The Effects of Radiative Heat Transfer on the Flame Structures of Pulverized Coal Combustion
Project/Area Number |
63550159
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Research Category |
Grant-in-Aid for General Scientific Research (C)
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Allocation Type | Single-year Grants |
Research Field |
Thermal engineering
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Research Institution | Tokyo Institute of Technology |
Principal Investigator |
YOSHIZAWA Yoshio Tokyo Institute of Technology, Mechanical Engineering, Associate Professor, 工学部, 助教授 (00016627)
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Project Period (FY) |
1988 – 1989
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Project Status |
Completed (Fiscal Year 1989)
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Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1989: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1988: ¥1,500,000 (Direct Cost: ¥1,500,000)
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Keywords | Gas-Solid Two-Phase System / Flame Structures / Energy Recirculation / Thermal Radiation / Available Energy / 微粉炭燃焼 / 層流火災 / 火災構造 / エネルギー循環燃焼 |
Research Abstract |
This study is aimed at clarifying the effects of radiative heat transfer on the on the flame structures of pulverized coal combustion. Using a strict treatment of radiation, a numerical model is developed describing a one-dimensional model of a flame involving a burning mixture with inert particle suspensions. Experimental studies have been also executed simultaneously to confirm the results of numerical analyses. The results are classified into following three large groups. 1. Using the one dimensional model of a combustion system of a combustible gas mixture with particle suspension, it is disclosed that the suspended particles have two major effects. One is the suppression of combustion by the heat capacity of particles, and the other is the combustion augmentation by the energy recirculation based on radiative heat transfer. The latter effect is superior to the former one when the loading ratio is small and vice versa when it becomes large. The effects of the particle diameter and t
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he radiative properties of the particle have been clarified quantitatively. 2. The thermodynamic aspect of the combustion system with energy recirculation between products and reactants is discussed extensively, and a new characteristic temperature, the "adiabatic limit flame temperature", has been proposed. The concept of this temperature is very important, especially when considering the available energy and the efficiency of combustion systems. It is also shown that there exists the theoretical maximum of the available energy corresponding to the adiabatic limit flame temperature. 3. A farther study has been made on the flame structure and burning velocity in a gas-solid two- phase system where particle/wall and wall/wall radiative heat transfers have been taken into account as well as the radiative exchange between particles. The result shows that the important route of energy recirculation for combustion augmentation is the particle to wall and wall to wall radiative heat transfers and the wall to gas convective heat transfer. Less
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Report
(3 results)
Research Products
(18 results)