Evaluation the Extent of Explosion, Ignition and Gas Leakage Consequences in Cylinders Containing 26.2-Liters of Liquid Gas, with Passive Defense Approach

Document Type : Original Research

Authors

PhD Candidate of Occupational Health Engineering, Occupational Health Research Center, Qom University of medical Sciences, Qom, Iran

Abstract

Background and Aim: Knowing the maximum radius of fire, explosion and emission of toxic gases, can play a very important role in the operationalization of urban passive defense requirements in order to reduce vulnerability in accidents. The main objective of this study is modeling the extent of explosion, ignition and gas leakage Consequences in cylinders containing 26.2-liters of liquid gas, with passive defense approach.
Methods: In this study, the effective factors on discharge and release of gases are described and ALOHA software has been used as one of the most suitable software for modeling the gas emissions of LPG (Liquefied Petroleum Gas) cylinders. Based on the modeling results, the emergency response program during gas leakage is presented.
Results: When the gas leaks from LPG cylinder with 1-inch vent valve, the cylinder will be empty in one minute and the gas concentration will be 12600 ppm (60% LEL) and 2100 ppm (10% LEL) up to 11 meters and 35 meters from cylinder, respectively. In the case of vapor cloud explosion, the explosive wave pressure will be about 3.5 psi, up to 13 meters from the reservoir which may cause serious damage, and it will be equal to 1 psi, up to 25 meters from the cylinder which has strength of breaking the glass. In case of furious fire, fire flame with eight meters’ length is created, with thermal radiation of about 10 Kw/m2 and 5 Kw/m2 up to 10 meters and 12 meters from the cylinder, respectively which can cause second-degree burns. In the event of BELIEVE, a fireball will occur with a diameter of 14 meters within 2 seconds, with thermal radiation of about 10 Kw/m2 up to 53 meters from the cylinder.
Conclusion: The consequences of flaring and explosion of LPG gas, up to 35 meters from cylinder, are the most serious threat for human health, if gas leaks from a cylinder. Optimal positioning of gas cylinders will have an important role in limiting the harmful effects of hazardous emissions in military barracks.

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