Case Studies in Thermal Engineering最新文献_第4页

A comprehensive analysis of flow and heat transfer performance in a novel Tesla valve microchannel 一种新型特斯拉阀微通道的流动和传热性能综合分析

IF 6.4 2区工程技术 Q1 THERMODYNAMICS

Case Studies in Thermal Engineering

Pub Date : 2026-01-10 DOI: 10.1016/j.csite.2026.107670

Ying Yin , Yunxin Zhu , Dexin Zhang , Yan Li , Liang Gong

High integration of high-performance chips has led to considerable heat generation, making efficient and stable heat dissipation within the chips extremely important. In this paper, a novel microchannel structure based on the Tesla valve is proposed to dissipate the heat generated by the high heat flux density in the chips. The numerical simulations are then performed using the standard k-ε turbulence model to explore how the number of valve stages, valve core shapes, structural parameters, and arrangements affect the flow and heat transfer performance of the microchannel. The results show that the microchannel with 12 valve stages exhibits the best performance. Compared to the rectangular fin (RF) type microchannel, the heat transfer performance in Tesla valve microchannels can be significantly enhanced, where the increased performance evaluation criterion (PEC) for reverse flow is superior to that for forward flow. The optimal shape of the Tesla valve core is an ellipse, whose PEC can be increased by up to 20.23 % compared with the RF microchannel. More importantly, the increasing arrangement of the valve structure along the flow direction can optimally balance flow resistance and heat transfer, resulting in enhanced overall performance. These results can provide new insights into efficient heat dissipation in electronic devices.

高性能芯片的高集成度导致了相当大的热量产生，使得芯片内高效稳定的散热变得极其重要。本文提出了一种基于特斯拉阀的新型微通道结构，用于散热芯片内部高热流密度产生的热量。采用标准k-ε湍流模型进行了数值模拟，探讨了阀级数、阀芯形状、结构参数和布置对微通道流动和传热性能的影响。结果表明，配置12阀级的微通道性能最佳。与矩形翅片（RF）型微通道相比，特斯拉阀微通道的换热性能可以得到显著提高，其中，反向流动时增加的性能评价标准（PEC）优于正向流动时。特斯拉阀芯的最优形状为椭圆，与射频微通道相比，其PEC可提高20.23%。更重要的是，阀门结构沿流动方向的增加布置可以最佳地平衡流动阻力和传热，从而提高整体性能。这些结果可以为电子器件的高效散热提供新的见解。

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引用次数: 0

Experimental investigation on low temperature heat source with a pumpless gravity-driven closed loop thermosyphon organic Rankine cycle 无泵重力驱动闭环热虹吸有机朗肯循环低温热源实验研究

IF 6.4 2区工程技术 Q1 THERMODYNAMICS

Case Studies in Thermal Engineering

Pub Date : 2026-01-10 DOI: 10.1016/j.csite.2026.107672

Samittisak Plaikaew, Thanit Swasdisevi, Jirawan Tiansuwan

In this study, a pumpless gravity-driven Organic Rankine Cycle (PORC) system was developed and experimentally tested for low-temperature heat recovery applications. The system utilized a modified scroll expander, originally designed for automotive air conditioning, and operated entirely via natural circulation, without a mechanical pump. The effects of refrigerant charge, heat source temperature, and resistive electrical load were investigated to evaluate system behavior and power generation efficiency. Results revealed that stable operation was achieved with a refrigerant charge between 2.1–2.3 kg, heat-source temperatures of 40–60 °C, and a system height of 2.8–3.1 m. The maximum work output of the expander reached 18.44 W, while electrical power output peaked at 0.80 W under optimal conditions. The scroll expander isentropic efficiency ranged from 30 to 86 %. A positive, approximately linear correlation was observed between system height and work output within the tested range. Although theoretical and experimental efficiencies diverged significantly—highlighting mechanical and electrical losses—the study confirmed the technical feasibility of pumpless ORC systems. Although the output is modest, it is comparable to other small-scale ORC systems operating at similar source temperatures, demonstrating comparable efficiency without a mechanical pump. These findings support the application of gravity-driven ORC systems for power production in space-constrained and off-grid environments using low-grade thermal energy sources.

