IF 0.5 4区工程技术

Kerntechnik Pub Date : 2023-12-07 DOI: 10.1515/kern-2023-0030

A. Adail, M. H. Saad, A. Said

{"title":"Evaluation of the optimum safety performance of the nuclear reactor compact grounding system under lightning strikes and ground fault","authors":"A. Adail, M. H. Saad, A. Said","doi":"10.1515/kern-2023-0030","DOIUrl":"https://doi.org/10.1515/kern-2023-0030","url":null,"abstract":"Abstract The electrical system of a nuclear reactor facility (NRF) must incorporate a grounding grid in order to ensure it functions safely and reliably. Any disturbance in the electrical system affects the nuclear process, so it is, therefore, crucial to estimate the safety performance of the research nuclear reactor facility grounding system. The paper discusses CYMGrd 6.3, which is based on IEEE Standard 80-2013, and the optimization approaches for finding the best grounding grid design for a nuclear reactor facility connected substation of 500/11 kV in the case of a ground fault and lightning strikes. The result shows that the surface, step and touch potentials along the diagonal coordinates of the proposed grounding grid are below the safety limits in case of a ground fault but also results indicate that 100 kA lightning stroke poses a considerable threat to reactor equipment and personnel safety because the measured grid surface potential exceeds the safe ground potential rise of 3.2 kV standard at the striking point in conjunction with the proposed ground grid, so it must be modified. In this paper, three different optimization algorithms are investigated in order to determine the optimal design of the grounding grid with respect to mesh size: gradient method (GM), the genetic algorithm (GA), and simulated annealing (SA). These methods are used to achieve the purpose of obtaining an effective ground grid design. Comparing these techniques of GM and SA is good for quickly locating local minima, but they may fail to identify global solutions. In contrast, a genetic algorithm is often excellent at achieving a global minimum. Also, the utilization of GA, SA, and GM achieve the reduction of the surface potential of a proposed grounding grid by 16 %, 10 %, and 6 % respectively.","PeriodicalId":17787,"journal":{"name":"Kerntechnik","volume":"14 9","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138591585","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

CFD and machine learning based hybrid model for passive dilution of helium in a top ventilated compartment 基于CFD和机器学习的顶部通风舱内氦被动稀释混合模型

4区工程技术

Kerntechnik Pub Date : 2023-11-15 DOI: 10.1515/kern-2023-0079

Pavan K. Sharma, Vishnu Verma, Jayanta Chattopadhyay

{"title":"CFD and machine learning based hybrid model for passive dilution of helium in a top ventilated compartment","authors":"Pavan K. Sharma, Vishnu Verma, Jayanta Chattopadhyay","doi":"10.1515/kern-2023-0079","DOIUrl":"https://doi.org/10.1515/kern-2023-0079","url":null,"abstract":"Abstract For hydrogen management in the containment of Nuclear Power Plants (NPPs), besides the Passive autocatalytic Recombiners (PAR), the passive dilution of lighter gas plays an important role. This could be an attractive option to optimize the containment design and to estimate the extent of dilution. Passive dilution has many other applications in nuclear industry. The experimental studies of air entrainment in the upward rising helium plume and the resulting dilution of helium gas by the Canadians in terms of Volume Flow Magnification Factor (VFMF) have been utilized for Computational Fluid Dynamics (CFD) validation. The CFD based Fire Dynamics Simulator (FDS) predicted values of VFMF found to be in good agreement with the test data. After FDS code validation, parametric study has been carried out to generate a data base of VFMF for range of hydrogen injection, side opening area and opening height. In present study various Machine Learning (ML) models are evaluated based on two-parameter relationship i.e. non dimensional hydrogen injection and VFMF using the CFD code generated database. The trained ML models were used for the predictions of the mass flow rate of gas entrainment (through opening) in the rising buoyant plume in terms of VFMF. The ML predictions were in good agreement with the predictions against test data. Multivariate Adaptive Regression Splines (MARS) based ML model found to performed best and discussed in the paper. The paper highlights details of methodology of numerical simulation, results of the CFD studies and machine learning based predictions.","PeriodicalId":17787,"journal":{"name":"Kerntechnik","volume":"3 9","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136229687","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Probing ⁶He induced reactions with nuclear level density 他诱导的反应具有核级别的密度

4区工程技术

Kerntechnik Pub Date : 2023-11-10 DOI: 10.1515/kern-2023-0056

Deniz Canbula, Bora Canbula, Halil Babacan

引用次数: 0

Neutronic and thermal-hydraulic assessment of the TRR with new core designed based on tubular fuels 基于管状燃料设计的新型堆芯TRR的中子和热水力评价

4区工程技术

Kerntechnik Pub Date : 2023-11-09 DOI: 10.1515/kern-2023-0042

Rahman Gharari, Farrokh Khoshahval, Mostafa Hasanzadeh, M. Amin Mozaffari, M. Amin Amirkhani, Hadi Esmaili

