Case Studies in Thermal Engineering最新文献_第6页

Computational and experimental investigation of thermoelectric generators in series-parallel configurations under variable resistive loads and temperature gradients 变电阻负载和温度梯度下热电发电机串并联配置的计算与实验研究

IF 6.4 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2026-04-01 Epub Date: 2026-03-05 DOI: 10.1016/j.csite.2026.107913

Roshan Manghwar , Jeyraj Selvaraj , Hafeez Khoharo , Laveet Kumar , Muhammad Shakeel Ahmad

{"title":"Computational and experimental investigation of thermoelectric generators in series-parallel configurations under variable resistive loads and temperature gradients","authors":"Roshan Manghwar , Jeyraj Selvaraj , Hafeez Khoharo , Laveet Kumar , Muhammad Shakeel Ahmad","doi":"10.1016/j.csite.2026.107913","DOIUrl":"10.1016/j.csite.2026.107913","url":null,"abstract":"<div><div>Thermoelectric generation is a potential technology for waste heat recovery, however, increase in the internal resistance is one of the key parameters limiting its utilization for scalable applications. Previous research in this domain is limited to the thermoelectric elements and modules. Current research focuses on the performance evaluation of thermoelectric generators under variable resistive loads and temperature gradients in different configurations. Computational modelling of the thermoelectric generator has been performed using fully coupled steady-state model in conjunction with experimental research to validate the results. Results were acquired under varying temperature gradients and resistive loads between 1Ω and 30Ω and extended up to 40Ω for eight modules in series. The system is analyzed experimentally through natural convective cooling for variable resistive load maintained at constant temperature, and the reverse scenario is also considered. The maximum power generated from a single thermoelectric module is 1.69W at 5Ω resistive load. This value corresponds to the temperature difference of 100 °C and surpasses the experimental value by 6.29%. The study computationally evaluates thermoelectric performance of two, four, and eight modules in both series and parallel arrangements. The power output for eight modules configured in series, parallel, and hybrid arrangement was measured as 13.53W, 12.60W, and 13.55W, respectively, and efficiency was determined as 3.79%, 3.77%, and 3.84% respectively. The comparative results highlight optimal performance of thermoelectric generators in series & parallel hybrid arrangement. Study represents low grade waste heat recovery potential from coal fired power plants and oil and gas sector.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"80 ","pages":"Article 107913"},"PeriodicalIF":6.4,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147387426","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

Numerical optimization by deep single selective investigation and experimental validation for star-fin inserts in absorber tubes 吸收体管中星翅片插片的深度单选择数值优化及实验验证

IF 6.4 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2026-04-01 Epub Date: 2026-03-10 DOI: 10.1016/j.csite.2026.107930

Zeki Ali Al-Saadi , Adnan Ibrahim , Firas Abdulamir Radhi , Yassine El Alami , Anwer B. Al-Aasam , Rasha Abdulrazzak Jasim , Sharul Sham Dol , Mohammed Ghazal , Ahmad Fazlizan

{"title":"Numerical optimization by deep single selective investigation and experimental validation for star-fin inserts in absorber tubes","authors":"Zeki Ali Al-Saadi , Adnan Ibrahim , Firas Abdulamir Radhi , Yassine El Alami , Anwer B. Al-Aasam , Rasha Abdulrazzak Jasim , Sharul Sham Dol , Mohammed Ghazal , Ahmad Fazlizan","doi":"10.1016/j.csite.2026.107930","DOIUrl":"10.1016/j.csite.2026.107930","url":null,"abstract":"<div><div>Limited thermal efficiency remains a persistent challenge in the design of modern heat exchangers employing absorber tubes. This study addresses this limitation by integrating geometric fin optimization with nanofluid enhancement to maximize the thermal-hydraulic performance factor (THPF). A novel star-finned copper absorber tube was designed for turbulent flow conditions. The optimization was carried out using the Deep Single-Selective Investigation (DSSI) methodology, considering five key geometric parameters: fin edge number (2-5), fin diameter (14-15.5 mm), fin thickness (2-3.5 mm), number of fins per rod (4-8), and angular spacing (0-40°). The analysis was conducted under hydraulic and geometric constraints, with Reynolds numbers ranging from 6000 to 15,000 and a fixed absorber tube diameter of 19.10 mm. The optimal configuration consisted of a five-edge fin with a 15.5 mm diameter, six fins per rod, a thickness of 3 mm, and an angular spacing of 30°. Numerical results showed THPF values of 1.856 with distilled water and 2.100 with the 0.2% Al<sub>2</sub>O<sub>3</sub> nanofluid, demonstrating the enhanced THPF compared with a smooth tube baseline. Experimental validation yielded THPF values of 1.834 with distilled water and 2.004 with the nanofluid. CFD predictions matched experiments (R<sup>2</sup> = 0.9982, RMSE = 2.42), confirming the robustness of the framework and supporting the applicability of the proposed design for advanced thermal systems.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"80 ","pages":"Article 107930"},"PeriodicalIF":6.4,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147387428","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