在这项研究中，开发了一种无泵重力驱动的有机朗肯循环（PORC）系统，并对其进行了低温热回收应用的实验测试。该系统采用了一种改良的涡旋式膨胀器，最初是为汽车空调设计的，完全通过自然循环运行，不需要机械泵。研究了制冷剂充注量、热源温度和电阻性电负荷对系统性能和发电效率的影响。结果表明，当制冷剂充注量为2.1 ~ 2.3 kg，热源温度为40 ~ 60℃，系统高度为2.8 ~ 3.1 m时，系统运行稳定。在最优条件下，膨胀机的最大功输出为18.44 W，电功率输出最高为0.80 W。涡旋膨胀机等熵效率为30% ~ 86%。在测试范围内，观察到系统高度与功输出之间呈正的近似线性相关。尽管理论和实验效率存在显著差异，特别是机械和电气损失，但该研究证实了无泵ORC系统在技术上的可行性。虽然输出量不大，但与其他在相似源温度下运行的小型ORC系统相当，在没有机械泵的情况下也显示出相当的效率。这些发现支持了重力驱动的ORC系统在空间受限和离网环境下使用低品位热能发电的应用。

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引用次数: 0

Synergistic Heat Transfer Enhancement and Drag Reduction in Spiral Wound Tubes via Ultrasonic Excitation 超声激励下螺旋缠绕管的增效传热和减阻

IF 6.8 2区工程技术 Q1 THERMODYNAMICS

Case Studies in Thermal Engineering

Pub Date : 2026-01-10 DOI: 10.1016/j.csite.2026.107675

Zhao Chen, Fengjun Wang, Mingbao Zhang, Zhijian Wang, Chulin Yu

This study innovatively couples ultrasonic active control technology with the structural characteristics of spiral-wound tube heat exchangers, proposing a novel multi-physical field synergistic approach for heat transfer enhancement. A tube bundle-acoustic field interaction experimental system was established to study the effects of the intensity (133,333 W/m2, 233,333 W/m2, 333,333 W/m2) and frequency (21 kHz, 25 kHz, 28 kHz) of ultrasonic waves, the installation position of transducers (inlet-only, outlet-only, simultaneous inlet-outlet), as well as the influence of installing different numbers of transducers (1–4) under different working conditions on the comprehensive heat exchange drag reduction capacity of the tube bundle were studied. The results demonstrate that ultrasonic technology provides dual enhancements: heat transfer intensification and drag reduction. The experimental results demonstrate an inverse correlation between ultrasonic frequency and enhancement magnitude. When subjected to 21 kHz excitation, the Nusselt number exhibits a 33.8% enhancement while the friction factor shows a 13.66% reduction compared to baseline conditions. This synergistic effect yields 40.86% improvement in thermal-hydraulic performance. When transducers are installed at both the inlet and outlet, optimal heat transfer performance is achieved. Compared to conditions without ultrasound, the Nusselt number increases by 72%. Comparing the installation of different numbers of transducers at the inlet of the heat exchange tube, the optimal heat transfer enhancement effect was achieved when three ultrasonic transducers were installed. The Nusselt number increased by up to 88%, and the Performance Evaluation Coefficient (PEC) reached its maximum value of 3.36.

