http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
양한주,서정윤,Yang, H.J.,Seo, J.Y. 대한설비공학회 1990 설비공학 논문집 Vol.2 No.3
In this study, heat transfer characteristics of vertical fixed bed with air flowing through were experimentally investigated. The experiments were conducted for cases where heat was transfer steady state conditions from an immersed cylindrical heated to the surrounding fixed ved of steel balls. Based on the experimental data, the optimum conditions for heat transfer augmentation have been determined and shows in empirical forms. For the same power loss, comparison of heat transfer effect between the fixed bed and single phase forced convection device indicates that both miniaturization of heat exchange device and heat transfer augmentation at low flow velocity are possible by application of the fixed bed to heat exchangers. The present results could provide a useful design information for the heat exchangers where fixed beds are used.
신현준(H. J. Shin),양한주(H. J. Yang),오수철(S. C. Ohu) 한국자동차공학회 1982 오토저널 Vol.4 No.3
Heat transfer on packed bed is considered to be important for the effective designs of chemical reaction equipment, air conditioning system, and storage type heat exchanger, etc. Currently studies are being carried out quite actively in this field in order to increase the heat transfer effeciency.<br/> The effect of heat transfer is closely related to materials, shapes, porosities and packing states of packed bed as well as mutual dimensional relations between particles and the container. Investigation shows that heat transfer results appear to be influenced by such parameters as fluid velocity through packed bed, mass flow, and thermal properties. It is noted that viscosity is also considered to be an important factor in this problem.<br/> In this study, effective thermal conductivities on packed bed, effects of thermal conductivity (Ke) and friciton factor (Fk) according to change of porosity ( ε) and Reynolds number (Reh), and pressure loss of the fluid, are experimentally investigated.<br/> Results show that the effective thennal conductivity increases and the friction factor decreases, as against the increase of Reynolds number. But as the increase of porosity increase them both.
입자층(粒子層)을 이용한 열교환기(熱交換器)에서 소요동력(所要動力)에 따른 전열특성(傳熱特性)에 관(關)한 연구(硏究)
유지오,양한주,조용철,서정윤,Yoo, J.O.,Yang, H.J.,Cho, Y.C.,Seo, J.Y. 대한설비공학회 1992 설비공학 논문집 Vol.4 No.4
In order to improve the performance of heat exchanger, fluidized bed is often employed. The experiments are carried out in fluidized double pipe parallel flow heat exchanger in which finned tube is vertically immersed. And the heat transfer coefficients between the heated tube and fluidized bed of alumina beads(dp=0.41, 0.54, 0.65, 0.77mm) are calculated as a function of air fluidized velocity and pumping power. The effects of particle size, static bed height and pumping power on the heat transfer coefficients are investigated. And the heat transfer coefficients are compared with that of single phase forced convection heat exchanger. In particular, the heat transfer performance of each type heat exchanger is evaluated in relation to the pumping power.
이종수,양한주,최국광,서정윤,Lee J.S,Yang H.J,Choi K.K,Seo J.Y 대한설비공학회 1987 설비저널 Vol.16 No.1
In this paper, the local effective thermal conductivities and calculated by using the actual temperature distribution in packed bed. The variations of these are investigated for radius and air stream direction, flow rate and particle diameter. The resulting local effective thermal conductivi-ties are classified in the inner zone of bed and vicinity zone of the wall surface. Also these are related to dimensionless axial direction position, radius direction position, and particle diameter and Reynolds number which uses particle diameter as the characteristic length. If these correla-tions are represented by function, the equation is showed in Eq. (3-4). This equation is well satisfied with experimental results within $\pm25\%.$
김광철,류지오,양한주,서정윤,Kim, G.C.,Yoo, J.O.,Yang, H.J.,Seo, J.Y. 대한설비공학회 1990 설비공학 논문집 Vol.2 No.2
Air-solid bed has been known to be an effective heat transfer augmentation device which could be applied to heat exchangers. In this study, pressure drop and heat transfer characteristics of vertical annular fluidized bed heat exchanger with air flowing through were studied experimentally. The experiments was conducted to calculate overall heat transfer coefficient on fluidized bed heat exchangers immersed single vertical tube and investigate minimum fluidized velocity in fluidized bed of alumina beads and steel balls. The influence of flow direction, particle diameter, the heights of static bed and air mass fluidizing velocity has been examined. The experimental results showed the optimum operating condition and effective static bed height for fluidized bed heat exchangers. For the same power loss, comparisions of heat transfer effect between the fluidized bed heat exchanger and the single phase forced convetion heat exchanger indicate that both miniaturization of heat exchanger and heat transfer augmentation at low flow velocity are possible by application of the air-solid to heat exchangers.
임종규,류지오,양한주,서정윤,Lim, J.G.,Yoo, J.O.,Yang, H.J.,Seo, J.Y. 대한설비공학회 1990 설비공학 논문집 Vol.2 No.2
In this study, the overall heat transfer coefficients are calculated on fluidized bed double pipe heat exchanger and single phase double pipe heat exchanger at the same condition. The effect of the particle size, its material, fluidizing velocity and static bed height on overall heat transfer coefficient has been investigated. The main conclusions obtained from the experiment are as follows. 1. The overall heat transfer coefficient of the fluidized bed heat exchanger is higher than that of single phase forced convective heat exchanger (maximum 2.3 times) 2. The value of the overall heat transfer coefficient increase with an increase in static bed height and decrease with an increase in particle size. 3. For the same particle size, the particle of low density can obtain higher overall heat transfer coefficient than that of high density.
유동층형(流動層形) 핀관(管) 열교환기(熱交換器)의 열전달특성(熱傳達特性)에 관(關)한 기초적(基礎的) 연구(硏究)
이석우,유지오,양한주,서정윤,Lee, S.W.,Yoo, J.O.,Yang, H.J.,Seo, J.Y. 대한설비공학회 1991 설비공학 논문집 Vol.3 No.3
Experiments have been conducted to measure the overall heat transfer coefficient for gas-solid fluidized double pipe heat exchanger with finned tube. The average particle diameters of alumina are used in 0.4, 0.5, 0.6 and 0.9mm. And the effects of average particle diameter, static bed height and flow velocity on overall heat transfer coefficient have been investigated. Also the heat transfer effect of fluidized bed was compared with that of single phase forced convection and that of heat exchanger with smooth tube.