IF 2.1 3区工程技术 Q3 PHYSICS, APPLIED

Cryogenics

Pub Date : 2025-12-09 DOI: 10.1016/j.cryogenics.2025.104258

Błażej Skoczeń , Elwira Schmidt , Rafał Schmidt , Angelika Kaciuba

Accurate prediction of the behaviour of irradiated stainless-steel components operating at cryogenic temperatures is of fundamental importance for the scientific community engaged in the design and construction of superconducting particle accelerators. The high-field magnet structures employed in these systems are manufactured from metastable austenitic stainless steels, which are susceptible to strain-induced fcc-bcc martensitic transformation under extreme thermal and mechanical conditions. In addition, exposure to high-energy particle beams and the associated generation of secondary particle fluxes give rise to nano- and micro-scale radiation damage, originating from interactions between incident particles and the crystal lattice. A central challenge in understanding the mechanical response of these materials lies in quantifying radiation-induced hardening, which is governed by microstructural mechanisms such as the interaction of dislocations with irradiation-generated defects and secondary-phase precipitates. To investigate the effect of irradiation on the hardening behaviour of two-phase alloys, a closed-form analytical solution for the uniaxial stress state is particularly advantageous. Accordingly, a multiaxial constitutive model capturing plastic-strain-driven fcc-bcc phase transformation, together with a physically based model describing the evolution of radiation-induced defect populations, has been developed. On this basis, an original hardening model, formulated within a mean-field framework and grounded in the Orowan mechanism, has been proposed. Model predictions were evaluated against experimental data obtained both in-house and from the literature to ensure accurate calibration. The progression of microstructural changes accompanying the strain-induced transformation, as well as the accumulation of radiation damage, was examined in detail.

准确预测低温下辐照不锈钢元件的行为对从事超导粒子加速器设计和建造的科学界具有重要意义。这些系统中使用的高磁场结构由亚稳奥氏体不锈钢制成，在极端的热和机械条件下，易发生应变诱导的fcc-bcc马氏体转变。此外，暴露于高能粒子束和相关的次级粒子通量的产生会引起纳米和微观尺度的辐射损伤，这是由入射粒子与晶格之间的相互作用引起的。理解这些材料的力学响应的核心挑战在于量化辐射诱发硬化，这是由微观结构机制控制的，如位错与辐射产生的缺陷和二次相沉淀的相互作用。为了研究辐照对两相合金硬化行为的影响，单轴应力状态的封闭解析解是特别有利的。因此，一个多轴本构模型捕获塑性应变驱动的fcc-bcc相变，以及一个基于物理的模型描述辐射诱导缺陷种群的演变，已经被开发出来。在此基础上，提出了一个原始的硬化模型，该模型是在平均场框架内制定的，并以Orowan机制为基础。根据内部和文献中获得的实验数据对模型预测进行评估，以确保准确校准。详细研究了随应变诱导转变而发生的显微组织变化的过程以及辐射损伤的累积。

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引用次数: 0

Cryogenic ultrasonic fatigue: mechanisms, advancements, and insights 低温超声疲劳：机制，进展和见解

IF 2.1 3区工程技术 Q3 PHYSICS, APPLIED

Cryogenics

Pub Date : 2025-12-06 DOI: 10.1016/j.cryogenics.2025.104257

MohammadBagher Mahtabi , Mojtaba Roshan , Md Muhiul Islam Muhit , Alireza Behvar , Meysam Haghshenas

As a high-throughput fatigue data generation testing technique, ultrasonic fatigue (USF) testing at 20 kHz enables rapid evaluation of fatigue behavior, particularly in the high cycle fatigue (HCF) and very high cycle fatigue (VHCF) regimes. As temperature strongly influences deformation and fracture mechanisms, and given that many components in service experience cyclic loading under both ambient and non-ambient conditions, studying environment-dependent USF in the high-temperature isothermal and subzero cryogenic regimes has become essential for assessing damage mechanisms under extreme operating environments. At cryogenic temperatures, in particular, many materials exhibit increased stiffness and reduced fracture toughness, which often shift fatigue crack initiation from interior defects, typical of room-temperature HCF and VHCF, to surface or near-surface regions dominated by brittle cleavage or limited plasticity. This review establishes recent progress in cryogenic USF, emphasizing advances in testing methods, thermal management, and mechanistic understanding of crack initiation. It demonstrates that low-temperature USF not only accelerates fatigue assessment but also exposes how reduced temperature alters deformation and crack-initiation pathways, offering new insights for materials design and qualification in aerospace, cryogenic, and high-frequency engineering applications.

