Numerical Simulation Of The Gasification Based Biomass Co-firing In Tangentially Fired Pulverized Coal Boiler

Gasification based biomass co-firing was a low-risk,low-cost technology that could make full use of the existing boiler system and technology.Compared to directly co-firing biomass and coal,it avoided biomass delivery into the boiler,reduced boiler slagging and avoided altered ash characteristics.In the study,numerical simulation of co-firing producer gas from biomass gasification and coal in a 600MWe tangential PC boiler was carried out with FLUENT software.The results showed that the reduction of NO emission could be achieved and the temperature decreased when co-firing.The effect of co-firing on combustion efficiency was slight.The temperature decreased with the proportion of biomass gas increased. The mean temperature decreased by 300K when the percentage of the biomass gas increased to 50%.The convection heat transfer area should be increased or the biomass gas should be limited to a low percentage to achieve higher boiler efficiency.NO emission decreased with the percentage of the biomass gas increased and the NO removal rate could reach 71%.The results showed that when the biomass gas was injected from the lowest layer of the burner,it could receive higher temperature and lower NO emission.