NUMERICAL SIMULATION OF THE SWIRL BURNER COMBUSTION PROCESS IN A 1925T/H COAL-FIRED BOILER

摘要

A numerical simulation on the combustion process in a 1925t/h coal-fired boiler with swirl burner was performed by the software of FLUENT. And the combustion characteristics were discussed based on the numerical simulation. It was found that, the bigger Over-Fire Air rate, the less NOx would produce while the combustion efficiency would decrease. There were great effect of swirling strength on firing speed and burnout of pulverized coal air flow. The rich/lean ratio of primary air also had big effect on boiler combustion efficiency. In order to keep combustion efficiency, primary air flow should be adjusted according to fuel characteristics. It was very important for coal-fired boiler combustion adjustment that adjusting the amount of OFA, primary air, secondary air and tertiary air appropriately when other factors maintained constantly.