Energy Conversion and Management最新文献_第6页

Towards sustainable and explainable dual-fuel diesel engine modeling:a SHAP-Based evaluation of Ammonia, Biogas, and hydrogen combustion dynamics 迈向可持续和可解释的双燃料柴油发动机建模：基于shap的氨，沼气和氢燃烧动力学评估

IF 10.9 1区工程技术 Q1 ENERGY & FUELS

Energy Conversion and Management

Pub Date : 2026-01-07 DOI: 10.1016/j.enconman.2025.121014

Bhaskor Jyoti Bora , Prabhakar Sharma

Gaseous fuels are gaining increasing attention for power generation in internal combustion engines due to their cleaner combustion and potential for decarbonization. This study investigates the performance, combustion, and emission characteristics of a dual-fuel diesel engine operated with hydrogen, biogas, and ammonia as primary fuels, with diesel serving as the pilot fuel. At full engine load, the brake thermal efficiencies for hydrogen, biogas, and ammonia were 25.11 %, 19.25 %, and 17.33 %, respectively, compared to 23.11 % in diesel-only mode. The corresponding liquid fuel replacement ratios reached 79 %, 76.1 %, and 69 %, demonstrating significant potential for fossil fuel reduction. Combustion analysis revealed longer ignition delays for biogas (46.25 %) and ammonia (56.25 %) compared to hydrogen. Emission profiles indicated that hydrogen produced the lowest CO and HC emissions but exhibited higher NOx levels than the other fuels. In parallel, supervised machine learning models—Linear Regression, Extreme Gradient Boosting, and Gradient Boosted Regression Trees (GBRT)—were developed to predict brake thermal efficiency, liquid fuel substitution, peak cylinder pressure, and emissions (CO, HC, NOx). Tree-based ensemble models outperformed the linear baseline, effectively capturing the nonlinear influence of engine load and fuel lower heating value on engine responses. Gradient Boosted Regression Tree achieved the highest accuracy for brake thermal efficiencies (R² = 0.9933) and CO (R² = 0.9965), while Extreme Gradient Boosting was most accurate for peak cylinder pressure (R2 = 0.9898). SHAP-based explainable Artificial Intelligence analysis identified engine load as the dominant factor governing performance and emissions. Overall, the combined experimental–Machine Learning framework establishes hydrogen as a highly promising dual-fuel candidate and demonstrates Gradient Boosted Regression Trees’s strong capability for predictive optimization of dual-fuel combustion systems.

气体燃料由于其清洁燃烧和脱碳的潜力而越来越受到内燃机发电的关注。本文研究了以氢气、沼气和氨为主要燃料，柴油为中试燃料的双燃料柴油机的性能、燃烧和排放特性。在发动机满载时，氢气、沼气和氨气的制动热效率分别为25.11%、19.25%和17.33%，而纯柴油模式的制动热效率为23.11%。相应的液体燃料替代率分别达到79%、76.1%和69%，显示出化石燃料减少的巨大潜力。燃烧分析表明，与氢气相比，沼气（46.25%）和氨气（56.25%）的点火延迟时间更长。排放曲线表明，氢气产生的CO和HC排放量最低，但NOx含量高于其他燃料。同时，有监督的机器学习模型——线性回归、极端梯度增强和梯度增强回归树（GBRT）——被开发出来，用于预测制动热效率、液体燃料替代、峰值气缸压力和排放（CO、HC、NOx）。基于树的集成模型优于线性基线，有效捕获了发动机负载和燃油低热值对发动机响应的非线性影响。梯度增强回归树在制动热效率（R2 = 0.9933）和CO （R2 = 0.9965）方面的准确度最高，而极端梯度增强在汽缸峰值压力方面的准确度最高（R2 = 0.9898）。基于shap的可解释人工智能分析将发动机负载确定为控制性能和排放的主要因素。总体而言，结合实验-机器学习框架确立了氢作为极具前景的双燃料候选燃料，并证明了梯度增强回归树在双燃料燃烧系统预测优化方面的强大能力。

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引用次数: 0

A multi-objective optimization framework for analyzing thermal resilience under power outage and varying climatic conditions 停电和气候变化条件下热弹性分析的多目标优化框架