本研究创新性地将超声主动控制技术与螺旋缠绕管换热器的结构特点结合起来，提出了一种新的多物理场协同强化换热方法。管bundle-acoustic交互建立了实验系统研究领域的影响强度(133333 W / m2, 233333 W / m2, 333333 W / m2)和频率(21 kHz, 25 kHz, 28千赫)的超声波传感器的安装位置(inlet-only outlet-only,同时进出),并研究了不同工况下安装不同数量换能器（1-4个）对管束综合换热减阻能力的影响。结果表明，超声技术提供了双重增强：传热强化和阻力减少。实验结果表明，超声频率与增强幅度呈负相关。当受到21 kHz激励时，与基线条件相比，努塞尔数增加了33.8%，而摩擦系数减少了13.66%。这种协同效应使热工性能提高了40.86%。当换能器安装在入口和出口时，可以实现最佳的传热性能。与没有超声的情况相比，努塞尔数增加了72%。对比换热管进口安装不同数量换能器的效果，安装3个换能器的换热效果最佳。Nusselt数增加了88%，性能评价系数（PEC）达到最大值3.36。

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引用次数: 0

An extended narrow-band k-distribution method for gas radiation characteristics based on a hybrid deep neural network 基于混合深度神经网络的气体辐射特性扩展窄带k分布方法

IF 6.8 2区工程技术 Q1 THERMODYNAMICS

Case Studies in Thermal Engineering

Pub Date : 2026-01-10 DOI: 10.1016/j.csite.2026.107694

Bao-Hai Gao, Hao Sun, Ming-Jian He, Ya-Tao Ren, Jun-Yan Liu, Hong Qi

The calculation of gas radiative properties is a fundamental problem in numerous fields such as combustion diagnostics, aerospace engineering, and atmospheric remote sensing. Developing computational models that combine both high efficiency and accuracy has become a shared goal and central challenge in this field. To this end, this study integrates the physical mechanisms of gas radiation with data-driven approaches, proposing an Extended Narrow-Band k-distribution (ENBK) method based on a Hybrid Deep Neural Network (HDNN). The ENBK method extends the high spectral-resolution k-distribution absorption coefficients of multiple single components into mixed-gas multi-band k-distribution absorption coefficients through probability density function convolution, thereby enabling the calculation of radiative properties of inhomogeneous mixed gases across multiple spectral resolutions. Meanwhile, a narrow-band k-distribution absorption coefficient database for H2O and CO2 was constructed using the NBK method, covering a wide range of thermodynamic states with high spectral resolution (5 cm-1), which serves as training data for a designed deep neural network that combines fully connected and transposed convolutional layers. The computational accuracy of ENBK and HDNN was evaluated against the Line-by-Line (LBL) and NBK method for several typical engineering cases. The results demonstrate that ENBK maintains high accuracy in both mixing multiple gas components and extending spectral bands, with average relative errors of less than 0.5% in calculated narrow- and wide-band radiation intensity and transmissivity compared to the LBL benchmark method. Furthermore, the trained HDNN model significantly reduces database storage requirements (saving over 90% of memory) while enabling rapid and accurate prediction of narrow-band k-distribution absorption coefficients under given thermodynamic conditions.

气体辐射特性的计算在燃烧诊断、航空航天工程和大气遥感等许多领域都是一个基本问题。开发既高效又准确的计算模型已成为该领域的共同目标和核心挑战。为此，本研究将气体辐射的物理机制与数据驱动方法相结合，提出了一种基于混合深度神经网络（HDNN）的扩展窄带k分布（ENBK）方法。ENBK方法通过概率密度函数卷积，将多个单一组分的高光谱分辨率k分布吸收系数扩展为混合气体的多波段k分布吸收系数，从而可以跨多光谱分辨率计算非均匀混合气体的辐射特性。同时，采用NBK方法构建了H2O和CO2窄带k分布吸收系数数据库，该数据库涵盖了大范围的热力学状态，具有高光谱分辨率（5 cm-1），作为设计的全连接层和转置卷积层相结合的深度神经网络的训练数据。针对几个典型工程实例，对比逐行（Line-by-Line， LBL）和逐行（NBK）方法，对ENBK和HDNN的计算精度进行了评价。结果表明，ENBK在混合多种气体组分和扩展光谱波段方面都保持了较高的精度，与LBL基准方法相比，计算的窄带和宽带辐射强度和透射率的平均相对误差小于0.5%。此外，训练后的HDNN模型显著降低了数据库存储需求（节省超过90%的内存），同时能够在给定热力学条件下快速准确地预测窄带k分布吸收系数。

