Applied Thermal Engineering最新文献_第7页

Experimental investigation on mixing loss mechanism of different combined holes 不同组合孔混合损失机理的实验研究

IF 6.9 2区工程技术 Q2 ENERGY & FUELS

Applied Thermal Engineering

Pub Date : 2026-04-01 Epub Date: 2026-02-08 DOI: 10.1016/j.applthermaleng.2026.130158

Jialin Liu , Guoqing Li , Kaiyang Liu , Guomiao Feng , Xingen Lu

Due to the different temperature and velocity distribution in film cooling, the aerodynamic losses are unavoidable during the mixing process between the coolant and the mainstream. To address this problem, loss mechanisms were experimentally investigated by two types of double-jet holes (DJFC, DJFC7) and three types of triple-jet holes (3CY, NSIS, CRESCENT), under different blowing ratios (M = 0.5, 1.5, 2.0) and Mach numbers (Ma = 0.1, 0.2, 0.3). From the perspectives of the secondary kinetic energy coefficient and viscous entropy generation, the loss mechanism caused by coolant-mainstream mixing and viscous dissipation were systematically analyzed. The results show that in the double-jet configurations, mixing loss is reduced in DJFC7 due to its converging inlet design, which breaks up the vortex structures formed by the coolant outflow and reduces interference among multiple vortices. In the triple-jet configurations, CRESCENT exhibits the lowest total pressure loss owing to its crescent-shaped exit design, which weakens the kidney vortex effect, resulting in more stable vortex structures and minimal entropy generation. Furthermore, analysis of the Lamb vector and its divergence reveals the influence of vortex structures on coolant wall attachment behavior and momentum exchange. This study provides theoretical and experimental foundations for the design of high-performance film cooling from the viewpoint of aerodynamics.

由于气膜冷却中温度和速度分布的不同，在冷却剂与主流的混合过程中，气动损失是不可避免的。为了解决这一问题，实验研究了两种双射流孔（DJFC、DJFC7）和三射流孔（3CY、NSIS、CRESCENT）在不同吹风比（M = 0.5、1.5、2.0）和马赫数（Ma = 0.1、0.2、0.3）下的损失机理。从二次动能系数和粘性熵产生的角度，系统分析了冷却液主流混合和粘性耗散造成的损失机理。结果表明，在双射流配置下，DJFC7由于采用了会聚进口设计，打破了冷却剂流出形成的涡流结构，减少了多个涡流之间的干扰，减少了混合损失。在三喷流构型中，新月形的出口设计使新月型的总压损失最小，从而减弱了肾涡效应，使涡结构更加稳定，熵产最小。此外，对Lamb矢量及其散度的分析揭示了涡旋结构对冷却剂壁面附着行为和动量交换的影响。本研究从空气动力学的角度为高性能气膜冷却的设计提供了理论和实验依据。

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引用次数: 0

Multi-objective optimization of heat transfer and flow boiling instability in circular interrupted coaxial pin-fin microchannels 圆间断同轴针鳍微通道传热与流动沸腾不稳定性多目标优化

IF 6.9 2区工程技术 Q2 ENERGY & FUELS

Applied Thermal Engineering

Pub Date : 2026-04-01 Epub Date: 2026-02-02 DOI: 10.1016/j.applthermaleng.2026.129996

Ying Yin , Hao An , Yuan Zhang , Dexin Zhang , Liang Gong , Yan Li

While a microchannel heat sink is promising for enhancing heat transfer in high-performance chips, it still faces challenges such as flow boiling instabilities. To balance the heat transfer and instability in such systems, a multi-objective optimization framework integrating a response surface methodology (RSM) and non-dominated sorting genetic algorithm II (NSGA-II) is proposed in this paper, aiming to optimize the overall performance of flow boiling in microchannels embedded with the new designed circular interrupted coaxial pin-fins (CICP). A response surface regression model (i.e., a surrogate model) is established via a Box-Behnken design of the RSM to predict the flow boiling behavior in the CICP microchannel. NSGA-II is then applied for parametric optimization based on the surrogate model, yielding Pareto-optimal solutions. The results show that the optimal solution achieves a 39.6% reduction in flow boiling instability and a 6.3% improvement in the comprehensive performance evaluation factor compared to the original design. The improved heat transfer is primarily attributed to the distributed pin-fins, which increase the convective surface area and promote fluid mixing. Furthermore, the optimal solution was validated by a computational fluid dynamics (CFD) simulation of the flow boiling in the CICP microchannels, showing a maximum relative error of less than 4.3%. This confirms the effectiveness of the proposed optimization framework in improving the heat transfer performance while mitigating the instabilities of the flow boiling.

