Analysis of radiation heat transfer in reheating furnace under oxy-fuel conditions
In order to obtain the optimal oxygen volume fraction during oxy-fuel combustion in the reheating furnace,the weighted-sum-of-gray-gases model ( WSGG) was improved to make it suitable for the calculation of gas radiation heat transfer under oxy-fuel combustion conditions. The improved model was used to study,the effects of temperature and oxygen volume fraction on furnace gas emissivity and heat flux density on the surface of slab under oxy-fuel combustion conditions in a reheating furnace. The results show that with the increase of furnace gas temperature,the emission of furnace gas first increases and then decreases in the oxy-fuel combustion method and dry flue gas circulating combustion method,and the emissivity of furnace gas continues to decrease in the wet flue gas circulation method;Under the oxy-fuel combustion method,the decrease of heat flux density on the surface of slab gradually increases when the furnace gas temperature exceeds 1300 K,while under the flue gas circulating combustion method,the heat flux density on the surface of slab decreases linearly with the furnace gas temperature;With the increase of oxygen concentration,the heat flux density on the surface of slab in the oxy-fuel combustion method increases significantly. In this method,the oxygen concentration in the preheating,heating,and soaking sections of the reheating furnace using oxy-fuel combustion is 30％～34％,28％～31％,and 26％～28％,respectively. For the flue gas recirculation combustion method,as the oxygen concentration increases,the increase in heat flux density on the surface of slab is relatively small.
oxy-fuel combustionWSGGemissivityradiation heat transfer
万方数据
维普