IF 10.9 1区工程技术 Q1 ENERGY & FUELS

Energy Conversion and Management

Pub Date : 2026-01-07 DOI: 10.1016/j.enconman.2025.121013

Ahmad Shoaib Amiri , Michael Jemtrud , Daniel Chung

As extreme weather events are becoming more severe and frequent, there is a growing risk to occupants’ health and well-being, which requires investigating and improving thermal resilience. To address the limitations of the current methods for quantifying passive survivability, this study applies a novel methodology that integrates building energy simulation, multi-objective optimization, and thermal resilience under extreme climatic conditions and power outage scenarios. The method was applied to a case study building located in Montreal, Canada, to evaluate how six design variables—orientation, thermal mass, solar absorptance, glazing U-value, glazing solar transmittance, and overhang shading influence thermal resilience, energy consumption, and thermal comfort across historic and projected climates. Mathematical models were developed to correlate the variables to summer and winter passive survivability. The research determined that for the studied scenarios, solar absorptance is the design variable with the highest impact on passive survivability, followed by thermal mass and glazing transmittance. The results show that the optimized envelope configurations increased the summer passive survivability of the Gym up to 17 h, compared to 6 h in winter, highlighting strong seasonal asymmetry. Pareto-optimal solutions achieving maximum summer survivability exhibited whole-building EUI values between 99–105 kWh/m² and discomfort ranging from 656–794 h.

随着极端天气事件变得越来越严重和频繁，居住者的健康和福祉面临越来越大的风险，这需要调查和提高热弹性。为了解决目前量化被动生存能力方法的局限性，本研究采用了一种新的方法，该方法将建筑能源模拟、多目标优化和极端气候条件和停电情景下的热弹性相结合。该方法被应用于加拿大蒙特利尔的一个建筑案例研究中，以评估六个设计变量——朝向、热质量、太阳吸收率、玻璃u值、玻璃太阳透射率和悬垂遮阳如何影响历史和预测气候下的热弹性、能源消耗和热舒适性。建立了与夏季和冬季被动生存能力相关的数学模型。研究确定，在研究的场景中，太阳能吸收率是对被动生存能力影响最大的设计变量，其次是热质量和玻璃透过率。结果表明，与冬季的6小时相比，优化后的围护结构使体育馆夏季的被动生存能力提高了17小时，突出了强烈的季节不对称性。获得最大夏季生存能力的帕累托最优方案显示，整个建筑的EUI值在99-105 kWh/m2之间，不适度在656-794 h之间。

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引用次数: 0

Performance assessment of a rotary thermomagnetic motor for energy harvesting applications 能量收集用旋转热磁电机的性能评估

IF 10.9 1区工程技术 Q1 ENERGY & FUELS

Energy Conversion and Management

Pub Date : 2026-01-07 DOI: 10.1016/j.enconman.2026.121037

Clara E.L. Silva , Marcos S. Tadim , Marcelo A. Câmara , Hugo C.C. Michel , Carmela M.P. Braga , Paulo V. Trevizoli

Thermomagnetic motors are a promising solid-state energy harvesting technology capable of converting low-grade waste heat into usable mechanical energy. Their integration with thermal and energy systems enables cogeneration applications that can enhance the overall efficiency of industrial processes. This work presents an experimental performance assessment of a rotary thermomagnetic motor prototype, which utilizes a rotor with gadolinium fins. The prototype was tested under configurations featuring two and four magnetic field regions. A series of experiments were conducted to evaluate torque and rotational speed across varying cold sink and heat source temperatures, as well as different cold and warm fluid flow rates. These measurements were used to construct characteristic curves for torque and output power as a function of the rotational speed. The prototype demonstrated performance improvements over existing designs, achieving a maximum rotational speed of 348.5 RPM, a peak torque of 2.3 N m, and a maximum output power of 4.6 W. These results offer insights into how the number of magnetic-field regions, the working-fluid temperature and flow rate influence motor performance. They further represent an important contribution to the development of more efficient thermomagnetic energy-harvesting systems.