虽然微通道散热器有望增强高性能芯片的传热，但它仍然面临着流动沸腾不稳定性等挑战。为了平衡此类系统的传热和不稳定性，本文提出了一个集成响应面法（RSM）和非支配排序遗传算法II （NSGA-II）的多目标优化框架，旨在优化嵌入新设计的圆形间断同轴针鳍（CICP）的微通道内流动沸腾的整体性能。通过RSM的Box-Behnken设计，建立了响应面回归模型（即代理模型）来预测CICP微通道内的流动沸腾行为。然后应用NSGA-II进行基于代理模型的参数优化，得到pareto最优解。结果表明，优化后的方案与原设计相比，流动沸腾不稳定性降低39.6%，综合性能评价因子提高6.3%。改善换热的主要原因是分布的翅片增加了对流表面积，促进了流体的混合。通过计算流体力学（CFD）模拟CICP微通道内的流动沸腾，验证了最优解的有效性，最大相对误差小于4.3%。这证实了所提出的优化框架在改善传热性能的同时减轻流动沸腾的不稳定性方面的有效性。

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引用次数: 0

An open-source moving-boundary approach for shell-and-tube heat exchanger sizing optimization 壳管式换热器尺寸优化的开源移动边界法

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.2026.130193

Basile Chaudoir, Samuel Gendebien, Vincent Lemort

Conventional single-zone heat exchanger models fail to resolve local temperature gradients, property variations, and phase transitions, while high-fidelity distributed models are often too computationally demanding to be embedded in integrated design optimization. To bridge this gap, this work presents a shell-and-tube heat exchanger sizing framework that couples a novel tube-pass-aware one-dimensional moving-boundary model with a particle swarm optimization algorithm. The modeling framework includes a user-defined discretization level, allowing a tunable balance between accuracy and computational cost. The optimization objective is the minimization of total heat exchanger mass, thereby reducing thermal inertia while lowering material use, handling requirements, and overall cost. Comparative validation against published reference cases under single-phase and two-phase operating conditions demonstrates heat exchanger mass reductions of 22 to 24%, while increasing modeling fidelity. The predictive accuracy was comparatively validated with the reference studies, with heat transfer deviations of approximately 1% and pressure-drop deviations below 10% for low discretization modeling. Achieving these improvements within a reasonable computational time, the optimization results show that the factors most strongly affecting heat exchanger mass are, in order of importance, the tube-thickness assumptions (−28 to −46%) as tubes represent 60 to 80% of the total mass, the discretization level (−10 to ＋56%), and the choice of objective function (−10%).

传统的单区域热交换器模型无法解决局部温度梯度、性能变化和相变问题，而高保真的分布式模型通常对计算量要求太高，无法嵌入到集成设计优化中。为了弥补这一差距，本研究提出了一种管壳式换热器尺寸框架，该框架将一种新颖的管通道感知一维移动边界模型与粒子群优化算法相结合。建模框架包括用户定义的离散化级别，允许在精度和计算成本之间进行可调的平衡。优化目标是使换热器总质量最小化，从而减少热惯性，同时降低材料使用、处理要求和总体成本。与已发表的参考案例在单相和两相工况下的对比验证表明，在提高建模保真度的同时，换热器的质量降低了22%至24%。与参考研究对比验证了预测精度，低离散化建模的传热偏差约为1%，压降偏差低于10%。在合理的计算时间内实现这些改进，优化结果表明，影响换热器质量最强烈的因素依次为管厚假设（- 28至- 46%），因为管占总质量的60至80%，离散化水平（- 10至+56%）和目标函数的选择（- 10%）。

