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Industrial plant mass balance calculation, input isn't output

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    Industrial plant mass balance calculation, input isn't output

    Hello,

    I want to ask the community to help me with a problem of a mass balance calculation of an industrial plant.

    I tried to find the error by tracing the precedent and dependent and by checking the formulas with the show the formula command.
    I have an input of 80 tonnes /h and get 80.0014 tonnes/h output. (See the red comments)
    I have a part of the plant, which is doubled or tripled, depending on the multiplicator "Anzahl der Linien". (Yes, thats german, I'm from Austria :-) )
    Here the multiplicator is 2.

    Does anybody know a sophisticated tool for searching for the error?
    I don't expect you to search for the error, because the file is very big.
    Yet, if anybody finds it, I won't complain ;-)

    By the way, I deleted sensitive data, so the values are not representative, but the calculation is valid, as with the real values.

    wirh regards and thanks for the help, Secundo
    Attached Files Attached Files

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    Re: Industrial plant mass balance calculation, input isn't output

    Probably binary decimals being added up.

    Extend the format of the values to 8 decimal places and you'll see the figures are not actually 2 decimal places.
    Regards
    Special-K

    Ensure you describe your problem clearly, I have little time available to solve these problems and do not appreciate numerous changes to them.

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    Re: Industrial plant mass balance calculation, input isn't output

    Hmm, I'm not quite sure what you mean.

    The decimals are all calculated very accurately, with the excel standard calculation accuracy. I counted 10 numbers after the dot.
    Or did you mean something else?

    I also have 100 iteration steps and a maximum change of 0.000000001.




    Quote Originally Posted by Special-K View Post
    Probably binary decimals being added up.

    Extend the format of the values to 8 decimal places and you'll see the figures are not actually 2 decimal places.

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    Re: Industrial plant mass balance calculation, input isn't output

    You're querying why 80 tonnes input doesnt match 80.0014 tonnes output.

    For a start QP17 is not 19.35 as displayed, it's 19.35064116 (at least)
    You have percentages elsewhere (for that, read division calculations with decimal results) that may not produce an exact result, for example 10/3 =3.33333 recurring.

    If you add up percentages they may not add up to the correct input because of the decimal results.

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    Re: Industrial plant mass balance calculation, input isn't output

    Excel normally calculates with 15 digits of precision, so the division calculations with decimal results shouldn't influence a number with 6 digits. (At least as I understand it)

    I also allow only change of digits after the tenth digit (maximum change of 0.000000001 in the menu options/formulas)

    I also extended the cells to 16 digits after the dot (for example QP37 with 19,3506411580123000), they are all just shown with less digits, in reality the numbers are exact to about 12 digits after the dot.

    Maybe I'm wrong, but if you know the fault in my reasoning, I would be happy if could show me.

    Thanks for your help, Special-K

    Quote Originally Posted by Special-K View Post
    You're querying why 80 tonnes input doesnt match 80.0014 tonnes output.

    For a start QP17 is not 19.35 as displayed, it's 19.35064116 (at least)
    You have percentages elsewhere (for that, read division calculations with decimal results) that may not produce an exact result, for example 10/3 =3.33333 recurring.

    If you add up percentages they may not add up to the correct input because of the decimal results.

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    After reading your comments once more, Special-K, I think I understand your point.
    As the input of my calculation doesn't match the output,
    it may really be the accumulated errors of the iteration, since the calculation runs through a lot of instances.
    Do you concur?


    Quote Originally Posted by secundo View Post
    Excel normally calculates with 15 digits of precision, so the division calculations with decimal results shouldn't influence a number with 6 digits. (At least as I understand it)

    I also allow only change of digits after the tenth digit (maximum change of 0.000000001 in the menu options/formulas)

    I also extended the cells to 16 digits after the dot (for example QP37 with 19,3506411580123000), they are all just shown with less digits, in reality the numbers are exact to about 12 digits after the dot.

    Maybe I'm wrong, but if you know the fault in my reasoning, I would be happy if could show me.

    Thanks for your help, Special-K

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