• Title/Summary/Keyword: 휜 효율

Search Result 22, Processing Time 0.023 seconds

A Study on the Fin Efficiency of Continuous Fin with Combined Heat and Mass Transfer (열과 물질 전달을 수반하는 연속휜의 휜효율에 관한 연구)

  • 정세환
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.22 no.4
    • /
    • pp.445-450
    • /
    • 1998
  • In the present paper the effects of combined heat and mass transfer on the fin efficiency were calculated. Sector method was used for calculating the fin efficiency of the continuous fin. The parameter Lewis No. and C which describe the combined heat and mass transfer is derived by using the heat and mass transfer analogy and effects of Lewis No. and C on the fin efficiencies were calculated.

  • PDF

A Study on the fin efficiency of continuous fin - tube heat exchanger, -In the case of sensible heat transfer- (섹터법을 이용한 연속휜-튜브형 열교환기의 휜효율에 관한 연구, -현열 열전달의 경우-)

  • Jung, Hyeong-Ho
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.20 no.5
    • /
    • pp.76-81
    • /
    • 1996
  • In this paper, a calculation method for fin efficiency of continuous fin is introduced. The continuous fin of in-line and staggered arrangement was divided into many sectors and fin efficiencies of each sectors were calculated by assuming that each sectors be the circular fins. To get the converged fin efficiency which is averaged by the each areas, the number of sectors was increased. The results were compared with equivalnet method by varying the aspect ratios in both cases of in-line and staggered tube arrangement and showed some differences of fin efficiencies.

  • PDF

VERIFICATION OF FIN EFFICIENCY THEORY FOR THE CIRCULAR FINNED-TUBE HEAT EXCHANGER BY NUMERICAL EXPERIMENT (원형휜-원형관 열교환기의 휜효율 이론에 관한 수치적 검증)

  • Kang, H.C.;Lim, B.B.;Lee, J.W.;Chang, B.C.;Ahn, S.W.
    • 한국전산유체공학회:학술대회논문집
    • /
    • 2008.03a
    • /
    • pp.137-142
    • /
    • 2008
  • The purpose of the present study is to investigate the convective heat transfer characteristics and the validity of fin efficiency of the circular finned-tube heat exchanger by using commercial CFD code. The heat transfer coefficient obtained by using the laminar model was 22% overestimated to the experimental data. The fin surface temperature compared with the experimental data measured by the liquid crystal method. The fin efficiency by the present numerical experiment, defined as normalized and averaged fin surface temperature, was greater than the theoretical fin efficiency and the difference is increased at high value of the factor m.

  • PDF

VERIFICATION OF FIN EFFICIENCY THEORY FOR THE CIRCULAR FINNED-TUBE HEAT EXCHANGER BY NUMERICAL EXPERIMENT (원형휜-원형관 열교환기의 휜효율 이론에 관한 수치적 검증)

  • Kang, H.C.;Lim, B.B.;Lee, J.H.
    • Journal of computational fluids engineering
    • /
    • v.14 no.4
    • /
    • pp.7-12
    • /
    • 2009
  • The purpose of the present study is to investigate the convective heat transfer characteristics and the validity of fin efficiency of the circular finned-tube heat exchanger by using commercial CFD code. The heat transfer coefficient obtained by using the laminar model was 22% overestimated to the experimental data. The fin surface temperature compared with the experimental data measured by the liquid crystal method. The fin efficiency by the present numerical experiment, defined as normalized and averaged fin surface temperature, was greater than the theoretical fin efficiency and the difference is increased at high value of the factor $mr{\phi}$.

Heat Transfer Characteristics of a Circular Fin-tube Heat Exchanger (원형휜-원형관의 열전달 특성)

  • 강희찬;조동영;강민철
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.15 no.9
    • /
    • pp.762-767
    • /
    • 2003
  • An experimental study was conducted to investigate the heat transfer characteristics of a circular finned-tube heat exchanger. The nineteen cases of configuration varying fin material, fin outer diameter and fin pitch were tested by means of the experiment and the numerical calculation. The measured heat transfer data for the circular finned-tube heat exchanger were provided. A transition of heat transfer was found in the case of low fin pitch. The thermal conductivity of fin affected on the pure heat transfer coefficient.

