• Title/Summary/Keyword: 열적 성능

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Magnetic shield capability according to structure and material property of shield material in EML coating system (차폐재질 및 차폐구조에 따른 EML 코일 주변 자기장 차폐성능평가)

  • Song, Myeong-Gon;Jeong, Yong-Hwa
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2012.05a
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    • pp.263-263
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    • 2012
  • EML coating system은 코팅물질에 적절한 열을 가하기 위하여 상당히 높은 수준의 자기장을 이용한다. 이러한 이유로 인하여 EML 코일 주변에 자기장 차폐를 하지 않을 경우 주변의 금속성 물질에 전자기 유도 현상에 의하여 높은 수준의 와전류가 발생하여 결과적으로 열적인 손실을 발생하게 된다. 이러한 열적인 손실은 전체 시스템읠 효율 뿐 만 아니라 시스템의 안정적인 운전에도 좋지 않은 영향을 주게 된다. 이러한 영향을 방지하기 위하여 EML coil 주변은 자기 차폐를 하게 된다. 본 논문에서는 자기장 차폐용도로 사용하게 되는 자기차폐용 물질의 종류 및 구조에 따른 자기차폐성능 및 각 자기차폐물질에서의 발열을 전자기 해석을 통하여 도출 하였다.

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suspension preheater thermal efficiency 에 대한 종합

  • 한국양회공업협회
    • Cement
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    • s.48
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    • pp.20-28
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    • 1972
  • 본 논문은 Frankenberger씨의 논문을 번역한 것이다. preheater의 열적 성능 평가를 위해선 calcining degree, thermal efficiency 및 calorific efficiency를 이용하고 있으며 1kg의 dust circulation으로 30kcal/kg$\cdot$cli의 연료 소모량을 증가시키고 있어 4단 이상으로 증가시키는 문제도 대두 연구하고 있다.

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Modeling of the Thermal Behavior of a Lithium-Ion Battery Pack (리튬 이온 전지 팩의 열적 거동 모델링)

  • Yi, Jae-Shin
    • Journal of Energy Engineering
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    • v.20 no.1
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    • pp.1-7
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    • 2011
  • The performance and life-cycle costs of electric vehicle(EV) and hybrid electric vehicle(HEV) depend inherently on battery packs. Temperature uniformity in a pack is an important factor for obtaining optimum performance for an EV or HEV battery pack, because uneven temperature distribution in a pack leads to electrically unbalanced battery cells and reduced pack performance. In this work, a three-dimensional modeling was carried out to investigate the effects of operating conditions on the thermal behavior of a lithium-ion battery pack for an EV or HEV application. Thermal conductivities of various compartments of the battery were estimated based on the equivalent network of parallel/series thermal resistances of battery components. Heat generation rate in a cell was calculated using the modeling results of the potential and current density distributions of a battery cell.

위성발사체 로켓추진기관의 성능시험을 위한 디퓨져의 개념설계

  • 권경도;최열경;이원기;남평덕
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 1996.05a
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    • pp.255-262
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    • 1996
  • 고고도로 비행하는 위성발사체의 로켓모터는 압력이나 열적인 조건등이 지상과는 다른 저압환경에서 작동되기 때문에 그 성능이나 기능에 큰 영향을 받는다. 따라서 정확한 로켓의 추력과 자체의 신뢰성향상을 도모하기 위해서 로켓모터의 작동시험을 지상에서 저압환경을 모의하여 수행할 필요가 있다. 본 논문에서는 이러한 저압환경을 위한 시험장치의 종류 및 성능특성과 설계방법을 논하였다.