作为一种高通量疲劳数据生成测试技术，20 kHz的超声疲劳（USF）测试可以快速评估疲劳行为，特别是在高周疲劳（HCF）和甚高周疲劳（VHCF）状态下。由于温度强烈影响变形和断裂机制，并且考虑到许多部件在环境和非环境条件下都会经历循环加载，因此研究高温等温和零下低温条件下的环境相关USF对于评估极端操作环境下的损伤机制至关重要。特别是在低温下，许多材料表现出刚度增加和断裂韧性降低，这通常将疲劳裂纹的萌生从内部缺陷（典型的室温HCF和VHCF）转移到由脆性解理或有限塑性主导的表面或近表面区域。本文综述了低温USF的最新进展，重点介绍了测试方法、热管理和裂纹起裂机理的研究进展。该研究表明，低温USF不仅加速了疲劳评估，而且揭示了降低温度如何改变变形和裂纹起裂途径，为航空航天、低温和高频工程应用中的材料设计和鉴定提供了新的见解。

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引用次数: 0

Study on bending and torsion properties of REBCO Brickwall-type multi-filamentary tapes REBCO砖墙型多丝带的弯曲和扭转性能研究

IF 2.1 3区工程技术 Q3 PHYSICS, APPLIED

Cryogenics

Pub Date : 2025-12-04 DOI: 10.1016/j.cryogenics.2025.104261

Jinhao Shi , Jiulong Zhang , Jingfeng Zhang , Chao Zhou , Jiaxin Li , Shaoqing Wei , Zuoguang Li , Zhan Zhang

To investigate the bending and torsion properties of REBCO Brickwall-type multi-filamentary tapes, this study employed roll-to-roll ultraviolet picosecond laser cutting technology to fabricate Brickwall-type 3-filament, 6-filament, and 10-filament tapes using a 1.00 mm cutting slot length and spacing. The current-carrying performance of these tapes under bending and torsion conditions was tested and analyzed, respectively. Experimental results indicate that, under 77 K and self-field conditions, the Brickwall-type multi-filamentary tapes exhibit excellent stability in current-carrying performance, with the critical current degradation rate controlled within 5.00 %, thereby retaining the original current-carrying capacity of the tapes. Results of the bending tests showed that the compressive bending strain tolerance of the samples reaches 1.17 % (with a bending radius of 3.00 mm); meanwhile, their tensile bending strain tolerance decreases significantly as the number of filaments increases. Specifically, both the non-striated tape and the 3-filament tape had a tensile bending strain tolerance of 0.397 % (with a bending radius of 6.00 mm); when the number of filaments in the tapes increased to 6 and 10, their tensile bending strain tolerance decreased to 0.341 % (with a bending radius of 7.00 mm). Results of the torsion tests demonstrated that the non-striated tape, 3-filament tape, and 6-filament tape followed a consistent degradation pattern, while the 10-filament tape showed a distinct difference. When the shear strain reached 0.304 % (corresponding to a torsion angle of 300°), the critical currents of the non-striated tape, 3-filament tape, 6-filament tape, and 10-filament tape degraded by approximately ∼ 0.859 %, ∼2.51 %, ∼ 4.80 %, and ∼ 13.8 %, respectively.

为了研究REBCO brickwall型多丝胶带的弯曲和扭转性能，本研究采用卷对卷紫外皮秒激光切割技术，以1.00 mm的切割槽长度和间距制备了brickwall型3丝、6丝和10丝胶带。分别测试和分析了弯曲和扭转条件下的载流性能。实验结果表明，在77 K和自场条件下，brickwall型多丝带的载流性能表现出优异的稳定性，临界电流降解率控制在5.00 %以内，保持了带的原始载流能力。弯曲试验结果表明，试样的压缩弯曲应变容限达到1.17%（弯曲半径为3.00 mm）；同时，随着长丝数量的增加，其拉伸弯曲应变容差显著降低。其中，无条纹带和3丝带的拉伸弯曲应变容差均为0.397 %（弯曲半径为6.00 mm）；当带中长丝数增加到6根和10根时，其拉伸弯曲应变容差减小到0.341%（弯曲半径为7.00 mm）。扭转试验结果表明，无条纹带、3丝带和6丝带具有一致的退化模式，而10丝带表现出明显的差异。当剪切应变达到0.304 %（对应于300°的扭转角）时，无条纹带、3丝带、6丝带和10丝带的临界电流分别下降了约0.859%、2.51%、4.80%和13.8%。

