Thermal modelling of a brazing process of vacuum interrupters

This work describes a three-dimensional thermal finite-difference analysis of a brazing process of vacuum interrupters. The overall objective is to develop a reliable numerical model to be used to optimise the number of interrupters and the configuration in which these are placed within the furnace so that the process duration and cost are minimized. Significant simplification tasks are performed during the discretization stage bearing in mind the high number of interrupters, their complex geometry and the fact that the heat exchange is mainly governed by a radiation mechanism. As a first step, the simplified models of the interrupters are validated. Thermal loads to be applied and heat leaks of the furnace are calculated based on some earlier tests. Numerical results indicate that heat fluxes and heat leaks are accurately considered in the model and the general thermal behaviour is correctly predicted. The model is concluded to be effective to study and optimise the brazing process duration and cost.