Enhancing Safety with CFD-Based Consequence Analysis

Computational Fluid Dynamics to predict hazards & increase protection in HSE engineering

CFD (Computational Fluid Dynamics) is a powerful tool to simulate and understand fluid behaviours, including gas and liquid flows. In the realm of Health, Safety, and Environment (HSE) engineering consultancy, CFD is an indispensable tool for accurately estimating hazards and simulating the consequences of chemical spills, gas cloud dispersion, jet fires, pool fires, and explosions. The use of CFD will bring multiple advantages for evaluating consequences:

1. Unmatched Accuracy: CFD provides highly precise estimates, ensuring that potential hazards are identified and quantified with exceptional accuracy.
2. In-Depth Insights: Gain a deeper understanding of threats, enabling more informed decision-making and strategic planning.
3. Enhanced Protection: CFD offers robust options to safeguard plant equipment and process facilities, minimising the risk of accidents and ensuring a safer working environment.

CFD Modeling Advances for Process Safety

Advanced Computational Fluid Dynamics (CFD) modeling techniques are transforming the landscape of process safety analysis. By simulating a wide range of hazardous scenarios, these tools provide critical insights for risk assessment and mitigation:

• Jet fire simulation: Accurately model jet fire behaviour, including flame length, temperature, and radiation intensity, to design effective protective measures.
• Gas dispersion modeling: Predict hazardous gas spread, identify exposure areas, and develop mitigation strategies and possible layout changes.
• Pool fire simulation: Simulate pool fires to assess the impact on surrounding structures and equipment.
• Gas explosion modeling: Accurately model gas explosions, including overpressure, blast effects, and structural damage, to support effective safety measures and structural design.
• Leakage scenarios for flammable liquids and gases forming explosive atmospheres (ATEX): CFD can accurately model the dispersion of leaked gases, simulating their movement and mixing with ambient air. This allows for the identification of areas where explosive concentrations may form, especially in ventilated indoor locations.

Video 1. Gas and Dust Explosion is solved in 3D CFD simulation

CFD's Role in Jet Fire Analysis to Enhance Process Safety

By utilising CFD modeling techniques, engineers can effectively identify potential hazards, evaluate the efficacy of existing safety measures, design new facilities with integrated safety features, ensure compliance with industry regulations, and ultimately minimise the risk of property damage, injuries, and fatalities.

CFD can be used to:

• Predict jet fire characteristics: Determine the flame length, temperature distribution, and radiation intensity of a jet fire.
• Assess the impact on surroundings: Evaluate the potential for heat transfer to nearby structures and equipment.
• Design protective measures: Optimise the placement of fire barriers, water curtains, and other safety devices.

Video 2. A Jet Fire Incident Analysis with CFD

CFD for Gas Dispersion and Fire Hazards: Addressing Critical Safety Issues

By utilising modeling techniques, engineers can effectively identify potential gas release points, ensure regulatory compliance, and minimise the environmental impact of gas dispersion. Gas dispersion refers to the spread of hazardous gases into the atmosphere, which can lead to a variety of consequences, including:

• Toxicity: Exposure to toxic gases can pose a serious threat to health.
• Flammability: Flammable gases can ignite, leading to devastating explosions or fires.
• Environmental impact: Uncontrolled gas dispersion can harm ecosystems and pollute water sources.

CFD's Capabilities in Gas Dispersion Modeling

Once HSE risks have been identified and assessed, CFD modeling offers a valuable tool for gaining deeper insights into potential hazards and developing effective mitigation strategies. By simulating gas dispersion scenarios, engineers can refine risk assessments and ensure that safety measures are tailored to the specific characteristics of the facility and its surroundings.

• Simulate gas release scenarios: Model the release of gases from various sources, such as leaks, vents, or explosions.
• Predict gas dispersion patterns: Determine the concentration of gases downwind and identify areas of potential exposure.
• Evaluate mitigation strategies: Assess the effectiveness of ventilation systems, emergency shutdown procedures, and other safety measures.

