Add utilities

Each process unit typically has a list of Utilities and Loss associated with it, such as heat, steam, and electricity.

For Base + Delta models, utilities are entered as predictions, and loss is modeled as an explicit product.

For other model types, such as distillation models, you can set the utility consumption/production on the Utilities and Loss page.

Tip: Filter the list via the Filter menu and configure which columns are shown, and in what order, via the View menu. See the Grids topic for more information.

To add a utility to your model:

1. Do either of the following:

   • Click Add Utility in the Utilities and Loss group of the Home ribbon tab.

   • Right-click anywhere on the table and choose Add > Utility from the context menu.

2. The Utility Editor dialog box opens (see next image). Enter the following information:

   • The Name of the utility.

   • The Value of the amount consumed or produced.

   • The Utility type (for example Fuel or Steam) and the corresponding unit of measure.

   • The Stream associated with the utility, and the corresponding unit of measure.

3. Click OK. The utility is added to the list.

   

To add a loss to your model:

4. Do either of the following:

   • Click Add Loss in the Utilities and Loss group of the Home ribbon tab.

   • Right-click anywhere on the table and choose Add > Loss from the context menu.

5. The Loss Editor dialog box opens (see next image). Enter the following information:

   • The Name of the loss.

   • The Value of the amount lost, and the corresponding unit of measure. Note that the loss is always expressed in weight-based units.

6. Click OK. The loss is added to the list.

To edit a utility or loss:

7. Select the utility or loss you want to edit.

8. Do either of the following:

   • Click Edit in the Utilities and Loss group of the Home ribbon tab.

   • Right-click anywhere on the table and choose Edit from the context menu.

9. Make your changes in either the Utility Editor or Loss Editor.

10. Click OK to confirm your changes.

Tip: You can also edit most values, such as Name and Value, directly in the table. Select a cell and start typing to replace the existing value.

To delete a utility or loss:

11. Select the utility or loss you want to delete.

12. Do either of the following:

    • Click Delete in the Utilities and Loss group of the Home ribbon tab.

    • Right-click anywhere on the table and choose Delete from the context menu.

13. Click Yes in the confirmation dialog. The selected utility or loss is removed from the table.

Utility base load

In the Utility Base Load page you can define the Base Load of each utility in your case. The base load is the minimum amount of that utility which is used without taking into account extra consumption from process units. For example, a plant has a minimum consumption of electricity for its general operation. As other process units operate, they may use or produce electricity depending on their operating parameters and feed, but the base load of electricity must still be satisfied. If the process units are not producing enough of a particular utility, it must be possible to purchase this utility by adding it to the Purchases > Utilities page.

To define a base load for a utility, enter a value in the Base Load column and select the correct unit of measure in the UoM column.

If a check box in the Active column is selected, Plan adds a constraint so that the amount of the corresponding utility is enough to satisfy the demand. If you clear the Active check box, the utility is not modeled. Any constraints including the utility are ignored, and the utility equations in any process models are not calculated. Any values for this utility in reports or in the Watch window are blank.

If a check box in the Enforce Balance column is selected, Plan adds a constraint to keep the corresponding utility balance as close to zero as possible, as opposed to just non-negative.

The first time you select a check box in the Enforce Balance column, if the corresponding check box in the Active column is not selected it becomes selected automatically.