Consultation about DPI and TDC in cellulosic_ethanol model

[zasddsgg]

Hello. When calling TEA result of cellulosic_ethanol model, DPI and TDC appear to return the same result, but according to the source code, https://github.com/BioSTEAMDevelopmentGroup/Bioindustrial-Park/blob/master/biorefineries/tea/cellulosic_ethanol_tea.py#L140-L141, TDC seems to be higher than DPI (it should be DPI plus depreciable indirect costs equals TDC), may I ask you is there anything wrong with this?

Besides, If I want to view DPI and TDC result, is it through the code tea._DPI(tea.installed_equipment_cost) and tea._TDC(tea._DPI(tea.installed_equipment_cost))?

In addition, since DPI and TDC are both 221.96 MM$, the value of Depreciable capital in Cash flow in excel is also calculated using 221.96 (DPI). However, according to C_D[:start] = TDC* self__construction_schedule in the source code in https://biosteam.readthedocs.io/en/latest/_modules/biosteam/_tea.html#TEA, the Depreciable capital should be obtained through TDC, so the current Depreciable capital seems to be considered small.

Thanks for your help. Wish you a good day.

The code is as follows: I use BioSTEAM 2.38.3, biorefineries 2.26.2

from biorefineries import cellulosic
import biosteam as bst
from biorefineries.tea import create_cellulosic_ethanol_tea
cs = cellulosic.Biorefinery('corn stover ethanol')
tea=create_cellulosic_ethanol_tea(cs.cornstover_sys)
print(tea._DPI(tea.installed_equipment_cost)/1000000)
print(tea._TDC(tea._DPI(tea.installed_equipment_cost))/1000000)

The screenshot is as follows:

[yoelcortes]

Thanks for splitting the issues, this is very helpful, @zasddsgg. I'll find some time tomorrow to help you for this question.

[yoelcortes]

@zasddsgg,

Thank you posting this issue. Maybe there was a bug in your version so that the TDC is smaller than what it should be. With biosteam 2.43.1 I get following:

• The codes you wrote work, but you can also use the TDC and DPI properties:

  from biorefineries import cellulosic
  import biosteam as bst
  from biorefineries.tea import create_cellulosic_ethanol_tea
  cs = cellulosic.Biorefinery('corn stover ethanol')
  tea=create_cellulosic_ethanol_tea(cs.cornstover_sys)
  print(tea.DPI / 1e6, tea._DPI(tea.installed_equipment_cost) /1e6) # -> 222.44, 222.44
  print(tea.TDC / 1e6, tea._TDC(tea._DPI(tea.installed_equipment_cost)) /1e6) # -> 333.66, 333.66

• The TDC is the total depreciable capital and it is used to generate the table:

Thanks,

[zasddsgg]

I got it. Thanks for your help again.