Applied Thermal Engineering最新文献

{"title":"Performance optimization of a transcritical-subcritical parallel organic Rankine cycle for diesel engine waste heat recovery: Thermodynamic, economic, and environmental perspectives","authors":"Mahyar Avazpour ,&nbsp;Rahim Khoshbakhti Saray ,&nbsp;Samira Marami Milani","doi":"10.1016/j.applthermaleng.2025.126512","DOIUrl":"10.1016/j.applthermaleng.2025.126512","url":null,"abstract":"<div><div>This research presents a comprehensive investigation of a parallel organic Rankine cycle configuration that combines transcritical and subcritical operations, aimed at recovering waste heat from off-road diesel engines. The study evaluates how different design parameters affect the cycle’s overall performance. The cycle’s efficiency is systematically examined by employing thermodynamic and economic models using R600 as the working medium. The results show that, under defined operating conditions, the cycle delivers a net power output of 11.99 kW, a thermal efficiency of 12.27 %, and an exergy efficiency of 34.72 %. Exergy-based evaluation highlights components such as valves, expanders, and the mixer are more effective in conserving exergy, whereas the condenser performs with comparatively lower efficiency. The high-pressure (HP) evaporator contributes the most to irreversibility, followed by the condenser and low-pressure (LP) evaporator. In terms of exergy destruction contribution, the HP evaporator holds the largest portion (42.6 %), followed by the condenser (21.8 %), LP evaporator (10.2 %), and turbine 2 (6.8 %). The optimization process incorporates a multi-objective strategy using a genetic algorithm, considering exergy efficiency and specific investment cost (SIC) as performance objectives. Based on the bi-objective optimization framework, the maximum exergy efficiency achieved is 45.92 %, with a corresponding SIC of 3350 $/kW.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"273 ","pages":"Article 126512"},"PeriodicalIF":6.1,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143850082","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}

{"title":"Enhanced heat transfer in finned designs for biomedical materials in a pneumatic extruder","authors":"Chuan-Chieh Liao ,&nbsp;Wen-Ken Li","doi":"10.1016/j.applthermaleng.2025.126513","DOIUrl":"10.1016/j.applthermaleng.2025.126513","url":null,"abstract":"<div><div>This study presents an integrated experimental and numerical investigation of heat transfer and melting efficiency in a pneumatic-based extruder for synthetic biomedical materials (SBMs). The research focuses on understanding phase transition dynamics and optimizing fin configurations to enhance thermal performance. A computational model was developed and validated against experimental data, demonstrating strong agreement in melting fraction evolution, phase transition characteristics, and temperature distribution. Velocity field analysis confirmed that thermal conduction played a dominant role throughout the melting process, as the high material viscosity restricted buoyancy-driven flow. The results reveal that the melting process is predominantly governed by conduction due to the high viscosity of polyethylene glycol-polycaprolactone (PEG-PCL), which suppresses natural convection. Comparative analysis of various fin inclinations highlights that a 40° fin configuration provides the most significant enhancement, reducing melting time by 21% compared to the no-fin case. Enhancement ratio analysis further confirms that proper fin inclination improves heat penetration and overall melting efficiency. Additionally, temperature distribution and melt fraction evolution showed that heat penetration was initially concentrated near the heated surface before diffusing inward. These findings provide valuable insights into optimizing thermal management strategies in pneumatic extrusion systems for biomedical applications.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"273 ","pages":"Article 126513"},"PeriodicalIF":6.1,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143844570","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}

{"title":"Optimizing of coupled phase change materials and liquid cooling thermal management for Li-ion battery pack","authors":"Zhuang Kang ,&nbsp;Xiaoyuan Wang ,&nbsp;Ruixue Yin ,&nbsp;Li Xu ,&nbsp;Jinxing Wu ,&nbsp;Sen Wang ,&nbsp;Qingguo Peng","doi":"10.1016/j.applthermaleng.2025.126508","DOIUrl":"10.1016/j.applthermaleng.2025.126508","url":null,"abstract":"<div><div>The rapid augment of electric vehicles (EVs) intensifies the requirements for advanced battery performance in terms of high discharge rates, long cycle life, and high energy density. To ensure the safe operation of high-rate discharge batteries, a hybrid battery thermal management system (BTMS) integrating phase-change material (PCM) and liquid cooling is proposed, which adopts multi-fin channel wrapped cells and multi-layer PCM mixing to achieve better thermal performance of the battery pack at a high discharge rate. The thermal performance of packs with air-cooled, liquid-cooled, PCM-cooled, and coupled BTMSs are evaluated and compared, and effects of liquid-cooling configurations, PCM layer thickness, coolant flow rate, and ambient temperature on thermal regulation are tested. The results demonstrate the coupled BTMS's potential to improve battery safety and performance, providing a viable solution for thermal management in EV batteries operating under high discharge rates. Furthermore, a thermal management approach with good working performance and high efficiency is identified. The coupled BTMS battery pack exhibits better performance and temperature uniformity, i.e., <em>T</em>_max = 36.13 °C and Δ<em>T</em> = 4.04 °C, at discharge rate 5C. It provides a feasible solution for the safe operation of power battery at a high discharge rate.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"273 ","pages":"Article 126508"},"PeriodicalIF":6.1,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143838290","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}

