Experimental study of jet fire impingment in pipelines

The continuous growth of the global industrial sector has led to an increasing need for the transportation of oil, gas and chemicals through pipelines. The need for compactness of the pipelines along the corridors involves a relatively short distance between one pipe and another, thus leading to a certain degree of risk associated with their potential interaction. Furthermore, as the transported fluids may be flammable, any accidental release due to cracking or leakage in one of the pipelines could lead to an accidental scenario with severe consequences for the population, structures and the environment. A hypothetical accident in one of these pipes can lead to the occurrence of a domino effect, leading to an escalation of effects involving the other pipes. In the case of jet fires, the thermal action produced may lead to a certain risk of ignition of the released material, thus causing a progressive increase in the severity of the consequences. With the development of a jet fire, the high thermal flow that reaches an adjacent pipeline can damage the secondary target by widening the scale of the accident, especially if there is flame impingement. In order to study the thermal evolution of jet fires and quantify the thermal response of a target object placed perpendicular to the flame, a laboratory equipment has been used to obtain data on propane jet fires affecting a pipe containing a gaseous or liquid fluid. In this experimental configuration, pressure and temperature measurements for various propane release rates were performed with the appropriate instrumentation in order to calculate the absorbed heat and convective heat exchange coefficient of the target tube. In order to prevent the occurrence of these accidental fire scenarios, and in particular jet fire, a special type of passive fire protection, such as intumescent coatings, capable of forming an insulating layer when stressed by an external heat source, was also examined.