• 방재와보험
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• s.112
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• pp.51-58
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• 2006

지난 호에 이어 이번 호에는 SFPE 방화공학핸드북의 제4부, 제9장 및 제11장에서 설명하고 있는 내화피복 강부재와 내력 목재 부재의 내화성능 계산방법에 대해서 소개하고, 제3부, 제11장에서 다루는 개방형 탄화수소 화재의 복사열선속을 계산하는 방법과, 이러한 복사열선속의 인체 위험성(제2부, 제6장)에 대해 소개한다

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.7
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• pp.1684-1690
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• 1995

A large time asymptotic solution for an unsteady heat conduction problem of a coated hot wire thermal conductivity measurement process was theoretically found. The solution revealed that the slope of wire temperature versus logarthmic time, which is used to evaluate the thermal conductivity, remains unchanged for large values of time even if a layer of coating is present on the hot wire. The significance of this result is that the thermal conductivity of an electrically conductive fluid can be measured with a coated hot wire using the same conversion relation as for a bare wire.

• Transactions of the Korean Society of Mechanical Engineers
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• v.8 no.2
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• pp.154-161
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• 1984

A modified technique of the transient hot wire method to measure the thermal conductivity of fluid has been described in this paper. The thermal conductivity of fluid can be obtained by acquiring wire temperature as a function of time. Multiplication of the inverse slope of the temperature versus logarithm of time by an instrumental constant gives the thermal conductivity. The constant voltage was applied to Wheatstone bridge circuit. The wire temperature can be measured as a function of time precisely with the aid of the data acquisition system composed of a microprocessor and an analog-digital converter. The thermal conductivity of the electrically conducting fluid has been measured with the insulated hot wire coated by electrically non-conducting material. The effect of the coated insulation layer on the thermal conductivity has been examined, in which it is confirmed that the thermal conductivity of electrically conducting liquid can be determined by the transient coated hot wire method. Thermal conductivities of methanol, carbontetrachrolide, Freon-22 and glycerin have been measured at room temperature in the pressure from 0.1MPa to 35.1MPa. The experiment has been performed to compare the data from the bare and the coated wires, and the results are satisfactory.