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引用次数: 0

Experimental study on the transient response of a solar micropower thermoelectric generator using wet-fabric evaporative cooling 湿织物蒸发冷却太阳能微功率热电发电机瞬态响应的实验研究

IF 6.4 2区工程技术 Q1 THERMODYNAMICS

Case Studies in Thermal Engineering

Pub Date : 2026-01-10 DOI: 10.1016/j.csite.2026.107698

Joffin Jose Ponnore , Hazim Moria

Efficient cooling of the shadowed side of concentrated solar thermoelectric generators (STEGs) remains a major challenge, particularly at the micropower scale, where active cooling is not practical because its power consumption can exceed the power generated. Passive cooling using a simple heat sink is inadequate to maintain the necessary temperature difference. This challenge becomes even more critical when the application targets only the transient impulse period of the TEG (i.e. immediately after exposure to a heat source before output declines to steady state). Hence, this study experimentally investigates the transient response of a solar-driven micropower TEG equipped with an innovative ultrathin self-wicking passive fabric cooling system and compares its performance with a conventional finned heat sink. The fabric, coated with a hydrophilic layer, passively draws water to its surface, forming a thin film that enhances cooling through evaporation. Using a parabolic dish collector to focus sunlight, key parameters including hot- and cold-side temperatures, generated current, heat losses, and conversion efficiency were measured at 1-s intervals from initial exposure through steady-state operation. The results demonstrate that, while the hot-side temperature stabilizes near 92 °C in both cases, the wet fabric keeps the cold side over 10 °C cooler than the heatsink, sustaining a larger temperature gradient. This translates into around 14 % higher peak current in the transient stage and 147 % greater steady-state current. Heat-loss analysis further confirmed that, although the heatsink rejected more sensible heat, the wet membrane achieved superior performance through latent evaporative cooling. Overall, the study establishes wet-fabric cooling as a highly effective passive alternative to conventional heatsinks for solar-driven TEGs under natural convection condition. By leveraging evaporative cooling, it enhances both impulse power and long-term output, offering strong potential for powering portable devices, off-grid systems, and IoT applications that rely on intermittent bursts of energy.

对聚光太阳能热电发电机（steg）的阴暗面进行有效冷却仍然是一个主要挑战，特别是在微功率规模下，主动冷却是不现实的，因为它的功耗可能超过所产生的功率。被动冷却使用一个简单的散热器是不足以维持必要的温差。当应用程序仅针对TEG的瞬态脉冲周期（即在输出下降到稳态之前立即暴露于热源）时，这一挑战变得更加关键。因此，本研究通过实验研究了配备创新的超薄自吸被动织物冷却系统的太阳能驱动微功率TEG的瞬态响应，并将其性能与传统的翅片散热器进行了比较。这种织物上涂有一层亲水层，可以被动地将水吸到表面，形成一层薄膜，通过蒸发来增强冷却效果。利用抛物面盘集热器聚焦太阳光，从初始暴露到稳态运行，每隔一秒测量一次关键参数，包括冷热侧温度、产生的电流、热损失和转换效率。结果表明，在两种情况下，热侧温度稳定在92°C附近，湿织物使冷侧温度比散热器低10°C以上，保持更大的温度梯度。这意味着瞬态阶段的峰值电流高14%，稳态电流高147%。热损失分析进一步证实，虽然散热器拒绝了更多的显热，但湿膜通过潜在蒸发冷却获得了更好的性能。总体而言，该研究确立了湿织物冷却作为自然对流条件下太阳能驱动teg的传统散热器的高效被动替代方案。通过利用蒸发冷却，它提高了脉冲功率和长期输出，为依赖间歇性能量爆发的便携式设备、离网系统和物联网应用提供了强大的潜力。

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引用次数: 0

Experimental investigation on the effect of compression ratio on detonation combustion characteristics of active pre-chamber engine 压缩比对主动预燃室发动机爆震燃烧特性影响的实验研究

