• Title/Summary/Keyword: temperature standards

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An Accelerated Degradation Test of Nuclear Power Plants Communication Cable Jacket (원자력 발전소용 통신케이블 자켓의 가속열화시험)

  • Jung, Jae Han;Kim, Yong Soo
    • Journal of Korean Society for Quality Management
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    • v.45 no.4
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    • pp.969-980
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    • 2017
  • Purpose: The purpose of this study was to estimate the lifetime, and verify the target lifetime at steady state temperature, of communication cable jackets used in nuclear power plants. Method: This study was completed according to test and analysis methods required by international standards. After measuring the residual elongation(%) of specimens at specific points in time with the accelerated degradation test, average failure time of each temperature was computed. Thus, the activation energy could be derived by applying the temperature-Arrhenius law to estimate cable jacket lifetime at steady state temperature. Results: The cable jacket lifetime was estimated as 363.8 years assuming a normal nuclear power plant operating temperature of $90^{\circ}C$. Conclusion: To ascertain stable operating conditions for a nuclear power plant, accelerated degradation tests were performed according to the Arrhenius law for components of the nuclear power plants. The lifetime was estimated from the degradation data collected during the accelerated degradation test.

Characteristics of tantalum nitride thin film resistors deposited on $SiO_2/Si$ substrate using D.C-magnetron sputtering

  • Cuong, Nguyen Duy;Phuong, Nguyen Mai;Kim, Dong-Jin;Kang, Byoung-Don;Kim, Chang-Soo;Yoon, Soon-Gil
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.07a
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    • pp.64-65
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    • 2005
  • The structural and electrical properties of the films are investigated as a function of nitrogen/argon ratio at room temperature and at various deposition temperatures. The phase changes as $Ta_2N$ or TaN in the films were observed as nitrogen/argon ratio increases from 3% to 25%. The phase changes were associated with a change in the resistivity and TCR (temperature coefficient of resistance) of the films. TCR values of the films deposited at room temperature and different nitrogen contents were negative, and strongly decreased with the increase in nitrogen/argon ratio. The Ta2N films deposited at nitrogen/argon ratio of 3% show improved TCR values and thermal stability with increasing deposition temperature. The $Ta_2N$ films grown at nitrogen/argon ratio of 3% and the temperature of $200^{\circ}C$ showed a TCR value of -47 $ppm/^{\circ}C$, which is close to near-zero TCR in the range of deposition temperature.

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Effect of Temperature on Nitritation using Effluent of Anaerobic Digester (혐기 소화조 유출수의 아질산화 반응에 온도가 미치는 영향)

  • Im, Jiyeol;Gil, Kyungik
    • Journal of Korean Society on Water Environment
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    • v.27 no.3
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    • pp.286-292
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    • 2011
  • Preparing for the Standards for Effluents which will be strengthen from 2012, many ways like remodellings and repairs of sewage treatment plant (STP) are considered. The treatment of the recycle water from the sludge treatment process contains high-strength organic compounds and nitrogen is considered as alternative. In the treatment of high-strength nitrogen, nitritation has more economic advantages than nitrification. In this study, lab-scale reactor was operated at the $35^{\circ}C$, $20^{\circ}C$ and $10^{\circ}C$ conditions using effluent of anaerobic digester to investigate the nitrogen removal by nitritation. Long-term stable nitritation was achieved at the $35^{\circ}C$, $20^{\circ}C$ but $10^{\circ}C$. In the stable nitritation states, nitrite conversion was higher at the high temperature of $35^{\circ}C$ than the room temperature of $20^{\circ}C$. Also shorter solid retention time (SRT) was needed to induce high nitrite conversion at the high temperature of $35^{\circ}C$. It was showed that temperature and SRT are important factors to induce nitritation.

A Study on the Establishment of the Optimal Temperature Limits for Man's Thermal Comfort in an Asymmetric Radiant Space (불균등 복사공간의 쾌적온도범위 설정에 관한 연구)

  • Sohn, Jang-Yeul;Kong, Sung-Hoon;Yun, Yong-Jin
    • The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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    • v.14 no.3
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    • pp.187-199
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    • 1985
  • The low-temperatured radiant heating System like a panel heating system is recognized as nice means to make comfortable indoor environment. Perhaps, 'Ondol' would be a typical example of the Panel heating system. Nevertheless. Occupants in a radiantly heated Space which has an asymmetric radiant field may feel thermally discomfort due to the asymmetric radiation. The aim of this Study is to suggest the fundamental technical data for establishing Standards of thermally comfortable environment when designing a radiant heating System. Thermal distribution of indoor environment and the skin temperature of the occupants were measured at experimental room in KIER (Korea Institute of Energy and Resources). Whole/Regional thermal and comfort Sensation votes of the occupants were taken simultaneously in order to investigate the relationships between thermal environmental factor and the occupants' responses. The effect of an asymmetric radiation on thermal environment and the occupants' responses was analyzed by using a v.r.t.(vector radiant temperature). By this means, the thermally neutral limits for the ambient air temperature and the floor surface temperature by the occupants' responses were Obtained. And the recommended temperature limits of the indoor surface were derived from the experimental work and the theory of radiant and will provide thermal neutrality for man without any discomfort on the part of the body.

