealing performance of threaded connections on pipe string under the injection-production conditions of gas storage and the airtight threaded connections suitable for the actual working conditions can be preferred, the sealing failure of injection and production tubular strings of several domestic gas storages was investigated comprehensively. It was found that the airtight threaded connections with different performance may leak during the service of tubular strings. Existing standards and testing methods have limitations, which are not fully applicable to the working environment of gas storage wells and the production mode of forced injection-production and cannot reflect the operation characteristics of multiround injection and production. Based on the stress analysis of the tubular string during injection and production, a full-scale simulation testing of 30 cycles of gas seal cycle under alternating load was proposed. The cyclic loading test results of two P110·13Cr tubing in domestic gas storage showed that after 30 cycles of cyclic loading, the yield strength, internal pressure strength, collapse strength, and compressive bearing capacity of tubing were all decreased; the compression efficiency of the joints should be fully considered when selecting the gas-sealed thread.
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Onat, Cem. "WGC Based Robust and Gain Scheduling PI Controller Design for Condensing Boilers." Advances in Mechanical Engineering 6 (January 1, 2014): 659051. http://dx.doi.org/10.1155/2014/659051.
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This paper addresses the water temperature PI control in condensing domestic boilers. The main challenge of this process under the controller design perspective is the fact that the dynamics of condensing boilers are strongly affected by the demanded water flow rate. First, a robust PI controller based on weighted geometrical center method is designed that stabilizes and achieves good performance for closed-loop system for a wide range of the water flow rate. Then, it is shown that if the water flow rate information is used to update the controller gains, through a technique known as gain scheduled control, the performance can be significantly improved. Important characteristics of these PI design approaches are that the resulting parameters are calculated numerically without using any graphical method or iterative optimization process and that it guarantees the stability of the closed-loop. Significantly, simulation results have demonstrated that the proposed tuning techniques can perform better for set point changes and load disturbance than other available methods in the literature.
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Wang, Chun, Wenxu Yan, Wenyuan Wang, Hongyu Ni, and Jie Chu. "The Suppression of Modular Multi-Level Converter Circulation Based on the PIR Virtual Impedance Strategy." World Electric Vehicle Journal 14, no. 1 (January 5, 2023): 17. http://dx.doi.org/10.3390/wevj14010017.
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In recent years, with the rise of the electric vehicle industry, there has been significant research on charging and power supply vehicle technologies for electric vehicles. In terms of the corresponding converter usage, modular multi-level converters (MMCs) are also increasingly used in the field of electric vehicle power supply research because of their unique advantages. However, the circulating current problem of MMCs has not been effectively addressed in existing domestic and international studies. In this paper, we propose a proportional-integral resonant (PIR) control method combined with virtual impedance for the optimal suppression of the MMC internal circulating current problem based on the comparison and generalization of the existing methods. Based on the analysis of the working principle of MMCs, this paper proposes and adopts the control strategy of combining virtual impedance and proportional-integral resonance to suppress the circulating current and builds a simulation model in MATLAB to verify that the control strategy proposed in this paper is feasible.
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Goswami, Kuheli, and Arindam Kumar Sil. "Improvement of Energy Performance Index for Domestic Prosumers Based on Newly Proposed Dynamic Tariff and Rule-Based Strategy." International Transactions on Electrical Energy Systems 2022 (August 25, 2022): 1–12. http://dx.doi.org/10.1155/2022/5087908.
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A smart and intelligent energy management system (SIEMS) can make the existing system more reliable, robust, and cost-effective to deal with the present power scenario. This also initiates the necessity to develop a new dynamic tariff system and integrate renewable energy sources (RES) along with the conventional grid which in turn reduces carbon emission. Many countries have adopted different strategies for energy conservation based on energy conservation code, the main aim of which is to enforce design and development of household appliances for efficient power consumption. From data provided by utility sectors, it has been found that even in few countries 25% to 28% of the total energy is consumed by domestic sector and 45% of other residential loads also contribute a major part of the total domestic load consumed in any country. As a whole, residences, which consist of light electrical loads and home appliances constitute prosumers. The total energy consumed by prosumers is also intended by Bureau of energy efficiency, to make them fall under these codes (Energy Conservation Building Code) so that they can be treated on a scale of 1 star to 5 stars. This in turn will help in improving the energy performance index (EPI). In this paper, the optimal scheduling model of household appliances and energy storage system (ESS) has been designed based on the availability of renewable energy sources and newly proposed dynamic tariff system. To validate the efficiency of the model, we have comparatively evaluated the performance of the model with different feature selection methods and optimization techniques. A case study has been done and it has been found that the weighted K nearest neighbor method for feature selection and hybrid greedy particle swarm optimization (HGPSO) technique for optimization are performing better than other existing methods. The proposed model reflects the cost-effectiveness and improvement in EPI for prosumers.
