Analysis of Additional Factors in Determining the Failure Rate of Heat Network Pipelines

For estimating the reliability of existing and newly developed circuit diagrams of heat networks, a special procedure is applied. By applying this procedure, which uses such input data as the length and operation time of pipeline segments, it is possible to determine the availability factors and probabilities of failure-free operation for a heat network. The aims of this study are to reveal and consider additional factors in determining the failure rate of heat network pipelines and to develop a new procedure for calculating indicators characterizing the reliability of heat supply to consumers. The failure rate of heat network elements depends, apart from the time they have been in operation, on the pipeline wall residual thickness, corrosion activity of soil, pipeline material, failure of a pipeline batch, other (previous) bursts in the considered segment, conduit flooding (flooding traces), and intersections with other utility lines. Additional factors significantly influencing the heat supply reliability, which, however, have not been included in the currently used procedure, are revealed, and an algorithm for calculating the heat network reliability is developed. The influence of the additional factors on the reliability of heat network operation is evaluated proceeding from the field data presented by regional heat supply companies. The influence of additional factors is taken into account in elaborating the new procedure and algorithm for calculating the heat supply’s reliability indicators. The results from numerical and experimental investigations confirmed the possibility of using the obtained functional dependencies for elaborating a procedure of calculating heat network’s reliability taking external factors into account.