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引用次数: 0

Asynchronous quenching in cryogenic thermoacoustic systems under active control 主动控制下低温热声系统的异步猝灭

IF 2.1 3区工程技术 Q3 PHYSICS, APPLIED

Cryogenics

Pub Date : 2025-12-04 DOI: 10.1016/j.cryogenics.2025.104260

Yafeng Niu , Lulu Hu , Yingwen Liu , Bo Gao

Active control is a flexible and cost-effective method for mitigating the thermoacoustic instability, a common issue in cryogenic systems. Under active control, the oscillation amplitude may be effectively attenuated when the self-excited oscillatory system undergoes asynchronous quenching. In this paper, the forcing parameters were adjusted to achieve asynchronous quenching in a cryogenic helium tube system under open-loop control. When the forcing frequency deviates significantly from the self-excited frequency, it was found that as the forcing intensity increases, the system undergoes the torus-birth bifurcation, transitioning from periodic to quasi-periodic, followed by the torus-death bifurcation, transitioning from quasi-periodic to periodic, eventually locking into the external forcing. The occurrence of asynchronous quenching coincides with the torus-death bifurcation. The oscillation amplitude can be reduced by 32% before locking into external forcing. Furthermore, the response characteristics of pressure and heat absorption rate to external forcing were analyzed. The results indicate that the heat absorption rate responds more quickly to the external forcing. As the forcing intensity increases, the forced system exhibits an amplitude modulation phenomenon like “beats”. Unlike the linear superposition of self-excited oscillation and external forcing, the observed amplitude variations are found to be related to the phase difference between pressure and heat absorption rate.

主动控制是一种灵活且经济的方法，可以减轻低温系统中常见的热声不稳定性问题。在主动控制下，自激振荡系统发生异步猝灭时，振荡幅度可以得到有效的衰减。在开环控制下，通过调整强制参数实现低温氦管系统的异步淬火。当强迫频率明显偏离自激频率时，发现随着强迫强度的增加，系统经历环面出生分岔，从周期向准周期过渡，然后是环面死亡分岔，从准周期向周期过渡，最终锁定外部强迫。非同步猝灭的发生与环-死亡分岔同时发生。在锁定到外部强迫之前，振荡幅度可以减少32%。此外，还分析了压力和吸热率对外力的响应特性。结果表明，热吸收率对外力的响应更快。随着强迫强度的增大，强迫系统表现出“拍”的调幅现象。与自激振荡和外强迫的线性叠加不同，观测到的振幅变化与压力和吸热速率之间的相位差有关。

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引用次数: 0

Energy, exergy, economic, and environmental assessment of a transcritical triple-cascade mixed refrigerant cycle for hydrogen liquefaction 跨临界三梯级混合制冷剂循环氢液化的能源、能源、经济和环境评价

