Numerical modeling of fires on gas pipelines

When natural gas is released through a hole on a high-pressure pipeline, it disperses in the atmosphere as a jet. A jet fire will occur when the leaked gas meets an ignition source. To estimate the dangerous area, the shape and size of the fire must be known. The evolution of the jet fire in air is predicted by using a finite-volume procedure to solve the flow equations. The model is three-dimensional, elliptic and calculated by using a compressibility corrected version of the k - ξ turbulence model, and also includes a probability density function/laminar flamelet model of turbulent non-premixed combustion process. Radiation heat transfer is described using an adaptive version of the discrete transfer method. The model is compared with the experiments about a horizontal jet fire in a wind tunnel in the literature with success. The influence of wind and jet velocity on the fire shape has been investigated. And a correlation based on numerical results for predicting the stoichiometric flame length is proposed.

Research highlights
► We developed a model to predict the evolution of turbulent jet diffusion flames.
► Measurements of temperature distributions match well with the numerical predictions.
► A correlation has been proposed to predict the stoichiometric flame length.
► Buoyancy effects are higher in the numerical results.
► The radiative heat loss is bigger in the experimental results.