• Title/Summary/Keyword: freezing behavior

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An Experimental Study on Sea Water Freezing behavior in a Rectangular vessel Cooled From Above (구형용기의 상부면 냉각에 의한 해수 동결거동의 실험적 연구)

  • 최부홍
    • Journal of Advanced Marine Engineering and Technology
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    • v.22 no.4
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    • pp.529-537
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    • 1998
  • Currently as due to the rapid development of industry and increase in population we meet serious problems concerning the shortage and pollution of water. In the country many experts predict a shortage of water approaching 450 million tons by the year 2006. To cope with this serious problem it is necessary to construct desalination plants. In the adoption of a desalination system the most important factor is the cost of fresh water production,. In general LNG is stored in a tank as a liquid state below $-162^{\circ}C$. When it is serviced, however the LNG absorbs energy from a heat source and transforms to a high pressure gaseous state. During this process a huge amount of cold energy accumulated in cooling LNG is wasted. This wasted cold energy can be utilized to produce fresh water by using a sea water freezing desalination system. In order to develop a sea water freezing desalination system and to establish its design technique qualitative and quantitative data regarding the freezing behavior of sea water is required in advance, The goals of this study are to reveal the freezing behavior of sea water is required in advance. The goals of this study are to reveal the freezing mechanisms of sea water to measure the freezing rate and to investigate the freezing heat-transfer characteristics,. The experimental results will provide a general understanding of sea water freezing behavior in a rectangular vessel cooled from above.

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An Experimental Study on Sea Water Freezing Behavior in a Cooled Circular Tube (원관내의 해수동결거동에 관한 실험적연구)

  • 김명준
    • Journal of Advanced Marine Engineering and Technology
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    • v.22 no.5
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    • pp.680-686
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    • 1998
  • In the adoption of a desalination system the most important factor is the cost of fresh water pro-duction. In general LNG is stored in a tank as a liquid state below $-162^{\circ}C$ When it is serviced however the LNG absorbs energy from a heat source and it is transformed to a high pressure gaseous state. During this process a huge amount of cold energy accumulated in cooling LNG is wasted. This wasted cold energycan be utilized to produce fresh water by using a sea water freez-ing desalination system. in order to develop a sea water freezing desalination system and to estab-lish its design technique qualitative and quantitative data regarding the freezing behavior of sea water is required in advance. The goals of this study are to reveal the freezing mechanisms of sea water in a cooled circular tube to measure the freezing rate and to investigate the freezing heat-transfer characteristics. The experimental results provide a general understanding of sea water freezing behavior in a cooled circular tube.

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A Fundamental Study on Sea Water Freezing Behavior in a Rectangular Vessel Cooled from Below (구형용기의 하부면 냉각에 의한 해수 동결거동의 기초적 연구)

  • 김명준;길병래;김명환
    • Journal of Advanced Marine Engineering and Technology
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    • v.21 no.5
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    • pp.564-570
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    • 1997
  • The most important factor for the desalination system is the fresh water production cost dependent upon the possible energy source which should be obtained easily and with low price. Recently in Korea the demand of LNG, as a cheap and clean energy which does not cause an environmental problem, has sharply been increased. In general, LNG is storaged in a tank as a liquid state below -162 'C. When it is serviced, however, the LNG absorbs energy from a heating source and transforms to the gaseous state with high pressure. During this process a huge amount of cold energy accumulated in LNG is wasted. This waste cold energy can be utilized for producing fresh water from sea water using a sea water freezing desalination system. In order to develop a sea water freezing desalination system and to establish its design technique, a qualitative and quantitative data regarding the freezing behavior of sea water is needed in advance. The goal of this study, therefore, are to reveal the freezing mechanism of sea water, to measure the freezing rate, and to investigate the freezing heat-transfer characteristics. The experimental results help to provide a general understanding of the sea water freezing behavior in a Rectangular vessel cooled from below.

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AN EXPERIMENTAL STUDY ON SEA WATER FREEZING BEHAVIOR FOR DEVELOPMENT OF SEA WATER DESALINATION SYSTEM (해수 동결담수화장치 개발을 위한 해수동결에 관한 실험적 연구)

  • Park, D.S.;Kim, M.H.;Oh, C.
    • Journal of Advanced Marine Engineering and Technology
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    • v.25 no.6
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    • pp.1250-1259
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    • 2001
  • This study was experimentally performed to investigate sea water freezing behavior along parallel cooled plate with bubbly flow The experiments were carried out for a variety of parameter, such as sea water velocity, air-bubble flow rate, and cooled-plate temperature. The shape of freezing layer, freezing rate and salinity of frozen layer were observed and measured. It was found that the experimental parameters gave a great influence on the freezing rate and the salinity of the frozen layer.

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An Experimental Study on the Sea Water Freezing Behavior Around Parallel Cooled Plate in the Rectangular Duct (평행냉각평판을 갖는 구형용기내에서의 해수동결거동에 관한 연구)

  • Park, D.S.;Park, S.K.;Kim, M.H.;Yoon, S.H.;Oh, C.
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 2001.05a
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    • pp.249-257
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    • 2001
  • This study was experimentally performed to investigate sea water freezing behavior along parallel cooled plate with bubbly flow. The experiments were carried out for a variety of parameter, such as sea water velocity, air-bubble flow rate, and cooled-plate temperature. The shape of freezing layer, freezing rate and salinity of frozen layer were observed and measured. It was found that the experimental parameters gave a great influence on the freezing rate and the salinity of the frozen layer.

