| Project/Area Number |
08455108
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Thermal engineering
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| Research Institution | Okayama Prefectural University |
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Principal Investigator |
FUKUTANI Seishiro Okayama Prefectural Unversity, Department of System Engineering, Professor, 情報工学部, 教授 (40026208)
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| Co-Investigator(Kenkyū-buntansha) |
KUNIOSHI Nilson Okayama Prefectural Unversity, Department of System Engineering, Associate Profe, 情報工学部, 助教授 (30254577)
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| Project Period (FY) |
1996 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥4,300,000 (Direct Cost: ¥4,300,000)
Fiscal Year 1998: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1997: ¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 1996: ¥2,200,000 (Direct Cost: ¥2,200,000)
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| Keywords | hydrocarbon flames / preheating / dilution / combustion characteristics / 炭化水素火災 / 燃料流束 / 予混合火災 / NOx |
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| Research Abstract |
The combustion characteristics of diluted and preheated methane-air premixed and diffusion flames were analysed through flat-flame and counterfiow diffusion flame models. The results concerning to the premixed flame, or the flame in which the mixing rate of methane and air is very high, can be summarized as follows :
1. In flames whose adiabatic flame temperature is higher than 2200 K, the fuel flux can be raised by diluting and preheating the metane-air mixture, independently of the air ratio. For the NO emission, in general, the greater the oxygen ratio the better, but there are optimum values for both the oxygen ratio and the preheating temperature.
2. For flames whose adiabatic flame temperature is below 2000 K, both fuel flux and NO emission do not show strong dependence with neither dilution nor preheating. For these flames, preheating and dilution should be considered as the means to keep the condition of excess of enthalpy.
For the diffusion flame, or the flame in which the mixing between methane and air is very slow, the following results were achieved :
1. The NO emission level can be expressed as a function of the maximum flame temperature. In other words, neither the dilution nor the preheating of the air have any special effect in reducing the NO level.
2. Therefore, the effect of dilution and preheating can not be achieved in flames in which the mixing between fuel and air is slow.
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