Assessment of fire flow demand in Chinese traditional villages based on UAV photogrammetry and fire propagation analysis 基于无人机摄影测量与火灾传播分析的中国传统村落消防流量需求评估

IF 6.4 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2026-04-01 Epub Date: 2026-02-20 DOI: 10.1016/j.csite.2026.107841

Feiyang Zheng, Zhigang Song, Jian Zhang, Jinsheng Han

{"title":"Assessment of fire flow demand in Chinese traditional villages based on UAV photogrammetry and fire propagation analysis","authors":"Feiyang Zheng, Zhigang Song, Jian Zhang, Jinsheng Han","doi":"10.1016/j.csite.2026.107841","DOIUrl":"10.1016/j.csite.2026.107841","url":null,"abstract":"<div><div>Chinese traditional villages are generally exposed to severe risks of fire propagation. Against this background, the scientific and rational estimation of fire flow demand is not only a key basis for evaluating whether existing water-supply conditions can meet firefighting requirements but also a prerequisite for developing effective suppression and protection strategies. This study develops an efficient and cost-effective framework for assessing fire flow demand in traditional villages. First, unmanned aerial vehicle (UAV) oblique photogrammetry combined with on-site surveys was used to obtain the external parameters and internal features of buildings, which were then used to identify fire propagation pathways between buildings. Then, the fire flow demand for each building was calculated individually, distinguishing between offensive operations (extinguishing the fire source) and defensive operations (protecting adjacent buildings). The resulting distribution of fire flow demand across buildings was used to estimate the total fire flow demand of the village. Finally, the proposed framework was applied to calculate the fire flow demand of eleven representative traditional villages in Yunnan Province, followed by a comparison with current codes. The comparison reveals that the design flow rates of existing integrated water-supply systems are insufficient to meet the firefighting needs of traditional villages fully. Furthermore, correlation analysis reveals that offensive fire flow demand is primarily influenced by building volume, whereas defensive fire flow demand is associated with spatial connectivity and separation distance.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"80 ","pages":"Article 107841"},"PeriodicalIF":6.4,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146777431","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

Lightweight concrete with improved thermomechanical properties incorporating PCM-infused microsilica additives 轻质混凝土与改进的热机械性能，加入pcm注入微二氧化硅添加剂

IF 6.4 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2026-04-01 Epub Date: 2026-02-19 DOI: 10.1016/j.csite.2026.107837

Mahshid Abdoli, Davood Mostofinejad, Amin Karimi, Alireza Saljoughian, Mohammadreza Eftekhar

{"title":"Lightweight concrete with improved thermomechanical properties incorporating PCM-infused microsilica additives","authors":"Mahshid Abdoli, Davood Mostofinejad, Amin Karimi, Alireza Saljoughian, Mohammadreza Eftekhar","doi":"10.1016/j.csite.2026.107837","DOIUrl":"10.1016/j.csite.2026.107837","url":null,"abstract":"<div><div>The increasing need for environmentally sustainable building materials has positioned lightweight concrete (LWC) as a promising solution, offering benefits such as reduced weight and improved thermal and acoustic properties. However, previous studies indicate that incorporating lightweight aggregates (LWA) into LWC can adversely affect the material's mechanical properties. Furthermore, the potential integration of phase-change materials (PCMs) in LWC remains largely unexplored, particularly under challenging environmental conditions. To address these gaps, this study investigates the controlled use of lightweight expanded clay aggregate (LECA) and micro-silica infused with polyethylene glycol (PEG) 600 and 1000 as PCMs to develop LWC with superior mechanical and thermal properties. A novel “simulated solar exposure and moisture conditioning test” and a thermal behavior evaluation test are introduced. Additional mechanical and thermal tests, including measurements of compressive strength and thermal conductivity, were conducted to optimize LWC properties for warm, humid climates. The results indicate that, although water absorption increased with higher LECA contents, PEG 1000 reduced it by 67%. Thermal conductivity decreased with increasing LECA content and further decreased with PEG 1000 infusion, achieving a 64% reduction. The sunlight and humidity simulation test also demonstrated the superior thermal stability of PEG 1000-infused mixtures. These findings highlight the potential of PCM-integrated LWC to enhance energy efficiency and thermal performance, offering significant advancements for sustainable building design.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"80 ","pages":"Article 107837"},"PeriodicalIF":6.4,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146778093","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