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引用次数: 0

Geometric optimization of solar stills: How fin height dictates heat transfer and fluid dynamics in pyramid designs 太阳能蒸馏器的几何优化：翅片高度如何决定金字塔设计中的传热和流体动力学

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.2026.130107

Sirine Dhaoui , Abdallah Bouabidi , Mohammed El Hadi Attia , Moataz M. Abdel-Aziz , Saif Ali Kadhim

This study experimentally and numerically investigates the thermal performance and freshwater productivity of a conventional pyramid solar still (CPSS) versus five modified designs (MPSS) with varying cylindrical fin heights (25, 35, 45, 55, and 65 mm). Through comprehensive testing under real solar conditions in Gabes, Tunisia, the 45 mm fin configuration demonstrated optimal performance, achieving an 18.46% higher absorber temperature (77 °C vs. CPSS's 65 °C) and 46.2% greater evaporative heat transfer coefficient (42.50 vs. 29.07 W/m²·K). Among the five MPSS variants, the 45 mm fins provided the ideal balance between heat transfer enhancement and fluid dynamics, yielding 80.9% more daily distillate (3443.07 vs. 1903.29 mL/m²) while maintaining efficient vapor circulation. Computational fluid dynamics (CFD) simulations of all five MPSS configurations revealed that while shorter fins (25–35 mm) provided limited improvement, taller fins (55–65 mm) caused flow disruptions despite their larger surface area. The 45 mm MPSS doubled energy efficiency (34.8% vs. 16.98%) and tripled exergy efficiency (3.04% vs. 1.21%) compared to CPSS, with CFD validation showing excellent agreement (R² > 0.95) for all five models. These findings demonstrate that cylindrical fin height critically impacts solar still performance, with the 45 mm MPSS emerging as the most effective design.

本研究通过实验和数值研究了传统金字塔太阳能蒸馏器（CPSS）与五种不同圆柱翅片高度（25、35、45、55和65 mm）的改进设计（MPSS）的热性能和淡水生产力。通过在突尼斯Gabes的真实太阳能条件下的综合测试，45毫米翅片结构表现出最佳性能，吸收温度提高18.46%(77°C)，蒸发换热系数提高46.2% （42.50 vs 29.07 W/m2·K）。在五种MPSS变体中，45毫米的鳍片在传热增强和流体动力学之间提供了理想的平衡，在保持有效蒸汽循环的同时，每日馏分增加80.9% （3443.07 mL/m2 vs. 1903.29 mL/m2）。计算流体动力学（CFD）模拟表明，虽然短鳍（25-35 mm）的改善效果有限，但长鳍（55-65 mm）的表面积更大，但会导致流动中断。与CPSS相比，45 mm MPSS的能源效率翻了一番（34.8%对16.98%），火用效率翻了三倍（3.04%对1.21%），CFD验证显示所有五种模型的一致性都很好（R2 > 0.95）。这些发现表明，圆柱形翅片高度对太阳能静止器的性能有重要影响，其中45毫米的MPSS是最有效的设计。

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引用次数: 0

Investigation of borehole thermal storage efficiency in rock masses and primary controlling factors 岩体井眼储热效率及主要控制因素研究

IF 6.9 2区工程技术 Q2 ENERGY & FUELS

Applied Thermal Engineering

Pub Date : 2026-04-01 Epub Date: 2026-02-23 DOI: 10.1016/j.applthermaleng.2026.130407