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Woo, Namsub, Sangmok Han, Youngju Kim, Sunchul Huh, and Hyunji Kim. "Study on the structural stability evaluation of umbilical winch for ROV LARS." Engineering Computations 35, no. 1 (March 5, 2018): 202–10. http://dx.doi.org/10.1108/ec-03-2017-0107.
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Purpose The purpose of this study is structural stability evaluation of umbilical winch. In accordance with the recent trend for developing natural resources, high-technology equipment on exploration ships is becoming more technologically advanced. One such piece of high-technology equipment is the umbilical winch. In this study, the umbilical winch is divided into two parts (drum and winch), where each is respectively designed with three dimensional models using CATIA, and dynamic simulation and structural analysis are performed using ANSYS. Design/methodology/approach In this paper, the winch is divided into two parts for finite element analysis, the drum and whole winch model, and the parts are designed as three-dimensional models except for some small parts, such as bolt holes. Dynamic simulation and structural analysis are then performed using ANSYS. The analysis results ensure the reliability of the design methods and will be used in the domestic localization of remote operated vehicle (ROV) launch and recovery systems (LARS). Findings The strain is identified from the results, but it is very small. Some stress is concentrated at the lower corner of the drum, but the maximum stress value is lower than the allowable stress; therefore, the structure has no impact on the strain and stress. Thus, it is determined that the designed structure is safe. The results ensure the reliability of the design methods and will be used in the domestic localization of ROV LARS. Originality/value Previous studies focus on the static and mechanic problems of the winch by considering winch and drum breakage in the umbilical winch system. However, ships have a nonlinear motion characteristic with six degrees of freedom according to the constant influence of the external environment. In addition, from a design perspective, the dynamic characteristics (e.g. the ship’s motions) are more important than the static characteristics. Thus, the authors focus on winch stability securement with variable loads, such as ships moving, wave disturbance and other such important environment conditions.
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Arı, Emin Sertaç, and Cevriye Gencer. "The use and comparison of a deterministic, a stochastic, and a hybrid multiple-criteria decision-making method for site selection of wind power plants: An application in Turkey." Wind Engineering 44, no. 1 (May 17, 2019): 60–74. http://dx.doi.org/10.1177/0309524x19849831.
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Clean domestic energy is an attractive option, especially for developing countries. Wind has been one of the most appealing renewable energy sources for those as of the beginning of the 20th century. This study focuses on an important work item of the establishment phase of this important energy source: power plant site selection. Three approaches were examined based on multiple-criteria decision-making methods. Stochastic multi-criteria acceptability analysis (a simulation-based approach with different kinds of uncertain information), analytic hierarchy process (a conventional deterministic approach), and AHP-SMAA (a hybrid approach) were applied separately in Turkey. In terms of novelty, analyses were conducted both with (analytic hierarchy process) and without (stochastic multi-criteria acceptability analysis) the preference information of the decision makers. The unique hybrid method integrates stochastic multi-criteria acceptability analysis with analytic hierarchy process to allow the simulation-based experiments with deterministic variables. As a result of the approaches, the same region (Burhaniye-Pelitköy) showed up as the optimal site to establish wind power plants at every turn. The techniques are globally applicable as long as the computational data and all parameters are gathered completely.
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Fedorov, Vladimir, Maksim Nagorkin, and Leonid Vayner. "METHODOLOGICAL FOUNDATIONS OF DIAGNOSTICS OF METALWORKING TECHNOLOGICAL SYSTEMS ACCORDING TO PARAMETRIC RELIABILITY OF ENSURING A GIVEN QUALITY OF THE TREATED SURFACES." Bulletin of Bryansk state technical university 2021, no. 11 (November 15, 2021): 36–50. http://dx.doi.org/10.30987/1999-8775-2021-11-36-50.
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The paper presents the results of research justifying the need for diagnostics of metalworking technological systems on the reliability of ensuring the quality parameters of the surfaces of machine parts during machining. The fundamentals of the methodology of its implementation have been developed. Theoretical models of forming the quality parameters of parts surfaces during machining are considered and refined. This characterizes the scientific novelty of the results obtained. Circuitries for the construction of experimental control systems when conducting bench tests of machined surfaces of parts in conditions close to operational are of practical value. Circuitries are developed and computerized systems based on them for measuring the quality parameters of machined parts surfaces, including the working area of the technological system, are implemented. Recommendations on the rational choice of technological systems and the use of simulation methods in the study of parametric reliability of technological systems are presented. Mathematical and software analysis and processing of experimental results are developed and tested. These results will serve as a foundation for further development of research in the field of parametric reliability of technological systems, improving the quality of domestic engineering products and increasing their competitiveness at the world market.
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Djennah, Karim, Abdelaziz Ladjimi, and Abdesselam Babouri. "In Vitro Modeling of Implantable Cardiac Pacemakers Submitted to Conducted Disturbance." International Journal of Online and Biomedical Engineering (iJOE) 18, no. 01 (January 26, 2022): 65–77. http://dx.doi.org/10.3991/ijoe.v18i01.27289.
