What is the excess air coefficient for burning biomass pellets?
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As the title suggests, what is the excess air coefficient for burning biomass pellets during thermal calculations?
NB/T47062-2017, Clause 7.2, provides the recommended value for the excess air coefficient at the smoke exhaust of the final stage of the heating surface. The furnace coefficient of a certain 2-ton DZL-type biomass boiler is 1.35, the coefficients for the tube bank areas are 1.4/1.475 respectively, and that of the economizer is 1.55. The values for a certain 6-ton DZL model are 1.35/1.4/1.5/1.6 respectively.
Hello, may I ask whether the horizontal internal combustion chamber boilers of the WNS series belong to layer-fired boilers or fluidized bed boilers?
Horizontal internal combustion chamber boiler burning biomass pellets
For WNS shell-and-tube boilers that use biomass burners, it is possible to first submit a design proposal based on fuel or gas requirements; after the proposal is approved and stamped, a modification plan can be prepared (at this point, it is only necessary to file the details with the local boiler inspection agency). The calculations are carried out as if it were a room-type burner, using similar values – for example, if it is a fluidized bed burner, then values specific to fluidized bed burners are used. It is also acceptable to rely on the experience of those who have worked in this field, as the boiler inspection agencies are not as strict as provincial authorities.
Our boiler is of the WNS-10-1.6 type; it uses rice husks as fuel, and its excess air coefficient is 1.6 for reference