J. Sun , P. Pei , C. Wang , L. Tang

The thermal storage efficiency and primary controlling factors of seasonal borehole thermal energy storage (BTES) in rock masses were investigated through field investigation and numerical simulation. Gently dipping and steeply dipping fracture patterns were assumed, and the storage efficiency was calculated considering groundwater fluctuation patterns over an annual scale. The results indicated that, in the case of gently dipping fractures with stable groundwater recharge, the thermal storage efficiency reached 78.18%. Heat loss primarily occurred during the middle to late stages of the charging period and the early stage of the discharging period. In the case of steeply dipping with stable groundwater recharge, the thermal storage efficiency reached 79.35%, with heat loss predominantly occurring during the discharging period. In the case of gently dipping fractures with fluctuating groundwater recharge, the thermal storage efficiency dropped to 41.11%. Heat loss primarily occurred during the charging period, while groundwater flow served as a thermal source during the discharging period, rather than driving energy loss. Further analysis revealed that, compared to fracture dip angles, the seasonal fluctuation of groundwater had the most prominent impact on BTES performance. The findings provide scientific guidance for feasibility assessment, site selection and operation optimization of BTES projects in bedrock.

通过现场调查和数值模拟，研究了岩体季节性钻孔储热的储热效率和主要控制因素。假设缓倾斜和急倾斜裂缝模式，考虑地下水年尺度波动规律，计算储层效率。结果表明：在缓倾斜裂缝、地下水补给稳定的情况下，储热效率可达78.18%；热损失主要发生在充电期中后期和放电期前期。在地下水补给稳定的陡倾斜情况下，蓄热效率达到79.35%，热损失主要发生在排水期。在缓倾斜裂缝、地下水回灌波动情况下，储热效率降至41.11%。热损失主要发生在充注期，而地下水在泄放期作为热源，而不是驱动能量损失。进一步分析发现，与裂缝倾角相比，地下水季节波动对BTES性能的影响最为显著。研究结果为基岩BTES项目的可行性评价、选址和运行优化提供了科学指导。

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引用次数: 0

Copper-based photothermal superhydrophobic surfaces with multi-level structures for applications of anti-icing, ice-melting and rapid deicing 具有多层结构的铜基光热超疏水表面用于防冰、融冰和快速除冰

IF 6.9 2区工程技术 Q2 ENERGY & FUELS

Applied Thermal Engineering

Pub Date : 2026-04-01 Epub Date: 2026-02-18 DOI: 10.1016/j.applthermaleng.2026.130286

Liwei Dong , Minxia Li , Chaobin Dang , Jintao Niu , Chenxu Wang

The photothermal superhydrophobic surface, which combines photothermal and superhydrophobic properties, representing a key technology for achieving surface anti-icing, ice-melting and rapid deicing. Three copper-based photothermal surfaces were prepared: a superhydrophobic copper surface (SHCS), a Cu-Ag superhydrophobic photothermal surface (SHCS (Cu-Ag)) and a Cu-CuO superhydrophobic photothermal surface (SHCS (Cu-CuO)). The smooth bare copper surface (SBCS) was used as the control surface. The SHCS (Cu-Ag) and the SHCS (Cu-CuO) are based on the micro-nano structure of the SHCS by introducing photothermal materials silver nanoparticles and copper oxide, with absorptivity as high as 95.50% and 95.90% at 808 nm, respectively. The results of the anti-icing tests indicate that the SHCS (Cu-CuO) delayed icing by 1625 s at −10 °C compared to the SBCS due to the significant increase in its surface roughness. Horizontal photothermal ice-melting experiments were conducted on each surface, and the ice-melting initiation illumination intensities of each surface were obtained. Meanwhile, the influence of the variation of illumination intensity on the ice-melting process was discussed. The initiation illumination intensity of the SHCS at the initial surface stabilization temperature of −10 °C is 0.15 W/cm², which is 0.85 W/cm² lower than that of the SBCS. The initiation radiation intensities of SHCS (Cu-Ag) and SHCS (Cu-CuO) were further reduced to 0.10 W/cm² due to the further improvement of their photothermal capabilities. The advantages of the SHCS (Cu-Ag) and the SHCS (Cu-CuO) are primarily evident in the low illumination intensity range. Compared with the SHCS, at an illumination of 0.15 W/cm², the total-ice-melting times of the SHCS (Cu-Ag) and the SHCS (Cu-CuO) are decreased by 33.40% and 51.53%, respectively. Furthermore, photothermal deicing experiments on inclined surfaces demonstrate that the SHCS (Cu-CuO) exhibits the most outstanding deicing performance. Even at the initiation illumination intensity, rapid ice removal is achieved at illumination angles of 60° at both −10 °C and −15 °C. And compared with the illumination energy of the SHCS, the energy consumption of the SHCS (Cu-CuO) is reduced by about 14.31% at −10 °C.