引用次数: 0

An application for nonlinear heterogeneity-based isotherm models in characterization of niobium sorption on clay rocks and granite 基于非线性非均质性的等温线模型在黏土和花岗岩上铌吸附特性的应用

4区工程技术

Kerntechnik Pub Date : 2023-11-08 DOI: 10.1515/kern-2023-0059

Shih-Chin Tsai, Pei-Tung Hsueh, Kuan-Ying Hsieh, Hui-Min Chiu, Chuan-Pin Lee

引用次数: 0

Experimental investigation of heat transfer characteristics of inclined aluminium two phase closed thermosyphon 倾斜铝两相封闭热虹吸管传热特性的实验研究

4区工程技术

Kerntechnik Pub Date : 2023-11-08 DOI: 10.1515/kern-2023-0045

Sachin V. Mutalikdesai, Ajit M. Kate, Tarang R. Shinde, Naveen Kumar Gupta, Hitesh Panchal, L. Natrayan, Radhey Shyam Meena, Md Irfanul Haque Siddiqui, Anand Patel, Abhinav Kumar

{"title":"Experimental investigation of heat transfer characteristics of inclined aluminium two phase closed thermosyphon","authors":"Sachin V. Mutalikdesai, Ajit M. Kate, Tarang R. Shinde, Naveen Kumar Gupta, Hitesh Panchal, L. Natrayan, Radhey Shyam Meena, Md Irfanul Haque Siddiqui, Anand Patel, Abhinav Kumar","doi":"10.1515/kern-2023-0045","DOIUrl":"https://doi.org/10.1515/kern-2023-0045","url":null,"abstract":"Abstract A reduction in the size of electronic equipment increases the heat generation rate. Failure of electronic equipment occurs if the heat is not dissipated properly. This paper examines the performance of aluminium two-phase closed thermosyphon for cooling electronic equipment. Acetone charged aluminium two-phase closed thermosyphon was fabricated with an inside diameter of 17.05 mm and 1 mm thickness. A series of experimentations were performed for inclination angles of 10°–90° at selected filling ratios of 30, 60 and 100 %, along with heat inputs of 100, 200 and 300 W. The condenser section flow rate of water was maintained constant. Minimum thermal resistance was obtained at a 30° inclination angle for all filling ratios and heat inputs. The evaporator and condenser sections have a maximum heat transfer coefficient at a 30° inclination angle. Thermosyphon, with a 30 % or 60 % filling ratio, performed better than a 100 % filling ratio for all inclination angles and heat inputs. As the heat input was increased, the heat transfer coefficients of the evaporator and condenser section were increased, whereas total thermal resistance decreased. For 300 W heat input and 30 % filling ratio, the minimum thermal resistance at a 30° inclination angle was 0.158 °C/W. It is found that, the same heat input and filling ratio, the maximum heat transfer coefficient value for the evaporator and condenser section at a 30° inclination angle was 1602 W/m 2 °C and 5652 W/m 2 °C, respectively.","PeriodicalId":17787,"journal":{"name":"Kerntechnik","volume":" 12","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135340597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Optimization strategy for SAM in nuclear power plants based on NSGA-II 基于NSGA-II的核电厂SAM优化策略

4区工程技术

Kerntechnik Pub Date : 2023-11-08 DOI: 10.1515/kern-2023-0036

Sikai Zhou, Mingliang Xie, Jianxiang Zheng, Huifang Miao

{"title":"Optimization strategy for SAM in nuclear power plants based on NSGA-II","authors":"Sikai Zhou, Mingliang Xie, Jianxiang Zheng, Huifang Miao","doi":"10.1515/kern-2023-0036","DOIUrl":"https://doi.org/10.1515/kern-2023-0036","url":null,"abstract":"Abstract The Severe Accident Management Guide (SAMG) is an important component of nuclear safety regulations. Many studies are being conducted to optimize severe accident management (SAM) strategies. To ensure the safety of nuclear power plants, decision makers need to monitor multiple parameters with security threats. Therefore, it is particularly important to search optimal SAM strategies under different numbers of mitigation targets. The Non-dominated Sorting Genetic Algorithm-II (NSGA-II) is an evolutionary algorithm that does not require derivative differentiation and is capable of population search. In this study, a nuclear power plant accident optimization strategy is developed using the Modular Accident Analysis Program (MAAP) in conjunction with NSGA-II. The strategy enables decision makers to consider multiple mitigation objectives in a complex decision environment. Focusing on the CPR1000, this study applies the optimization strategy to automatically search for optimal mitigation strategies for small break loss of coolant accident (SBLOCA) and station blackout hot leg creep rupture accidents (SBOHLCR). Comparing the optimization results with the basic accident sequence, it is found that the reactor pressure vessel (RPV) failure time is delayed from 72,702 s to 128,730 s under SBLOCA and from 23,828 s to 28,363 s under SBOHLCR. This study has also verified that the optimal SAM strategy obtained by the strategy through dual objective optimization has better mitigation effects than a strategy that only considers one objective. This optimization strategy has the potential to be applied to other types of severe accident management studies in the future.","PeriodicalId":17787,"journal":{"name":"Kerntechnik","volume":" 71","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135340470","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Advances in triple tube heat exchangers regarding heat transfer characteristics of single and two-phase flows in comparison to double tube heat exchangers part 1 三管换热器单相和两相流换热特性与双管换热器的比较研究进展。第1部分

