Cryogenics最新文献_第10页

Magnetic properties and cryogenic magnetocaloric effect in α-Gd2(MoO4)3 compound α-Gd2(MoO4)3化合物的磁性能和低温磁致效应

IF 2.1 3区工程技术

Cryogenics Pub Date : 2024-06-06 DOI: 10.1016/j.cryogenics.2024.103875

Jiahao Gao , Zuhua Chen , Xinqi Zheng , Guochun Zhang , Shilin Yu , Zhenxing Li , Heng Tu , Jun Shen

{"title":"Magnetic properties and cryogenic magnetocaloric effect in α-Gd2(MoO4)3 compound","authors":"Jiahao Gao , Zuhua Chen , Xinqi Zheng , Guochun Zhang , Shilin Yu , Zhenxing Li , Heng Tu , Jun Shen","doi":"10.1016/j.cryogenics.2024.103875","DOIUrl":"https://doi.org/10.1016/j.cryogenics.2024.103875","url":null,"abstract":"<div><p>Magnetic refrigeration technology has received extensive attention due to its application prospects in various fields. The research of magnetocaloric materials is the basis for the development of magnetic refrigeration technology. In this study, the α-Gd<sub>2</sub>(MoO<sub>4</sub>)<sub>3</sub> was prepared by the high temperature solid state reaction. By X-ray diffraction characterization, α-Gd<sub>2</sub>(MoO<sub>4</sub>)<sub>3</sub> crystallizes in monoclinic structure (space group C12/c1). Furthermore, its magnetism and magnetocaloric effect are investigated. The magnetic ordering temperature of α-Gd<sub>2</sub>(MoO<sub>4</sub>)<sub>3</sub> is less than 1.8 K and there is a second-order phase transition. The maximum magnetic entropy changes are 20.8 and 32.7 J kg<sup>−1</sup> K<sup>−1</sup> under the field changes of 0–2 T and 0–5 T, respectively. Besides, the refrigeration capacity and relative cooling power are 142.0 and 190 J kg<sup>−1</sup> under field change of 0–5 T. These properties indicate that α-Gd<sub>2</sub>(MoO<sub>4</sub>)<sub>3</sub> is an excellent candidate for low temperature magnetic refrigeration.</p></div>","PeriodicalId":10812,"journal":{"name":"Cryogenics","volume":"141 ","pages":"Article 103875"},"PeriodicalIF":2.1,"publicationDate":"2024-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141294743","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

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Studies on temperature dependent dielectric properties of some insulators down to liquid helium temperatures 研究某些绝缘体随温度变化的介电性能，直至液氦温度

IF 2.1 3区工程技术

Cryogenics Pub Date : 2024-06-05 DOI: 10.1016/j.cryogenics.2024.103865

Pankaj Sagar , Kashif Akber

引用次数: 0

Investigation on the adsorption characteristics of activated carbons in the sub-Kelvin 4He sorption cooler 亚开尔文4He吸附冷却器中活性炭吸附特性的研究

