• Title/Summary/Keyword: in-vessel cooling

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The Literature Study on Macula among the Symptoms of Warm Factor Disease (온병(溫病)의 증상(症狀) 중(中) 반진(斑疹)에 관(關)한 문헌적(文獻的) 고찰(考察))

  • Jang, Yunjeong;Ryu, Sangchae;Kim, Jeongsoon;Jeon, Hoseong;Yu, Donghee;Kim, Nanyeong;Chong, Myongsoo;Lee, Kinam
    • Journal of Korean Medical Ki-Gong Academy
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    • v.11 no.1
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    • pp.80-116
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    • 2009
  • It studies into viewpoints of 7 doctors of Wenbing studies on macula. The results concerning characteristics, remedy and prevention of macula are as follows; Macule does not protrude on the surface of skin and does not have any color change for external stimulus, but rash out on the surface and becomes white when pushed. It becomes macule when the blood leaks beneath skin as stomach-heat of yangming enters into blood system and damages it. On the other hand, when heat enters lung meridian, penetrates beneath the skin and congeals inside the vessel, it becomes rash. When you combine symptoms of body and pulse with numbers, color, shape and distribution status of macula, you can diagnose the depth of rash, seriousness, the possibility of treatment and prognosis of macula. The remedy for macule consists of cooling heat of yaming, removing heat from the blood and relieving feverish rash, and the one for rash consists of facilitating meridian with aroma, expelling pathogenic factors from muscles with drugs of pungent flavor and cool nature and clearing away heat from the blood systems. It relieves the inhibited functional activities of lung-Ki, and helps extermination of rash as well as clearing heat of the vessel. Also, it is the most important to preserve resin of stomach for every treatment. It is good to avoid expelling pathogenic factors with drugs of pungent flavor and warm nature, raising drugs and invigorating drugs during treating macula. Moreover, the patients should not over dose cold-natured drugs and purgative therapy. There are common clinical symptoms of macula in advance, so right recognition of symptoms can contribute to prevention of macula.

Transient Simulations of Concrete Ablation due to a Release of Molten Core Material (방출된 노심용융 물질에 의한 콘크리트 침식 천이 모의)

  • Kim, H.Y.;Park, J.H.;Kim, H.D.;Kim, S.W.
    • Proceedings of the KSME Conference
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    • 2007.05b
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    • pp.3491-3496
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    • 2007
  • If a molten core is released from a reactor vessel into a reactor cavity during a severe accident, an important safety issue of coolability of the molten core from top-flooding and concrete ablation due to a molten core concrete interaction (MCCI) is still unresolved. The released molten core debris would attack the concrete wall and basemat of the reactor cavity, which will lead to inevitable concrete decompositions and possible radiological releases. In a OECD/MCCI project scheduled for 4 years from 2002. 1 to 2005. 12, a series of tests were performed to secure the data for cooling the molten core spread out at the reactor cavity and for the 2-D long-term core concrete interaction (CCI). The tests included not only separate effect tests such as a melt eruption, water ingression, and crust failure tests with a prototypic material but also 2-D CCI tests with a prototypic material under dry and flooded cavity conditions. The paper deals with the transient simulations on the CCI-2 test by using a severe accident analysis code, CORQUENCH, which was developed at Argonne National Laboratory (ANL). Similar simulations had been already per for me d by using MELCOR 1.8.5 code. Unlike the MELCOR 1.8.5, the CORQUENCH includes a melt eruption mode I and a newly developed water ingression model based on the water ingression tests under the OECD/MCCI project. In order to adjust the geometrical differences between the CCI-2 test (rectangular geometry) and the simulations (cylindrical geometry), the same scaling methodology as used in the MELCOR simulation was applied. For the direct comparison of the simulation results, the same inputs for the MELCOR simulation were used. The simulation results were compared with the previous results by using MELCOR 1.8.5.

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Preparation of Biodegradable Porous Calcium Metaphosphate Matrix (생분해성 다공질 Calcium Metaphosphate Matrix의 제조)

  • 이중환;김석영
    • Journal of Biomedical Engineering Research
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    • v.19 no.5
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    • pp.449-454
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    • 1998
  • It is well known that new tissue or blood vessel is grown into a porous calcium phosphate ceramics used as a bone graft substitute due to their excellent biocompatibility. In this study, the most chemically stable porous $\beta$-crystalline form in various forms of calcium metaphosphate, Ca(PO$_3$)$_2$is prepared by the controlled thermolysis of monocalcium phosphate, Ca(H$_2$PO$_4$)$_2$.The diameter of cylindrical pores formed during cooling was controlled by a holding time at the melting point of a monocalcium phosphate and by the change of a crystallization temperature, to obtain the most appropriate size (about 200$\mu$m) of pores for the application of bone substitutes and matricuts. It was observed that the increasing holding time at the melting point of monocalcium phosphate results in the decreases of cylindrical pore sizes.

