Cryogenics最新文献_第4页

A novel approach to thermal insulation modelling in soft and medium vacuum insulation systems 软真空和中真空绝热系统绝热建模新方法

IF 1.8 3区工程技术 Q3 PHYSICS, APPLIED

Cryogenics

Pub Date : 2024-09-24 DOI: 10.1016/j.cryogenics.2024.103946

Gideon Volschenk , Michael O'Shea , Bryan Shaughnessy

The accuracy of vacuum-dependent models for predicting thermal performance of Multi-Layer Insulation (MLI) and other layered insulation systems is critical for the development of novel solutions in the aerospace and energy sectors, particularly long distance superconductors and cryogenic transfer lines. This paper presents a review of the current state of the art in cryogenic vacuum insulation systems and their associated modelling techniques and test methods. Current modelling techniques, namely the Lockheed and McIntosh MLI models, are compared to cryogenic, boil-off calorimeter test data for 3 types of MLI from the current literature. Both current models provide acceptable accuracy at high vacuum pressures but deviate from the test data when gas conduction becomes the dominant heat transfer mechanism (

K n \leq 1

). Neither of the current models follow the characteristic S-curve observed by researchers during insulation tests. This paper presents the introduction of a novel modelling approach for layered insulation systems though changes to the current state of the art, specifically at soft (

p_{v a c} \leq 7.5 \times 10^{5} mTorr

) and medium vacuum (

p_{v a c} \leq 7.5 \times 10^{2} mTorr

) pressures, by substituting the gas conduction term in both equations with alternative terms based on the system Knudsen number (Kn) and molecule mean free path (l). This results in a stronger pressure dependence across the vacuum regime. Both modified models exhibited the characteristic S-curve with significantly reduced errors over the entire range.

用于预测多层绝缘（MLI）和其他分层绝缘系统热性能的真空相关模型的准确性，对于航空航天和能源领域新型解决方案的开发至关重要，尤其是长距离超导体和低温传输线。本文综述了低温真空绝热系统及其相关建模技术和测试方法的现状。将当前的建模技术，即洛克希德和麦金托什多层绝缘模型，与现有文献中 3 种类型多层绝缘的低温沸腾量热计测试数据进行了比较。目前的两种模型在高真空压力下都能提供可接受的精确度，但当气体传导成为主要传热机制（Kn≤1）时，就会偏离测试数据。目前的两个模型都没有遵循研究人员在绝缘测试中观察到的 S 曲线特征。本文介绍了一种针对分层隔热系统的新型建模方法，该方法改变了当前的技术水平，特别是在软真空（pvac≤7.5×105 mTorr）和中真空（pvac≤7.5×102 mTorr）压力下，将两个方程中的气体传导项替换为基于系统努森数（Kn）和分子平均自由路径（l）的替代项。这使得整个真空系统对压力的依赖性更强。这两个修改后的模型都呈现出特征性的 S 曲线，在整个范围内误差明显减小。

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引用次数: 0

Progress in measuring techniques and thermal radiative properties of metals at cryogenic temperatures: A review 低温金属测量技术和热辐射特性的进展：综述

IF 1.8 3区工程技术 Q3 PHYSICS, APPLIED

Cryogenics

Pub Date : 2024-09-19 DOI: 10.1016/j.cryogenics.2024.103950

Abdul Rehman Hashmi , Bo Wang , Fatima Saadat , Zhihua Gan

In recent years, the development in measurement techniques of thermal radiative properties has attracted much attention to cryogenic applications, including space exploration, cryogenic research, medical applications, instrument design, planetary exploration and remote sensing, cryogenic storage and transportation. This paper discusses the importance of emissivity / absorptivity measurement, the factors they depend on, and the respective measurement methods, including calorimetric and radiometric. This paper also summarizes the published data on emissivity and absorptivity related to aluminum and stainless steel. It highlights the importance of surface treatment of materials, providing valuable insight into the significance of emissivity in cryogenic applications, which can serve as a reference for future research in this field.