Numerical simulation on flow regulation and heat transfer characteristics of embedded adaptive pin-fin microchannel heat sinks under non-uniform heat sources 非均匀热源下嵌入式自适应Pin-Fin微通道散热器流动调节与传热特性数值模拟

IF 6.4 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2026-04-01 Epub Date: 2026-02-20 DOI: 10.1016/j.csite.2026.107847

Linzheng Fu, Jing Wen, Yiou Qiu, Ping Wu, Liancheng Wang, Wenhui Zhu

{"title":"Numerical simulation on flow regulation and heat transfer characteristics of embedded adaptive pin-fin microchannel heat sinks under non-uniform heat sources","authors":"Linzheng Fu, Jing Wen, Yiou Qiu, Ping Wu, Liancheng Wang, Wenhui Zhu","doi":"10.1016/j.csite.2026.107847","DOIUrl":"10.1016/j.csite.2026.107847","url":null,"abstract":"<div><div>This work proposes an adaptive pin-fin microchannel cooling configuration that employs the thermally responsive deformation of hydrogel pin-fins to manage the transient and spatially uneven thermal loads generated during chip operation. Temperature-driven volumetric changes in the hydrogel structures enable continuous adjustments of coolant passage geometry, allowing the system to redistribute flow locally and achieve self-regulating thermal control. A dynamic-mesh numerical approach is developed to characterize pin-fin deformation under high heat-flux conditions and to evaluate its impact on flow behavior and heat dissipation. Compared with non-adaptive microchannel heat sink (N-MCHS), the adaptive design (A-MCHS) demonstrates distinctly improved coolant routing and enhanced thermal performance. Under a single-hotspot condition with a heat flux of 100 W/cm<sup>2</sup>, the A-MCHS lowers the peak hotspot temperature by 7.5 K and reduces the pressure drop by 44.4%, while requiring only 2.26 mW of pumping power. The corresponding Nusselt numbers (<em>Nu</em>) for A-MCHS and N-MCHS are 7.36 and 5.68, respectively, confirming the superior heat transfer capability and low energy demand of the adaptive configuration. The system also maintains effective temperature suppression when multiple hotspots are present. Additionally, as the Reynolds number (<em>Re</em>) increases, the A-MCHS consistently achieves lower hotspot temperatures and reduced thermal non-uniformity relative to the N-MCHS, highlighting its stable thermal regulation behavior. Overall, the proposed adaptive microchannel structure provides a promising route toward efficient, low-power, and self-adjusting cooling solutions for chips operating under dynamically evolving heat flux conditions.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"80 ","pages":"Article 107847"},"PeriodicalIF":6.4,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146778512","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

Enhanced conventional solar still performance with water unit, vertical wick system, and PCM-Ag nano integration 提高传统太阳能蒸馏器性能与水单元，垂直灯芯系统，和PCM-Ag纳米集成

IF 6.4 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2026-04-01 Epub Date: 2026-02-28 DOI: 10.1016/j.csite.2026.107877

Hisham M. Almongy , I. Elbatal , A.E. Kabeel , Wissam H. Alawee , Z.M. Omara , Fadl A. Essa , T.E.M. Atteya , Samah M. Elkholy

{"title":"Enhanced conventional solar still performance with water unit, vertical wick system, and PCM-Ag nano integration","authors":"Hisham M. Almongy , I. Elbatal , A.E. Kabeel , Wissam H. Alawee , Z.M. Omara , Fadl A. Essa , T.E.M. Atteya , Samah M. Elkholy","doi":"10.1016/j.csite.2026.107877","DOIUrl":"10.1016/j.csite.2026.107877","url":null,"abstract":"<div><div>Solar distillation represents a sustainable solution for freshwater production in water-scarce regions. However, conventional solar stills (CSS) face significant limitations including low productivity rates, substantial heat losses through rear walls, and inefficient utilization of solar radiation. The study integrates three modifications: (1) a water unit (WU) for heat loss reduction, (2) a vertical wick solar still (VWSS) for hot water feeding, and (3) PCM enhanced with silver nanoparticles for thermal storage. The integrated system CSS + WU + VWSS + PCM-Ag was tested against conventional CSS. Results demonstrated that the fully integrated system (CWCSS + WU + VWSS with PCM-Ag) achieved cumulative daily productivity of 13,250 mL/m<sup>2</sup>, representing a 327% improvement over conventional solar stills producing 3100 mL/m<sup>2</sup>. The modified system also reduced the cost of distilled water from 0.024 $/L to 0.013 $/L. These findings confirm that integrated modifications combining heat loss reduction, hot water feeding, and thermal storage substantially enhance solar still performance while maintaining economic viability. The study recommends further optimization of nano-enhanced PCM configurations and extended testing under varying climatic conditions.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"80 ","pages":"Article 107877"},"PeriodicalIF":6.4,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147330302","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

