Abstract: Compared with traditional air combustion, oxygen-enriched combustion can increase the flame temperature, strengthen the radiation heat transfer in the furnace, reduce the exhaust heat loss, increase the volume fraction of CO2 in the flue gas, and is conducive to CO2 capture, so it has become a hot spot in the field of industrial furnace research. At present, most studies simply transform the whole heating furnace from conventional air combustion to oxygen-rich air combustion, and are limited to the single factor of oxygen volume fraction. In order to explore the influence of different oxygen-rich combustion arrangement forms and different oxygen volume fractions on the heating furnace thermal characteristics and slab heating process, two oxygen-rich combustion models (JC-1 and JC-2) with oxygen volume fraction of 21vol%~49vol% are established to study the effects of combustion of gas and fuel on the thermal characteristics of the furnace and slab heating characteristics by numerical simulation. The results show that compared with the JC-1 condition, the temperature distribution in the furnace under JC-2 condition is more uniform and the slab temperature is higher, so the oxygen-rich combustion arrangement under JC-2 condition is better than that under JC-1 condition. Slab temperature and furnace thermal efficiency increase with the increase of oxygen enrichment volume fraction, but the increase rate decreases gradually. When the oxygen volume fraction is between 21vol% and 37vol%, the heating furnace slab temperature and furnace thermal efficiency increase at a higher rate. In this volume fraction range, when the oxygen volume fraction of JC-1 and JC-2 increases by 1%, the furnace thermal efficiency increases by 0.44% and 0.47%, and the energy saving rate increases by 1.07% and 1.12%, respectively. Therefore, 37vol% is the optimal oxygen volume fraction for oxygen-enriched combustion. The significance of this study is to provide reference for the existing reheating furnace to implement the transformation of oxygen-rich combustion.

Key words: reheating furnace, oxygen-enriched combustion, numerical simulation, Thermal efficiency

摘要： 富氧燃烧具有提高理论燃烧温度、降低过剩空气系数和增强烟气辐射能力等优点，因此成为工业炉窑领域研究的热点。为了获得富氧燃烧布置形式及氧气体积分数对加热炉热工特性及板坯加热过程的影响，以某钢厂2250机组步进式加热炉为研究对象，建立了两种富氧布置形式(JC-1和JC-2)的燃烧模型，利用数值模拟研究了氧气体积分数从21vol%变化到49vol%时加热炉热工特性与板坯加热特性的变化。结果表明，JC-2工况的富氧燃烧布置形式优于JC-1工况；氧气体积分数为21vol%~37vol%时，加热炉板坯出炉温度、炉膛热效率的增长速率较高，因此37vol%为富氧燃烧最佳氧体积分数。本研究可为现有加热炉实施富氧燃烧改造提供参考。

关键词: 加热炉, 富氧燃烧, 数值模拟, 热效率