CHE 185 – PROCESS CONTROL AND DYNAMICS

1 / 22

# CHE 185 – PROCESS CONTROL AND DYNAMICS - PowerPoint PPT Presentation

CHE 185 – PROCESS CONTROL AND DYNAMICS. State Space Models. Block Diagram Algebra. THE SEQUENCE OF SIGNAL PROCESSING IN A CONTROL LOOP CAN BE EXPRESSED IN BLOCK DIAGRAMS. BLOCK DIAGRAM ADVANTAGES EACH STEP IN THE PROCESS IS RETAINED AND CAN BE ADJUSTED INDEPENDENTLY

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.

## PowerPoint Slideshow about ' CHE 185 – PROCESS CONTROL AND DYNAMICS' - kedma

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

### CHE 185 – PROCESS CONTROL AND DYNAMICS

State Space Models

Block Diagram Algebra
• THE SEQUENCE OF SIGNAL PROCESSING IN A CONTROL LOOP CAN BE EXPRESSED IN BLOCK DIAGRAMS.
• EACH STEP IN THE PROCESS IS RETAINED AND CAN BE ADJUSTED INDEPENDENTLY
• CAUSE AND EFFECT RELATIONSHIPS FOR THE OVERALL SYSTEM ARE EASY TO ANALYZE
• THE IMPACT OF EACH COMPONENT IN tHE SYSTEM CAN BE CHECKED WHILE RETAINING A COMPREHENSIVE MODEL
System Algebra and Block Diagram
• Laplace transform – PARALLEL SYSTEM
• time-domain
• h(t) is the overall impulse response

http://fourier.eng.hmc.edu/e102/lectures/Laplace_Transform/node15.html

System Algebra and Block Diagram
• Laplace transform – Series combination
• time-domain
• h(t) is the overall impulse response

http://fourier.eng.hmc.edu/e102/lectures/Laplace_Transform/node15.html

System Algebra and Block Diagram
• Laplace transform – Feedback system
• time-domain
• h1(t) is the FORWARD PATH AND h2(t) IS FEEDBACK
• S-DOMAIN
• transfer function

http://fourier.eng.hmc.edu/e102/lectures/Laplace_Transform/node15.html

System Algebra and Block Diagram
• Laplace transform – Feedback system
• feedback could be either positive or negative
• FOR NEGATIVE
• TRANSFER FUNCTION

http://fourier.eng.hmc.edu/e102/lectures/Laplace_Transform/node15.html

EXAMPLE OF BLOCK DIAGRAM DEVELOPMENT
• DEVELOP THE RELATIONSHIPS BETWEEN CA2 AND CA0 FOR TWO STAGE CSTR SYSTEM WITH CONSTANT FLOWS, SAME VOLUME, AND REACTION RATE CONSTANT, k.
EXAMPLE OF BLOCK DIAGRAM DEVELOPMENT
• TRANSFER FUNCTIONS RELATING FLOWS IN AND OUT OF EACH UNIT:
• LINEAR COMPONENT MATERIAL BALANCES:
EXAMPLE OF BLOCK DIAGRAM DEVELOPMENT
• LaPLACE TRANSFORMS FOR MATERIAL bALANCES:
EXAMPLE OF BLOCK DIAGRAM DEVELOPMENT
• FROM THE FIRST OF THESE mass balance EQUATIONS:
• AND FROM THE SECOND EQUATION:
EXAMPLE OF BLOCK DIAGRAM DEVELOPMENT
• DEFINING TRANSFER FUNCTIONS FOR THE CONCENTRATIONS IN/OUT OF EACH REACTOR:

:

EXAMPLE OF BLOCK DIAGRAM DEVELOPMENT
• THE BLOCK DIAGRAM FOR THE PROCESS IS:

:

EXAMPLE OF BLOCK DIAGRAM DEVELOPMENT
• BLOCK DIAGRAM MATH::
• ALTERNATE DIAGRAM CAN BE DEVELOPED TO REPRESENT THE SAME OVERALL TRANSFER FUNCTION
EXAMPLE OF BLOCK DIAGRAM DEVELOPMENT
• ALTERNATE DIAGRAM CAN BE DEVELOPED TO REPRESENT THE SAME OVERALL TRANSFER FUNCTION
EXAMPLE OF BLOCK DIAGRAM DEVELOPMENT
• FORMAT FOR BLOCK DIAGRAMS
• Use of transfer function:
GENERAL SIGNAL RELATIONSHIPS
• (EX. 5-9), RIGGS
• Overall transfer function
• Which compares with the same function derived with laplace transforms in ex. 5-4
Block Diagram Algebra example
• Consider following block diagram:
In-Class Exercise: Block Diagram Algebra
• Develop overall transfer function for
In-Class Exercise: Block Diagram Algebra
• Develop overall transfer function for