热磁电机是一种很有前途的固态能量收集技术，能够将低品位的废热转化为可用的机械能。它们与热能和能源系统的集成使热电联产应用能够提高工业过程的整体效率。这项工作提出了一个实验性能评估的旋转热磁电机原型，它利用一个转子与钆鳍。原型机在两个和四个磁场区域的配置下进行了测试。进行了一系列实验，以评估不同冷槽和热源温度下的扭矩和转速，以及不同的冷和热流体流速。这些测量被用来构建扭矩和输出功率作为转速函数的特征曲线。与现有设计相比，原型机的性能得到了改进，最大转速为348.5 RPM，峰值扭矩为2.3 N m，最大输出功率为4.6 W。这些结果为了解磁场区域的数量、工作流体的温度和流量如何影响电机性能提供了见解。它们进一步为开发更有效的热磁能量收集系统做出了重要贡献。

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引用次数: 0

Simulation and experimental study of heat transfer characteristics of spray-cooled heat exchanger 喷雾冷却换热器换热特性的模拟与实验研究

IF 10.9 1区工程技术 Q1 ENERGY & FUELS

Energy Conversion and Management

Pub Date : 2026-01-07 DOI: 10.1016/j.enconman.2026.121036

Zongsheng Zhu , Jianhui Li , Jianyu Liu , Xinli Lv , Shiguang Wang , Bin Liu

This paper combines spray cooling technology with shell and tube heat exchangers, revealing the influence of spray parameters on heat transfer characteristics through numerical simulation and experimental studies. The simulation and experimental processes set the inlet water temperature in the heat transfer tubes to 18°C, while the refrigerant evaporation temperature inside the shell is set to 12°C. R32 is used as the refrigerant, and the heat transfer tubes are arranged in a three-layer cross pattern. The dynamic behavior of the liquid film, heat transfer mechanisms, and heat transfer characteristics under single/double nozzle spray modes at the top are analyzed through simulation. Under single nozzle mode, as the spray velocity increases, the average heat flux density in the first row of heat transfer tubes rises from 3,124 W/m² (5 m/s) to 13,721 W/m² (15 m/s), with the effective heat flux density in the spray zone remaining above 21,000 W/m², reaching a maximum of 24,330 W/m². Double nozzles effectively increase the spray area, maintaining the effective heat flux density in the spray zone above 23,000 W/m² under study conditions, with a peak value of 24,900 W/m². A dual-nozzle visual spray cooling experimental setup was constructed for preliminary experimental research, showing that the heat flux density in the spray zone increases with increasing spray pressure, reaching a maximum of 11,560 W/m² at 0.9 MPa.

本文将喷雾冷却技术与管壳式换热器相结合，通过数值模拟和实验研究揭示了喷雾参数对换热特性的影响。模拟和实验流程将换热管进水温度设置为18℃，壳体内制冷剂蒸发温度设置为12℃。采用R32作为制冷剂，换热管呈三层交叉布置。通过仿真分析了顶部单/双喷嘴喷射方式下液膜的动态行为、传热机理及传热特性。单喷嘴模式下，随着喷射速度的增加，第一排换热管的平均热流密度从3124 W/m2 （5 m/s）上升到13721 W/m2 (15 m/s)，喷雾区有效热流密度保持在21000 W/m2以上，最大达到24330 W/m2。双喷嘴有效地增加了喷雾面积，在研究条件下，喷雾区有效热流密度保持在23,000 W/m2以上，峰值为24,900 W/m2。搭建了双喷嘴视觉喷雾冷却实验装置进行初步实验研究，结果表明：随着喷雾压力的增大，喷雾区热流密度增大，在0.9 MPa时达到最大值11,560 W/m2。

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引用次数: 0

Energy, exergy, and economic analysis and optimization of a novel CCHP system integrating low-temperature SOFC and high-temperature PEMFC with transcritical CO2 cycle and elastocaloric cooler 结合低温SOFC和高温PEMFC、跨临界CO2循环和弹性热冷却器的新型热电联产系统的能源、火用和经济分析与优化

IF 10.9 1区工程技术 Q1 ENERGY & FUELS

Energy Conversion and Management

Pub Date : 2026-01-06 DOI: 10.1016/j.enconman.2025.121017

Ma Yu , Chen Yubin , Gao Huaibin , Wei Meng , Zhang Chuanwei

To meet diverse energy needs and improve fuel cell (FC) system efficiency, a novel combined cooling, heating, and power (CCHP) system is proposed. The system integrates four subsystems: low-temperature SOFC (LTSOFC), high-temperature PEMFC (HTPEMFC), transcritical CO₂ (TCO₂) cycle and elastocaloric cooler (ECC). In this configuration, the LTSOFC serves as both a power generator and fuel supplier for the HTPEMFC while also providing heat to other subsystems. The system’s energy, exergy, and economic (3E) performance is evaluated and compared with other SOFC-based systems, highlighting its superior performance. Under typical conditions, the system achieves energy and exergy efficiencies of 78.1 % and 68.8 %, outperforming the traditional SOFC-PEMFC system by 22.0 % and 12.8 %, respectively. The system produces a total electric power of 366.3 kW and levelized cost of 0.0495 $·kWh⁻¹. Then, sensitivity analyses are performed to assess the key parameters influence on the 3E performance, such as the fuel utilization factor, recirculation ratio and other critical subsystem parameters. Optimization using artificial neural network and genetic algorithm results in enhancements in energy and exergy efficiency by 10.8 % and 8.9 %, respectively, and a reduction in the levelized cost of energy by 6.1 %. This study not only provides a comprehensive thermodynamic and economic analysis of the system but also highlights its great potential for practical applications in FC-based CCHP systems.