IF 6.4 2区工程技术 Q1 THERMODYNAMICS

Case Studies in Thermal Engineering

Pub Date : 2026-01-10 DOI: 10.1016/j.csite.2025.107628

Jingxun Yang , Fangxi Xie , Xiaoping Li , Beiping Jiang , Zhaohui Jin , Bo shen , Yu Liu

Turbulent Jet Ignition (TJI) engines show promising potential for enhancing engine efficiency. However, they differ significantly from conventional spark ignition engines in terms of in-cylinder combustion modes, rendering traditional detonation evaluation methods inadequate for accurately assessing TJI engine detonation states. This study introduces two new metrics: Before θPmax (the crank angle corresponding to peak cylinder pressure) Detonation Energy (BPDE) and After θPmax Detonation Energy (APDE) to characterize the knock behavior of TJI engines. Through analyzing the knock characteristics of the TJI engine under different compression ratio (CR), the author found that when the CR increased from 13 to 17 and the ignition angle was set to 12°CA bTDC, the engine's AMAPO increased by 0.55 MPa, and TDE increased by 0.8 MPa·°CA. However, when the CR reached 19, although TDE increased by 0.192 MPa·°CA, AMAPO decreased by 0.145 MPa. Two newly introduced metrics explain this phenomenon: when the CR increased from 17 to 19, ABPDE rose by 62.3 % while AAPDE decreased by 15.5 %. Knock energy primarily shifted to ABPDE, causing AAPDE to decline and resulting in the decrease of AMAPO. Additionally, no super-knock phenomena were observed at a CR of 19 and 70 % load. The knock frequency distribution of TJI engines at different CRs was analyzed using Fast Fourier Transform (FFT). Statistical probability distribution (PD) and cumulative distribution (CD) were employed to estimate changes in Maximum Amplitude Pressure Oscillation (MAPO) across varying CRs. The knock characteristics of TJI engines were further detailed.

紊流喷射点火（TJI）发动机在提高发动机效率方面具有广阔的应用前景。然而，它们与传统的火花点火发动机在缸内燃烧方式上有很大的不同，使得传统的爆震评估方法无法准确评估TJI发动机的爆震状态。本文引入了θPmax前爆轰能（BPDE）和θPmax后爆轰能（APDE）两个新的指标来表征TJI发动机的爆震行为。通过分析不同压缩比（CR）下TJI发动机的爆震特性，发现当CR从13增加到17，点火角设置为12°CA时，发动机的AMAPO增加0.55 MPa， TDE增加0.8 MPa·°CA。当CR达到19时，TDE增加0.192 MPa·°CA，而AMAPO减少0.145 MPa。两个新引入的指标解释了这一现象：当CR从17增加到19时，ABPDE上升了62.3%，而AAPDE下降了15.5%。Knock能量主要向ABPDE转移，导致AAPDE下降，导致AMAPO减少。此外，在CR为19和70%负荷时，未观察到超爆震现象。采用快速傅立叶变换（FFT）分析了发动机在不同临界转速下的爆震频率分布。采用统计概率分布（PD）和累积分布（CD）估计最大振幅压力振荡（MAPO）在不同cr间的变化。进一步详细分析了TJI发动机的爆震特性。

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引用次数: 0

Numerical Simulation of Grooved Channel Heat Transfer Enhancement: Structural Optimization and Pulsating Flow 沟槽通道强化传热的数值模拟：结构优化与脉动流动

