Applied Thermal Engineering最新文献_第2页

Study on the heat transfer performance of phase change energy storage evacuated tubes enhanced with corrugated fins 波纹翅片强化相变储能真空管换热性能研究

IF 6.9 2区工程技术 Q2 ENERGY & FUELS

Applied Thermal Engineering

Pub Date : 2026-04-01 Epub Date: 2026-01-31 DOI: 10.1016/j.applthermaleng.2026.130064

Ao Mou , Xilian Han , Zhanxiang Qiao , Yimeng Hu , Xu Hong , Hongqiang Ma

To address the issues of low thermal conductivity and slow heat transfer rates in Phase Change Materials (PCM) within Energy Storage Evacuated Tube Solar Collectors (ES-ETSC), this study proposes a novel fin structure incorporating axial corrugated fins within the evacuated tubes. Through a combined experimental and numerical simulation approach, this structure was compared with a straight fin configuration. Single-factor and Response Surface Method (RSM) were employed to optimize the axial length, radial length-to-width ratio, and angle of the corrugated fins. Results indicate that compared to straight fins, corrugated fins increase the PCM's final temperature by 33 K and reduce complete liquefaction time by 2.93 h. Single-factor analysis reveals that axial length and radial length-to-width ratio are primary factors influencing heat transfer, while the deflection angle has a relatively minor effect. Through optimization of the multi-factor interactive response surface, the optimal structural parameter combination for the corrugated fins (fin height 1700 mm, length-to-width ratio 8:1, Angle 150.6°) was determined. Compared with the optimized rectangular fins (1700 mm, length-to-width ratio 4:2), the average heat release efficiency of the corrugated fin system has increased by 40.5%. By optimizing the key parameters of axial corrugated fins, this work significantly enhances PCM thermal conductivity and overall heat exchange efficiency in ES-ETSC, thereby providing an innovative design solution and a robust theoretical framework.

为了解决储能真空管太阳能集热器（ES-ETSC）相变材料（PCM）导热系数低和传热速率慢的问题，本研究提出了一种新型的翅片结构，在真空管内结合轴向波纹翅片。通过实验与数值模拟相结合的方法，将该结构与直鳍结构进行了比较。采用单因素法和响应面法对波纹翅片轴向长度、径向长宽比和角度进行了优化。结果表明，与直翅片相比，波纹翅片使PCM的最终温度提高了33 K，完全液化时间缩短了2.93 h。单因素分析表明，轴向长度和径向长宽比是影响PCM传热的主要因素，而偏转角的影响相对较小。通过多因素交互响应面优化，确定了波纹翅片的最优结构参数组合（翅片高度1700 mm，长宽比8:1，角度150.6°）。与优化后的矩形翅片（1700 mm，长宽比4:2）相比，波纹翅片系统的平均放热效率提高了40.5%。通过优化轴向波纹翅片的关键参数，本工作显著提高了ES-ETSC中PCM的导热系数和整体热交换效率，从而提供了一种创新的设计解决方案和强大的理论框架。

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引用次数: 0

Performance assessment of a photovoltaic/thermal heat pump coupled ground source heat pump hybrid system across five climate zones in China 中国5个气候区光伏/热热泵耦合地源热泵混合系统性能评价

IF 6.9 2区工程技术 Q2 ENERGY & FUELS

Applied Thermal Engineering

Pub Date : 2026-04-01 Epub Date: 2026-01-31 DOI: 10.1016/j.applthermaleng.2026.130069

Ziyu Xing , Rongji Xu , Qiang Xu , Hongbing Chen , Gaochao Li , Keming Xu , Xiang Li

