Key outcomes
- Operational personnel safety enhanced
- Capital costs minimised
- Risks rapidly mitigated
Gas extraction or refining facilities utilise flares to combust large amounts of gas in the event of a critical equipment failure. Emergency gas flares pose a risk to nearby personnel due to high temperatures and thermal radiation exposure. The risk of personnel exposure to extreme thermal radiation increases due to environmental factors such as wind strength and direction.
Figure 1:Temperature coloured plume of a >500MW emergency ground flare during a 100 km/h prevailing wind. The red region is the hottest part of the plume, and blue the coldest. The brown dots represent an access boundary around the flare. The plume impacts the nearby buildings.
Synergetics have undertaken computational fluid dynamics (CFD) simulations of both flare stacks and flare pits. In the study presented here a flare pit was in close proximity to equipment, and the client was seeking a rapid risk assessment of a flare during extreme winds and a conceptual design for a protective solution.
CFD simulation of a gas flare requires accounting for sub-zero temperatures, high mass flow rate gas supply, complex combustion processes with multiple fuel components, and the capability to determine thermal radiation distribution.
Figure 2:The addition of a solid barrier between the flare pit and the buildings increases localised mixing and the height of the plume. This results in the plume passing significantly higher over potential access locations and buildings. The barrier also dramatically reduces radiation impacts.
Synergetics utilised CFD to simulate a >500MW gas flare under the influence of multiple wind conditions. Several low capital cost options were quickly assessed to improve site personnel safety. Working with the client we identified a solution which could be rapidly installed at low cost.
For further examples of combustion modelling see our thermal processing sector page.