IF 6.8 2区工程技术 Q1 THERMODYNAMICS

Case Studies in Thermal Engineering

Pub Date : 2026-01-10 DOI: 10.1016/j.csite.2026.107685

Jiachen Feng, Tieyu Gao, Weifeng Wang, Zhiheng Xue, Ke Yang

This paper investigates the heat transfer performance of a rectangular grooved channel heat exchanger under various conditions through numerical simulation, followed by structural optimization to develop a more efficient rectangular grooved heat exchanger. Geometric optimization of the rectangular grooved channel under steady-state flow conditions (Re = 1200) was performed using Particle swarm optimization (PSO) and Bayesian optimization (BO) algorithm. Three parameters were optimized: groove starting point (x2), groove depth (y3), and groove ending point (x4). The objective function was the performance evaluation criterion (PECs). The optimized structure achieved a 2.9% improvement in the performance evaluation criterion compared to the pre-optimization design. Because the baseline is an already enhanced grooved geometry rather than a smooth duct, the observed improvement is relatively limited; the study’s main contribution is a transparent and transferable optimization methodology. The optimized rectangular groove is shallower, enabling more thorough fluid contact with the wall surface and facilitating heat transfer. When pulsating flow was applied to the optimized geometry, the PECs reached its maximum value of 1.65 when the pulsation frequency matched the natural frequency.

本文通过数值模拟研究了矩形沟槽换热器在各种工况下的换热性能，并对其进行了结构优化，以开发出更高效的矩形沟槽换热器。采用粒子群算法（PSO）和贝叶斯优化算法（BO）对稳态流条件下（Re = 1200）矩形沟槽通道进行几何优化。优化3个参数：沟槽起点（x2）、沟槽深度（y3）和沟槽终点（x4）。目标函数为绩效评价准则（PECs）。与优化前相比，优化后的结构在性能评价指标上提高了2.9%。由于基线是已经增强的沟槽几何形状，而不是光滑的管道，因此观察到的改善相对有限；该研究的主要贡献是一个透明和可转移的优化方法。优化后的矩形槽较浅，使流体与壁面接触更彻底，便于传热。当脉动流作用于优化后的几何结构时，当脉动频率与固有频率匹配时，PECs达到最大值1.65。

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引用次数: 0

Broadband high-temperature multilayer pyramid-shaped metamaterial thermal absorber for thermophotovoltaic applications 用于热光伏应用的宽带高温多层金字塔形超材料吸热器

IF 6.4 2区工程技术 Q1 THERMODYNAMICS

Case Studies in Thermal Engineering

Pub Date : 2026-01-10 DOI: 10.1016/j.csite.2026.107697

Bibekananda Nath, Ahmed Zubair

A broadband, thermally stable absorber is essential for thermophotovoltaic (TPV) systems to simultaneously convert solar and industrial waste heat into usable energy to meet growing power demands. Here, we proposed an ingenious polarization-independent truncated pyramid-shaped symmetric multilayer metamaterial absorber in a metal–insulator–metal–insulator (MIMI) architecture with almost complete absorption over a broad wavelength range. A total of six structures (W/AlN, Mo/AlN, Ta/AlN, Rh/MgO, Rh/SiO₂, Re/BN) were designed, and the materials were selected based on their lattice matching to prevent delamination at interfaces between layers. The absorption mechanism was studied using the finite difference time domain (FDTD) method, and the structure was optimized through a brute force design approach, which illustrates a best average absorption of 98.2% till 4000 nm and 97.73% till 5072 nm wavelength for the W/AlN structure with metal and dielectric thicknesses of 60 nm and 17.5 nm, respectively. Moreover, W/AlN structure exhibits over 96% average absorption up to 50° incident angles irrespective of polarizations. The thermal stability was evaluated using the finite element method (FEM) by determining von Mises stress at elevated temperatures. Thermal analysis revealed that only W/AlN can withstand around 1700 K temperature and 1500 times the incident power before permanent deformation. A temperature-dependent Drude–Lorentz model was used to further analyze the effect of absorption on the optical performance of the highly absorptive and thermally stable W/AlN structure. Additionally, we determined the effect of the concentration factor and the operating temperature on the absorber’s performance by considering the emission loss of the heated absorber. This research has enormous potential in high-temperature applications like thermal energy storage systems, photodetectors, and sensors.

