Run Reconciliation without Range Constraints in Tanks

Run Reconciliation without Range Constraints in Tanks is a global option for running data reconciliation without acceptable range constraints in tanks. If this option is unchecked, AVEVA Production Accounting reconciles today’s inventory as balanced inventory of the tank when the imbalance of tank is smaller than the acceptable range.

The tolerance of tank inventory is normally zero and the reconciled inventory is equal to the measured inventory.

The tank cannot be balanced if all input and output streams are out of service or constant but if the imbalance of the tank is smaller than the acceptable range, the user wants to reconcile today’s inventory as balanced inventory.

Example

For example, input and output streams of "TankA" are out of service and the tolerance of "TankA" is zero (it means constant). The reconciled inventory is equal to measured inventory and therefore "TankA" is not balanced and the reconciled imbalance is 2 ton.

If you want to reconcile today’s inventory as balanced inventory (In this example, yesterday’s reconciled inventory = 100 ton), it is handled by the logic tag.

The below example shows that "TankA" is not balanced since "Input_ST1" and "Output_ST1" streams are out of service and the tolerance of "TankA" inventory is zero (it means constant) but inventory change (2 ton) of "TankA" is small and you want to set today’s inventory as yesterday’s reconciled inventory (100 ton) to make the balance of "TankA".

If so, the following logic tags are used to automatically reconcile today’s inventory as yesterday’s reconciled inventory.

The logic of "LG_TankA_bCorMass":

The logic of "LG_TankA_CorMassVolume":

The first logic sets the Boolean property of bCorMass as the result of the first logic and the second logic sets the corrected mass volume property as the result of the second logic.

With these logics, Corrected check box is checked and Corrected Inventory value is set as yesterday’s reconciled inventory value if the solvability of "Input_ST1" and "Output_ST1" streams is out of service (there are a few out of service status such as ‘OS’, ‘ROS’ and ‘COS’. See Flow Solvability for details.

And then reconcile it. The TankA is balanced because the corrected inventory is set as yesterday’s reconciled inventory.

As shown in the above example, you can reconcile today’s inventory as balanced inventory of the tank by using logic tags.

However, using logic tags is not easy. It is difficult to maintain them when the model configuration is changed. Also since logic tag uses the solvability of the related stream, it should be reconciled before using the logic tag.