• 제목/요약/키워드: Heat Transmission

검색결과 576건 처리시간 0.027초

최적 치차비 구현을 통한 치차열의 각도 위치 오차 설계 및 해석 (Design and Analysis of Gear Train with Composition of Optimum Gear Ratio)

  • 윤재윤
    • 한국정밀공학회지
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    • 제18권6호
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    • pp.102-108
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    • 2001
  • This paper addresses an analytical approach to the mechanical error analysis of gear train and tolerance design and manufacture of gear train in restricted space considering motor driving torque, driving system inertia, motor acceleration, motor rotor inertia and friction torque. The gear train is designed to have optimum gear ratio in restricted space and each gear is manufactured to have the lowest weight and each gear tooth is heat-treated to have robustness. Based on the small difference between the mechanical error analysis and measurement, gear train design with optimum gear ratio and restricted space and robustness is proposed.

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폭굉제어기에 의한 수소. 아세틸렌 산소 혼합가스의 폭굉제어 (Quenching Effects of Acetylene, Hydrogen-Oxygen Detonation)

  • 김한석;문정기
    • 한국안전학회지
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    • 제6권2호
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    • pp.31-36
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    • 1991
  • Quenching effects of acetylene and hydrogen into oxygen detonation by using detonation arrester [DA]are studied in this paper. The experiments were carried out in cylinderical shock tube. 5m long, 30mm dia., with stolchlometric ratio [SR]of each gas and 10-l20$\mu$ Cell Size of brass and Stainless Steel of DAs were installed in it To clarify arresting ability correlation with initial pressure, Pi, critical thickness, Tct, and shapes of supporting panel of DA are also investigated It is found that ­detonation velocities has most dependency on Pi, it shows notable changes around 0.5kgf/$\textrm{cm}^2$ for hydrogen, 0.15kgf/$\textrm{cm}^2$ for acetylen respectively, ­DA can be safety device able to arrest shock wave of detonation, ­over Tct flame transmission might be only the factor has to be considered, ­acetylene seems to be much more stronger detonation characteristics than hydrogen because of reaction heat.

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실시간 기상상태를 고려한 가용송전용량 산정 (Assessment of Available Transfer Capability (ATC) considering Real-time Weather Conditions)

  • 김동민;배인수;김진오
    • 전기학회논문지
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    • 제59권3호
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    • pp.485-491
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    • 2010
  • Total Transfer Capability (TTC) should be pre-determined in order to estimate Available Transfer Capability (ATC). Typically, TTC is determined by considering three categories; voltage, stability and thermal limits. Among these, thermal limits are treated mainly in this paper on the evaluation of TTC due to the relatively short transmission line length of Korea Electric Power Corporation (KEPCO) system. This paper presents a new approach to evaluate the TTC using the Dynamic Line Rating (DLR) for the thermal limit. Since the approach includes not only traditional electrical constraints but also real-time environmental constraints, this paper obtains more cost-effective and exact results. A case study using KEPCO system confirms that the proposed method is useful for real-time operation and the planning of the electricity market.

초전도 케이블의 퀜치 특성에 대한 계통안전성 제어방식 (Power System Security Control Method for Quench Characteristic of High-Temperature Superconducting Cable)

  • 이근준;황시돌;이정필;김창현;박희철
    • 한국조명전기설비학회:학술대회논문집
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    • 한국조명전기설비학회 2004년도 학술대회 논문집
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    • pp.375-380
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    • 2004
  • This paper presents the basic quench protection idea for the HTS(High-Temperature Superconducting) cable. In Korea power system, the transfer capability of transmission line is limited by the voltage stability, and HTS cable could be one of the countermeasure to solve the transfer limit as its higher current capacity and lower impedance[1]. However, the quench characteristic of HTS cable makes HTS cable to loss its superconductivity, and therefore change the impedance of the line and power system operating condition dramatically. This pheonominum threats not only HTS cable safety but also power system security, therefore a proper protection scheme and security control counterplan have to be established before HTS cable implementation. In this paper, the quench characteristics of HTS cable for the fault current based on heat balance equation was established and a proper protection method by FCL(Fault Current Limiter) was suggested.

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전류 조절로 파장 튜닝 가능한 편광상이 배치구조 기반 광섬유 빗살 필터 (Current-Controlled Wavelength-Tunable Fiber Comb Filter based on Polarization-Diversity Loop Configuration)

  • 최대호;이용욱
    • 조명전기설비학회논문지
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    • 제24권12호
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    • pp.33-37
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    • 2010
  • In this paper, we have demonstrated absolute wavelength tuning in an optical fiber comb filter based on a polarization-diversity loop configuration by controlling the current injected into enameled wires wound on polarization-maintaining fibers (PMF's), that is, adjusting Joule heat generated from enameled wires. The proposed fiber comb filter consists of a polarization beam splitter, a half-wave plate, a quarter-wave plate, and PMF's. And we observed wavelength change of spectral dips in transmission spectra of the fabricated filter by varying an input current applied to enameled wires. The absolute wavelength of the filter could be controlled in proportional to the square of the input current with good linearity, and the rate of the wavelength shift with respect to the input current was measured as 36.79[nm/$A^2$].

