A model to predict the characteristics of fires following the rupture of natural gas transmission pipelines

The gas industry has an excellent safety record in operating high pressure transmission pipelines. Nevertheless, it is important that pipeline operato rs have an understanding of the possible consequences of an accidental gas release, which may ignite, in order to help manage the risks involved and t o develop appropriate standards and design codes for pipeline operations. T he most serious type of hypothetical incident that could affect a high pres sure gas transmission pipeline, involves a full pipe rupture. This paper de scribes the extension and validation of a physically-based phenomenological model of jet fires for predicting the size and position of the fires resul ting from underground gas pipeline ruptures and to predict thermal radiatio n levels around such fires. The application of the complete model to underg round pipeline ruptures has been made possible by the development of a crat er source sub-model which provides suitable input parameters to the fire st ructure calculation. Predictions of the complete model have been compared w ith the results from two full-scale pipeline rupture tests, which has demon strated the performance of the model for a range of realistic scenarios. Th e work was undertaken by an international collaboration of gas companies, a s part of a programme of research to obtain information on the consequences of accidental gas releases from transmission pipelines.