{"title":"Equivalent boundary model for turbine film cooling prediction","authors":"Wenjun Guo ,&nbsp;Zhouteng Ye ,&nbsp;Yang Liu ,&nbsp;Jue Fu ,&nbsp;Yan Yan ,&nbsp;Wei Sun ,&nbsp;Jiahuan Cui","doi":"10.1016/j.applthermaleng.2025.126381","DOIUrl":"10.1016/j.applthermaleng.2025.126381","url":null,"abstract":"<div><div>Film cooling is a crucial technology for the thermal protection of gas turbines. The simulation of film cooling with mesh-resolved structures remains a time-intensive process, posing significant challenges for turbine optimization. To reduce the computational cost, this paper introduces an innovative equivalent boundary model (EBM) for predicting turbine film cooling. The proposed approach numerically characterizes the coolant jet process by modeling jet injection through the flow function and correcting jet mixing interactions using heat enthalpy balance principles. Validation was performed on a flat plate, the experimental results and the mesh-resolved simulations were used as a comparison. Different indicators of film cooling including mesh sensitivity, cooling efficiency, and flow distribution are examined. Notably, a comprehensive implementation framework for turbine prediction is proposed for the first time, with further applications extending to a turbine vane cascade and a turbine stage. The results show that the cooling effectiveness and aerodynamic performance predicted by EBM closely align with the mesh-resolved simulations and experimental results. Furthermore, for several test cases, the required computational grid was reduced by 20%, 23%, and 38%, respectively, leading to an average simulation time savings of approximately 30%. Providing an effective and efficient tool for predicting and optimizing air-cooled turbines.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"273 ","pages":"Article 126381"},"PeriodicalIF":6.1,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143851649","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}

{"title":"Latest progress on the thermal-hydraulics research in lead-cooled fast reactors: A review","authors":"Kejian Dong ,&nbsp;Sina Li ,&nbsp;Sihong He ,&nbsp;Wei Deng ,&nbsp;Jingtan Chen ,&nbsp;Shahid Ali Khan ,&nbsp;Peng Ding ,&nbsp;Wenhuai Li ,&nbsp;Xiaoming Lan ,&nbsp;Haidong Liu ,&nbsp;Deqi Chen ,&nbsp;Jiyun Zhao","doi":"10.1016/j.applthermaleng.2025.126479","DOIUrl":"10.1016/j.applthermaleng.2025.126479","url":null,"abstract":"<div><div>Lead-cooled fast reactors (LFR) stand out as a promising frontier in advanced nuclear reactor technology, boasting inherent safety features and efficient heat transfer. A comprehensive understanding of thermal-hydraulics is vital for reactor design and safety. This paper reviews thermal-hydraulics research in LFR, categorized into operation and accident conditions, presenting current research status, gaps, and future directions. During routine reactor operation within designed safety limits, the research emphasizes steady-state flow and heat transfer in the fuel bundle, flow-induced vibration, and natural circulation performance. In contrast, in accidents that potentially surpass safety limits and result in radiation release, the research delves into severe scenarios such as flow blockage, steam generator tube rupture, and thermal stratification during scram. Despite significant progress, key challenges remain. Main research gaps include integrating multi-physical and multi-scale research for full-scale reactor applications, unifying accident severity assessment, and developing advanced sensors in harsh lead/LBE environments. Interdisciplinary collaboration, advanced modeling, experimental validation, and sensor development are essential to address these gaps effectively. Overall, this review provides a foundation for researchers and engineers to address critical challenges, supporting the development of LFR.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"273 ","pages":"Article 126479"},"PeriodicalIF":6.1,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143851654","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}

