• 제목/요약/키워드: Heat Transfer Limit

검색결과 104건 처리시간 0.024초

원유펌프시스템의 열전달해석 및 냉각설계 (Heat Transfer Analysis and Cooling Design for Crude Oil Pump System)

  • 김완기;이준엽;권중록;김해천
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2008년도 추계학술대회B
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    • pp.2017-2022
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    • 2008
  • The crude oil pump system is the equipment for transporting crude oil and it consists of 3 major components, a motor and an impeller which discharge underground crude oil, a pipestack that transmits the cooling oil and power, and a cooling oil unit & junction box that provides cooling oil and electric power. When considering the system characteristics that it has to be installed at a depth of deeper than 100 m, a design technology for the efficient control of the heat occurring at a conductor and motor is necessary and it is the essential factor for ensuring system durability. In this paper, therefore, cooling oil flow has been calculated to satisfy the limit value of the system temperature by analyzing heat flow considering the related losses such as loss of conductor, contact resistor loss at the conductor connection, and operation loss of motor. And the operation temperature has been set up based on the temperature of crude oil and the heat of motor and conductor. Also, a design for cooling of crude oil pump system has been proposed by calculating the operation pressure loss and selecting the capacity of a cooling oil pump and a heat exchanger.

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열기관의 최대출력 사이클 (Maximum Power Output Cycle of Heat Engines)

  • 김수연;정평석;노승탁;김효경
    • 대한기계학회논문집
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    • 제14권3호
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    • pp.694-701
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    • 1990
  • 본 연구에서는 열기관의 출력이, 주어진 열원사이에서 구성되는 사이클의 형 태에 의존한다는 점에서 최대출력 사이클이 어떤 형태가 될 것인가하는 문제에 촛점을 맞추어 사이클을 해석하고, 최대출력을 구하고자 한다.

가스터빈 냉각 베인에서 감온액정을 이용한 과도적 열전달 특성에 관한 실험적 연구 (An Experimental Study on Transient Heat Transfer Characteristics of Gas Turbine Cooled Vane by Using Liquid Crystal Thermography)

  • 서남규;장태현
    • Journal of Advanced Marine Engineering and Technology
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    • 제30권1호
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    • pp.22-29
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    • 2006
  • Gas turbine engine among Principal internal combustion engines has been mainly applied as an aero and industrial Power plant. In order to increase its thermal efficiency. it has been raised their pressure ratio of compressor and the turbine inlet temperature. To operate above the limit temperature of turbine material, turbine nozzle vanes should be cooled. For this the cooling air is bled from the compressor section of 9as turbine. Meanwhile, to keep high thermal efficiency of 9as turbine, turbine vanes are to be cooled by using small cooling air Therefore, the complex cooling passages are requested to be designed and evaluated the effectiveness of vane cooling by measuring turbine vane temperature. But it is very difficult or impossible for us to measure local turbine temperatures at actual temperature When local heat transfer coefficients are known these can be calculated, therefore this study has been investigated on obtaining these coefficients of turbine vane at room temperature using TLC.

다공성 물질에 의한 예혼합기의 맥동연소에 관한 연구 (A Study on The Pulsating Combustion of Premixed Gas in a Tube with a Honeycomb)

  • 권영필;이동훈;현길학
    • 대한기계학회논문집
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    • 제14권3호
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    • pp.676-684
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    • 1990
  • 본 연구에서는 다공성 매질을 이용하여 예혼합기체를 맥동연소시킬 때의 진동 특성, 열적특성 및 연소특성에 관한 것이다. 먼저, 맥동의 모우드형상 및 발생조건 을 열전달과 음향이론을 바탕으로하여 예측하고 실험을 통하여 검토하였다. 또한 맥 동에 의한 화염형상의 변화를 가시화하여 관측하고, 온도분포 및 배기가스의 조성등을 측정하여 맥동 연소와 비맥동 연소를 비교 고찰하였다.

다분할 해석법에 의한 장형코일의 곡가공 연구 (A Study of Bending Using Long Type Coil by Discrete Method)

  • 이영화;장창두
    • 대한조선학회논문집
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    • 제45권3호
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    • pp.303-308
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    • 2008
  • The induction heating is more efficient for a plate bending because of its easy operation and control of working parameters, compared with the heating by a gas torch. The existing axis symmetric analysis method could neither handle initial curved plates nor be used in the optimization of coil shapes because of its limit of an axis symmetric coil shape. But the proposed method using some discrete part models and analysis processes could overcome these difficulties and show more accurate results in temperatures and deflections of flat or curved plates with initial curvature than those in the existing axis symmetric analysis method. This method is composed of the multi-disciplinary analyses such as an electro magnetic analysis, a heat transfer analysis and a deformation analysis based on inherent strain approach per each step. Traditionally, the coil shape in the induction heating is circular shape and it needs the moving process along heating lines. To overcome this, the 'Long Type Coil' with some linear parallel coils was proposed. It did not need the moving process along heating lines and reduced the heating process time. The results of experiments were compared with those of the simulation.

