Applied Thermal Engineering最新文献

{"title":"A comprehensive investigation of phase change energy storage device based on structural design and multi-objective parameter optimization","authors":"Lu Liu ,&nbsp;Hongxin Yu ,&nbsp;Bo Tian ,&nbsp;Ningbo wang ,&nbsp;Cong Gong ,&nbsp;Qiu Tu ,&nbsp;Shuangquan Shao","doi":"10.1016/j.applthermaleng.2025.126374","DOIUrl":"10.1016/j.applthermaleng.2025.126374","url":null,"abstract":"<div><div>Latent heat thermal energy storage technology has emerged as a critical solution for medium to long-term energy storage in renewable energy applications. This study presents a comprehensive optimization for enhancing the structural configuration of a phase change energy storage device (PCESD) through multi-objective optimization. Four essential performance metrics, e.g., average temperature, melting fraction, temperature uniformity, and energy storage efficiency are identified as key performance indicators. A comprehensive numerical simulation is performed to investigate the impact of various macro-encapsulation methods on thermal performance characteristics. Further, the effects of design variables, like inlet flow rate, inlet temperature, the thermal conductivity of phase change material, and latent heat of phase change material on the 4 key performance indicators are quantitatively analyzed through parametric investigation. The multi-objective optimization framework integrates the response surface, NSGA-II, and entropy weight-TOPSIS methods for the PCESD system. The optimal performance of the PCESD system is achieved with exceptional temperature uniformity of 1.14 K and superior energy storage efficiency of 1599.95. The systematic optimization methodology provides a novel perspective for the PCESD design, which is expected to promote the further application of latent heat thermal energy storage technology in renewable energy conservation.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"272 ","pages":"Article 126374"},"PeriodicalIF":6.1,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143776430","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":"Comparative study of operational characteristics for two-phase loop thermosyphons with and without pump assistant: Heat transfer performance and high-speed visualization observation","authors":"Jian Qu,&nbsp;Yun Zhao,&nbsp;Yu Hua,&nbsp;Wenlong Yang,&nbsp;Shan Gao","doi":"10.1016/j.applthermaleng.2025.126382","DOIUrl":"10.1016/j.applthermaleng.2025.126382","url":null,"abstract":"<div><div>The startup and heat transfer characteristics of pump-assisted two-phase loop thermosyphon (PTPLT) was experimentally investigated and compared with a TPLT using R245fa as the working fluid. To understand the coupling relationship between the operational performance and flow behaviors for the PTPLT, high-speed visualization observation was conducted and compared to the pump-free condition. The addition of pump ensured smooth startup and mitigated the temperature overshoot as compared with the TPLP. The local intermittent dry-out at the evaporator region could be suppressed with the increase of pump power, and a flow regime map was developed. The utilization of pump is beneficial to mitigating geyser boiling and transitioning to annular flow earlier at the evaporator region. Compared to the TPLT, the thermal resistance was decreased by 2.9–30.1 % within the power input range of 150–550 W for the PTPLT at the pump power range of 1.6–2.4 W. Additionally, the flow boiling heat transfer coefficient (FBHTC) within the evaporator region increased with the pump power. At the combined condition of 550 W power input and 2.4 W pump power, an FBHTC of 2972.6 W/(m²∙K) was achieved, 12.3 % higher than that of the TPLT. This study sheds light on the mechanism of performance improvement for the PTPLT from the perspective of flow visualization and can serve as a guideline for design and applications.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"271 ","pages":"Article 126382"},"PeriodicalIF":6.1,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143760196","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":"Physical-based surrogate model and its application in 3D-1D fusion optimization of a marine two-stroke engine","authors":"Xiao Han ,&nbsp;Long Liu ,&nbsp;Qian Xia ,&nbsp;Dai Liu ,&nbsp;Jianyi Tian","doi":"10.1016/j.applthermaleng.2025.126387","DOIUrl":"10.1016/j.applthermaleng.2025.126387","url":null,"abstract":"<div><div>Marine two-stroke low-speed engines face challenges of complex experimentation and high computational costs, making 1D-3D integrated simulation optimization using surrogate models combined with optimization algorithms a potential solution. However, existing surrogate models suffer from issues such as high data dependency and low interpretability. To address this, this study develops simplified physical-based surrogate models, including a scavenging multi-stage model, a scavenging swirl model, and a swirl mixing controlled combustion (SMCC) surrogate model, calibrated via genetic algorithm (GA). Validation against experimental data shows errors within 5%. These models are coupled to enable full-cycle performance simulation. Subsequent multi-objective optimization using Non-dominated sorting genetic algorithm II (NSGA-II) reduces maximum pressure (<em>P_max</em>) and maximum pressure rise rate (<em>dP_max</em>) by 3.23% and 2.06%, respectively, while improving Brake Thermal Efficiency (<em>BTE</em>) by 1.1%. The optimized surrogate model maintains consistency with CFD results, with errors within 5%, but requires significantly less computational time than traditional CFD-based optimization. Therefore, physical-based simplified surrogate models integrated with optimization algorithms provide an effective approach for system-level simulation and multi-objective optimization of marine two-stroke low-speed engines.