• 제목/요약/키워드: Cryogenic Process

검색결과 241건 처리시간 0.034초

초저온 산업용 액중펌프 임펠러 설계에 관한 연구 (A Study on the Impeller Design of a Submerged Cryogenic Pump)

  • 권병수;이치우;이중섭
    • 한국기계가공학회지
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    • 제15권6호
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    • pp.136-141
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    • 2016
  • The purpose of this study is to examine the basic design of a submerged cryogenic pump, which is a two stage impeller pump. We limited this study to the impeller design of the submerged pump. We calculated its velocity triangle based on the impeller blade configuration and, in order to check its natural frequency, we carried out a modal test using a finite element method (FEM) analysis. Basically, modal test results had quite similar to FEM analysis.

LNG 선박용 배관에 사용되는 Butterfly Valve의 구조 안정성 평가에 관한 해석 기법 (Analysis method on Structural Safety Evaluation of Butterfly Valve of Piping for LNG carrier)

  • 박영철;박한석;김시범
    • 한국기계가공학회지
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    • 제7권4호
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    • pp.76-81
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    • 2008
  • A cryogenic butterfly valve is used to transfer the liquefied natural gas (LNG) which temperature is $-162^{\circ}C$. This valve is core part in the piping system using LNG. This paper performed coupling analysis using FEM to evaluate safety of cryogenic butterfly valve. Flow analysis is calculated numerically the CAE and CFD methods are useful to predict the thermal matter and the inner flow field of the valve. Thermal analysis and structural analysis used ANSYS Workbench.

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인입 전류에 따른 실리콘(Silicon) 다이오드의 극저온 p-n 접합의 문턱 전압 특성 (Properties of p-n junction threshold voltage of Silicon diode by transport current in cryogenic temperature)

  • 이안수;이승제;이응로;고태국
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.2
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    • pp.864-867
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    • 2003
  • Since the development of semiconductors, various related research has been conducted. During research, silicon diodes have been commonly used because of their simplicity and low cost in the manufacturing process. This research deals with p-n junction threshold voltages from silicon diodes due to transport current at a cryogenic temperature. At a cryogenic temperature(77K) we could get minimum current which junction threshold voltage becomes constant. This is experimented on GPIB communication and it consist of programmable current source, multimeter which gauge the threshold voltage in a very low temperature caused by transport current from 5nA to 1mA and $LN_2$(77K) for coolant. This experiment is programmed all process using Measurement studio(Lab window) tool.

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다공성 매질에서 액화질소의 거동에 대한 연구 (STUDY ON BEHAVIOR OF LIQUID NITROGEN IN POROUS MEDIA)

  • 최성웅;이우일
    • 한국전산유체공학회지
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    • 제18권2호
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    • pp.17-25
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    • 2013
  • The process of flow through porous media is of interest a wide range of engineering fields and areas, and the importance of fluid flow with a change in phase arises from the fact that many industrial processes rely on these phenomena for materials process, energy transfer. Especially, the flow phenomena of cryogenic liquid subjected to evaporation is of interest to investigate how the cryogenic liquid behaves in the porous structure. In this study, thermo physical properties, morphological properties of the glass wool with different bulk densities in terms of its temperature-dependence and permeability behaviors under different applying pressure are discussed. Using the experimentally determined properties, characteristics of two main experimental results are investigated. In addition, simulation results are used to realize the cryogenic liquid's flow in porous media, and are compared with experimental results. By using the experimentally determined properties, more reasonable results can be suggested in dealing with porous media flow.

Development of a PLD heater for continuous deposition and growth of superconducting layer

  • Jeongtae Kim;Insung Park;Gwantae Kim;Taekyu Kim;Hongsoo Ha
    • 한국초전도ㆍ저온공학회논문지
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    • 제25권2호
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    • pp.14-18
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    • 2023
  • Superconducting layers deposited on the metal substrate using the pulsed laser deposition process (PLD) play a crucial role in exploring new applications of superconducting wires and enhancing the performance of superconducting devices. In order to improve the superconducting property and increase the throughput of superconducting wire fabricated by pulsed laser deposition, high temperature heating device is needed that provides high temperature stability and strong durability in high oxygen partial pressure environments while minimizing performance degradation caused by surface contamination. In this study, new heating device have been developed for PLD process that deposit and growth the superconducting material continuously on substrate using reel-to-reel transportation apparatus. New heating device is designed and fabricated using iron-chromium-aluminum wire and alumina tube as a heating element and sheath materials, respectively. Heating temperature of the heater was reached over 850 ℃ under 700 mTorr of oxygen partial pressure and is kept for 5 hours. The experimental results confirm the effectiveness of the developed heating device system in maintaining a stable and consistent temperature in PLD. These research findings make significant contributions to the exploration of new applications for superconducting materials and the enhancement of superconducting device performance.