近年来，热辐射特性测量技术的发展引起了低温应用领域的广泛关注，包括太空探索、低温研究、医疗应用、仪器设计、行星探测和遥感、低温储存和运输等。本文讨论了发射率/吸收率测量的重要性、它们所依赖的因素以及相应的测量方法，包括热量测量法和辐射测量法。本文还总结了已公布的与铝和不锈钢有关的发射率和吸收率数据。它强调了材料表面处理的重要性，对低温应用中发射率的意义提供了宝贵的见解，可作为该领域未来研究的参考。

引用次数: 0

Effect of temperature and heat input on helium isotope separation driven by an entropy filter 温度和热量输入对熵滤器驱动的氦同位素分离的影响

IF 1.8 3区工程技术 Q3 PHYSICS, APPLIED

Cryogenics

Pub Date : 2024-09-19 DOI: 10.1016/j.cryogenics.2024.103952

Liguo Wang , Qianxi Qu , Wanyin Zhao , Huan Chen , Niannian Dai , Peng Jia , Dong Xu , Laifeng Li

To understand the effect of temperature and heat input on helium isotope separation driven by an entropy filter, the thermomechanical flow of superfluid helium through an entropy filter for obtaining high purity ⁴He is experimentally investigated. For this method, there are two important indicators: separation flow (flow rate) and separation effect (³He concentration). The separation flow rate is examined at various temperatures ranging from 1.6 K to 1.9 K of feed helium. Different heat inputs (Q) are applied to the entropy filter outlet to drive superfluid ⁴He flowing through the porous element. The results demonstrate that the flow rate increases as the feed helium temperature decreases and heat input increases. Simultaneously, ³He diffusion is detected as the superfluid helium passes through the entropy filter. The concentration of ³He, filtered at different temperature ranging from 1.6 K to 1.9 K, are analyzed using HELIX SFT Static Vacuum Mass Spectrometer. The findings reveal that the ³He concentration decreases with an increase in the temperature of the feed helium bath. ³He concentration of feed helium is around

3.3 \times 10^{- 8}

. Specifically, the ³He concentration in the filtered helium at 1.6 K is approximately

3.2 \times 10^{- 10}

, while at 1.9 K, it reduced to

2.2 \times 10^{- 10}

. This suggests that ³He diffusion in He II is inversely proportional to the He II temperature from 1.6 K to 1.9 K, resulting in a lower ³He concentration at higher temperatures.

为了了解温度和热输入对熵过滤器驱动的氦同位素分离的影响，我们对超流体氦通过熵过滤器获得高纯度 4He 的热力学流动进行了实验研究。该方法有两个重要指标：分离流量（流速）和分离效果（3He 浓度）。在进料氦的 1.6 K 到 1.9 K 的不同温度下，对分离流速进行了研究。对熵过滤器出口施加不同的热输入（Q），以驱动超流体 4He 流经多孔元件。结果表明，随着进料氦气温度的降低和热输入的增加，流速也在增加。同时，当超流体氦通过熵过滤器时，检测到 3He 扩散。使用 HELIX SFT 静态真空质谱仪分析了在 1.6 K 至 1.9 K 不同温度下过滤的 3He 浓度。研究结果表明，3He 浓度随着进料氦浴温度的升高而降低。进料氦的 3He 浓度约为 3.3×10-8。具体来说，在 1.6 K 时，过滤氦中的 3He 浓度约为 3.2×10-10，而在 1.9 K 时，则降至 2.2×10-10。这表明，从 1.6 K 到 1.9 K，3He 在 He II 中的扩散与 He II 的温度成反比，导致在较高温度下 3He 浓度较低。

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引用次数: 0

Cryogenic thermosiphon used for indirect cooling of superconducting magnets 用于间接冷却超导磁体的低温热虹吸管

IF 1.8 3区工程技术 Q3 PHYSICS, APPLIED

Cryogenics

Pub Date : 2024-09-19 DOI: 10.1016/j.cryogenics.2024.103951

Weronika Głuchowska , Tomasz Banaszkiewicz , Matthias Mentink , Benoit Cure , Alexey Dudarev , Shuvay Singh

A thermosiphon is a thermodynamic phenomenon that facilitates the circulation of cryogen within a cooling system, relying solely on gravitational forces and phase change. This mechanism leverages the variations in the density of the cryogenic fluid throughout the entire cooling loop, creating a pressure gradient. This gradient serves as the primary driving force for the circulation of the cryogen. To negate the necessity of a circulation pump, it is crucial to determine the geometry of the cooling loop, the configuration of the thermosiphon, its height, and the vertical placement of the cryogen phase separator. This paper introduces a simplified computational model and the geometric calculations of the cryogenic thermosiphon for two distinct configurations of the indirect cooling loop for superconducting magnets.

