- •Contents
- •1 An introduction to Phast
- •What to Expect of this Tutorial
- •Starting the program running
- •The main window
- •Opening the Phast example file
- •The Study Tree pane
- •The Models tab section
- •Level 1: the Workspace
- •Level 2: the Study
- •Level 3: the Equipment item
- •Level 4: the Scenario
- •The Weather tab section
- •The Parameters tab section
- •The Materials tab section
- •Pure Components
- •Mixtures
- •Warehouse Materials
- •The Map tab section
- •Bund types
- •Terrain types
- •Building types and Buildings
- •Raster Image Set
- •Viewing input data
- •The input dialog for the Chlorine tank Equipment item
- •The Grid View allows you to work on input data for multiple items
- •Running the calculations and viewing the results
- •Viewing the graphs for the LPG sphere Scenarios
- •Viewing results on the GIS, against the background of map images
- •Viewing the Reports for the Catastrophic rupture Scenario
- •Summary group: Consequence Summary Report
- •Input group: Input Report
- •Equipment group: Discharge Report
- •Equipment group: Dispersion Report
- •Equipment group: Commentary Report
- •Equipment group: Averaging Times Report
- •Equipment group: Dynamic Fireball Report
- •Equipment group: Explosion Report
- •Viewing the results for other types of Scenario
- •The Standalone flammable Scenarios
- •The Standalone explosion Scenarios
- •2 Setting up your own analysis
- •The form of the analysis
- •The Equipment and Scenarios defined in the analysis
- •Creating a new workspace
- •Saving the workspace
- •The contents of a new workspace
- •Setting up the map image
- •Inserting the raster image
- •Ensure that there is a Raster Image Set in the Map tab section
- •Insert a Raster Image inside the Set
- •Placing the image in the GIS Input View
- •Setting the co-ordinates and size of the image
- •The location of the site on the map
- •3 Performing the consequence analysis
- •Making sure the Run mode is set to Consequence
- •Defining the pressure vessel that contains a toxic material
- •Turn on the option to insert Equipment on the GIS
- •Insert a Pressure Vessel Equipment item
- •Setting the input data for the vessel
- •The Material tab section
- •The Toxic parameters tab section
- •The Geometry tab section
- •A Summary of the Input Data
- •Defining a catastrophic rupture scenario
- •Inserting the Scenario
- •Setting the input data
- •Elevation in Scenario tab section
- •Toxic parameters tab section
- •Run the calculations for the Scenario and view the results
- •Viewing the set of Graphs
- •Viewing outdoor toxic lethality results against the map
- •Defining the second scenario: a liquid release from pipework
- •Insert a Time varying short pipe Scenario
- •Supplying the tank shape data for the Pressure Vessel
- •Setting the input data for the Scenario
- •Scenario tab section
- •Material tab section
- •Short pipe tab section
- •Time varying releases tab section
- •Running the discharge calculations
- •Using the averaged discharge results to create a User-defined source Scenario
- •Inserting a Short pipe Scenario and set up the equivalent input data
- •Run the consequence calculations for the Short pipe and view the results
- •Defining the third scenario: toxic vapour from pipework
- •Defining three flammable releases
- •Setting the input data for the propane Equipment item
- •Copying the Equipment item
- •Changing the Material selection
- •Changing the coordinates
- •Setting the input data for the fire modelling
- •Running the consequence calculations and viewing the results
- •Jet Fire Graphs
- •Pool Fire Graphs
- •Fireball Graphs
- •Explosion Graphs
- •Flash Fire Graph
- •Alternative methods for modelling explosions
- •Creating a Folder and Scenarios for the other methods
- •Setting the inputs for the TNT explosion method
- •Setting the inputs for the Multi-Energy explosion method
- •Setting the inputs for the Baker-Strehlow-Tang explosion method
- •Running the calculations and viewing the results
- •Flammable releases from a rail tank wagon
- •Defining a folder and creating the Equipment data node for the wagon
- •Setting the Elevation for the Rupture Scenarios
- •Defining the Leak from the liquid side of the wagon
- •Defining the Fireball Failure under Flame Impingement
- •Defining a Standalones Equipment item
- •Defining a Fireball Scenario
- •Running the calculations and viewing the results
- •Saving the workspace
- •What next?
Running the consequence calculations and viewing the results
Select the Propane Equipment node and run the calculations for all three Scenarios.
You can view the results for all three Scenarios at the same time, as long as you view the results for the same single Weather for all Scenarios. To do this, move to the Weathers tab of the Study Tree, select the Category 1.5/F Weather, and then click on the Graphs option in the Home tab of the Ribbon Bar.
In the Results selection dialog that appears, check the box next to the Propane Equipment item to select all of the propane Scenarios for plotting, click on the right arrow to move the items to the Selected items list, and then click Finish to view the Graphs.
The Graph View will contains tab sections for Concentration graphs, as with the toxic Models, but it will contain Jet fire, Fireball, Pool Fire, Explosions and Flash Fire tab sections instead of the Toxic tab section.
The main features of the graphs are described below.
Jet Fire Graphs
The Jet Fire tab section contains three graphs, which are presenting results for the two pipework failures. The first graph shows radiation level versus distance, the second shows Intensity Radii to the lowest of the three default radiation levels set in the input data (4 kW/m2), and the third graph shows Lethality Radii to a lethality level of 1%, which is the lowest of the five lethality levels that you set. The maximum downwind effect distance shown in these graphs is around 34 m, which is the distance for 4 kW/m2 for the liquid line rupture release.
If a given Fire Radii graph is showing results for more than one Scenario or more than one Weather, then it will initially only be displaying results for a single level, which will be the lowest level set for that type of result (e.g. the lowest intensity level, or the lowest lethality level). This is different from a graph for a single Scenario and Weather, which will initially always display results for all available levels.
To see results for additional Fire Radii levels, click on Series… in the Configuration tab of the Ribbon Bar to open the Edit Series Properties dialog as shown. This dialog lists each of the available level-results for each Scenario, and you can check the boxes for additional levels to include them in the graph.
Pool Fire Graphs
There are two sets of Pool Fire Graphs: a set for the early pool fire, which is modelled for a continuous release only and occurs at the beginning of the release, at the time when the spill rate into the pool equals the fire burn rate, and a set for the late pool fire, which occurs at a time when the pool has reached its maximum radius. Each set contains three graphs, as with the jet fire graphs.
The early pool fire graphs are showing results the liquid line rupture release, as this is the only continuous Scenario that gives rainout, and this means that the two Radii graphs will initially be showing the results for more than one level. The maximum downwind effect distance is about 16 m, to a radiation level of 4 kW/m2 for late pool fire, and the distance to a.lethality level of 1% is about 13 m. The late pool fire graphs show results for both the liquid line rupture and the catastrophic rupture, so they initially show results for only one level.
| PHAST | April 2018 | www.dnvgl.com/software |
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