introduction to screen3 smokestacks image from univ. of waterloo environmental sciences marti blad
TRANSCRIPT
![Page 1: Introduction to SCREEN3 smokestacks image from Univ. of Waterloo Environmental Sciences Marti Blad](https://reader030.vdocument.in/reader030/viewer/2022032517/56649cb15503460f94976503/html5/thumbnails/1.jpg)
Introduction to SCREEN3
smokestacks image from Univ. of Waterloo Environmental Sciences
Marti Blad
![Page 2: Introduction to SCREEN3 smokestacks image from Univ. of Waterloo Environmental Sciences Marti Blad](https://reader030.vdocument.in/reader030/viewer/2022032517/56649cb15503460f94976503/html5/thumbnails/2.jpg)
2
Historically
Image from collection of Pittsburgh Photographic Library, Carnegie Library of Pittsburgh
![Page 3: Introduction to SCREEN3 smokestacks image from Univ. of Waterloo Environmental Sciences Marti Blad](https://reader030.vdocument.in/reader030/viewer/2022032517/56649cb15503460f94976503/html5/thumbnails/3.jpg)
3
C(x,y,z) Downwind at (x,y,z) ?C(x,y,z) Downwind at (x,y,z) ?
Gaussian Dispersion
Dh
hH
z
x
y
¤ Dh = plume rise
h = stack height
H = effective stack heightH = h + Dh
![Page 4: Introduction to SCREEN3 smokestacks image from Univ. of Waterloo Environmental Sciences Marti Blad](https://reader030.vdocument.in/reader030/viewer/2022032517/56649cb15503460f94976503/html5/thumbnails/4.jpg)
4
SCREEN3 Model Assumptions Continuous pollutant emissions Conservation of mass in atmosphere Steady-state meteorological conditions Concentration profiles are represented by
Gaussian distribution—bell curve shape
![Page 5: Introduction to SCREEN3 smokestacks image from Univ. of Waterloo Environmental Sciences Marti Blad](https://reader030.vdocument.in/reader030/viewer/2022032517/56649cb15503460f94976503/html5/thumbnails/5.jpg)
5
SCREEN3 designed for… Single source, short-term calculations
Estimate maximum ground level concentrations
Distance to max. concentration from source Concentrations at user defined distances Simple downwash algorithm
Max. concentrations in near & far wake Estimate concentrations in cavity
recirculation zone Source types
All options for point & flare
![Page 6: Introduction to SCREEN3 smokestacks image from Univ. of Waterloo Environmental Sciences Marti Blad](https://reader030.vdocument.in/reader030/viewer/2022032517/56649cb15503460f94976503/html5/thumbnails/6.jpg)
6
SCREEN3 designed for…(cont.) Full range of meteorological conditions accepted
Stability classes Wind speeds Inversion break up Shoreline fumigation
Determine plume rise for flare releases Includes effects of BID
Buoyancy induced dispersion Simple area & volume sources
![Page 7: Introduction to SCREEN3 smokestacks image from Univ. of Waterloo Environmental Sciences Marti Blad](https://reader030.vdocument.in/reader030/viewer/2022032517/56649cb15503460f94976503/html5/thumbnails/7.jpg)
7
Source Options
![Page 8: Introduction to SCREEN3 smokestacks image from Univ. of Waterloo Environmental Sciences Marti Blad](https://reader030.vdocument.in/reader030/viewer/2022032517/56649cb15503460f94976503/html5/thumbnails/8.jpg)
8
Dispersion Model Structure
INPUT DATA: Operator experience
METEROLOGY EMISSIONS RECEPTORS
Model Output: Estimates of Concentrations at Receptors
Model does calculations
![Page 9: Introduction to SCREEN3 smokestacks image from Univ. of Waterloo Environmental Sciences Marti Blad](https://reader030.vdocument.in/reader030/viewer/2022032517/56649cb15503460f94976503/html5/thumbnails/9.jpg)
9
Model Input Considerations Source type
Point, area, volume, flare Stack or source emission data
Pollutant emission data Stack- or source-specific data Temperature in stack Velocity out of stack
Receptor data
![Page 10: Introduction to SCREEN3 smokestacks image from Univ. of Waterloo Environmental Sciences Marti Blad](https://reader030.vdocument.in/reader030/viewer/2022032517/56649cb15503460f94976503/html5/thumbnails/10.jpg)
10
