Case Studies in Thermal Engineering最新文献_第5页

Energy, exergy, and advanced exergy analysis of a novel solar-based S-CO2 cycle and comparison of systems with different layouts

IF 6.8 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2024-12-06 DOI: 10.1016/j.csite.2024.105612

Qiujie Cheng, Yunlong Zhou, Mei Yang, Xinrui Han, Jiani Liu

{"title":"Energy, exergy, and advanced exergy analysis of a novel solar-based S-CO2 cycle and comparison of systems with different layouts","authors":"Qiujie Cheng, Yunlong Zhou, Mei Yang, Xinrui Han, Jiani Liu","doi":"10.1016/j.csite.2024.105612","DOIUrl":"https://doi.org/10.1016/j.csite.2024.105612","url":null,"abstract":"Solar energy is an endless source of renewable energy, so solar-powered S-CO<ce:inf loc=\"post\">2</ce:inf> cycle power generation systems have received much attention from scholars. In this research, a new S-CO<ce:inf loc=\"post\">2</ce:inf> cycle layout based on a recompression cycle and an intercooling cycle is proposed, and the thermal performance of the three layouts is compared and analyzed. Percentage exergy loss of each component in the system is obtained by conventional exergy analysis and further advanced exergy analysis is used to explore the enhancement possibilities of each component and their interactions. The investigation results revealed that the recompression cycle, intercooling cycle and combined cycle had respective evaluations of 38.45 %, 39.775 and 42.05 % efficiency. Sensitivity analysis revealed that the provided cycle has superior efficiency at higher turbine inlet parameters. The conventional exergy analysis and advanced exergy analysis yielded a combined cycle HE1 exergy loss of 8.27 MW and an avoidable exergy loss of 4.70 MW, with a high potential for improvement. This study provides directions for the structural optimization of solar-driven S-CO<ce:inf loc=\"post\">2</ce:inf> cycle power generation systems.","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"200 1","pages":""},"PeriodicalIF":6.8,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142815812","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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

Enviroeconomic optimization of insulation thickness for building exterior walls through thermoeconomic and life cycle assessment analysis

IF 6.8 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2024-12-06 DOI: 10.1016/j.csite.2024.105606

Mehmet Kadri Akyüz

{"title":"Enviroeconomic optimization of insulation thickness for building exterior walls through thermoeconomic and life cycle assessment analysis","authors":"Mehmet Kadri Akyüz","doi":"10.1016/j.csite.2024.105606","DOIUrl":"https://doi.org/10.1016/j.csite.2024.105606","url":null,"abstract":"The economic optimum insulation thicknesses (OIT) for heated buildings in five different climate regions in Turkiye were determined, and the energy, cost, and life cycle-based environmental performances were analyzed. Calculations were performed using three different fuels (natural gas, fuel oil, and coal) and four different insulation materials: expanded polystyrene (EPS), rock wool (RW), glass wool (GW), and extruded polystyrene (XPS). This study utilized a thermoeconomic approach to evaluate energy and economic performance and a life cycle assessment (LCA) approach to assess environmental impacts, ensuring a comprehensive analysis of insulation strategies. The impacts of climate change factors were expressed as kg CO<ce:inf loc=\"post\">2</ce:inf> equivalent (kgCO<ce:inf loc=\"post\">2</ce:inf>eq) using 100-years global warming potential (GWP). The annual energy savings varying from 18.41 to 258.15 kWh/(year.m<ce:sup loc=\"post\">2</ce:sup>) for the warmer and the colder climate zones, respectively. The maximum avoided environmental impact (AEI) due to energy saved from thermal insulation was 144.11 kgCO<ce:inf loc=\"post\">2</ce:inf>eq/(year.m<ce:sup loc=\"post\">2</ce:sup>) for coal and RW in coldest climate zone, while the minimum AEI was 5.31 kgCO<ce:inf loc=\"post\">2</ce:inf>eq/(year.m<ce:sup loc=\"post\">2</ce:sup>) for natural gas and XPS in warmest climate zone. Among insulation materials, EPS offers the shortest environmental payback period, whereas RW requires the longest, highlighting material-specific trade-offs. In all climate zones, environmental payback periods are much shorter than economic ones.","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"5 1","pages":""},"PeriodicalIF":6.8,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142815810","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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

Corrigendum to “Significance of heat transfer in a reversible esterification of Arrhenius activation energy with partial slip” [Case Stud. Therm. Eng. 64 (2024) 105316] 部分滑移的阿伦尼乌斯活化能可逆酯化中热量传递的意义"[案例研究.热力工程.64 (2024) 105316] 更正