4区工程技术

Kerntechnik Pub Date : 2023-10-30 DOI: 10.1515/kern-2023-0023

Dogan Akgul, Hatice Mercan, Ozgen Acikgoz, Ahmet Selim Dalkilic

{"title":"Advances in triple tube heat exchangers regarding heat transfer characteristics of single and two-phase flows in comparison to double tube heat exchangers part 1","authors":"Dogan Akgul, Hatice Mercan, Ozgen Acikgoz, Ahmet Selim Dalkilic","doi":"10.1515/kern-2023-0023","DOIUrl":"https://doi.org/10.1515/kern-2023-0023","url":null,"abstract":"Abstract Triple concentric-tube heat exchangers are used widely in refrigeration, drying, energy storage, chemical systems, and the food industry. To handle excessive temperature differences, the heat transfer area, as an option, the heat exchanger’s length, is necessary to be increased. Triple tubes have a significant advantage in this regard in comparison to double ones. The target of this review is to discuss the most recent publications, including the single-phase flows in these heat exchangers, focusing on the heat transfer and hydrodynamic characteristics, and to classify them with various contemporary aspects. The operating conditions, enhanced surfaces, and sizes, as well as the geometrical parameters, are categorized as being part of experimental, numerical, and analytical research. The studies indicate that the heat transfer characteristics of triple concentric-tube heat exchangers are better than those of double tube heat exchangers. In single-phase studies, the convective and overall heat transfer coefficients, Nusselt number, heat transfer rate, and effectiveness are greater in triple heat exchangers than in double heat exchangers, and the heat exchanger length required to achieve the same heat transfer performance is shorter in triple heat exchangers than in double heat exchangers. Heat transfer surface area increases by adding a concentric third tube. Advanced surfaces enhance heat transfer compared to smooth surfaces and flow turbulence in comparison to smooth surfaces. Heat transfer from triple-one enhanced surfaces is not well-analyzed. Design and use of triple ones as a double one’s alternative should advance shortly.","PeriodicalId":17787,"journal":{"name":"Kerntechnik","volume":"41 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136019558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Advances in triple tube heat exchangers regarding heat transfer characteristics of single and two-phase flows in comparison to double tube heat exchangers part 2 三管换热器单相和两相流换热特性与双管换热器的比较研究进展。第二部分

4区工程技术

Kerntechnik Pub Date : 2023-10-30 DOI: 10.1515/kern-2023-0108

Dogan Akgul, Hatice Mercan, Ozgen Acikgoz, Ahmet Selim Dalkilic

{"title":"Advances in triple tube heat exchangers regarding heat transfer characteristics of single and two-phase flows in comparison to double tube heat exchangers part 2","authors":"Dogan Akgul, Hatice Mercan, Ozgen Acikgoz, Ahmet Selim Dalkilic","doi":"10.1515/kern-2023-0108","DOIUrl":"https://doi.org/10.1515/kern-2023-0108","url":null,"abstract":"Abstract Triple concentric-tube heat exchangers are often used in a variety of industries, including HVAC, food and beverage manufacturing, and chemical processing. They may also be utilized in applications requiring thermal homogeneity, such as food and pharmaceutical production. They are appropriate for a number of applications since they may be constructed to withstand a range of temperatures and pressures. The purpose of this study is to examine the most current papers, covering single- and two-phase flows having pure and nanofluids with a particular emphasis on the heat transfer and hydrodynamic properties. The use of advanced surfaces improves heat transfer with respect to smooth surfaces, and the use of nanofluids has a positive influence on heat transfer characteristics with the increase in nanoparticle volume concentration since nanoparticles rise thermal conductivity, heat transfer area, and Brownian motion. The practical calculation methodologies, proposed correlations for calculating the Nusselt number and friction factor in triple ones are shown. There are insufficient studies to comment on pressure drop features, and correlations for Nusselt numbers and friction factors that are only known for single-phase flows. The research indicates that the heat transfer characteristics of triple concentric-tube heat exchangers surpass those of double tube heat exchangers. Important progress is supposed to occur for the design and utilization of triple ones as a substitute for double ones soon. Finally, there are a limited number of experimental two-phase flow studies in triple ones. It is essential to work on this topic to meet the important lack in open sources.","PeriodicalId":17787,"journal":{"name":"Kerntechnik","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136018761","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A non-dominated discrete differential evolution for fuel loading pattern optimization of a nuclear research reactor 核研究堆燃料装载模式优化的非支配离散微分演化

4区工程技术

Kerntechnik Pub Date : 2023-10-09 DOI: 10.1515/kern-2023-0043

Quang Binh Do

引用次数: 0

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