1988 Fiscal Year Final Research Report Summary
THE LONG-TERM PRESERVATION OF FROZEN SOIL LAYER USING THE COLD WEATHER IN WINTER AND ITS THERMAL ANALYSIS
| Project/Area Number |
61560254
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
農業土木
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| Research Institution | Obihiro University of Agriculture and Veterinary Medicine |
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Principal Investigator |
FUJIO TUCHIYA OBIHIRO UNIVERSITY OF AGRICULTURE AND VETERINARY MEDICINE ASSOCIATE PROFESSOR, 畜産学部, 助教授 (30003130)
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| Project Period (FY) |
1986 – 1988
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| Keywords | Soil Freezing / Heat Pipe / Artificial Permafrost / Thermal Analysis / Finite Defference Method / 低温貯蔵 |
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| Research Abstract |
It was found that a large quantity of frozen soil layer was created in the cold winter weather by removing snowfall from the ground surface. After the deepest frost penetration was created in early March, the cover of thermal insulation material was necessary to preserve the frozen soil. Consequently the soil layers were kept frozen till the last ten days of June. In order to simulate this process, the finite difference method was tried for the thermal analysis and this simulation program contained the parts of freezing front zone having the latent heat between the frozen and the unfrozen. In this zone, the temperature range was assumed from 0゜C and -0.2゜C for the freezing process, whereas for the thawing process, it was assumed from 0゜C to -0.5゜C. The simulated results showed the good coincidenece with the measured values on the freezing process and the date of thawing, but the some diference from the thawing process. This reason is thought to result in the influence from the lateral thermal transfer. On the other hand, it was found that heat pipes was more useful for the creation of frozen ground by the field tests. Therefore it is possible to construct the low temperature storeroom by using the heat pipes. It is expect to develop the low temperature storage facility around the artificial permafrost without the cost of maintenance by using heat pipes in the cold region.
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