• Title/Summary/Keyword: cryogenic

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Investigation on the tensile properties of glass fiber reinforced polymer composite for its use as a structural component at cryogenic temperature

  • Shrabani Ghosh;Nathuram Chakrobarty;Swapan C. Sarkar
    • Progress in Superconductivity and Cryogenics
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    • v.25 no.3
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    • pp.43-48
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    • 2023
  • Polymer composites, especially glass fiber reinforced polymer (GFRP) are finding ever-increasing applications in areas such as superconductivity, space technology, cryogenic rocket engines, and cryogenic storage vessels. Various components made of polymer composites are much lighter than their metallic counterparts but have equivalent strength for ultra-low temperature applications. In this paper, we have investigated the tensile properties of an indigenously prepared unidirectional cylindrical hollow composite tube for its use as a neck of the cryogenic vessel. XRD and SEM of the tube are completed before cryogenic conditioning to ascertain the fiber and resin distribution in the matrix. The result shows that for composites, after 15, 30, 45, and 60 minutes of cryogenic conditioning at 77K in a liquid nitrogen bath, the strength and modulus increase significantly with the increase of strain rate and reach the optimum value for 45 minutes of conditioning. The results are encouraging as they will be helpful in assessing the suitability of GFRP in the structural design of epoxy-based components for cryogenic applications.

LIQUID FLOW AND EVAPORATION SIMULATION OF CRYOGENIC FLUID IN THE WALL OF CRYOGENIC FLUID CARGO CONTAINMENT SYSTEM (극저온 유체 화물창 방벽 내의 액체유동 및 기화 시뮬레이션)

  • Park, Bum-Jin;Lee, Hee-Bum;Rhee, Shin-Hyung;Bae, Jun-Hong;Lee, Kyung-Won;Jeong, Wang-Jo;An, Sang-Jun
    • Journal of computational fluids engineering
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    • v.14 no.2
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    • pp.9-18
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    • 2009
  • The cargo containment system (CCS) for ships carrying cryogenic fluid consists of at least two levels of barriers and insulation layers. It is because, even though there is a small amount of leak through the primary barrier, the liquid tight secondary barrier blocks further leakage of the cryogenic fluid. However, once the secondary barrier is damaged, it is highly possible that the leaked cryogenic fluid flows through the flat joint made of glass wool and reaches the inner hull of the ship. The primary objective of the present study is to investigate the influence of the damage extent in the secondary barrier on the amount of leaked cryogenic fluid reaching the inner hull and the temperature distribution there. Simulation results using a computational fluid dynamics tool were compared with the experimental data for the leaked cryogenic fluid flow and evaporation in the secondary insulation layer. The experimental and computational results suggest that, unless there is a massive leak, the cryogenic fluid mostly evaporates in the insulation layer and does not reach the inner hull in the state of liquid.

A Study on the Structural Analysis of Cryogenic Submerged Pump (극저온용 액중펌프 구조해석에 관한 연구)

  • Chin, Do-Hun;Yi, Chung-Seob
    • Journal of the Korean Society of Industry Convergence
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    • v.23 no.5
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    • pp.727-733
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    • 2020
  • Recently, reciprocating cryogenic pumps are mainly developed for small-and-mid sized fuel supply systems. Centrifugal type pumps are not actively developed. Most cryogenic submerged pumps are imported. For transportation, cryogenic liquefied natural gas requires the liquid pump technology that can works in extreme evironments. In order to transport liquefied natural gas, it is necessary to apply pump technology. This is the fundamental research for developing the submerged pump technology applicable to the transportation and storage system equipment of cryogenic liquefied system. It tries to secure basic design materials through reverse-engineering in the cryogenic submerged pump development. Regarding materials, STS-304 and STS-431 which are stainless materials widely used in the cryogenic area are applied. Aluminum alloy is applied to impeller and upper manifolder and the pump rotates at the high speed of 6,000rpm.

Characteristics of Sub-cooled Nitrogen Cryogenic System for Applied High-Tc Superconducting Devices (고온초전도 응용기기용 과냉질소 냉각시스템의 냉각특성)

  • 강형구;김형진;배덕권;안민철;윤용수;장호명;고태국
    • Progress in Superconductivity and Cryogenics
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    • v.6 no.1
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    • pp.38-42
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    • 2004
  • The cryogenic system for 6.6 kV/200 A inductive superconducting fault current limiter (SFCL) was developed at Yonsei university in 2003. The sub-cooled nitrogen cryogenic system could be applied to not only SFCL but also many other applied high-Tc superconducting (HTS) devices like superconducting motor, superconducting generator and superconducting magnetic energy storage (SMES). Generally, the cooling capacity of GM-cryocooler depends on the load temperature. Therefore it is necessary to perform the cooling capacity test at no load condition to calculate the exact cooling power and heat load of cryogenic system. In this research, the cooling capacity test of GM-cryocooler was executed and the heat load of developed cryogenic system was calculated. The long run operation test results of sub-cooled nitrogen cryogenic system were successful in pressure and temperature condition. Moreover, the design and fabrication method of cryogenic system were introduced and the test results were described.

Micronization of Ibuprofen by Cryogenic Ball Milling (극저온 볼 밀링을 통한 Ibuprofen 분말의 마이크로화)

  • 조현갑;이경엽;백영남;박훈재;이상목
    • Journal of the Korean Society for Precision Engineering
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    • v.21 no.11
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    • pp.195-199
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    • 2004
  • For the present study, the cryogenic ball milling process was applied to make Ibuprofen microsized. The cryogenic ball milling was performed at low temperature of about -18$0^{\circ}C$ for 6 hours. The particle size distribution was determined before and after the cryogenic process. X-ray diffraction (XRD) measurement was made to determine the effect of cryogenic process on the crystallinity of Ibuprofen. The results showed that the size of Ibuproffn was reduced about 10 times by the cryogenic process. The degree of crystallinity of Ibuproffn was slightly reduced by the cryogenic process.

