Manage your assets

Add assets to your flowsheet

To add an asset to your plant's topology:

1. Go to the Flowsheet page.

2. Make sure the Toolbox pane is visible by clicking Toolbox in the Flowsheet group of the Home ribbon tab.

3. Select the asset you wish to add in the toolbox.

4. Drag the asset from the toolbox onto the flowsheet.

   

Use the Snap to Grid setting to automatically align your units to the layout grid when they are dropped or moved on the flowsheet.

Add units from process models

When you drag a process model to your flowsheet from the Toolbox pane, this creates a process unit with the same inputs and outputs as the process model. It may be necessary to edit the Stream Associations of the unit to make it match the plant, and use the Properties Inspector to change the number of inputs and outputs.

Warning: Consider the structure of the process model before adding it from the toolbox onto the flowsheet. The process unit is created with one pipe for every model output, which may not be desirable. For example, a model might have 25 outputs for each different product created. If the model were added to the flowsheet, a unit with 25 pipes would be created. It would be more efficient to add an empty process unit, add the model inside the unit, then join the model connections to the pipes manually.

The process models listed in the Toolbox pane depend on what is selected in the drop-down list at the top.

Choose an entry from the following categories:

• Model Library: Lists the currently open model.

• User Library: Lists any custom libraries of process models you have created (see below).

• Dynamic Library: Lists the shares you have access to which contain process models.

  Tip: Click the Name or Last Modified column header to sort entries in each category by name or date. Click again to reverse the sort order.

Note: Process models for distillation units do not appear in the Toolbox pane unless they have a description.
To see if a distillation process model has a description, check the Description column in the Process Models page, under the Reference Data tab of the Model Explorer.

Click the cog icon () to open the Process Model Library Manager dialog. In this dialog you can create custom libraries of process models. Click the arrow button to add process models to your custom library.

Tip: After adding a process model (and therefore process unit) to your flowsheet, it may be necessary to associate another process model with the same unit. For example, you may wish to add several process models to a single naphtha hydrotreater unit. See Process Units and Process Models for more information on adding more process models.

Connect assets

Once you have added assets to your flowsheet, you must connect them together:

5. Hover the mouse pointer over the exit pipe from one unit until the end of the pipe shows a small red circle.

6. Click the circle and drag the pipe to the input pipe of the unit where the stream is being sent. Alternatively, right-click and select Send to... from the context menu.

7. When the input pipe turns to another small red circle, release the mouse button to make the connection.

To disconnect pipes and units:

8. Place the mouse pointer over the small join in the pipe which connects the process units (this is close to the input unit) until the join is highlighted with a small red circle.

9. Either click the mouse and drag the circle to release the process units, or right-click the pipe between the process units and select Disconnect from the context menu.

Go to connected assets

To go from an asset to any connected asset, right-click on the asset and hover your mouse pointer on the Go To entry in the context menu. A list of connected assets appear, with the upstream assets listed first. Click on any asset in the list to center and select it on the flowsheet canvas.

The Go To entry does not appear when right-clicking on a pipe, since the Show Source and Show Destination entries already provide the same functionality.

Asset types

The following table lists the types of assets you can add to your flowsheet.

Rename assets, inputs and outputs

To rename any element on the flowsheet, including input and output sockets, either:

• Click the name of the element (not the element itself) on the flowsheet to select it, and type the new name.

• Click the element on the flowsheet to select it, and type a new name in the Properties window.

To avoid confusion, assets such as process units, manifolds, blenders and tanks should have unique names. However, it often makes sense to use the same name for several elements, such as the input and output sockets of a splitter or manifold, or a pipe and the socket it connects to. The following rules reduce the amount of manual renaming in these cases:

• When you have a splitter or a manifold with a single input, renaming the input automatically renames all the outputs with default names. Any outputs you have previously renamed are not changed.

  In the following image, renaming the Input socket to Renamed also renames Output 2 and Output 3, but leaves Custom Name unchanged because it has already been renamed.

