How to solve the error of adding chemical reactions？

MFiX
#1

Hello，developers！
When I did the example of char combustion, there was an error, I can’t tick the energy equation,and I don’t quite understand the second half of this bug, So I wanted to ask how to solve this problem.

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Looking forward to any possible answer, thanks！

#2

I’d like to understand why you can’t click to enable energy equation.

Please go to the main menu, select “Submit bug report” and upload the resulting ZIP file so I can take a look. Thanks.

#3

co_2023-07-01T083008.449262.zip (29.3 KB)
This is my bug report, please check it out, thank you.

#4

Running this case, I am able to select energy equation from the “Model” pane.
I tried both version 21.4 (which I see you are using) and the current code.
Is the energy equation checkbox disabled? Did you reset the job? Can you send a screenshot showing the “Energy equation” control?

#5

Sorry，I can check the energy equation, but when I enable the energy equation, there is a problem with the picture, and the number of errors is rising rapidly.

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#6

There are several issues here, which we will address one at a time…

  1. The MFiX error popup should never be reporting thousands of errors, I think what is happening here is the same error is being printed for each particle, but MFiX should terminate after the first fatal error. So this looks like a little problem with MFiX.

  2. There are no solids species defined, so I think the check for the mass fractions summing to 1 should probably be skipped in this case.

  3. However, I see that you have diamond as a species in the fluid phase. Is this really what you intended?

  4. If I enable energy equations, and run with mfix version 21.4, I get the thousands of errors as you describe.
    But if I run a more recent MFiX version (23.1.1) with energy equations enabled, I get only one error:

Error from check_data/check_solids_common_all.f:379
Error 2010: There are no species defined for solids phase:  1
At least one species must be defined (needed to compute specific heat).

This points back to item (3) above - no species for the solids phase, where I think you intended to have C_cr_Diamond. You should also upgrade to the newest version of MFiX if possible because some of these issues with multiple messages have been resolved.

#7
  1. Check your initial and boundary conditions setup, the mass fractions specified are not reasonable.
#8

Thank you，I have diamond as a species in the solid phase.What is a reasonable mass fraction? Does the sum have to be 1? I modified the mass fractions of the bed, inlet and outlet and there was an error as long as the sum was not 1. And I don’t know how to determine the mass score, is this designed by myself?

#9

Species mass fractions for each phase must sum to 1: sum(IC_X_G)=1, sum(IC_X_S)=1)

Phase mass fractions for all phases must sum to 1. (IC_EP_G + IC_EP_S =1)

I can’t tell you what values to use, these are parameters of your model! But if your inlet only admits CO (as in the setup you posted) there is no O2 to react with the carbon.