1. Determine the relevant information of the boiler
• Boiler capacity and efficiency
• Furnace back pressure
• Fuel
• Burner fuel inlet pressure• Burner capacity adjustment method
2. Calculate the burner capacity. Burner capacity = boiler capacity / efficiency
Example: Boiler capacity 6,500 kW, efficiency 90% → Burner capacity = 6,500 kW / 0.9 = 7,220 kW.
3. Gas burner: Required gas flow [m3n/h] = (burner capacity [kW] x 3.6) / gas calorific value [MJ/m3n].
Example: Burner capacity = 7,220 kW → Required gas flow = (7,220 kWx 3.6)/35.8 MJ/m3n= 726 m3n/h,
where 35.8 MJ/m3n is the calorific value of natural gas.
4. Oil burner: Calculate the required oil flow [kg/h]. Required oil flow [kg/h] = (burner capacity [kW] x 3.6) /
oil calorific value [MJ/kg].
Example: Required burner capacity = 7,220kW → Required oil flow = (7,220 kW x 3.6)/42.7 MJ/kg = 609kg/h,
where 42.7MJ/kg is the calorific value of light oil.
5. Check the external dimensions of the burner, especially the burner head, for suitability for the application;
the length of the burner head should be such that when installed the burner head is flush with the furnace
wall or about 10 to 20 mm inside the furnace.
6. Check the flame size in the flame size table. Note that the flame must not touch the wall furnace.
7. Accessory requirements must also be considered: gas pressure regulator, extraction device, boiler
thermostat/pressure regulator.
1. Burner capacity = boiler capacity/0.9 (when boiler efficiency is 90%)
2. Steam boiler: 1 ton/hour steam ≈ 700kW boiler capacity
3. Light oil: 1 kg/h ≈ 11.86 kW Burner capacity calorific value 42.7 MJ/kg
4. Heavy oil: 1 kg/h ≈ 11.22 kW Burner capacity calorific value 40.5MJ/kg
5. Natural gas: 1 cubic meter n/h ≈ 10kW Burner capacity calorific value 35.84 MJ/m3n
6. Combustion air volume:
Gas burner: Required combustion air volume,Each 10kW burner capacity is 12~13m3/H.
Oil burner: Required combustion air volume.Each kilogram of oil burned [kg/h] is 13.5 m3/H.
7. Oil extraction, filtration, and preheating devices
Required when burning heavy fuel oil. When the burner capacity is greater than 2MW, a transfer pump unit is
always required, including when used with light fuel oil.
The minimum pump output [kg/h] required for this purpose can be calculated as follows:
Minimum required output [kg/h] = (combustion oil flow kg/h + 150 to 200 kg/h) * 1.25 to 1.3, where the
expression in brackets represents the preheating oil flow to each burner.