光热超疏水表面结合了光热和超疏水的特性，是实现表面防冰、融冰和快速除冰的关键技术。制备了三种铜基光热表面：超疏水铜表面（SHCS）、Cu-Ag超疏水光热表面（SHCS (Cu-Ag)）和Cu-CuO超疏水光热表面（SHCS (Cu-CuO)）。以光滑裸铜表面（SBCS）作为对照面。SHCS （Cu-Ag）和SHCS （Cu-CuO）是基于SHCS的微纳结构，通过引入光热材料银纳米粒子和氧化铜，在808 nm处的吸收率分别高达95.50%和95.90%。抗冰试验结果表明，在−10℃下，由于表面粗糙度的显著提高，与SBCS相比，SHCS （Cu-CuO）延迟了1625 s的结冰时间。在各表面进行水平光热融冰实验，得到各表面的融冰起始光照强度。同时，讨论了光照强度变化对融冰过程的影响。在- 10℃的初始表面稳定温度下，SHCS的起始光照强度为0.15 W/cm2，比SBCS的起始光照强度低0.85 W/cm2。由于光热性能的进一步提高，SHCS （Cu-Ag）和SHCS （Cu-CuO）的起始辐射强度进一步降低到0.10 W/cm2。SHCS （Cu-Ag）和SHCS （Cu-CuO）的优势主要表现在低照度范围内。与SHCS相比，在0.15 W/cm2光照下，SHCS （Cu-Ag）和SHCS （Cu-CuO）的总融冰次数分别减少了33.40%和51.53%。此外，在倾斜表面上进行的光热除冰实验表明，SHCS （Cu-CuO）的除冰性能最为优异。即使在初始照明强度下，在−10°C和−15°C的照明角度为60°时，也可以实现快速除冰。与SHCS的照明能量相比，在−10°C时，SHCS的能耗（Cu-CuO）降低了约14.31%。

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引用次数: 0

Optimisation study of solar-coupled combined heat and power for crude oil export terminals 原油出口终端太阳能耦合热电联产优化研究

IF 6.9 2区工程技术 Q2 ENERGY & FUELS

Applied Thermal Engineering

Pub Date : 2026-04-01 Epub Date: 2026-01-22 DOI: 10.1016/j.applthermaleng.2026.129787

Liang Tian, Fuxing Zhao, Jiachao Wu

Addressing the issues of high energy consumption, high carbon emissions, and significant load fluctuations at oilfield crude export terminals, this paper investigates a solar cogeneration system. Its core lies in employing coupled molten salt thermal storage technology to resolve the contradictions between energy intermittency and seasonality. Using Aspen Plus software, a collection-storage-Rankine cycle model was constructed for different working fluids. Embedding thermodynamic constraints via a physical information neural network, the study developed an ANN-NSGA-II multi-objective collaborative optimization framework. This achieved Pareto optimisation of the system's thermodynamic energy efficiency, economic benefits, and environmental performance. The multi-objective optimisation comparison results indicate that the optimal

{RD}_{2}

system (a combined heat and power configuration utilizing molten salt for direct collection and storage, with a steam Rankine cycle for power generation) based on a steam Rankine cycle achieves a maximum thermal efficiency of 55.43%, with an internal rate of return (IRR) of 11.23% and annual CO₂ emissions reductions of 931.36 tonnes. Sensitivity analysis indicates that a power/heat coupling diverter ratio exceeding 0.4 ensures positive net electricity generation and sustained carbon reduction growth. Increasing the diversion ratio diminishes IRR, permitting dynamic operational optimisation based on real-time meteorological conditions and grid peak-shaving demands. The molten salt thermal storage system enables effective intraday energy management. It facilitates intelligent operational scheduling based on electricity price signals: generating power at full capacity during periods of high solar irradiance and high electricity prices, while storing heat during low-price periods. This strategy, optimized via the NSGA-II algorithm within a multi-dimensional framework considering solar radiation, electricity pricing, and load patterns, significantly reduces daily reliance on external heat supplementation and grid electricity purchases, demonstrating the engineering feasibility of the proposed system for managing daily energy imbalances.

