Numerical simulation and analysis of entropy generation and exergy equilibrium of the thermal process in a regenerative billet reheating furnace

A typical heating unit model was defined to simulate the entropy generation rate distribution of regenerative billet reheating furnace. Energy efficiency of whole furnace under different energy-saving measures was further investigated. The results indicated that radiative heat transfer and combustion are main contributors to the entropy generation. For whole furnace, if the billet charging temperature increases from 25°C to 600°C, the exergy destruction rate decreases from 29.6% to 20.2%, and the exergy efficiency increases by 7.2%. Increasing the fuel supply in preheating zone by 0.68 kg/s can also reduce irreversible exergy loss by 6.8%, and increase exergy efficiency by 3.1%.