Applied Thermal Engineering最新文献

{"title":"Potential of scallop bionic damper seal to improve rotor axial force and thermal management in compact turbomachinery unit","authors":"Enbo Zhang,&nbsp;Xu Zhang,&nbsp;Jiaqi Feng,&nbsp;Kunpeng Zhao,&nbsp;Bofeng Bai","doi":"10.1016/j.applthermaleng.2025.127355","DOIUrl":"10.1016/j.applthermaleng.2025.127355","url":null,"abstract":"<div><div>For the radial turbomachinery, the aerodynamic loads acting on the impeller cause axial forces on the rotor system, which may lead to bearings overload failure. To reduce the axial force, a compact design with the compressor and turbine impellers coaxially opposed has been proposed, but the problem of bearing overheating still exists. In this research, a balance piston is designed for a compact Turbine-Compressor (T-C) unit, and the scallop bionic damper seal (SDS) is developed as the piston seal. The high-pressure fluid flows through the clearance between the balance piston and the SDS, creating the differential pressure to balance axial force. The throttled leakage flow facilitates the reduction of downstream bearing temperatures for improved thermal management of the T-C unit. The potential of this novel design to improve the axial force and thermal management of the T-C unit under different operating conditions is experimentally investigated. The results indicate that the balance piston can effectively improve the axial force under the start-up and speed-up, variable and design condition, and off-design condition of the T-C unit. Under inlet pressures of 4–6 MPa, the leakage flow from the SDS facilitates the lower downstream bearing temperatures. The relative cooling capacity is defined to analyze the SDS and balance piston to improve the thermal management of the T-C unit.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"278 ","pages":"Article 127355"},"PeriodicalIF":6.1,"publicationDate":"2025-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144518844","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 study on the evolution of two-phase flow and pressure response of boiling liquid expanding vapor explosion","authors":"Yue Zhang ,&nbsp;Jingchen Feng ,&nbsp;Kuo Wang ,&nbsp;Zerong Guo ,&nbsp;Mingzhi Li ,&nbsp;Wulong Fan ,&nbsp;Xinming Qian","doi":"10.1016/j.applthermaleng.2025.127356","DOIUrl":"10.1016/j.applthermaleng.2025.127356","url":null,"abstract":"<div><div>This paper presents a numerical investigation of evolution of gas-liquid two-phase flow and temperature distribution during the initial stage of the Boiling Liquid Expanding Vapor Explosion (BLEVE). Motivated by the need to prevent catastrophic industrial accidents caused by BLEVE’s rapid pressure transients and thermal shocks, this study focuses on the critical milliseconds after vessel failure through the VOF computational fluid dynamics model. The results indicate that following the vessel failure, the initial temperature distribution demonstrated the characteristic of a lower temperature at the initial two-phase interface. The low-temperature region gradually enlarged as the two-phase flow developed and expanded rapidly. At the same time, a “liquid hammer” effect formed, impacting the top wall of the vessel, which caused a significant pressure rebound. Moreover, this paper studied the effect of the initial pressure, the filling rate and the opening diameter separately on the typical parameters of pressure response, such as the stagnation time, the pressure recovery ratio and so on. The results indicate that the pressure recovery ratio increased with the increasing of initial pressure, and as the filling rate rose, the pressure recovery ratio initially increased, then stabilized, and subsequently increased again. Additionally, the pressure recovery ratio decreased with the increasing opening diameter. This study provides some basic references for accident prevention of BLEVE and industrial safety design.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"278 ","pages":"Article 127356"},"PeriodicalIF":6.1,"publicationDate":"2025-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144523837","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":"Upgrading phosphoric acid fuel cell waste heat through isopropanol-acetone-hydrogen chemical heat pump for storage purposes","authors":"Huizhen Liu ,&nbsp;Xuefeng Wang ,&nbsp;Tao Jiang ,&nbsp;Houcheng Zhang","doi":"10.1016/j.applthermaleng.2025.127353","DOIUrl":"10.1016/j.applthermaleng.2025.127353","url":null,"abstract":"<div><div>The inherent electrochemical reaction mechanism of phosphoric acid fuel cells (PAFCs) results in a substantial portion of hydrogen energy being released as waste heat, which adversely affects energy efficiency, operational stability, and economic viability. In this study, we propose a novel hybrid system that integrates an isopropanol-acetone-hydrogen chemical heat pump to capture and convert this waste heat for storage