Input screen 1
![Page 11: Introduction to SCREEN3 smokestacks image from Univ. of Waterloo Environmental Sciences Marti Blad](https://reader030.vdocument.in/reader030/viewer/2022032517/56649cb15503460f94976503/html5/thumbnails/11.jpg)
11
Input Considerations
Actual pattern of dispersion depends on atmospheric conditions prevailing during release
Major meteorological factors that influence dispersion of pollutants Atmospheric stability (& temperature) Mixing height Wind speed & direction
![Page 12: Introduction to SCREEN3 smokestacks image from Univ. of Waterloo Environmental Sciences Marti Blad](https://reader030.vdocument.in/reader030/viewer/2022032517/56649cb15503460f94976503/html5/thumbnails/12.jpg)
12
Meteorological inputs Appropriate meteorological
conditions Appropriate for location Appropriate for averaging time period Wind stability and speed
Flat terrain or complex terrain Distances to points of interest
Receptors
![Page 13: Introduction to SCREEN3 smokestacks image from Univ. of Waterloo Environmental Sciences Marti Blad](https://reader030.vdocument.in/reader030/viewer/2022032517/56649cb15503460f94976503/html5/thumbnails/13.jpg)
13
Input screen: met data
![Page 14: Introduction to SCREEN3 smokestacks image from Univ. of Waterloo Environmental Sciences Marti Blad](https://reader030.vdocument.in/reader030/viewer/2022032517/56649cb15503460f94976503/html5/thumbnails/14.jpg)
14
Discrete Distance input
![Page 15: Introduction to SCREEN3 smokestacks image from Univ. of Waterloo Environmental Sciences Marti Blad](https://reader030.vdocument.in/reader030/viewer/2022032517/56649cb15503460f94976503/html5/thumbnails/15.jpg)
15
Automated Distances input
![Page 16: Introduction to SCREEN3 smokestacks image from Univ. of Waterloo Environmental Sciences Marti Blad](https://reader030.vdocument.in/reader030/viewer/2022032517/56649cb15503460f94976503/html5/thumbnails/16.jpg)
16
Building downwash option
![Page 17: Introduction to SCREEN3 smokestacks image from Univ. of Waterloo Environmental Sciences Marti Blad](https://reader030.vdocument.in/reader030/viewer/2022032517/56649cb15503460f94976503/html5/thumbnails/17.jpg)
17
Run: screen update
![Page 18: Introduction to SCREEN3 smokestacks image from Univ. of Waterloo Environmental Sciences Marti Blad](https://reader030.vdocument.in/reader030/viewer/2022032517/56649cb15503460f94976503/html5/thumbnails/18.jpg)
18
View text results: editor
![Page 19: Introduction to SCREEN3 smokestacks image from Univ. of Waterloo Environmental Sciences Marti Blad](https://reader030.vdocument.in/reader030/viewer/2022032517/56649cb15503460f94976503/html5/thumbnails/19.jpg)
19
Model results: graphs
![Page 20: Introduction to SCREEN3 smokestacks image from Univ. of Waterloo Environmental Sciences Marti Blad](https://reader030.vdocument.in/reader030/viewer/2022032517/56649cb15503460f94976503/html5/thumbnails/20.jpg)
20
Evaluate graph
![Page 21: Introduction to SCREEN3 smokestacks image from Univ. of Waterloo Environmental Sciences Marti Blad](https://reader030.vdocument.in/reader030/viewer/2022032517/56649cb15503460f94976503/html5/thumbnails/21.jpg)
21
Shape of picture
![Page 22: Introduction to SCREEN3 smokestacks image from Univ. of Waterloo Environmental Sciences Marti Blad](https://reader030.vdocument.in/reader030/viewer/2022032517/56649cb15503460f94976503/html5/thumbnails/22.jpg)
22
Review Dispersion = expand & diffuse
Picture
Gaussian = even spreading directions Highest along axis
Input data quality critical Screen3 limitation for reactive chemicals
No reactions assumed to create or destroy
![Page 23: Introduction to SCREEN3 smokestacks image from Univ. of Waterloo Environmental Sciences Marti Blad](https://reader030.vdocument.in/reader030/viewer/2022032517/56649cb15503460f94976503/html5/thumbnails/23.jpg)
23
SCREEN3DEMONSTRATION
Software provided courtesy of
a division of Lakes Environmental Consultants Inc.