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The work presented describes the modeling of a measurement bench in the presence of an implantable single-chamber pacemaker in vitro subjected to a conducted disturbance. The source of disturbance is a sinusoidal electrical signal with amplitude of 10 V; the frequency ranges studied correspond to the frequencies of the electrical distribution network (50/60 Hz) and to the frequencies of domestic applications (10/25KHz). The numerical simulations were carried out according to two methods, the first based on the finite element method using the Comsol multiphysics software, the second is based on the impedance method. The results obtained by the two methods are in good agreement, and this will allow us to calculate the voltage induced between the ends of the stimulator. These results allowed us to validate the proposed model.
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Blad, Christian, Simon Bøgh, and Carsten Kallesøe. "A Multi-Agent Reinforcement Learning Approach to Price and Comfort Optimization in HVAC-Systems." Energies 14, no. 22 (November 9, 2021): 7491. http://dx.doi.org/10.3390/en14227491.
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This paper addresses the challenge of minimizing training time for the control of Heating, Ventilation, and Air-conditioning (HVAC) systems with online Reinforcement Learning (RL). This is done by developing a novel approach to Multi-Agent Reinforcement Learning (MARL) to HVAC systems. In this paper, the environment formed by the HVAC system is formulated as a Markov Game (MG) in a general sum setting. The MARL algorithm is designed in a decentralized structure, where only relevant states are shared between agents, and actions are shared in a sequence, which are sensible from a system’s point of view. The simulation environment is a domestic house located in Denmark and designed to resemble an average house. The heat source in the house is an air-to-water heat pump, and the HVAC system is an Underfloor Heating system (UFH). The house is subjected to weather changes from a data set collected in Copenhagen in 2006, spanning the entire year except for June, July, and August, where heat is not required. It is shown that: (1) When comparing Single Agent Reinforcement Learning (SARL) and MARL, training time can be reduced by 70% for a four temperature-zone UFH system, (2) the agent can learn and generalize over seasons, (3) the cost of heating can be reduced by 19% or the equivalent to 750 kWh of electric energy per year for an average Danish domestic house compared to a traditional control method, and (4) oscillations in the room temperature can be reduced by 40% when comparing the RL control methods with a traditional control method.
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Ma, Kaichao, Changhong Tang, Jianye Zhang, Xiaofei Niu, and Qingzhi Fan. "Flight Load Design of Nacelle of Carrier-Based Propeller Transport Aircraft." Xibei Gongye Daxue Xuebao/Journal of Northwestern Polytechnical University 38, no. 6 (December 2020): 1249–56. http://dx.doi.org/10.1051/jnwpu/20203861249.
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The carrier-based propeller transport aircraft has a compact layout, where the large nacelle in size and weight is sensitive to propeller slipstream, and thus calls for sophisticated flight load design studies, which are still insufficient considering domestic experience. In detail, the design methods on aerodynamic load, inertial load, gyrostatic moment, as well as studies on design criteria and maneuver simulation technology are shown for a reference aircraft. The design range applied to this nacelle's flight load is firstly determined by understanding and selecting the design criteria. The typical loadcases of the nacelle are derived from aircraft maneuver simulation. The data of pressure distribution under a series of propeller slipstream strengths is obtained by CFD method. The Design Loads and Design Loadcases of the nacelle are calculated and selected. The effects of the propeller slipstream are compared in an example of the increment on aerodynamic load in a maneuver. The results show that the Design Loads of the nacelle are obtained from the abrupt pitching maneuver under the maximum normal load factor (Nz), the yawing maneuver under the Design Dive Speed(VD), and the maximum propeller pull under the maximum landing weight; the transverse loads of the nacelle are dominated by the aerodynamic load, and the normal loads are dominated by the inertial load, in which the inertial force exceeds the aerodynamic force by 4 times under the extreme circumstances. In some manoeuvres or status, the total aerodynamic force of the whole nacelle is increased by above 90% due to propeller slipstream; the front part of the nacelle which is close to the propeller sees a much bigger increment.
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Mokritskiy, B. Y., and E. S. Sitamov. "Tool Materials for Turning Machine-Building Stainless Steel 09Kh17N7Yu." Proceedings of Higher Educational Institutions. Маchine Building, no. 1 (730) (January 2021): 27–33. http://dx.doi.org/10.18698/0536-1044-2021-1-27-33.
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Hard-to-process specialized stainless steel grade 09Kh17N7Yu has become widely used in various fields of mechanical engineering due to its unique performance properties. The existing recommendations for its processing are outdated and do not meet modern requirements for the performance of metal-cutting tools. This necessitated the need to develop recommendations for modern high-performance machine tools. The paper presents methods of solving this problem based on the example of turning by typical domestic replaceable hard-alloyed cutting plates. Relationships between the tool wear and the operating time were obtained. Design solutions for tool materials to be used under specified operating conditions were developed. A significant outcome of the paper was the use of simulation modeling in the Deform software environment, which allowed the authors to develop new coatings for the hard alloy VK8, which provided a significant (up to 3 times) increase in tool life. Using modelling, it was also possible to design new tool materials for new or expected operating conditions. The following main criteria sufficient for modeling were identified: tool wear, temperature in the cutting zone, stresses in the tool material and deformation of the tool material. The results obtained can be used as the basis for the so-called data bank, which can be used in production enterprises.
