A Thermal System Model for a Radiant-Tube Continuous Reheating Furnace

摘要

A thermal system mathematical model developed for a gas-fired radiant-tube continuous reheating furnace is discussed. The mathematical model of the furnace Integrates submodels for combustion and heat transfer within the radiant tube with models for the furnace enclosure. The transport processes occurring in the radiant tube are treated using a one-dimensional scheme, and the radiation exchange between the load, the radiant-tube surfaces, and the furnace refractories are analyzed using the radiosity method. The continuous furnace operation is simulated under steady-state conditions. Model simulations of load surface temperature variation compare well with measurements in an industrial galvannealing furnace. The scope and flexibility of the model are assessed by performing extensive parametric studies using furnace geometry, material properties, and operating conditions as input parameters In the model and predicting the thermal performance of the furnace. The various parameters studied include the effects of load and refractory emissivities, load velocities, properties of the stock material, and variations In the radiant-tube designs.