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"271 ","pages":"Article 126387"},"PeriodicalIF":6.1,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143747828","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 of phase change transpiration cooling with varying pore distributions under hot gas flow","authors":"Qingyong Zhu,&nbsp;Hao Ying,&nbsp;Shun Lu","doi":"10.1016/j.applthermaleng.2025.126386","DOIUrl":"10.1016/j.applthermaleng.2025.126386","url":null,"abstract":"<div><div>Phase change transpiration cooling demonstrates significant potential as a promising thermal management strategy for addressing thermal loads on high-temperature components operating under high-enthalpy and prolonged heating conditions. This investigation establishes an experimental platform to evaluate phase change transpiration cooling performance on thermally challenged surfaces subjected to high-speed hot gas flow. Utilizing sintered copper porous media as matrix materials with liquid water and kerosene as coolants, the study systematically investigates the synergistic effects of pore distribution, coolant properties, mass flow rate, and incoming flow temperature on cooling performance. Experimental data reveal that water-cooled matrices exhibit a peak cooling efficiency of 0.91. Comparative analysis indicates kerosene cooling attains a maximum average cooling efficiency of 0.76 accompanied by superior thermal homogeneity across the matrix surface, albeit lower cooling capacity. Three characteristic cooling regimes emerge with increasing coolant flow and mainstream temperature variations have little impact on the transpiration cooling performance when the matrix is fully cooled. Critical findings suggest that porous media with reduced pore dimensions and higher porosity demonstrate enhanced thermal performance through elevated capillary and boiling limits, and superior coking resistance under kerosene cooling. This work provides reliable guidance for further research into the design and optimization of transpiration cooling systems in practical applications under high-enthalpy heating conditions.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"271 ","pages":"Article 126386"},"PeriodicalIF":6.1,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143747083","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":"Performance comparison of different well configurations for medium-deep coaxial closed-loop geothermal systems","authors":"Hongxu Chen ,&nbsp;Yan Shi ,&nbsp;Chengcheng Liu ,&nbsp;Zesheng Zhao ,&nbsp;Yaoshuai Yue ,&nbsp;Mingqi Li","doi":"10.1016/j.applthermaleng.2025.126393","DOIUrl":"10.1016/j.applthermaleng.2025.126393","url":null,"abstract":"<div><div>Coaxial closed-loop geothermal systems are gaining prominence for medium-deep geothermal resource exploitation due to their small land footprint and stable heat extraction capability. Addressing the limitations of existing research, which primarily focuses on vertical systems, overlooks formation heterogeneity, and lacks a systematic comparison of well configurations, this study innovatively develops a two-dimensional transient heat transfer model that considers heterogeneous geological formations. For the first time, a comprehensive comparison of the heat extraction and economic performance of vertical, L-shaped, and multilateral coaxial closed-loop geothermal systems under short-term and long-term operation is conducted using a combination of theoretical analysis and Fluent-based numerical simulation. Results indicate that multilateral wells significantly enhance overall performance by increasing well spacing and reservoir contact area. At a mass flow rate of 3 kg/s, the heat extraction per meter of the multilateral well is 28.56 % and 34.11 % higher than that of the L-shaped and vertical wells, respectively, enhancing the system coefficient of performance (COP) by 1.13 % and 1.79 %, respectively. Furthermore, the profits are approximately 79.28 % and 169.84 % higher. Therefore, multilateral wells offer the greatest long-term benefits, followed by L-shaped wells, and finally vertical wells. This study provides a valuable reference for comprehensive evaluation and optimized design of coaxial closed-loop geothermal systems.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"271 ","pages":"Article 126393"},"PeriodicalIF":6.1,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143760294","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":"Development and experimental investigation of hybrid phase change material thermal energy storage prototype by utilising power-to-heat concept","authors":"Saulius Pakalka ,&nbsp;Jolanta Donėlienė ,&nbsp;Matas Rudzikas ,&nbsp;Kęstutis Valančius ,&nbsp;Giedrė Streckienė","doi":"10.1016/j.applthermaleng.2025.126377","DOIUrl":"10.1016/j.applthermaleng.2025.126377","url":null,"abstract":"<div><div>The paper presents experimental research on the hybrid water and phase change material-based thermal energy storage (PCM HTES) prototype. The prototype is designed to apply the concept of power-to-heat, enhance energy storage density by utilising PCM, and be used to prepare domestic hot water (DHW) within the temperature range of 40–65 °C. This design solution was chosen to implement the external arrangement of PCM in a hybrid system and analyse the influence of such geometry on the thermal performance of PCM HTES. Several parameters have been analysed, including the temperature of the water, PCM, and heat exchanger fins, mass flow rate and quantity of DHW, the power and energy consumption of the electric heating element, and thermal energy absorbed and released. The PCM<!