Applied Thermal Engineering最新文献

{"title":"Effect of temperature on composite fouling deposition characteristics of silica particle and calcium carbonate: A molecular dynamics study","authors":"Jingtao Wang,&nbsp;Mingyuan Yang,&nbsp;Yuting Jia,&nbsp;Jialing Yang,&nbsp;Hongliang Chang","doi":"10.1016/j.applthermaleng.2025.126286","DOIUrl":"10.1016/j.applthermaleng.2025.126286","url":null,"abstract":"<div><div>In heat exchangers, silica (SiO₂) and calcium carbonate (CaCO₃) often coexist to form composite fouling, and temperature is a key factor that changes dynamically. To investigate the influence of temperature on SiO₂ particle and CaCO₃ composite fouling, this paper employs two composite fouling models of SiO₂ particle and CaCO₃. Molecular dynamics (MD) simulation methods are used to study the deposition characteristics of composite fouling under different system temperatures and wall temperatures, as well as the influencing laws on the formation of composite fouling. The results showed that, compared with the 323 K system, the thermal motion of atoms in the 363 K system is more intense, and the kinetic energy of ions in the system increases, which accelerates the deposition of composite fouling and shortens the deposition time by 50 %. Meanwhile, the number density of Ca²⁺ ions near the wall increases, and the peak number density of water molecules decreases, leading to a reduction in the compactness of water molecules at the wall. This results in a denser formation of composite fouling clusters on the wall. Compared with a wall temperature difference of 20 K, when the wall temperature difference is higher (100 K), the temperature near the wall is higher, and the diffusion coefficient of ions is larger at the same moment. The peak number density of water molecules on the high-temperature wall is lower, allowing the particle and ions to more easily overcome the barrier posed by the water molecules on the Cu surface, resulting in faster deposition on the high-temperature surface. The deposition time is reduced by a maximum of 55.6 %, while the number of ions adsorbed on the high − temperature wall increases by a maximum of 9 %. The research results help to reveal the influence laws of system temperature and wall temperature differences on composite fouling. It provides important theoretical support for the design or maintenance strategies of heat exchangers and the design of scale inhibitors.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"270 ","pages":"Article 126286"},"PeriodicalIF":6.1,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143686163","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 heat transfer characteristics of CaCO3 pellets during the thermochemical energy storage process in a packed-bed reactor: A dual-scale (2D + 1D) transient numerical study","authors":"Huajing Zhang,&nbsp;Chao Xu,&nbsp;Bowen Xu,&nbsp;Zhirong Liao","doi":"10.1016/j.applthermaleng.2025.126272","DOIUrl":"10.1016/j.applthermaleng.2025.126272","url":null,"abstract":"<div><div>Compared with powdery CaCO₃ materials, milli-sized CaCO₃ pellets offer remarkable advantages in large-scale thermochemical energy storage (TCES) applications. However, there is a lack of a dual-scale packed-bed reactor model that couples the pellet scale and the reactor scale for CaCO₃ pellets TCES. Based on model validation by comparing it with existing experimental data, this study develops a dual-scale packed-bed reactor model for the CaCO₃ pellets TCES reaction. Firstly, the impact of pellet structural parameters and operating conditions on the heat transfer behavior of reaction pellets is evaluated. Then, a sensitivity multivariate analysis reveals the interplay between these key design parameters. The results show that the heating temperature is the most critical factor affecting the TCES performance of CaCO₃ pellets. When the heating temperature is raised from 1073 K to 1223 K, the overall conversion of pellets increases from 39.15% to 85.50% after 12 h. The size of the pellets significantly affects the heat transfer between the heating fluid and the pellets, as well as within the pellets. As the pellet radius increases from 0.25 mm to 5 mm, the maximum radial average temperature difference between the pellets and the heating fluid (HTF) increases from about 0.23 K to 19.03 K. Increasing the porosity of the pellets and accelerating the inlet velocity of the HTF both enhance the surface heat transfer between the HTF and the pellets. These results contribute to predicting the conversion behavior and the coupled multi-physics transport processes of CaCO₃ pellets in packed-bed reactors.