Air distribution issues in coal-fired boilers
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1. The pulverized coal furnace has 4 layers for primary air and 8 layers for secondary air. How should this be allocated? 2-1-2-1-2-1-2 or 2-1-2 2-1-2 2-1-2? 2. Premise: Reduce the air volume of the secondary air at the lowest level; accordingly, reduce the amount of primary air and fuel used as well ； Question: Do the secondary air, primary air, and fueler at other upper levels have an impact? Should the air volume and coal powder quantity be reduced accordingly? I hope all the sea friends can help me analyze it. Thank you very much!~
The air distribution schemes for your burners over a period of two weeks both involve staged air distribution; the characteristic is that the primary air inlets are arranged separately from the secondary air inlets, with the secondary inlets even being more concentrated. This approach is suitable for coal types that catch fire easily, such as bituminous coal. The secondary air at the lowest level plays a significant role; in addition to aiding combustion, it also helps to support the flame. Its effect on disturbing and mixing the flames in the upper layers is greater than that of the secondary air located higher up. Therefore, if the boiler load is to be reduced, it is advisable to first decrease the amount of secondary air in the upper layers. If it is necessary to reduce the secondary air at the lower level, this will certainly have an impact on the ignition of the primary air in those upper layers, especially near the primary air nozzles.
This post was last edited by john1628 on 2015-12-29 08:45. Regarding the issue of secondary air: Secondary air serves to support the coal. If the amount of secondary air is reduced by 10% while the oxygen concentration is increased by 4%, this reduction in air volume will enhance the rigidity of the flame, ensuring thorough combustion at the bottom, and allowing the overall temperature to be increased in a controlled manner. Is this approach feasible?
The lower secondary air flow should not be reduced; if reduction is necessary, it should start with the upper secondary air flow