Name , title of the presentation
description
Transcript of Name , title of the presentation
1
Name, title of the presentation
Master project: Control structure design for a sequence of distillation columns
Tor Anders MarvikSupervisor: Sigurd SkogestadCo-supervisors: Vladimoros L. Minasidis
Johannes Jäschke
2
Optimal control structure of two distillation colums in a sequence
Varying marked conditions
Computer model
Active constraint regions
Self-optimizing variablesRegion 1: V2, V1, xD2,B activeRegion 2: xD2,B active
General/systematic approach?
3
The model
Based on column A by Skogestad
41 trayFeed on tray 21Assumtions:
Constant pressureConstant relative volatility Constant molar flows, No vapor holdup, Equlibrium on all stagesTotal condenser
Steady state model in Matlab
Conditions from Jacobsen
4
5
Jacobsen’s map
6
V2, V1, xD2,B active
7
V2, V1, xD2,B active
8
Approach to find self-optimizing variables?
• Brute force• Null space HF=0• Exact local method
• Possible disturbances– F,q,zF, prices,
• CV candiates – Tray temparature, composition, L1, V1, D1, L2, V2 D2, B2– Combination
9
Brute force
10
11
Combinations as CV
• Combination of Temperature (As Roal Bræck Leer)– All stages
– Every 5th stage
• Ratio with feed flow
12
Size of the measurement error
• Temperature: 1 K• Consentraiton: 5%• Flow: 10%
13
To do
• A LOT
• Standard approach• Brute force exact local method
• See how L changes to disturbances when the candiadate CV is fixed
14
Thank you
Feedback and questions?