Study of Direct Contact Heat Transfer Characteristics from a Liquid Ice
Grant-in-Aid for General Scientific Research (B)
|Allocation Type||Single-year Grants|
|Research Institution||Hokkaido University|
FUKUSAKO Shoichiro Hokkaido Univ.Fac.of Eng., Professor, 工学部, 教授 (00001785)
HORIBE Akihiko Hokkaido Univ.Fac.of Eng., Instructor, 工学部, 助手 (50229241)
YAMADA Masahiko Hokkaido Univ.Fac.of Eng., Assoc.Professor, 工学部, 助教授 (70230480)
田子 真 北海道大学, 工学部, 助手 (50171682)
|Project Period (FY)
1992 – 1994
Completed(Fiscal Year 1994)
|Budget Amount *help
¥8,000,000 (Direct Cost : ¥8,000,000)
Fiscal Year 1994 : ¥1,000,000 (Direct Cost : ¥1,000,000)
Fiscal Year 1993 : ¥1,900,000 (Direct Cost : ¥1,900,000)
Fiscal Year 1992 : ¥5,100,000 (Direct Cost : ¥5,100,000)
|Keywords||Liquid Ice / Heat Removal / Cold Heat Storage / Cold Heat Transport / Melting Heat Transfer / Forced Convection / Saving of Environment / Normalizing of Electricity / 蓄冷熱 / PCM|
An experimental study has been performed to investigate the direct contact heat transfer characteristics between air and liquid ice. The effects of concentration of solution, inlet-air temperature, height of liquid-ice bed, and the flow rate of inle-air on the heat-removal performances were extensively examined. The results revealed that the flow rate of inlet-air exertes considerable effects on the direct contact heat transfer characteristics, and that there might be an optimum condition of the flow rate of air for total removed heat. The average heat removal rate was favorably correlated by the flow rate of inlt-air and the temperature difference between inlet-air and equilibrium freezing temperature of initial concentration of solution.
The experimental apparatus fundamentally consists of test section, cooling-brine circulating loop, and air cooling system. The fluidization air for the three-phase fluidized bed was utilized as the medium of direct contact heat transfer. Air was coole
d and dehuminided in the air chamber in advance. After both the flow rate and the temperature of air and humidity were favorably controlled, it was introduced to the test section. The test section consists of a test bessel, a distributor, and the calming section. The test vessel is made of transparent lucite tube which has dimensions of 150 mm in inner diameter and 330 mm in length. In order to obtain the uniform air flow at the inlet of test section, stainless mesh (20 mesh) and the Nylon cloth (200 mesh) along with the distributor were utilized at the inlet of the tube.
The testing liquid ice was made up by mixing the fine ice particles and ethylene-glycol solution whose temperature and concentration were set in prescribed value. Ice packing factor was set constant at 62%. The initial height of the testing liquid ice h_b was set at 170 mm throu the experiments.
Experiments were carried out to study the direct contact heat transfer characteristics of the solid-air-liquid three-phase fluidized liquid ice-bed. The following conclusions may be drawn within the parameters covered in the present study.
(1) The heat removal rate is affected by the flow rate of inlet-air mostly and the temperature of inlet-air and initial concentration of solution, while it is little affected by the height of the liquid ice bed.
(2) The total removed heat decreases as the flow rate of air increases owing to mainly the heat generation by the friction between the wall and liquid ice.
(3) The average heat removal rate is correlated by the following equation within the deviation of <plus-minus>15
DELTAh_<ave>=1.131 Q_a^<1.127>DELTAT^<1.248> Less
Research Products (5results)