• 제목/요약/키워드: Overall thermal performance

검색결과 250건 처리시간 0.031초

Conceptual Design for Accelerator-Driven Sodium-Cooled Sub-critical Transmutation Reactors using Scale Laws and Integrated Code System

  • Lee, Kwang-Gu;Chang, Soon-Heung
    • 한국원자력학회:학술대회논문집
    • /
    • 한국원자력학회 1998년도 춘계학술발표회논문집(1)
    • /
    • pp.660-665
    • /
    • 1998
  • The feasibility study on conceptual design methodology for accelerator-driven sodium-cooled sub-critical transmutation reactors has been conducted to optimize the design parameters from the scale laws and validates reactor performance with the integrated code system. A 1000 MWth sodium-cooled sub-critical transmutation reactor has been scale and verified through the methodology in this paper, which is referred to advanced Liquid Metal Reactor (ALMR). a Pb-Bi target material and a partitioned fuel are the liquid phases, and they are cooled by the circulation of secondary Pb-Bi coolant and by primary sodium coolant, respectively. Overall key design parameters are generated from the scale laws and they are improved and validated by the intergrated code system. Intergrated Code System (ICS) consist of LAHET, HMCNP, ORIGEN2, and COMMIX codes and some files. Through ICS the target region, the core region, and thermal-hydraulic related are analyzed once-through. Results of conceptual design are attached in this paper.

  • PDF

Synthesis, characterization, and antibacterial performance of Ag-modified graphene oxide reinforced electrospun polyurethane nanofibers

  • Pant, Bishweshwar;Park, Mira;Jang, Rae-Sang;Choi, Woo-Cheol;Kim, Hak-Yong;Park, Soo-Jin
    • Carbon letters
    • /
    • 제23권
    • /
    • pp.17-21
    • /
    • 2017
  • Polyurethane (PU) nanofibers containing graphene oxide (GO) and Ag doped functionalized reduced graphene oxide (Ag-RGO) were successfully prepared via the electrospinning technique. The uniform distribution of GO sheets along with Ag nanoparticle in the nanofibers was investigated by scanning electron microscopy and the elemental mapping technique. X-ray diffraction and thermal gravimetric analysis verified the presence of GO and Ag in the bicomposite nanofibrous mats. Antibacterial tests against Escherichia coli demonstrated that the addition of GO and Ag-RGO to the PU nanofiber greatly enhanced bactericidal efficiency. Overall, these features of the synthesized nanofibers make them a promising candidate material in the biomedical field for applications such as tissue engineering, wound healing, and drug delivery systems.

진동세관형 히트파이프를 이용한 태양열 집열기 개발에 관한 기초연구(I);작동유체의 내부 충진율과 경사각도의 영향 (Study on development of Solar Collector using Oscillating Capillary Tube Heat Pipe)

  • 김태훈;김종수;하수정;임용빈
    • 대한기계학회:학술대회논문집
    • /
    • 대한기계학회 2004년도 춘계학술대회
    • /
    • pp.1394-1399
    • /
    • 2004
  • Recently solar energy is representative in the technology development and spread of alternative energy. Specially in condition of solar collectors, they have had very various shape. This paper reports experimental study about the application of Oscillating Capillary Tube Heat Pipe to flat-plate solar collector. In conclusion, overall temperature distribution of OCHP was investigated by charging ratio and inclination angle. Respective charging ratio is 15%, 20%, 40% and respective inclination angle is horizontal, $30^{\circ}$, $45^{\circ}$, $60^{\circ}$, perpendicular. As a result of experiment, charging ratio 20% heat pipe has shown the most uniform temperature distribution and also performance of heat transfer has been the best.

  • PDF

THERMAL SATABILITY AND MAGNETORESISTANCE OF TOP SPIN VALVE WITH SYNTHETIC ANTIFERROMAGNET CoFe/Ru/CoFe/IrMn

  • J. Y. Hwang;Kim, M. Y.;K. I. Jun;J. R. Rhee;Lee, S. S.;D. G. Hwang;S. C. Yu;Lee, S. H.
    • 한국자기학회:학술대회 개요집
    • /
    • 한국자기학회 2002년도 동계연구발표회 논문개요집
    • /
    • pp.64-65
    • /
    • 2002
  • Recently the synthetic antiferromagnetic layer (SAF) has received much attention because it replaces the pinned layer of the conventional spin valve (CSV) sensors and its overall performance [1], The spin valve (SV) with SAF has the from buffer/F/Cu/APl/Ru/AP2/AF, where F is the soft ferromagnetic layer (typically NiFe with CoFe interfacial doping), AP1 and AP2 are two ferromagnetic layers (typically CoFe alloys) antiferromagnetically coupled through a thin Ru layer. (omitted)

