What can I do with EFFECTS?

Models

As a comprehensive consequence modelling tool, EFFECTS provides various models aimed at predicting the different phenomena that may occur after the release of a hazardous chemical including:

• Release

• Fire

• Dispersion

• Explosion

Release models

EFFECTS offers specialised models to predict outflow rate, leak duration, and exit conditions for different "Loss of Containment" situations. These models cater to gases, liquids, pressurised liquefied gases and batteries.

The release models include the following situations:

• Instantaneous releases (due to equipment’s catastrophic rupture).

• Continuous releases through a hole in equipment.

• Continuous releases from pipelines connected to a vessel.

• Continuous releases at a fixed flow rate.

• Releases from long pipelines.

• Li-Ion battery storage thermal runaway

• Tank overfilling generates flammable liquid cascades.

The liquefied gas release models include a spray release mechanism to predict flashing, jet expansion, the amount of liquid droplets that remain airborne, and potential liquid rain-out.

The liquefied gas release from the long pipeline model supports a crater formation from buried pipelined, accounting for additional dilution with air and reduced momentum in the vertical direction.

A separate pool evaporation model calculates the evaporated mass from a liquid spill (for both pure liquid releases or pressurised liquefied gas releases that suffer from rain-out).

Fire models

Depending on the release type (instantaneous or semi-continuous), different fire scenarios can be modelled. All fire models produce heat radiation and corresponding heat radiation damage (lethality) contours. The following fire models are available in EFFECTS:

• BLEVE Fireball: To assess the impact of a fire caused by the direct ignition of the catastrophic rupture of a vessel storing a pressurised liquefied gas or superheated flammable liquid.

• Gas Fireball: To assess the impact of a fire caused by the direct ignition of the catastrophic rupture of a vessel storing a pressurised gas.

• Jet Fire: To assess the impact of high-velocity jet flames resulting from pressurised gas or liquefied gas releases.

• Pool Fire: To analyse the heat radiation and flame characteristics from burning liquid pools.

• (Toxic) Combustion Products: To predict the formation rate of combustion products generated due to warehouse or pool fires.

Dispersion models

Once released into the air, wind and meteorological conditions determine how quickly a gas cloud will dilute and the distance to specific threshold concentrations. EFFECTS uses three main dispersion modelling approaches:

• Dispersion Model:

  • To assess the trajectory of clouds based on factors like temperature, velocity, liquid fraction, and density, with adaptations enabling automatic dispersion behaviour detection for heavy, neutral, and lighter-than-air gas behaviour.

  • The dispersion model can predict concentrations versus distance and time, size, trajectory and the amount of flammable mass in the cloud.

  • The model can also derive toxic dosages, which are translated into lethality levels using available Probit functions.

  • The model uses three main dispersion modelling approaches monitoring concentration, flammable mass or toxic dose.

• Neutral Gas Model: Simplified model assuming ideal gas behaviour, neglecting buoyancy and heavy gas effects. The model is most suitable for passive situations.

• Plume Rise from Fires: Predicts the plume path and resulting concentration contours, linked to the "Combustion Products" fire model.

Explosion models

Predict the overpressure and pressure impulse generated by various types of explosions:

• Solid Explosions: To assess the impact of the detonation of solids based on the TNT Methodology.

• Vapour Cloud Explosion: To assess the impact of VCEs using the TNO Multi-Energy model or GAME overpressure method for the definition of 3D congestion areas.

• Ruptures of Vessels: To assess the impact of failing pressure vessels, due to various mechanisms such as an "Internal explosion", "Runaway reaction" and "Ideal gas vessel burst". The model also assesses the impact of projected fragments.

• BLEVE and Gas Blast: To assess the overpressure effects of the catastrophic rupture of equipment storing pressurised non-flammable substances such as carbon dioxide, steam/water, etc. The difference between the BLEVE and Gas mode is due to the physical state of the released materials.

Damage models

Specific heat, overpressure or concentration levels can be translated into corresponding damage to humans or constructions. Damage relations are incorporated within all fire, explosion and dispersion models, although additional damage models are available as ad-hoc.

• Thermal and Overpressure Damage: Predict damage to structures and individuals based on thermal radiation and overpressure impacts.

• Toxicological Impact: Assess the fatality from toxic exposures.

Combined Loss of Containment model

A comprehensive model that calculates all possible phenomena to occur given certain process conditions. It links subsequent events and combines these sources, streamlining the automatic evaluation of loss-of-containment events.

Validation and documentation

Validation reports and theoretical background documents for the various models are available in EFFECTS & RISKCURVES Downloads Centre.

By utilising EFFECTS, safety professionals can thoroughly assess the consequences of hazardous chemical releases, ensuring accurate and reliable risk management.