복사에 관여하는 유한 원통형 매질에서의 복사열 전달 (Radiative Heat Transfer in Radiatively Particpating Finite Cylindrical Media - Exact and P-N Solutions -)

  • 서인수;손종관;임승욱;이준식
    • 대한기계학회논문집
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    • 제12권6호
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    • pp.1428-1437
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    • 1988
  • 본 연구에서는 흡수, 방사 및 비등방성 산란을 하는 축대칭 유한원통형매질에 서의 형식해로부터 Gaussian Quadrature를 이용하여 수치적으로 엄밀해를 구하고 P-1 과 P-3근사해법을 통하여 얻어진 해와 비교하여 P-1과 P-3근사해법의 타당성을 검토하 였다.또한 매질의 광학두께, 산란알베도, 벽면방사율, 형상계수 등을 주요 파라미 터로 하여 이들의 영향에 대하여 고찰하였다.

Spent fuel simulation during dry storage via enhancement of FRAPCON-4.0: Comparison between PWR and SMR and discharge burnup effect

  • Dahyeon Woo;Youho Lee
    • Nuclear Engineering and Technology
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    • 제54권12호
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    • pp.4499-4513
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    • 2022
  • Spent fuel behavior of dry storage was simulated in a continuous state from steady-state operation by modifying FRAPCON-4.0 to incorporate spent fuel-specific fuel behavior models. Spent fuel behavior of a typical PWR was compared with that of NuScale Power Module (NPMTM). Current PWR discharge burnup (60 MWd/kgU) gives a sufficient margin to the hoop stress limit of 90 MPa. Most hydrogen precipitation occurs in the first 50 years of dry storage, thereby no extra phenomenological safety factor is identified for extended dry storage up to 100 years. Regulation for spent fuel management can be significantly alleviated for LWR-based SMRs. Hydride embrittlement safety criterion is irrelevant to NuScale spent fuels; they have sufficiently lower plenum pressure and hydrogen contents compared to those of PWRs. Cladding creep out during dry storage reduces the subchannel area with burnup. The most deformed cladding outer diameter after 100 years of dry storage is found to be 9.64 mm for discharge burnup of 70 MWd/kgU. It may deteriorate heat transfer of dry storage by increasing flow resistance and decreasing the view factor of radiative heat transfer. Self-regulated by decreasing rod internal pressure with opening gap, cladding creep out closely reaches the saturated point after ~50 years of dry storage.

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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영구자석형 초고속 전동기의 열특성 해석 (Analysis of thermal distribution for Permanent Magnet High Speed Motor)

  • 장석명;서정출;조한욱;정연호
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2004년도 하계학술대회 논문집 B
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    • pp.1073-1075
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    • 2004
  • Permanent magnet high-speed machines are small size compared with general motor of the same power and so must minimize generating heat, as well rotor structure is simple and strong for born centrifugal force. Especially, Material of each part is given thermal limit therefore temperature distribution vary important. In this paper, heat transfer coefficient of permanent magnet high-speed machines with 5-kW 40,000 rpm is calculated and temperature distribution due to power loss is predicted by finite element analysis.

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Micro-scale Thermal Sensor Manufacturing and Verification for Measurement of Temperature on Wafer Surface

  • Kim, JunYoung;Jang, KyungMin;Joo, KangWo;Kim, KwangSun
    • 반도체디스플레이기술학회지
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    • 제12권4호
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    • pp.39-44
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    • 2013
  • In the semiconductor heat-treatment process, the temperature uniformity determines the film quality of a wafer. This film quality effects on the overall yield rate. The heat transfer of the wafer surface in the heat-treatment process equipment is occurred by convection and radiation complexly. Because of this, there is the nonlinearity between the wafer temperature and reactor. Therefore, the accurate prediction of temperature on the wafer surface is difficult without the direct measurement. The thermal camera and the T/C wafer are general ways to confirm the temperature uniformity on the heat-treatment process. As above ways have limit to measure the temperature in the precise domain under the micro-scale. In this study, we developed the thin film type temperature sensor using the MEMS technology to establish the system which can measure the temperature under the micro-scale. We combined the experiment and numerical analysis to verify and calibrate the system. Finally, we measured the temperature on the wafer surface on the semiconductor process using the developed system, and confirmed the temperature variation by comparison with the commercial T/C wafer.