IF 2.1 3区工程技术 Q3 PHYSICS, APPLIED

Cryogenics

Pub Date : 2025-12-04 DOI: 10.1016/j.cryogenics.2025.104254

M. Shawky Ismail , M. Abd ElSalam ElSeuofy , Abdelhamid Attia , Wael M. El-Maghlany , Mohamed ElHelw

Efficient and environmentally responsible liquefied hydrogen storage systems are pivotal for advancing the global hydrogen economy and supporting the Sustainable Development Goals (SDGs). However, the high energy demand and carbon footprint of conventional hydrogen liquefaction remain major barriers to large-scale deployment. This study presents a conceptual design for transcritical pseudo-liquid hydrogen with a density of 70.11 kg/m³, enabled by dual mixed-refrigerant (MR) cycles for pre-cooling and deep cooling, combined with a tertiary nitrogen refrigeration loop. Process simulations were conducted in Aspen HYSYS and optimized using Aspen Optimizer, with a focus on MR composition and key operating parameters. The optimized TCMR configuration achieves a 9 % decrease in specific energy consumption (SEC) to 6.25 kWh/kg H₂, compared with the baseline case. It also delivers a Figure of Merit (FOM) of 52.57 %, while lowering product pressure from 100 to 80 bar and keeping compressors safe discharge temperature at a maximum of 126 °C. The economic evaluation indicates a 7 % reduction in operating costs relative to the baseline, yielding a specific liquefaction cost of 1.13 USD/kg. The environmental assessment further shows significant improvements, with a 24.5 % reduction in Scope 1 emissions and a 7.4 % reduction in Scope 2 emissions, resulting in an overall 20 % decrease in carbon footprint compared with the DCMR case. These results confirm the technical feasibility and environmental advantages of the proposed TCMR-based system, offering a high-density, low-carbon, and energy-efficient pathway for next-generation hydrogen liquefaction and storage.

高效、环保的液化氢储存系统对于推进全球氢经济和支持可持续发展目标（sdg）至关重要。然而，传统氢液化的高能源需求和碳足迹仍然是大规模部署的主要障碍。本研究提出了密度为70.11 kg/m3的跨临界伪液态氢的概念设计，通过双混合制冷剂（MR）循环进行预冷和深度冷却，并结合三级氮制冷回路。在Aspen HYSYS中进行了过程模拟，并使用Aspen Optimizer进行了优化，重点研究了MR组成和关键操作参数。与基线情况相比，优化后的TCMR配置使比能耗（SEC）降低了9%，降至6.25 kWh/kg H2。它还提供52.57%的性能指标（FOM），同时将产品压力从100 bar降低到80 bar，并将压缩机的安全排放温度保持在最高126°C。经济评估表明，与基线相比，运营成本降低了7%，具体液化成本为1.13美元/公斤。环境评估进一步显示了显著的改善，范围1的排放量减少了24.5%，范围2的排放量减少了7.4%，与DCMR案例相比，碳足迹总体减少了20%。这些结果证实了提出的基于tcmr的系统的技术可行性和环境优势，为下一代氢液化和储存提供了高密度、低碳和节能的途径。

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引用次数: 0

Optimization and analysis of a new liquefied natural gas and nitrogen cascade pre-cooling hydrogen liquefaction process 液化天然气-氮气叶栅预冷氢液化新工艺的优化与分析

IF 2.1 3区工程技术 Q3 PHYSICS, APPLIED

Cryogenics

Pub Date : 2025-12-01 DOI: 10.1016/j.cryogenics.2025.104253

Shanshan Sun , Wenquan Jiang , Fan Yang , Changshun Wang , Junjie Liu , Meng Yang

Liquid hydrogen storage currently represents the most prominent method among hydrogen storage technologies. To minimize the energy demand of the hydrogen liquefaction system, a hydrogen liquefaction system which utilizes liquefied natural gas (LNG) and a nitrogen (N₂) reverse Brayton cycle for cascade pre-cooling of hydrogen is designed. The comparative analysis of the proposed hydrogen liquefaction improvement system with other systems shows that the proposed system has great advantages. Through systematic optimization, the system achieves a specific energy consumption (SEC) of 5.24 kWh/kg_LH2, a coefficient of performance (COP) of 0.254, and an exergy efficiency (η_ex) of 58.88%. Furthermore, by leveraging the surplus cold energy from LNG for pre-cooling the cryogenic refrigerant prior to inter-stage compression in the cryogenic cooling process, the SEC decreases by 8.87% and η_ex increases by 8.83% compared to conventional ambient temperature pre-cooling methods.