为了满足燃料电池（FC）系统多样化的能源需求，提高系统效率，提出了一种新型的冷热电联产（CCHP）系统。该系统集成了四个子系统：低温SOFC （LTSOFC）、高温PEMFC （HTPEMFC）、跨临界CO2 （TCO2）循环和弹性热量冷却器（ECC）。在这种配置中，LTSOFC既是HTPEMFC的发电机和燃料供应商，同时也为其他子系统提供热量。该系统的能源、能源和经济（3E）性能进行了评估，并与其他基于sofc的系统进行了比较，突出了其优越的性能。在典型条件下，该系统的能量和火用效率分别为78.1%和68.8%，分别比传统的SOFC-PEMFC系统高22.0%和12.8%。系统总发电量366.3 kW，平准化成本0.0495美元·kWh−1。然后进行敏感性分析，评估燃油利用系数、再循环比等关键子系统参数对3E性能的影响。利用人工神经网络和遗传算法进行优化，能源效率和火用效率分别提高10.8%和8.9%，能源平准化成本降低6.1%。本研究不仅对该系统进行了全面的热力学和经济分析，而且强调了其在基于fc的CCHP系统中的实际应用潜力。

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引用次数: 0

Beyond oscillating-airfoil theory: a novel spinning-airfoil model for lift-based VAWT aerodynamics 超越振荡翼型理论：基于升力的VAWT空气动力学的新型旋转翼型模型

IF 10.9 1区工程技术 Q1 ENERGY & FUELS

Energy Conversion and Management

Pub Date : 2026-01-06 DOI: 10.1016/j.enconman.2025.120966

Mohammad Ghafouri Varzaneh , Fatemeh Yousefi Far , Amir Zanj

Oscillating airfoil models (OAMs) have been widely employed in various applications to analyze flow structures and dynamic stall phenomena. Owing to their kinematic similarity and extensive prior research, these models have also been adopted in Darrieus turbine studies. However, existing OAMs fail to accurately capture the velocity field, flow curvature, and blade–wake interactions in such turbines. To address these shortcomings, this study introduces a new kinematic model, the Spinning Airfoil Model (SAM), which improves upon existing OAMs by refining their pitching and surging functions and incorporating an additional plunging motion. Based on the proposed kinematic model, a CFD model was developed to evaluate its aerodynamic performance compared to a benchmark model and two OAM patterns. Simulation results show that SAM accurately reproduces Darrieus turbine behavior with superior numerical performance. Compared to the benchmark model, it predicts the instantaneous thrust coefficient with a determination factor (

R^{2}

) of

99.60 %

and the mean thrust coefficient with a relative error of 1.38% over a full cycle. SAM converges in approximately one-sixth of the benchmark time, using 5.3 times smaller domain and 3.6 times fewer mesh elements. By embedding the turbine’s key parameters into the three motion functions, SAM provides a straightforward tool for sensitivity analysis and deeper insight into flow structures and vortex dynamics. It also provides a foundation for defining Darrieus-specific dimensionless parameters to classify performance metrics and support comparative studies under consistent conditions. Moreover, its flexible kinematic configurations enable new approaches in numerical and experimental modeling of Darrieus turbines.

