What Is The Effect Of Boiler Loading On Boiler Efficiency?

1.	What Is The Effect Of Boiler Loading On Boiler Efficiency?
Answer» The maximum efficiency of the boiler does not occur at full load, but at about two-thirds of the full load. If the load on the boiler DECREASES further, efficiency also tends to decrease. As the load falls, so does the value of the mass flow rate of the flue gases through the tubes. This reduction in flow rate for the same heat transfer AREA reduced the exit flue GAS temperatures by a small extent, reducing the sensible heat loss. Below HALF load, most combustion appliances NEED more excess air to burn the fuel completely. This increases the sensible heat loss.

Answer»

The maximum efficiency of the boiler does not occur at full load, but at about two-thirds of the full load. If the load on the boiler DECREASES further, efficiency also tends to decrease.
As the load falls, so does the value of the mass flow rate of the flue gases through the tubes. This reduction in flow rate for the same heat transfer AREA reduced the exit flue GAS temperatures by a small extent, reducing the sensible heat loss.
Below HALF load, most combustion appliances NEED more excess air to burn the fuel completely. This increases the sensible heat loss.

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