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Recent Progress in Air-Conditioning and Refrigeration Research : A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2015 (설비공학회 분야의 최근 연구 동향 : 2015년 학회지 논문에 대한 종합적 고찰)

  • Lee, Dae-Young;Kim, Sa Ryang;Kim, Hyun-Jung;Kim, Dong-Seon;Park, Jun-Seok;Ihm, Pyeong Chan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.28 no.6
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    • pp.256-268
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    • 2016
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2015. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering were carried out in the areas of flow, heat and mass transfer, cooling and heating, and air-conditioning, the renewable energy system and the flow inside building rooms. Research issues dealing with air-conditioning machines and fire and exhausting smoke were reduced. CFD seems to be spreading to more research areas. (2) Research works on heat transfer area were carried out in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the economic analysis of GHG emission, micro channel heat exchanger, effect of rib angle on thermal performance, the airside performance of fin-and-tube heat exchangers, theoretical analysis of a rotary heat exchanger, heat exchanger in a cryogenic environment, the performance of a cross-flow-type, indirect evaporative cooler made of paper/plastic film. In the area of pool boiling and condensing, the bubble jet loop heat pipe was studied. In the area of industrial heat exchangers, researches were performed on fin-tube heat exchanger, KSTAR PFC and vacuum vessel at baking phase, the performance of small-sized dehumidification rotor, design of gas-injection port of an asymmetric scroll compressor, effect of slot discharge-angle change on exhaust efficiency of range hood system with air curtain. (3) In the field of refrigeration, various studies were carried in the categories of refrigeration cycle, alternative refrigeration/energy system, system control. In the refrigeration cycle category, a cold-climate heat pump system, $CO_2$ cascade systems, ejector cycles and a PCM-based continuous heating system were investigated. In the alternative refrigeration/energy system category, a polymer adsorption heat pump, an alcohol absorption heat pump and a desiccant-based hybrid refrigeration system were investigated. In the system control category, turbo-refrigerator capacity controls and an absorption chiller fault diagnostics were investigated. (4) In building mechanical system research fields, eighteen studies were reported for achieving effective design of the mechanical systems, and also for maximizing the energy efficiency of buildings. The topics of the studies included energy performance, HVAC system, ventilation, and renewable energies, piping in the buildings. Proposed designs, performance tests using numerical methods and experiments provide useful information and key data which can improve the energy efficiency of the buildings. (5) The field of architectural environment was mostly focused on indoor environment and building energy. The main researches of indoor environment were related to the user and location awareness technology applied dimming lighting control system, the lighting performance evaluation for light-shelves, the improvement evaluation of air quality through analysis of ventilation efficiency and the evaluation of airtightness of sliding and LS window systems. The subjects of building energy were worked on the energy saving estimation of existing buildings, the developing model to predict heating energy usage in domestic city area and the performance evaluation of cooling applied with economizer control. The studies were also performed related to the experimental measurement of weight variation and thermal conductivity in polyurethane foam, the development of flame spread prevention system for sandwich panels, the utilization of heat from waste-incineration facility in large-scale horticultural facilities.

Numerical Simulation of CNTs Based Solid State Hydrogen Storage System (탄소나노튜브 기반의 고체수소저장시스템에 관한 전산해석)

  • Kim, Sang-Gon;HwangBo, Chi-Hyung;Yu, Chul Hee;Nahm, Kee-Suk;Im, Yeon-Ho
    • Korean Chemical Engineering Research
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    • v.49 no.5
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    • pp.644-651
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    • 2011
  • Storing hydrogen in solid state hydride is one of the best promising methods for the future hydrogen economy. The total performance of such systems depends on the rate at which the amount of mass and heat migration is supplied to solid hydride. Therefore, an accurate modeling of the heat and mass transfer is of prime importance in optimizing the design of such systems. In this work, Hydrogen storage in Pt-CNTs hydrogen reactor has been intensively investigated by solving 2 dimensional mathematical models. Using a CFD computer software, systematic studies have been performed to elucidate the effect of heat and mass transfer during hydrogen charging periods. It was revealed that the optimized design of hydrogen storage vessel can prevent the increase of system temperature and the charging time due to the convective cooling effects inside the vessels at even high charging pressure. Because none has reported the critical issues of heat and mass transfer for CNT based hydrogen storage system, this work can support the first insight of the optimal design for solid state hydrogen storage system based on CNT in the near future.

Development of a Short-term Failure Assessment of High Density Polyethylene Pipe Welds - Application of the Limit Load Analysis - (고밀도 폴리에틸렌 융착부에 대한 단기간 파손 평가법 개발 - 한계하중 적용 -)

  • Ryu, Ho-Wan;Han, Jae-Jun;Kim, Yun-Jae;Kim, Jong-Sung;Kim, Jeong-Hyeon;Jang, Chang-Heui
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.39 no.4
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    • pp.405-413
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    • 2015
  • In the US, the number of cases of subterranean water contamination from tritium leaking through a damaged buried nuclear power plant pipe continues to increase, and the degradation of the buried metal piping is emerging as a major issue. A pipe blocked from corrosion and/or degradation can lead to loss of cooling capacity in safety-related piping resulting in critical issues related to the safety and integrity of nuclear power plant operation. The ASME Boiler and Pressure Vessel Codes Committee (BPVC) has recently approved Code Case N-755 that describes the requirements for the use of polyethylene (PE) pipe for the construction of Section III, Division 1 Class 3 buried piping systems for service water applications in nuclear power plants. This paper contains tensile and slow crack growth (SCG) test results for high-density polyethylene (HDPE) pipe welds under the environmental conditions of a nuclear power plant. Based on these tests, the fracture surface of the PENT specimen was analyzed, and the fracture mechanisms of each fracture area were determined. Finally, by using 3D finite element analysis, limit loads of HDPE related to premature failure were verified.

