A Dynamic Thermal System Model For a Low Inertia Furnace

A dynamic thermal system model developed for a gas fired, low-inertia, batch-type reheating furnace is discussed in this paper. The mathematical model of the furnace integrates the models for heat transfer within the enclosure with the model for the load. The transport processes occurring in the flat radiant heaters are not treated, but the radiation exchange between the load, the radiant heater surfaces, and the furnace refractories are analyzed using the radiosity method. The batch furnace operation is simulated using a dynamic thermal model. The scope and flexibility of the model is assessed by performing extensive parametric calculations using the furnace geometry, material properties and operating conditions as input variables of the model and predicting the thermal performance of the furnace. The various model parameters studied include the size and radiative properties of the load, thermophysical properties of the stock material and the flat radiant heater designs