Cost of steam generation

[bif]

I want to calculate the cost of raising steam from a natural gas fired boiler.

If I have mains uninterruptasble natural gas at say 2 pence per KWh and a boiler that is 80% efficient how do I calculate the cost of raising 10 barg saturated steam?

I think it will work out about £15 per te but I want to calculate it so I can adjust the gas price and change to steam cost.

I'm not interested in other costs at the minute, just the natural gas part of the cost

 

[rmw]

I'd love to help, but I never learned to think in quid; sorry.

rmw

 

[bif]

Its not the pounds I'm thining of.
I want to be able to work out how much btu's or kwh's are required to generate 10 barg steam. Then I can use this to work out a 'cost of steam generation'

 

[MJCronin]

bif....

A little more information is needed...

What assumption is to be made about the condensate return amount and temperature of the condensate feeding the boiler ?

If the boiler requires 100% makeup, then raising the temperature of 50F water to ~366F must be calculated.

If your system is new, and condensate is to be returned, the 190F condensate is a reasonable assumption.

Sample calculation:

To evaporate 212F water at 14.696 psia takes 970 BTU/lbm

Boiler Efficiency is ~.85; say natural gas is $5.00/mm BTU

Then: Evaporation Cost for 1 lb water is:

{(970)/(.85)}($5.00)/10000000 = $.0057

Or about $5.70 per 1000 lbs

Hope that this helps ?

-MJC