purposes. A steady-state, system-level model is developed based on electrochemical and thermodynamic principles to predict the system’s performance by quantifying irreversible losses arising from energy transfer and conversion processes. Simulation results indicate that the hybrid system achieves a peak output power density of 5448.07 W m^–2, an energy efficiency of 47.02 %, and an exergy efficiency of 50.03 %, corresponding to improvements of 16.26 %, 10.17 %, and 10.09 %, respectively, compared to a standalone PAFC at 473 K. Exhaustive parametric studies show that increases in operating temperature, charge transfer coefficient, and exchange current density of the fuel cell positively improves overall output performance. Conversely, output performance diminishes as electrolyte thickness or the pre-reaction hydrogen-to-acetone molar ratio increases. Local sensitivity analysis identifies electrolyte thickness as the key parameter influencing hybrid system efficiency, underscoring its critical importance for optimization efforts.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"278 ","pages":"Article 127353"},"PeriodicalIF":6.1,"publicationDate":"2025-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144549240","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 on the thermal behavior and optimization of a phase change cold energy storage device with thermoelectric coolers as a cold source","authors":"Chongbo Sun ,&nbsp;Yanhua Diao ,&nbsp;Dongran Fang ,&nbsp;Yaohua Zhao ,&nbsp;Fulin Yang ,&nbsp;Yuhan Li ,&nbsp;Chunjia Ma ,&nbsp;Wenhang He","doi":"10.1016/j.applthermaleng.2025.127307","DOIUrl":"10.1016/j.applthermaleng.2025.127307","url":null,"abstract":"<div><div>Combining the advantages of phase change cold energy storage devices (PCCESDs) and thermoelectric coolers (TECs) is an effective method to efficiently utilize clean energy and reduce the mismatch between energy supply and demand. However, research on PCCESD using TEC as the cooling source is limited. In this paper, a novel PCCESD based on flat miniature heat pipe arrays utilizing TEC as the cooling source is numerically studied and optimized. The study examines the influence of fin structure and phase change temperature of the phase change materials (PCMs) on the device’s performance. Additionally, an orthogonal experiment method is employed to determine the optimal fin structure. Results show that increasing fin height and thickness, along with reducing fin spacing, significantly improves the cooling performance of the TEC and solidification rate of the PCM. Based on the results of orthogonal experiments, the optimal combination for the device’s fin structure includes a fin thickness of 0.1 mm, a height of 30 mm, and a spacing of 2 mm. Compared with the pre-optimization period, the COP of the TEC and solidification velocity of the PCM increase by 10 % and 1.8 %, respectively, but metal consumption only increases by 4.23 × 10⁻⁴ m³. Nonanoic acid with a phase change temperature of 12 °C is also identified as a suitable choice for the device. Under these conditions, the cooling power and COP of the TEC can further improve to 28.43 W and 0.385, representing increases of 60.9 % and 65.9 %, respectively.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"278 ","pages":"Article 127307"},"PeriodicalIF":6.1,"publicationDate":"2025-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144523839","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":"Study on waste heat recovery from sludge drying exhaust gas: Comparisons between pressurized heat exchange coupled with steam compression (PHESC) system and heat pump coupled with steam compression (HPSC) system","authors":"Ruoting Wang ,&nbsp;Wenyi Deng ,&nbsp;Lihua Wang ,&nbsp;Mingtao Hu ,&nbsp;Guodong Wei ,&nbsp;Bingtao Zhao ,&nbsp;Yaxin Su","doi":"10.1016/j.applthermaleng.2025.127336","DOIUrl":"10.1016/j.applthermaleng.2025.127336","url":null,"abstract":"<div><div>This study investigated efficient waste heat recovery from sludge drying exhaust gas by comparatively analyzing two innovative systems: the pressurized heat exchange with steam compression (PHESC) and the closed-loop water heat pump with steam compression (HPSC). Through theoretical modelling and pilot-scale testing, the systems’ thermal performance, energy efficiency, and economic viability were evaluated. Results demonstrate that HPSC exhibits superior stability and recovery capacity, achieving a waste heat recovery rate of 72.8 % and a recovery power of 679.1 kW at optimal conditions, outperforming PHESC’s maximum recovery rate of 67.8 %. Economically, HPSC generates direct benefits of 49.7–72.6 CNY per ton of wet sludge, markedly higher than PHESC’s range (−7.1 to 69.9 CNY/t). While both systems show higher operational energy consumption than theoretical predictions, HPSC proves more adaptable for large-scale industrial applications due to its robust heat transfer mechanism and economic advantages. This work highlights HPSC’s potential as a novel and sustainable solution for simultaneous energy recovery and operational stability in sludge thermal drying, advancing industrial waste heat recovery strategies for high-pollution exhaust streams.