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"271 ","pages":"Article 126272"},"PeriodicalIF":6.1,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143715603","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":"Numerical analysis and correlation comparison of void fraction in refrigerant two-phase flow in horizontal tubes","authors":"Chenxu Liu ,&nbsp;Fang Wang ,&nbsp;Yuping Gao ,&nbsp;Yongyu Zheng ,&nbsp;Rixin Li","doi":"10.1016/j.applthermaleng.2025.126276","DOIUrl":"10.1016/j.applthermaleng.2025.126276","url":null,"abstract":"<div><div>This study explores the void fraction in R290 refrigerant two-phase flow within small-diameter horizontal tubes through numerical simulations and correlation comparisons. Although there has been extensive research on traditional refrigerants, there is a lack of data and predictive correlations for R290, a promising low-global-warming-potential alternative. By employing the Euler model combined with the Realizable k-epsilon turbulence model, this research examines the void fraction behavior under various conditions, including vapor quality, mass flux, tube diameter, and saturation temperature. The study identifies distinct flow patterns and their impact on void fraction, providing new insights into the two-phase flow dynamics of R290. A key contribution is the evaluation of 35 void fraction correlations, with the El Hajal et al. correlation providing the best predictive accuracy for R290, achieving a Mean Relative Deviation of 1.11% and a Mean Absolute Deviation of 2.37%. This study provides numerical simulation results and a suitable correlation for R290 void fraction prediction, offering a reference for the transition to sustainable refrigerants.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"270 ","pages":"Article 126276"},"PeriodicalIF":6.1,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143686164","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":"Highly efficient adsorption cooling system employing aluminium based adsorbents and water pair","authors":"Benjamin H.W. Teo ,&nbsp;Mai Sheng Ng","doi":"10.1016/j.applthermaleng.2025.126198","DOIUrl":"10.1016/j.applthermaleng.2025.126198","url":null,"abstract":"<div><div>This article presents the thermodynamic framework of adsorption cooling system employing various aluminium based (Al) adsorbents – water system. Scanning electron microscopy (SEM) and N₂ adsorption analysis were performed to study the surface characteristics of the Al adsorbents. The thermal stability of the Al adsorbents was characterised through thermogravimetric analyser (TGA). The water uptakes of the adsorbents were measured under static and dynamic conditions by a temperature-dependent humidity gravimetric analyser. The adsorption kinetics of Al adsorbents – water was presented under the operating conditions of adsorption chiller. A simulation study of an adsorption cooling system is conducted using experimental isotherms and kinetics data. The estimated parameters are used in the Thermodynamic Framework of a working adsorption chiller simulation to understand the performance of adopting Al adsorbents + water systems. CAU-10 has the most potential as the next adsorbent for adsorption cooling application as it has higher SCP and COP when operates at shorter cycle time and lower hot water inlet temperature.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"271 ","pages":"Article 126198"},"PeriodicalIF":6.1,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143704953","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":"High accuracy transient thermal modeling for high-burst motor thermal management system based on phase change materials","authors":"Haotian Zhang ,&nbsp;Shuheng Qiu ,&nbsp;Jinhua Chen ,&nbsp;Jixiang Wang ,&nbsp;Bin Xiong ,&nbsp;Xianbei Sun ,&nbsp;Silu Chen ,&nbsp;Chi Zhang","doi":"10.1016/j.applthermaleng.2025.126110","DOIUrl":"10.1016/j.applthermaleng.2025.126110","url":null,"abstract":"<div><div>The motor thermal management system based on solid–liquid phase change materials (SL-PCMs) effectively suppresses transient temperature rises in motors under high-explosion operating conditions. However, the transient thermal behavior of SL-PCMs exhibits significant nonlinearity, which causes difficulties for existing models in terms of convergence or results in reduced accuracy, thus hindering the iterative speed of thermal design in such systems. This study presents two innovations: First, a lumped-parameter thermal network model focusing on the transient melting process of SL-PCM is proposed, which can more efficiently and accurately predict the liquid phase fraction and node temperatures. Second, to address the challenges of traditional solid–liquid interface identification — such as complexity and discreteness — a wavelet transform-based image processing algorithm is introduced. This method not only improves recognition efficiency but also eliminates the uncertainty of traditional edge detection operators in handling ambiguous boundary problems. Experimental results demonstrate the successful continuous identification of the phase interface, with the average error of the proposed model’s predictions improved from 12.1% in existing models to 1.7%. Furthermore, the proposed model is used to evaluate the temperature rise suppression effect of PCM under different heating powers, with results showing that the model offers high predictive accuracy for the system’s thermal limits. The model proposed in this paper holds promising application potential for SL-PCM thermal analysis and design in high-explosion motor thermal management systems.