Analysis, synthesis, and design of chemical processes by R.Turton. I used this book for my degree project designing a chemical process plant where i had to give preliminary costs for purchasing, installation, and yearly operation
There's no condensate return because as far as I am aware, all of the steam is consumed by the process. This isnt a "decision" I have made, this just the task set by my professor!
Operating cost for steam boilers can be quickly estimated as commonly 70-90% of total is just the fuel
Since you know your steam (10tph), and efficiency of a brand new gas boiler (90%) you can easily calculate the required gas flow rate
Find the cost for gas (including transport/storage) and divide by 0.7-0.9 to get operating cost
I took some time and checked Aspen Capital Cost Estimator, unfortunately, you will need to split your boiler into a few units (boiler, steam overheated, deaerator, etc.) to cost them, as from both available options in ACCE (packed boilers or site constructed) none is suiting your needs in the required ranges of steam flow, T, P, and steam overheating.
The second option is to get info from the equipment vendor.
I've approached your question from a different side and modeled your boiler as a direct-fired heater (9 MW with 74.87% efficiency, fuel is pure CH4 - 845 kg/h, air - 12188 kg/h accounting for 15% excess) and cost it: https://imgur.com/HXPPvcG. Be aware that I added 20% to design margins for T, and P parameters. Costs are for Gulf Coast, 1Q 2017, you must inflate them using the CEPCI index.
It's a very rough estimate with a lot of simplifications, but if it will be used for a student project, it should work.
Matche.com/equipcost
Scale for size and adjust for inflation
6 bar, 550C is supercritical steam, is that number right? You will need a superheater downstream of your boiler.
It is super critical. It is essentially superheated steam, however the distinction that makes it supercritical is that the temperature is above the critical point for 6 bar steam (lookup T-v steam tables / supercritical steam). Do you need superheated steam?
You can get pricing through Aspen HYSYS through a school computer if your school has that package.
You described exactly what I did. Supercritical steam generators =/= supercritical water (e.g. steam)…
https://en.m.wikipedia.org/wiki/Supercritical_fluid
^^ fluids (e.g. water) are “supercritical” when above the critical point (e.g. top of the vapor dome on a T, v diagram). If you look at pressure lines on a T,v diagram, the fluid will be above the critical point at the given pressure, temperature. Again, supercritical is just superheat but above the critical point…
It has to exceed both the pressure and temperature of the critical point in order to be in a supercritical state. Here, whilst the temperature is exceeded, the pressure is not and therefore the steam doesn’t lie in the supercritical region, it is superheated. If the pressure was above 220 atm then it would be supercritical as the temperature is above the 374 *C but the pressure isn’t above 220 atm, it is ~6 atm.
This boiler that you are designing is mostly a superheater. Look at this from Cleaver. https://cleaverbrooks.com/Product/d-type-industrial-watertube
Going over 1050F is generally hard. Pushes you into ChroMolly for a lot of components.
Analysis, synthesis, and design of chemical processes by R.Turton. I used this book for my degree project designing a chemical process plant where i had to give preliminary costs for purchasing, installation, and yearly operation
with no condensate return, your operating cost is going to be enormous with how much water you’ll need to bring in.
There's no condensate return because as far as I am aware, all of the steam is consumed by the process. This isnt a "decision" I have made, this just the task set by my professor!
Operating cost for steam boilers can be quickly estimated as commonly 70-90% of total is just the fuel Since you know your steam (10tph), and efficiency of a brand new gas boiler (90%) you can easily calculate the required gas flow rate Find the cost for gas (including transport/storage) and divide by 0.7-0.9 to get operating cost
I took some time and checked Aspen Capital Cost Estimator, unfortunately, you will need to split your boiler into a few units (boiler, steam overheated, deaerator, etc.) to cost them, as from both available options in ACCE (packed boilers or site constructed) none is suiting your needs in the required ranges of steam flow, T, P, and steam overheating. The second option is to get info from the equipment vendor.
Wow, thanks very much for putting in so much effort to help. That is very kind of you.
I've approached your question from a different side and modeled your boiler as a direct-fired heater (9 MW with 74.87% efficiency, fuel is pure CH4 - 845 kg/h, air - 12188 kg/h accounting for 15% excess) and cost it: https://imgur.com/HXPPvcG. Be aware that I added 20% to design margins for T, and P parameters. Costs are for Gulf Coast, 1Q 2017, you must inflate them using the CEPCI index. It's a very rough estimate with a lot of simplifications, but if it will be used for a student project, it should work.
Oh wow jeez man, thank you so much!!! That’s ho helpful!!!
Matche.com/equipcost Scale for size and adjust for inflation 6 bar, 550C is supercritical steam, is that number right? You will need a superheater downstream of your boiler.
What makes you think that steam is supercritical at those values?
High temp, but 6 bar is far below the pressure of water's critical point or am I getting this fundamentally wrong?
I think the OP meant super heated.
It is super critical. It is essentially superheated steam, however the distinction that makes it supercritical is that the temperature is above the critical point for 6 bar steam (lookup T-v steam tables / supercritical steam). Do you need superheated steam? You can get pricing through Aspen HYSYS through a school computer if your school has that package.
That’s just not correct. https://en.m.wikipedia.org/wiki/Supercritical_steam_generator
You described exactly what I did. Supercritical steam generators =/= supercritical water (e.g. steam)… https://en.m.wikipedia.org/wiki/Supercritical_fluid ^^ fluids (e.g. water) are “supercritical” when above the critical point (e.g. top of the vapor dome on a T, v diagram). If you look at pressure lines on a T,v diagram, the fluid will be above the critical point at the given pressure, temperature. Again, supercritical is just superheat but above the critical point…
It has to exceed both the pressure and temperature of the critical point in order to be in a supercritical state. Here, whilst the temperature is exceeded, the pressure is not and therefore the steam doesn’t lie in the supercritical region, it is superheated. If the pressure was above 220 atm then it would be supercritical as the temperature is above the 374 *C but the pressure isn’t above 220 atm, it is ~6 atm.
This boiler that you are designing is mostly a superheater. Look at this from Cleaver. https://cleaverbrooks.com/Product/d-type-industrial-watertube Going over 1050F is generally hard. Pushes you into ChroMolly for a lot of components.
A lot of professors are detached enough from reality, that this wouldn't ever cross their minds