Numerical Simulation Analysis of Fire Hazard from Leakage and Diffusion of Vinyl Chloride in Different Atmospheric Environments

Yuchuan Liu,Jian Wang

doi:10.3390/fire5020036

Abstract

In this paper, using the numerical simulation analysis software MATLAB and Fire Dynamics Simulation (FDS), the corresponding gas leakage diffusion model and turbulence leakage diffusion module were used to study the diffusion law and fire hazard of vinyl chloride monomer after leakage in different atmospheric environments. The concentration distribution results for vinyl chloride diffusion obtained by numerical simulation were compared and analyzed. The fire hazard area of leakage diffusion is defined by the hot fire concentration of vinyl chloride gas, and the influence of the gas-phase oxidation reaction of vinyl chloride on leakage diffusion is also discussed. The conclusion shows that as the atmospheric environment stabilizes, the peak concentration of vinyl chloride leakage and the diffusion area decrease correspondingly, the fire risk area gradually shrinks, the fire risk decreases, the affected area gradually expands, and the toxicity risk increases. When it is not in a stable state, the formaldehyde derived from the gas-phase oxidation reaction aggregates together with vinyl chloride to form a mixed gas cloud. Although the scope of influence is reduced, the concentration of harmful gases in the area is higher, and the fire risk of the mixed gas is increased.

Highlights

When the concentration of vinyl chloride exceeds the concentration of hot fire, if it encounters an open flame or electric spark, it is very likely to cause secondary disasters, such as a fire or explosion [2,3]
Using MATLAB numerical analysis software and the Gaussian plume model, we examined the spatial distribution of the concentration field of the vinyl chloride monomer at different atmospheric stability classes, from unstable to stable, namely class A, C, and E, and performed continuous leakage simulation analysis
Compared with when the atmospheric environment is unstable, the wind speed has a significant impact on the form, speed, range, and concentration distribution of the gas cloud formed by the leakage and diffusion of vinyl chloride

Summary

Introduction

The petrochemical industry is fundamental to the national economy. In recent years, with the continuous advancement of science and technology, the development trend has become increasingly rapid. In 2019, Liu et al [10] used ALOHA software to simulate and analyze the influence of the size of the leakage opening of a vinyl chloride storage tank and the environmental wind speed on its leakage spread and explosion hazard zone. Research on the leakage and diffusion of vinyl chloride gas mainly focuses on the initial conditions and the influence of environmental factors, the characteristics and mechanism of explosions, the analysis of environmental human hazards and the extent of accident damage, etc., and related research on the consequences of its gas-phase reaction. In this paper, we selected the corresponding gas diffusion theoretical model and turbulence leakage diffusion model and used the numerical simulation analysis software MATLAB and FDS to deeply study the diffusion law and accident evolution characteristics of vinyl chloride under different levels of atmospheric stability, and analyzed the risk of its leakage and diffusion. The development trend and hazard prediction of vinyl chloride leakage accidents are very important for the safe production and application of vinyl chloride in chemical enterprises, leakage prevention management, emergency treatment after accidents, rescue and evacuation, etc

Diffusion Theory Model

MATLAB Numerical Analysis

FDS Numerical Simulation

Discussion

Limitations and Future

Conclusions