BREEZE Incident Analyst incorporates a suite of industry standard neutrally buoyant and dense toxic gas dispersion models to predict chemical concentration and flammability levels; thermal radiation fire models to predict radiation fluxes and temperature rise; and explosion models to predict blast force overpressures.
Incident Analyst includes:
What's New in Version 1.2
In addition to the technical capabilities of BREEZE Incident Analyst, the product is easy to use and quick to run. An intuitive interface guides the user through entering required and optional inputs associated with a potential chemical release (e.g. size and position of tank rupture, shape of storage tank, spill volume, and existence of an impoundment basin), and selecting the appropriate algorithms. Results are provided in both tabular and graphical formats including 2D contour, 3D volume, and time-series chart.
Toxic/Flamable Gas Dispersion Models
Fire (Thermal Radiation) and Explosion (Overpressure) Models
BREEZE Incident Analyst provides a wide range of dispersion models for analyzing accidental releases of toxic chemicals. The program is ideal for emergency response and planning as well as modeling accidental release scenarios for regulatory programs like the U.S. EPA's Risk Management Program (RMP).
DEGADIS is a dense gas dispersion model that estimates concentrations downwind from an accidental chemical release where the dispersing toxic or flammable substance is initially heavier than air.
SLAB is a dense-gas dispersion model used to estimate pollutant concentrations downwind from an accidental chemical release that is heavier than air.
INPUFF is a Gaussian puff model that simulates the atmospheric dispersion of neutrally buoyant or buoyant chemical releases. The model accounts for point sources and a release duration that is either finite or continuous.
AFTOX is a Gaussian puff/plume dispersion model that estimates concentrations downwind from accidental chemical releases where the dispersing plume has the same density as air.
Confined Pool Fire
Originally developed for the Gas Research Institute (GRI) and models a fire that occurs when liquid is ignited in a confined area such as a dike or a tank. The dike may be circular or rectangular. The model calculates the distance to various radiation levels specified by the user and also allows for the calculation of the dynamic temperature rise of a nearby target.
Unconfined Pool Fire
Developed for the GRI and models a fire that occurs when an unconfined spreading pool of liquefied fuel gas ignites. The model calculates the distance to various radiation levels specified by the user (e.g, the 5 kW/m2 level specified by the U.S. EPA in the 112(r) RMP regulations, or the radiant flux levels specified in the U.S. federal standard 49 CFR 193.2057 for LNG facilities) and calculates the radiation flux as a function of time at a given distance as the pool spreads.
Developed for the GRI and models a fire that may result from the leak or rupture of a pipeline containing a compressed or liquefied gas under pressure. The model calculates the distance to various radiation levels specified by the user and can calculate the dimensions of a high velocity jet flame ensuing from a ruptured pipeline.
If a quantity of flammable material is released, it will mix with the air and may result in a flammable vapor cloud. If this flammable vapor cloud finds an ignition source a vapor cloud explosion may result. Two main methodologies exist for modeling the explosion resulting from a vapor cloud explosion:
The explosion models include the following widely accepted approaches:
U.S. Army TNT Equivalency
Based on the work of the U.S. Army, this model uses a proportional relationship between the flammable mass in the cloud and an equivalent weight of TNT and assumes that the entire flammable mass is involved in the explosion and that the explosion is centered at a single location. The model uses one of two blast curves, depending upon whether the explosion being modeled is a surface burst or a free-air burst.
U.K. HSE TNT Equivalency
Based on the work of the U.K. Health and Safety Executive (HSE), this model uses a proportional relationship between the flammable mass in the cloud and an equivalent weight of TNT. It assumes that the entire flammable mass is involved in the explosion and that the explosion is centered at a single location.
This model treats the explosive potential of the vapor cloud as a corresponding number of equivalent fuel-air charges. The vapor cloud explosion is modeled as a series of sub-blasts with each sub-blast corresponding to a potential blast source within the cloud.
Based on the work of Baker and Strehlow, this model takes into account the variability of the blast strength by expressing the explosion as a number of fuel-air charges, each with individual characteristics.