液氢储存是目前储氢技术中最突出的一种方法。为了最大限度地减少氢液化系统的能源需求，设计了一种利用液化天然气（LNG）和氮气（N2）逆布雷顿循环对氢进行串级预冷的氢液化系统。将所提出的氢液化改进系统与其他系统进行了对比分析，表明所提出的系统具有很大的优势。通过系统优化，系统比能耗（SEC）为5.24 kWh/kgLH2，性能系数（COP）为0.254，火用效率（ηex）为58.88%。此外，通过在低温冷却过程中利用LNG的剩余冷能在级间压缩之前对低温制冷剂进行预冷，与传统的环境温度预冷方法相比，SEC降低了8.87%，ηex增加了8.83%。

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引用次数: 0

AC loss analysis of magnetic gear system with superconducting component 带超导元件的磁齿轮系统交流损耗分析

IF 2.1 3区工程技术 Q3 PHYSICS, APPLIED

Cryogenics

Pub Date : 2025-11-30 DOI: 10.1016/j.cryogenics.2025.104255

Emre Akyerden, Ahmet Cansız

Magnetic gears, which utilize specially arranged permanent magnets in rotating mechanisms, offer significant advantages over conventional mechanical gears. Despite their capability for high torque transmission, their industrial adoption remains limited due to torque density and loss constraints. To address this issue, recent studies have focused on improving flux modulation between the rotors through innovative magnetic and material configurations. Superconductors, with their unique electromagnetic properties, introduce new possibilities for enhancing magnetic gear performance. In this study, a superconducting magnetic gear system was analyzed using finite element simulations in COMSOL Multiphysics. A cylindrical coaxial magnetic gear with a 20/6 pole configuration was evaluated under three stator (pole piece) material arrangements: Steel & Air, Steel & Superconductor (SC), and Superconductor & Air. Torque optimization was performed using the derivative-free BOBYQA algorithm, and AC (iron) losses were assessed based on the Bertotti loss model. The results demonstrate that optimization enhances torque transmission by factors of 3.5–5.1, while losses increase only 2.6–2.7 times. Across all configurations, the torque growth consistently outpaces the rise in losses, confirming an overall improvement in energy efficiency and torque density. Among the examined configurations, the Steel & SC combination yielded the highest absolute torque, whereas the SC & Air configuration exhibited the greatest relative improvement due to the absence of iron losses. These outcomes indicate that superconductors can substantially improve torque performance while maintaining manageable loss levels, effectively balancing the torque–loss trade-off. The study also reveals that optimization alters the effective gear ratio by modifying material volume distributions, underscoring a critical design consideration for superconducting magnetic gears. Overall, the findings provide valuable insights for multi-objective optimization strategies and offer a solid foundation for future experimental implementations.

磁齿轮，利用特别安排的永磁体在旋转机构，提供显著的优势比传统的机械齿轮。尽管它们具有高扭矩传输能力，但由于扭矩密度和损耗限制，它们的工业应用仍然有限。为了解决这个问题，最近的研究集中在通过创新的磁性和材料配置来改善转子之间的磁通调制。超导体以其独特的电磁特性，为提高磁性齿轮的性能提供了新的可能性。本文采用COMSOL Multiphysics软件对超导磁齿轮系统进行了有限元仿真分析。在三种定子（极片）材料布置下，对具有20/6极结构的圆柱同轴磁齿轮进行了评估：钢&；空气，钢&；超导（SC）和超导&；空气。采用无导数BOBYQA算法进行扭矩优化，并基于Bertotti损耗模型评估AC（铁）损耗。结果表明，优化后的转矩传递能力提高了3.5 ~ 5.1倍，而损失仅增加了2.6 ~ 2.7倍。在所有配置中，扭矩的增长始终超过损耗的增长，这证实了能源效率和扭矩密度的整体改善。在测试的配置中，钢和SC组合产生了最大的绝对扭矩，而SC和空气配置由于没有铁损失而表现出最大的相对改善。这些结果表明，超导体可以在保持可控损耗水平的同时大幅提高转矩性能，有效地平衡转矩损耗。研究还表明，优化通过改变材料体积分布来改变有效传动比，强调了超导磁性齿轮的关键设计考虑因素。总的来说，这些发现为多目标优化策略提供了有价值的见解，并为未来的实验实现提供了坚实的基础。

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引用次数: 0

Thermodynamic analysis of thermally-driven dilution refrigerator in a confined cell 密闭槽内热驱动稀释制冷机的热力学分析

