A methodology to determine the target reliability of natural gas pipeline systems based on risk acceptance criteria of pipelines

The reliable operation of the natural gas pipeline system is directly related to natural gas supply security, and it is vital to determine the target reliability of the natural gas pipeline system when assessing whether the system is reliable. In this study, a methodology to determine the target reliability of natural gas pipeline system based on the risk acceptance criteria of pipelines is proposed, and the methodology consists of three parts. Firstly, the risk acceptance criteria of the natural gas pipelines are determined based on the existing standards. Secondly, the failure consequence model of natural gas pipelines considering the pipeline properties and surroundings is developed, and the corresponding allowable pipeline failure probabilities are calculated according to the risk theory. Finally, the evaluation model of the gas supply reliability for natural gas pipeline systems considering the unit's failure and hydraulic characteristics is developed, and the target reliability of natural gas pipeline systems is calculated by employing the allowable pipeline failure probabilities. Furthermore, a real natural gas pipeline system is employed to determine its target reliability, and the target value is compared with the actual value of the gas supply reliability. Based on the compared results, the corresponding measure to improve the gas supply reliability is proposed.