Material streams are flows of materials from one place in the flowsheet to another. Each material stream is associated with a stream type, and can therefore carry only a specific set of compounds. More over, streams have a temperature, a pressure, a phase composition and possibly a number of thermodynamic and/or physical properties.
Information streams represent a flow of information from one place in the flowsheet to another. The actual data on an information stream can vary, and is determined by the first port such a stream is connected to. COFE currently only supports a collection of scalar real data elements. You may not be able to connect the other end of an information stream to a unit operation's information port if the unit operation decides that the data that is available on the stream (resulting from connecting the first end of the stream) is not compatible with the data that is expected by the unit operation.
In COFE, in addition to information ports exposed by unit operations, you can add virtual information ports to a unit operation. Virtual information ports are connected to a real parameter value (or real element of an array parameter).
Energy streams are flow of heat duty from one place in the flowsheet to another. Energy streams are much like information streams, only the meaning (and names) of the information items transferred by the stream is pre-defined:
|work||the amount of energy that is transferred; must always be present||W|
|temperatureLow, temperatureHigh||the temperature range between which the energy is transferred||K|
|axisFrequency||the rotation frequency of an axis that is performing work||s-1|
Mind that inlet and outlet for an information port determines which unit operation is responsible for determining the amount of data. Positive work is provided by an outlet and consumed by an inlet; the outlet determines the amount of work. Negative work is provided by an inlet and consumed by an outlet; the outlet determines the amount of work.
Streams and unit operations
Streams can originate from a unit operation, or can be a feed stream. Streams can go to a unit operation, or can be a product stream.
To add a stream to your flowsheet, first select the stream type on the toolbar. Then, select Insert stream from the menu or the toolbar, or by pressing Ctrl+I. Click on the start position of the stream. Move your mouse to the end position of the stream and click again. A stream can be connected to unit operations at the time it is inserted.
To remove a stream from the flowsheet, select the stream and press Del on the keyboard, or select Delete from the Edit menu, or Delete from the menu that pops up when clicking with the right mouse button on the stream. Mind that all selected streams and unit operations will be deleted.
The route of a stream is automatically determined. You can however add and remove points to the route that you want the stream to follow. To add points to the route, right click on the stream. To remove a route point, right click on the route point.
An attempt will be made to make the route such that streams are overlapping as little as possible, and streams do not overlap with unit operations. The routes of streams are calculated in order in which they appear in the flowsheet. To change the order of a stream in the flowsheet, select the stream and select and item from the Stacking Order menu that appears when you click the right mouse button on the stream.
To set the properties for a stream, open the stream in the stream display. Hover your mouse over the stream to get more information on the stream and its content.
You can change the name of a stream by clicking the right mouse button on the stream and select Rename. If the name is displayed, you can also simply double click the name. The name of the stream will be displayed on the stream if the Stream Labels sub-menu of the View menu is ticked. The name is always displayed on top of the stream, by default in the centre of the stream's route. You can change the location of the name display by dragging the name, or right clicking and selecting Label Location.
Right click on a stream and select Comment to add or change a comment for a stream. Streams with comments will show an information icon. Hold your mouse over the icon to see the content of the comment.