• 에너지공학
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• 제9권3호
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• pp.261-268
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• 2000

A heat transfer correlation to predict the vaporization of a water droplet in highly superheated steam during a loss-of-coolant accident(LOCA) of a nuclear power plant is provided. Vaporization of liquid fuel or water droplets in superheated air or steam and subsequent interface heat transfer between a liquid droplet and superheated gas is typically correlated by way of a Nusselt number as a function of Reynolds number, Prantl number, and in some cases including mass transfer number. Presently available correlations and experimental data of the evaporation of liquid droplets in air or steam are analyzed and a new Nusselt number correlation is proposed taking Schmidt number into consideration in order to account for binary diffusion of the vapor as well, Nu$\_$f/(1+B)$\^$0.7/=2+0.53Sc$\_$f/$\^$-1/5/Re$\_$M/$\^$$\sfrac{1}{2}$/Pr$\_$f/$\^$$\sfrac{1}{3}$/ for which properties are evaluated at film condition except the density of Reynolds number evaluated at ambient condition. Diverse correlations for various combinations of liquid and gas species are put into single equation. The blowing correction factor of (1+B)$\^$0.7/ is confirmed appropriate, and a criterion to distinguish so-called high- and low-temperature condition of ambient gas is set forth.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 추계학술대회논문집
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• pp.565-569
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• 2004

Conventional methods for reducing vibration in engineering designs (i.e. by stiffening or detuning) may be undesirable or inadequate in conditions where size or weight must be minimized or where complex vibration spectra exist. Alloys which combine high damping capacity with good mechanical properties can provide attractive technical and economic solutions to problems involving seismic, shock and vibration isolation. To meet these trends, we have developed a new high damping Fe-17%Mn alloys. Also, the alloy has advantages of good mechanical properties and more economical than any other known damping alloys(1/4 times as cost of non-ferrous damping alloy). Thus, the high damping Fe-17%6Mn alloy can be widely applied to household appliances, automobiles, industrial facilities and power plant components with its excellent damping capacity(SDC, 30%) and mechanical property(T.S 700MPa). It is the purpose of this paper to introduce the characterization of the high damping Fe-17%Mn alloy and the results of retrofit several such applications.

• 한국세라믹학회지
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• 제39권8호
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• pp.735-741
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• 2002

미분탄 화력발전소에서 보일러의 부하를 변화시켰을 때 전기집진기에서 단별 채취한 fly ash에 대해서 디지털 이미지 분석을 이용하여 원형지수를 검토하였다. 원형지수 측정은 다음과 같은 다섯 단계, 즉 ① 이미지 획득, ② 이미지 전처리, ③ 검출, ④ 이미지 후처리, ⑤ 측정의 단계를 거쳐 이루어 졌다. Fly ash의 평균 원형지수는 0.78∼0.83의 범위를 나타냈으며, 같은 위치에 있는 호파에서 채취한 fly ash는 보일러의 부하에 관계없이 유사한 원형지수 값을 나타냈다. 그리고 첫 번째 호파에서 세 번째 호파로 갈수록, 즉 fly ash의 평균 입경이 작아질수록 원형지수는 증가하는 경향을 나타냈다.