slide1
Download
Skip this Video
Download Presentation
Heuristics

Loading in 2 Seconds...

play fullscreen
1 / 23

Heuristics - PowerPoint PPT Presentation


  • 144 Views
  • Uploaded on

Heuristics. “Rules of Thumb”. Turton : Chapter 11. Use of Experience-Based Principles to:. Check new process designs Provide equipment size and performance estimates Help with troubleshooting problems with existing systems Verify computer simulations and results

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

PowerPoint Slideshow about ' Heuristics' - bina


An Image/Link below is provided (as is) to download presentation

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
slide1

Heuristics

“Rules of Thumb”

slide2

Turton: Chapter 11

Use of Experience-Based Principles to:

  • Check new process designs
  • Provide equipment size and performance estimates
  • Help with troubleshooting problems with existing systems
  • Verify computer simulations and results
  • Provide initial estimates for simulator inputs
  • Use as a starting place for initial designs
  • Developing preliminary process layouts
  • Turton indicates that heuristics:
  • Don’t guarantee a solution
  • May contradict other heuristics
  • Can reduce the time to solve problems
  • Depends on the context in which it is used
slide3

Example of Heuristic Usage

  • What is the density of water in SI units? In English units?
  • What does a gallon of milk weigh? What about 4 gallons of milk?
  • What does a cubic meter of air weigh?
  • The ratio of is approximately ____?
slide4

Creation of Heuristics / Shortcuts

  • Turton suggests a 3 step process:
    • Predict
    • Authenticate/Analyze
    • Reevaluate/Rethink:

Example: suppose you calculated a turbulent heat transfer coefficient inside

a 1.5” pipe as: , for water at 21OC and a velocity of 1.83 m/s.

Now, you need to estimate a heat transfer coefficient when the water temperature is 93OC and a velocity of 3.05 m/s.

Solution: assume still turbulent flow and that the viscosity and density of water may change significantly over this temperature range. So find appropriate equation for calculation of Nusselt number.

slide5

Creation of Heuristics / Shortcuts

Let subscript 1 be old, 2 be new T

slide6

Creation of Heuristics / Shortcuts

So for same diameter pipe; with water flowing; ignoring effects of T on

slide14

Example

Estimate size of flash drum V-102

slide17

Heuristics

“Rules of Thumb”

slide18

Example

Estimate size of heat exchanger E-105

slide21

In Class Exercise

Estimate size of reboiler E-106

  • Given:
  • mps (medium pressure steam) = 10 barg
  • T-101 operates at 3 bar
  • From simulation, reboiler duty = 2,512,500 W
slide23

Heuristics??

Homework: Problem 11.1 Turton

ad