Why does the combustion fan in the incinerator use frequency conversion to stabilize the outlet pressure and then adjust the flow rate through dampers?
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As the title suggests, why does the combustion furnace’s auxiliary blower use frequency conversion to stabilize the outlet pressure and then adjust the flow rate through dampers? What is the reasoning behind this? Could the frequency converter not be used directly to control the air volume? Wouldn’t that be more energy-efficient, as it would eliminate the need to maintain a high outlet pressure? Hope someone with more experience can give some advice :)
To add further clarification, this adjustment process 1 involves changing the performance curve of the fan through frequency conversion, and 2 it also alters the characteristics of the ducts by adjusting the dampers; it’s not clear what control principle is behind this.
The outlet pressure of the fan can be changed by varying the frequency; the higher the speed, the higher the outlet pressure； Vane adjustment controls the fan flow rate. In terms of doing work, this is more energy-efficient.
To control the outlet pressure and flow rate of the fan, either of the two methods can be used. Variable frequency control is certainly better than adjusting the dampers; using both methods is a waste of resources. Either the designers don’t understand this, or the installers don’t, in order to sell more equipment.
It seems to depend on what kind of fan is being used For centrifugal fans, variable frequency drives are better for controlling air volume, while variable frequency drives are used to control air pressure in Roots fans