Consequence modeling of explosion at Azad-Shahr CNG refueling station

Safety of people has been the most important concern since the onset of commercial use of Compressed Natural Gas¹ as a novel type of vehicle fuel. Provided a car vessel bursts, irreversible consequences will surface. The most important hazard threatening people and their properties in CNG distribution stations is pressurized natural gas in station storage vessels and car vessels. Storage vessels are far from people; however, they may damage other properties such as pipes, valves, electrical equipment, and etc. Owing to the distance between storage vessels and the hive, the risk is not considered a big concern; on the contrary, car storage vessel is very close to the passengers sitting in the car and those standing around the car. The proximity heightens the risk as the consequences caused by vessel burst can be more catastrophic than the former condition. Taken together, the car CNG vessel burst may be regarded as the most hazardous event at CNG distribution centers. It is believed that modeling the mentioned events can illustrate risky conditions. The present study was formulated in order to model one of such accidents occurring in Azad-Shahr in the winter 2010. The obtained results provided useful points and recommendations like the minimum safe distance from rupture center depending on such outcomes as overpressure, types of fire, or toxic release. The recommendations provided by the present study can prevent people from calamitous events and they can be adopted so as to reduce severity of possible events.