• Title, Summary, Keyword: Liquid insulation

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Performance of a 5 L Liquid Hydrogen Storage Vessel (5 L급 액체수소 저장용기의 성능특성 연구)

  • KARNG, SARNG WOO;GARCEAU, NATHANIEL;LIM, CHANG MU;BAIK, JONG HOON;KIM, SEO YOUNG;OH, IN-HWAN
    • Transactions of the Korean hydrogen and new energy society
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    • v.26 no.3
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    • pp.234-240
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    • 2015
  • In the face of the world's growing energy storage needs, liquid hydrogen offers a high energy density solution for the storage and transport of energy throughout society. A 5 L liquid hydrogen storage tank has been designed, fabricated and tested to investigate boil-off rate of liquid hydrogen. As the insulation plays a key role on the cryogenic vessels, various insulation methods have been employed. To reduce heat conduction loss, the epoxy resin-based insulation supports G-10 were used. To minimize radiation heat loss, vapor cooled radiation shield, multi-layer insulation, and high vacuum were adopted. Mass flow meter was used to measure boil-off rate of the 5 L cryogenic vessel. A series of performance tests were done for liquid nitrogen and liquid hydrogen to compare with design parameters, resulting in the boil-off rate of 1.7%/day for liquid nitrogen and 16.8%/day for liquid hydrogen at maximum.

Electrical Insulation Characteristics of Insulators in Cryogenic Liquid for a HTS Apparatus (고온초전도 기기를 위한 극저온 액체 중 절연물의 전기적 특성)

  • Baek, Seung-Myeong;Kwag, Dong-Soon;Cheon, Hyeon-Gweon;Choi, Jae-Hyeong;Kim, Sang-Hyun;Kim, Hyun-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.263-264
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    • 2006
  • For practical electrical insulation design of high temperature superconducting (HTS) power apparatuses, knowledge of the dielectric behavior of insulators in cryogenic liquid such as liquid nitrogen ($LN_2$) is essential. So in this paper, we discussed experimental investigations of breakdown and V-t characteristics of several insulators such as Kapton and glass fiber reinforced plastic (GFRP) that are candidates of insulator for HTS apparatus in cryogenic liquid. And we investigated the degradation of these insulation samples after breakdown with the microscope and SEM photograph. Moreover, survival and hazard analysis were performed.

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The discharge characteristics for various electrode shapes under negative high-voltagein in Liquid $SF_6$ ((-)전압 인가시 액체 $SF_6$의 전극형상에 따른 절연파괴특성)

  • Choi, Eun-Hyuck;Park, Kwang-Seo;Kim, Lee-Kook;Lee, Kwang-Sik;Do, Dae-Ho;Kim, Jong-Whan
    • Proceedings of the KIEE Conference
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    • pp.2085-2087
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    • 2005
  • In this paper the experiments of insulation characteristics by temperature change of $SF_6$ gas and liquid $SF_6$ in model GIS(Gas Insulated Switchgear) were described. From this results, the breakdown voltage was increased with a drop of temperature and an increase of the inner pressure in model GIS. The ability of insulation in liquid $SF_6$ was higher than that of the highly pressurized $SF_6$ gas. A liquid $SF_6$ discharge characteristics was caused by bubble formed evaporation of liquid $SF_6$ and bubble caused by high electric emission. It is considered that these result are fundamental data for electric insulation design of superconductor and cryogenic application machinery which will be studied and developed in the future.

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The positive bubble effect in liquid $SF_6$ (액체 $SF_6$의 정기포현상(正氣泡現像))

  • Choi, Eun-Hyuck;Lee, Jae-Hyuck;Park, Kwang-Seo;Kim, Jong-Whan;Kim, Lee-Kook;Park, Won-Goo;Lee, Kwang-Sik
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • pp.151-154
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    • 2005
  • In this paper the experiments of insulation characteristics by temperature change of $SF_6$ gas and liquid $SF_6$ in model GIS(Gas Insulated Switchgear) were described. From this results, the breakdown voltage was increased with a drop of temperature and an increase of the inner pressure in model GIS. The ability of insulation in liquid $SF_6$ was higher than that of the highly pressurized $SF_6$ gas. A liquid $SF_6$ discharge characteristics was caused by bubble formed evaporation of liquid $SF_6$ and bubble caused by high electric emission. It is considered that these result are fundamental data for electric insulation design of superconductor and cryogenic application machinery which will be studied and developed in the future.

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Application of Bellows Cryogenic Insulation for Liquid Rocket Engines (액체로켓엔진의 벨로우즈 극저온 단열재 적용)

  • Kim, YoungJun;Jung, Eunhwan
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • pp.1057-1059
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    • 2017
  • In development of liquid-propellant rocket engine, engine gimbaling requires various types of bellows movements and cryogenic insulation is applied with movement-based design and material on each axial and circular bellows. Cryogenic insulation of Bellows for high pressure line and recirculation line are necessary to maintain cryogenic temperature for engien efficiency and protect from heat transfer and radiation of high temperature components during engine gimbaling.

