Heat transfer in bare and insulated electrical wires with linear temperature-dependent resistivity

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• 作者：J.P. Brito Filho ^{jbrito@ufpe.br}
• 关键词：Thermal analysis ; Heat conduction ; Electrical cables and wires ; Ampacity ; Electrical resistivity
• 刊名：Applied Thermal Engineering
• 出版年：2017
• 出版时间：5 February 2017
• 年：2017
• 卷：112
• 期：Complete
• 页码：881-887
• 全文大小：805 K
• 卷排序：112

文摘

This article presents the evaluation of the electric current-carrying capability (ampacity) of an electrical wire, covered or not with an insulating material, carrying a direct electrical current, taking into account the electrical resistivity temperature-dependence of the wire core. The evaluation was based on a heat transfer model consisting of an infinitely long two-layer cylinder with temperature-dependent volumetric heat generation under boundary conditions of the first and third kinds.A comparison between the closed form solutions reported in this manuscript versus the classical solutions, i.e. the ones in which the electrical resistivity is considered temperature-independent, showed that the they allowed for predicting the situations in which one must consider the temperature-dependent resistivity of the wire core on the ampacity and the influence of the convection coefficient of heat transfer. The closed form solutions were successfully validated using the ANSYS/Steady-state thermal software.