| Project/Area Number |
62550426
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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 |
建築環境・環境工学
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| Research Institution | Tokyo University of Science |
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Principal Investigator |
SUGAWA Osami Science University of Tokyo, Lecturer, 火災科学研究所, 講師 (60162856)
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| Co-Investigator(Kenkyū-buntansha) |
MORITA Masahiro Science Univ. of Tokyo, Lecturer, 理学部・応用数学, 講師 (10120221)
KAWAGOE Kunio Science Univ. of Tokyo, Professor, 火災科学研究所, 教授 (30103039)
水野 智之 東京理科大学, 火炎科学研究所, 助手 (30120215)
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| Project Period (FY) |
1987 – 1989
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| Project Status |
Completed (Fiscal Year 1989)
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| Budget Amount *help |
¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 1989: ¥100,000 (Direct Cost: ¥100,000)
Fiscal Year 1988: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1987: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Keywords | Clean room / Fire induced flow / flow visualization / plume / plume temperature / fire source / 火災上昇気流 / クリーンルーム / シミュレーション / 下降流(ダウンフロー)対向流 / 火炎気流 / 2次元シミュレーション / 対向流 / プルューム |
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| Research Abstract |
An interaction between fire induced upward flow and downward ventilation flow in a clean room is a matter of some concerns in the fire safety and smoke detection. Generally, the buoyant plume from an early stage of fire is very weak and is easily diluted with ambient air flow of the ventilation before the fire products reaching to a fire detector. In order to ensure adequate fire safety for clean rooms, it is important to design the early fire detecting system depending on the flow behavior produced by the complex of upward fire flow and downward ventilation flow.
Full scale model clean rooms, 6.4m(W) x 9m(L) x 3.2m(H) and 3.8m (W) x 3.8m(L) x 3.0m(H), were used with a line or a circular model fire source of 6kW. Methylalcohol was used as a fuel. Temperature, velocity, and dynamic pressure were measured every 10 sec and flow visualization by a smoke wire and/or smoke candles was also carried out simultaneously. Downward ventilation velocity ranging 20 cm/sec - 45 cm/sec was employed.
Cen
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ter-line upward velocity in a characteristic form of v/Q^<1/5> and temperature rise (DELTAT) in a plume above a fire source were plotted against characteristic height with heat release rate of z/Q^<2/5>. These experimental data were obtained with downward ventilation flow. v/Q^<1/5> = A (z/Q^<2/5>)^n, DELTAT = B (z/Q^<2/5>)^<2n-1>. The values of A and B for the plume region with downward ventilation flow of 24 - 25 cm/sec are estimated as A = 0.2 - 0.3 and B = 3 - 5, respectively with n = -1/3. It was clearly found that the flow behavior based on temperature rise and velocity along the center-line of the fire plume are similar to those in the fire plume without downward ventilation flow except the flame intermittent region. The decreasing rates of A and B are greater than those in the flow without ventilation flow. Complex flow induced by upward flow of fire plume and downward ventilation flow made rapid diffusion of fire products (smoke and gas) within ;the clean room in a few minutes. There is no enough time to protect the cleanliness of the clean room from smoke diffusion from a fire unless very rapid fire detecting system will presents. Less
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