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"271 ","pages":"Article 126110"},"PeriodicalIF":6.1,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143696770","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":"Influence of the deflector surface configuration on thermal environment during rocket launching","authors":"Zhitan Zhou,&nbsp;Yueheng Mi","doi":"10.1016/j.applthermaleng.2025.126277","DOIUrl":"10.1016/j.applthermaleng.2025.126277","url":null,"abstract":"<div><div>During rocket launches, high-temperature and high-pressure exhaust gases from rocket engines impose substantial thermal and mechanical loads on launch platforms. To address this, deflector systems are implemented to effectively guide the exhaust gas deflection and discharge. Numerical simulations of turbulent combustion were conducted based on the hybrid RANS/LES turbulence model combined with finite-rate chemical kinetics, while experimental data validation was conducted to verify the model’s accuracy. Furthermore, a comparative analysis was carried out to investigate the effects of concave, normal, and convex impingement surfaces on the gas jet flow field characteristics. The findings reveal that the concave impingement surface demonstrated the most pronounced effectiveness in reducing thermal loads on the deflector surface. Specifically, compared with the convex configuration, the concave surface exhibited a 7.9% reduction in peak temperature and a 24.3% improvement in flow guidance efficiency. This enhancement is attributed to the concave surface’s expanded reflection area, which effectively suppresses exhaust gas recirculation within the deflector zone, thereby reducing thermal loads on both the export surface and trench zone. However, it should be noted that the concave configuration may induce multiple gas jet interactions near the impingement region, leading to localized concentration of both mechanical stresses and thermal fluxes, which could potentially compromise the deflector system’s longevity and operational reliability. These insights offer critical theoretical foundations for deflector system optimization.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"270 ","pages":"Article 126277"},"PeriodicalIF":6.1,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143686167","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":"Analysis of heat transfer performance and energy efficiency of the microchannel combined with ultrasound waves and nanofluid","authors":"Erhui Jiang ,&nbsp;Cheng’ao Duan ,&nbsp;Dongwei Zhang ,&nbsp;Luotong Fu ,&nbsp;Songzhen Tang ,&nbsp;Lin Wang ,&nbsp;Yonggang Lei ,&nbsp;Yan Peng ,&nbsp;Huailiang Liu ,&nbsp;Xuehong Wu","doi":"10.1016/j.applthermaleng.2025.126268","DOIUrl":"10.1016/j.applthermaleng.2025.126268","url":null,"abstract":"<div><div>The ultrasonic and nanofluid are widely adopted to enhance the heat transfer performance of the microchannel heat sink. However, the incorporation of a high mass fraction of nanofluid would worsen the flow resistance and heat transfer characteristics due to the phenomenon of agglomeration and sedimentation of nanoparticles. To address this issue, the ultrasound waves are used in the liquid cooling loop with the nanofluid serving as the working medium. Furthermore, the combined effect of the ultrasonic and nanofluid on the enhanced mechanism is experimentally investigated. The results indicate that the ultrasonic waves would trigger the ultrasonic cavitation and acoustic streaming effects within the nanofluid, which consequently disturbs the thermal boundary layer and achieves a maximum 19.9 % enhancement of heat transfer efficiency in the microchannel heat sink. In addition, the motion of the nanoparticles is enhanced by ultrasonic waves, which facilitates a reduction of 5.6% and 10% in the friction coefficient and pressure drop, respectively. Moreover, with the mass fraction of 0.08 wt% nanofluid, the microchannel heat sink could reach the optimized enhancement effect in heat transfer performance assisted with the ultrasonic, resulting in a 40.4% increase in heat transfer coefficient. This work also analyzes the energy efficiency of the combined nanofluid and ultrasonic. It can be found that ultrasonic waves could expand the application concentration range for nanofluid in microchannel heat exchangers.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"271 ","pages":"Article 126268"},"PeriodicalIF":6.1,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143696767","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":"Modeling and performance analysis of solar energy and biogas complementary heating system in rural areas","authors":"Yusheng Cao ,&nbsp;Yaowen Chen ,&nbsp;Pengqiao Ren ,&nbsp;Dengjia Wang ,&nbsp;Zhaoben Zhuang ,&nbsp;Wenhao Zhou","doi":"10.1016/j.applthermaleng.2025.126283","DOIUrl":"10.1016/j.applthermaleng.2025.126283","url":null,"abstract":"<div><div>The current solar heating systems encounter significant losses of excess heat during peak daytime hours, while biogas heating systems suffer from a substantial reduction in biogas production under low-temperature conditions. To address the issue of limitations in the practical application of these two energy sources for heating, in this study, a novel solar and biogas complementary heating system is proposed. Through theoretical analysis, the energy and mass coupling balance equation of the system is established, and the mathematical models for key equipment are developed. Then, a flexible feeding anaerobic digestion experiment is conducted, and the existing biogas production kinetics model is updated. The thermal performance of the heating system is analyzed in the case area. Finally, a comparison is made between the complementary heating system and a traditional solar energy and biogas combined heating system in terms of thermal performance. The results indicate that intermittent flexible feeding has a negative impact on biogas generation, and the shorter the feeding time, the higher the biogas production attenuation rate, with a maximum attenuation rate of 6.3 %. With the scale of the solar collector area increasing from 5,000 m² to 10,000 m² while maintaining the biogas subsystem size constant, the solar contribution rate rises from 42 % to 50 %. Similarly, when the daily feeding rate input increases from 40 t/d to 80 t/d with the solar system size held constant, the biogas contribution rate increases from 25 % to 46 %. Under the same operating conditions, the renewable energy contribution rate of the complementary heating system is 4.44 % higher than that of the combined heating system.