A Study on Cryogenic Line Chill Down Characteristics of LNG (극저온 LNG 배관냉각 특성에 대한 연구)

  • BYEONGCHANG, BYEON;KYOUNG JOONG, KIM;SANGKWON, JEONG;MO SE, KIM;SANGYOON, LEE;KEUN TAE, LEE;DONGMIN, KIM
    • Transactions of the Korean hydrogen and new energy society
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    • v.33 no.6
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    • pp.808-818
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    • 2022
  • In this research paper, we investigated the cryogenic line chill down characteristics of liquefied natural gas (LNG). A numerical analysis model was established and verified so that it can calculate the precise cooling characteristics of cryogenic fluid for the stable and safe utilization especially such as LNG and liquid hydrogen. The numerical modeling was programmed by C++ as an one-dimensional homogeneous model. The thermohydraulic cooling process was simulated using mass, momentum, energy conservation equations and appropriate heat transfer correlations. In this process, the relevant heat transfer correlations for nuclear boiling, transition boiling, film boiling, and single-phase heat transfer that can predict the experimental results were implemented. To verify the numerical modeling, several cryogenic line chill down experiments using LNG were conducted at the Korea Institute of Machinery & Materials (KIMM) LNG and Cryogenic Technology Center.

A new method fast measure cryogenic vessel heat leakage

  • LI, Zheng-Qing;LI, Xiao-Jin;LIU, Mo
    • Progress in Superconductivity and Cryogenics
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    • v.22 no.1
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    • pp.24-28
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    • 2020
  • Heat leakage is an important parameter to reflect heat insulated performance of cryogenic vessel. According to the current standard requirements, it needs to measure the daily evaporation rate to indicate heat leakage. The test needs-over 24h after cryogenic vessel in heat equilibrium as standard required, therefore test efficiency is poor and new efficient method is required to cut test time. First of all, the volume of instantaneous evaporated gas and heat leakage are calculated by the current standard corresponding to the maximum allowable daily evaporation rate of cryogenic vessel. Depending on the relationship between real daily evaporation rate and maximum allowable daily evaporation rate of cryogenic vessel, we designed a new test method based on the pressure changes over time in cryogenic vessel to determine whether its heat insulated performance meets requirements or not. Secondly, the heat transfer process was analyzed in measurement of cryogenic vessel, and the heat transfer equations of whole system were established. Finally, the test was completed in four hours; meanwhile the heat leakage and daily evaporation rate of cryogenic vessel are calculated basing on test data.

Helium guard system design for HIAF iLinac cryogenic distribution system

  • Xianjin Wang;Shuping Chen;Wen Jun;Dajun Fan;Liming Zhu;Yanan Lib;Xiaofei Niu;Junhui Zhang
    • Progress in Superconductivity and Cryogenics
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    • v.25 no.1
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    • pp.6-10
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    • 2023
  • 2 K superfluid helium cryogenic system is the crucial component of many large accelerators. When the cryogenic system is operating at 2K@3129Pa, many room-temperature parts are connected to superfluid helium via tubes. Air Leakage in these connections may lead to air contamination of the cryogenic system. Air contamination may cause equipment failure in cryogenic systems and, in extreme cases, render the entire accelerator system inoperable. Helium guard is a technique that guards against air contamination of these sub-atmospheric pressure connections in 2 K superfluid helium cryogenic system. This paper introduces a typical 2 K cryogenic distribution design for large accelerators, and make risk analysis of air contamination. Finally, the analysis of specific leakage points and detailed engineering design are presented, which may be used as a reference when designing of a 2 K superfluid helium cryogenic distribution system.

Effect of Packing Materials of Frozen Boar Semen on Sperm Characteristics and Reproductive Performance (동결정액 포장방법이 돼지정액의 성상 및 번식성적에 미치는 영향)

  • 김인철;이장희;김현종;이성호;박창식
    • Korean Journal of Animal Reproduction
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    • v.26 no.2
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    • pp.119-124
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    • 2002
  • This study was carried out to investigate the effects of packing materials of frozen boar semen to improve reproductive performance efficiency in pig. Boars were raised at Swine Artificial Insemination Center in National Livestock Research Institute, Sunghwan, Chungnam, Korea. We compared packing protocols for frozen boar semen among 5$m\ell$ maxi-straw, 5$m\ell$ cryogenic-vial, and aluminum-pack. Cryogenic-vial packing material showed similar sperm characteristics compared with maxi-straw packing material when the sperm was frozen above 15cm from liquid nitrogen and thawed at 52$^{\circ}C$ for 190 seconds. We investigated different thawing times to find out the optimal condition of freezing and thawing protocol with cryogenic-vial. Freezing above 15cm from liquid nitrogen and thawing at 52$^{\circ}C$ for 190 seconds were the optimal protocol compared with 120 and 150 seconds. However, normal acrosome rates did not show any differences among thawing times. Post-thawing results of maxi-straw in water at 52$^{\circ}C$ for 45 seconds had better total motility and curve linear velocity than those of cryogenic-vial in water 52$^{\circ}C$ for 190 seconds. However, there were no differences on straightness and normal apical ridge of sperm between maxi-straw and cryogenic vial. Non-return rate, farrowing rate and litter size of sows inseminated with frozen boar semen of commercial farms were higher in the maxi-straw than cryogenic-vial, but there were no significant differences between maxi-straw and cryogenic-vial. In conclusion, there were no significant differences between maxi-straw and cryogenic-vial and so, we may replace cryogenic-vial packing method instead of maxi-straw packing method by improvement of freezing and thawing rate.