Set up base + delta model generator cases

Review the input data

When fitting existing Data Sets which already have results over the the range of conditions which require regression the existing data should be reviewed to determine the contained streams and properties of each stream.

Create a new case

To create a new case, click the New Case button and select Base + Delta Generation Case from the drop-down menu.

Enter case details

Enter a Name, Version and Description for the Case on the Details page. Also select a Refinery and a Model Type. Finally, select the basis for the case (weight/volume) from the drop-down menu and the default temperature unit for any entered temperature values.

If needed, modify the calorific value constants for Standard Refinery Fuel and Non-Liquid Fuel Equivalent, and edit their variable names.

Define the case topology

Define the flowscheme of the unit on the Topology > Schematic page. Drag the necessary units onto the Process Flow Diagram and connect their inlets and outlets. Enter names for the Process Flow Diagram streams and where relevant for each steam select the Material Type for the stream using the Stream Properties window.

Add any required user calculations

If any User Calculations are necessary, these can be defined on the User Calculations page.

Add input properties and operational parameters for the model

The properties used to define the feed are entered on the Inputs page. These properties are automatically added as columns to the Data Grid and change in output properties as a response to the change in these property values will be calculated.

Define the model outputs

The properties calculated by the model on the basis of input property values are included on the Outputs page. These properties are automatically added as rows to the Data Grid. During regression the calculated values of these output properties are used to determine the delta values which determine how much these properties change in response to changes in input feed property values.

Tips: If any Material Types are associated with particular Streams in the Topology, the properties included in the Material Type will be included in the Model Outputs. Several Material Types can be associated with any Stream in the Topology.

When clicking the Add Property button the previous stream/property pair entered is shown in the dialog. If entering the same property for several streams, select the property and then add it for each different stream as the list of properties is much larger to scroll through.

Set up the model bases

If the model requires more than one set of Base data these should be set up on the Multiple Bases page. Different bases are used to ensure the case can be linearised across the whole set of operating conditions. Each different base represents are different range of input properties. When using multiple bases a single variable must be defined which is used to switch between the different bases.

Add all data sets

When using existing data the number of Data Set should be configured to match the source of input data. When defining a base you must enter a Name. When using existing data the default options to use Default Base and Manual type should be used as you will manually enter the base data.

If Multiple Bases are defined each Base has an independent group of Data Sets and these must be configured in the Data Sets List.

Enter model data

Existing data can be copied and pasted from other software applications into the Data Grid. The Base data set is indicated with green shading.

Check the refression settings

Before regression check the Settings are correct. By default the fitted Base data may not exactly match the Base data as this may not be the most mathematically precise method. To ensure that the fitted data exactly matches the Base data select the Force Regression Through Base Values check box.

Select the Automatic Pruning check box if you want the Delta values below either of the given thresholds to be set to zero.

Perform regression

Click the Regress icon to regress the entered data and calculate the Base + Delta values.

Review the regression results

Review the model tags

Export the model data