宽带、热稳定的吸收体对于热光伏（TPV）系统来说是必不可少的，它可以同时将太阳能和工业废热转化为可用的能源，以满足不断增长的电力需求。在这里，我们提出了一种巧妙的极化无关的截断金字塔形对称多层超材料吸收器，在金属-绝缘体-金属-绝缘体（MIMI）结构中，在宽波长范围内几乎完全吸收。设计了W/AlN、Mo/AlN、Ta/AlN、Rh/MgO、Rh/SiO2、Re/BN等6种结构，并根据其晶格匹配度选择材料，防止层间界面发生分层。采用时域有限差分法（FDTD）研究了吸收机理，并采用暴力设计方法对结构进行了优化。结果表明，当金属厚度为60 nm、电介质厚度为17.5 nm时，W/AlN结构在4000 nm和5072 nm波长处的平均吸收率分别为98.2%和97.73%。此外，W/AlN结构在50°入射角范围内的平均吸收率超过96%，与极化无关。采用有限元法测定高温下的von Mises应力，评价材料的热稳定性。热分析表明，只有W/AlN能够承受1700 K左右的温度和1500倍的入射功率才会发生永久变形。采用温度相关的德鲁德-洛伦兹模型进一步分析了吸收对高吸收率和热稳定性W/AlN结构光学性能的影响。此外，我们还考虑了加热吸收器的排放损失，确定了浓度因子和工作温度对吸收器性能的影响。这项研究在高温应用方面具有巨大的潜力，如热能储存系统、光电探测器和传感器。

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引用次数: 0

Coordinated control of a solid oxide fuel cell system based on Newton-Raphson and active disturbance rejection control algorithm 基于牛顿-拉夫逊和自抗扰控制算法的固体氧化物燃料电池系统协调控制

IF 6.4 2区工程技术 Q1 THERMODYNAMICS

Case Studies in Thermal Engineering

Pub Date : 2026-01-10 DOI: 10.1016/j.csite.2026.107682

Yuanli Liu, Si Yang, Bing Yang, Ying Zhong, Yiyu Chen, Zhongmin Wan, Xi Chen

Solid oxide fuel cells (SOFCs) are a pivotal technology for mitigating energy shortages, where precise thermal management and power regulation are essential. Their performance and safety critically depend on operating temperature and load-following capability. However, conventional control strategies are hampered by sluggish dynamic response, inadequate regulation under high-power or large-load variations, and reliance on time-consuming trial-and-error parameter tuning, which collectively degrade performance. The study develops an advanced Newton-Raphson-based optimizer active disturbance rejection control (NRBO-ADRC) strategy to address these limitations. A validated SOFC system model and a subsequent dual-loop multivariable control framework are established. This framework characterizes the relationship between operating temperature and a fixed polarization voltage (0.85 V) under varying power demands, enabling coordinated control of target power, temperature, and voltage through air and fuel flow regulation. Evaluated against conventional ADRC and PID-ADRC under step-change and realistic random disturbances, the proposed strategy demonstrates superior performance. At 60 kW target power, adjustment times are reduced by 57.5 % and 46.2 % compared to PID and ADRC, respectively, with overshoot limited to 0.5 %, which is corresponding to reductions of 58.3 % and 44.4 %. Under disturbances, the power control elative error of NRBO-ADRC reduce 30.9 % and 12.2 % than PID and ADRC, and the relative error of NRBO-ADRC is 1.37 % and 1.31 % to temperature and voltage control, which is decreased 41 % and 44 % than PID, and dropped 25 % and 27 % than ADRC. The NRBO-ADRC strategy significantly enhances dynamic response, overshoot suppression, and robustness, providing an effective reference for multivariable control in high-power SOFC systems and contributing to advances in distributed power generation.