IF 2.1 3区工程技术

Cryogenics Pub Date : 2024-06-01 DOI: 10.1016/j.cryogenics.2024.103861

Zeyu Li, Weifeng Deng

{"title":"Investigation on the adsorption characteristics of activated carbons in the sub-Kelvin 4He sorption cooler","authors":"Zeyu Li, Weifeng Deng","doi":"10.1016/j.cryogenics.2024.103861","DOIUrl":"10.1016/j.cryogenics.2024.103861","url":null,"abstract":"<div><p>The adsorption characteristics of the selected activated carbon have an important effect on the performance of the sub-Kelvin helium sorption cooler. In this paper, a test system for the adsorption amount of the carbons based on a G-M cooler was built, which has the advantages of being detachable and high gas seal performance. The adsorption isotherm of the three carbons (5.3 K-40 K, 0–0.6 MPa) for <sup>4</sup>He were experimentally tested, and the data were fitted according to the Dubinin theory. In addition, the calculation methods of sorption cooler were summarized and a model of cooling power prediction was established. Based on the above theoretical model and experimental data, a carbon with high specific surface area and excellent adsorption properties was selected as filler, and a prototype of <sup>4</sup>He sorption cooler was developed. The lowest temperature and holding time of the prototype are 923 mK and 8.47 h, respectively, in good agreement with the theoretical model. The model and the experimental method can provide reference for the design of sorption coolers at sub-Kelvin temperatures.</p></div>","PeriodicalId":10812,"journal":{"name":"Cryogenics","volume":"140 ","pages":"Article 103861"},"PeriodicalIF":2.1,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141132368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Performance prediction and optimization strategy for LNG multistage centrifugal pump based on PSO-LSSVR surrogate model 基于 PSO-LSSVR 代理模型的 LNG 多级离心泵性能预测与优化策略

IF 2.1 3区工程技术

Cryogenics Pub Date : 2024-06-01 DOI: 10.1016/j.cryogenics.2024.103856

Bo Liu , Wei Zhang , Feng Chen , Jie Cai , XunMing Wang , Yi Liu , JinLing Zhang , Qian Wang

{"title":"Performance prediction and optimization strategy for LNG multistage centrifugal pump based on PSO-LSSVR surrogate model","authors":"Bo Liu , Wei Zhang , Feng Chen , Jie Cai , XunMing Wang , Yi Liu , JinLing Zhang , Qian Wang","doi":"10.1016/j.cryogenics.2024.103856","DOIUrl":"10.1016/j.cryogenics.2024.103856","url":null,"abstract":"<div><p>The Multistage LNG cryogenic submersible pump is one of the crucial power equipment in LNG transport process. However, the high hydraulic losses and low efficiency of this pump make it necessary to optimize the structure of its impeller in order to reduce energy losses. In this study, an optimization strategy based on particle swarm optimization (PSO) and least squares support vector regression (LSSVR) machine is proposed to optimize the structure of impeller. The optimization of the impeller structure with the PSO-LSSVR method increased the head and efficiency of the LNG cryogenic submersible pump by 0.57% and 2.72%, respectively. Comparing the calculation results of PSO-LSSVR method with the CFD results, we found that the relative error between them don’t exceed 3%, which verified the calculation accuracy of the method. Then, an enstrophy dissipation theory is introduced to quantitatively analyze the pump energy loss. Comparing the impellers before and after optimization revealed that the maximum reduction in impeller energy loss was 18%.. The distribution and mechanism of vortex generation inside the impeller were analyzed with the Q-criterion and the relative vortex transport equation. The relative vortex transport equation revealed that the horseshoe vortex structure at the leading edge of the optimized impeller blade was suppressed, and the relative vortex stretching term and the Coriolis force term, which dominate the evolution of the vortex structure, were reduced. This study will provide related reference for the optimal design of Multistage LNG cryogenic submersible pumps.</p></div>","PeriodicalId":10812,"journal":{"name":"Cryogenics","volume":"140 ","pages":"Article 103856"},"PeriodicalIF":2.1,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0011227524000766/pdfft?md5=2152cc66659680421792bdbbee931fe8&pid=1-s2.0-S0011227524000766-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141039330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A modified J model for efficiently calculating the electromagnetic fields of ReBCO no-insulation pancake coils using an explicit–implicit hybrid algorithm 使用显式-隐式混合算法高效计算 ReBCO 无绝缘薄饼线圈电磁场的修正 J 模型

IF 2.1 3区工程技术

Cryogenics Pub Date : 2024-05-31 DOI: 10.1016/j.cryogenics.2024.103863

Yunkai Tang , Donghui Liu , Shouhong Shan , Dongke Li , Xiaohui Lin , Shuiliang Zhen , Chao Zhang , Huadong Yong

