• Title/Summary/Keyword: Flux mapping

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Estimating the urban radiation heat flux distribution and the reduction effect of building and tree shade (건물과 수목의 그림자에 의한 도시의 열 분포 산정 및 저감효과 연구)

  • Park, Chae-Yeon;Lee, Dong-Kun;Yoon, June-Ha
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.21 no.6
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    • pp.1-13
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    • 2018
  • Mapping radiation heat flux of urban area is essential for urban design and landscape planning. Because controlling urban geometry and generating green space are important urban design strategies for reducing urban heat, urban planner and designer need to recognize the micro urban heat distribution for adequate urban planning. This study suggests a new methodology for mapping urban radiation heat flux in a micro scale considering buildings and trees' shade. For doing that, firstly, we calculate net radiation for each urban surfaces (building, road (not shaded, building shaded, tree shaded), ground (not shaded, building shaded, tree shaded), tree (not shaded, building shaded)). Then, by multiplying the area ratio of surfaces to the net radiation, we can obtain the radiation heat flux in micro-scale. The estimated net radiation results were found to be robust with a $R^2$ of 90%, which indicates a strong explanatory power of the model. The radiation heat flux map for 12h $17^{th}$ August explains that areas under the building and tree have lower net radiation heat flux, indicating that shading is a good strategy for reducing incident radiation. This method can be used for developing thermal friendly urban plan.

PMCR-A Power Mapping and Calibration Routing for 600 MWe CANDU-PHW Reactors

  • Oh, Se-Ki;G.Kugler
    • Nuclear Engineering and Technology
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    • v.11 no.4
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    • pp.275-286
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    • 1979
  • In 600 MWe CANDU-PHW reactors PMCR will be used on-site for calibration of the regional overpower system. PMCR will be executed off-line in one of the station computers. The program calculates accurate channel power maps by incorporating a fuel turnup dependent flux to power conversion algorithm. Fuel turnup is calculated by PMCR, hence it is independent of other software. Extensive comparisons with the uniform flux/power conversion approximations were made. Significant improvements in power mapping accuracy are achieved with PMCR.

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Indirect Detection of Rotor Position of Switched Reluctance Motor Based on Flux Linkage Analytic Model

  • Zhou, Yongqin;Hu, Bo;Wang, Hang;Jin, Ningzhi;Zhou, Meilan
    • Journal of Electrical Engineering and Technology
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    • v.13 no.2
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    • pp.829-837
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    • 2018
  • In this paper, a flux linkage model based on four magnetization curves fitting is proposed for three-phase 12/8 switched reluctance motor (SRM), with the analysis of the basic principle of flux detection method and function analysis method. In the model, the single value function mapping relationship between position angle and flux is established, which can achieve a direct estimation of rotor position. The realization scheme of SRM indirect position detection system is presented. It is proved by simulation and experiment that the proposed scheme is suitable for rotor position detection of SRM, and has high accuracy of position estimation.

Flux Density Distribution of the Dish Solar Concentrator (KIERDISH II) (KIERDISH II 태양열 집광시스템의 플럭스밀도 분포)

  • Kang, Myeong-Cheol;Kang, Yong-Heack;Yoo, Seong-Yeon
    • Journal of the Korean Solar Energy Society
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    • v.24 no.4
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    • pp.11-18
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    • 2004
  • A solar concentrator, named KIERDISH II, was built at KIER in order to investigate the feasibility of high temperature solar energy application system. The constructed concentrator is a dish type solar concentrator with a focal length of 4.68m and a diameter of 7.9m. To successfully operate KIERDISH II, optimal design of the absorber is very important and flux density distribution has to be known. The focal flux density distribution on the receiver was measured. We have observed the shape and size of flux images and evaluated percent power within radius. Flux density distribution is usually measured by a CCD(charge coupled device) camera and a radiometer. In this paper we present a flux mapping method to estimate the characteristic features of the flux density distribution in the focal region of solar concentrator. The minimum radius of receiver is found to be 0.15m and approximately 90% of the incident radiation is intercepted by receiver aperture.

Characteristic of the Radiation Heat Flux Distribution for the KIER Solar Furnace (KIER 태양로의 열유속 분포 특성)

  • Chai, Kwan-Kyo;Lee, Hyun-Jin;Kim, Jong-Kyu;Yoon, Hwan-Ki;Lee, Sang-Nam;Kang, Yong-Heack;Seo, Tae-Beom
    • 한국태양에너지학회:학술대회논문집
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    • 2011.11a
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    • pp.74-79
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    • 2011
  • Concentration characteristics of the KIER solar furnace are analyzed with a heat flux measurement technique. Total heat capacity of 40kW was confirmed within 1.04% average error, and the normalized maximum heat flux of 3,452 $kW/m^2$ was proved. Non-Gaussian flux distribution in the vertical direction implies that reflectors should not be random rather inclined downwards. Moreover, we characterized flux distribution variations with furnace blind opening ratio, distance from the focal plane, and misalignment of the measurement system. Based on the results, the heat flux distribution can be simply estimated once reflectivity and direct normal insolation values are known. This study will be helpful to the design and the performance evaluation of receivers or chemical reactors.

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