Convergence tolerances are used to define the maximum allowable errors in the various column equations for converged solutions. Only those convergence tolerance items applicable to the Column Algorithms selected in the Column Main Window are available.
Enter the tolerance in the appropriate data entry field, replacing the default value.
Bubble point error tolerance for each tray, i.e., the difference in the sum of the component liquid mole fractions times the component equilibrium K values and unity (perfect equilibrium).
Maximum allowable heat balance error for each tray. A tolerance of 0.001 is equivalent to a 0.1 degrees F error in the tray heat balance.
Equilibrium K value (Inside-Out and Enhanced I/O only)
Maximum allowable relative error for each component K value generated in the outer loop versus the value last used in the inner loop.
Component Balance (Not available with Inside-Out or Enhanced I/O algorithm)
Maximum allowable relative error in the material balance for every component on every tray of the column.
Except in rare instances, the Convergence Tolerances should not be changed from the default values. Relaxing these tolerances will seldom, if ever, result in resolution of a column convergence failure.
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