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Taler, Dawid, Jan Taler, Tomasz Sobota, and Jarosław Tokarczyk. "Cooling Modelling of an Electrically Heated Ceramic Heat Accumulator." Energies 15, no. 16 (August 22, 2022): 6085. http://dx.doi.org/10.3390/en15166085.
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This paper presents a simple novel mathematical model of a heat accumulator with an arranged packing in the form of ceramic cylinders. The accumulator analysed in the paper can be heated with inexpensive electricity overnight or excess electricity from wind farms. It can be used as a heat source in a hydronic heating system or for domestic hot water. The differential equations describing the transient temperature of the accumulator packing and flowing air were solved using the explicit Euler and Crank–Nicolson methods. The accuracy of both methods was assessed using exact analytical solutions and the superposition method for a uniform initial temperature and accounted for time changes in inlet air temperature. A numerical simulation of the accumulator cooled by flowing air was carried out. The correlation for the air-side Nusselt number was determined using the method of least squares based on experimental data. The calculated exit air temperature was compared with the measured data. The accumulator can operate as a heat source with dynamic discharge. The developed mathematical model of the accumulator can be used in a system to adjust the fan rotational speed so that the air temperature in the room is equal to the preset temperature.
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Kim, Young-Hwi, Jin-Seok Choi, Tian-Feng Yuan, and Young-Soo Yoon. "Evacuation of Shelter in Place at Subway Transfer Stations Based on BIM and Proposal of a Strengthening Method." Buildings 12, no. 11 (November 15, 2022): 1981. http://dx.doi.org/10.3390/buildings12111981.
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Among public facilities, facilities belonging to Multi-Group (I) include high-rise buildings, tunnels, and subway stations, and the location of Shelter in Place (SIP) is an important factor in the safety of citizens. However, subway evacuation maps usually induce evacuation to ground level or the tunnel of a subway platform without considering the location of SIP. In other words, since the location of the SIP is not determined, conditions, such as ventilation, air conditioning facilities, and structural durability required for the SIP cannot be satisfied. It is difficult to suggest the location of SIP because the domestic standards limit only the time it takes to move from the outside to the facility designated as SIP during an emergency evacuation. Therefore, in this study, when there is a situation of emergency evacuation in the subway, the total allowed time to evacuate to SIP is limited to 6 min. We designate a space that can accommodate the number of evacuees at the location and compare and analyze the results of the evacuation simulation using six scenarios. Additionally, suggestions are made for improvement methods relating to evacuation as well as the proposal of reinforcement methods through an experiment to satisfy the structural requirements of SIP in subway stations.
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Kunche, Akhil, and Bożena Mielczarek. "Application of System Dynamic Modelling for Evaluation of Carbon Mitigation Strategies in Cement Industries: A Comparative Overview of the Current State of the Art." Energies 14, no. 5 (March 8, 2021): 1464. http://dx.doi.org/10.3390/en14051464.
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Cement is the key ingredient in concrete, which is the most consumed resource on the planet after water. As an energy-intensive industry, cement production is one of the largest sources of greenhouse emissions in the world today. The demand for cement is synonymous with the growth in infrastructure demand and per-capita gross domestic product in the world, calling the need for mitigation measures within the industry in order to contribute to the global climate change efforts. System dynamics (SD) is a simulation approach that is used for studying the nonlinear behaviours in complex systems over time, often used in industrial domains for emission forecasts as well as policy experimentation. With the adoption rates of mitigation strategies in the cement industry being inadequate, there is a need for improvisation in policymaking through better decision-support tools. In this paper, a comparative overview of the studies that specifically utilise the SD approach for evaluation of carbon mitigation strategies in the cement industry is presented on the basis of their scope, model description, scenarios tested, and featured mitigation methods. Additionally, the potential for improvements in future studies is discussed.
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Dou, Xun, Li Song, Shengnan Zhang, Lulu Ding, Ping Shao, and Xiaojun Cao. "Multi-Time Scale Trading Simulation of Source Grid Load Storage Based on Continuous Trading Mechanism for China." Sensors 22, no. 6 (March 18, 2022): 2363. http://dx.doi.org/10.3390/s22062363.
