Modeling of thermal processes when melting ice on power lines

Abstract

An analysis of the problem of ice formation on power line wires was carried out, and a review of work in the field of melting ice on various lines was carried out. Existing achievements and problems are noted. One of the reasons for the low equipment of lines with automated melting systems is the need to transfer the line from the operating state to the melting mode. One way to solve the problem is to combine these modes by loading the line with additional current without increasing the power transmitted to consumers. A set of issues on modeling thermal processes in the ice shell of power line wires during ice melting is considered. Limiting the power of heat generation in wires leads to the need to build a sufficiently accurate mathematical model to guarantee melting at different values of wind speed and temperature. A study of wire heating processes was carried out using models of stationary and non-stationary thermal conductivity. An algorithm is proposed for solving the thermal problem when a heated wire penetrates an ice shell, based on simulating the movement of the interface between the solid and liquid phases of water. The features of modeling the melting and crystallization process using a numerical method are described. When ice transitions to a molten state, melting reflects a change in density and the formation of an air gap, accompanied by a significant decrease in heat flows to the lower region of the ice shell. The results of numerical modeling of the process of melting an ice shell with a wire at different values of the convective heat transfer coefficient are presented. When analyzing the modeling results, conditions were identified for the occurrence of unacceptable overheating of a wire freed from ice. Various options for constructing a control system for the smelting process have been proposed to prevent overheating of the wire.