RISK ASSESSMENT OF THE EMERGENCY EXPIRATION OF GAS FROM THE GAS PIPELINE UNDER ABNORMAL METEOCONDITIONS OF THE NORTH

Abstract

Low temperatures and abnormal meteoconditions of the North have significant effect both on the frequency of accidents, and on development of accidents. Abnormal weather conditions of the North are characterized by the powerful temperature inversions arising at an anti-cyclone at the expense of the radiation of permafrost soil at extremely low temperatures of air and conditions of air stagnation. These abnormal conditions influence process of gas dispersion in the atmosphere, promoting his delay and formation of explosive concentration of gas at the Earth's surface. As a result the accidents risk of the gas pipelines occurring according to the scenario — the expiration of gas without the subsequent ignition increases. The formed congestion of explosive concentration of gas at Earth can lead further to explosion and the fire.

Methodical approach to risk assessment of the emergency expiration of gas from the gas pipeline under abnormal meteoconditions of the North is presented in article. "The event tree " of the gas expiration from the gas pipeline at low ambient temperatures taking into account abnormal meteoconditions is developed. The implementation frequencies of emergency scenarios at the expiration of gas from the gas pipeline intended for quantitative assessment of accidents risk of gas pipelines at low ambient temperatures are estimated. Influence of temperature inversion on the size of excessive pressure of a shock wave at explosion of a cloud of air-gas mix of methane and to increase in range of the striking factors at failure of the gas pipeline is proved.