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The proportion of new energy in power systems is increasing yearly. How to deal with the adverse impact of new energy output uncertainty on its participation in trading from the mechanism level is an urgent problem in China that must be solved. A source grid load storage (SGLS) continuous trading mechanism and a multi-time scale trading simulation method are proposed which meet the needs of Chinese new energy consumption and satisfies the trading needs of Chinese power market players. Firstly, the connection mechanism of mid-long term, day-ahead, and intra-day SGLS interactive trading is established, and the meaning and ways of continuous development are defined. Secondly, the clearing model of SGLS trading based on the continuous trading mechanism is established to provide mathematical models and strategic methods for various resources to participate in SGLS trading. Then, the multi-time scale trading simulation of SGLS based on the continuous trading mechanism is carried out to obtain the trading strategies of different trading subjects. The example results show that compared with the trading mechanism based on deviation assessment, the one-day trading cost is reduced by 4.20% and the consumption rate of new energy is increased by 6.53%. It can be seen that the mid-long term–day-ahead–day SGLS interactive trading connection mechanism has advantages in reducing trading costs and improving the consumption rate of new energy. It can flexibly deal with the trading scenario of domestic new energy consumption and new energy reverse peak shaving, which has an effect on the adverse impact of trading and operation deviation caused by source load uncertainty on trading.
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Słota-Valim, Małgorzata, Andrzej Gołąbek, Wiesław Szott, and Krzysztof Sowiżdżał. "Analysis of Caprock Tightness for CO2 Enhanced Oil Recovery and Sequestration: Case Study of a Depleted Oil and Gas Reservoir in Dolomite, Poland." Energies 14, no. 11 (May 25, 2021): 3065. http://dx.doi.org/10.3390/en14113065.
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This study addresses the problem of geological structure tightness for the purposes of enhanced oil recovery with CO2 sequestration. For the first time in the history of Polish geological survey the advanced methods, practical assumptions, and quantitative results of detailed simulations were applied to study the geological structure of a domestic oil reservoir as a potential candidate for a combined enhanced oil recovery and CO2 sequestration project. An analysis of the structure sequestration capacity and its tightness was performed using numerical methods that combined geomechanical and reservoir fluid flow modelling with a standard two-way coupling procedure. By applying the correlation between the geomechanical state and transport properties of the caprock, threshold pressure variations were determined to be a key factor affecting the sealing properties of the reservoir–caprock boundary. In addition to the estimation of the sequestration capacity of the structure, the process of CO2 leakage from the reservoir to the caprock was simulated for scenarios exceeding the threshold pressure limit of the reservoir–caprock boundary. The long-term simulations resulted in a comprehensive assessment of the total amount of CO2 leakage as a function of time and the leaked CO2 distribution within the caprock.
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Ma, Chenyu, Jianlin Liu, Hongyan Li, and Jiading Zhong. "Impact Assessment of Waste Odor Source Locations on Pedestrian-Level Exposure Risk." Buildings 12, no. 5 (April 21, 2022): 528. http://dx.doi.org/10.3390/buildings12050528.
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Poor wind environment in residential areas leads to the accumulation of odor from domestic waste, affecting pedestrian health. A reasonable arrangement of waste collection points can reduce pedestrian exposure risks. This study aims to investigate the hydrogen sulfide (H2S) dispersion and residents’ exposure risk at the pedestrian level for five different locations of waste collection points in a residential building array. Simulation results are consistent with the benchmark wind tunnel experiment, validating that the used turbulence model and numerical methods show good agreement with the predictions of the aforementioned problem. Results indicate that the dimensionless concentration of H2S and personal intake fraction in a residential area are lower when the collection point is at the corner of the building array periphery. When the collection point is located in the middle of the periphery of the building array or between two adjacent buildings in the center of the array, the local dimensionless concentration of H2S is 50 at the pedestrian level, and the personal intake fraction is three orders of magnitude higher than that at the corner of the building array periphery. The findings provide a reference for the layout of waste collection points in high-density residential areas and reduction in outdoor exposure risk.
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Lee, Seokjin, Minhan Kim, Seunghyeon Shin, Sooyoung Park, and Youngho Jeong. "Data-Dependent Feature Extraction Method Based on Non-Negative Matrix Factorization for Weakly Supervised Domestic Sound Event Detection." Applied Sciences 11, no. 3 (January 24, 2021): 1040. http://dx.doi.org/10.3390/app11031040.
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In this paper, feature extraction methods are developed based on the non-negative matrix factorization (NMF) algorithm to be applied in weakly supervised sound event detection. Recently, the development of various features and systems have been attempted to tackle the problems of acoustic scene classification and sound event detection. However, most of these systems use data-independent spectral features, e.g., Mel-spectrogram, log-Mel-spectrum, and gammatone filterbank. Some data-dependent feature extraction methods, including the NMF-based methods, recently demonstrated the potential to tackle the problems mentioned above for long-term acoustic signals. In this paper, we further develop the recently proposed NMF-based feature extraction method to enable its application in weakly supervised sound event detection. To achieve this goal, we develop a strategy for training the frequency basis matrix using a heterogeneous database consisting of strongly- and weakly-labeled data. Moreover, we develop a non-iterative version of the NMF-based feature extraction method so that the proposed feature extraction method can be applied as a part of the model structure similar to the modern “on-the-fly” transform method for the Mel-spectrogram. To detect the sound events, the temporal basis is calculated using the NMF method and then used as a feature for the mean-teacher-model-based classifier. The results are improved for the event-wise post-processing method. To evaluate the proposed system, simulations of the weakly supervised sound event detection were conducted using the Detection and Classification of Acoustic Scenes and Events 2020 Task 4 database. The results reveal that the proposed system has F1-score performance comparable with the Mel-spectrogram and gammatonegram and exhibits 3–5% better performance than the log-Mel-spectrum and constant-Q transform.
