Vestnik of Samara State Technical University. Technical Sciences Series

The article proposes a method for forecasting and approximate calculating the two-component systems characteristics state diagrams. The results for 200 salt systems with a common cation and 100 with a common anion systems statistical analysis of fase diagrams are presented. In this paper, the authors propose to consider two signs of the eutectic points presence in binary systems and a method for approximate calculation the eutectic point temperature and concentration values. The first criterion for the presence or absence of eutectic points in the system is determined using specific, isobaric heat capacities of the components. The second criterion is based on the well-known fact that entropy values difference for components of eutectic systems are greater than entropy differences for components of systems with continuous series of solid solutions. A method for approximate calculating the temperatures values and the composition of two-component salt systems eutectic points, in which there is no intermediate chemical interaction between the components, is given. A comparative analysis of the calculations results according to the methodology proposed by the authors and the eutectics thermodynamic characteristics values obtained using the Schroeder-Le Chatelier equation is carried out. The adequacy of the proposed model for the analysis and determination of the thermodynamic characteristics of two-component salt systems is confirmed by the calculations results of the eutectics composition and temperatures of 120 two-component systems with average errors, which amounted to 6% in concentrations and 7% in temperatures. Based on the proposed approximation procedure, a calculation program in the Pascal language was created in the Delphi visual environment with a user interface. One of the advantages of this environment is that the executable modules of programs created in it do not require equipping the computer with additional software, except for the presence of an operating system.

A new approach to the system analysis of a structured complex of recycling (CR) of oil waste (OW) is proposed based on the Data Envelopment Analysis method, which allows solving the problem of choosing optimal processing technologies according to heterogeneous criteria of resource potential, environmental safety, resource and energy saving, and integrated efficiency. New classifications are presented: OW by sources of formation in the oil and gas industry and methods of recycling OW. An analysis of the systemic problems accompanying the technological processes of processing non-carbon dioxide has been carried out, which confirm the need to consider non-carbon dioxide storage facilities and technologies for their processing within a single system, consisting of two subsystems of disposal and processing. The system-wide properties of the OW CR and the interrelations of its main elements are analyzed, the presence of stable connections between the elements of the system and integrative qualities are revealed.

A methodology for system analysis and optimization of the OW CR has been developed, consisting of 10 consecutive stages and including the development of databases and special software, multifactor analysis and optimization, the use of artificial neural networks to increase the speed of calculations, and the development of an information support system for making scientifically based management decisions.

The results of testing the methodology for analyzing the CR, consisting of 90 OW storage facilities and 14 processing technologies located within one region, are shown. The results of solving two problems of optimizing the non-carbon dioxide processing system according to the criterion of maximum comprehensive efficiency, taking into account constant and variable scale effects, were obtained.

The proposed approach can be extended to other regions of the Russian Federation with a developed oil and gas industry, where there is a need to take urgent measures to eliminate waste storage facilities and improve the environmental situation.

A lot of problem situations arise in our everyday life, that worsen quality of life, reduce labor productivity. Modern science does not have decision-making technologies in problem situations under conditions of uncertainty, when the subjects themselves need to decide what to do, and not how to do it. The only theory that proposes actors a new approach to managing the problem situations solving is the theory of intersubjective management, proposed at the beginning of the XXI century. The fundamental difference between intersubjective management and classical one is that management functions are assigned to people themselves, immersed in a problem situation and actively acting (actors). In the process of decision making in a problem situation actors need methodological and informational support. For this purpose, a decision support system is developed that uses methods and tools of slightly formalized subject areas. When choosing models, methods and tools that support actors in the process of problem situation solving, the features of the group decision-making process in intersubjective management are taken into account. The choice of methods for application by actors is also influenced by the subjective component, i. e. their personal characteristics and preferences, knowledge, and skills. Decision support system design is based on the Nonaka-Takeuchi knowledge management model.

This article continues a series of publications devoted to the problems of early state diagnosis of the combined journal-and-thrust bearing of the turbo-pump unit of the liquid-propellant rocket engine NK-33, which is a critical node of the power plant under consideration. The proposed approach is based on the idea of replacing the standard induction sensors of the turbo-pump rotational speed currently used in turbo-pump unit by specially designed single-coil eddy current sensors with sensitive elements in the form of a segment of a linear conductor. The transducers are placed in the same mounting holes as the standard rotor’s speed sensors and their sensitive elements are oriented relative to the tooth of the measuring disc on the controlled shaft in such a way that the tip of the tooth remains in the sensitivity zone of both sensors during all possible movements of the shaft. The change in the axial position of the disk caused by the displacement of the rotor shaft in the radial thrust bearing during its destruction is determined on the basis of combined processing of the eddy current sensors’ output signals during the passage of the tooth under the sensors’ sensitive elements. The implementation of the standard rotor’s speed measuring function in the main and backup channels is ensured by fixing the moments of the tooth passage through the geometric centers of the sensitive elements of the first and second sensors in the cluster. The article is devoted to estimation of errors of the shaft's axial movement measuring in the channels of the system for monitoring the state of radial thrust bearing of the NK-33 liquid rocket engine’s turbopump unit. In particular, the random and systematic components of the basic error caused by the interference, the finite sampling frequency and the chosen method for calculating the desired shaft movements are given.

This paper proposed methods for determining mechanical stresses in the inductor of a synchronous electric machine with magnetoelectric excitation and incorporated V-shaped permanent magnets, intended for use as an auxiliary generator of a gas compressor station driven by a gas turbine engine. Along with the advantages: high energy efficiency, large electromagnetic torque and specific power, the ability to create a small airgap between the stator and the rotor, machines with such an inductor design have a significant drawback - large magnetic flux dissipation in the area of ​​external and internal saturation bridges, which is all the more significant as the bridges are wider. To decrease leakage fluxes and ensure acceptable energy performance, it is desirable to reduce the width of the bridges, but this weakens the mechanical strength of the rotor.

Analytical models of two levels are proposed for assessing mechanical stresses in the inductor design, on the basis of which the configuration option for permanent magnets and rotor pole pieces is selected. The first level model assumes knowledge of the inductor geometric dimensions, which can be obtained at the stage of the electric machine electromagnetic calculation. Therefore, it is more suitable for the estimated calculation of mechanical stresses on external bridges. The second-level model was obtained using analytical dependencies based on the analogy of a magnet-pole tip system with a beam with rigid clamping on supports and a distributed load along it. It is suitable for determining mechanical strength during optimization design, when it is necessary to operate with large volumes of data.

The results of calculating mechanical stresses using analytical models are checked and refined by solving the strength problem using the finite element method in the Ansys Structural software package.