IF 2.1 3区工程技术 Q3 PHYSICS, APPLIED

Cryogenics

Pub Date : 2025-11-27 DOI: 10.1016/j.cryogenics.2025.104252

Zhiheng Li , Weijun Cheng , Yanan Wang , Wei Dai

Thermally-driven dilution refrigerator (TDR) in a confined cell uses a superleak to inject or extract superfluid ⁴He into or out of a chamber containing ³He, thereby achieving the expansion or compression of ³He, and the expansion of ³He produces cooling. Its typical structure can be regarded as a refrigerator (³He expansion cell) driven by a thermal compressor (⁴He reservoir). The ³He expansion cell are equipped with an external cooler (EC₁) to dissipate compression heat, and the ⁴He reservoir has a heater and external cooler (EC₂) to drive the superfluid ⁴He. In this paper, we use equations of the energy conservation and the ³He-⁴He dilution process, and the chemical potential conservation of ⁴He to establish two physical models for the entire system. Based on these models, the cooling performance of the system is predicted, and the coefficient of performance (COP) and the thermodynamic second law efficiency of the system are analyzed. Firstly, the cooling power of EC₂ determines the flow rate of superfluid ⁴He into the ³He expansion cell and the cooling power of TDR during the isothermal expansion processes. If the cooling power of EC₂ is fixed during isothermal expansion process, the cooling power of TDR shows a trend of gradual increase over time. Secondly, the thermodynamic second law efficiency of the system is less than 3 % with a typical cooling temperature of EC₁ and EC₂ are 0.3 K and 0.9 K, respectively. Both incomplete compression and expansion of ³He have an impact on the efficiency of the system. Finally, increasing the temperature of EC₁ will significantly reduce COP and thermodynamic second law efficiency and increase the amount of ³He and ⁴He required.

密闭细胞内的热驱动稀释制冷机（TDR）利用超泄漏将超流体4He注入或抽离含有3He的腔室，从而实现3He的膨胀或压缩，3He的膨胀产生冷却。其典型结构可以看作是由热压缩机（4He储热器）驱动的制冷机（3He膨胀箱）。3He膨胀槽配有外部冷却器（EC1）来散热压缩热，4He储液器配有加热器和外部冷却器（EC2）来驱动超流体4He。本文利用3He-4He稀释过程的能量守恒方程和4He的化学势守恒方程，建立了整个体系的两个物理模型。在此基础上，对系统的冷却性能进行了预测，并分析了系统的性能系数（COP）和热力学第二定律效率。首先，EC2的冷却功率决定了等温膨胀过程中超流体4He进入3He膨胀池的流量和TDR的冷却功率。如果等温膨胀过程中EC2的冷却功率固定，则TDR的冷却功率随时间呈逐渐增大的趋势。其次，系统的热力学第二定律效率低于3%，EC1和EC2的典型冷却温度分别为0.3 K和0.9 K。3He的不完全压缩和膨胀都会影响系统的效率。最后，提高EC1温度会显著降低COP和热力学第二定律效率，增加所需的3He和4He量。

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引用次数: 0

The offset and the performance of a valved linear compressor with anti-offset piston 带防偏置活塞的带阀直线压缩机的偏置与性能

IF 2.1 3区工程技术 Q3 PHYSICS, APPLIED

Cryogenics

Pub Date : 2025-11-20 DOI: 10.1016/j.cryogenics.2025.104251

Lei Ding , Xinquan Sha , Ran Hu , Qi Huang , Shaoshuai Liu , Zhenhua Jiang , Zhaohua Li , Hua Zhang , Yinong Wu

As a critical driving component of the Joule-Thomson (JT) throttling cryocooler for space applications, the output characteristics of the valved linear compressor (VLC) determine the overall efficiency of the cryocooler. Piston offset is an inherent characteristic of the VLCs. To improve the output capacity and efficiency of VLCs, valved linear compressor integrated with an anti-offset piston was developed in this study. The anti-offset piston can effectively suppress the piston offset, enhance VLC performance, and ensure the stable and efficient operation of the throttling cryocooler. Experimental verification was conducted to measure piston offset and the output characteristics of the VLC with anti-offset piston under various operating parameters. The results indicate that with the increase of the piston stroke, the offset establishment time is prolonged, the offset suppression effect is more obvious, and the effective stroke of the compressor is increased by nearly 40 %. Meanwhile, the suction pressure decreases, the discharge pressure increases, and the maximum pressure ratio is enhanced by 54.2 %. Under the same operating parameters, compared with the compressor without offset suppression, the anti-offset piston structure improves the efficiency of converting electric energy into mechanical energy and optimizes of compression thermodynamic cycle. The experimental results can provide important references for the development of piston offset suppression strategies.

