Biomass Boiler Combustion Methods
Biomass Boiler Combustion Methods
Due to the special characteristics of biomass fuels themselves and their combustion processes, the selection of design and operation methods for biomass boilers should start from the combustion characteristics of different types of biomass in order to ensure the economic and reliability of biomass boiler operations and improve the efficiency of biomass development and utilization.
The main problem with biomass combustion is agglomeration, ash accumulation, and slagging. In addition to the fuel’s own properties (mainly referring to the composition of ash), a reasonable boiler structure design, and the selection of operating parameters during boiler operation are also crucial. For example, flue gas temperature, heat transfer surface temperature of pipes, materials, and location, combustion environment, oxygen content in flue gas, etc. By strictly controlling the combustion temperature at the bed layer and furnace outlet, separation performance, excess air coefficient, and flue gas flow rate at the tail section, problems such as ash accumulation and slagging that occur when burning straw-like biomass can be avoided and resolved.
Since the ash formed by the combustion of straw-like biomass mainly enters the tail section in the form of fly ash, according to the analysis of ash composition, silicon, potassium, sodium, and calcium contents are relatively high in the ash. The adhesion of ash on the heat transfer surface of pipes is much more severe than wear. Therefore, selecting a reasonable flue gas flow rate at the tail heat transfer surface can prevent ash accumulation, while dedicated soot blowing systems and bag filter dust collectors can effectively collect fly ash in flue gas.