{"title":"Heat transfer characteristics of Taylor flow in a bottom-heated square microchannel: A 3D conjugate heat transfer numerical study","authors":"Changliang Wang,&nbsp;Yingtao Zhang,&nbsp;Zunlong Jin,&nbsp;Dingbiao Wang,&nbsp;Haobo Shen,&nbsp;Zhenghao Liu","doi":"10.1016/j.applthermaleng.2025.126509","DOIUrl":"10.1016/j.applthermaleng.2025.126509","url":null,"abstract":"<div><div>The heat transfer mechanisms of Taylor flow in rectangular microchannels under asymmetric heating conditions remain incompletely understood. In this work, a three-dimensional conjugate heat transfer numerical simulation method is developed, which can achieve different Taylor flow distribution characteristics by modulating the second-phase volume fraction at the inlet boundary. Using this method, the heat transfer characteristics of gas–liquid Taylor flow in a rectangular channel under asymmetric bottom heating conditions were systematically studied for the first time. The simulation results show good agreement with our previous experimental results, verifying the reliability of the model. Heat transfer paths within bubbles and liquid slugs under bottom heating conditions were analyzed in detail based on three-dimensional velocity and temperature fields. The local Nusselt number distributions for single-phase flow and Taylor flow at various typical locations within the rectangular microchannel are compared, and it is found that the heat transfer enhancement effect of Taylor flow is evident throughout the entire channel. The heat transfer associated with leakage flow at channel corners has been investigated, revealing that the leakage flow in gas–liquid systems is characterized by low velocity and non-uniform distribution. The formation mechanism of the localized vortex at the tail of the bubble and its impact on heat transfer in the entire liquid film region were analyzed. A comprehensive investigation was conducted on the three-dimensional recirculation flow field distribution characteristics of Taylor flow in rectangular microchannels and the intrinsic mechanisms of heat transfer enhancement by short slugs. It was found that the velocity distribution within the short slug no longer conforms to the classical Poiseuille-flow profiles, and the “stagnant heat zone” in the bubble region disappears. Under the conditions of constant void fraction and mixture velocity, reducing the slug length by 60% decreases the average absolute recirculation time within the slug by approximately 53.2 % and increases the Nusselt number by 34 %.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"273 ","pages":"Article 126509"},"PeriodicalIF":6.1,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143844569","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}

{"title":"Investigation of the impact of the thermodynamic property method on the performance, preliminary component sizing and maximum efficiency configuration of the NET power cycle","authors":"Ivan Velazquez ,&nbsp;Frederiek Demeyer ,&nbsp;Miriam Reyes","doi":"10.1016/j.applthermaleng.2025.126491","DOIUrl":"10.1016/j.applthermaleng.2025.126491","url":null,"abstract":"<div><div>This paper investigates the effect of thermodynamic property methods on the NET Power cycle, which is a novel supercritical CO₂ power cycle based on the oxy-combustion technology. A numerical model of the most advanced configuration of NET Power cycle and air separation unit was developed in Aspen Plus to characterize the thermodynamic performance, key components presizing, and maximum efficiency operating configuration. The Peng-Robinson cubic Equation of State (EoS) has traditionally been adopted as the reference EoS (REF EoS) in previous thermodynamic studies on the NET Power cycle. However, its elevated predictive uncertainty, especially in phase modeling, may have led to inconsistent results. For that reason, and as a novelty, in present work, different EoS such as cubic, viral, SAFT and multiparametric Helmholtz free energy-based methods were considered, to evaluate the effect of the EoS on the cycle components and to optimize the operating conditions of the cycle. REFPROP + LKP was also included as the most reliable method. The results reveal that REFPROP + LKP estimates a fluid density in the liquid-like phase pumping stages 25 % higher than the cubic EoSs at nominal conditions. Thus, the compression work is 11.57 % lower and the net cycle efficiency 1.48 % higher. The higher relative deviations in cycle efficiency were obtained with PC-SAFT and GERG-2008 models. REF EoS estimates a recirculation pump impeller diameter 7.49 % larger than REFPROP + LKP. An oversized pump would operate outside the design point with low efficiency, flow control difficulties, and potential vibration and overpressure issues. For REFPROP + LKP, the heat exchange area required by the recuperator is 6.46 % lower than that estimated by REF EoS. This suggests that the manufacturing costs are significantly lower and transient response faster than expected. The maximum cycle efficiency resulted in 55.94 %, for a combustor outlet temperature of 1103.93 °C, turbine inlet and outlet pressures of 273.99 bar and 44.83 bar, and bypass split fraction of 11.37 %.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"273 ","pages":"Article 126491"},"PeriodicalIF":6.1,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143854875","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}

