If you want to know the fuel consumption when selecting the diameter of a fuel pipe, a flowmeter and the size of a fuel tank, etc., or to know the air flow rate of a burner when calculating the flow rate for selecting an air supply & ventilating fan since a boiler is located in a basement, etc., pease calculate them by referring to the following examples.
The fuel consumption and air flow rate of a burner is always decided depending on the capacity of an installed boiler since a burner is not used by standing alone, but is used after one having the capacity necessary for a boiler is selected.
In other words, even though the maximum combustion amount of the burner, 'PG5N' made by this company is 840,000kcal/h, since it is only the maximum capacity that can be exerted in the air, the combustion amount can be different depending on the furnace pressure, etc., in case that a burner is mounted to a boiler. And even though the capacity can be used fully, since the boiler is overheated, it is impossible to exert the full capacity of a burner.
[Examples]
• In case of a hot water boiler with 600,000 kcal/h of heat capacity and 85% of heat efficiency using diesel as a fuel.
*Fuel Consumption*
Heat Input is calculated as follows.
600,000kcal/h(Capacity of Boiler) / 0.85(Efficiency) = 705,882kcal/h
And the fuel consumption is calculated as follows. 705,882kcal/h(Heat Input) / 10,200kcal/kg(Heating Value of a Fuel)= 69.2kgs/h. That is, the capacity of a burner is adjusted in order for diesel to be burnt at 69.2kgs/h.
*Air Volume*
Since the air volume necessary for fully burning 1kg of diesel is a sum of the theoretical amount, 12Nm3 + around 30% of additional amount, the volume is around 15.6Nm3(12Nm3 x 1.3).
Thus, the necessary air volume is calculated as follows. 69.2kg/h(fuel consumption) x 15.6Nm3(necessary air volume) = around 1,080Nm3/h
• In case of diesel, kerosene or byproduct fuel oil (light oil):
Fuel Consumption (kg/h) = {Capacity of Boiler (kcal/h) / 10,200}/ 0.85
Air Flow Rate(Nm3/h) = [{Capacity of Boiler (kcal/h) / 10,200}/ 0.85 ] x 15.6
• In case of natural gas (L.N.G):
Fuel Consumption (Nm3/h) = {Capacity of Boiler (kcal/h)/ 10,300}/ 0.85
Air Flow Rate(Nm3/h) = [{Capacity of Boiler (kcal/h) /10,300}/ 0.85]x 15.6
(Since the necessary air flow rate can be different by a little depending on a level of atmospheric pressure or some temperature difference due to the change of a season, it can be used at almost the same level within the tolerance regardless of whether gas or oil is used as a fuel.)
