Identification by inverse method of a thermal contact conductance field in a metallurgical reactor

This work provides an inverse estimation method for the prediction of the thermal contact conductance field between two materials layers inside the wall of a metallurgical reactor. In this case, it is very important to determine the thermal contact conductance in the wall because if it's importance on the heat balance. This technique allows identifying and correcting contact defaults before the reactor is started. This study uses an inverse method based on the conjugate gradient method with adjoint problem, to achieve this identification. Firstly, this method is validated for three test cases with different thermal contact conductances at the interface between two materials usually found on the side wall of a metallurgical reactor: a refractory layer in contact with a steel plate. Secondly, additional tests are carried out to study the evolution of the error estimation as a function of two adimensional parameters, the Biot number and the thermal conductivity ratio k*. It is shown that in order to have a good estimation, the Biot number must be larger than 0.005 while k* needs to be larger to 1. This method of estimation of the thermal contact conductance field is innovative and non intrusive.