{"title":"Design and performance optimization of non-imaging concentrating photovoltaic thermal systems using grey relational analysis and response surface methodology","authors":"Abid Ustaoglu ,&nbsp;Bilal Kursuncu ,&nbsp;Volkan Akgül ,&nbsp;Junnosuke Okajima","doi":"10.1016/j.applthermaleng.2025.126482","DOIUrl":"10.1016/j.applthermaleng.2025.126482","url":null,"abstract":"<div><div>Non-imaging concentrators enhance photovoltaic thermal system efficiency by improving solar energy capture. However, selecting the optimal concentrator geometry remains challenging due to efficiency, cost, and acceptance angle constraints. This study optimizes concentrating photovoltaic thermal (CPVT) design using compound parabolic (CPC), V-trough, and compound hyperbolic (CHC) concentrators with varying truncation levels and incidence angles. By integrating Grey Relational Analysis (GRA) and Response Surface Methodology (RSM), forty-eight CPVT configurations were uniquely analyzed to identify the best balance between performance, geometry, and cost. The results indicate that V-trough achieved the highest thermal efficiency (66.2% at 0°) and was particularly effective at small angles. CPC maintained stable efficiency across configurations, with moderate truncation (55%), reducing material costs while preserving performance making it a cost-effective option. CHC exhibited the steepest efficiency decline (64.9% to 30.0%) as the incidence angle increased. Due to lower PV temperatures, electrical efficiency improved with incidence angle and smaller reflectors, peaking at 30° with 0.42 truncation. Truncation effects varied by concentrator type, with CPC being the least sensitive. GRG analysis shows that CHC remains more stable at higher incidence angles. RSM identifies incidence angle as the most influential performance factor, indicating that sun tracking may be necessary at larger angles. These findings provide a structured framework for CPVT system optimization, offering insights into the role of truncation and incidence angles in enhancing efficiency and economic feasibility, supporting large-scale adoption by reducing material costs while maintaining energy output, and making it a sustainable solution for enhanced solar energy utilization.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"273 ","pages":"Article 126482"},"PeriodicalIF":6.1,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143838288","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}

{"title":"All-in-one design and fabrication of vacuum insulation panels for ultra-efficient pipeline thermal management","authors":"Zhou Chen ,&nbsp;Jifan Miao ,&nbsp;Hui Chen ,&nbsp;Hongfeng Li ,&nbsp;Qing Wang ,&nbsp;Haixia Zhang ,&nbsp;Yong Yang","doi":"10.1016/j.applthermaleng.2025.126501","DOIUrl":"10.1016/j.applthermaleng.2025.126501","url":null,"abstract":"<div><div>Effective thermal insulation is vital for minimizing heat loss in high-temperature pipeline systems. Conventional insulation materials, such as glass wool and polyurethane (PU) foam, are limited by high thermal conductivities (0.023–0.04 W/(m·K)) and bulky structures. Here, we introduce an all-in-one design and fabrication approach for special-shaped vacuum insulation panels (VIPs), achieving an ultra-low thermal conductivity of 0.0017 W/(m·K). The developed process enables the production of cylindrical VIPs for pipeline insulation while effectively mitigating thermal bridging effects. A double-layer VIP structure with staggered gaps further enhances insulation performance, significantly reducing heat loss. Infrared imaging confirms superior thermal efficiency, with outer surface temperatures as low as 9.5 °C, compared to 35 °C for traditional glass wool insulation. This scalable approach offers a promising solution for ultra-efficient pipeline thermal management.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"273 ","pages":"Article 126501"},"PeriodicalIF":6.1,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143838283","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}

{"title":"Selection of lubricant oils for high temperature heat pumps: A review and selection methodology guidelines","authors":"M.E.H. Tijani ,&nbsp;Gustavo J. Otero Rodriguez ,&nbsp;Miguel Ramirez ,&nbsp;Jonas Lundsted Poulsen ,&nbsp;Simon Spoelstra","doi":"10.1016/j.applthermaleng.2025.126483","DOIUrl":"10.1016/j.applthermaleng.2025.126483","url":null,"abstract":"<div><div>Lubrication is key to the performance and reliability of high-temperature heat pump systems. The primary function of the oil is to lubricate and protect the compressor. In addition, it also provides cooling of the parts heated by friction, a seal against working medium gas leakage, removes impurities, and reduces the noise produced by the moving parts. To fulfil these tasks the lubricant oil must have the required properties, in particular viscosity, which is temperature and pressure dependent and is impacted by the solubility and miscibility between oil and working medium. There is limited literature dedicated to a concrete selection methodology of appropriate lubricant oils for high temperature heat pumps operating with different working media. The objective of this work is to fill this gap and provide a guiding methodology for the selection of appropriate lubricant oils for these applications. A systematic selection methodology is proposed which involves tribology and chemistry studies, along with wear tests to determine the lubricity properties of oils and their mixtures with working media. In addition, based on an extensive literature review, an overview is given of the most suitable lubricant oils for a given working medium.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"273 ","pages":"Article 126483"},"PeriodicalIF":6.1,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143851652","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}