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"278 ","pages":"Article 127336"},"PeriodicalIF":6.1,"publicationDate":"2025-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144549238","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 a hybrid direct/indirect expansion solar-air dual source heat pump system for building application","authors":"Sofiane Benchamma ,&nbsp;Mohammed Missoum ,&nbsp;Nefissa Belkacem","doi":"10.1016/j.applthermaleng.2025.127352","DOIUrl":"10.1016/j.applthermaleng.2025.127352","url":null,"abstract":"<div><div>Investigation of heat pumps performances to meet climatic, economic and sustainable development requirements expands continuously. Heat pumps using solar-air dual heat sources (DSHP) are widely invested in various configurations and components, and they have demonstrated superior performance. Nevertheless, performance improvement efforts were predicated on the system functioning as either direct-expansion or indirect-expansion DSHP system separately. In this work, the performance of a new configuration of a DSHP system operating in three different modes, direct solar mode (DSM), indirect solar mode (ISM) and both direct/indirect solar mode (D/ISM) is investigated. The system includes a photovoltaic thermal collector, two storage tanks and a heat pump with a composite evaporator. The system supplies domestic hot water and space heating for a residential building located in the coldest region of Algeria.</div><div>First, a mathematical model of a direct-expansion single source SAHP was developed. Next, a model of an indirect-expansion DSHP system is created under TRNSYS environment. Subsequently, the two models are integrated to evaluate the performance of the new system.</div><div>Results show that throughout the heating period, the system has reached the best performance when operating in D/ISM. The coefficient of performance, seasonal performance and solar fraction are 2.89, 9.19 and 63%, respectively. The parametric study indicates that the system performance is influenced by PVT and solar collector evaporator areas, but the set-point temperature of tanks has little impact. Economically, the D/ISM has the shortest payback period compared to DSM and ISM.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"278 ","pages":"Article 127352"},"PeriodicalIF":6.1,"publicationDate":"2025-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144523831","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":"Experimental study on heat transfer and thermal storage performance of tunnel GHEs in cold regions","authors":"Lifei Zheng ,&nbsp;Zhiying Zhong ,&nbsp;Zhi Chen ,&nbsp;Sheng Yang ,&nbsp;Xinlong Zhou ,&nbsp;Henglin Xiao","doi":"10.1016/j.applthermaleng.2025.127344","DOIUrl":"10.1016/j.applthermaleng.2025.127344","url":null,"abstract":"<div><div>Frost damage at tunnel entrances in severely cold regions presents a major threat to tunnel safety and operational reliability. To address this challenge, this study investigates the use of tunnel lining ground heat exchangers (GHEs) for active frost prevention. A test platform for ground heat exchangers was established in laboratory, enabling a systematic analysis of GHE heat transfer performance and surrounding rock heat retention under varying operational and environmental conditions, including inlet temperature, flow velocity, pipe arrangement, ambient temperature, and ventilation speed. Results indicate that raising the inlet temperature and flow velocity improves the heat exchange rate, although the improvement effect weakens at higher levels due to nonlinear behavior. A pipeline configuration aligned with the tunnel axis increases the heat exchange rate by about 7.7 %. A 5 °C decrease in ambient temperature results in roughly a 10 % increase in heat loss and a 10 % decline in thermal retention, especially pronounced in the −8 °C to −18 °C range. Ventilation velocity has a pronounced impact; increasing it from 0 m/s to 1 m/s significantly alters both heat loss and thermal retention. The system shows greater sensitivity to ventilation variation under conditions of low inlet temperature and high flow rate. These findings offer guidance for the engineering application and optimization of GHE systems in tunnels situated in cold climates.