IF 6.8 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2024-12-06 DOI: 10.1016/j.csite.2024.105608

R. Umadevi, D. Arivukkodi, Sultan Alshehery, Ilyas Khan

引用次数: 0

Thermal, flow and inclusions analysis of clogging mechanism in continuous casting process 连铸过程中堵塞机理的热分析、流动分析和夹杂物分析

IF 6.8 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2024-12-04 DOI: 10.1016/j.csite.2024.105602

Xiaocheng Liang, Lin Wang, Zhongfei Liu, Zhihui Li, Xudong Luo, Feng Wu, Qichen Yuan, Benjun Cheng

引用次数: 0

Numerical study of heat transfer and fluid flow in a symmetric wavy microchannel heat sink reinforced by slanted secondary channels

IF 6.8 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2024-12-04 DOI: 10.1016/j.csite.2024.105605

Qifeng Zhu, Xianyao Liu, Jingwei Zeng, He Zhao, Wenqiang He, Haoxin Deng, Guoyan Chen

{"title":"Numerical study of heat transfer and fluid flow in a symmetric wavy microchannel heat sink reinforced by slanted secondary channels","authors":"Qifeng Zhu, Xianyao Liu, Jingwei Zeng, He Zhao, Wenqiang He, Haoxin Deng, Guoyan Chen","doi":"10.1016/j.csite.2024.105605","DOIUrl":"https://doi.org/10.1016/j.csite.2024.105605","url":null,"abstract":"To improve the thermal and hydraulic performance of symmetric wavy microchannel heat sinks, a novel design has been devised with slanted secondary channels from trough to crest based on its pressure distribution characteristics. These channels connect regions of adverse pressure gradient in any two neighboring channels to form a novel microchannel heat sink (SW-TC). Employing three-dimensional numerical simulations, a comparative analysis was performed on the flow and heat transfer characteristics among the SW-TC, the symmetric wavy microchannel with wave crest-to-crest secondary flow channels (SW-CC), and the symmetric wavy microchannel with wave trough-to-trough secondary channels (SW-TT). The results indicate that the design of slanted secondary channels significantly improves fluid mixing across channels, suppresses boundary layer development, and consequently enhances the heat transfer efficiency and overall performance of the SW-TC. The SW-TC achieves its peak relative Nusselt number and overall performance factor at 1.835 and 1.843, respectively. Furthermore, the SW-TC exhibits excellent temperature uniformity across the heating wall, and its temperature increase along the flow direction is a mere 8.3 K at Re = 200. It also presents the lowest entropy generation number among all designs, reaching 0.56 at Re = 100.","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"39 1","pages":""},"PeriodicalIF":6.8,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142815813","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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

Experimental and numerical investigations of cavity flame spread in double skin façade

IF 6.8 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2024-12-04 DOI: 10.1016/j.csite.2024.105607

Xukun Sun, Hideki Yoshioka, Takafumi Noguchi, Yuhei Nishio, Biao Zhou

{"title":"Experimental and numerical investigations of cavity flame spread in double skin façade","authors":"Xukun Sun, Hideki Yoshioka, Takafumi Noguchi, Yuhei Nishio, Biao Zhou","doi":"10.1016/j.csite.2024.105607","DOIUrl":"https://doi.org/10.1016/j.csite.2024.105607","url":null,"abstract":"In recent decades, double-skin façades (DSFs) have gained popularity in modern commercial buildings. However, their cavities can potentially accelerate flame spread, raising significant concerns regarding façade fire safety. Given that existing studies focus on the DSF component failures and fire stop measures without modeling validation, this study presents real-scale DSF fire experiments and modeling in accordance with JIS A 1310, conducted without combustibles to clarify fire behaviors within the cavity. The experiments employ HRRs of 600–900 kW and cavity depths of 0.4 and 0.8 m, highlighting that flame attachment to the facing wall is dependent on HRRs rather than cavity depths. Subsequently, Computational Fluid Dynamics (CFD) is utilized to investigate DSF fires, with validation against experimental temperature distribution and flame morphology. Furthermore, the validated CFD modeling is applied to scenarios with extended cavity depths and varied opening shapes, indicating that a cavity depth of ≥0.7 m mitigates flame spread for an opening ratio of n ≥ 1. The Modified-McCaffrey-Yokoi (MMY) model is proposed to characterize façade flame temperatures across varied cavity depths, and its convergence, featured by opening shapes and HRRs, is categorized to distinguish cavity flame behavior.","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"10 1","pages":""},"PeriodicalIF":6.8,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142815811","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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

