• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2006년도 하계학술발표대회 논문집
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• pp.1199-1204
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• 2006

The pressure drop and heat transfer coefficient were measured at room temperature in CFB heat exchanger with multiple vertical tubes. Also the circulation rate of solid particles was measured. The theoretical model for predicting heat transfer coefficient using the solid flowrate was developed in this study. The model predictions were compared with the measured heat transfer coefficient to show relatively good agreement.

• Journal of Mechanical Science and Technology
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• 제16권9호
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• pp.1175-1182
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• 2002

The commercial viability of heat exchanger is mainly dependent on its long-term fouling characteristic because the fouling increases the pressure loss and degrades the thermal performance of a heat exchanger. An experimental study was performed to investigate the characteristics of fluid flow and heat transfer in a fluidized bed heat exchanger with circulating various solid particles. The present work showed that the higher densities of particles had higher drag force coefficients, and the increases in heat transfer were in the order of sand, copper, steel, aluminum, and glass below Reynolds number of 5,000.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2006년도 하계학술발표대회 논문집
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• pp.1101-1106
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• 2006

The water fluidized bed heat exchanger was installed to recover heat from paper mill hood exhaust air containing lot of moisture and also fouling contaminants. The hood exhaust air flow rate was about $110,000m^3/hr$ at $70^{\circ}C$. The commercial scale field test apparatus has been operated for 3 months. As a result of operation, total heat recovered was 2,380,000 kcal/hr and proportion of the latent heat to total heat was 74%. The annual energy saving was estimated as 450 million won.

• 설비공학논문집
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• 제3권3호
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• pp.168-175
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• 1991

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.

• Journal of Advanced Marine Engineering and Technology
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• 제25권6호
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• pp.1291-1297
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• 2001

The commercial viability of heat exchanger is mainly dependent on their long-term fouling characteristics because the feeling increases the pressure loss and degrades the thermal performance of a heat exchanger An experimental study was performed to investigate the characteristics of fluid flow in a fluidized bed heat exchanger with circulating various solid particles. The present work showed that the drag force coefficients of particles in the internal flow were higher than in the external flow, in addition, they were lower with the shapes of particles being closer to the spherical geometries.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집B
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• pp.705-710
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• 2001

The commercial viability of heat exchanger is mainly dependent on their long-term fouling characteristics because the fouling increases the pressure loss and degrades the thermal performance of a heat exchanger. An experimental study was performed to investigate the characteristics of fluid flow in a fluidized bed heat exchanger with circulating various solid particles. The present work showed that the drag force coefficients of particles in the internal flow were higher than in the external flow, in addition, they were lower with the shapes of particles being closer to the spherical geometries.

• 대한기계학회논문집B
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• 제25권12호
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• pp.1776-1783
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• 2001

Heat recovery from boiler exhaust gas with multi-stage water-fluidized-bed heat exchanger is analyzed in this study. The recovered energy here is not only sensible heat but also latent heat contained in the exhaust gas. In this system direct contact heat transfer occurs while exhaust gas passes through water bed and the thermal energy recovered this way is again delivered to the water circulating through heat exchanging pipes within the bed. Thus the thermal energy of exhaust gas can be recovered as a clean hot water. A computer program developed in this study can predict the heat transfer performance of the system. The results of experiments performed in this study agree well with the calculated ones. The heat and mass transfer coefficients can be fecund through these experiments. The performance increases as the number of stage increases. However at large number of stages the increasing rate becomes very low.

• International Journal of Air-Conditioning and Refrigeration
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• 제12권4호
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• pp.198-205
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• 2004

An experimental study was carried on the characteristics of fluid flow and heat transfer in a fluidized bed shell-and-tube type heat exchanger with corrugated tubes. Seven different solid particles having same volume were circulated in the tubes. The effects of vari­ous parameters such as water flow rates, particle geometries and materials, and geometries of corrugated tubes on relative velocities and drag coefficients were investigated. The present work showed that the drag force coefficients of particles in the corrugated tubes were usually lower than those in the smooth tubes, meanwhile the relative velocities between particles and water in the corrugated tubes were little higher than those in the smooth tubes except the particles of glasses.

• 설비공학논문집
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• 제15권5호
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• pp.406-412
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• 2003

An experimental study was carried on the characteristics of fluid flow and heat transfer in a fluidized bed shell-and-tube type heat exchanger with corrugated tubes. Seven different solid particles having same volume were circulated in the tubes. The effects of various parameters such as water flow rates, particle geometries and materials, and geometries of corrugated tubes on relative velocities and drag coefficients were investigated. The present work showed that the drag force coefficients of particles in the corrugated tubes were usually lower than those in the smooth tubes, meanwhile the relative velocities between particles and water in the corrugated tubes were little higher than those in the smooth tubes except the glass.

• 태양에너지
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• 제14권2호
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• pp.39-50
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• 1994

알루미나 입자(${\rho}_p=2298kg/m^2$)를 유동입자로 사용한 수직이중관식 유동층형 열교환기에서 입자직경($d_p$=0.41, 0.54, 0.65, 0.77mm) 및 초기충진높이($H_o$=50, 100, 150, 200, 250mm)가 전열성능에 미치는 영향을 소요동력의 관점에서 고찰하였다. 내관으로 핀이 달린 관을 사용하는 경우와 평활관을 사용하는 경우의 전열성능을 단상강제대류 열교환기와 비교 검토하였다. 소요동력에 따른 전열성능을 비교한 결과, 입자직경이 작을 수록, 초기충진높이가 높을 수록 전열효과가 증가하며, 실험범위에서 핀이 달린 관을 사용하는 경우가 평활관을 사용하는 경우보다 초기충진 높이에 따라 $2.96{\sim}3.45$배의 전열촉진효과가 있음을 알았다. 또 단상강제대류형 열교환기에 비해 유동층형 열교환기가 열전달효과가 우수한 영역이 존재하며, 평활관을 사용하는 경우에는 최대 91.3%, 핀이 달린 관을 사용하는 경우에는 최대 127.1% 의 전열촉진효과가 있었다.