Boiler efficiency shows how much of the energy given by fuel is transferred to steam. This tool calculates efficiency by direct (input-output) method: simply select the fuel type and enter the measured feed water (or steam) flow rate and fuel consumption.
Formula
Hu is the lower calorific value of the fuel (kcal/Sm³, kcal/kg or kcal/L; the typical value comes when you select the fuel), x is the steam dryness fraction (default 98%). hf and hfg are calculated at boiler pressure, hfw at feed water temperature, with IAPWS-IF97. If you are using a feed water meter, steam flow = feed water − blowdown; the heat discharged with blowdown is counted as useful output according to EN 12953-11 and ASME PTC 4, and the value that counts blowdown as a loss is also shown separately.
Example
If 1,000 kg/h feed water and 76 Sm³/h gas consumption are measured with 80 °C feed water in a boiler burning natural gas (Hu = 8,250 kcal/Sm³) and operating at 10 bar(g) pressure, the useful heat is 668.3 kW, the fuel heat is 729.2 kW and the boiler efficiency is 91.64%; at a rated capacity of 2,000 kg/h, the load factor is 50% (13.16 kg steam with 1 Sm³ gas).
Çiftel Kazan’s boilers operate with thermal efficiency between 85-95% depending on type, fuel and operating conditions. For steam boiler selection, you can take a look at our steam boiler guide and get free quote for your project.