COST OF STEAM

Calculation of Heat Required for Steam Generation

Fuel: Natural Gas

Amount of Steam Produced: 12 tons / h

Produced Steam Pressure: 10 bar

Heat required to generate steam: Q = m (hg-hf)

 

Q (kj): Amount of Heat

hg (kj / kg): Saturated Steam Enthalpy: 2783.4 kj / kg (Saturated Steam Enthalpy at 10 bar Pressure = https://en.viraisi.com/saturated-steam-table)

hf (kj / kg): Feed Water Enthalpy: 356 kj / kg (Suppose the feed water tank is held at 85 degrees: enthalpy of saturated water at 85 degrees)

m (kg / h): Amount of Feed Water: 12.000 kg / h

Q = 12,000 (2783.4 - 356)

Q = 29.128.800 kj

 

Fuel Amount = Heat for Steam Generation / (Fuel Lower Thermal Value * Boiler Efficiency)

Y: Fuel Amount

Q: Heat of Steam (29,128,800 kj in the previous process)

Hu: Fuel Lower Thermal Value (Natural Gas Lower Thermal Value: 8250 kcal / m ^ 3 = 34.518 kj / m ^ 3)

n: Boiler Efficiency (Suppose a natural gas boiler operating at 91% efficiency with 140 C flue gas temperature)

 

Y = 29.128.800 / (34.518 * 0.91)

Y = 927.33 m ^ 3 for 12 tons of natural gas

Y = 77.3 m ^ 3 / ton

 

According to Istanbul Natural Gas Distributor's statements dated 01.07.2019;

Eligible Consumers (300,001 -800,000 cubic meters) = 1.625624 TL / m ^ 3

77,3 * 1,625624 = 125,66 TL / ton = Fuel price for 1 ton of steam is 125,66 TL

 

In order to be able to find out the actual cost, it is necessary to add the cost of the personnel, which is used in the boiler room, the chemical cost used for water conditioning, the electrical cost, the maintenance cost, the water cost. This means roughly 25% to 30% more to the fuel price.