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"278 ","pages":"Article 127344"},"PeriodicalIF":6.1,"publicationDate":"2025-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144514062","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":"Comparison and analysis of different machine learning models for predicting air-conditioning cooling loads in comprehensive large public buildings across various time scales","authors":"Jingtao Liu ,&nbsp;Yuxiang Zhang ,&nbsp;Zhihong Zhai ,&nbsp;Yixian Wang ,&nbsp;Lifei Ye ,&nbsp;Yunfei Ding","doi":"10.1016/j.applthermaleng.2025.127328","DOIUrl":"10.1016/j.applthermaleng.2025.127328","url":null,"abstract":"<div><div>Large-scale comprehensive public buildings feature complex functionalities and drastic fluctuations in air-conditioning cooling loads, posing significant challenges to accurate prediction. Cooling load forecasting at different temporal scales enables the fulfillment of varied energy-saving control requirements, such as real-time control, optimization of HVAC operational efficiency, and formulation of cold storage/release schedules. However, most existing studies focus on single-function buildings and single-time-scale cooling load forecasting. To explore accurate multi-time-scale cooling load prediction for large-scale comprehensive public buildings, this study employs six defferent neural networks, namely Long Short-Term Memory (LSTM), Gate Recurrent Unit (GRU), Recurrent Neural Network (RNN), Backpropagation algorithm (BP), Temporal Convolutional Network (TCN) and Extended Long Short-Term Memory (XLSTM), to develop and compare 18 machine learning models for daily, hourly, and ten-minute time scales. A comprehensive analysis of model performance is conducted based on prediction accuracy and computational efficiency. The results demonstrate that different models exhibit varying prediction performances across distinct time scales, particularly in terms of prediction accuracy and runtime. Meanwhile, an improved prediction optimization method is proposed, which reduces the Mean Absolute Percentage Error (MAPE) by 36.25 % and increases the coefficient of determination (R²) by 14.62 % compared to non-optimized approaches. Furthermore, the research presented in this paper fills a gap in the field of air-conditioning cooling load prediction for comprehensive large public buildings using various neural networks across different time scales. This is of great significance for real-time control of air-conditioning cooling, efficient utilization and storage of cooling capacity, and the realization of energy-efficient machine rooms.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"278 ","pages":"Article 127328"},"PeriodicalIF":6.1,"publicationDate":"2025-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144523833","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":"CFD and Machine learning-based predictive modeling of natural convection in non-Newtonian nano-encapsulated phase change material within an Enclosure with a corrugated heated cylinder","authors":"Md. Mejbah Ullah Chowdhury ,&nbsp;Jawad Ibn Ahad ,&nbsp;Md. Mamun Molla ,&nbsp;Preetom Nag ,&nbsp;Azad Rahman","doi":"10.1016/j.applthermaleng.2025.127240","DOIUrl":"10.1016/j.applthermaleng.2025.127240","url":null,"abstract":"&lt;div&gt;&lt;div&gt;Enhancing heat transfer and energy storage presents challenges in renewable energy applications. This study examines the thermal efficiency of power-law non-Newtonian nano-encapsulated phase change materials (NEPCM) in a cavity with a corrugated cylinder under natural convection. A non-dimensional framework was developed using the Galerkin finite element method (GFEM), with Polyethylene Glycol (PEG) as the base fluid. Machine learning-based predictive modeling was integrated with computational fluid dynamics (CFD) framework to provide a more reliable approach. The study numerically examined the effect of different non-dimensional parameters, including Rayleigh number &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;mi&gt;a&lt;/mi&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;4&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;6&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, Hartmann number &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;mi&gt;a&lt;/mi&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;90&lt;/mn&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, power-law index &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mi&gt;n&lt;/mi&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;mo&gt;.&lt;/mo&gt;&lt;mn&gt;7&lt;/mn&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mo&gt;.&lt;/mo&gt;&lt;mn&gt;4&lt;/mn&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, Prandtl number &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mi&gt;P&lt;/mi&gt;&lt;mi&gt;r&lt;/mi&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mn&gt;200&lt;/mn&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, Stefan number &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mi&gt;S&lt;/mi&gt;&lt;mi&gt;t&lt;/mi&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;mo&gt;.&lt;/mo&gt;&lt;mn&gt;313&lt;/mn&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, and fusion temperature &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;θ&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;f&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;mo&gt;.