To overcome the critical bottleneck of long-term soil thermal imbalance in conventional Ground Source Heat Pump (GSHP) applications, this study proposes a novel, universally applicable operational framework based on a Photovoltaic/Thermal Heat Pump and GSHP (PVTHP–GSHP) hybrid system. The core novelty of this work lies in the development of a unified Multi-Source Complementary Strategy (MSCS), which enables the system to flexibly switch between soil heat replenishment and dissipation modes, ensuring adaptability across diverse climates. Dynamic simulations were conducted in TRNSYS for five representative cities—Shenyang, Yinchuan, Shanghai, Kunming, and Guangzhou—covering China's five major climate zones over a 20-year lifecycle. Performance evaluation focused on soil temperature evolution, system energy consumption, Coefficient of Performance (COP), and economic feasibility. Results demonstrate that the proposed strategy significantly mitigates soil thermal degradation. In heating-dominated regions, the absolute value of the Thermal Imbalance Ratio (TIR) decreased by up to 23%, while in cooling-dominated regions, the average reduction was around 20%. Lifecycle energy consumption decreased by an average of 40%, and system COP improved by 25–54% compared with conventional GSHP systems. Economic assessment reveals payback periods ranging from 4.4 to 10 years, with Kunming achieving the optimal return. Ultimately, this research fills the knowledge gap regarding cross-regional system adaptability, offering a robust theoretical basis and a promising pathway for large-scale, clean, and efficient building energy applications in China.

为了克服传统地源热泵（GSHP）应用中土壤长期热不平衡的关键瓶颈，本研究提出了一种基于光伏/热热泵和地源热泵（PVTHP-GSHP）混合系统的新型、普遍适用的运行框架。这项工作的核心新颖之处在于开发了统一的多源互补策略（MSCS），使系统能够灵活地在土壤热补充和耗散模式之间切换，确保对不同气候的适应性。在TRNSYS中对沈阳、银川、上海、昆明和广州五个具有代表性的城市进行了为期20年的动态模拟，覆盖了中国五大气候带。性能评价侧重于土壤温度演变、系统能耗、性能系数（COP）和经济可行性。结果表明，该策略显著缓解了土壤热退化。在以供暖为主的地区，热平衡比（TIR）的绝对值下降了23%，而在以制冷为主的地区，平均下降了20%左右。与传统的地源热泵系统相比，该系统的生命周期能耗平均降低了40%，系统COP提高了25-54%。经济评价表明，投资回收期在4.4年至10年之间，昆明实现了最优回报。最终，本研究填补了关于跨区域系统适应性的知识空白，为中国大规模、清洁、高效的建筑能源应用提供了坚实的理论基础和有希望的途径。

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引用次数: 0

Reducing thermal stress and improving efficiency in HCPV cells using CFD-optimized pin-finned microchannel cooling 利用cfd优化的针鳍微通道冷却技术降低HCPV电池的热应力并提高效率

IF 6.9 2区工程技术 Q2 ENERGY & FUELS

Applied Thermal Engineering

Pub Date : 2026-04-01 Epub Date: 2026-02-10 DOI: 10.1016/j.applthermaleng.2026.130196

A. Santos, A. González, E. Castillo

High-concentration photovoltaic (HCPV) systems can achieve high electrical efficiencies, but their performance is constrained by the intense and spatially non-uniform thermal loads generated under high solar concentration. This work presents a three-dimensional conjugate heat-transfer analysis of microchannel cooling strategies for HCPV cells operating at

C R = 1000

, evaluating (i) pin-fin geometry, (ii) pin rotation, and (iii) differential flow distribution, together with Newtonian water and a shear-thinning nanofluid. The full multilayer GaInP/GaInAs/Ge assembly is explicitly resolved using fine-resolution finite-volume simulations, and the thermal model is validated against published experimental data. Pin-fin microchannels reduce maximum temperature difference by up to 11.9% and average temperatures by up to 9.68% relative to smooth channels. Differential flow allocation further decreases non-uniformity by up to 5.21%, while nanofluid rheology lowers peak-temperature differences by an additional 2%–3% at high flow rates. These improvements increase net electrical output to 37.75 W for the best-performing configuration. The resulting reduction in temperature gradients also decreases thermoelastic stress within the multilayer structure, with the optimized configuration lowering the maximum stress by up to 19.4%. An environmental assessment—based on representative operating conditions and carbon-pricing parameters—indicates annual CO

_{2}

reductions of up to 1.55% per m² and carbon-cost savings on the order of

4.5 \times 1 0^{4}

USD/(year m²). The results show that geometry-tailored microchannels combined with shear-dependent coolant rheology can reduce peak temperatures, temperature gradients, and associated stress levels in high-flux photovoltaic receivers.