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Xiong, Pingping, Zhiqing He, Shiting Chen, and Mao Peng. "A novel GM(1,N) model based on interval gray number and its application to research on smog pollution." Kybernetes 49, no. 3 (June 3, 2019): 753–78. http://dx.doi.org/10.1108/k-12-2018-0694.
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Purpose In recent years, domestic smog has become increasingly frequent and the adverse effects of smog have increasingly become the focus of public attention. It is a way to analyze such problems and provide solutions by mathematical methods. Design/methodology/approach This paper establishes a new gray model (GM) (1,N) prediction model based on the new kernel and degree of grayness sequences under the case that the interval gray number distribution information is known. First, the new kernel and degree of grayness sequences of the interval gray number sequence are calculated using the reconstruction definition of the kernel and degree of grayness. Then, the GM(1,N) model is formed based on the above new sequences to simulate and predict the kernel and degree of the grayness of the interval gray number sequence. Finally, the upper and lower bounds of the interval gray number are deduced based on the calculation formulas of the kernel and degree of grayness. Findings To verify further the practical significance of the model proposed in this paper, the authors apply the model to the simulation and prediction of smog. Compared with the traditional GM(1,N) model, the new GM(1,N) prediction model established in this paper has better prediction effect and accuracy. Originality/value This paper improves the traditional GM(1,N) prediction model and establishes a new GM(1,N) prediction model in the case of the known distribution information of the interval gray number of the smog pollutants concentrations data.
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Verginadis, Dimosthenis, and Athanasios Karlis. "Design of a Management Algorithm for Energy Trading in Microgrids." Recent Advances in Electrical & Electronic Engineering (Formerly Recent Patents on Electrical & Electronic Engineering) 13, no. 7 (November 4, 2020): 1028–40. http://dx.doi.org/10.2174/2213111607666200214121935.
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Background: The scope of this paper is to study the energy trading in microgrids. Microgrids are low voltage or medium voltage distribution networks, which consist of energy storage systems, electric loads, e.g. electric vehicles and Renewable Energy Sources (RES). Methods: Legacy energy grids are being transformed by the introduction of small to medium sized individual or cooperative, mostly RES invested energy producers and prosumers. Electric vehicles penetrate the market and modern power grids integrate them as ancillary services providers when there are peak domestic loads, as well as in order to balance grid voltage aiming to increase system reliability, compensating for renewable energy sources’ intermittency and volatility in energy production. Results: An elaborate management algorithm is proposed in this paper, to balance demand and local renewable energy sources microgrid supply. Conclusion: Finally, the results of simulations of different scenarios, including economic parameters and proposals for future research are presented.
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Sornek, Krzysztof. "Study of Operation of the Thermoelectric Generators Dedicated to Wood-Fired Stoves." Energies 14, no. 19 (October 1, 2021): 6264. http://dx.doi.org/10.3390/en14196264.
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Thermoelectric generators are devices that harvest waste heat and convert it into useful power. They are considered as an additional power source in the domestic sector, but they can also be installed in off-grid objects. In addition, they are a promising solution for regions where there is a lack of electricity. Since biomass heating and cooking stoves are widely used, it is very appropriate to integrate thermoelectric generators with wood-fired stoves. This paper shows the experimental analysis of a micro-cogeneration system equipped with a wood-fired stove and two prototypical constructions of thermoelectric generators dedicated to mounting on the flue gas channel. The first version was equipped with one basic thermoelectric module and used to test various cooling methods, while the second construction integrated four basic thermoelectric modules and a water-cooling system. During the tests conducted, the electricity generated in the thermoelectric generators was measured by the electronic load, which allowed the simulation of various operating conditions. The results obtained confirm the possibility of using thermoelectric generators to generate power from waste heat resulting from the wood-fired stove. The maximum power obtained during the discussed combustion process was 15.4 W (if this value occurred during the entire main phase, the energy generated would be at a level of approximately 30 Wh), while the heat transferred to the water was ca. 750 Wh. Furthermore, two specially introduced factors (CPC and CPTC) allowed the comparison of developed generators, and the conclusion was drawn that both developed constructions were characterized by higher CPC values compared to available units in the market. By introducing thermoelectric modules characterized by higher performance, a higher amount of electricity generated may be provided, and sufficient levels of current and voltage may be achieved.
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Liu, Jinyong. "Design of Remote Environmental Monitoring Network Based on Intelligent Sensor Network Address Allocation and Addressing." Journal of Sensors 2021 (December 24, 2021): 1–9. http://dx.doi.org/10.1155/2021/5618538.