振荡翼型模型（OAMs）被广泛应用于分析流动结构和动态失速现象。由于它们的运动相似性和广泛的先前研究，这些模型也被采用在达雷尔斯涡轮机的研究中。然而，现有的OAMs无法准确捕捉这种涡轮中的速度场、流动曲率和叶片-尾迹相互作用。为了解决这些缺点，本研究引入了一种新的运动学模型，即旋转翼型模型（SAM），该模型通过改进现有的OAMs，改进其俯仰和澎湃功能，并加入额外的俯冲运动。基于所提出的运动学模型，建立了CFD模型，并与基准模型和两种OAM模式进行了气动性能评估。仿真结果表明，该方法能较好地再现达瑞乌斯水轮机的特性，并具有较好的数值性能。与基准模型相比，该模型预测全周期瞬时推力系数的决定因子R2为99.60%，平均推力系数的相对误差为1.38%。SAM在大约六分之一的基准时间内收敛，使用5.3倍小的域和3.6倍少的网格元素。通过将涡轮的关键参数嵌入到三个运动函数中，SAM为灵敏度分析和更深入地了解流动结构和涡旋动力学提供了一个简单的工具。它还为定义特定于达里厄斯的无量纲参数提供了基础，以对性能指标进行分类，并支持在一致条件下的比较研究。此外，其灵活的运动配置，使新的方法在数值和实验建模的达瑞厄斯涡轮机。

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引用次数: 0

Investigation of energy dissipation mechanisms and unsteady flow characteristics of a cooling pump based on sweeping jet inflow 基于扫流射流的冷却泵耗散机理及非定常流动特性研究

IF 10.9 1区工程技术 Q1 ENERGY & FUELS

Energy Conversion and Management

Pub Date : 2026-01-06 DOI: 10.1016/j.enconman.2025.120959

Hao Chang , Guo Tang , Ling Zhou , Guangjie Peng , Weidong Shi , Rong Huang

The cooling pump plays a crucial role in the conversion efficiency and operational safety of the solar thermal utilization system. Traditional cooling pumps employ a high-velocity jet that directly impacts the impeller, causing localized pressure drops and heightened impeller vibration. To overcome these limitations, this study proposes a novel cooling pump that generates periodically sweeping jet upon the impeller inlet. By combining the Plackett-Burman test with the Weighted Latin Hypercube Sampling method, the influence of fluidic oscillator nozzle parameters on hydraulic performance and the optimal geometric configuration were obtained. Numerical simulations were conducted using ANSYS Fluent, and experimental studies indicate that the efficiency is 13.05 % higher than that of the original model. The energy balance analysis was also introduced to investigate energy dissipation. The turbulent kinetic energy production term dominates total energy loss, with the impeller and jet oscillator contributing more significantly. Adopting the fluidic oscillator structure significantly reduces total energy loss. As the water temperature increases from 25 °C to 80 °C, the energy loss decreases and the sweeping period is extends. At 80 °C, the fluidic oscillator nozzle suppresses high-frequency impeller inlet vibrations, reducing the dimensionless average instantaneous frequency of the seventh intrinsic mode function component by 16.67 % relative to the original model (80 °C), and by 6.25 % relative to the optimized model (25 °C). This study offers valuable insights into enhancing the performance and reliability of cooling pumps.

冷却泵对太阳能热利用系统的转换效率和运行安全起着至关重要的作用。传统的冷却泵采用高速射流直接冲击叶轮，造成局部压降和叶轮振动加剧。为了克服这些限制，本研究提出了一种新型的冷却泵，在叶轮进口产生周期性的扫射射流。通过Plackett-Burman试验和加权拉丁超立方抽样方法相结合，得到了射流振荡器喷嘴参数对水力性能的影响和最优几何构型。利用ANSYS Fluent进行了数值模拟，实验研究表明，该模型的效率比原模型提高了13.05%。同时引入能量平衡分析来研究能量耗散。湍流动能产生项主导着总能量损失，其中叶轮和射流振子贡献更显著。采用流体振荡器结构，大大降低了总能量损失。水温从25℃升高到80℃，能量损失减小，清扫周期延长。在80°C时，射流振荡器喷嘴抑制了高频叶轮进口振动，相对于原始模型（80°C），第七个本征模态函数分量的无量纲平均瞬时频率降低了16.67%，相对于优化模型（25°C），降低了6.25%。这项研究为提高冷却泵的性能和可靠性提供了有价值的见解。

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引用次数: 0

Reducing the environmental impact and cost of ultra-low frequency vibrational energy harvesters based on magnetic levitation 降低基于磁悬浮的超低频振动能量采集器的环境影响和成本

