Abstract: Based on the characteristics of natural gas pipeline leakage accident, small hole leakage rate model and accident injury model of natural gas pipeline, a system dynamics model was established according to the actual working conditions and personnel distribution characteristics of specific high consequence area to study the dynamic analysis of accident consequences with the intervention of emergency response time change. Meanwhile, the calculation model of personnel death coefficient was established, and Vensim- PLE software was applied to carry out the simulation analysis for the specific high consequence area, and obtained the leakage rate, leakage volume and its change trend with time under different leakage aperture, as well as the change rule of personnel death toll and comprehensive death toll of different evolution accidents with occurrence time. Through the adjustment of the emergency response time parameters, the shortest emergency time to achieve zero death for the small hole leakage accident in the high consequence area was finally obtained, which provided scientific decision support for the safety management in the high consequence area.

Key words: natural gas pipeline, system dynamics, small hole leakage, accident evolution