热虹吸管是一种热力学现象，完全依靠重力和相变促进冷却系统内的低温循环。这种机制利用整个冷却回路中低温流体密度的变化，形成压力梯度。这种梯度是低温液体循环的主要驱动力。为了消除循环泵的必要性，确定冷却回路的几何形状、热虹吸管的配置、高度以及低温相分离器的垂直位置至关重要。本文介绍了一个简化的计算模型，以及超导磁体间接冷却回路两种不同配置的低温热虹吸管的几何计算。

引用次数: 0

Delamination analysis of the epoxy impregnated REBCO racetrack coil under thermal stress based on a 3D model 基于 3D 模型的热应力下环氧树脂浸渍 REBCO 赛道线圈分层分析

IF 1.8 3区工程技术 Q3 PHYSICS, APPLIED

Cryogenics

Pub Date : 2024-09-15 DOI: 10.1016/j.cryogenics.2024.103947

Yansong Shen , Zhidong Chen , Yunpeng Wei , Yongdou Liu

Superconducting coils made of Rare-Earth-Barium-Copper-Oxide (REBCO) coated conductor (CC) exhibit superior electromagnetic performance. Employing epoxy impregnation can improve the structural integrity of the superconducting coils. However, the delamination behavior is observed in the epoxy impregnated REBCO coil when the environment temperature cool from the room temperature to 77 K. In previous studies, there is a few researches on the delamination and mechanical behavior of the epoxy impregnated racetrack coil. Therefore, this study proposes a three-dimensional (3D) mechanical-thermal model which incorporates the cohesive zone material (CZM) to investigate the delamination mechanisms in epoxy impregnated REBCO racetrack coils during cooling. We found that the coil experienced a higher tensile radial stress at the semicircular part than the straight part during the cooling process. This leads to that the delamination area tends to appear initially in the semicircular part with large tensile radial stress. And the stress concentration generated at the edge of the delamination area in the semicircular part can cause the extension of the edge of the delamination area to the straight part. In addition, the influences of the thermal expansion coefficient (CTE) of the mandrel and overband on the coil delamination behavior are studied in this paper. It is found that the radial stress, the initial position of the delamination, and the degree of delamination are affected by the CTE of the mandrel and overband. And the delamination of the coil can be avoided by reducing the tensile radial stress of the coil through reducing the CTE of the mandrel or increasing the CTE of the overband. And the prevention of the delamination in the semicircular part can obviously avoid the occurrence of the delamination in the straight part of the racetrack coil.

由稀土钡铜氧化物（REBCO）涂层导体（CC）制成的超导线圈具有卓越的电磁性能。采用环氧树脂浸渍可以提高超导线圈的结构完整性。然而，当环境温度从室温冷却到 77 K 时，环氧树脂浸渍的 REBCO 线圈会出现分层行为。因此，本研究提出了一种包含内聚区材料（CZM）的三维（3D）力学-热学模型，以研究环氧树脂浸渍的 REBCO 赛道线圈在冷却过程中的分层机制。我们发现，在冷却过程中，线圈的半圆部分比直线部分承受了更大的拉伸径向应力。这导致分层区域往往首先出现在半圆部分，其径向拉伸应力较大。半圆形部分分层区边缘产生的应力集中会导致分层区边缘向直线部分延伸。此外，本文还研究了心轴和过带的热膨胀系数（CTE）对线圈分层行为的影响。研究发现，径向应力、分层初始位置和分层程度都会受到心轴和包带 CTE 的影响。通过降低心轴的 CTE 或增加包边带的 CTE 来降低线圈的径向拉伸应力，可以避免线圈分层。防止半圆部分的分层显然可以避免赛道线圈直线部分出现分层。

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引用次数: 0

Enhancing dynamic stability of HTS maglev systems with preloading method 利用预加载方法增强 HTS 磁悬浮系统的动态稳定性