固体氧化物燃料电池（sofc）是缓解能源短缺的关键技术，其中精确的热管理和功率调节是必不可少的。它们的性能和安全性主要取决于工作温度和负载跟踪能力。然而，传统的控制策略受到动态响应缓慢，高功率或大负载变化下的调节不足以及依赖耗时的试错参数调整的阻碍，这些都降低了性能。该研究开发了一种先进的基于牛顿-拉斐尔的优化自抗扰控制（NRBO-ADRC）策略来解决这些限制。建立了经过验证的SOFC系统模型和后续的双环多变量控制框架。该框架描述了在不同功率需求下工作温度与固定极化电压（0.85 V）之间的关系，通过空气和燃料流量调节实现对目标功率、温度和电压的协调控制。在阶跃变化和现实随机干扰下，与传统自抗扰和pid自抗扰进行了比较，结果表明该策略具有较好的性能。在60 kW的目标功率下，与PID和ADRC相比，调整时间分别减少了57.5%和46.2%，超调量限制在0.5%，相应的减少了58.3%和44.4%。在扰动条件下，NRBO-ADRC的功率控制相对误差比PID和ADRC减小了30.9%和12.2%，对温度和电压控制的相对误差分别为1.37%和1.31%，比PID减小了41%和44%，比ADRC减小了25%和27%。NRBO-ADRC策略显著提高了动态响应、超调抑制和鲁棒性，为大功率SOFC系统的多变量控制提供了有效的参考，有助于推进分布式发电。

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引用次数: 0

Influence of parameters and optimization on flow heat transfer and particle deposition in twisted elliptical tubes 参数及优化对扭椭圆管内流动换热及颗粒沉积的影响

IF 6.4 2区工程技术 Q1 THERMODYNAMICS

Case Studies in Thermal Engineering

Pub Date : 2026-01-09 DOI: 10.1016/j.csite.2026.107686

Wei Lin , Haodong Yu , Xin Wen , Junwen Cheng , Shengjie Yang , Cheng Gong , Qunyu Tang , Tangzhengzheng Tang , Jin Cao , Hong Tang , Wei Wang , Jiuyang Yu

Twisted elliptical tubes (TETs) are promising for heat exchanger applications due to their enhanced heat transfer capability, but the deposition characteristics of particles within their structure remain unclear. This study numerically investigated the effects of flattening ratio (1.2–3.0), pitch (200–800 mm), and flow velocity (0.5–1.3 m/s) on flow, heat transfer, and particle deposition patterns using the discrete phase model (DPM) in Fluent and a deposition criterion based on the Johnson-Kendall-Roberts (JKR) theory. The model was verified by experimental data, with a Nu deviation of less than 17 % and a friction factor deviation of less than 14 %. The results show that a higher flatness can enhance the convective mixing of hot and cold fluids, with the Nu increased by 15 %–40 %, but it also increases the flow resistance; a smaller pitch can enhance secondary flow, reducing the deposition amount by up to 30 %. The deposition rate showed a non-monotonic dependence on flattening ratio, with FR = 2.0 yielding the lowest fouling tendency. A multi-objective optimization using an improved particle swarm algorithm identified the optimal parameters (FR = 2.25, P = 250 mm,v = 1.28 m/s), achieving balanced performance with Nu = 185.3, f = 0.064, and Dep = 0.294. These findings provide quantitative guidance for designing efficient, anti-fouling heat exchangers in particle-laden fluid systems.

扭椭圆管（TETs）由于其增强的传热能力而在换热器中应用前景广阔，但其结构内颗粒的沉积特性尚不清楚。本研究利用Fluent中的离散相模型（DPM）和基于Johnson-Kendall-Roberts （JKR）理论的沉积准则，数值研究了扁化比（1.2-3.0）、节距（200-800 mm）和流速（0.5-1.3 m/s）对流动、传热和颗粒沉积模式的影响。实验数据验证了模型的正确性，Nu偏差小于17%，摩擦因数偏差小于14%。结果表明：较高的平整度可以增强冷热流体的对流混合，使Nu增加15% ~ 40%，但也会增加流动阻力；较小的螺距可以增强二次流，减少沉积量达30%。沉积速率与压扁率呈非单调关系，FR=2.0时结垢趋势最小。采用改进粒子群算法进行多目标优化，确定了最优参数FR=2.25， P=250 mm,v=1.28 m/s, Nu=185.3, f=0.064, Dep=0.294。这些发现为在含颗粒流体系统中设计高效、防污的热交换器提供了定量指导。

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引用次数: 0