IF 10.9 1区工程技术 Q1 ENERGY & FUELS

Energy Conversion and Management

Pub Date : 2026-01-06 DOI: 10.1016/j.enconman.2025.121028

I. Royo-Silvestre , J. Gómez-Hurtado , J.J. Beato-López , D. Gandia , E. Garaio , C. Gómez-Polo

Vibration energy harvesting is a technology that can harvest energy from environmental vibrations to power sensors and actuators, replacing batteries and avoiding extensive wiring in remote applications such as wireless sensor networks or infrastructure monitoring. Commercial devices successfully operate at low frequency, but some challenges remain to be solved. On one hand, the advantages over batteries depend on the actual environmental impact and cost of the harvester itself, both features hindered by the use of rare earth magnets. On the other hand, operation under ultra-low frequency vibrations is problematic even for laboratory prototypes. In this work, one-degree-of-freedom magnetic levitation-based energy harvesters are analyzed for ultra-low frequency vertical vibrations. Strategies for decreasing the resonant frequency and replacing rare earths for ferrite magnets are discussed. A prototype incorporating ferrite magnets is built and tested, achieving a resonant frequency of 2.8 Hz (the lowest for a portable harvester of this kind). In addition, different housing materials are compared to reduce friction and reliability, introducing 3D-printed resin housings as a promising alternative. The obtained results are compared with those of previously reported devices published in the literature in terms of environmental impact and cost, including LCAs (life cycle assessment) of the permanent magnets used in the prototypes, concluding that ferrite magnets can be successfully implemented in this kind of devices. The use of ferrites instead of NdFeB reduces the environmental impact of the fixed magnet by at least 20 %, and decreases its cost by 50 %.

振动能量收集是一种技术，可以从环境振动中收集能量，为传感器和执行器供电，取代电池，避免在无线传感器网络或基础设施监控等远程应用中大量布线。商用设备已经成功地在低频下工作，但仍有一些挑战有待解决。一方面，相对于电池的优势取决于收割机本身的实际环境影响和成本，这两个特点都受到稀土磁铁使用的阻碍。另一方面，超低频率振动下的操作，即使是实验室的原型也是有问题的。在这项工作中，对基于一自由度磁悬浮的能量采集器进行了超低频垂直振动分析。讨论了降低谐振频率和稀土替代铁氧体磁体的策略。一个包含铁氧体磁铁的原型被建造和测试，实现了2.8赫兹的谐振频率（这类便携式收割机的最低频率）。此外，不同的外壳材料进行比较，以减少摩擦和可靠性，引入3d打印树脂外壳作为一个有前途的替代方案。将获得的结果与先前在文献中发表的设备在环境影响和成本方面进行了比较，包括原型中使用的永磁体的LCAs（生命周期评估），得出铁氧体磁体可以成功实现在此类设备中的结论。使用铁氧体代替钕铁硼，固定磁体对环境的影响至少降低了20%，成本降低了50%。

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引用次数: 0

Heat transfer and thermal storage characteristics in sludge-based phase change composites 污泥基相变复合材料的传热和储热特性

IF 10.9 1区工程技术 Q1 ENERGY & FUELS

Energy Conversion and Management

Pub Date : 2026-01-06 DOI: 10.1016/j.enconman.2025.121030

Yaxuan Xiong , Zeling Jiang , Aitonglu Zhang , Xiangyao Qian , Yuting Wu , Yanqi Zhao

This study numerically investigates the heat transfer and thermal storage performance of phase change composites composed of sewage sludge incineration ash and

KN O_{3}

using COMSOL Multiphysics. A macroscopic solid–liquid phase change model is established to analyze how skeleton particle size (50, 100, 200, and 300 mesh) influences phase transition behavior and temperature distribution. Results demonstrate that smaller particles enhance specific surface area, reduce thermal resistance, and improve heat transfer, leading to an earlier and more uniform phase change. Compared to the 50-mesh sample, the 300-mesh sample achieved reductions of 40.9 % in phase change completion time and 64.6 % in thermal stabilization time. At the microscale, a porous skeleton model generated via the Quartet Structure Generation Set method reveals that the porous skeleton extends the melting time of the phase change material by 17.65 % relative to pure potassium nitrate, while improving temperature uniformity. The time required for the phase change material within the pores to reach a stable temperature increased by 28.95 % compared to pure phase change material. These findings clarify the dual role of porous structures in regulating heat transfer and storage, providing key insights for material optimization in thermal energy storage applications. Furthermore, with a low thermal storage cost of 5.33 $/MJ and total carbon emissions of 847.93 kg/t, the composite proves to be a more competitive candidate than conventional skeleton materials.

