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.
1. Steam pressure
2. Steam temperature
3. GCV of fuel
4. Price of fuel
5. 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 ⴖb= 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 ⴖb)
=
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
Boiler efficiency ⴖb= 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 ⴖb)
=
670 X 2400 / (2800 X 0.65)
=
883.51 rupees / MT of steam or Rs 0.88 / kg of steam
Steam Cost Calculator
Note: This tool estimates steam energy and cost based on simplified enthalpy equations. It does not consider feedwater temperature or full steam tables.

No comments:
Post a Comment
Hi all,
This article is written based on practical experience..If liked, share with others, or any suggestions leave in comment box.