PSI - Issue 59

Ya. Grudz et al. / Procedia Structural Integrity 59 (2024) 745–749

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Ya. Grudz et al. / Structural Integrity Procedia 00 (2019) 000 – 000

other hand, gas losses associated with technological costs of transportation are increasing, in particular, caused by the violation of the tightness of gas mains and partial changes in the modes of operation of the gas transportation network (Kovalko et. al., 2002; Kryzhanivskyi et. al., 2006). As is known (Grudz et. al., 2009) losses from undersupply of gas to consumers significantly exceed losses associated with technological costs for its transportation. Therefore, the task of choosing the optimal ratio between gas transportation network maintenance costs and the reliability of gas supply and gas pumping is now particularly relevant. In order to ensure the maximization of the load of the gas transportation system under known technological limitations and to guarantee the continuity of gas supply in the specified volumes, the following tasks must be performed: - Load forecasting during a certain time interval (day, week, etc.); - Distribution of a set of elements of the gas transportation system that are in operation; - Search for a rational distribution of the total load by elements of the gas transportation network, which minimizes the total cost of pumping. These three problems are closely related. In this regard, the mentioned problems are combined under the general name of gas pumping planning. Solving the set tasks is impossible without improving the organization and management of the operational maintenance process under the following conditions (Yakovlev et. al., 1993): - With the known location and firm fixation of the specified sections of gas pipelines by repair and operation units; - With fixed strategies and regime of control and recovery measures; - With the known total capacity of the maintenance and operation unit, the level of its mechanical armament and staffing; - If there is information about the state of the system as a whole, about the influence of external random uncontrollable factors. The present paper aims to optimise the management of the maintenance process of the gas transportation system to provide consumers with energy carriers under the conditions of using the available means at minimum costs and in the shortest possible time. 2. Research methodology By the process of operation of the K-th repair and operation unit in the maintenance and repair system, we will understand the development of a certain system complex of works K V R performed to eliminate damages that accidentally appear during operation and failures on the linear part, as well as the implementation of a number of operational measures character. The purpose of the operation of the maintenance and operation unit can be specified taking into account the previous remarks: achieving the specified volume and quality indicators characterizing the flow of applications for maintenance and repair, with the lowest costs and in the shortest possible time. Due to the fact that these tasks sometimes contradict each other, three approaches to setting the task of improving service efficiency have been formulated (Buslenko 1977). The first approach consists in the fact that in the process of developing optimal organizational and technological solutions, the main goal is to achieve minimum costs and costs for carrying out repair, restoration and preventive works during some fixed maximum permissible period of time. The second approach consists in the desire to carry out the set of necessary works as quickly as possible with some restrictions on the total capacity of the units involved. The use of one or another approach significantly simplifies the process of finding optimal solutions due to a sharp reduction in the number of considered alternative options for organizational and technological support of maintenance, reduction of computing operations. However, when considering the system without taking into account the influence of various controlled and random factors, outside of their system connection, it is unlikely to find the global optimum of the objective function under study. In this regard, the task of finding optimal ratios of volume, quality and time indicators without fixing any of them is of greatest interest. In other words, the third approach to setting the task can be formulated as follows: to carry out the complex of necessary works in such a