作为用于空间应用的焦耳-汤姆逊（JT）节流制冷机的关键驱动部件，带阀线性压缩机（VLC）的输出特性决定了制冷机的整体效率。活塞偏置是VLCs的固有特性。为提高VLCs的输出能力和效率，研制了带防偏置活塞的带阀直线压缩机。防偏活塞能有效抑制活塞偏置，提高VLC性能，保证节流制冷机稳定高效运行。通过实验验证，测量了活塞在不同工作参数下的偏置量和抗偏置活塞VLC的输出特性。结果表明：随着活塞行程的增加，偏置建立时间延长，偏置抑制效果更加明显，压缩机有效行程提高了近40% %。同时，吸入压力减小，排出压力增大，最大压力比提高了54.2% %。在相同运行参数下，与无偏置抑制的压缩机相比，反偏置活塞结构提高了电能转化为机械能的效率，优化了压缩热力循环。实验结果可为活塞偏置抑制策略的开发提供重要参考。

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引用次数: 0

Influence of eccentric field cooling on levitation and guidance performance of HTS maglev based on Halbach-type PMG 偏心场冷却对基于halbach - PMG的高温超导磁悬浮悬浮和制导性能的影响

IF 2.1 3区工程技术 Q3 PHYSICS, APPLIED

Cryogenics

Pub Date : 2025-11-20 DOI: 10.1016/j.cryogenics.2025.104250

Yiming Zhou , Boyi Zhao , Yuchen He , Zhichuan Huang , Zigang Deng , Weihua Zhang

In practical research of high-temperature superconducting (HTS) maglev, a compulsory centering alignment operation between the superconducting levitator and permanent magnet guideway (PMG) is completed before field cooling (FC) process. However, errors in installation, positioning, and machining may lead to an eccentric state between the superconducting levitator and PMG before the FC process, which essentially means the geometric center of the internal HTS bulks is eccentric from that of the PMG. Therefore, this study investigates the effects of eccentric field cooling (EFC) on the levitation and guidance performance of HTS maglev. Specifically, a Halbach-type PMG is employed, and the eccentric displacement (ED) of bulks is set before FC process. Then during the levitation process, lateral displacement (LD) between bulks and PMG is applied to generate the guidance force. Results show that the EFC can adversely affect the levitation force, and this detrimental effect intensifies with increasing ED. During the LD process, when LD and ED are in the same direction, the reduction in levitation force increases with higher LD; conversely, when LD and ED are in opposite directions, the reduction decreases with increasing LD. Regarding the guidance force, at the initial of LD, appropriate EFC can enhance it, but excessive ED or LD values will negatively impact guidance force. These findings suggest that, in applications requiring high levitation performance, strict centering alignment operation before FC is essential. In contrast, for systems prioritizing guidance performance, appropriate applied EFC may be an effective optimization strategy.

在高温超导磁悬浮的实际研究中，超导悬浮体与永磁导轨之间必须在磁场冷却（FC）之前进行对中校准操作。然而，由于安装、定位和加工上的误差，可能导致超导悬浮体在FC过程之前与PMG之间出现偏心状态，即内部HTS块体的几何中心与PMG的几何中心偏心。为此，本文研究了偏心场冷却（EFC）对高温超导磁悬浮列车悬浮和导向性能的影响。具体而言，采用halbach型PMG，在FC处理前设置块体偏心位移（ED）。在悬浮过程中，利用悬浮体与悬浮微粒之间的侧向位移产生导向力。结果表明，EFC会对悬浮力产生不利影响，且这种不利影响随着ED的增加而加剧。在LD过程中，当LD和ED在同一方向时，随着LD的增加，悬浮力的降低幅度增大；相反，当LD和ED方向相反时，随着LD的增加，减小量减小。对于制导力，在LD初始，适当的EFC可以增强制导力，但过大的ED或LD值会对制导力产生负面影响。这些结果表明，在要求高悬浮性能的应用中，在FC之前进行严格的中心对准操作是必不可少的。相反，对于制导性能优先的系统，适当应用EFC可能是一种有效的优化策略。

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引用次数: 0

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