高浓度光伏（HCPV）系统可以实现较高的电效率，但其性能受到高太阳能浓度下产生的强烈且空间不均匀热负荷的限制。本研究提出了在CR=1000下运行的HCPV电池的微通道冷却策略的三维共轭传热分析，评估了(i)针鳍几何形状，（ii）针旋转，（iii）微分流分布，以及牛顿水和剪切变薄纳米流体。使用精细分辨率有限体积模拟明确地解析了全多层GaInP/GaInAs/Ge组件，并根据已发表的实验数据验证了热模型。与光滑通道相比，鳍状微通道的最大温差降低了11.9%，平均温度降低了9.68%。不同的流动分配进一步降低了5.21%的不均匀性，而纳米流体流变学在高流速下可将峰值温差额外降低2%-3%。这些改进将净电输出增加到37.75 W，以实现最佳性能配置。温度梯度的减小也降低了多层结构内的热弹性应力，优化后的结构将最大应力降低了19.4%。基于代表性操作条件和碳定价参数的环境评估表明，每平方米每年可减少高达1.55%的二氧化碳排放，碳成本节约约为4.5×104美元/（年平方米）。结果表明，几何形状定制的微通道结合剪切依赖的冷却剂流变特性可以降低高通量光伏接收器的峰值温度、温度梯度和相关应力水平。

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引用次数: 0

Comprehensive structural parameter for thermal optimization of PCM composites under constant heat flux: Experiments and simulations 恒热流密度下PCM复合材料热优化的综合结构参数：实验与仿真

IF 6.9 2区工程技术 Q2 ENERGY & FUELS

Applied Thermal Engineering

Pub Date : 2026-04-01 Epub Date: 2026-02-03 DOI: 10.1016/j.applthermaleng.2026.130101

Yufeng Shuai , Chuan Zhang , Xusheng Hu , Siyuan He , Xiao-lu Gong

In this study, we focus on the comprehensive structural parameter A introduced and validated in our prior research. Five distinct metal foam samples using aluminum alloy AS7G through 3D printing were fabricated. The heating was maintained at a constant heat flux and positioned at various locations on the phase change material-metal foam composites (PCM composites). Our investigation encompasses both simulations and experiments, to explore the thermal behaviors of samples using parameter A under diverse heating conditions. The thermal performance of PCM composites is assessed with different indicators that we proposed. We examine the relation between the structural parameter A and the thermal performance and also the impact of gravity, sample size, heat flux, structural non-homogeneity and ambient temperature. This paper establishes the reliability of parameter A as a structural optimization criterion for metal foam. Furthermore, we find that if the heat transfer mode changes, the relation between the structural parameter and the thermal performance can be different. For conduction-dominated mode, lower parameter A structure shows better performance. For convection-dominated mode, higher parameter A structure improves performance. This may provide explanation for the existing debut regarding the influence of pore density. The study concludes with a comprehensive strategy for structural optimization of thermal performance of PCM composite based on all obtained results.

在本研究中，我们重点研究在我们之前的研究中引入并验证的综合结构参数A。采用铝合金AS7G，通过3D打印制作了5种不同的金属泡沫样品。在相变材料-金属泡沫复合材料（PCM）上，加热保持恒定的热流密度，并放置在不同的位置。我们的研究包括模拟和实验，以探索使用参数A的样品在不同加热条件下的热行为。采用我们提出的不同指标对PCM复合材料的热性能进行了评价。我们研究了结构参数A与热性能的关系，以及重力、样本量、热流密度、结构非均匀性和环境温度的影响。本文建立了参数A的可靠度作为泡沫金属结构优化准则。此外，我们发现，当换热方式改变时，结构参数与热性能之间的关系可能会有所不同。在电导主导模式下，A参数越低的结构性能越好。对于对流主导模式，更高的参数A结构可以提高性能。这可以解释目前关于孔隙密度影响的初步研究。在此基础上，提出了综合优化PCM复合材料热性能的结构策略。