분리막 공정과 LNG 냉열 및 심냉 증류를 이용한 전자급 고순도 이산화탄소의 분리 (Separation of Electronic Grade Highly Pure Carbon Dioxide Using Combined Process of Membrane, LNG Cold Heat Assisted Cryogenic Distillation)

  • 고영수;장경룡;김정훈;조영주;조정호
    • 한국수소및신에너지학회논문집
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    • 제35권1호
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    • pp.90-96
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    • 2024
  • In this paper, a new technology to obtain electronic grade, highly pure carbon dioxide by using membrane and liquefied natural gas (LNG) cold heat assisted cryogenic distillation has been proposed. PRO/II with PROVISION release 2023.1 from AVEVA company was used, and Peng-Robinson equation of the state model with Twu's alpha function to predict pure component vapor pressure versus temperature more accurately was selected for the modeling of the membrane and cryogenic distillation process. Advantage of using membrane separation instead of selecting absorber-stripper configuration for the concentration of carbon dioxide was the reduction of carbon dioxide capture cost.

극저온 압연에 의한 초세립 Al 5083 Alloy 제조 (Formation of ultrafine Grains in the Al 5083 Alloy by Cryogenic Rolling Process)

  • 이영범;심혜정;남원종
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2003년도 추계학술대회논문집
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    • pp.163-167
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    • 2003
  • The large deformation at cryogenic temperature would be one of the effective methods to produce large bulk UFG materials. The effects of annealing temperature 150∼300$^{\circ}C$, on microstructure and mechanical properties of the sheets received 85% reduction at cryogenic temperature were investigated. In comparison with those at room temperature. Annealing of 5083 Al alloy deformed 85%, at 200$^{\circ}C$ for an hour, results in the considerable increase of tensile elongation without the great loss of strength and the occurrence of equiaxed grains less than 300nm in diameter.

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상용 극저온 냉동기를 예냉기로 채택한 수소액화 시스템의 성능 해석 (Performance Analysis of a Hydrogen Liquefaction System using Commercial Cryogenic Refrigerators for Precooling)

  • 김승현;장호명;강병하
    • 한국수소및신에너지학회논문집
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    • 제9권2호
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    • pp.53-64
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    • 1998
  • Thermal analysis on a Linde-Hampson hydrogen liquefaction system using cryogenic refrigerators as precooling has been carried out. Three commercially available models of cryogenic refrigerators, such as CTI l020CP, CVI CGR009 and CVI CGR011, are considered in the performance analysis. The effect of ortho-para conversion process during hydrogen liquefaction is also studied in detail. The results obtained indicate that the optimal hydrogen mass flow rate and the optimal compressed pressure exist for the maximum hydrogen liquefaction rate. The optimal compressed pressure is increased in the range of 80 - 120 bar with an increase in the hydrogen mass flow rate. It is also found that better performance could be obtained with a cryogenic refrigerator, which produces high cooling capacity at precooling temperature in the range of 80 - 100 K.

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2상 극저온 열전달 과정 계산에서의 CFD 응용 (Application of CFD to tile Calculation of 2 Phase Cryogenic Heat Transfer Processes)

  • 유걸;악해파;정모;배철호
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2011년 춘계학술대회논문집
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    • pp.141-147
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    • 2011
  • A two-phase numerical model for plate-fin heat exchangers with plain fins and wave fins is studied incorporating the thermodynamic properties and the characteristics of fluid flow. The numerical simulations for the two fins in cryogenic conditions are earned out by employing a homogenous two-phase flow model with the CFD code ANSYS CFX. The heat transfer coefficients and the friction factor for nitrogen saturated vapor condensation process inside two types of plate fin heat exchanger are evaluated including the effects of saturation temperature (pressure), mass flow rate and inlet vapor quantity. The convective heat transfer coefficients and friction factors will be used for design of plate-fin type heat exchangers operating under cryogenic conditions.

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극저온 압연에 의한 초세립 5083 A1 Alloy 제조 연구 (Formation of Ultrafine Grains in 5083 Al Alloy by Cryogenic Rolling Process)

  • 이영범;심혜정;남원종
    • 소성∙가공
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    • 제13권2호
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    • pp.137-141
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    • 2004
  • The large deformation at cryogenic temperature is expected as one of the effective methods to produce large bulk ultrafine grained materials. The effects of annealing temperature, 150∼$300^{\circ}C$, on microstructures and mechanical properties of the sheets received 85% reduction at cryogenic temperature were investigated, in comparison with those at room temperature. Annealing of 5083 Al alloy deformed 85%, at $200^{\circ}C$ for an hour,. resulted in the considerable increase of tensile elongation without the great loss of strength and the occurrence of equiaxed grains less than 300nm in diameter.