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Based on the wireless sensor network, this paper combines node monitoring data with intelligent network address management. Users can view real-time environmental data through a computer or mobile phone and can manually remotely manage the environmental adjustment equipment of the network address through the mobile phone. This article first discusses the research background of the subject, introduces the current domestic and foreign research status of WSN in environmental detection, and analyzes the reasons for choosing ZigBee network as the wireless transmission environment of the intelligent monitoring system. Secondly, the structure, layered model, and key technologies of wireless sensor networks are introduced, and it is pointed out that ZigBee technology, which has the characteristics of low power consumption, reliable communication, self-organization of the network, strong self-healing ability, and low cost, is very suitable for application in the environment. Then, it analyzes TI’s protocol stack Z-Stack based on the ZigBee2006 standard and analyzes the network address assignment and addressing in Z-Stack, the process and steps of node binding, the routing mechanism and routing maintenance, and channel configuration. The realization of other functions was discussed in depth. During the simulation experiment, in the hardware design of the intelligent monitoring system, the network node was divided into two parts: the core board and the backplane. The crystal oscillator, power supply, antenna, and I/O port circuits of the core board were designed, and the data acquisition, relay, and power supply of the backplane were designed. Finally, this paper studies the data security issues in the environmental monitoring network and proposes two solutions to control network access and data encryption. Experimental results show that in terms of low-power design, the energy of the entire system is calculated to determine the factors that affect the power consumption of the system and methods such as increasing the node sleep time to ensure that the system can work for a long time.
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Eriksson, Martin, Jan Akander, and Bahram Moshfegh. "Investigating Energy Use in a City District in Nordic Climate Using Energy Signature." Energies 15, no. 5 (March 5, 2022): 1907. http://dx.doi.org/10.3390/en15051907.
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This paper focuses on multi-family buildings in a Swedish city district, erected between 1965 and 1973, which are now in need of renovation. For the two types of multi-family buildings in the district, tower buildings and low-rise buildings, dynamic energy use is predicted by using an energy signature method. The energy signature is then used to calculate the primary energy use number of the building stock, according to calculations methods dictated by Swedish building regulations. These regulations are also used to assess which multi-family buildings are in need of renovation, based on the buildings’ primary energy use. For buildings that need energy renovations, it is simulated so that the energy use of each multi-family building complies with these same building regulations. The proposed methodology for simulating energy renovation also determines new energy signature parameters, related to building heat loss coefficient, balance temperature and domestic hot water usage. The effects of simulated renovation are displayed in a duration diagram, revealing how a large-scale renovation affects the district’s heat load in different annual periods, which affects the local district heating system. Sensitivity analysis is also performed before and after simulated energy renovation.
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Kryzhanivskyy, Ye І., О. Yu Vytyaz, and R. S. Hrabovskyi. "Assessment and prediction of robotic performance of long-term operated drill pipes." Scientific Bulletin of Ivano-Frankivsk National Technical University of Oil and Gas, no. 2(49) (December 30, 2020): 7–17. http://dx.doi.org/10.31471/1993-9965-2020-2(49)-7-17.
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The problem of monitoring and preventing deposit inundation is becoming increasingly important in Ukraine. The solution to this problem is one of the ways to ensure the energy independence of the state. The operation of producing wells is complicated by the accumulation of liquid at the bottom. Subsequently, it leads to premature shutdown of the wells. Inundation determines the need to isolate the influx of formation water. Considering the significant residual reserves of gas trapped in water, it is important to improve existing technologies and to develop new ones for the development of depleted fields under the conditions of dynamic water drive in order to ensure maximum hydrocarbon recovery rates. This paper summarizes domestic and foreign field development technologies under water pressure conditions and analyzes the main disadvantages and advantages of the existing methods of stimulating hydrocarbon inflows in waterlogged gas and gas condensate wells. The main factors that determine the causes and nature of flooding of productive formations and ways to prevent them are analyzed. Based on the results of the analysis of laboratory and experimental studies, the behavior of gas trapped by brine water has been established.But the issue of determining the localization of residual reserves has not been studied sufficiently. Considering the above mentioned ideas, the author asserts the necessity to and to use geological and technological models constantly. It ensures better extraction of the residual gas from depleted fields under the condition of intensive advance of reservoir water into productive formations. In the case of adapting the three-dimensional model to the actual data of the production history and the simulation of the exact breakthrough of produced water in production wells, there comes the possible to determine the most promising zones and sections of the field, the reservoirs of which are characterized by the best filtration-capacitive properties and significant gas reserves. The use of a constantly operating geological and technological model of the field will make it possible to develop ways of extracting the residual gas reserves trapped in produced water, to improve existing production technologies and to ensure maximum recovery factors.
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Liang, Dan. "Aesthetic Value Evaluation for Digital Cultural and Creative Products with Artificial Intelligence." Wireless Communications and Mobile Computing 2022 (July 1, 2022): 1–10. http://dx.doi.org/10.1155/2022/8318620.