Effect of air inlet angle variation on the efficiency of hydrogen-powered Stirling engines 进气角度变化对氢动力斯特林发动机效率的影响

IF 6.4 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2026-04-01 Epub Date: 2026-02-16 DOI: 10.1016/j.csite.2026.107830

Heba Alzaben , Ahmad Aljabr , S.A. Marzouk , Saad Alshammari , Dame Ayane

{"title":"Effect of air inlet angle variation on the efficiency of hydrogen-powered Stirling engines","authors":"Heba Alzaben , Ahmad Aljabr , S.A. Marzouk , Saad Alshammari , Dame Ayane","doi":"10.1016/j.csite.2026.107830","DOIUrl":"10.1016/j.csite.2026.107830","url":null,"abstract":"<div><div>Stirling engines are significant for their high efficiency, low emissions, and capability to use various heat sources for renewable energy systems, waste heat recovery, and applications where low maintenance is crucial. Hydrogen-powered Stirling engines combine the high efficiency of Stirling engines with the clean-burning nature of hydrogen fuel. This study introduces a new approach by optimizing the air inlet angle in a hydrogen-fueled Stirling engine using CFD simulations. The effects of air inlet angle variation (60°, 90°, and 120°) on the performance of a hydrogen-fueled Stirling engine are studied. Unlike prior studies focusing on fuel type or scale, this work highlights the effects of inlet geometry on inducing combustion dynamics, thermal behavior, and engine performance. The parameters such as power output, thermal efficiency, hydrogen mass fraction, velocity, peak temperature, and flow organization are examined. Results show that the 90° air inlet angle offers the best performance, improving thermal efficiency and power output by 15% and 17.6%, respectively, compared to the 60° angle case, and by 12% and 11% compared to the 120° angle configuration. Enhanced performance is attributed to improved mixing, more complete hydrogen combustion, and a 28% increase in peak temperature. In contrast, the 60° case causes less efficient flow patterns and delayed combustion. These insights present a valuable framework for optimizing inlet angle design in hydrogen-fueled Stirling engines, advancing their potential for sustainable energy applications.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"80 ","pages":"Article 107830"},"PeriodicalIF":6.4,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147330152","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

Enhancement of convective heat transfer in Taylor-Couette flow with elliptical slits using machine learning and particle swarm optimization 基于机器学习和粒子群优化的椭圆狭缝Taylor-Couette流对流换热增强

IF 6.4 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2026-04-01 Epub Date: 2026-02-21 DOI: 10.1016/j.csite.2026.107848

Huan-Yi Ren , Si-Liang Sun , Dong Liu , Muhammad Bilal Riaz , Y.S. Hamed , Afraz Hussain Majeed

{"title":"Enhancement of convective heat transfer in Taylor-Couette flow with elliptical slits using machine learning and particle swarm optimization","authors":"Huan-Yi Ren , Si-Liang Sun , Dong Liu , Muhammad Bilal Riaz , Y.S. Hamed , Afraz Hussain Majeed","doi":"10.1016/j.csite.2026.107848","DOIUrl":"10.1016/j.csite.2026.107848","url":null,"abstract":"<div><div>Taylor-Couette (T-C) flow commonly occurs in the annular gaps of rotating machinery, and improving its heat transfer performance is essential for effective thermal management. However, existing empirical correlations often have limitations in both efficiency and accuracy. To address this, this study integrates machine learning with optimization algorithms to refine T-C flow configurations that incorporate elliptical slits, aiming to develop a more efficient and precise optimization approach. Four machine learning methods are compared against a predictive correlation to assess their prediction accuracy for T-C flow. The particle swarm optimization (PSO) algorithm is subsequently applied to determine the optimal slit parameters. The results indicate that the Genetic Algorithm-Back Propagation Neural Network (GA-BPNN) model is the most suitable model, showing the highest agreement between predicted and simulated values. By incorporating the PSO algorithm, the optimal slit width of 11.33 mm, slit depth of 12.48 mm, and slit number of 12 are obtained. The predicted results agree well with experimental data, exhibiting a relative error of only 2.99%. Compared to the rectangular slit model, the optimized elliptical slit enhances the Nusselt number by 17%. The methodology and findings presented in this study provide a methodological and technical reference for optimizing and enhancing T<strong>-</strong>C flow systems.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"80 ","pages":"Article 107848"},"PeriodicalIF":6.4,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146777426","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

