Research On The Method Of Thermal Economy Analysis Of Steel Rolling Reheating Furnace Based On Subsection Heat Transfer Calculation

Since the ’ double carbon ’ goal was put forward,the state has vigorously promoted energy conservation.The ’ 14 th Five-Year Plan ’ comprehensive work plan for energy conservation and emission reduction points out that we should organize and implement key projects for energy conservation and emission reduction,further improve the policy mechanism for energy conservation and emission reduction,and promote a substantial increase in energy efficiency,so as to lay a solid foundation for achieving the goal of carbon peak and carbon neutrality.The energy conservation and emission reduction work of the steel industry will be the top priority of the national energy conservation and emission reduction work in the future,and the energy conservation work of the steel rolling process is also an indispensable part of it.Therefore,it is of great significance to study the thermal economy analysis method of steel rolling reheating furnace and tap its potential for energy saving and consumption reduction to help realize the goal of ’ double carbon ’.Firstly,this thesis studies the energy efficiency analysis method of steel rolling reheating furnace.Based on the first law of thermodynamics and the second law of thermodynamics,the heat balance analysis model and exergy balance analysis model of reheating furnace are constructed.The heat loss and irreversible exergy loss generated in the process of energy utilization of reheating furnace are calculated,and the main influencing factors of energy efficiency of reheating furnace are analyzed.Based on the field operation test data of the heating furnace,combined with the heat balance and exergy balance model,the balance table is constructed,the energy flow diagram and exergy flow diagram are drawn,and the input and expenditure items of the heat flow and exergy flow of the heating furnace are clarified.The thermal efficiency of the heating furnace is 53.05 %,and the exergy efficiency is 41.77 %.The maximum heat loss is the exhaust heat loss,accounting for 29.4 %,and the maximum exergy loss is the irreversible exergy loss of the heat transfer process,accounting for 25.15 %.In order to further clarify the internal heat transfer mechanism of the heating furnace and find the optimal operation scheme for improving the energy efficiency of the heating furnace,this thesis divides the model into four sections according to the actual physical section of the heating furnace.The heat exchange calculation and heat balance calculation of each section are carried out independently.According to the countercurrent heating process,the calculation model of each section is coupled to construct the segmented heat transfer model of the heating furnace.Based on the field test data,the model is verified.The thermal efficiency error rate is 1.64 %,the billet heat load error rate is 1.29 %,and the gas flow error rate is 2.48 %,which meets the error accuracy requirements of the model.Based on the segmented heat transfer model of the heating furnace,the effects of preheating gas,air temperature and excess air coefficient of each section on the thermal efficiency of the heating furnace and the gas consumption of each section are explored.Under the condition that the total heat load of the billet in the model is unchanged,the influence of the heat load distribution scheme of each section on the energy efficiency of the heating furnace is explored.By appropriately increasing the heat load of the billet in the second heating section,the thermal efficiency of the heating furnace can be improved and the gas consumption can be reduced.