  • PDF

6kW급 모터 드라이브 시스템을 위한 새로운 1200V SPM 개발 (Development of New 1200V SPM® Smart Power Module for up to 6kW Motor Drive Applications)

  • 박상민;이강윤;홍승현;고재성;권태성;용성일
    • 전력전자학회:학술대회논문집
    • /
    • 전력전자학회 2015년도 전력전자학술대회 논문집
    • /
    • pp.485-486
    • /
    • 2015
  • This paper introduces the new 1200V $SPM^{(R)}$ (Smart Power Module), which is fully optimized and intelligent integrated IGBT inverter modules for up to 6kW motor drive applications. It utilizes newly developed NPT trench IGBT with the advanced STEALTHTM freewheeling diode, and built-in bootstrap diode. HVICs, multi-function LVIC, and built-in thermistor provide good reliable characteristics for the entire system. This module also takes technical advantage of DBC(Direct Bonded Copper) substrate for the better thermal performance. This paper provides an overall description of the newly developed 1200V/35A $SPM^{(R)}$ 2 product.

  • PDF

철도 승강장 승객 안전을 위한 영상처리식 모니터링시스템 개발 (Development of Vision based Passenger Monitoring System for Passenger's Safety in Railway Station)

  • 오세찬;박성혁;이한민;김길동;이장무
    • 한국철도학회:학술대회논문집
    • /
    • 한국철도학회 2008년도 추계학술대회 논문집
    • /
    • pp.1354-1359
    • /
    • 2008
  • In this paper, we propose a vision based passenger monitoring system for passenger's safety in railway station. Since 2005, Korea Railroad Research Institute (KRRI) has developed a vision based monitoring system, funded by Korean government, for passenger's safety in railway station. The proposed system uses various types of sensors, such as, stereo camera, thermal-camera and infrared sensor, in order to detects danger situations in platform area. Especially, detection process of the system exploits the stereo vision algorithm to improve detection accuracy. The paper describes the overall system configuration and proposed detection algorithm, and then verifies the system performance with extensive experimental results in a real station environment.

  • PDF

공냉식 리튬 이온 배터리 팩의 열 성능 향상을 위한 내부 구조 최적화 (Internal Structure Optimization to enhance the Thermal Performance of an Air-cooled Lithium-ion Battery Pack)

  • ;조종래
    • 한국기계가공학회지
    • /
    • 제20권12호
    • /
    • pp.54-64
    • /
    • 2021
  • Electric vehicles use lithium-ion battery packs as the power supply, where the batteries are connected in series or parallel. The temperature control of each battery is essential to ensure a consistent overall temperature. This study focused on reducing ohmic heating caused by batteries to realize a uniform battery temperature. The battery spacing was optimized to improve air cooling, and the tilt angle between the batteries was varied to optimize the internal structure of the batterypack. Simulations were performed to evaluate the effects of these parameters, and the results showed that the optimal scheme effectively achieved a uniform battery temperature under a constant power discharge. These findings can contribute to future research on cooling methods for battery packs.

120MW급 열병합 복합발전시스템의 열역학적 효율 특성 (The thermodynamic efficiency characteristics of combined cogeneration system of 120MW)