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引用次数: 0

Experimental and modeling investigation of superheating, evaporation and non-uniform heating in microwave-heated liquids 微波加热液体过热、蒸发和不均匀加热的实验与模型研究

IF 6.9 2区工程技术 Q2 ENERGY & FUELS

Applied Thermal Engineering

Pub Date : 2026-04-01 Epub Date: 2026-02-07 DOI: 10.1016/j.applthermaleng.2026.130183

Arreerat Jiamprasertboon , Natdanai Saipan , Pongsakorn Wattanasit , Tanachat Eknapakul

Understanding heat and mass transfer during microwave heating is essential for predicting evaporation, superheating, and temperature non-uniformity in liquid systems. Here, we present a systematic experimental–modeling investigation of microwave heating in water, sucrose, and NaCl solutions over a range of concentrations and input powers. Bulk and surface temperatures were monitored in real time using thermocouples and infrared pyrometry, enabling direct assessment of temperature non-uniformity. Evaporation- and superheating-induced mass loss was quantified using pixel-tracking image analysis (PTIA) and validated gravimetrically, with an average deviation of 6.91 ± 4.42%. Material property variations were minor for sucrose solutions but pronounced for NaCl solutions, which exhibited substantial increases in electrical conductivity and dielectric loss. Sub-boiling COMSOL simulations incorporating solution-dependent dielectric properties, microwave power dissipation, and natural convection reproduce nearly uniform heating in water and sucrose (ΔT_uni = 0.37–0.51 °C) and pronounced surface-localized heating in NaCl solutions (ΔT_uni = 4.0–4.9 °C), associated with reduced microwave penetration depth. All solutions exhibit superheating, reaching temperatures up to ∼112 °C with measurable mass loss. A simplified lumped and multi-domain heat–mass transfer model is used to interpret the transition from uniform to non-uniform heating and the associated evaporation behavior. Overall, this work provides an experimentally grounded framework for interpreting microwave heating in liquids and improving the reproducibility of microwave-assisted thermal processes.

了解微波加热过程中的传热和传质对于预测液体系统中的蒸发、过热和温度不均匀性至关重要。在这里，我们提出了一个系统的实验模型研究微波加热的水，蔗糖和NaCl溶液在一定的浓度和输入功率范围内。使用热电偶和红外热分析法实时监测体温和表面温度，从而可以直接评估温度不均匀性。利用像素跟踪图像分析（PTIA）对蒸发和过热引起的质量损失进行量化，并进行重量验证，平均偏差为6.91±4.42%。蔗糖溶液的材料性质变化不大，但NaCl溶液的材料性质变化明显，其电导率和介电损耗显著增加。亚沸腾COMSOL模拟结合了溶液相关的介电特性、微波功率耗散和自然对流，再现了水和蔗糖（ΔTuni = 0.37-0.51°C）中几乎均匀的加热，以及NaCl溶液（ΔTuni = 4.0-4.9°C）中明显的表面局部加热，这与微波穿透深度的降低有关。所有溶液都表现出过热，温度高达~ 112°C，质量损失可测量。采用简化的集总多域热质传递模型解释了均匀加热到非均匀加热的转变及其相关的蒸发行为。总的来说，这项工作为解释液体中的微波加热和提高微波辅助热过程的可重复性提供了一个实验基础框架。

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引用次数: 0

Design and optimization of an agrivoltaic greenhouse integrated with a hybrid PV/T-EAHE system 结合PV/T-EAHE混合系统的农业温室设计与优化

IF 6.9 2区工程技术 Q2 ENERGY & FUELS

Applied Thermal Engineering

Pub Date : 2026-04-01 Epub Date: 2026-02-04 DOI: 10.1016/j.applthermaleng.2026.129798