CONVECTIVE HEAT TRANSFER CHARACTERISTICS OF OVAL FIN-CIRCULAR TUBE HEAT EXCHANGER (타원형휜-원형관 열교환기의 강제대류 열전달 특성)

  • Kang, H.C.;Lee, J.H.
    • 한국전산유체공학회:학술대회논문집
    • /
    • 2009.04a
    • /
    • pp.341-346
    • /
    • 2009
  • The purpose of the present study is to investigate the flow resistance and the heat transfer characteristics of oval fin-tube heat exchanger. Six kinds of oval fin having the same fin area and the different diameter ratio tested numerically. Test data for the heat transfer, pressure drop and fin temperature were shown and discussed. The pressure drop and heat transfer increased for increasing the oval fin diameter ratio(diameter of span-wise direction to diameter of longitudinal diameter) up to 50% and 45% respectively.

  • PDF

Air Side Heat Transfer Charactieristics of Tension Wound Transverse Fin with Minichannel (장력 감김으로 부착된 가로방향 휜-미니채널의 공기측 열전달 특성)

  • Kim Jong-Soo;Im Yong-Bin
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.29 no.6
    • /
    • pp.701-706
    • /
    • 2005
  • Pipes, tubes. and tubular sections with external transverse high fins have been used extensively for heating cooling, and degumidifying air and other gases. This work was performed to investigate an air side heat transfer charactieristics of minichannel with tension wound transverse fin. This estimate was confirmed conversion heat capacity the air side surface area enlargement and heat transfer charactieristics performed available inlet tube side hot water mass flux or outlet tube side air frontal air velocity. The most suitable tension wound transverse finned minichannel was measured extremely low in air side pressure drop and fin effectiveness $3.3\~4.4$. The pressure drop $0.9\~2.8Pa$ was ranged frontal air velocity $0.5\~1.2m/s$. It is also appeared that heat transfer in air side could be better conversion heat area which has been increased $330\%$ of heat capacity compared with the bare tube.

Performance Analysis of the Rectangular Fin (사각 휜에 대한 성능해석)

  • Gang, Hyeong-Seok;Yun, Se-Chang;Lee, Seong-Ju
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.25 no.1
    • /
    • pp.1-8
    • /
    • 2001
  • Performance of a rectangular fin is investigated by a three dimensional analytical method. Heat loss and the temperature obtained from the three dimensional analysis are compared with those calculated from a two dimensional analysis. Fin effectiveness, fin resistance and fin efficiency for the rectangular fin are presented as a function of non-dimensional fin length and fin width. The results are obtained in the following : (1) heat loss calculated from the two dimensional analysis is the same as that obtained from the three dimensional analysis with adiabatic boundary condition in z-direction, (2) heat loss obtained from the two dimensional analysis approaches the value for the three dimensional analysis as the non-dimensional fin width becomes large, (3) fin effectiveness increases as non-dimensional fin length increases and non-dimensional fin width decreases, and vice versa for fin efficiency.

Performance Analysis of a Thermally Asymmetric Triangular Fin (열적 비대칭 삼각 휜의 성능해석)

  • Gang, Hyeong-Seok
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.26 no.1
    • /
    • pp.66-73
    • /
    • 2002
  • Fin effectiveness and efficiency of a thermally asymmetric triangular fin are represented as a function of the ratio of fin lower surface Biot number to upper surface Biot number and the non-dimensional fin length. For this analysis, two dimensional separation of variables method is used. When fin effectiveness is 2 and efficiency is 90%, the relationship between the non-dimensional fin length and the ratio of fin lower stir(ace Biot number to upper surface Biot number is shown. The relationship between the non-dimensional fin length and the upper surface Biot number for the same condition is also presented.