CFD and Fire Hazards

Fires pose significant risks to process plants, including property damage, injuries, and fatalities. Understanding the potential for fire hazards is crucial for ensuring the safety and operational efficiency of these facilities.

In addition to gas dispersion, CFD can also be used to simulate fire hazards, such as:

• Pool fires: Fires that occur on the surface of a liquid.
• Vapor cloud explosions: Explosions caused by the ignition of a flammable gas cloud.
• Thermal radiation effects: The impact of heat transfer from fires on people and structures.
• Identify potential fire sources: Pinpoint areas where fires may occur, such as equipment malfunctions or process upsets.
• Evaluate fire spread: Determine how fires may spread within the facility and to nearby structures.
• Assess the impact of thermal radiation: Understand the potential for heat transfer from fires to cause damage or ignite other materials.
• Develop effective fire protection systems: Design and optimise fire detection, suppression, and evacuation systems.
• Mitigate domino effects: Identify and address potential domino effects, such as the spread of fire to adjacent facilities or the release of hazardous materials.

Gas Explosions: A Major Safety Hazard

Gas explosions pose a significant threat to industrial facilities and surrounding communities. When a flammable gas mixture ignites, it results in a rapid and violent release of energy and pressure. The consequences can be devastating, including:

• Injuries and Fatalities: The intense force and heat can cause serious injuries or even loss of life.
• Severe Property Damage: Explosions can destroy infrastructure, leading to costly repairs and operational downtime.
• Community Impact: Beyond the immediate facility, explosions can affect nearby areas, posing risks to public safety and the environment.

CFD's Role in Gas Explosion Analysis

• Simulate Explosion Scenarios: Model the ignition, propagation, and deflagration phases of gas explosions to understand the dynamics involved.
• Predict Overpressure and Blast Effects: Calculate the peak pressure, duration, and force exerted by the explosion to assess the impact on the environment.
• Assess Structural Damage: Evaluate the potential damage to buildings, equipment, and other infrastructure, ensuring robust design and safety measures.
• Identify Safe Distances: Determine safe standoff distances from explosion sources to protect personnel and assets.
• Design Vent Relief Systems: Optimise vent relief systems to safely release pressure during an explosion, preventing catastrophic failures.

Video 3. CFD gas explosion analysis for explosion venting and ATEX

Enhance Your Safety with AFRY’s CFD Expertise in HSE Consequence Analysis

If you’re seeking a reliable and effective method to assess the risks and impacts of potential accidents in your industry, AFRY’s CFD competence in HSE consequence analysis is the solution you need. Our advanced CFD capabilities extend beyond consequence modeling to offer comprehensive safety solutions, including:

• Predictive Analysis: Anticipate and mitigate potential hazards before they become critical issues.
• Engineering Optimisation: Enhance the safety and efficiency of your facilities with tailored design solutions.
• Regulatory Compliance: Ensure your operations meet and exceed industry safety standards.

CFD (Computational Fluid Dynamics) Consultancy

AFRY provides Computational Fluid Dynamics (CFD) services for companies of all sizes, from small businesses to large-scale operations. We can assist you with one-time simple questions or long-term R&D projects.

Our team of over 100 engineers from various countries delivers high-quality computer-aided engineering (CAE) simulations across a range of fields, including:

• Strength & Durability
• Crash Simulations
• Noise & Vibrations
• Thermal Simulations
• Fluid Dynamics.

We use the leading commercial software and hardware to do accurate and reliable simulations that match your needs and expectations. We also give you detailed reports, presentations and suggestions that can help you to make smart decisions and take effective actions. If you want to know more about CFD in HSE engineering or how it can help your industry, please contact us today. We will be happy to talk to you about your needs and offer you a solution that fits your budget and timeline.

This article was written by Ismo Talka, HSE specialist Global Project Services, Process Industries Finland