Siavash Maniee, Mehdi Maerefat

This study presents the transient simulation of a greenhouse integrated with a hybrid photovoltaic/thermal (PV/T) and earth-to-air heat exchanger (EAHE) system in Tehran, aimed at determining the optimal design capacities of cooling/heating equipment and evaluating the indoor microclimate. The simulations were conducted in TRNSYS, with PV/T panels installed on the southern roof and the EAHE located beneath the cultivation surface to align with agrivoltaic design principles. The temporal variations of thermal and thermodynamic parameters—including air temperature, relative humidity, CO₂ concentration, and plant evapotranspiration—were analyzed for two representative days: January 12 (coldest) and July 1 (hottest), under four configurations: conventional, PV/T, EAHE, and PV/T-EAHE hybrid greenhouses. The results demonstrate that the design capacities of the fan-pad cooling and heating systems decrease by 19.6% and 15.9%, respectively, in the hybrid configuration relative to the baseline. The PV/T system contributes more significantly to summer performance enhancement, while the EAHE is more effective in winter. The hybrid configuration achieves an average 18% reduction in overall HVAC capacity. In summer, total daily water consumption decreases from 876 L (baseline) to 727 L (hybrid), representing a 17% reduction, while net fan-related electrical energy use drops by 49% compared to the traditional greenhouse. These findings confirm the technical feasibility and energy-saving potential of integrating PV/T and EAHE systems in greenhouse applications under semi-arid climatic conditions. In addition, validation against experimental data shows satisfactory agreement, with low RMSE values of air temperature (1.63–1.83 °C) and high R-Squared (0.91–0.96).

本研究介绍了德黑兰一个混合光伏/热（PV/T）和地对空热交换器（EAHE）系统的温室的瞬态模拟，旨在确定冷却/加热设备的最佳设计能力，并评估室内微气候。模拟在TRNSYS中进行，光伏/T面板安装在南屋顶，EAHE位于种植表面下方，以符合农业光伏设计原则。在常规温室、PV/T温室、EAHE温室和PV/T-EAHE混合温室4种配置下，分析了1月12日（最冷）和7月1日（最热）2个代表性日的气温、相对湿度、CO 2浓度和植物蒸散量的时间变化。结果表明，在混合动力配置下，风扇垫冷却和加热系统的设计能力相对于基线分别下降了19.6%和15.9%。PV/T系统对夏季性能提升的贡献更显著，而EAHE系统对冬季性能提升的效果更显著。混合配置使整体暖通空调容量平均减少18%。在夏季，每天的总用水量从876升（基线）减少到727升（混合），减少了17%，而与传统温室相比，与风扇相关的净电能消耗下降了49%。这些发现证实了在半干旱气候条件下，光伏/T和EAHE系统在温室应用中的技术可行性和节能潜力。此外，与实验数据的验证结果吻合良好，气温的RMSE值较低（1.63 ~ 1.83℃），r平方值较高（0.91 ~ 0.96）。

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引用次数: 0

Multiphysics topology optimization method for regenerative cooling channels integrating structural-thermal-hydraulic performance 综合结构-热工性能的蓄热冷却通道多物理场拓扑优化方法

IF 6.9 2区工程技术 Q2 ENERGY & FUELS

Applied Thermal Engineering

Pub Date : 2026-04-01 Epub Date: 2026-02-07 DOI: 10.1016/j.applthermaleng.2026.130175

