Albemarle using user variables scripts triggers

Proprietary Information of Albemarle Corporation.
Using User Variables,
Scripts & Triggers
Alan Kramer
Global FCC Modeling Specialist
KBC Software User Group Conference
2018
Houston

• Often we receive data with poor flue gas analysis.
• This leads to bad values for Hydrogen in Coke.
• For “simple” situations, we can use an equation to estimate the flue gas analysis to
give a reasonable H in Coke.
• For “complex” situations, we have to manually iterate each calibration case
individually for the flue gas estimate to give a reasonable H in Coke.
• We want to add H in Coke as an independent variable in calibration mode.
• We want the model to solve for the flue gas analysis.
The Problem
2

• Create a user variable to hold the H in Coke target value.
– This can be input from Calibration Input
• Create a user variable script to calculate the flue gas CO2.
• Use triggers to start the script calculation.
• Use triggers to iterate the CO2 calculation until the H in Coke target is met.
The Solution
3

Logic Schematic
4
Flue Gas CO2
H Content of Coke Stream
FCC

FCC-MeterFCC Coke-Meter
Logic Schematic
5
Flue Gas CO2
FCC

Logic Schematic
Flue Gas CO2
FCC
HinC Target

Creating User Variables To Store Values
7

Logic Schematic
HinC Script
Flue Gas CO2
FCC
HinC Target

Creating User Variables With Embedded Scripts
9
Type script here

Writing Scripts
11

VB Script Hints
12
• All script variables are variant type
• No script variable declarations
– You do need to declare arrays with dimensions
• If a variable in a script refers to an object, you must SET it
• No GOTO, GOSUB, EXIT or END
– Handle this with (nested) IF blocks and lots of planning
– But you can have multiple functions in a single script
• Empty = -32767

Logic Schematic
HinC TargetHinC Script
Flue Gas CO2
FCC

Writing Scripts
14

Writing Scripts
16

Logic Schematic
Flue Gas CO2
FCC
HinC Current Error

Writing Scripts
18

Logic Schematic
Flue Gas CO2
FCC
HinC Current ErrorIf ~0 then stop

Writing Scripts
20

Logic Schematic
Flue Gas CO2
FCC HinC Stored Error
HinC Current Error

Writing Scripts
22

Logic Schematic
Flue Gas CO2 HinC Stored Error
FCC
HinC Current ErrorIf = then stop

Writing Scripts
24

Logic Schematic
FCC
HinC Current Error

Writing Scripts
26

Logic Schematic
FCC T

Setting Trigger to Solve Parent Object on Value Change
28

Logic Schematic
Flue Gas CO2 HinC Stored Error T
Trigger 3
FCC
Value

Run Script After Parent Object Execute
32

Logic Schematic
Trigger 3 T
FCC

Logic Schematic
Trigger 1
Trigger 3 T
FCC
Value

35

Logic Schematic
Trigger 1 T
Trigger 3 T
FCC

Logic Schematic
37
Trigger 1 T
H Content of Coke Stream Trigger 2 T
Trigger 3 T
FCC
Compare
If different take on a random value
between 0 and 1

Setting Trigger to Take on A Radom Value
38

Logic Schematic
39
Trigger 1 T
H Content of Coke Stream Trigger 2 T
Trigger 3 T
FCC

Logic Schematic
40
Trigger 1 T
Trigger on Calib Start TH Content of Coke Stream Trigger 2 T
Trigger 3 T
FCC

Setting Trigger to Run Script on Calibration Starting
41

Logic Schematic
42
Trigger 1 T
Trigger 3 T
FCC
-1

43

Logic Schematic
44
Trigger 1 T
Trigger 3 T
FCC

• User variables and scripts aren’t really difficult or scary.
• You can use user variables and scripts to add important functionality.
• The ‘simplicity’ of VB Script has advantages and drawbacks.
• Triggers take some practice and patience to set up correctly.
• Save often. It’s easy to create infinite calculation loops.
• VB Script syntax examples on following slides.
Conclusions
45

• Create a variable referencing an object in the flowsheet
Set CokeMeter = SimulationCase.GetObjectInCase("FCC Coke-Meter")
• Create a variable referencing a variable in a meter
Set HinCVariable = CokeMeter.ActiveDataSet.Variables.Find("Hydrogen Content", "")
• Store the value from the ‘screened’ column of a meter using a specific unit of
measure
HinC = HinCVariable.ScreenedValueWithUnits("wt %")
• Put a value into the ‘input’ column of a meter
HinCVariable.InputValue = 7
VB Script Syntax Examples
46

• Get a user variable value from the same parent object
ThisScriptVariable = Me.GetUserVariable(“OtherUserVar").Variable.Value
• To set the value of a user variable value, flip the above statement around
• Get a user variable value with a specific UOM from another object (cokemeter)
ThisScriptVariable = CokeMeter.GetUserVariable(“OtherUserVar").Variable.GetValue(“UOM”)
• Set the value of the current user variable to xxx
Result = xxx
• Send something to the trace window
Application.Trace “Something = " & Something, True
VB Script Syntax Examples
47

Albemarle using user variables scripts triggers

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