Heat transfer in large-scale heavy-gas dispersion

Area of Science:

• Environmental Science
• Chemical Engineering
• Atmospheric Science

Background:

• Heavy-gas dispersion is crucial for industrial safety and environmental impact assessments.
• Cold gas releases create density differences, influencing plume behavior.
• The role of ground heat transfer in mitigating these density effects is not fully understood.

Purpose of the Study:

• To investigate the impact of ground heat transfer on heavy-gas dispersion.
• To quantify the reduction in thermally induced density effects.
• To analyze field experiment data for real-world dispersion scenarios.

Main Methods:

• Re-analysis of existing field experiment data.
• Interpretation of measurements from the Desert Tortoise field experiments.
• Analysis of surface heat flux during gas release events.

Main Results:

• Heat transfer from the ground can substantially reduce the density effect in heavy-gas dispersion.
• Surface heat flux decreased by 38% over a 3-minute gas release period in observed experiments.
• The findings suggest a time-dependent reduction in the density effect due to ground thermal capacity limitations.

Conclusions:

• Ground heat transfer is a significant factor that can mitigate heavy-gas dispersion consequences.
• Dispersion models may need to incorporate dynamic heat transfer effects for improved accuracy.
• Understanding these thermal dynamics is essential for accurate prediction of hazardous gas cloud behavior.