采用COMSOL Multiphysics对污泥焚烧灰与KNO3组成的相变复合材料的换热储热性能进行了数值研究。建立宏观固液相变模型，分析骨架粒径（50、100、200和300目）对相变行为和温度分布的影响。结果表明，颗粒越小，比表面积越大，热阻越小，传热越好，相变越早，相变越均匀。与50目样品相比，300目样品的相变完成时间减少了40.9%，热稳定时间减少了64.6%。在微观尺度上，通过四重奏结构生成集方法生成的多孔骨架模型表明，相对于纯硝酸钾，多孔骨架使相变材料的熔化时间延长了17.65%，同时提高了温度均匀性。相变材料在孔隙内达到稳定温度所需的时间比纯相变材料提高了28.95%。这些发现阐明了多孔结构在调节传热和储存方面的双重作用，为热能储存应用中的材料优化提供了关键见解。此外，该复合材料的储热成本较低，为5.33美元/MJ，总碳排放量为847.93 kg/t，比传统骨架材料更具竞争力。

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引用次数: 0

Ultra-efficient solar-to-electric conversion via hierarchical thermoelectric energy cascading: A multi-stage hybrid system with synergistic thermal utilization and pareto-optimal performance 通过分层热电能量级联的超高效太阳能-电力转换：具有协同热利用和帕累托最优性能的多级混合系统

IF 10.9 1区工程技术 Q1 ENERGY & FUELS

Energy Conversion and Management

Pub Date : 2026-01-05 DOI: 10.1016/j.enconman.2025.120999

Mingjing Lei , Xiaokuan You , Kang Li , Soheil Mohtaram

The pursuit of ultra-efficient solar energy conversion requires overcoming the inherent thermodynamic irreversibilities present in conventional systems. This study introduces a transformative hybrid architecture that integrates a dual-stage Alkali Metal Thermoelectric Converter with a two-stage thermoelectric generator, designed to synergistically utilize both high-temperature and mid-temperature thermal energy. A detailed analytical model is developed to simulate the coupled thermodynamic, electrochemical, and radiative processes within the fully solar-driven system. Parametric analyses evaluate the effects of solar concentration ratio, intermediate temperature, and electrical current density on overall performance. A multi-objective optimization framework based on Pareto optimality is employed to simultaneously maximize thermal efficiency and power output per unit aperture area. The optimized system achieves a peak thermal efficiency of 29.2 percent at a solar concentration ratio of 1450, along with a power output of 292 kW per square meter. These values represent improvements of 30.91 percent in efficiency and 43.11 percent in power output relative to a non-hybrid Alkali Metal Thermoelectric Converter. The optimization results reveal new synergistic interactions, in which the mid-temperature waste heat released from the converter’s condenser (400–800 K) is effectively recovered by the two-stage thermoelectric generator, substantially reducing exergy destruction. This work represents a new comprehensive integration and co-optimization of multi-stage Alkali Metal Thermoelectric Converter and multi-stage thermoelectric generator technologies within a unified solar-thermal framework. By mitigating dominant sources of entropy generation, the proposed architecture surpasses the performance ceiling of existing solar-thermal energy conversion systems and establishes a new design pathway for scalable, high-temperature, and statically operated concentrated solar power technologies.

追求超高效的太阳能转换需要克服传统系统中固有的热力学不可逆性。本研究介绍了一种变革性混合架构，该架构集成了双级碱金属热电转换器和两级热电发电机，旨在协同利用高温和中温热能。详细的分析模型是开发模拟耦合热力学，电化学和辐射过程在全太阳能驱动系统。参数分析评估了太阳能集中比、中间温度和电流密度对整体性能的影响。采用基于Pareto最优的多目标优化框架，使单位孔径面积热效率和功率输出同时最大化。优化后的系统在太阳能集中比为1450时达到29.2%的峰值热效率，每平方米输出功率为292千瓦。这些数值表明，与非混合式碱金属热电转换器相比，效率提高了30.91%，功率输出提高了43.11%。优化结果显示了新的协同作用，其中转炉冷凝器释放的中温余热（400-800 K）被两级热电发电机有效回收，大大减少了火用破坏。这项工作代表了在统一的光热框架内，多级碱金属热电转换器和多级热电发生器技术的一种新的综合集成和协同优化。通过减少熵产生的主要来源，所提出的架构超越了现有太阳能热能转换系统的性能上限，并为可扩展、高温和静态操作的聚光太阳能发电技术建立了新的设计途径。

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引用次数: 0