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A study on sea-water freezing behavior for ice maker for fishing boat (선박용 제빙장치의 개발을 위한 해수동결거동에 관한 연구)

  • Choi, Young-Gyu;Kim, Jung-Sik;Kim, Kyung-Kun;Oh, Cheol
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 2005.06a
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    • pp.233-238
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    • 2005
  • According to change of flow around a circular tube for freezing, measured a variety of salinity of frozen layer. This study was experimentally performed to investigate freezing behavior of sea water along a vertical cooled a circular tube with bubbly flow. The experiments were carried out for a variety of parameter, such as air-bubble method, cooled -tube temperature and air-flow rate. It was found that the experimental parameters gave a great influence on the freezing rate and the salinity of the frozen layer.

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An Experimental Study on Sea Water Freezing Behavior Along Horizontal Cooled Cylinder With Bubbly Flow (기포를 동반한 유동장에서의 냉각원과 주위의 해수동결에 관한 실험적 연구)

  • Park, D.S.;Yoon, S.H.;Kim, M.H.;Lee, Y.H.;Oh, C.
    • Journal of Advanced Marine Engineering and Technology
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    • v.25 no.4
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    • pp.825-832
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    • 2001
  • This study was experimentally performed to investigate freezing behavior of sea water along horizontal cooled a circular tube with bubbly flow. The experiments were carried out for a variety of parameter, such as sea water velocity, air-bubble flow rate, and cooled-tube temperature. The shape of freezing layer, freezing rate and salinity of frozen layer were observed and measured. And the flow patterns around cooled tube were visualized using the PIV to analyze the relationship between the flow structure and the freezing characteristics. It was found that the experimental parameters gave a great influence on the freezing rate and the salinity of the frozen layer.

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Hysteretic Behavior of RC Beams Exposed to Freezing and Thawing under Cyclic Loadings (철근콘크리트보의 동결융해 경험에 따른 반복하중하에서의 이력특성)

  • Jang, Gwang-Soo;Kim, Yun-Su;Seo, Soo_Yeon;Choi, Ki-Bong;Yun, Hyun-Do
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.11a
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    • pp.25-28
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    • 2008
  • Generally, reinforced concrete structures exposed to the outside temperature are affected by freezing and thawing process during winter and early spring. These freezing and thawing process can lead to the reduction in durability of concrete as cracking or surface spalling. This paper is to study the hysteretic behavior of RC beams exposed to freezing and thawing under cyclic loadings. To compare the difference in hysteretic behavior of RC Beams, limited tests were conducted under different types of damage and freezing and thawing cycles. For this purpose, six specimens were tested. It is thought that experimental results will be used as basic data to evaluate hysteretic behavior of RC beams exposed to freezing and thawing.

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Numerical Investigation into Behavior of Retaining Wall Subject to Cycles of Freezing and Thawing (동결-융해 반복작용에 노출되는 옹벽의 거동에 관한 수치해석 연구)

  • Yoo, Chung-Sik
    • Journal of the Korean Geotechnical Society
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    • v.29 no.1
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    • pp.81-92
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    • 2013
  • This paper presents the results of a numerical investigation into the behavior of retaining wall subject to cycles of freezing and thawing due to seasonal temperature change. The thermo-hydro-mechanical coupled finite element modeling strategy was first established to simulate the wall behavior. A series of finite element analyses were then performed on a range of conditions representing seasonal temperature change characteristics. The results indicated that the average freezing temperature and the number of cycles of freezing and thawing were the primary influencing factors for the wall behavior. Also revealed was that the duration of freezing period does not significantly affect the wall displacement and the lateral earth pressure, and that the earth pressure on the wall does not significantly change due to the freezing and thawing action suggesting that the increase in the wall displacement during the freezing and thawing action may be attributed to degradation of backfill due to the freezing and thawing action.

Laboratory investigation of unconfined compression behavior of ice and frozen soil mixtures

  • Jin, Hyunwoo;Lee, Jangguen;Zhuang, Li;Ryu, Byung Hyun
    • Geomechanics and Engineering
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    • v.22 no.3
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    • pp.219-226
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    • 2020
  • Unconfined compression test (UCT) is widely conducted in laboratories to evaluate the mechanical behavior of frozen soils. However, its results are sensitive to the initial conditions of sample creation by freezing as well as the end-surface conditions during loading of the specimen into the apparatus for testing. This work compared ice samples prepared by three-dimensional and one-dimensional freezing. The latter created more-homogenous ice samples containing fewer entrapped air bubbles or air nuclei, leading to relatively stable UCT results. Three end-surface conditions were compared for UCT on ice specimens made by one-dimensional freezing. Steel disc cap with embedded rubber was found most appropriate for UCT. Three frozen materials (ice, frozen sand, and frozen silt) showed different failure patterns, which were classified as brittle failure and ductile failure. Ice and frozen sand showed strain-softening, while frozen silt showed strain-hardening. Subsequent investigation considered the influence of fines content on the unconfined compression behavior of frozen soil mixtures with fines contents of 0-100%. The mixtures showed a brittle-to-ductile transition of failure patterns at 10%-20% fines content.