Increase of the technogenic and ecological safety of the natural gas transportation due to displacement of explosive mixtures with nitrogen

Abstract

Purpose: To ensure technological and environmental safety it is proposed to use the technology of purging pipeline with compressed nitrogen. Design/methodology/approach: The purpose of the calculation is: to get the graph of the concentration distribution (in volume fraction) of nitrogen and natural gas components depending on the distance from the injection point of nitrogen and the duration of the purge process, to determine of parameters of a non-stationary process, and to establish the optimal parameters of the purging process under conditions of the given flow chart. Findings: In the process of displacement of natural gas, the velocity of the front of nitrogen is one of the main quantities that significantly affect the quality of displacement. To assess the actual technological schemes for transporting natural gas, it is necessary to select the velocity of displacement of explosive mixtures. Research limitations/implications: This technology should be implemented in the conditions of a nitrogen pressure higher than 0.25 MPa. Practical implications: Most favourable conditions for the complete displacement of air and subsequent replacement of nitrogen with natural gas were observed for pressures higher from 1.0 to 1.5 MPa. Originality/value: Complex calculations of the volume of air displaced with nitrogen and natural gas in the process of filling the pipeline were conducted in the research. Boundary conditions on the concentration of the mixture of nitrogen and natural gas were identified.