--> <!-->HTES charging experiment is carried out in three charging steps (CS) to compare the thermal performance under different initial conditions. The discharging experiment showed that the prototype could provide 46.0 L of 40 °C mixed water (DHW) for up to 8 min 38 s at a constant mass flow rate of 0.09 kg/s. Overall, experimental results showed the feasibility of the power-to-heat concept in high energy storage density PCM-based TES for DHW systems. However, the results revealed a large inertia and temperature gradient, which led to incomplete melting and solidification of the PCM. The results also indicated important areas for improvement and optimisation of PCM HTES to achieve greater energy efficiency and improved integration with the power-to-heat concept and renewable energy sources.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"271 ","pages":"Article 126377"},"PeriodicalIF":6.1,"publicationDate":"2025-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143747049","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":"Aerodynamic characteristics and ventilation losses of turbine in a compressed air energy storage system","authors":"Zekai Li ,&nbsp;Weilin Shu ,&nbsp;Shifang Wu ,&nbsp;Xiaorui Cai ,&nbsp;Sen Li ,&nbsp;Yingzheng Liu","doi":"10.1016/j.applthermaleng.2025.126376","DOIUrl":"10.1016/j.applthermaleng.2025.126376","url":null,"abstract":"<div><div>Compressed Air Energy Storage (CAES) systems frequently operate turbines under part-load or low-load conditions, resulting in substantial energy losses. This study investigates the evolution of flow fields and loss distributions in air turbines operating across 70 operating conditions, ranging from optimal to low-load regimes, using validated numerical methods. Results reveal a critical transition from turbine to compressor mode when the flow coefficient drops below 0.12, marked by the development of uniform spanwise blockage in stator passages and rotor root separation bubbles that redirect flow toward the tip. Aerodynamic and entropy analyses indicate that rotor-airflow interactions are the primary contributors to losses, accounting for about 90 %–95 % of total entropy production. A one-dimensional ventilation model, developed through the integration of Random Forest regression and dimensional analysis, effectively predicts turbine performance across varying conditions. The model highlights airflow velocity (26.0 % contribution) and density (31.6 %) as key predictors, achieving errors of less than 15.0 % for most operating scenarios. By explicitly incorporating flow coefficient effects, the model surpasses classical prediction approaches, offering valuable insights for optimizing turbine performance in low-load CAES operations.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"271 ","pages":"Article 126376"},"PeriodicalIF":6.1,"publicationDate":"2025-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143747835","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 in salt cavern energy storage coupled with water phase transition: Field experiment and modeling approach","authors":"Youqiang Liao ,&nbsp;Tongtao Wang ,&nbsp;Jiasong Chen ,&nbsp;Dongzhou Xie ,&nbsp;Tao He ,&nbsp;Luokun Xiao","doi":"10.1016/j.applthermaleng.2025.126379","DOIUrl":"10.1016/j.applthermaleng.2025.126379","url":null,"abstract":"<div><div>Salt cavern energy storage is deemed to be a key method to regulate the intermittency and instability of clean energy. Heat transfer in salt caverns is a key factor as it influences the temperature profile, creep rate of salt rock, and storage capacity inversion. However, existing heat transfer models experience challenges as temperature reversal phenomena near the gas-brine interface were frequently observed in field experiments. Herein, a 183-day field monitoring experiment was presented to reveal the heat transfer characteristics during gas injection, extraction, and shut-in periods. Four variation trends of temperature profiles with depth and negative temperature gradient were observed for the first time. Thus, the cavity was divided into four heat transfer regions, and a new heat transfer model coupled with water phase transition was presented. The average errors of wellhead pressure, cavity pressure, and cavity temperature are ∼2.99 %, ∼1.83 %, and 2.09 %, respectively. A comparison of temperature profiles first confirmed the brine temperature remained noticeably lower than the formation temperature due to the water phase transition, resulting in the inversion of the temperature gradient at the cavity bottom. The average estimation error of the temperature profiles is 1.92 %, which is considerably better than that of the traditional model (3.03 %). A further look at the storage capacity assessment shows that the new model has the smallest error (∼3.09 %), followed by using methane substitution (∼3.55 %) and the geothermal gradient-based method (∼4.28 %). This work offers further insights into thermal performance during gas operation and could serve as a powerful tool for the estimation of storage capacity and developing a digital twin system.