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Comparison of Rooftop Surface Temperature and Indoor Temperature for the Evaluation of Cool Roof Performance according to the Rooftop Colors in Summer: Using Thermal Infrared Camera Mounted on UAV (옥상 색상에 따른 쿨루프 성능평가를 위한 여름철 옥상 표면 및 실내온도 비교 분석 : 무인항공기에 장착된 열적외선 카메라를 이용하여)

  • Lee, Ki Rim;Seong, Ji Hoon;Han, You Kyung;Lee, Won Hee
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.37 no.1
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    • pp.9-18
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    • 2019
  • The intensity and the number of days of high temperature occurrence are also high and record heat occurred. In addition, the global warming phenomenon is intensifying globally, and especially in South Korea, the urban heat island phenomenon is also occurring due to rapid urbanization due to rapid industrial development. As the temperature of the city rises, it causes problems such as the comfort of the residential living and the cooling load. In this study, the cool roof performance is evaluated according to the roof color to reduce these problems. Unlike previous studies, UAV(Unmanned Aerial Vehicle) thermal infrared camera was used to obtain the surface temperature (white, grey, green, blue, brown, black) according to the rooftop color by remote sensing technique. As a result, the surface temperature of white color was $11{\sim}20^{\circ}C$ lower than other colors. Also air conditioning temperature of white color was $1.5{\sim}4.4^{\circ}C$ lower than other colors and the digital thermometer of white color was about $1.5{\sim}3.5^{\circ}C$ lower than other colors. It was confirmed that the white cool roof performance is the best, and the UAV and the thermal infrared camera can confirm the cool roof performa.

Development of PV/T for Performance Improvement of Photovoltaic System (태양광 발전의 성능향상을 위한 PV/T 시스템 개발)

  • Choi, Jung-Sik;Ko, Jae-Sub;Chung, Dong-Hwa
    • The Transactions of the Korean Institute of Power Electronics
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    • v.16 no.2
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    • pp.173-181
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    • 2011
  • This paper proposes photovoltaic thermal hybrid module to get the electrical and thermal performance of building integrated photovoltaic(BIPV) system. BIPV system is decreased the system efficiency because output of PV is decreased by the thermal rising on generating. In order to improve the efficiency of BIPV module, water cooling system is applied and generated thermal is used the warm water system. Water cooling system uses the flux control algorithm considering water temperature and power loss. Electrical and thermal performance of proposed photovoltaic thermal hybrid module is confirmed through the actual experiment and herby proved the valid of this paper.

A Study on Thermal Performance of Cement Mortar with PCM (PCM을 혼입한 시멘트 모르타르의 열적성능에 관한 연구)

  • Kim, Bo-Hyun;Lee, Han-Seung
    • Journal of the Korea Concrete Institute
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    • v.23 no.4
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    • pp.521-528
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    • 2011
  • Recently, environmental concerns and issues have become great concerns for the public. Therefore, this study is conducted with the objective of preventing energy depletion and $CO_2$ emission. PCM (Phase Change Materials) having latent heat characteristic is mixed in mortar to find a proper mix proportion. Also, the mortar properties and performances as well as a melting point of PCM when applied to air conditioning and heating conditions in at building environments were obtained by performing experiments. Also, latent heat and heat transfer characteristics were obtained from experiments by test of thermal performance to formulate temperature gradient about amount of heat transfer of PCM content using the Fourier's thermal equation. The study results can be used in the application of PCM in buildings and expected effect of air conditioning and heating energy.

Engineering-scale Validation Test for the T-H-M Behaviors of a HLW Disposal System (고준위폐기물 처분시스템의 열적-수리적-역학적 거동 규명을 위한 공학적 규모의 실증시험)

  • Lee Jae-Owan;Park Jeong-Hwa;Cho Won-Jin
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.4 no.2
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    • pp.197-207
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    • 2006
  • The engineering performance of a high level waste repository is significantly dependent upon the T-H-M behavior in the engineered barrier system. An engineering-scale test facility (KENTEX) was set up to validate the T-H-M behaviors in the buffer of a reference disposal system developed in the 2002. The validation tests started on May 31, 2005 and is now in progress. The KENTEX facility and validation test programme are introduced, and pre-operation calculations are also presented to give information on the sensitive location of sensors and operational conditions. This test will provide information (e.g., large-scale apparatus, sensors, monitoring system etc.) needed for 'in-situ' tests, make the validation of a T-H-M model for the T-H-M performance assessment of the reference disposal system, and demonstrate the engineering feasibility of fabricating and emplacing the buffer of a repository.

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