| 摘要 |
PURPOSE: A method which is capable of calculating radiation heat having credibility even when supply of cooling water is stopped at one or more staves of the furnace body by analyzing thermal conduction for staves of the furnace body using finite element method and calculating thus applying radiation heat. CONSTITUTION: The method for calculating radiation heat from staves of the furnace body in COREX melting furnace comprises first step of determining the range in which temperature of thermocouples is capable of being changed, and setting the minimum of the range as the lowest temperature and the maximum of the range as the highest temperature; second step of obtaining temperature distribution by using the lowest temperature as temperature of the boundary surface at position of the thermocouples, applying convection current boundary condition in case that cooling water is steadily flown on the boundary surface of the inner surface of cooling pipes, applying adiabatic condition in case that supply of cooling water is stopped, applying convection current condition to the boundary surface of the outer surface of metal case and applying adiabatic conditions to the rest of boundary surfaces, thereby solving a thermal conduction equation using finite element method; third step of obtaining radiation heat of the furnace body using the temperature distribution using the following equation I: Qr=Q1+Q2=hAs(Ts-Ta)+QHAt(Tt-Tw) where Qr is radiation heat emitted from stave , Q1 is radiation heat emitted from iron shell, Q2 is radiation heat emitted from cooling pipe, h is thermal conductivity coefficient on outer surface of iron shell, As is area of stave, Ts is mean temperature on outer surface of iron shell, Ta is atmosphere temperature, H is thermal conductivity coefficient in cooling pipe, At is sectional area of cooling pipe, Tt is mean temperature on outer surface of cooling pipe, and Tw is temperature of cooling water; fourth step of repeating the above steps from the second step by increasing temperature of the thermocouples of the second step as much as a certain amount of temperature if the temperature of the boundary surface is lower than the highest temperature and proceeding the following fifth step if the temperature of the boundary surface is higher than the highest temperature after determining whether temperature of the boundary surface at the position of thermocouples is higher or lower than the highest temperature; fifth step of deriving relation of the set thermocouple temperature (T) and obtained radiation heat (Qr) into a linear expression; and sixth step of obtaining radiation heat by substituting the actually measured temperatures of the thermocouples for the obtained linear expression.
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