• 에너지공학
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• 제20권1호
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• pp.30-35
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• 2011

2중관형과 판형 열교환기에 에틸렌 클리콜-물 수용액으로 만들어진 아이스슬러리를 적용하는 경우의 유동 및 열적 특성을 규명하기 위하여 실험을 수행하였다. 아이스슬러리의 질량유속과 얼음 분율은 각각 800에서 3500 kg/$m^2s$과 0에서 25%이었다. 실험을 통해, 압력강하와 열전달율은 질량유속과 얼음 분율에 따라 증가하였다. 그러나 얼음 분율의 효과는 높은 질량유속 영역에서는 크지 않은 것으로 나타났다. 낮은 질량유속에서는 압력강하와 열전달율의 급속한 증가가 질량 유속에 관계되는 것으로 나타났다.

• 설비공학논문집
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• 제19권8호
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• pp.599-606
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• 2007

An experimental study was performed to measure a ice concentration of ice slurry flowing in a pipe in a real time. In the present paper, we suggested a measuring method by a refractive index and compared it to other methods by a freezing point and a density. To measure the refractive index of the solution, ice particles in the ice slurry should be completely removed and a hydro-cyclone was introduced instead of a mesh. The measuring method through the refractive index coincided with the density method using the real-time solution density within ${\pm}5%$ error range, having the error range less than the other two methods. In the other hand, the measuring method through the density has a good resolution, but the result using the initial density of the solution was different more than 10% error from that using the real-time density. And it has an error range 1.5 times greater than the method through the refractive index.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2007년도 하계학술발표대회 논문집
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• pp.188-188
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• 2007

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.1105-1110
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• 2008

An experimental study was performed to control Ice Packing Factor (IPF) of ice slurry in a pipe in a real time. This paper presented the concept that IPF can be adjusted by the amount of the solution contained to ice slurry. Based on this concept, we designed IPF controller consisting of the outlet tube providing ice slurry and the upper tube discharging only a solution through holes, and investigated the technical validity and efficiency of the controller experimentally. As a result, the original proposed IPF controller could not control IPF of ice slurry in a pipe. This is because an ice of ice slurry was drained out into not only the outlet but also the upper of the controller due to the size of the holes relatively large compared to the ice particle. Therefore, we changed the hole size of IPF controller surface using fine meshes and then, observed that IPF in a pipe was increased by $4{\sim}7$ percent when the hole size was $80{\mu}m$ and less.

• 설비공학논문집
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• 제14권5호
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• pp.385-390
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• 2002

To clarify the hydraulic characteristics of ice slurry which made from 6.5% ethylene glycol-water solution flowing through circular pipes of small diameter, experimental studies were performed. The flow pattern was observed and the pressure drop was measured in acrylic pipes with inner diameter of 24 mm. The results of flow visualization revealed that ice particles flowed along the top of pipes in the ranges of small ice fraction and low flow rate, while Ice particles diffused into the whole region of pipes flowed like a homogeneous flow for high flow rate and high ice fraction. An increase in frictional pressure drop was measured as the ice fraction increased in all pipes and unstable flow was observed for up-ward vertical pipe.

• 설비공학논문집
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• 제14권5호
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• pp.391-397
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• 2002

Pressure drop were experimentally investigated for ice slurry flowing in the acrylic pipes with inner diameter of 24 mm. Ice slurry was made from 6.5% ethylene glycol-water solution, and the pipes is consisted of horizontal, vertical (upward and downward) and $90^{\circ}$ elbow pipe. The ice Packing factor (IPF) and the flow rate of the experiments were varied from 0 to 30% and from 5 to 70kg/min respectively The measured pressure drop in various pipe positions were compared with those for the solution flow (IPF=0). The pressure drop was larder than that for solution flows as the IPF increased when the flow rate was low or very high. Sharp increases in pressure drop were observed for the cases when IPF is more than 70% in horizontal and vertical pipes, whereas the pressure drop increased with the IPF simultaneously in an elbow pipe.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2006년도 하계학술발표대회 논문집
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• pp.233-238
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• 2006

A new district cooling system using ice slurry for the uncertain cooling load of the future is presented. The chilled water produced by the absorption chillers is used for the base cooling load. The temperature of the chilled water is reduced by mixing of ice slurry depending on increasing of the cooling load. Finally, IPF of the ice slurry is increased up to 10% at the peak load. The transporting mass flow rate is decreased down to 44.7%, and the diameter of the main pipe is decreased down to 66.7%, but the diameter of the branched pipe is designed as the same size of the chilled water.

• 설비공학논문집
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• 제19권8호
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• pp.593-598
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• 2007

The present study has dealt with the measuring method of ice slurry viscosity using falling sphere viscometer. The experimental apparatus was composed by test section and high-speed video system. And the spheres used in this study were alumina and glass. The main parameters were ice packing factor (IPF) and falling velocity of sphere so the acquired results were discussed for these parameters. The viscosity of ice slurry was calculated by using measured falling velocity and moving distance at instantaneous time and the Stokes hypothesis was used for this calculation. It was clarified that possible measuring range was $IPF\;=\;0.06{\sim}0.14$ of this type of measuring device and measuring method. In addition, it was clarified that the viscosity of ice slurry increased to increase of ice packing factor (IPF) of ice slurry.

• 한국수산과학회지
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• 제15권2호
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• pp.154-160
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• 1982

1) 수-단백질-지질의 3성분계 식품으로서 '두부'를 선택하여 일차원 비정상 열전도에 관한 실험을 행하였다. 두부는 불균질계 물질이지란 '유효'한 개념을 도입하여 유효열확산율을 측정함으로써 수학적으로 균질계 물질로 취급이 가능했다. 2) 저자가 고안 제작한 장치의 성능(performance)및 정도를 검토하기 위하여 표준물질로서 toluene은 물론 얼음(빙)의 열확산율을 측정한 결과, $-5\sim-25^{\circ}C$의 온도역에서 문헌치와 비교하여 재현성 $\pm1.5\%$, 오차 $-2\%$ 정도로 그 신뢰도는 매우 높았다. 3) 경계조건이 경시적으로 변화하는 경우라 찰지라도 Crank-Nicolson's implicit method를 이용하여 열확산율을 구할 수 있는 computer program을 개발했다. 4) 성분조성이 각각 상이한 3종류의 두부의 열확산율을 측정한 결과, 그 양들은 수분, 단백질 및 지질의 각 성분 함량의 분율에 정확하게 의존하고 있음을 보여 주었다.

• 설비공학논문집
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• 제20권12호
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• pp.825-832
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• 2008

The ice slurry maker which can produce the ice slurry well for the ice particle in-flowing condition was revised. We removed the stagnant region at the top of the ice slurry maker, and IPF 40% could be realized. The IPF controller with 6 mm diameter holes at the bottom was designed. But the IPF controller with only 6 mm diameter holes could not control IPF in a pipe. This is because the ice particles at ice slurry flow exist homogeneously not only at the upper part but also at the bottom part. We changed the hole size of IPF controller surface using fine meshes and then, IPF in a pipe was increased by 70% when the hole size was $80{\mu}m$ and less.