Design Values »

The Design Values Node is used to specify the values and bounds for the key reactor design variables. The values entered here are fixed when doing a Simulation, or are considered as the initial point when optimizing the variables between the Lower and Upper Bounds.

When Enable Control Profiles is enabled, and when a variable (such as Temperature, Pressure, or any Flow) is selected in the Control Profiles node, the information in Design Values for that variable is overwritten with the information in the Control Profiles subnodes.

Specifications

This displays the list of reactor variables and their bounds for each case. It is stacked in tabs together with the the Initial Charge view.
The Specifications grid is organized as follows:

• The Case column displays the list of included cases in the Project.
  
• The Variable column depends on the characteristics and type of reactor selected in Reactor node. According to this, the variables are:
  
  Batch reactor:
  
  • Time
  • Temperature
  • Pressure (if phase behavior is single gas, or multiphase with a gas phase)
  • Catalyst Mass
  • Total Volume
  • Phases Volumes
  • Inflows
  • Outflows
  CSTR reactor: The variables below appear for each reactor:
  • Temperature
  • Pressure (if phase behavior is single gas or multiphase with a gas phase) or Phase Pressures for gas-gas
  • Total Volume or Reaction Phase Volume (if the reactor is a multiphase one)
  • Flows or Phases Flows (if the reactor is a multiphase one)
  • Catalyst Mass
  PFR reactor:
  
  • Temperature
  • Pressure (if phase behavior is single gas) or Phase Pressures (for gas-gas reactor)
  • Total Volume, Catalyst Mass or Phases Volume
  • Specific Membrane Area
  • Flows or Phase Flows
• The Lower column denotes the lower limit for the optimization of the design variable.
• The Value column denotes the initial value (actual value for simulation) for the design variable
• The Upper column denotes the upper limit for optimization of the design variable

Initial Charge

This view is stacked in tabs together with the Specifications view. As it is not shown by default, you may see it by clicking in the Initial Charge tab located at the bottom.
The view displays all included cases and the list of compounds for each case. Here, you may provide the bounds and starting points for the Initial Charge of each compound into the reactor. The initial charge is fixed to the Value entered when doing a simulation.
When Energy Balance is enabled in the Reactor node, Temperature also appears in this tab for each case. Temperature values and bounds correspond to the initial charge only. More information on the energy balance feature is provided in this example.



Description

The grid is designed similarly to its counterpart in the Estimation tree. Please see the corresponding help document.

Intermediate Feed

The grid is designed similarly to its counterpart in the Estimation tree, except the CSTR zones are called Process Units. Please see the corresponding help document.

Intermediate Separation

The grid is designed similarly to its counterpart in the Estimation tree, except the CSTR zones are called Process Units. Please see the corresponding help document.

Initialize Bounds
Initialize Bounds is used to fill automatically the bounds for the variables. It has two sub-actions:

Current Values
With this option you can autofill the minimum and maximum values with the current values.

By Percent of Current
This action is used to enter the bounds as percentage of the current values. On executing Initialize Bounds → By Percent of Current, a Parameters Dialog appears, requesting additional information:

1. Select the desired Case from the list. You may also select All Cases included.
   
2. Select the variable for which you want to initialize the bounds. You may also select All Variables.
   
3. Select the lower limit number and the upper limit number as a percentage of the current. The default values correspond to 90 and 110 % respectively.
   
4. Click OK, and the bounds will be filled.
   
   

Project Explorer

Optimization

Reactor

Case Design

Example Using Energy Balance