This work establishes a replicable, optimized technical paradigm for solar-assisted decarbonization of industrial energy systems, offering a viable pathway for the large-scale substitution of fossil fuels in the oil and gas sector.

针对油田原油出口终端高能耗、高碳排放、负荷波动大的问题，对太阳能热电联产系统进行了研究。其核心在于采用耦合熔盐蓄热技术，解决能源间歇性与季节性的矛盾。利用Aspen Plus软件，建立了不同工质的收集-储存-朗肯循环模型。通过物理信息神经网络嵌入热力学约束，开发了ANN-NSGA-II多目标协同优化框架。这实现了系统热力学能源效率、经济效益和环境性能的帕累托优化。多目标优化对比结果表明，以蒸汽朗肯循环为基础的RD2系统（采用熔盐直接收集和储存，采用蒸汽朗肯循环发电的热电联产结构）的最优热效率为55.43%，内部收益率（IRR）为11.23%，年二氧化碳排放量减少931.36吨。敏感性分析表明，功率/热耦合分流比超过0.4，可确保净发电量为正，碳减排持续增长。增加导流比可以降低IRR，允许基于实时气象条件和电网调峰需求的动态操作优化。熔盐蓄热系统可实现有效的日间能源管理。实现基于电价信号的智能调度，在太阳辐照度高、电价高时满负荷发电，在电价低时蓄热。该策略通过NSGA-II算法在考虑太阳辐射、电价和负荷模式的多维框架内进行优化，显著降低了日常对外部供热和电网购电的依赖，证明了所提出的系统在管理日常能源失衡方面的工程可行性。这项工作为太阳能辅助工业能源系统脱碳建立了一个可复制的、优化的技术范例，为石油和天然气部门大规模替代化石燃料提供了一条可行的途径。

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引用次数: 0

Combustion enhancement characteristics of backward-facing step in an axisymmetric scramjet 轴对称超燃冲压发动机后台阶的燃烧增强特性

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.2026.130188

Liu Yang , Yixin Yang , Tongwang Shi , Tao Tang , Mingbo Sun , Wang Han , Qinyuan Li , Rui Gu , Hongbo Wang , Dapeng Xiong , Jiajian Zhu

The supersonic combustion enhancement characteristics of a combined combustor configuration consisting of a backward-facing step and a cavity are investigated numerically in this paper. Numerical simulations are conducted using a hybrid RANS/LES method. Numerical validation is performed on an axisymmetric cavity supersonic combustor as the baseline configuration. The numerical results agree well with the experimental measurements. On this basis, this paper proposes a combined configuration of a backward-facing step and a cavity, introducing a connecting step upstream of the cavity to achieve combustion enhancement. By comparing the two configurations, it is found that the addition of the backward-facing step regulates the heat release distribution, shortens the premixing process, and lifts the boundary layer at the intersection zone of strong shock waves. In the combined configuration, the inflow decelerates under strong compression waves, resulting in extended fuel residence time, elevated vortex stretching, raised jet penetration boundary, all of which promote fuel mixing. Combustion initiates earlier in the combined configuration, with the step and its upstream region serving as key hot product zones. Premixed combustion dominates the flame combustion mode, and subsonic combustion prevails upstream of the step. The combustion efficiency is improved. Meanwhile, this improvement is accompanied by an increase in total pressure loss. In the combined configuration, the transport and fuel entrainment capabilities of large-scale vortex structures in the upstream region of the cavity are enhanced, leading to faster reaction rates in local areas. Most of the combustion occurs in the wrinkled flamelet mode and corrugated flamelet mode, with a small portion in the thin reaction zone mode.

