(MATHEMATICAL MODEL TO EVALUATE SAFETY INDICES OF PRESSURE CONTROL VALVES FUNCTIONING AT GAS CONTROL POINTS)
The article suggests and justifies the mathematical model aimed to evaluate the safety indices of the system consisting of a pressure control valve and a safety shut-off valve. The system under review is a part of the gas control points of the regional gas distribution networks and ensures protection of end consumers, in particular against spontaneously arising unauthorized pressure drops. The aim of the research is to introduce a mathematical model, and implement on its basis the system safety index evaluation method into a procedure for calculating the pressure control valve safety parameters, when the last one is fitted with a safety shut-off valve.
The level of consumer protection is regulated and assessed based on the system safety indices. The article provides the emergency parameter evaluation at gas control points. Herewith, the safety indices under review represent the rated values: probability of failure on demand, average time before emergencies, and their frequency.
Features of the gas supply system reliability and maintenance structural diagram are shown. Special attention is paid to the main types of works that are part of the standard scheduled maintenance. It follows from their analysis that the operation process is formally described by the following mathematical objects: random current of system regeneration points, sequence of random regeneration periods, low probability of occurrence of a rare event (an emergency) in each regeneration period. There is an example showing the simplicity of applying the method of determining the system safety indices under review.
It is concluded that the suggested mathematical model, and the method based on it, may be used in the procedure for calculating the pressure control valve safety parameters, when the last one is fitted with a safety shut-off valve.
A.M. Korolenok, DSc in Engineering, Professor, National University of Oil and Gas “Gubkin University” (Moscow, Russia), firstname.lastname@example.org
A.V. Karmanov, DSc in Physics and Mathematics, Associate Professor, National University of Oil and Gas “Gubkin University”, ABKar2007@yandex.ru
S.V. Larionov, PhD in Engineering, Associate Professor, National University of Oil and Gas “Gubkin University”, email@example.com
K.P. Orlova, PhD in Engineering, National University of Oil and Gas “Gubkin University”, firstname.lastname@example.org
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