Zheng Qiu , Shutian Liu , Quhao Li , Song Zhang , Qing Zhang

With the development of high-speed and lightweight aircraft, cooling channels must dissipate intense heat while maintaining structural integrity under severe thermo-mechanical loads. Current design methods mainly focus on thermal-hydraulic performance, often neglecting load-bearing capacity, which can lead to stress concentrations and premature failure. To overcome this limitation, this study proposes a multiphysics topology optimization framework that concurrently integrates structural stiffness, strength, thermal resistance, and flow resistance in cooling channel design. A density-based approach combines a multi-layer 2D conjugate heat transfer model with a projected 3D mechanical analysis, thus avoiding stiffness singularity in 2D channel analysis while enabling efficient evaluation of temperature, flow, compliance, and stress. Numerical examples under various design conditions demonstrate that incorporating load-bearing performance significantly alters channel layouts compared to thermal-hydraulic-only designs, eliminating stress-concentrating features. The optimized designs can increase stiffness by up to 27.41% and reduce maximum stress by 17.44%, while effectively managing thermal performance. These results validate the proposed method as a robust tool for designing cooling channels that meet combined structural-thermal-hydraulic requirements, providing an effective method to improve high-performance aerospace thermal management systems.

随着飞机高速、轻量化的发展，冷却通道必须在承受剧烈热机械载荷的情况下，既能散热，又能保持结构的完整性。现有的设计方法主要关注热工性能，而忽略了承载能力，容易导致应力集中和过早破坏。为了克服这一限制，本研究提出了一种多物理场拓扑优化框架，该框架同时集成了冷却通道设计中的结构刚度、强度、热阻和流动阻力。基于密度的方法将多层二维共轭传热模型与投影三维力学分析相结合，从而避免了二维通道分析中的刚度奇异性，同时能够有效地评估温度、流动、顺应性和应力。在各种设计条件下的数值示例表明，与仅采用热水力设计相比，结合承载性能显著改变了通道布局，消除了应力集中特征。优化后的设计可将刚度提高27.41%，最大应力降低17.44%，同时有效地控制热性能。这些结果验证了所提出的方法是设计满足结构-热-液压组合要求的冷却通道的强大工具，为改进高性能航空航天热管理系统提供了有效方法。

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引用次数: 0

Improved temperature uniformity and fast charging of high energy density Li-ion battery module via two-phase immersion cooling 采用两相浸没冷却提高了高能量密度锂离子电池模块的温度均匀性和快速充电性能

IF 6.9 2区工程技术 Q2 ENERGY & FUELS

Applied Thermal Engineering

Pub Date : 2026-04-01 Epub Date: 2026-02-05 DOI: 10.1016/j.applthermaleng.2026.130105

Danish Akbal Kureshi, Rakesh Nandan, Mihir Kumar Das

Nickel-Cobalt-Aluminum (NCA) lithium-ion (Li-ion) batteries provide high energy density and prolonged life, making them ideal for high-performance electric vehicles and aerospace applications. However, this chemistry leads to severe heat generation during fast charging and discharging without an effective thermal management system, leading to degradation and pose safety risks. Further, two-phase immersion cooling is recognized for its high heat transfer coefficients and low wall superheat. Based on these facts, the present study investigates the application of N-pentane as a dielectric coolant for two-phase immersion cooling of a 5S3P Li-ion battery module. The analysis focuses on two-phase heat transfer performance, surface temperature variation, and temperature uniformity of the battery in the module under different C-rates of charging and discharging. Results show that N-pentane immersion cooling effectively limits battery temperatures in the module below 40 °C with a peak reduction of 15.86 °C at 1C charging over natural convection cooling. At 2C discharging, it reduces the temperature non-homogeneity of 3.87 °C, nearly a tenfold improvement over natural convection cooling. Also, immersion cooling maintained acceptable battery temperature even under 2C fast charging, confirming its suitability for high-rate operation. During cyclic loading, the naturally cooled battery module exceeded the safety limit after the second cycle, while immersion cooling sustained repeated 1C–1C and 1C–2C cycles within safe limits. Further, high-speed bubble visualization shows an inverse trend between bubble departure diameter and nucleation frequency. Overall, the study shows that two-phase immersion cooling effectively manages the thermal challenges in NCA battery modules.