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Permittivity Properties of Titania-fused Silica (Titania-fused Silica의 유전특성 분석)

  • Kim, Han-Jun;Lee, Rae-Duk;Semenov, Yu.P.;Han, Sang-Ok
    • Proceedings of the KIEE Conference
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    • 1999.07d
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    • pp.1803-1805
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    • 1999
  • The thermal expansion coefficient of the titania-fused silica glass$(TiO_2-SiO_2)$ called KLR-1.1 is known to $0{\pm}0.03$ ppm/K, while that of normal fused-silica glasses is about +0.5 ppm/K at room temperature. To analysis the dielectric properties of the KLR-1.1, the sample with diameter of 30 mm and thinkness of 1 mm is covered with gold film. Its relative permittivity and dissipation factor of KLR-1.1 is evaluated to $4.011{\pm}0.012(1\sigma)$ and $(4.86{\pm}0.02){\times}10^{-4}(1{\sigma})$ at 1 kHz respectively. The measurement techniques used and results are more discussed in this paper.

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Comparion of models and boundary conditions in fluid simulation of high density Inductively Coupled Plasma Sources included ion temperature equation (이온 온도 방정식이 포함된 고밀도 유도결합 플라즈마원 수송 시뮬레이션을 위한 모델 및 경계 조건 비교)

  • Kwon, Deuk-Chul;Yu, D.H.;Lee, J.K.;Yoon, N.S.;Kim, J.H.;Shin, Y.H.
    • Proceedings of the KIEE Conference
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    • 2004.07c
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    • pp.1924-1926
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    • 2004
  • 여러 그룹의 연구 결과로서 고밀도 유도결합 플라즈마원 유체 수송 시뮬레이션을 위해 다양한 경계 조건을 포함한 여러 가지 모델이 제시되어 왔다. 본 연구에서는 가능한 모델들과 경계 조건을 설정하여 FDM(finite difference method), up wind scheme, power-law scheme, die1ectric relaxation scheme[1]을 기반으로한 1차원 시뮬레이션을 통해 정확성과 수치 해석적 안정성 및 효율성 연에서 비교, 검토하였다.

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A Verification Test on Safety Standards of Portable Propane Gas Stove for Safe Camping Culture (안전한 캠핑 문화의 정착을 위한 야외용 프로판 연소기 안전기준 실증 연구)

  • Ahn, Hyun-Soo;Choi, Suel-Ki;Lee, Chang-Eon;Kim, Young-Gu
    • 한국연소학회:학술대회논문집
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    • 2014.11a
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    • pp.293-294
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    • 2014
  • In Korea, only butane gas could be used as fuel gas of the outdoor gas stove. However, butane is not vaporized well at low temperatures. For this reason, in the field, nozzle of the portable butane gas stove is converted illegally to use propane gas. Because vapor pressure of propane gas is higher than that of butane gas at same temperature, gas accidents such as gas leakage could be occurred. To prevent gas accidents and use portable propane gas stoves safely, international standards need to be analyzed and verification tests need to be performed with prototype stove. This study could suggest to revise standard for safety improvement with portable propane gas stoves.

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Calculation of the Reactance for a Magnetic Phase Created in a Steam Generator Tube Material

  • Ryu, Kwon-Sang;Jung, Jae-Kap;Son, Derac;Park, Duck-Gun
    • Journal of Magnetics
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    • v.15 no.2
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    • pp.70-73
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    • 2010
  • A magnetic phase is partly produced in a steam generator tube due to stress and heat, because steam generator tubes are exposed to high temperature, high pressure and radioactivity conditions. This adversely affects the safety of steam generator tubes. However, it is difficult to detect it using conventional eddy current methods. Therefore, a new type of probe is needed to separate the signals from the defects and magnetic phases. In this study, a new U-type yoke, which contained two types of coils, a magnetizing coil and detecting coil, was designed. In addition, the signal induced by the magnetic phase and defect in an Inconel 600 plate were simulated.

A Suggestion of Standards and factors applied Distributed Power System to electrical characteristic of HTS cable (배전계통 적용을 위한 초전도케이블의 전기적 특성요건과 규격검토)

  • Lee, Hyun-Chul;Lee, Geun-Joon;Hawg, Si-Dol;Son, Seung-Ho;Lim, Ji-Hyun;Jong, Sung-Won
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.165_166
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    • 2009
  • A HTS(High Temperature Superconductor) Cable is regarded as the most underground power to respond higher power density delivery system. This paper discussed electrical characteristic and standards of HTS Cable system. Various HTS cable characteristics are examined[3-5], ad compared with XLPE cable characteristics on possible distribution system environment. HTS cable is required to stabilize thermal condition for superconducting status, possible improper operating condition which affects quench, unbalanced, and harmonics impacts are discussed. HTS cable is customer designed cable which shall be implemented in special requirement of power system, the standard origination process requires to establish a series of methodology including design manufacturing, testing and installation.

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Magnetic Shielding Effect on Halbach Cylinder used in Magnetic Refrigerators

  • Baek, Un Bong;Lee, Jong Suk;Yu, Seong-Cho;Ryu, Kwon-Sang
    • Journal of Magnetics
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    • v.19 no.4
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    • pp.349-352
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    • 2014
  • The system for producing magnetic field constitutes an important component of magnetic refrigerator. Many researchers have directed significant effort to increase the magnetic field intensity, because the magnetocaloric effect at the Curie temperature increases with the power of 2/3 of the magnetic field. In this study, we report the simulation of the magnetic field intensity at polar axis of a Halbach cylinder (HC) by i) changing the length and thickness of the HC, ii) having with or without gap of the HC, and iii) surrounding the HC with a soft magnet shell, acting as a shielding. We simulated the field distribution of a HC with a finite size. Furthermore, the detailed numerical results of the magnetic field distribution and its dependence on shielding are presented in this study.