Investigating Effective Parameters in the Hazardous Areas of the City Gas Station (CGS), Through Modeling by PHAST Software

Natural gas (NG) is one of the cleanest and safest sources of energy that is transmitted in a high pressure and must be reduced before entering the City Gas Station (CGS). Identifying the effective parameters in creating the hazardous areas of CGS is essential tothe crisis management. In this study, using PHAST version 7.11 (created by DNV Company), ther has been a consequence modelling conducted in three scenarios at three CGS stations in Qazvin Province, by using actual data including the weather conditions, gas pressure and temperature. The main results for the modeling in all three scenarios were a jet fire, flash fire, and explosion. Based on the modeling results, the highest flame lenght was obtained in the Avaj station which was 10 meters more than the same in others. The highest radiation levels were also in the Avaj station and in about 150 m downwind distance, which could be caused by the longer flame length in that station. The results showed that in the fire jet modeling, an increase in the air temperature could lead to an increase in the gas pressure and temperature, which in this study increased the flame length of 2 meters to 3 meters. However, the flame length and the hazardous area were bigger during the day and summer. The use of the PHAST modeling software can provide useful information including the high-risk operational area, hazard area, high-risk time period (day, night and season) for the management team to respond to emergency situations in industries. In addition, it is necessary to consider the combination of different operating parameters such as the gas pressure and gas temperature with different weather conditions.