镍钴铝（NCA）锂离子（Li-ion）电池提供高能量密度和长寿命，使其成为高性能电动汽车和航空航天应用的理想选择。然而，如果没有有效的热管理系统，这种化学反应会导致在快速充放电过程中产生严重的热量，从而导致降解并构成安全风险。此外，两相浸没冷却因其高传热系数和低壁过热度而得到认可。基于这些事实，本研究研究了正戊烷作为介质冷却剂在5S3P锂离子电池模块两相浸没冷却中的应用。重点分析了不同充放电倍率下模块内电池的两相传热性能、表面温度变化和温度均匀性。结果表明，与自然对流冷却相比，正戊烷浸没冷却有效地将模块中的电池温度限制在40°C以下，在1C充电时峰值降低15.86°C。在2C放电时，它降低了3.87°C的温度不均匀性，比自然对流冷却提高了近10倍。此外，浸没式冷却即使在2C快速充电下也能保持可接受的电池温度，证实了其适合高倍率运行。在循环加载过程中，自然冷却的电池模块在第二次循环后超过安全极限，而浸没冷却的电池模块则在安全范围内持续重复1C-1C和1C-2C循环。此外，高速气泡可视化显示气泡偏离直径与成核频率呈反比趋势。总体而言，该研究表明，两相浸入式冷却有效地管理了NCA电池模块的热挑战。

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引用次数: 0

Study on thermophysical properties and performance enhancement of novel quaternary molten salt for thermal energy storage 新型储热用季铵盐热物性及增强性能研究

IF 6.9 2区工程技术 Q2 ENERGY & FUELS

Applied Thermal Engineering

Pub Date : 2026-04-01 Epub Date: 2026-02-03 DOI: 10.1016/j.applthermaleng.2026.130122

Yuanyuan Wang, Yue Wang, Yuanwei Lu, Yuting Wu, Cancan Zhang

Molten salts are commonly used as heat transfer and thermal storage media in CSP systems. However, conventional molten salts may have drawbacks such as high melting points, narrow operating temperature ranges, and low thermal conductivity, which limit the overall system efficiency. In this work, a novel quaternary nitrate-nitrite molten salt is developed, featuring low melting point, wide operating temperature range, high thermal conductivity, and low cost. The melting point of the quaternary salt (composed of 41.4wt%KNO₃–32.7wt%NaNO₂–7.9wt%KNO₂-18 wt% Ca(NO₃)₂·4H₂O) is 96.6 °C, and the decomposition temperature is 622.3 °C. The quaternary salt shows an average specific heat capacity of 1.58 J∙g⁻¹∙K⁻¹ and an average thermal conductivity of 0.574 W∙m⁻¹∙K⁻¹ in the liquid state. The long-term thermal stability testing (including 1000 h of high-temperature aging and 500 thermal shock cycles) indicates that the thermal properties of this quaternary salt undergo certain changes, primarily attributed to the conversion of NO₂⁻ to NO₃⁻ within the molten salt. Using precursor decomposition method, MgO-molten salt nanocomposites and Al₂O₃-molten salt nanocomposites were synthesized in situ. In terms of both cost-effectiveness and performance enhancement, the Al₂O₃ additive underperforms compared to the MgO additive. Adding 0.5 wt% MgO to quaternary salt can increase its specific heat capacity by 20.4%, enhance its thermal conductivity by 55.5%, and simultaneously reduce its sensible heat storage cost by 18.3%. The novelty of this work is the design and systematic evaluation of novel molten salt, focusing on its long-term stability, performance enhancement mechanism, and economic viability, thereby offering the promising candidate materials for TES applications.