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The domestic cultural and creative industry has abundant resource advantages and broad development space. The design for cultural and creative products has evolved rapidly with the objective to improve its quality. The cultural and creative industries have seen rapid growth in the recent years wherein digital technologies have been incorporated with the traditional methodologies. The digital cultural and creative aspect acts are extremely important in the dissemination of traditional culture on the network platform. This is also supported by the state vigorously to implement innovative industrial policies. However, the adoption of digital technology in the cultural and creative industry is a novel approach. But there exists lack of understanding in terms of its nature and development protocols. It is thus necessary to study relevant theories to guide the development of digital cultural and creative industry. The increasingly prosperous aesthetic culture, especially development for cultural and creative industries, has comprehensively improved aesthetic value of the cultural and creative products. Therefore, the methods to evaluate and realize the aesthetic value of digital, cultural, and creative products are extremely important and relevant in the present day and age. In this study, neural network is used to design an improved back propagation (BP) network in order to evaluate the aesthetic value of digital cultural and creative products. At the outset, the basic idea, structural characteristics, the learning algorithm, and its flow of functioning in the BP network are analyzed. Then, an aesthetic value evaluation model of digital cultural and creative products with BP network is developed. Next, considering the shortcomings of BP network, a segmentation adaptive strategy is used to improve the view field and step size for artificial fish swarm algorithm (AFSA). Finally, the improvised algorithm is verified wherein the simulation results reveal improvement in algorithm convergence speed as well as improvement in optimal solution accuracy as part of the adaptive improvement approach.
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Azeem, Fawad, Ashfaq Ahmad, Taimoor Muzaffar Gondal, Jehangir Arshad, Ateeq Ur Rehman, Elsayed M. Tag Eldin, Muhammad Shafiq, and Habib Hamam. "Load Management and Optimal Sizing of Special-Purpose Microgrids Using Two Stage PSO-Fuzzy Based Hybrid Approach." Energies 15, no. 17 (September 5, 2022): 6465. http://dx.doi.org/10.3390/en15176465.
Full textAbstract:
The sizing of microgrids depends on the type of load and its operational hours. The significance of understanding the load operational characteristics in special purpose islanded microgrids is much needed for economic system sizing. The load operation of special-purpose microgrids often consumes high power for a short duration and remains idle most of the time, thus reducing the load factor. The inclusion of such loads in microgrid sizing causes huge capital costs making islanded microgrids an unfeasible solution. The islanded microgrid under study is an agricultural microgrid in a village having a small Crab Processing Plant (CPP) and a Domestic Sector (DS). The CPP constitutes the major power consumption. The community has a unique load consumption trend that is dependent on the highly uncertain parameter of availability of the crabs. Interestingly, crab availability is an independent parameter and cannot be accurately scheduled. The existing system sizing of the microgrid is performed based on the conventional methods that consider the CPP for full-day operation. However, the microgrid sources, especially the storage system may be reflected as oversized if the crab processing plants do not operate for several days due to the uncertain behavior of CPP causing enormous power wastage. In this paper, an integrated fixed and operational mode strategy for uncertain heavy loads is formulated. The proposed algorithm is based on the optimal sizing methodology aided by the load scheduling control strategy. The Particle Swarm Optimization technique is used for the optimal sizing integrated with the fuzzy logic controller to manage the available load. The membership functions are available excess power and the state of the charge of storage that defines the operational conditions for CPP. Based on input membership functions, the fuzzy controller decides on power dispatch in DS or CPP, keeping considerable SoC available for night hours. The simulation result shows that the time-dependent fuzzy controller approach manages to provide power to both sectors under optimal sizing while reducing the overall cost by 24% less than the existing microgrid.
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Porteiro, Rodrigo, Juan Chavat, and Sergio Nesmachnow. "A Thermal Discomfort Index for Demand Response Control in Residential Water Heaters." Applied Sciences 11, no. 21 (October 27, 2021): 10048. http://dx.doi.org/10.3390/app112110048.
Full textAbstract:
Demand-response techniques are crucial for providing a proper quality of service under the paradigm of smart electricity grids. However, control strategies may perturb and cause discomfort to clients. This article proposes a methodology for defining an index to estimate the discomfort associated with an active demand management consisting of the interruption of domestic electric water heaters. Methods are applied to build the index include pattern detection for estimating the water utilization using an Extra Trees ensemble learning method and a linear model for water temperature, both based on analysis of real data. In turn, Monte Carlo simulations are applied to calculate the defined index. The proposed approach is evaluated over one real scenario and two simulated scenarios to validate that the thermal discomfort index correctly models the impact on temperature. The simulated scenarios consider a number of households using water heaters to analyze and compare the thermal discomfort index for different interruptions and the effect of using different penalty terms for deviations of the comfort temperature. The obtained results allow designing a proper management strategy to fairly decide which water heaters should be interrupted to guarantee the lower discomfort of users.