Cryogenics最新文献

{"title":"Performance prediction and optimization strategy for LNG multistage centrifugal pump based on PSO-LSSVR surrogate model","authors":"Bo Liu ,&nbsp;Wei Zhang ,&nbsp;Feng Chen ,&nbsp;Jie Cai ,&nbsp;XunMing Wang ,&nbsp;Yi Liu ,&nbsp;JinLing Zhang ,&nbsp;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":null,"pages":null},"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}

{"title":"A modified J model for efficiently calculating the electromagnetic fields of ReBCO no-insulation pancake coils using an explicit–implicit hybrid algorithm","authors":"Yunkai Tang ,&nbsp;Donghui Liu ,&nbsp;Shouhong Shan ,&nbsp;Dongke Li ,&nbsp;Xiaohui Lin ,&nbsp;Shuiliang Zhen ,&nbsp;Chao Zhang ,&nbsp;Huadong Yong","doi":"10.1016/j.cryogenics.2024.103863","DOIUrl":"https://doi.org/10.1016/j.cryogenics.2024.103863","url":null,"abstract":"<div><p>Rare-earth (Re)Ba₂Cu₃O_7−x (ReBCO) no-insulation (NI) coil is widely concerned due to its excellent electromagnetic and thermal properties. However, the presence of the turn-to-turn shunts in NI coils leads to that complexity of numerical simulation is increased. In this paper, a modified J model is proposed and the corresponding explicit–implicit hybrid algorithm is designed to calculate NI coils. The numerical results are in good agreement with the experimental data and the circuit model. The homogenization model is also proposed to simulate the large-scale NI coils in the background magnets. The modified J model has good accuracy and fast calculation speed, which can also be used to solve electromagnetic fields of insulation coils efficiently.</p></div>","PeriodicalId":10812,"journal":{"name":"Cryogenics","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141243716","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}

{"title":"Recovery heat flux at superfluid helium boiling in a U-shape channel with a porous backfill","authors":"Yu. Yu Puzina,&nbsp;A.P. Kryukov","doi":"10.1016/j.cryogenics.2024.103864","DOIUrl":"https://doi.org/10.1016/j.cryogenics.2024.103864","url":null,"abstract":"<div><p>The paper presents experimental data on the recovery heat flux during the boiling of superfluid helium (He II) on a flat heater located inside a U-shaped channel. The lower part of the channel is filled with monodisperse porous backfill. The paper includes information on the experimental cell, the data processing and synchronization technique, and the results of experiments conducted at different heater immersion depths and liquid temperatures. The paper presents also a mathematical description of heat transfer processes in superfluid helium for confined conditions. The calculated values are compared with experimental data. The effect of the porous backfill permeability on the recovery heat flux, including the case of a free channel is discussed. It is demonstrated that the increase in the heat flux in the channel initiates oscillations of the phase interface.</p></div>","PeriodicalId":10812,"journal":{"name":"Cryogenics","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141250899","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}

{"title":"Variations in critical current density of TSSC cable under torsional and radial loads","authors":"Yang Liu,&nbsp;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":null,"pages":null},"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}

{"title":"The adsorption characteristics of helium under low temperature","authors":"Niannian Dai ,&nbsp;Peng Jia ,&nbsp;Qianxi Qu ,&nbsp;Huan Chen ,&nbsp;Liguo Wang ,&nbsp;Yaran Shi ,&nbsp;Rendong Guo ,&nbsp;Dong Xu ,&nbsp;Laifeng Li","doi":"10.1016/j.cryogenics.2024.103862","DOIUrl":"https://doi.org/10.1016/j.cryogenics.2024.103862","url":null,"abstract":"<div><p>To study the separation of helium isotopes by cryogenic adsorption, figuring out the adsorption characteristics of helium isotopes at low temperature is necessary. In this paper, a cryogenic adsorption measurement device has been established. It consists of a cryostat with a GM Cryocooler as cold source, a Setaram gas sorption instrument and a temperature controller. The helium-4 adsorption isotherms were studied under different temperatures and pressures (15–300 K, 0–1.5 MPa) by volumetric method. The results showed that a little helium was adsorbed by activated carbon at 300 K and 77 K. The amount of adsorbed helium increased with the temperature decreased from 20 K to 15 K. At pressures lower than 0.2 bar, the adsorption capacity increased rapidly as the pressure increased. Besides, the isosteric heats of adsorption were obtained, which was around 515 J/mol and changed little. Moreover, the cryogenic adsorption results were analyzed by Langmuir model and Toth model.</p></div>","PeriodicalId":10812,"journal":{"name":"Cryogenics","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141308577","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}

