**In power
plant, calculation of cost of steam is very vital in commercial point of view.
Following are the parameters which affect the cost of steam.**

- Steam pressure
- Steam temperature
- GCV of fuel
- Price of fuel
- And Boiler efficiency

Following gives you the relation among steam cost & above
all parameters & vice versa

- Steam cost increases as the enthalpy or heat content in steam increases and vice versa
- Steam cost increases as the GCV of fuel decreases and vice versa
- Steam cost increases as the fuel price increases & vice versa
- Steam cost increases as the Boiler efficiency decreases & vice versa

**Understanding with
examples.**

**1.Calculate the cost of steam per kg, which is
been using for Steam turbine having pressure 121 kg/cm2 & temperature 550
deg C.The boiler of efficiency 75% uses coal of GCV 4200 kcal/kg to produce
this steam.Cosnsider the price of coal is Rs 5000/MT**

Enthalpy of steam at above pressure & temperature H = 830.43
kcal/kg

Boiler efficiency ⴖ_{b}= 75%

GCV of coal = 4200 kcal/kg

Now, cost of steam = Heat content in steam in kcal/kg X Fuel price / (GCV of fuel in kcal/kg X
Boiler efficiency ⴖ_{b})

= 830.43
X 5000 / (4500 X 0.75)

= 1230.26 rupees / MT of steam or Rs 1.23 / kg
of steam

** 2.Calculate
the cost of steam per kg, which is been using for chemical process plant having
pressure 5 kg/cm2 & temperature 180 deg C.The boiler of efficiency 65% uses
biomass of GCV 2800 kcal/kg to produce this steam.Cosnsider the price of biomass
is Rs 2400/MT**

Enthalpy of steam at above pressure & temperature H = 670
kcal/kg

Boiler efficiency ⴖ_{b}= 65%

GCV of coal = 2800 kcal/kg

Now, cost of steam = Heat content in steam in kcal/kg X Fuel
price / (GCV of fuel in kcal/kg X Boiler efficiency ⴖ_{b})

= 670 X
2400 / (2800 X 0.65)

= 883.51 rupees / MT of steam or Rs 0.88 / kg
of steam

**3. Calculate the cost of saturated steam given
to sugar process for juice boiling plant having
pressure 1.5 kg/cm2 & temperature 130 deg C.The boiler of efficiency 68%
uses bagasse (biomass) of GCV 2200 kcal/kg to produce this steam.Cosnsider the
price of biomass is Rs 2500/MT**

Enthalpy of steam at above pressure & temperature H = 650
kcal/kg

Boiler efficiency ⴖ_{b}= 68%

GCV of coal = 2200 kcal/kg

Now, cost of steam = Heat content in steam in kcal/kg X Fuel
price / (GCV of fuel in kcal/kg X Boiler efficiency ⴖ_{b})

= 650 X
2500 / (2200 X 0.68)

= 1086.22 rupees / MT of steam or Rs 1.086 /
kg of steam

** ****Deaeartor & HP heaters steam consumption calculations**