IF 1.8 3区工程技术 Q3 PHYSICS, APPLIED

Cryogenics

Pub Date : 2024-09-10 DOI: 10.1016/j.cryogenics.2024.103945

Ye Hong, Zhichuan Huang, Zihan Wang, Jiwang Zhang, Jun Zheng

High temperature superconducting (HTS) bulks have strong flux pinning capabilities and are widely used in various fields. Their self-stabilizing characteristics also provide new ideas for ultra-high-speed rail transit. For HTS maglev systems, operational stability, curve negotiation and safety when subjected to external forces are very important. Due to the hysteresis effect of superconducting bulks, they do not always return to their initial positions after deviating from the levitated position in an alternative external magnetic field. In some cases, the levitation system can be destroyed. Studies have shown that preloading can enhance quasi-static levitation performance. Therefore, this paper conducts a detailed analysis of the quasi-static levitation and guidance forces of HTS bulks above a Halbach permanent magnet guideway (PMG) under conditions with and without preloading. Additionally, the dynamic responses of the HTS bulks under lateral or vertical pulsed excitations are studied, with a particular focus on the final equilibrium position offset after disturbance. The results indicate that preloading can suppress the attenuation of the levitation force, enhance the guidance performance, and raise stiffness in both lateral and vertical directions. It also effectively suppresses position deviation from disturbance and increases the maximum excitation force threshold for system instability. This study provides practical insights for HTS maglev applications.

高温超导（HTS）磁块具有强大的磁通钉扎能力，被广泛应用于各个领域。其自稳定特性也为超高速轨道交通提供了新思路。对于 HTS 磁悬浮系统来说，在受到外力作用时的运行稳定性、曲线协商和安全性都非常重要。由于超导块体的滞后效应，它们在另一个外部磁场中偏离悬浮位置后，并不总是能回到初始位置。在某些情况下，悬浮系统会被破坏。研究表明，预加载可以提高准静态悬浮性能。因此，本文详细分析了哈尔巴赫永磁导轨（PMG）上方的 HTS 球块在有预加载和无预加载条件下的准静态悬浮和导向力。此外，还研究了 HTS 球体在横向或纵向脉冲激励下的动态响应，尤其关注扰动后的最终平衡位置偏移。结果表明，预加载可以抑制悬浮力的衰减，增强制导性能，并提高横向和纵向的刚度。它还能有效抑制扰动后的位置偏差，提高系统失稳的最大激振力阈值。这项研究为 HTS 磁悬浮应用提供了实用见解。

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引用次数: 0

Diffusive solubility of nitrogen in Propane: Measurement from 96 K to 227 K at 0.1 MPa 氮在丙烷中的扩散溶解度：在 0.1 兆帕斯卡压力下从 96 K 到 227 K 的测量结果

IF 1.8 3区工程技术 Q3 PHYSICS, APPLIED

Cryogenics

Pub Date : 2024-09-07 DOI: 10.1016/j.cryogenics.2024.103944

Yihong Li , Zhaozhao Gao , Junxian Li , Zhikang Wang , Xiaoyu Fan , Wei Ji , Liubiao Chen , Junjie Wang

The burgeoning demand for large-scale energy storage has catalyzed the advancement of Liquid Air Energy Storage (LAES) technology. However, the liquid-phase propane cold storage process in LAES systems encounters a significant challenge: the dissolution of nitrogen protection gas in propane poses a substantial risk to both operational safety and performance. Given the dearth of data on the diffusive solubility of nitrogen in propane under constant atmospheric pressure and low-temperature conditions, this study constructed a testbench and conducted experiments within a temperature range of 96–227 K at a pressure of 0.1 MPa. The molar diffusive solubilities at 227 K, 176 K, 139 K, and 96 K are 0.030 %, 0.177 %, 0.297 %, and 0.962 %, respectively. Besides, this study also fits a calculation equation for the diffusive solubility of nitrogen in propane, which applies to the propane cold storage process in LAES systems.

大规模储能需求的不断增长推动了液态空气储能（LAES）技术的发展。然而，LAES 系统中的液相丙烷冷存储过程遇到了一个重大挑战：氮气保护气体在丙烷中的溶解对运行安全和性能都构成了巨大风险。鉴于缺乏有关恒定大气压力和低温条件下氮气在丙烷中的扩散溶解度的数据，本研究构建了一个测试平台，并在温度为 96-227 K、压力为 0.1 MPa 的范围内进行了实验。在 227 K、176 K、139 K 和 96 K 的摩尔扩散溶解度分别为 0.030 %、0.177 %、0.297 % 和 0.962 %。此外，这项研究还拟合了氮气在丙烷中的扩散溶解度计算公式，适用于 LAES 系统中的丙烷冷藏过程。

引用次数: 0

Numerical analysis on dynamic evolution characteristics of cryogenic cavitation through a Venturi tube 通过文丘里管的低温空化动态演化特性的数值分析