{"title":"Numerical and experimental investigation of cryogenic fluid flow characteristics on corrugated packing surfaces","authors":"Xiaoqin Zhi,&nbsp;Yixuan Teng,&nbsp;Huabin Zhou,&nbsp;Gaoming Zhan,&nbsp;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 (LN₂) 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 LN₂. 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 LN₂ in the actual cryogenic distillation. The LN₂ 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 LN₂, 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":null,"pages":null},"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}

{"title":"3D printed suspension and its evaluation in an ADR refrigerator","authors":"Yanan Li ,&nbsp;Ping Liu ,&nbsp;Peng Zhao ,&nbsp;Ke Li ,&nbsp;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":null,"pages":null},"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}

{"title":"Asian Conference on Applied Superconductivity and Cryogenics (ACASC) 2023","authors":"Ho-Myung Chang","doi":"10.1016/j.cryogenics.2024.103858","DOIUrl":"https://doi.org/10.1016/j.cryogenics.2024.103858","url":null,"abstract":"","PeriodicalId":10812,"journal":{"name":"Cryogenics","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140918941","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}

{"title":"Joining of single-core ex-situ MgB2/Fe wires by termination architecture","authors":"T. Melišek,&nbsp;D. Berek,&nbsp;M. Búran,&nbsp;M. Bennar,&nbsp;P. Kováč","doi":"10.1016/j.cryogenics.2024.103857","DOIUrl":"https://doi.org/10.1016/j.cryogenics.2024.103857","url":null,"abstract":"<div><p>The development of reliable jointing technique is of great importance for the future of applied superconductivity, especially for superconducting magnets working in persistent mode. Superconducting joints with termination architecture between single-core not reacted <em>ex-situ</em> MgB₂/Fe wires were manufactured and tested. <em>I-V</em> characteristics of joints were measured at 4.2 K and 20 K for variable external fields and compared with <em>I-V</em> of joined wire. The ratio of joints critical current to that of parent conductors (<em>I</em>_c-joint/<em>I</em>_c-wire) has been evaluated and discussed. It was found that <em>I</em>_c-joint with termination architecture may be even larger than <em>I</em>_c-wire at high external field, but decreasing for lower fields. <em>I</em>_c-joint/<em>I</em>_c-wire = 0.8 was measured for the best joint at 20 K and low external field 1.5 T, which is promising for functional persistent switch.</p></div>","PeriodicalId":10812,"journal":{"name":"Cryogenics","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140947273","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}

{"title":"Experimental study on the flow electrification of liquid nitrogen in turbulent flow","authors":"Bowen Liu ,&nbsp;Xuehao Tian ,&nbsp;Yanzhong Li ,&nbsp;Yuan Ma ,&nbsp;Lei Wang ,&nbsp;Muhammad Aziz","doi":"10.1016/j.cryogenics.2024.103853","DOIUrl":"https://doi.org/10.1016/j.cryogenics.2024.103853","url":null,"abstract":"<div><p>Flow electrification occurs in all fluid flow scenarios involving solid–liquid interfaces. Due to electrostatic safety considerations, extensive research, both experimental and theoretical, has been conducted in the petroleum transportation field. However, research on flow electrification related to cryogenic fluids is relatively scarce, with even fewer experimental studies conducted. With the increasing use of cryogenic fluids such as liquid hydrogen and liquefied natural gas in aerospace and energy fields, there is an urgent need to expand the experimental database on cryogenic fluid flow electrification. In this context, a study focusing on cryogenic flow electrification using liquid nitrogen (LN₂) as the working fluid was initiated, accompanied by the establishment of a flow electrification experimental platform capable of capturing ultra-low electrical signals at cryogenic conditions. Three measurement methods were designed and implemented, including charge, potential, and current measurements. By comparing their performance, the streaming charge method was identified as the optimal choice due to the stability and linearity of the raw signal. Subsequently, extensive testing was conducted to analyze the effects of various parameters, including flow velocity, pipe diameter, pipe material, and pipe roughness, on flow electrification intensity. The conclusions drawn include: within the experimental measurement range, the current induced by flow turbulence is on the order of 10⁻¹² A for LN₂. Moreover, increasing pipe diameter and roughness exacerbate the charge transported. Among the four materials tested, PTFE exhibits the highest intensity of flow electrification, followed by aluminum and stainless steel, with copper showing the weakest effect. Finally, based on the experimental data obtained, a modified semi-empirical correlation formula for the streaming current was proposed, which can reflect the specific effects of flow velocity, pipe diameter, material, and pipe roughness. Our measurement research has significant implications for the study of flow electrification in LN₂ and its applications in aerospace and energy security fields.</p></div>","PeriodicalId":10812,"journal":{"name":"Cryogenics","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140893456","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}