Hydraulic Reliability Analysis of Gas Networks

Reliability analysis is becoming a key issue in the engineering approach to the operational management of gas networks. However, measuring the hydraulic reliability of a gas network system is not a simple task as it can be related to a variety of parameters and properties of the network. This paper presents a systematic approach to the quantitive assessment and analysis of the hydraulic reliability of gas networks. The measures are calculated from the results of steady-state. It is only necessary to know the complete set of gas flows and pressures at nodes for each modeled situation. Firstly, the node pressure is selected as the state variable. Then, the standardized reliability evaluation curve is drawn in consideration of a variety of concepts and criteria, which shows the relationship between the state variable and the reliability index. In addition, the generalizing function is proposed to calculate an averaged-based value to represent the network. The nodes' demands are used as weights in the generalizing function to weigh each node value in terms of how much demand it affects. Moreover, a distribution of reliability measure values across demand nodes domain is obtained by the meanings of the percentile method. Finally, in a case study, this method is applied in the reliability analysis of a gas network system. The results show that the proposed method can quantify the reliability of gas networks and it may be used in direct support of gas network engineering and operation.