PARAMETER DEFINITION OF THE AVERAGE GAS PRESSURE IN THE SECTION OF THE PIPELINE

Abstract

Parameter of medium pressure P^cp is required, for example, to estimate the mass of natural gas involved in the formation of a fiery torch in case of emergency destruction of the main pipeline. However, the methodology for a systematic calculation of this parameter in the current methodological and normative documents, the author has not found. Despite the apparent simplicity of the problem, the analysis has shown that the parameter P^cp depends primarily on the performance Q_TU of pipeline, the pressure P_H at the beginning of the emergency area and the pressure P₀ at the point of the destruction of the pipeline, which in turn are determined by the dependencies from the pressure P_K in the end of emergency site, the relationship of the lengths L₁/L emergency areas, inner diameter d_BH of the pipeline, it's the roughness k₀, the hydraulic resistance coefficient X, the gas flow velocity w, it's the density in the working p in the normal p_H and in the standard conditions p_c, and more than twenty parameters characterizing the state of a gas in terms of its transport and depressurization of the pipeline. In some cases there is no justification of the calculated transitions, for example, to calculate the final pressure Р_к2 gas at the second site crash in the presence of data for the initial pressure P_h1 first site crash. Calculations of these parameters regulated in several normative documents, which introduces uncertainty in the choice of the calculation scheme and is accompanied by the production of different calculation results. Calculations of other parameters recommended by the standard methods are complex, three-dimensional routine, require access to specialized software products that are not available in the current engineering activities. The subjects of this article are refinement of these problems, the rationale for the recommended design solutions and adapting them in a simple, systematic methodology for calculating the average pressure at different sections of the main pipeline.