Pipeline and Compressor Station Gas Blowdown and Dispersion
To maintain safe operation, Gas Compressor Stations have to occasionally perform gas blowdown operations. These Gas blowdown operations often result in the discharge of large plumes of gas. These gas plumes present flammability, asphyxiation and if ignited thermal exposure hazards to the plant personnel and equipment.
The purpose of a Gas Blowdown and Dispersion Study is to accurately model a facility’s blowdown process, identify the possible hazardous scenarios and evaluate possible hazard mitigation solutions.
Radiation and Combustion Product Modeling
Compared with Analytical Flare modeling methods such as PHAST and Flaresim, CFD is a significantly more accurate and realistic analysis tool. It permits accurately modelling of Evaluated and Ground Flare Designs. These models allow the sizing of Exclusion Zones, Protection arrangement for nearby auxiliary equipment and dispersion of the flare combustion products.
A frequent usage of these models is to provide guidance for Ground and Elevated Flare Vendor RFQ Liaisons. They can offer very accurate and independent Vendor Design Proposal Appraisal.
Onshore and offshore Facility Thermal Dispersion
CFD offers exciting possibilities for the conduct of Thermal Dispersion and HVAC Studies.
Instead of analytical methods, accurate estimates of heating, cooling, air change rates, ventilation efficiency, humidity levels and equillibrium temperature levels can be made for Compressor Buildings, Electrical rooms, Shunt and Transformer enclosures and even complex offshore platforms based on;
- Natural Ventilation
- Forced Air Circulation
- Chilled Air circulation
- Humidity (Dew point control) devices
Radiation and Combustion Product Modeling
Simulation Modeling of Combustion Assist, Flame fusion and inversion versus reality two years later;
Verification of Safe Discharge Locations for Relief Valves
Once constructed, CFD models can provide a wide range of very accurate answers to facility design questions such as the verification of Safe Discharge Locations for Relief Valves. CFD results can also show areas and environmental conditions with potential for accumulation of gas within congested areas or under canopies;
Predicting Gas dispersion behaviour near and over congested plant areas and buildings or alose to air handling units such as Cooling Fans and HVAC intake ducts has always been a challenge when using free-field tools such as PHAST and CANARY.
Example Long Range, Toxic Flammable and Asphyxiating Gas Dispersion
IBEX Analytics specializes in Toxic, Flammable and Asphyxiating Gas Dispersion Analysis. Example shown here outlines our typical LONG RANGE dispersion modeling approach for a semi-heavy density gas (H2S) dispersing across a Mountain range. The same approach is applicable to Flammable and Asphyxiating gases such as Methane and CO2. The example oil production was characterized by its high H2S content. H2S is a hazardous gas which given a loss of containment scenario can disperse and potentially threaten the nearby population concentration centers. The proposed plant site was surrounded on almost all sides by population centers of varying sizes and proximities. The objective of this study was to determine the possibility of H2S gas reaching these population centers following the occurrence of a worst-case loss of containment scenario. The project has defined the potential source of the worst-case loss of containment scenario as the planned Gas Injection unit located close to the proposed Central Production Facility (CPF).
HVAC Ventilation
IBEX Analytics has substantial experiencing models featuring.
- Natural Ventilation
- Mechanical Ventilation
- Cooling and Heating Airstreams
Planning and CFD testing of proposed HVAC System arrangements with specifically positioned Air inlets and exhaust arrangements achieving target airflow rates within different zones while at the same time avoiding low or zero flow regions are among the Offshore and Onshore case studies and projects we have handled in the past.
Air Flow
Achieving the correct levels of airflow analysis are regarded as a critical aspect of most facility designs. IBEX analytics can help you better understand and achieve your airflow targets including;
- Airflow, temperature and humidity targets within equipment rooms
- Modeling air bypass arrangements
- Observing the Airflow rates around buildings located within a site
- Air circulation around exhausts and HVAC air intake ducts
- Air intake gas detection and emergency shutoff Damper arrangements
Accident Investigation
Ibex Analytics has been involved in investigation of US DOJ Texas City Facility, Various US OSHA Accident Investigation Assignments and a number of Oil and Gas and Utility Company investigation cases.
Fire Consequence
Investigated CFD modelling scenarios have included fires and thermal consequences under different cases and conditions such as wind speeds, wind directions, humidity variations, ambient conditions such as temperature and climatic conditions such as rain and snow which have all been among the project topics referred to IBEX Analytics as study topics.
Predicting Fire consequences including rate of convective, radiative and conductive heat transfer and their relationship with rate of fuel supply, rate of Oxygen depletion, soot production and in general heating of materials and structures around the fire have been among the study topics of interest referred to IBEX Analytics by our clients.
In general, material of construction (including concrete, rubbery material, plastic cables, different metallic surfaces, glass windows and their thermal and structural responses towards heating and cooling have also been addressed by the CFD models IBEX Analytics has developed for our clients.