Creation of Model and Calculation of Thermal Processes in the Ring Graphite Electrode of the Plasmatron

Ramil T Nasibullin,Ramil Sh Sadriev,Almaz Sh Sadriev,Lenar R Sarimov

doi:10.14419/ijet.v7i4.36.24950

Abstract

This paper presents the theoretical and experimental material obtained in the study of the erosion and thermal state of the ring graphite electrode for a plasmatron. Thermal processes in graphite electrodes of plasmatrons are quite complex and multifaceted. A mathematical model of thermal processes that occur at the ring electrodes of plasmatrones has been developed. The mathematical model is based on the differential heat conduction equation for a ring electrode in cylindrical coordinates. With the use of this mathematical model, the inverse problem of heat conduction is solved: determination of the regularities of the heat exchange process by the temperatures of individual points on a solid surface. An experimental study of the temperature distribution at the end of the electrode and along the length of the electrode was carried out. Experiments have shown that the temperature on the side surfaces drops sharply towards the cold end of the electrode. When reducing the length of the electrode, the maximum temperature at the end decreases, and the temperature on the inner and outer edges of the electrode increases slightly. The most significant factors determining the temperature field at the end of the ring electrode are the power and size of the heat source. Comparison of the results of experimental studies and mathematical modeling showed a match with an acceptable degree of accuracy.

Highlights

If the dependence on heat flux or on temperature is known at the boundary of a solid, the temperature distribution in the whole body can be determined
In many cases, when analyzing dynamic heat transfer processes, the law of change in heat flux or surface temperature must be determined from the data of temperature measurements at one or several internal points of the solid
The authors stipulate the range of applicability of the obtained asymptotics (0.5 ≤ z ≤ 150 mm, where z is the heating depth) and further show how with its help, provided that the diameter of the plasmatron head is known, the inverse problem can be partially solved: to estimate the power of the surface heat source

Summary

Introduction

If the dependence on heat flux or on temperature is known at the boundary of a solid, the temperature distribution in the whole body can be determined. In many cases, when analyzing dynamic heat transfer processes, the law of change in heat flux or surface temperature must be determined from the data of temperature measurements at one or several internal points of the solid. Taking into account the above analysis of literary material in the study of heat transfer processes during electric arc processing of materials, numerical simulation and creation of engineering methods for calculating temperature fields in graphite electrodes of a plasma generator are the most relevant

Methods

Results and discussion

Summary

Conclusions