Project Synopsis
PROCESS was contracted by an engineering firm to perform a plume dispersion analysis for a natural gas pressure relief device (PRD) venting scenario at a pipeline valve station because of the area’s proximity to residential zones.
Project Summary
A multi-disciplined detail engineering firm contracted Process Engineering Associates, LLC (PROCESS) to perform a dispersion analysis for a natural gas pressure relief device (PRD) venting scenario at a pipeline valve station near a compressor station in the Midwest U.S. Given the area’s proximity to residential zones, the primary objective of the study was to assess whether the PRD discharges to a safe location, considering Immediately Dangerous to Life or Health (IDLH) conditions, thermal radiation, and explosion hazards.
The required outputs of this dispersion study included 2D non-Computational Fluid Dynamics (CFD) plots that estimated the boundaries of these hazardous conditions. The analysis considered both the atmospheric PRD relief event as well as a maintenance blowdown venting scenario. The analysis used a dynamic simulator (Aspen HYSYS) to estimate the flow rate for the maintenance blowdown scenario, while DNV PHAST Software was used for the dispersion modeling to assess the hazardous conditions.
The final project deliverables included:
- Contour plots of IDLH conditions, showing downwind distances of concern, overlaid on Google Earth imagery.
- Maintenance blowdown vent curve per HYSYS simulation results
- Radiation plots illustrating ground-level thermal radiation levels, based on the stack height.
- Explosion hazard plots, detailing downwind distances for potential explosion risks.
- A comprehensive Project Presentation Report detailing the design basis, modeling methodology, and key dispersion modeling outputs generated using DNV PHAST software.
PROCESS’ modeling results provided the necessary insights to guide informed decisions regarding the appropriate vent stack height and placement. This information will assist the Client in determining PRD discharge stack height requirements to meet their safety goals, especially considering the proximity of residential areas.
Industry Type
Natural Gas Pipelines
Utilized Skills
- Process simulation
- Plume release dispersion modeling