Preliminary Estimation of Activation Products Inventory in Reactor Components for Kori unit 1 decommissioning (고리1호기 해체시의 원자로 구조물에서의 방사회 생성물 재고량 예비평가)

  • Lee, Kyung-Jin;Kim, Hak-Soo;Sin, Sang-Woon;Song, Myung-Jae;Lee, Youn-Keun
    • Journal of Radiation Protection and Research
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    • v.28 no.2
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    • pp.109-116
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    • 2003
  • Based on the necessity to evaluate the activation products inventory during decommissioning lot domestic nuclear power plants, a preliminary estimation of the activation products inventory for Kori unit 1, which is getting close to the end of lifetime, was carried out with ANISN and ORIGEN2 code. In order to calculate neutron nux using ANISN code, the reactor was divided into 9 zones from core to bioshield concrete for radial direction. Also :he cross-section of main nuclides were calibrated with neutron flux in the reactor pressure vessel(RPV) region. The results showed that 95 % of tile total radioactivity in RPV from reactor shutdown to 10 years came from the nuclides of $^{55}Fe,\;^{59}Ni,\;^{63}Ni\;and\;^{60}Co$. And the total radioactivity with cooling of more than 50 years after decommissioning was no more than 0.2 % of at the time of shutdown. Considering the weight of RPV is 210 tons, the total radioactivity of RPV reached to $5.25{\times}10^{6}GBq$ at shutdown time. As compared with the total radioactivity of bioshield concrete at reactor shutdown time, the radioactivity after tooling more than 10 years was below 1 %.

A Study on the transition of Explosion to Eire of LPG and Its' Prevention (LP가스 폭발 후 화재 전이 현상 및 전이 방지에 관한 연구)

  • 오규형;이성은
    • Fire Science and Engineering
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    • v.18 no.2
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    • pp.20-26
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    • 2004
  • The purpose of this study is to investigate the transition mechanism and prevention mechanism of gas explosion to fire. Transition phenomena of explosion to fire of LPG in the explosion vessel of its size of TEX>$100 cm {\times} 60 cm {\times} 45 cm$ was visualized using the high speed video camera and the mechanism was analysed from the videograph. Newspaper size of $30cm {\times} 20cm$ was used for combustible sample in this experiments and LPG-air mixture was ignited by 10 ㎸ electric spark. Experimental parameter was gas concentration, size of vent area and position of combustible solid. Size of vent area were varied as $10cm {\times} 9cm, 13cm {\times} 10cm, 27cm {\times} 20cm, 40cm {\times} 27cm$, and the position of combustible was varied in 4 point. Carbon dioxide was used to study the prevention mechanism of explosion to fire transition of LPG. Based on this experiment we can find that transition possibility of explosion to fire on solid combustible from explosion is depends on concentration of LPG-air mixture and the exposure time of solid combustibles in high temperature atmosphere of flame and burnt gas. And cooling or inerting of the atmosphere after explosion can be prevent the transition of explosion to fire on solid combustibles from gas explosion.

Experimental Study of SBLOCA Simulation of Safety-Injection Line Break with Single Train Passive Safety System of SMART-ITL (SMART-ITL 1 계열 피동안전계통을 이용한 안전주입배관 파단 소형냉각재상실사고 모의에 대한 실험적 연구)

  • Ryu, Sung Uk;Bae, Hwang;Ryu, Hyo Bong;Byun, Sun Joon;Kim, Woo Shik;Shin, Yong-Cheol;Yi, Sung-Jae;Park, Hyun-Sik
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.40 no.3
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    • pp.165-172
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    • 2016
  • An experimental study of the thermal-hydraulic characteristics of passive safety systems (PSSs) was conducted using a system-integrated modular advanced reactor-integral test loop (SMART-ITL). The present passive safety injection system for the SMART-ITL consists of one train with the core makeup tank (CMT), the safety injection tank, and the automatic depressurization system. The objective of this study is to investigate the injection effect of the PSS on the small-break loss-of-coolant accident (SBLOCA) scenario for a 0.4 inch line break in the safety-injection system (SIS). The steady-state condition was maintained for 746 seconds before the break. When the major parameters of the target value and test results were compared, most of the thermal-hydraulic parameters agreed closely with each other. The water level of the reactor pressure vessel (RPV) was maintained higher than that of the fuel assembly plate during the transient, for the present CMT and safety injection tank (SIT) flow rate conditions. It can be seen that the capability of an emergency core cooling system is sufficient during the transient with SMART passive SISs.