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Polarization-dependence of liquid crystal alignment on an organic surface with ion beam irradiation

  • Choi, Dae-Sub;Han, Jeong-Min
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.208-208
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    • 2009
  • We used Brewster's Law to examine the mechanism of liquid crystal (LC) alignment on an organic insulation layer when subjected to ion-beam irradiation. Brewster's Law implies that the maximum rate polarized ray on a slanted insulation layers on the substrate and it illustrates the dependence of polarization and themechanical structure on the ion beam irradiation process. The pretilt angle of nematic LCs on the organic insulation surface was about $1.13^{\circ}$ for an ion beam exposure of $45^{\circ}$ for 1 minute at 1800eV. This shows the dependence of LC alignment on the polarization ratio in a slanted organic insulation layer.

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The analysis & comparative method on the breakdown voltage in $SF_6$ ($SF_6$ 상태에 따른 절연파괴전압 비교분석에 관한 연구)

  • Choi, Eun-Hyuck;Yoon, Dae-Hee;Park, Kwang-Soo;Park, Won-Goo;Joo, Jae-Hyun;Choi, Sang-Tae;Lee, Kwang-Sik
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • pp.335-338
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    • 2004
  • In this paper the experiments of insulation characteristics by temperature change of $SF_6$ gas and insulation characteristics about liquid $SF_6$ in GIS(Gas Insulated Switchgear) were described. From this result, at low temperature, the breakdown voltage was increased with a drop of temperature and an increase of the inner pressure in GIS. The ability of insulation in liquid $SF_6$ was higher than that of the highly pressurized $SF_6$ gas. A liquid $SF_6$ discharge characteristics was caused by bubble formed evaporation of liquid $SF_6$ and bubble when high voltage apply to electrode. Corona was happened to weak bubble and was proceed to new bubble breakdown.

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Dielectric Characteristics of HTS Cable (고온초전도 케이블의 유전 특성)

  • Kwag, Dong-Soon;Kim, Hae-Jong;Cho, Jeon-Wook;Seong, Ki-Chul;Kim, Sang-Hyun
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.64-68
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    • 2002
  • According to the increasing power demand for the future construction of many underground cables will be required. However, construction of new ducts for power cables will be more difficult. Therefore, research work for realizing the high temperature superconducting(HTS) cable has advanced, where the development of electrical insulating system at cryogenic temperature is one of the major researches. For an electrical insulation design of HTS cable, it is important to understand not only breakdown but also partial discharge and dielectric loss($tan{\delta}$) in liquid nitrogen/paper composite insulation system. In this paper, we investigated breakdown characteristics in liquid nitrogen/paper composite insulation system for the application to HTS cable. And, we studied the breakdown characteristics of the multi-layer and butt gap of the insulation papers in liquid nitrogen. Also, we measured dielectric loss($tan{\delta}$) of the mini-model Cable made of TERLAM IPP.

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A Study on the Thermal Conductivity of Inorganic Insulation Properties According to the Binder Types (바인더 종류에 따른 무기단열재의 열전도 특성에 관한 연구)

  • Jeon, Chanki;Lee, Jaeseong;Chung, Hoon;Park, Jongpil;Shim, Jaeyeong
    • Journal of the Society of Disaster Information
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    • v.12 no.3
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    • pp.286-291
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    • 2016
  • In this study, we conducted about the manufacture of a non-combustible inorganic insulation by replacing the binder type for satisfaction of thermal conductivity for developing a lightweight inorganic insulation. Thermal conductivity was measured using a machine of HFM-436. We made samples are inorganic insulation by using SH-1(liquid) of S company and SH-2(solids). By Mixing Pearlite and SH-4(Liquid) was produced as insulation sample 2. Each was shaped into a binder and pearlite in the frame. After complete drying, thermal conductivity was measured by using HFM-435. The thermal conductivity was determined using two different binder. We analyzed the effect on thermal conductivity in binder.

The Electric Insulation Characteristics of the Insulation Paper and Mini-model Cable in Liquid Nitrogen (액체질소에서 절연지 및 mini-model 케이블의 전기절연 특성)

  • 곽동순;김영석;정종만;김해종;김상현
    • Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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    • pp.224-227
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    • 2003
  • According to the increasing power demands for the power transmission of major cities, HTS power cables which have large current capacity and low power loss will be needed. In this paper we have studied breakdown voltage properties of paper/liquid composite insulating system for HTS cable insulation. And we measured the dielectric loss(tan$\delta$) of mini-model cable. From results, the insulation paper-ice composite insulation system is thought to be one of good candidate for the electrical insulating system at cryogenic temperature.

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