• 제목/요약/키워드: D-Tube

검색결과 1,301건 처리시간 0.032초

ON A GENERALIZATION OF FENCHEL`S THEOREM

  • Chai, Y.D.;Kim, Moon-Jeong
    • 대한수학회논문집
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    • 제15권1호
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    • pp.103-109
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    • 2000
  • In this paper, we present the proof of generalized Fenchel's theorem by estimating the Gauss-Kronecker curvature of the tube of a nondegenerate closed curve in R$^{n}$ .

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초임계압 보일러 수냉벽 튜브의 파열사고 분석 (Failure Analysis of Waterwall Tubes in Super Critical Boiler)

  • 김범수;정남근;김두수;이성호
    • 동력기계공학회지
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    • 제7권1호
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    • pp.20-24
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    • 2003
  • Boiler is one of the most important utilities providing steam to turbine in order to supply mechanical energy in thermal power plant. It is composed of thousands of tubes for high efficient heat transfer. Water is converted to steam inside the waterwall tubes. Many chemical components dissolved in boiler water come out of itself, deposit to the tube wall surface, prohibit heat transer, raise tube metal temperature, eventually fail the boiler tubes. Several tasks such as fracture surface study, tensile test, hardness test, metallurgical test, composition analysis of sticking elements were conducted to identify the root cause of tube failure.

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Shell & Tube 열교환기 Shell 측 열전달 및 유동에 대한 수치해석 (NUMERICAL ANALYSIS ON THE HEAT TRANSFER AND FLOW IN THE SHELL AND TUBE HEAT EXCHANGER)

  • 이상혁;이명성;허남건
    • 한국전산유체공학회지
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    • 제12권3호
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    • pp.13-19
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    • 2007
  • A numerical simulation on the heat transfer and flow field was carried out to improve the performance of the shell and tube heat exchanger. The steady incompressible 3-D Navier-Stokes solution is obtained with the actual operational condition and geometry of the heat exchanger. Based on this study, it is noted that the present geometry of the heat exchanger causes poor heat transfer since the air inside shell does not flow through the tube bundle, but around it. The enhancement of the heat transfer can be achieved by the variation of the design factor like the sealing strip located on the top/bottom and middle of the baffle, but it causes the increasement of the pressure drop. In this paper, the effects of the location and size of the sealing strips and flow rate through the heat exchanger on the heat transfer and pressure drop are studied.