To realize nitric oxides(NOx) emission regulation below 200mg/m3 (O2 volume fraction at 3.5%) in heating furnace fired refining gas

a high efficiency low nitrogen reconstruction scheme by reburning technology was proposed

and it was confirmed by numerical calculation and industrial test. The software of FLUENT was applied to investigate the effects of reburn refining gas ratio and primary area stoichiometric ratio on the distribution of temperature and NOx mass concentration at different sections

generation

reduction characteristics of NOx and unburned rate of refining gas. According to the optimized numerical calculations

the reconstruction was implemented and industrial test was carried out for one week. The results showed that

with the reburn fuel ratio increasing

the proportion of high temperature space decreased

the amount of thermal NOx reduced and reduction increased

the NOx reduction efficiency by reburning impact firstly increased and then decreased. The highest NOx reduction efficiency by reburning impact when the reburn fuel ratio was 0.20. Increasing the reburn fuel ratio and decreasing the primary area stoichiometric ratio could increase the NOx reduction efficiency

but the unburned fuel ratio increased meanwhile. When the reburn fuel ratio between 0.15~0.20 and the primary area stoichiometric ratio between 1.15~0.20

the greatest and average values of NOx mass concentration were 160mg/m3 and 130mg/m3 (O2 volume fraction at 3.5%) respectively.