IF 1.8 3区工程技术 Q3 PHYSICS, APPLIED

Cryogenics

Pub Date : 2024-09-05 DOI: 10.1016/j.cryogenics.2024.103937

Guang Zhang , Kai Wang , Miao Yu , Abhilash Suryan , Zu Chao Zhu , Zhe Lin

Venturi tube can be used to measure the flow rate of stable single-phase fluid, which plays an important role in chemical industry, energy, aerospace and other fields. Due to the complex physical properties of cryogenic fluids, it is of great significance to study the cavitation characteristics of cryogenic fluids for practical engineering. In this paper, the modified Zwart cavitation model is used to study the evolution characteristics of cryogenic cavitation in Venturi tube and its relationship with turbulent kinetic energy under different pressure ratios by using dimensionless number P_r instead of cavitation number. The P_r value affects the development of cavitation to a large extent. When P_r = 1.3, cavitation is in a stable development mode. When P_r = 2.3, the development mode of cavitation changes from steady state to dynamic state. The temporal and spatial correlation between cavitation and vortex structure is studied by Q-criterion, and the geometric similarity between cavitation cloud and vortex structure in the development process is analyzed. The entropy production caused by velocity gradient change, turbulent dissipation and wall shear stress is further analyzed by entropy diagnosis method. The results show that the change of P_r value plays a leading role in the distribution of entropy production, and the generation and collapse of cavitation in the evolution process also have a great influence on the distribution of entropy production.

文丘里管可用于测量稳定单相流体的流速，在化工、能源、航空航天等领域发挥着重要作用。由于低温流体物理性质复杂，研究低温流体的空化特性对实际工程具有重要意义。本文采用改进的 Zwart 空化模型，用无量纲数 Pr 代替空化数，研究了不同压力比下文丘里管内低温空化的演化特征及其与湍流动能的关系。Pr 值在很大程度上影响空化的发展。当 Pr = 1.3 时，空化处于稳定发展模式。当 Pr = 2.3 时，空化的发展模式从稳定状态转变为动态状态。利用 Q 准则研究了空化与涡旋结构的时空相关性，分析了空化云与涡旋结构在发展过程中的几何相似性。通过熵诊断方法进一步分析了速度梯度变化、湍流耗散和壁面剪应力引起的熵产生。结果表明，Pr 值的变化对熵产生量的分布起主导作用，演化过程中空化的产生和崩溃对熵产生量的分布也有很大影响。

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引用次数: 0

Single-coated thick superconducting films for metal–organic deposition using trifluoroacetates 使用三氟乙酸盐进行金属有机沉积的单涂层厚超导薄膜

IF 1.8 3区工程技术 Q3 PHYSICS, APPLIED

Cryogenics

Pub Date : 2024-09-03 DOI: 10.1016/j.cryogenics.2024.103939

Takeshi Araki , Mariko Hayashi , Nao Kobayashi

Metal-organic deposition using trifluoroacetates (TFA-MOD) is known to yield uniform superconducting wires by a liquid growth mode. However, it has been difficult to prepare thick films because of drying stress during the calcining process. To avoid the drying stress, conventional crack-preventing chemicals such as H(CH₂)₈COOH are applied in conventional metal–organic deposition. However, large amounts of hydrogen atoms react with fluorine atoms during calcining process in TFA-MOD, and the consequent increased harmful carbon residue decreases superconductivity of the resulting films. To avoid the chemical reaction, new crack-preventing chemicals such as H(CF₂)₈COOH were applied to prepare single-coated thick films. A low ratio of hydrogen atoms decreases the chemical reaction and generates hydrogen fluorine gas, consequently suppressing the carbon residue. Above the calcining temperature, the crack-preventing chemical is decomposed into low-boiling-point chemicals such as CF₂CF₂ or CF₃CF₃. Consequently, single-coated thick film having low carbon residue and sufficient superconducting current per width was realized. For a long time, the authors have studied other possible candidate crack-preventing chemicals. Newly introduced fluorine ion measurement of decomposed materials during the calcining process revealed the nature of the crack-preventing chemicals. Based on the accumulated results, we have concluded that among over one million chemicals there are only two groups suitable for preparing single-coated thick superconducting films by TFA-MOD. One group is hydrogenated perfluoro-carboxylic acids such as H(CF₂)₈COOH and the other group is perfluoro di-carboxylic acids. With H(CF₂)₈COOH, using a single-coating process we were able to achieve a 560 nm-thick YBa₂Cu₃O_6.93 film having J_c of 4.70 MA/cm² (77 K,0T). Compared with a standard 150 nm-thick YBa₂Cu₃O_6.93 film having J_c of 7.70 MA/cm² (77 K,0T), the critical current per width is improved to about 227 %.

