In order to analyze the influence of co-firing process of biomass gas with coal on combustion process in boiler

the furnace structure was meshed by the GAMBIT software.On the basis of Fluent software

the model for co-combusiton of biomass gas and coal was established

and the co-firing process was numerically investigated.The temperature field

velocity field and flow field around the primary air nozzles were analyzed

under conditions with varying biomass gas co-firing ratios.The results show that

when the biomass gas ratio increased

the peak temperature in the furnace cross section decreased gradually

while the temperature at the burner area increased.The air velocity and rotation strength in the center part of the furnace enhanced and the flow field of the primary air changed little with increase of the biomass gas co-firing ratio.