本文对后台阶与空腔组合燃烧室结构的超声速燃烧增强特性进行了数值研究。采用RANS/LES混合方法进行了数值模拟。以轴对称腔型超声速燃烧室为基准进行了数值验证。数值计算结果与实验测量结果吻合较好。在此基础上，本文提出了后向台阶与空腔的组合构型，在空腔的上游引入连接台阶来实现燃烧增强。通过对比两种构型发现，后向台阶的加入调节了热释放分布，缩短了预混过程，提升了强激波交汇区边界层。在组合构型下，在强压缩波作用下，进流减速，导致燃油停留时间延长，涡流拉伸升高，射流穿透边界升高，这些都促进了燃油混合。在组合配置中，燃烧开始得更早，台阶及其上游区域是关键的热产物区。火焰燃烧方式以预混燃烧为主，阶梯上游以亚音速燃烧为主。提高了燃烧效率。同时，这种改善伴随着总压损失的增加。在组合构型下，腔体上游区域大尺度涡结构的输运和燃料夹带能力得到增强，导致局部区域的反应速度更快。燃烧主要发生在起皱火焰模式和波纹火焰模式下，小部分发生在薄反应区模式下。

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引用次数: 0

Investigation of self-pressurization in liquid hydrogen storage tanks using a novel coupled multi-node non-equilibrium thermodynamic and two-dimensional thermal resistance network model 利用一种新的多节点非平衡热力学和二维热阻网络耦合模型研究液氢储罐的自加压

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.2026.130166

Qingwei Zhai , Peng Wang , Zhonghui Tian , Kun Wang , Dongxu Han , Yujie Chen , Dongliang Sun , Bo Yu , Weitao Zhang

Thermal management of liquid hydrogen (LH₂) storage tanks is essential to ensure the safety and energy efficiency of storage and transportation systems, where accurate prediction of the complex internal thermal processes requires high-performance simulation models. Conventional computational fluid dynamics (CFD) models can capture detailed features of gas-liquid phase change and temperature distribution but are computationally intensive. Standard thermodynamic methods are efficient but cannot represent temperature gradients or the dynamic coupling of multilayer insulation structures. In this study, a coupled simulation approach is taken that integrates a multi-node non-equilibrium thermodynamic model with a two-dimensional thermal resistance network, which is capable of capturing gas–liquid phase change dynamics, temperature gradients, and the heat flux distribution in insulation structures. Applying this model, the effects of tank geometry, initial conditions, and insulation performance on the self-pressurization rate and boil-off losses have been systematically investigated. Sensitivity analysis was employed to quantify individual and synergistic effects. The results have shown that increasing the tank radius delays pressure rise but significantly increases boil-off, whereas increasing the height has limited effects. Moreover, lowering the vapor temperature slightly mitigates pressurization with a minimal effect on boil-off. Moderate pressurization near saturation effectively reduces boil-off. Lowering the boundary temperature and maintaining a high vacuum serve to suppress pressurization and vaporization. In addition, increasing the liquid level reduces boil-off but accelerates vapor heating with a slight increase in pressure. Based on the sensitivity results, optimization strategies that prioritize radius, boundary temperature, pressure, and liquid level, in tandem with liquid temperature and vacuum adjustments, are proposed to provide practical guidance for LH₂ tank design and operation.

液态氢（LH2）储罐的热管理对于确保储运系统的安全和能源效率至关重要，其中复杂的内部热过程的准确预测需要高性能的仿真模型。传统的计算流体动力学（CFD）模型可以捕捉气液相变和温度分布的详细特征，但计算量大。标准热力学方法是有效的，但不能表示温度梯度或多层保温结构的动态耦合。本研究采用多节点非平衡热力学模型与二维热阻网络相结合的耦合模拟方法，能够捕捉保温结构内的气液相变动力学、温度梯度和热流密度分布。应用该模型，系统地研究了储罐几何形状、初始条件和保温性能对自增压速率和蒸发损失的影响。敏感性分析用于量化个体效应和协同效应。结果表明，增大储罐半径可延缓压力上升，但显著提高蒸发率，而增大储罐高度影响有限。此外，降低蒸汽温度稍微减轻了压力，对蒸发的影响最小。接近饱和的适度加压有效地减少了沸腾。降低边界温度和保持高真空有助于抑制加压和汽化。此外，增加液面会减少蒸发，但会随着压力的轻微增加而加速蒸汽加热。根据灵敏度结果，提出了半径、边界温度、压力、液位优先，液温、真空调节优先的优化策略，为LH₂罐的设计和运行提供实用指导。