引用次数: 0

Recovery heat flux at superfluid helium boiling in a U-shape channel with a porous backfill 带有多孔回填层的 U 型通道中超流体氦沸腾时的恢复热通量

IF 2.1 3区工程技术

Cryogenics Pub Date : 2024-05-31 DOI: 10.1016/j.cryogenics.2024.103864

Yu. Yu Puzina, A.P. Kryukov

引用次数: 0

Variations in critical current density of TSSC cable under torsional and radial loads TSSC 电缆在扭转和径向负载下临界电流密度的变化

IF 2.1 3区工程技术

Cryogenics Pub Date : 2024-05-31 DOI: 10.1016/j.cryogenics.2024.103866

Yang Liu, Yuanwen Gao

{"title":"Variations in critical current density of TSSC cable under torsional and radial loads","authors":"Yang Liu, Yuanwen Gao","doi":"10.1016/j.cryogenics.2024.103866","DOIUrl":"https://doi.org/10.1016/j.cryogenics.2024.103866","url":null,"abstract":"<div><p>A 3D finite element mechanical-electric numerical model was constructed to analyze the mechanical-electric performance of TSSC cables under torsional and radial loads at 77 K. The results indicate that when subjected to torsional load, the tapes in the outermost region within the slot of TSSC cable initially exhibit a decreasing trend, gradually expanding towards the inner region. The magnitude of this decrease progressively diminishes in the direction from outer to inner. Conversely, under radial loading, the normalized critical current density of the tapes in the innermost region within the slot initially decreases and expands outward along the radius. The tapes in the middle region remain mostly unaltered, while the outer region follows a pattern of increasing from inside out and reaches its peak at layers 28 and 29. Moreover, under torsional loads, TSSC cables display a higher normalized critical current density in the counterclockwise direction compared to the clockwise direction. To enhance the critical current density performance of TSSC cables under torsional loads, it is suggested to appropriately reduce the pitch, decrease the width of superconducting tape, increase the number of stacked tapes, enlarge the width of the slot and the diameter of the diversion trench, as well as increase the inner diameter while decreasing the outer diameter of the helical core. The choice of material for helical cores is not significantly impactful. On the other hand, under radial loads, factors such as tape width, number of stacked tapes, slot width, diversion trench diameter, and inner and outer diameters of the helical core have similar effects. Additionally, increasing the pitch length or adding more slots can enhance the critical current density performance of TSSC cables. Selecting different materials for the helical core also contributes positively to this improvement.</p></div>","PeriodicalId":10812,"journal":{"name":"Cryogenics","volume":"141 ","pages":"Article 103866"},"PeriodicalIF":2.1,"publicationDate":"2024-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141243715","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The adsorption characteristics of helium under low temperature 低温条件下氦的吸附特性

IF 2.1 3区工程技术

Cryogenics Pub Date : 2024-05-26 DOI: 10.1016/j.cryogenics.2024.103862

Niannian Dai , Peng Jia , Qianxi Qu , Huan Chen , Liguo Wang , Yaran Shi , Rendong Guo , Dong Xu , Laifeng Li

引用次数: 0

Numerical and experimental investigation of cryogenic fluid flow characteristics on corrugated packing surfaces 波纹填料表面低温流体流动特性的数值和实验研究