Comprehensive analysis and optimization of an efficient combined power and refrigeration cycle suitable for recovering low/mid-grade waste flue gas 全面分析和优化适用于回收中低品位废烟气的高效发电和制冷联合循环系统

IF 6.8 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2024-12-04 DOI: 10.1016/j.csite.2024.105587

Shaobo Zhang, Shixuan Wang, Jiafeng Wu

{"title":"Comprehensive analysis and optimization of an efficient combined power and refrigeration cycle suitable for recovering low/mid-grade waste flue gas","authors":"Shaobo Zhang, Shixuan Wang, Jiafeng Wu","doi":"10.1016/j.csite.2024.105587","DOIUrl":"https://doi.org/10.1016/j.csite.2024.105587","url":null,"abstract":"To effectively recover low/mid-grade waste flue gas and provide larger refrigeration capacity, an efficient combined power and refrigeration cycle only using ammonia water as the working fluid is proposed and studied in this paper. Parametric analysis is conducted from the perspectives of thermodynamics, exergoeconomics, and environment, the results demonstrate that the low/mid-grade waste flue gas within a wide temperature range can be sufficiently recovered by the proposed cycle, and the cycle performance is significantly affected by the turbine inlet pressure, work/basic concentration and separation temperature of work solution. Based on the heat source condition of 300 °C/10 kg·s<ce:sup loc=\"post\">−1</ce:sup>, the results of single-objective optimization show that the maximum effective exergy efficiency, reduction amount of CO<ce:inf loc=\"post\">2</ce:inf> emission and waste heat recovery ratio that can be achieved are 0.5989, 262 kg/h and 0.97 respectively, and the achievable minimum unit cost of produced exergy is 8.432 $·GJ<ce:sup loc=\"post\">−1</ce:sup>. Besides, the multi-objective optimization indicates that the optimal comprehensive thermodynamic efficiency is 0.5458 with net power output of 372.5 kW and larger refrigeration capacity of 545.7 kW, and the associated effective exergy efficiency, unit cost of produced exergy, reduction amount of CO<ce:inf loc=\"post\">2</ce:inf> emission and waste heat recovery ratio are 0.5701, 9.187 $/GJ, 258.3 kg/h and 0.9574, respectively.","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"3 1","pages":""},"PeriodicalIF":6.8,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142815815","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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

Thermal effects of ternary Casson nanofluid flow over a stretching sheet: An investigation of Thomson and Troian velocity slip

IF 6.8 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2024-12-03 DOI: 10.1016/j.csite.2024.105561

Musharafa Saleem, A. Al-Zubaidi, Neyara Radwan, S. Saleem, Hind Adawi

{"title":"Thermal effects of ternary Casson nanofluid flow over a stretching sheet: An investigation of Thomson and Troian velocity slip","authors":"Musharafa Saleem, A. Al-Zubaidi, Neyara Radwan, S. Saleem, Hind Adawi","doi":"10.1016/j.csite.2024.105561","DOIUrl":"https://doi.org/10.1016/j.csite.2024.105561","url":null,"abstract":"The present research analyzes the properties of a Casson ternary nanofluid over a stretching sheet with Thomson and Troian slip conditions, taking into consideration the influences of electromagnetohydrodynamic (EMHD). The ternary nanofluid comprises three different nanoparticles, which include titanium dioxide (TiO<ce:inf loc=\"post\">2</ce:inf>), copper (Cu), and silver (Ag), all being suspended in oil, which is the base fluid. They are involved because of their good thermal conductivity and chemical stability, and Ag<ce:glyph name=\"sbnd\"></ce:glyph>Cu<ce:glyph name=\"sbnd\"></ce:glyph>TiO<ce:inf loc=\"post\">2</ce:inf> /Oil nanofluid is a composite of copper, titanium oxide, and oil. Hence, carrying out the said procedure, the ternary nanofluid becomes Ag<ce:glyph name=\"sbnd\"></ce:glyph>Cu<ce:glyph name=\"sbnd\"></ce:glyph>TiO<mml:math altimg=\"si1.svg\" display=\"inline\"><mml:msub><mml:mrow></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:math>/Oil. The sheet is, however, thought to be stretching vertically while the flow is determined by the effect of the gravity force through the free convention. Moreover, the phenomena of EMHD, porous medium, thermal slip, thermal radiation, Joule heating, and heat source/sink are included to make the energy equation more real-life. This leads to a set of partial differential equations (PDEs) based mathematical models transformed into ordinary differential equations (ODEs)-appropriate similarity transformation. The Runge–Kutta–Fehlberg (RKF-45) method solves the given ordinary differential system. According to the research’s findings, the temperature of the ternary Casson nanofluid rises when the suspension of silver, copper, and titanium dioxide nanoparticles increases, and the velocity of flow for merely silver and copper decreases when the density decreases. This causes the flow rate to be constricted through the velocity slip condition, at the same time as the nanofluid’s temperature increases.","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"16 1","pages":""},"PeriodicalIF":6.8,"publicationDate":"2024-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142777473","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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

