INVESTIGATION OF THE PROCESS OF GAS LEAKAGE UNDER PRESSURE IN THE NON-STATIONARY PROCESS OF MOVING IT IN THE PIPELINE

Surveys of underground gas pipelines have shown that their service life mainly depends on the corrosion resistance of the base metal and welded pipe joints, as well as the nature of the destruction of the metal surface in places with damaged insulation. Preliminary study of the operating conditions of underground gas pipelines allowed to conclude the need for comprehensive studies of the deformable system "pipe - soil mass" by modern methods of mechanics of underground structures and mechanics of corrosion failure to prevent depressurization of gas pipelines. In the practice of construction, the issues of interaction of pipelines with the soil are insufficiently studied. Therefore, there are no clear and proven decisions on the selection or determination of the main characteristics for the calculation and analysis of underground pipelines. Taking into account the corrosion activity of the soil, which is estimated from time to time on the new gas pipeline, the composition and physical and mechanical properties of soils and their dynamics significantly complicates the calculation scheme, as there are many additional, time-varying parameters that are determined experimentally. The list of the most important factors that determine the corrosion activity of soils, which are the structure and particle size distribution, humidity, composition of the soil electrolyte, total acidity or alkalinity of the soil, the concentration of hydrogen ions, air permeability Regularities of the process of leakage of real gases through holes and nozzles under pressure are based on mathematical modeling. Basic mathematical models are based on classical equations that describe the process of gas motion in a pipeline, namely the equations of motion, the equations of continuity and the equations of energy. The equation of motion is based on the principle of superposition of forces acting on an element of matter in a gas stream. During the operation of gas pipelines there are leaks, which manifest themselves in the form of gas leaks of varying intensity in the environment, pose a threat of environmental pollution and are potentially dangerous for system failures.