High $T_c$, Superconductors for Applications

  • Soh, Deawha;Fan, Zhanguo
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 2003년도 춘계종합학술대회
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    • pp.366-369
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    • 2003
  • High T$_{c}$ superconducting lines will be applied as key materials in the areas of power transmission line; magnetic levitation of vehicle; magnetic separation; magnetic energy storage and marine propulsion. A combination method of electrophoresis deposition and zone-melting for preparation of YBaCuO tape is proposed. The submicron particle powder of YBaCuO made by sol-gel method is used in the electrophoresis process. A 40~50${\mu}{\textrm}{m}$ thickness of YBaCuO film on Ag plate could be deposited in about three minutes. After deposition the film is rolled and heat treated in order to increase the density and the adhesion of the film to the Ag plate. Silver(Ag) and lead oxide(PbO) were added in the YBaCuO powder in order to reduce its melting point. The YBaCuO coating with controlled Ag and PbO contents was preliminarily zone-melted at about 945$^{\circ}C$.>.

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중 탄산 및 인산염 완층액 처리가 노계육의 조직구조 및 열안정성에 미치는 영향 (Effect of Bicarbonate and Phosphate Buffer Treatments on the Structure and Thermal Stability of Spent Layer Meat)

  • 이성섭;마스트 모리스 지
    • 한국식품과학회지
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    • 제23권6호
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    • pp.695-701
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    • 1991
  • 0.05 M 중탄산 나트륨 및 0.04 M 인산염 완충용액 (pH 8.3)으로 처리한 노계육 가슴살 및 다리살 시료의 경우 근섬유 단백의 불안정화를 시사하는 열변성 온도의 저하가 관찰되었다. 이러한 현상을 근섬유 단백중 95 Kdalton 및 55 Kdalton protein의 추출과 관련 가능성이 있는 것으로 판단되었으며 처리 시료의 근섬유구조 변화(Z-line의 파괴)와도 관련 가능성이 있는 것으로 판단되었다.

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방사율에 따른 진공유리 열관류율 수치해석 연구 (A Study on Numerical Analysis of Overall Heat Transmission Coefficient of Vacuum Glazing with Emissivity)

  • 황일선;이영림
    • 한국산학기술학회:학술대회논문집
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    • 한국산학기술학회 2012년도 춘계학술논문집 2부
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    • pp.756-758
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    • 2012
  • 인구증가와 지속적인 산업발전으로 인하여 건축이 매우 활발해지고 냉난방으로 인한 에너지 소비가 급증하게 되면서 효율적인 에너지 사용의 필요성이 크게 대두되었다. 건물에서 손실되는 에너지의 약 20~40%가 창문을 통해 손실이 일어나며 이를 해결하고자 현재 Low-E 유리, 복층유리등 다양한 방법들이 개발되어 사용하고 있으며 에너지 손실을 더욱 낮추기 위하여 진공유리가 개발 중이나 아직 보급은 이루어지지 않고 있다. 본 논문에서는 진공유리의 열관류율 측정 장치와 진공에서의 중요한 열전달 요인인 복사열전달이 진공유리 성능에 미치는 영향을 3차원 수치해석을 통하여 알아보았다.

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최적 기어비 구현을 통한 치차열의 설계, 제작 및 분석 (Design, manufacture and analysis of gear train with composition of optimum gear ratio)

  • 정상목;윤재윤
    • 한국군사과학기술학회지
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    • 제2권1호
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    • pp.132-138
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    • 1999
  • This paper addresses an analytical approach to the mechanical error analysis of gear train and tolerance design and manufacture of gear train in restricted space considering motor driving torque, driving system inertia, motor acceleration, motor rotor inertia and friction torque. The gear train is designed to have optimum gear ratio in restricted space and each gear is manufactured to have the lowest weight and each gear tooth is heat-treated to have robustness. Based on the small difference between the mechanical error analysis and measurement, gear train design with optimum gear ratio and restricted space and robustness is proposed

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MODELING AND SIMULATION FOR GAS PIPELINE SYSTEMS

  • Yoshida, Makoto;Kawato, Takashi;Fujita, Toshinori;Kawashima, Kenji;Kagawa, Toshiharu
    • 한국시뮬레이션학회:학술대회논문집
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    • 한국시뮬레이션학회 2001년도 The Seoul International Simulation Conference
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    • pp.335-339
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    • 2001
  • City gas is one of the most important necessities of daily city life and social infrastructures. City gas is delivered to every user through a pipeline network. The gas pressure in the pipeline is regulated by gas regulator. In the pressure control system, characteristics of gas pipeline is as important as characteristics of regulator. There are many reports about the transfer function model of the fluid pipeline. But suitable model about the gas transmission pipeline is not known. In this paper, as the transfer function model of the gas pipeline, new model considering the heat transfer between pipe wall and gas and temperature change of gas is proposed. To evaluate this model, frequency response tests are used. As the result, the proposed model shows a better agreement when compared with the experimental result than conventional models. The results show the effectiveness of the model.

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