  • 최명진;김홍주;김병헌
    • 한국산학기술학회논문지
    • /
    • 제18권6호
    • /
    • pp.29-36
    • /
    • 2017
  • 본 논문은 열병합 복합발전이란 하나의 프로세스에서 전기 또는 기계 동력과 열에너지의 두 형태를 생산하는 것이다. 가스터빈 열병합 발전 시스템의 각 구성부의 성능을 변수로 전체 시스템의 연료 소모와 각 구성부의 열과 전기의 성능을 표현하여야 한다. 전체시스템은 상부 시스템인 가스터빈 2대와 하부시스템인 열회수 증기발생기(HRSG) 2대, 증기터빈 1대, 지역난방열교환기 2대로 구성되어 있다. 가스터빈 열병합 복합발전시스템에서 가동시간 기준 10,000시간 후 성능시험을 각종 시험장치 설치 및 ASME PTC 46에 준한 성능시험으로 실시하였고, 발전소 전체의 종합출력과 효율에 대한 성능을 분석하였다. 이러한 성능시험 실시자료를 기초로 시험성능을 비교하여 성능변화 값을 확인하였다. 이 논문에서 가스터빈, 열회수 증기발생기, 증기터빈의 열역학적 시스템 해석을 통하여 이론적 결과 값을 산출하였다. 비교 대상은 전체 시스템의 생산열량과 대기로 배출되는 열량을 이론값과 실험값을 비교하였고, 전기출력 및 열 출력에 대한 효율을 이론값과 실제 값을 비교하였다. 가스터빈 열병합 복합발전소 성능 특성에 대한 시험결과를 열역학적 효율 특성과 비교하였으며, 0.3%의 오차를 보였다.

기후변화적응형 도시림 조성을 위한 i-Tree Canopy 기반 의사결정지원 방안 (i-Tree Canopy-based Decision Support Method for Establishing Climate Change Adaptive Urban Forests)

  • 김태한;이재영;송창길;오지은
    • 반도체디스플레이기술학회지
    • /
    • 제23권1호
    • /
    • pp.12-18
    • /
    • 2024
  • The accelerated pace of climate crisis due to continuous industrialization and greenhouse gas emissions necessitates sustainable solutions that simultaneously address mitigation and adaptation to climate change. Naturebased Solutions (NbS) have gained prominence as viable approaches, with Green Infrastructure being a representative NbS. Green Infrastructure involves securing green spaces within urban areas, providing diverse climate adaptation functions such as removal of various air pollutants, carbon sequestration, and isolation. The proliferation of Green Infrastructure is influenced by the quantification of improvement effects related to various projects. To support decision-making by assessing the climate vulnerability of Green Infrastructure, the U.S. Department of Agriculture (USDA) has developed i-Tree Tools. This study proposes a comprehensive evaluation approach for climate change adaptation types by quantifying the climate adaptation performance of urban Green Infrastructure. Using i-Tree Canopy, the analysis focuses on five urban green spaces covering more than 30 hectares, considering the tree ratio relative to the total area. The evaluation encompasses aspects of thermal environment, aquatic environment, and atmospheric environment to assess the overall eco-friendliness in terms of climate change adaptation. The results indicate that an increase in the tree ratio correlates with improved eco-friendliness in terms of thermal, aquatic, and atmospheric environments. In particular, it is necessary to prioritize consideration of the water environment sector in order to realize climate change adaptive green infrastructure, such as increasing green space in urban areas, as it has been confirmed that four out of five target sites are specialized in improving the water environment.

  • PDF

A comparative study of ultra-trace-level uranium by thermal ionization mass spectrometry with continuous heating: Static and peak-jumping modes

  • Lee, Chi-Gyu;Park, Ranhee;Park, Jinkyu;Lim, Sang Ho
    • Nuclear Engineering and Technology
    • /
    • 제52권7호
    • /
    • pp.1532-1536
    • /
    • 2020
  • For ensuring nuclear safeguards, we report the analytical signal-detection performance of thermal ionization mass spectrometry (TIMS) with continuous heating for the measurement of isotopic ratios in samples containing ultra-trace amounts of uranium. As methods for detecting uranium signals, peak-jumping mode using a single detector and static mode using multiple detectors were examined with U100 (10% 235U-enriched) uranium standard samples in the femtogram-to-picogram range. Uranium isotope ratios, n(235U)/n(238U), were measured down to levels of 1 fg and 3 fg in static and peak-jumping modes, respectively, while n(234U)/n(238U) and n(236U)/n(238U) values were measured down to levels of 100 fg in both modes. In addition, the dependency of the 238U signal intensity on sample quantity exhibited similar tendencies in both modes. The precisions of the isotope ratios obtained in the static mode over all sample ranges used in this study were overall slightly higher than those obtained in peak-jumping mode. These results indicate that isotope ratio measurements by TIMS with continuous heating are almost independent of the detection method, i.e., peak-jumping mode or static mode, which is characteristic of isotope-ratio measurements using the TIMS method with continuous heating. TIMS with continuous heating is advantageous as it exhibits the properties of multiple detectors within a single detector, and is expected to be used in various fields in addition to ensuring nuclear safeguards.