众所周知，使用三氟乙酸盐的金属有机沉积（TFA-MOD）可通过液态生长模式产生均匀的超导线。然而，由于煅烧过程中会产生干燥应力，因此很难制备厚膜。为了避免干燥应力，传统的金属有机沉积过程中会使用 H(CH2)8COOH 等常规防裂化学品。然而，在 TFA-MOD 的煅烧过程中，大量氢原子会与氟原子发生反应，有害碳残留的增加会降低薄膜的超导性。为了避免这种化学反应，我们采用了新型防裂化学品，如 H(CF2)8COOH 来制备单涂层厚膜。低比例的氢原子可减少化学反应并产生氟化氢气体，从而抑制碳残留。在煅烧温度以上，防裂化学物质会分解成低沸点化学物质，如 CF2CF2 或 CF3CF3。因此，实现了单涂层厚膜的低碳残留和足够的单位宽度超导电流。长期以来，作者一直在研究其他可能的候选防裂化学品。新引入的煅烧过程中对分解材料的氟离子测量揭示了防止裂纹化学物质的性质。根据积累的结果，我们得出结论，在一百多万种化学物质中，只有两类适合用 TFA-MOD 制备单涂层厚超导薄膜。一类是氢化全氟羧酸，如 H(CF2)8COOH，另一类是全氟二羧酸。对于 H(CF2)8COOH，我们采用单涂层工艺获得了 560 nm 厚的 YBa2Cu3O6.93 薄膜，其 Jc 为 4.70 MA/cm2（77 K，0T）。与 Jc 为 7.70 MA/cm2 （77 K，0T）的标准 150 nm 厚 YBa2Cu3O6.93 薄膜相比，单位宽度临界电流提高了约 227%。

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引用次数: 0

Absorption of liquid nitrogen into porous materials used in the cryogenic cold chain 低温冷链中使用的多孔材料对液氮的吸收

IF 1.8 3区工程技术 Q3 PHYSICS, APPLIED

Cryogenics

Pub Date : 2024-09-02 DOI: 10.1016/j.cryogenics.2024.103936

R.M.A. Spijkers, S. Vanapalli

A dry-shipper is a dewar used to transport frozen biomedical samples at cryogenic temperature. The inside of the dewar is lined with a porous material that absorbs and prevents the spillage of liquid nitrogen during transportation. In these porous materials vapor might be trapped during filling of the dry-shipper leading to a lower transport and storage time. The conditions under which the vapor is formed and the relationship with the porous material properties is not well understood. We studied the impact of the pore size distribution on the vapor retention in the porous materials by comparing liquid nitrogen absorption in aluminosilicate material with relatively large pores (1-100 μm) and calciumsilicate with small pores (∼0.45 μm). Both samples were immersed into saturated liquid nitrogen and a comparison of the absorbed liquid volume fraction with the porosity showed the calciumsilicate sample was completely filled with liquid, whereas the aluminosilicate contained a vapor fraction of about twenty percent. As a further investigation, we studied the absorption characteristics in subcooled liquid nitrogen. In this case, both materials absorbed liquid equivalent to their respective void fraction indicating no vapor pockets in the material. From these results, we propose a design property window for potential new porous materials for use in the dry-shippers.

干式运输船是一种用于在低温下运输冷冻生物医学样本的干燥箱。干燥箱内部衬有多孔材料，可吸收并防止液氮在运输过程中溢出。这些多孔材料在填充干式运输船时可能会截留蒸汽，从而缩短运输和储存时间。目前还不太清楚蒸汽形成的条件以及与多孔材料特性之间的关系。我们通过比较孔隙相对较大（1-100 μm）的硅酸铝材料和孔隙较小（∼0.45 μm）的硅酸钙材料对液氮的吸收情况，研究了孔隙大小分布对多孔材料中蒸汽截留的影响。将这两种样品浸入饱和液氮中，比较吸收液体的体积分数和孔隙率，结果显示硅酸钙样品中完全充满了液体，而硅酸铝样品中含有大约百分之二十的蒸气。作为进一步的研究，我们对过冷液氮中的吸收特性进行了研究。在这种情况下，两种材料都吸收了相当于各自空隙率的液体，表明材料中没有气穴。根据这些结果，我们为干式运输船中可能使用的新型多孔材料提出了一个设计特性窗口。

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引用次数: 0