ВПЛИВ ГЕРМЕТИЧНОСТІ ДЕГАЗАЦІЙНОГО ГАЗОПРОВОДУ НА ПРИПЛИВИ ПОВІТРЯ І КОНЦЕНТРАЦІЮ МЕТАНУ

Abstract

concentrations in the vacuum degassing gas pipeline. Methods. Analytical dependencies for determining the absolute pressure, volume flow rate and temperature of the gas mixture in link of degassing gas pipeline and an empirical dependence for determining the volume flow rate of air in the inflows coming through the flange connections of the gas pipeline links were used in the studies. Results. With these assumptions in mind, the formula for determining the gap in the flange joint of the degassing gas pipeline links has been obtained. The results of calculating air inflows and methane concentrations along the length of the horizontal section of the degassing gas pipeline have been presented. Analysis of the results showed that air inflows through the flange joints of the degassing gas pipeline links increase in the direction of the gas mixture flow, while the methane concentration, on the contrary, decreases. In this case, the increase in air inflows is due to an increase in vacuum in the degassing gas pipeline, while the decrease in methane concentration is due to an increase in the volume flow of the gas mixture. Based on the analysis of the methane concentration character of change along the length of the horizontal section of the degassing gas pipeline, the distance from the beginning of the pipeline where the methane concentration value becomes below the permissible value and the probability of ignition of the gas mixture arises. It has been established that methane concentration varies insignificantly along the length of the gas pipeline at normative airflows. Scientific novelty. A formula is derived for determining the size of the gap between the flat rubber gasket and a shoulder of a flange connection of the degassing gas line links, at which the total air inflows in the gas line coincide with the standard value. Practical significance. The determination of the size flange joint clearance of the degassing gas pipeline links makes it possible to calculate the air inflows and assess the tightness of the gas pipeline flange joints on the basis of measurements of the gas mixture volume flow rate, methane concentration and the depression value.