  

• Connecting an output to an input socket automatically renames the input socket to match the output name, unless you have already renamed the input socket beforehand. Renaming the output after you have connected it to the input socket has the same effect.

  In the following image, the Water output of the process unit is connected to the Input socket of the manifold. The input is renamed to Water, as evidenced by the two outputs with default names also being renamed to Water.

  

• The previous two rules work together with multiple connected splitters and manifolds, allowing you to automatically rename sockets on multiple units. In the following image, renaming the first manifold input goes through the intermediate splitter and all the way to the second manifold outputs.

  

Change the number of inputs and outputs

To edit the number of inputs and outputs for a process unit:

10. Select the process unit by clicking on it on the flowsheet.

11. Type the new number of input and outputs in the Properties window.

Tip: Streams are always added to, and removed from, the bottom of the process unit. Therefore, when inserting or deleting streams onto a unit where names have already been entered for the streams, remember it may be necessary to rename some of the streams for the unit or move the pipes up or down the unit.
For example, a CDU may have 5 outputs where the bottom stream is named atmospheric residue. If the number of outputs is changed to 6 then the new stream will be inserted at the bottom. It will be necessary to use the Stream Associations dialog to reorder the output streams.

Tip: Most process units should only have one input. If different streams feed a process unit, these should be mixed before being directed into the process unit. The exception is for units such as hydrotreaters and alkylation units, which react two or more external components together, each of which arrives at the process unit separately.

To split a pipe into two or three streams, right-click on the pipe and choose either Split > 2 Streams or Split > 3 Streams from the context menu.

Manage stream properties

Streams must carry all required properties downstream. This means that a stream must have all the properties that are drivers in Base + Delta models the stream passes through, and the stream must also have all the properties required by the product blend specifications for any grade that stream is part of.

When a stream originates at a distillation model, the distillation model can automatically be updated to carry the necessary properties by clicking the Insert Upstream Properties button. This edits the distillation model to include the necessary properties.

So, for example, if a distillate hydrotreater requires a cetane index for all its feeds, then clicking the Insert Upstream Properties button will insert a cetane index as a prediction in the distillation model supplying the hydrotreater.

Note: Insert Upstream Properties has no effect on Base + Delta models. These must be manually edited by you.
For example, a reformer may require N+2A for the feed stream. Clicking Insert Upstream Properties does not affect the naphtha hydrotreater which supplies the reformer. This must be modified manually.

Warning: If you add a blender that contains post-blend correlations, these correlations are added to the assay table. This results in the addition of many unnecessary predictions to the outputs of crude units when you use the Insert Upstream Properties feature. To avoid this issue, whenever you add a blender, use the Insert Upstream Properties feature before adding any post-blend correlations.

Override stream properties

Click Override Property in the Flowsheet group of the Home ribbon tab to enter fixed override values for the selected stream. To override a particular stream property value:

12. Select the stream to override.

13. Click Override Property.

14. Make sure the correct stream and process unit are selected.

15. Select the property to override, either from the existing Modelled Properties list, or by selecting All Properties and choosing the property from the list (you can filter the list of properties).

16. Enter the new value for the property in the unit of measure selected for the property.

Overriding a stream property creates a new entry on the Overrides page. The override formula may be edited further here to allow it to be an offset or defined by another calculation.

When you click Optimize, your process units will be highlighted where they have exceeded any limits (based on the warning and error ranges entered for your constraints). Hover your mouse over the unit to see the diagnostic text, and review the messages in the Diagnostics window.

Group tanks

You can group your tanks into specific categories using Tank Types. Tank types often represent the tank services employed in plants where a group of tanks are often used together and associated with a particular operating mode.

You can add, delete and rename tank types in the Tank Types dialog box. To open the Tank Types dialog box, click Manage Tank Types in the Tanks group of the Home ribbon tab.

To add a new tank type, click Add and enter a name.

To rename a tank type, click the tank type name and enter the new name.

To remove a tank type:

17. Select the tank type to delete and click Remove. Click OK in the dialog to confirm deletion.

18. In the Tanks grid, re-associate each tank in this group with a new tank type.