&lt;/mo&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;mo&gt;.&lt;/mo&gt;&lt;mn&gt;8&lt;/mn&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;. It examines streamline, isotherm, entropy generation, heat capacity ratio &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mi&gt;C&lt;/mi&gt;&lt;mi&gt;r&lt;/mi&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, Nusselt number &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;mi&gt;u&lt;/mi&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, and Bejan number &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mover&gt;&lt;mrow&gt;&lt;mi&gt;B&lt;/mi&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;/mrow&gt;&lt;mo&gt;¯&lt;/mo&gt;&lt;/mover&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;. Five machine learning models-Decision Tree, Random Forest, KNN, XGBoost, and LightGBM-were used to predict fluid behavior. Results show that increasing &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;mi&gt;a&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; reduces vortices, bringing NEPCM’s heat transient phase closer to the cylinder. Higher &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;θ&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;f&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; shrinks the melting region, and &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;mi&gt;u&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; peaks at &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;mi&gt;a&lt;/mi&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;6&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, decreasing with higher &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;mi&gt;a&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; due to the magnetic field. At &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;mi&gt;a&lt;/mi&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mn&gt;90&lt;/mn&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, &lt;span&gt;&lt;math&gt;&lt;mover&gt;&lt;mrow&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;mi&gt;u&lt;/mi&gt;&lt;/mrow&gt;&lt;mo&gt;¯&lt;/mo&gt;&lt;/mover&gt;&lt;/ma","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"278 ","pages":"Article 127240"},"PeriodicalIF":6.1,"publicationDate":"2025-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144518830","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":"Experimental and numerical study of seawater freezing coupled with ice growth dynamics and heat/mass transfer","authors":"Xingxiang Xie ,&nbsp;Yangui Chen ,&nbsp;Leyang Dai ,&nbsp;Lijie Xu","doi":"10.1016/j.applthermaleng.2025.127329","DOIUrl":"10.1016/j.applthermaleng.2025.127329","url":null,"abstract":"<div><div>Seawater cold thermal energy storage offers high efficiency, environmental benefits, and abundant availability, making it promising for load shifting and energy system optimization. However, current seawater freezing models struggle to accurately capture the multiscale dynamics of ice formation and associated heat and mass transfer, limiting system performance improvement. To address this, a multiscale seawater freezing model is developed by coupling microscopic ice crystal growth mechanisms with macroscopic refrigeration system behavior. The model investigates seawater’s thermophysical transport and freezing kinetics. Ice crystal growth parameters are extracted through microscale simulations, and a kinetic model is constructed using the Arrhenius equation and hybrid particle swarm optimization (HPSO). This kinetic model is integrated into a system-level simulation to predict the freezing process in a cold storage tank under realistic conditions. The model achieves high accuracy, with maximum errors of 0.9 °C for water temperature, 4 mm for ice thickness, 1.5 °C for refrigerant outlet temperature, and 0.02 MPa for outlet pressure. Compared with the traditional enthalpy-porosity model (EPM), the proposed model reduces the water temperature error by 40 % and improves ice thickness accuracy, reducing the maximum error from 15 mm to 4 mm. Furthermore, salinity significantly influences salt rejection, temperature evolution, heat transfer coefficient, cooling capacity, and thermal storage performance. A 3 % salinity seawater achieves the best performance due to a favorable balance between temperature difference and heat transfer efficiency. This study provides theoretical insights and technical support for enhancing seawater freezing models and optimizing system-level cold thermal storage design.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"278 ","pages":"Article 127329"},"PeriodicalIF":6.1,"publicationDate":"2025-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144518845","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}