Interpretable machine learning modeling of temperature rise in a medium voltage switchgear using multiphysics CFD analysis

IF 6.8 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2024-12-03 DOI: 10.1016/j.csite.2024.105585

Mahmood Matin, Amir Dehghanian, Amir Hossein Zeinaddini, Hossein Darijani

{"title":"Interpretable machine learning modeling of temperature rise in a medium voltage switchgear using multiphysics CFD analysis","authors":"Mahmood Matin, Amir Dehghanian, Amir Hossein Zeinaddini, Hossein Darijani","doi":"10.1016/j.csite.2024.105585","DOIUrl":"https://doi.org/10.1016/j.csite.2024.105585","url":null,"abstract":"In recent decades, leading companies and research groups have extensively conducted Multiphysics computational fluid dynamics (CFD) analyses to evaluate temperature rise in switchgear systems, aiming to meet type-testing requirements specified in IEC standards. However, the complex interaction of geometrical and operational parameters presents significant challenges in interpreting these methods. Artificial intelligence (AI) algorithms have gained attention in various engineering fields to address similar issues. This paper investigates the influence of four key manufacturing and operational parameters, both categorical and continuous, on temperature rise in a medium voltage (MV) switchgear case study. A CFD-based dataset was created from these parameters to target maximum temperature, facilitating the study's objective. Several models for temperature rise estimation, including extreme gradient boosting (XGBoost), support vector regression, decision tree, and random forest, were compared. An explainable artificial intelligence (XAI) technique, Shapley Additive Explanations (SHAP)<ce:bold>,</ce:bold> was applied to the best-performing model to evaluate the importance of each feature in predicting maximum temperature<ce:bold>.</ce:bold> The results revealed that XGBoost provided the most accurate predictions, with a scatter band (SB) of ±1.01 and average R<ce:sup loc=\"post\">2</ce:sup> values of 99.98 % and 96.59 % for the training and testing sets, respectively. SHAP analysis identified the most significant variables affecting temperature prediction as current, air velocity, duct area, and switchgear conditions, in that order<ce:bold>.</ce:bold>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"6 1","pages":""},"PeriodicalIF":6.8,"publicationDate":"2024-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142777466","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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

Asphyxiation effect analysis in confined space of B-type oil pool fire under pressure changes of nitrogen extinguishing system 氮气灭火系统压力变化下 B 型油池火灾密闭空间的窒息效应分析

IF 6.8 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2024-12-03 DOI: 10.1016/j.csite.2024.105598

Feiyue Wang, Weixuan Li, Litian Wan, Long Yan, Zhisheng Xu

{"title":"Asphyxiation effect analysis in confined space of B-type oil pool fire under pressure changes of nitrogen extinguishing system","authors":"Feiyue Wang, Weixuan Li, Litian Wan, Long Yan, Zhisheng Xu","doi":"10.1016/j.csite.2024.105598","DOIUrl":"https://doi.org/10.1016/j.csite.2024.105598","url":null,"abstract":"Nitrogen fire extinguishing system has a significant development space in the modern fire extinguishing because of its environmental protection, energy saving and high stability. To further broaden the application field of nitrogen fire extinguishing system, a shrinkage size model was used as the research object and combined with simulated flow field analysis. A nitrogen fire extinguishing system was characterized for alcohol fire extinguishing efficacy using nitrogen injection pressure as a variable and parameters such as extinguishing time, oxygen concentration, and temperature. Furthermore, diesel and gasoline were used as combustible materials to verify the extinguishing efficacy of pressure variation on Class B oil pool fires. It was found that with the increase of nitrogen injection pressure, the nitrogen extinguishing efficacy gradually increased and then leveled off in the confined space. The asphyxiating oxygen concentrations were 12.2 %, 13.2 % and 13.7 % for ethanol, diesel and gasoline, respectively. Asphyxiating oxygen concentration above limiting oxygen concentration (LOC). For extinguishing Class B oil pool fires in confined spaces, nitrogen extinguishing systems showed excellent fire extinguishing efficiency. They had specific application prospects in the field of protecting underground oil storage tanks and oil wells.","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"44 1","pages":""},"PeriodicalIF":6.8,"publicationDate":"2024-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142815817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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