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"271 ","pages":"Article 126283"},"PeriodicalIF":6.1,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143681037","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":"Internally stowed, radially deployed radiator panels for passive CubeSat thermal control","authors":"Josh R. Cannon ,&nbsp;Kyle N. Havey ,&nbsp;Noah S. Housley ,&nbsp;Rydge B. Mulford ,&nbsp;Brian D. Iverson","doi":"10.1016/j.applthermaleng.2025.126281","DOIUrl":"10.1016/j.applthermaleng.2025.126281","url":null,"abstract":"<div><div>CubeSats experience significant thermal loads due to solar irradiation and the dissipation from electrical components. The high heat dissipation per unit volume can lead to mission failure if not properly managed. Deployable radiators that are externally stowed and passively actuated in response to changes in CubeSat temperature have been explored as a viable solution. This work describes a radially deployed fin array that is stowed within the CubeSat body when the required heat dissipation is low and passively deploys when the required heat dissipation is high. Internal stowage improves thermal transport to the deployable fins and minimizes heat loss when thermal inputs are small. A test article was manufactured and tested in a cryogenically cooled vacuum chamber environment. Thermal simulation of the radiator system was developed using Thermal Desktop and calibrated using test data. A primary goal of this work was to determine the turndown ratio (largest cooling power / smallest cooling power) of the system which specifies the range of dynamic thermal control. For the experimental test conditions, a turndown ratio of 1.98 was achieved when considering heat loss from the entire CubeSat test article when the CubeSat body temperature is 325 K. However, the turndown ratio is much larger when considering only heat loss from the radiator panel thermal control system (8.35), as the heat loss from the panels is minimal when stowed. Results demonstrate the efficiency of a passive thermal control design in regulating CubeSat temperatures and the benefits of an internal stow design. This approach is shown to achieve a reduction in CubeSat body temperature of 60 °C with a phase lag of 10 min.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"270 ","pages":"Article 126281"},"PeriodicalIF":6.1,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143686104","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":"Microscopic flow simulation of acid rock chemical reactions in multi-scale and multi-mineral porous media","authors":"Liang Zhou ,&nbsp;Hai Sun ,&nbsp;Cunqi Jia ,&nbsp;Gloire Imani ,&nbsp;Jun Yao","doi":"10.1016/j.applthermaleng.2025.126244","DOIUrl":"10.1016/j.applthermaleng.2025.126244","url":null,"abstract":"<div><div>The process of mineral dissolution in acid-rock reactions is of research significance for various fields such as oil and gas development and carbon dioxide storage. Natural rocks often contain different types of mineral components, and sub-resolution nanoscale pores can affect flow, mass transfer, and reactions. This study aims to further investigate the effects of mineral component distribution and sub-resolution pores on dissolution under different acid injection conditions. By utilizing the Darcy-Brinkman-Stokes equations to couple multi-scale flow, we establish fluid mass conservation equations that consider the mass exchange between acid solutions and mineral components, as well as mass conservation equations for the mineral components. The results indicate that the presence of horizontally layered dolomite can lead to localized uniform dissolution under conditions of strong convective ability. Under high diffusion coefficients, the combination of dolomite with insoluble minerals is beneficial for breaking the stable dissolution front, and oscillations in curvature can enhance the breakthrough capacity of the acid. In the wormhole model, larger nanoscale pore sizes facilitate the breakthrough of the acid solution. However, under high diffusion coefficients, the differences in permeability growth and breakthrough capacity of the acid solution among different cores are significantly reduced. Quantitative comparisons further demonstrate that the distribution of minerals and pore sizes has a non-negligible impact on dissolution, with the differences in pore permeability growth for different mineral components and nanoscale pore distributions reaching up to 5.02 times and 10.2 times, respectively.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"271 ","pages":"Article 126244"},"PeriodicalIF":6.1,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143681050","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}