A hydro-thermal coupling model for artificial ground freezing considering dynamic phase-change and seepage effects: A case study of the freeze-sealing pipe-roof method 考虑动态相变和渗流效应的人工地面冻结水热耦合模型——以冻结封顶管道法为例

IF 6.4 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2026-04-01 Epub Date: 2026-02-18 DOI: 10.1016/j.csite.2026.107838

C.X. Lu , S.B. Xue , H. Li , S.J. Deng

{"title":"A hydro-thermal coupling model for artificial ground freezing considering dynamic phase-change and seepage effects: A case study of the freeze-sealing pipe-roof method","authors":"C.X. Lu , S.B. Xue , H. Li , S.J. Deng","doi":"10.1016/j.csite.2026.107838","DOIUrl":"10.1016/j.csite.2026.107838","url":null,"abstract":"<div><div>During the freezing period in the artificial ground freezing (AGF) method under seepage conditions, frozen curtain development confronts the coupling effect of phase change and seepage pathways. Traditional models often treat the phase change as static phenomena and set the permeability as a constant value. To capture the dynamic evolution of phase change and their impact on permeability, a temperature-dependent smooth step function is introduced as the phase change function, dynamically linked to water saturation. In this study, a 2D double-pipe model is established to validate the accuracy of the model. Considering phase change, the frozen curtain alters the seepage pathways, preventing forming excessively large and impractical freezing curtain. The results demonstrated that the phase change process under this model can be explicitly embedded within the hydro-thermal coupling framework, dynamically altering permeability and seepage pathways. Subsequently, a case study on Freeze-Sealing Pipe-Roof (FSPR) method was conducted using COMSOL Multiphysics. It was found that seepage induces asymmetric frozen curtain thickness at both upstream and downstream, the thickness of the upstream frozen curtain is generally less than that downstream, with the difference becoming more pronounced as seepage velocity increases. At seepage velocities of 0.2, 0.4 and 0.8 m/d, the required freezing time for the frozen curtain thickness achieving 1.5 m are 45 days, 53 days and 80 days respectively. The critical seepage velocity threshold for achieving 1.5 m within 60 days is 0.7 m/d. These findings highlight the necessity of considering coupled phase-change and seepage effects in simulations to ensure safety.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"80 ","pages":"Article 107838"},"PeriodicalIF":6.4,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146778095","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

Enhancing thermal storage in a single-tank molten salt system using fins 利用翅片增强单罐熔盐系统的蓄热性能

IF 6.4 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2026-04-01 Epub Date: 2026-02-24 DOI: 10.1016/j.csite.2026.107858

Yuan Wang , Guangjie Gong , Yanmei Zhang , Weijie Zhao , Jianing Xue , Ranyue Yang , Chengbin Zhang , Zilong Deng

{"title":"Enhancing thermal storage in a single-tank molten salt system using fins","authors":"Yuan Wang , Guangjie Gong , Yanmei Zhang , Weijie Zhao , Jianing Xue , Ranyue Yang , Chengbin Zhang , Zilong Deng","doi":"10.1016/j.csite.2026.107858","DOIUrl":"10.1016/j.csite.2026.107858","url":null,"abstract":"<div><div>Thermal stratification and localized overheating limit the charging rate and capacity of single-tank molten salt thermal storage systems driven by single source heaters. To address these challenges, this study is the first to systematically optimize annular fin geometry for single source molten salt heaters under natural convection, aiming to elucidate the coupling mechanism of fin geometry on natural convection heat transfer. A transient three-dimensional computational fluid dynamics (CFD) model based on the fundamental conservation laws was developed and experimentally validated to simulate the single-phase transient heating process. In this work, the effects of fin radial width and fin number on natural convection intensity, plume evolution, and temperature uniformity are investigated. The simulation results reveal that the annular fins effectively disrupt the thermal boundary layer and suppress the rapid ascent of thermal plumes, thereby intensifying fluid mixing at the tank bottom. Parametric analysis demonstrates that, in terms of extending thermal storage duration, increasing the fin number is more effective than increasing the fin radial width. Specifically, the optimal fin configuration (h<sub>ring</sub> = 0.055m, N<sub>ring</sub> = 9) extended the thermal storage duration by 54.52% compared to the single source heating system, effectively mitigating localized overheating and achieving a significantly more uniform temperature distribution.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"80 ","pages":"Article 107858"},"PeriodicalIF":6.4,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147278942","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