在CSP系统中，熔盐通常用作传热和储热介质。然而，传统的熔盐可能存在熔点高、工作温度范围窄、导热系数低等缺点，从而限制了系统的整体效率。本文研制了一种新型的季铵盐-亚硝酸盐熔盐，具有熔点低、工作温度范围宽、导热系数高、成本低等特点。季铵盐（41.4wt% KNO3-32.7wt % NaNO2-7.9wt %KNO2-18 wt% Ca(NO3)2·4H2O）的熔点为96.6℃，分解温度为622.3℃。季盐液相平均比热容为1.58 J∙g−1∙K−1，平均导热系数为0.574 W∙m−1∙K−1。长期热稳定性测试（包括1000 h高温老化和500次热冲击循环）表明，该季盐的热性能发生了一定的变化，主要原因是熔盐中NO2−向NO3−的转化。采用前驱体分解法，原位合成了mgo -熔盐纳米复合材料和al2o3 -熔盐纳米复合材料。在成本效益和性能增强方面，Al2O3添加剂不如MgO添加剂。在季盐中加入0.5 wt%的MgO，其比热容提高20.4%，导热系数提高55.5%，显热成本降低18.3%。本工作的新颖之处在于新型熔盐的设计和系统评估，重点关注其长期稳定性、性能增强机制和经济可行性，从而为TES应用提供有前途的候选材料。

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引用次数: 0

Experimental and numerical study on the flow and heat transfer performance of standard and asymmetric oscillating double-wall cooling configurations 标准和非对称振荡双壁冷却结构流动和换热性能的实验与数值研究

IF 6.9 2区工程技术 Q2 ENERGY & FUELS

Applied Thermal Engineering

Pub Date : 2026-04-01 Epub Date: 2026-02-25 DOI: 10.1016/j.applthermaleng.2026.130435

Sai Xie, Xiaojun Fan, Jiao Wang, Guangyao Yu, Cunjin Zhang, Junlin Cheng, Yu Sun

Traditional impingement jets in double-wall structures often cause non-uniform temperature fields, inducing localized thermal stresses and shortening blade life. To address this critical issue, this study proposes a unique self-excited oscillating double-wall cooling design. Adopting a method combining numerical simulations (based on the RANS k-ω SST turbulence model) with infrared thermal imaging experiments, comprehensively evaluate how Reynolds number, nozzle quantity, geometric size, and structural asymmetry modulate the cooling effectiveness. The results indicate that the self-excited oscillating jet significantly enhances wall temperature uniformity while preserving heat transfer intensity relative to traditional impingement nozzles. Notably, oscillating jets are maintained across an extensive Reynolds number range (500 to 150,000). The oscillation frequency of the nozzle will increase, as the Reynolds number increases, while the maximum oscillation Angle will decrease. While a higher nozzle count reduces the area of localized high-Nusselt number zones, it substantially improves overall heat transfer uniformity. Optimizing nozzle size is found to markedly boost the average Nusselt number. Moreover, asymmetric nozzles exhibit superior thermal performance compared to symmetrical designs. Under the same working conditions, the configuration (inner block width = 1.25D) achieves a comprehensive heat transfer coefficient 2.25 times that of the symmetric configuration. Specifically, the 1.25D nozzle attains a temperature reduction of 4.6 K (1.28%) and 3.8 K (1.1%) compared to the impingement and standard oscillating nozzles, respectively.

传统的双壁结构冲击射流往往导致温度场不均匀，产生局部热应力，缩短叶片寿命。为了解决这一关键问题，本研究提出了一种独特的自激振荡双壁冷却设计。采用数值模拟（基于RANS k-ω SST湍流模型）与红外热成像实验相结合的方法，综合评价雷诺数、喷嘴数量、几何尺寸、结构不对称对冷却效果的调节作用。结果表明，与传统的撞击式喷嘴相比，自激振荡射流在保持换热强度的同时显著提高了壁面温度均匀性。值得注意的是，振荡射流保持在广泛的雷诺数范围内（500至150,000）。随着雷诺数的增加，喷嘴的振荡频率增加，而最大振荡角减小。虽然较高的喷嘴数量减少了局部高努塞尔数区域的面积，但它大大提高了整体传热均匀性。优化喷嘴尺寸可以显著提高平均努塞尔数。此外，与对称设计相比，非对称喷嘴具有更好的热性能。在相同工况下，内块宽度= 1.25D的配置综合换热系数是对称配置的2.25倍。具体来说，与撞击式和标准振荡式喷嘴相比，1.25D喷嘴的温度分别降低了4.6 K（1.28%）和3.8 K（1.1%）。

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引用次数: 0