IF 2.1 3区工程技术

Cryogenics Pub Date : 2024-05-20 DOI: 10.1016/j.cryogenics.2024.103860

Xiaoqin Zhi, Yixuan Teng, Huabin Zhou, Gaoming Zhan, Limin Qiu

{"title":"Numerical and experimental investigation of cryogenic fluid flow characteristics on corrugated packing surfaces","authors":"Xiaoqin Zhi, Yixuan Teng, Huabin Zhou, Gaoming Zhan, Limin Qiu","doi":"10.1016/j.cryogenics.2024.103860","DOIUrl":"https://doi.org/10.1016/j.cryogenics.2024.103860","url":null,"abstract":"<div><p>Cryogenic distillation is a significant method for producing pure oxygen and nitrogen gas. In the past, due to the high cost and difficulty of conducting cryogenic experiments, the structured packings used in cryogenic distillation are mainly developed and designed by referring to the testing results of room-temperature fluids. The real flow characteristics of cryogenic fluids on structured packings, such as flow pattern and wettability which significantly determines the distillation performance, have seldom been revealed. In this study, with the help of a three-dimensional CFD model and a visual experimental setup, the liquid nitrogen (LN<sub>2</sub>) flow characteristics within the geometric unit of a 45° inclined packing element were revealed detailedly under different liquid loads and crimping angles. Comparison studies were also conducted to show the different film flow characteristics between water and LN<sub>2</sub>. Additionally, optimization of the crimping angles based on 250Y structured packing was explored. Both simulation and experiment show that the flow pattern and wetting mechanism of the hydraulic test on water are different from those of LN<sub>2</sub> in the actual cryogenic distillation. The LN<sub>2</sub> has much better film flow performance than water due to its different physical properties. In addition, it is found that the crimping angle has a significant effect on the wetting area ratio. For LN<sub>2</sub>, the crimping angle of 90° can basically result in a high enough wetting area ratio, while for water, the crimping angle as large as 120° is needed to achieve a high wetting area ratio. It shows that testing and designing the structured packing with water as the main working medium will bring apparent errors in real cryogenic distillation process.</p></div>","PeriodicalId":10812,"journal":{"name":"Cryogenics","volume":"140 ","pages":"Article 103860"},"PeriodicalIF":2.1,"publicationDate":"2024-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141084339","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

3D printed suspension and its evaluation in an ADR refrigerator 3D 打印悬浮液及其在 ADR 冰箱中的评估

IF 2.1 3区工程技术

Cryogenics Pub Date : 2024-05-11 DOI: 10.1016/j.cryogenics.2024.103859

Yanan Li , Ping Liu , Peng Zhao , Ke Li , Wei Dai

{"title":"3D printed suspension and its evaluation in an ADR refrigerator","authors":"Yanan Li , Ping Liu , Peng Zhao , Ke Li , Wei Dai","doi":"10.1016/j.cryogenics.2024.103859","DOIUrl":"10.1016/j.cryogenics.2024.103859","url":null,"abstract":"<div><p>The salt pill suspensions play a critical role in determining the performance of adiabatic demagnetization refrigerators (ADR). Kevlar suspensions are commonly used to hold the salt pill in place and to minimize the thermal leak. However, traditional solutions such as tensioning the Kevlar and fixing it on mechanical frame with the help of epoxy or running it around a pulley are quite challenging. This paper presents an innovative suspension using 3D printing technology and a polyether ether ketone (PEEK) multi-ring suspension has been designed and tested. Numerical analysis shows that a single piece of the suspension may contribute about 1.10 μW thermal leak between 4 K and 0.3 K. To test its performance, a two-stage ADR is built with Gadolinium Gallium Garnet (GGG) as the first stage and chromium potassium alum (CPA) salt pill as the second stage which is supported by the PEEK suspension. The GGG stage is mainly used to provide an initial temperature for CPA stage. Typically, starting from 1 K@4 T, a no-load lowest temperature of 66.1 mK is achieved at a demagnetization rate of 0.005 T/s in the experiments. The thermal leak of the PEEK suspension with and without 1 K heat sink has been analyzed and compared, with the former one showing a big reduction of the thermal leak. This paper confirms the feasibility of PEEK as an ADR suspension material and provides a potential 3D printing method for complex suspension designs.</p></div>","PeriodicalId":10812,"journal":{"name":"Cryogenics","volume":"140 ","pages":"Article 103859"},"PeriodicalIF":2.1,"publicationDate":"2024-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141055761","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0