Combustion characteristics and design of hot water boiler

Abstract

In order to understand the combustion characteristics of biomass, a detailed comparison with coal was made. There are many differences between biomass and coal in combustion characteristics. The burning rate of biomass is much higher than coal. The burning rate of biomass char is also higher than coal char. During biomass combustion, HCl, SO2 and NOx emissions mainly concentrate in volatile combustion stage, while CO2 emission mainly concentrates in char combustion stage. The slagging tendency of biomass ash is severer than coal ash and the adhesive force of biomass ash is higher. However, the wearing tendency of biomass ash is minor. Aiming at the particularity of biomass fuels, this paper briefly introduces the design of biomass hot water boilers. On this basis, a 2.8 MW biomass hot water boiler was developed and tested under the loads of 1.7 MW and 2.8MW. The running results show that the carbon content of bottom slag significantly decreases as the load increases. The boiler efficiency is higher than 85% under both loads.