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"271 ","pages":"Article 126379"},"PeriodicalIF":6.1,"publicationDate":"2025-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143747825","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":"A novel battery thermal management system with air–liquid coupled cooling based on particle swarm optimization","authors":"Feifei Liu,&nbsp;Qilong Yang,&nbsp;Diancheng Zheng,&nbsp;Wu Qin,&nbsp;Xianfu Cheng,&nbsp;Jun Li","doi":"10.1016/j.applthermaleng.2025.126391","DOIUrl":"10.1016/j.applthermaleng.2025.126391","url":null,"abstract":"<div><div>Effective heat dissipation in high-temperature is critical for maintaining the superior performance and power output of lithium-ion batteries (LIBs) for electric vehicles (EVs). Considering the low heat transfer efficiency of air cooling and the high energy loss of liquid cooling, a novel battery thermal management system (BTMS) coupled forced air cooling and liquid cooling was established. The thermal behaviors of absolute air-cooled, absolute liquid-cooled and air–liquid coupled cooled (ALCC) BTMS were compared at 2C discharge rate based on the thermal model verification of LIBs. Additionally, the effects of structure parameters of the ALCC plate on heat dissipation performance and energy loss were investigated using response surface methodology, and the structure was optimized using the particle swarm optimization. The results indicate that ALCC BTMS can achieve almost the same heat dissipation performance with only one-third of the energy loss of absolute liquid-cooled BTMS, and the optimized ALCC plate can reduce the maximum temperature by 1.0 %, the maximum temperature difference by 8.8 %, and the energy loss by 22.0 % at 2C discharge rate. Finally, the optimized ALCC plate is verified with the maximum transient error and the steady error between simulation and experiment within 5 %, which proves the effectiveness of the optimization.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"271 ","pages":"Article 126391"},"PeriodicalIF":6.1,"publicationDate":"2025-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143760293","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 investigation on the performance of a closed-wet cooling tower (CWCT) integrated into the underground exhaust air channel","authors":"Xu Zhou ,&nbsp;Xiaoling Cao ,&nbsp;Dongxu Wang ,&nbsp;Lang Wu ,&nbsp;Yanping Yuan ,&nbsp;Lin Huang ,&nbsp;Jiangyan Ma","doi":"10.1016/j.applthermaleng.2025.126368","DOIUrl":"10.1016/j.applthermaleng.2025.126368","url":null,"abstract":"<div><div>A closed-wet cooling tower (CWCT) integrated into an underground exhaust air channel is proposed in this paper. This design aims to harness the cooling capacity of exhaust air from underground buildings, thereby conserving space and enhancing overall space utilization in underground space. To elucidate the fundamental thermal characteristics of the CWCT, a numerical method was developed using COMSOL Multiphysics software to predict the heat and mass transfer processes within the tower. The reliability of this method was validated through experimental testing and also corroborated by two existing studies in the literature. Compared to conventional closed-wet cooling towers (CWCTs), the cooling performance of the CWCT is not significantly affected by the heat dissipation from nearby rocks. However, it demonstrates greater thermal efficiency than conventional ones. The thermal efficiency can be enhanced by adjusting the operating conditions, such as increasing the flow rate and inlet temperature of the cooling water, as well as the water spray density. However, it is important to note that the cooling efficiency only improves with an increase in water spray density. The sensitive analysis shows that the thermal efficiency and heat exchange capacity are most affected by water spray density, while the cooling efficiency is more affected by the cooling water mass flow rate. Therefore, adjusting the spray density might be the most recommended method for enhancing thermal performance. Under the current calculation conditions, adjusting the spray density can achieve a thermal efficiency of 30.77 % and a cooling efficiency of 48.57 %. Additionally, it can provide approximately 22.7 % of the cooling demand for the case building when the water spray density is set at 2.924 kg/(m²·s). Moreover, connecting multiple heat exchanger units can enhance thermal efficiency while simultaneously reducing cooling efficiency. Under the current calculation conditions, it is advisable to connect two units in series within the air channel. The heat exchange capacity can reach 14.8 kW, with a cooling efficiency of 32.2 %, thereby meeting more than 29 % of the cooling demand for the case building.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"271 ","pages":"Article 126368"},"PeriodicalIF":6.1,"publicationDate":"2025-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143760297","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}