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引用次数: 0

Mode-dependent reconfiguration of exergy destruction and optimization of an air-source heat pump with a liquid-storage gas-liquid separator 带储液气液分离器的空气源热泵用能破坏模式重构与优化

IF 6.9 2区工程技术 Q2 ENERGY & FUELS

Applied Thermal Engineering

Pub Date : 2026-04-01 Epub Date: 2026-02-27 DOI: 10.1016/j.applthermaleng.2026.130458

Longxia Ma , Fenghao Wang , Ming Wang , Jinghua Jiang , Qing Xia , Yongjun Sun , Sheng Zhang , Zhihua Wang , Mengjie Song

Frost formation significantly degrades the performance of air-source heat pumps (ASHPs) in cold climates. A previous study on a novel ASHP incorporating a liquid-storage gas-liquid separator (Ls-Gls) demonstrated effective frost suppression based on first-law analysis. However, second-law aspects-particularly the reorganization of irreversibility across operational modes-remain insufficiently understood. To address this gap, this study proposes a coupled exergy-pinch analysis framework for both heating and defrosting modes. The results reveal a clear mode-dependent reconfiguration of dominant exergy destruction sources: despite increased compressor work, total system exergy destruction during defrosting is 7.9% lower than during heating,mainly due to a reduced pressure ratio that suppresses compressor-related irreversibility while heat-transfer losses intensify in the outdoor heat exchanger under the fixed 0 °C frost-layer constraint. Pinch analysis further quantifies the spatial shift of dominant irreversibility from the evaporator outlet during heating to the frost-layer interface during defrosting. Compressor isentropic efficiency is identified as the most influential parameter governing overall exergy performance. More importantly, a mode-specific optimization principle is established: an optimal internal heat-transfer temperature difference of 5 K is identified for the Ls-Gls in heating mode, while defrosting performance is primarily governed by the energy grade of the stored refrigerant. Collectively, these findings establish mode-specific principles to guide strategic optimization. This study shifts the optimization paradigm from component-based to mode-aware system design, providing a foundational guideline for next-generation adaptive ASHPs.

在寒冷气候下，霜的形成显著降低了空气源热泵（ASHPs）的性能。先前的一项研究表明，基于第一定律分析，采用储液气液分离器（Ls-Gls）的新型空气源热泵能够有效抑制霜冻。然而，第二定律方面——特别是跨操作模式的不可逆性重组——仍然没有得到充分的理解。为了解决这一差距，本研究提出了加热和除霜模式的耦合火用夹紧分析框架。结果显示，主要的火用破坏源存在明显的模式依赖重构：尽管压缩机做功增加，但除霜过程中的系统总火用破坏比加热过程低7.9%，这主要是由于在固定的0°C霜层约束下，压力比降低抑制了压缩机相关的不可逆性，同时强化了室外换热器中的传热损失。夹点分析进一步量化了加热过程中从蒸发器出口到除霜过程中霜层界面的主导不可逆性的空间转移。压气机等熵效率是影响压气机整体火用性能的最重要参数。更重要的是，建立了特定于模式的优化原则：在加热模式下，Ls-Gls的最佳内部传热温差为5 K，而除霜性能主要由储存制冷剂的能量等级决定。总的来说，这些发现建立了特定于模式的原则来指导战略优化。该研究将优化范例从基于组件的系统设计转变为模式感知系统设计，为下一代自适应空气源热泵提供了基础指导。

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